North Face Research Articles

FOREST ANALYSIS IN THE LANDSCAPE CONTEXT AT SÃO BARTOLOMEU RIVER BASIN, VIÇOSA-MG

ABSTRACT The reduction of forest areas in recent years has influenced landscape fragmentation, compromising ecosystem functions. The natural forest, in addition to maintaining biodiversity, is capable of improving the hydrological conditions of the watershed. This study aimed to characterize the landscape structure of the remaining forest fragments in the São Bartolomeu river basin, at the Zona da Mata of Minas Gerais State, and to assess their physiographic and pedological representativeness. The study area is responsible for most of Viçosa’s water supply, while it is undergoing an urbanization process, reinforcing the need for ordering the use, besides the evaluation of priority areas for conservation. The studies related to the landscape structure were based on the metrics of forest fragments. The representativeness was analyzed regarding the aspects of topographic compartmentation, slope faces, and soils, using the Chi-square test. The natural forest presents fragments varying from medium to large size, with satisfactory proximity between them. However, the forest patches have irregular shapes, favoring the edge effect with a tendency towards irregularity as the fragment size increases. The results of the physiographic and pedological representativeness indicate that the land uses are dependent on the location in the landscape. According to the statistical test, the forest occurs less frequently than expected on the river terraces (48.3%) and convex slopes (2.3%), as well as on the Red-Yellow Acrisols (53.1%), and on the north (28.5%) and west (20.9%) faces. For urban planning and biodiversity conservation purposes, it is recommended to balance the forest area in the different compartments of the landscape, giving priority to the connection of forest fragments.

Geomorphology of the high-elevated flysch range – Mt. Babia Góra Massif (Western Carpathians)

ABSTRACT A detailed geomorphological map of the Mt. Babia Góra Massif (1725 m a.s.l.), at a scale 1:10,000 is presented. A slope, glacial, periglacial and fluvial features were mapped on the base of the coupled field studies and LiDAR DEM analyses. This study underlines the complexity of rock slope failures (RSFs), in shaping the morphology of compact and isolated upland, exhibiting one of the highest incidences of RSFs yet recorded in Europe (29% for a whole massif, and 45% for the north face). A total of 212 RSFs were mapped of which 18 failures are large landslides (>0.25 km2), among them is one of the largest known (2.6 km2 and 150 × 106 m3) in the Polish Flysch Carpathians. The mapping and Schmidt-hammer results shed light on the problem of glacial relief of the massif, documenting the remnants of glacial deposits beyond the tongues of landslides in the Szumiąca Woda valley.

Lithobiont-dependent ionic composition in runoff water

Abstract Rock dwelling organisms (lithobionts) such as cyanobacteria (prokaryotes) and chlorolichens (eukaryotes) abound in the Negev Desert, where they cover almost all calcareous bedrocks and rock particles (cobbles, boulders). In a small limestone watershed in the Negev Highlands, cyanobacteria inhabit the south-facing (SF) bedrocks, epilithic lichens (accompanied by endolithic lichens) inhabit the north-facing (NF) bedrocks, while endolithic lichens cover most of the cobbles and boulders in both aspects. In order to study their contribution to runoff water, a pair of runoff plots was established on habitats with cyanobacteria, endolithic lichens, and epilithic lichens. Rain and runoff were collected during the hydrological year 2006/07, and the chemical composition (Ca, Mg, Na, K, Cl, SO4, HCO3, Si) of the rain and runoff water was analyzed. Several patterns were observed: (a) as indicated by Si, more dust accumulated on the bedrocks; (b) all substrates exhibited high amounts of Ca, and HCO3; (c) while SF-bedrocks showed enrichment in K, both bedrocks (and especially the NF bedrocks), as well as the NF boulders showed an enrichment in Mg. While the enrichment in Ca and HCO3 can be explained by the contribution of the limestone parent material, the enrichment in K and Mg can be explained by the contribution of the living lithobionts, with K being mainly contributed by the cyanobacteria and Mg mainly by the epilithic lichens. Ion enrichment may therefore be aspect-dependent, reflecting the lithobiont distribution within the drainage basin, partially explaining the enrichment in K and Mg previously recorded in runoff water from the Negev.

Photo-sensitive "flip-flop" characteristics of the developing Narcissus plant (daffodil phototropism).

The developing Narcissus pseudonarcissus plant (daffodil) is shown to face towards a preferential direction (east, south, west, or north, in that order) before flowering. Said directionality is accomplished by stem bending, a phototropic response mechanism, which is sensitive to partial blocking of the available sunlight from the local environmental. Polar distribution diagrams show that with partial environmental shading from the north, east, south, or west, the developing daffodil plant always excludes facing in that direction, to absorb maximum available sunlight. Stem buckling experiments, equivalent to stem bending, are presented measuring the Euler buckling exponent n = - 2.1 for daffodil flower stems, in good agreement with theory, r = 0.99. Individual flower stems are capable of generating 2-3 lbf of vertical force, which explains the plants ability to penetrate frozen ground cover. Results from 193 daffodil flower stems are presented, showing that 61.7% face East [95% CI 54-70%], 17.1% face South, 15.0% face West, and only 6.2% face North [95% CI 2-10%], depending strongly on the partial shading effect of the surrounding environment.

Complicated Green Advertising: Understanding the Promotion of Clothing Recycling Efforts

The fashion industry, a major global polluter, has been paying more attention to the environmental and ecological impacts of clothing production. A subset of established brands — some supported by the US group Cotton Incorporated — have pushed programmes where denim and other types of clothing can be turned in at a store, collected, and then sent for recycling. Often, these recycling efforts are supported with promotional offers that allow customers to purchase new items at a discount. This is potentially paradoxical as in this way recycling is used to promote further consumption. This paper interrogates the promotion of recycling programmes from four US brands: American Eagle, H&M, Madewell and The North Face. To do so, this paper uses a textual analysis and deconstruction of the brands’ websites and in-store advertising, as well as a KWIC analysis of Twitter messages. By examining the tangible communication components that support the recycling efforts, this analysis highlights the ‘complicated greenness’ (Hepburn, 2013) within the process as consumer incentives for recycling promote further consumption and often leave consumers confused as to the environmental efficacy of such practices. This paper offers considerations for ways fashion brands might be more impactful in their foray into environmentalism.

Novedades florísticas en la vertiente Norte de Sierra Nevada (Granada, España)

Se presenta un listado de 14 taxones que son novedosos o de interés para Andalucía y que han sido recolectados en la cara norte de Sierra Nevada (Granada). Se incluyen datos de la biología, corología y ecología de todos ellos, además de algunas fotos de especies significativas.

The making of “asli” Sumba woven cloth: how globalising “intangible heritage” impacts women’s roles

ABSTRACT This article discusses how the production of “original”/“asli” commodity through a local/global dialectic in how “intangible heritage” is defined and how contemporary global market-facing Sumba weaving contributes to shifts and contradictions in gender roles as they are shaped simultaneously through local community needs and through a global facing westernised patriarchal business ethos. The increasing global north facing integration of global south production communities into the world markets for instance, leads to a masculinisation of management and global facing leadership while along with a feminisation of the local production process. Evidence for our observations were drawn from over 50 in-depth interviews and onsite observation during field visits to the site.

Thermal performance impacts of vented EIFS assemblies in the cold climate of Southern Ontario

One of the key improvements in EIFS/ETICS is the addition of geometrically-defined drainage cavities at the rear of the continuous insulation layer to allow water that has penetrated the outer EIFS lamina to drain out by gravity to the exterior; and to provide an opportunity for enhancing the convective drying ability of the wall assembly by introducing air flow and moisture exchange between the cavities and the exterior environment. EIFS assemblies with such cavities can be either vented or ventilated depending on the vents size, location and distribution. The integration of these cavities has raised questions regarding their impacts on the thermal performance of wall assemblies constructed of EIFS with such cavities. The principal objective of this research was to evaluate the reduction in the whole-assembly's effective thermal resistance due to the use of vented EIFS in lieu of face-sealed EIFS. Thermal numerical simulations were conducted on models that were validated against experimental results of full-scale field tests conducted in the cold climate of southern Ontario. Reductions in the thermal resistances of vented EIFS assemblies were observed in the range of 1.4–5.3% and 0.1–4.6% for south and north facing walls, respectively. Reducing the spacing between the cavities further reduced the thermal resistances due to increased ventilation. It was also found that the thermal resistances of the lightly and medium insulated south-facing EIFS were lower than their northern counterparts, mainly due to the thermal storage ability of the construction materials. However, heavily insulated EIFS reduces this flux of heat and eventually the south-facing walls' thermal resistances overcome their northern counterparts.

THE CUSTOMER OF THE FUTURE: THE PSYCHOLOGICAL, TECHNICAL, AND EXPERIENTIAL STRATEGIES

AbstractThis article examines how the most successful companies have become increasingly customer‐centric, especially as the evolve to better serve the customer of the future. It is based on my research for a new book, The Customer of The Future: 10 Guiding Principles For Winning Tomorrow's Business, as well as research studies from such organizations as Temkin Group, Gartner, Forrester Research, and McKinsey. The approach used by the profiled companies can be applied to the work of leaders in all sectors of society's organizations.The article divides the customer experience into three categories: psychological, technical, and experiential. Within psychological, examples are drawn from Amazon, Capital One, and Pixar; within technical, from Sephora, Best Buy, and Macy's; and within experiential, from Hasbro, Lyft, and Allstate. The impact of artificial intelligence is noted, with examples from The North Face and Macy's; and the use of predictive analytics by ride‐sharing firm Lyft is explained. Particular importance in the article is given to the strategic and ethical use of customer data. For instance, Allstate's CEO Tom Wilson mentions that customer data is the new currency, and his company is building ways that people can be better aware of their personal data and accounts online.

Multi‐dimensional biodiversity hotspots and the future of taxonomic, ecological and phylogenetic diversity: A case study of North American rodents

AbstractAimWe investigate geographic patterns across taxonomic, ecological and phylogenetic diversity to test for spatial (in)congruency and identify aggregate diversity hotspots in relationship to present land use and future climate. Simulating extinctions of imperilled species, we demonstrate where losses across diversity dimensions and geography are predicted.LocationNorth America.Time periodPresent day, future.Major taxa studiedRodentia.MethodsUsing geographic range maps for rodent species, we quantified spatial patterns for 11 dimensions of diversity: taxonomic (species, range weighted), ecological (body size, diet and habitat), phylogenetic (mean, variance, and nearest‐neighbour patristic distances, phylogenetic distance and genus‐to‐species ratio) and phyloendemism. We tested for correlations across dimensions and used spatial residual analyses to illustrate regions of pronounced diversity. We aggregated diversity hotspots in relationship to predictions of land‐use and climate change and recalculated metrics following extinctions of IUCN‐listed imperilled species.ResultsTopographically complex western North America hosts high diversity across multiple dimensions: phyloendemism and ecological diversity exceed predictions based on taxonomic richness, and phylogenetic variance patterns indicate steep gradients in phylogenetic turnover. An aggregate diversity hotspot emerges in the west, whereas spatial incongruence exists across diversity dimensions at the continental scale. Notably, phylogenetic metrics are uncorrelated with ecological diversity. Diversity hotspots overlap with land‐use and climate change, and extinctions predicted by IUCN status are unevenly distributed across space, phylogeny or ecological groups.Main conclusionsComparison of taxonomic, ecological and phylogenetic diversity patterns for North American rodents clearly shows the multifaceted nature of biodiversity. Testing for geographic patterns and (in)congruency across dimensions of diversity facilitates investigation into underlying ecological and evolutionary processes. The geographic scope of this analysis suggests that several explicit regional challenges face North American rodent fauna in the future. Simultaneous consideration of multi‐dimensional biodiversity allows us to assess what critical functions or evolutionary history we might lose with future extinctions and maximize the potential of our conservation efforts.

Observations on the May 2019 Joffre Peak landslides, British Columbia

Two catastrophic landslides occurred in quick succession on 13 and 16 May 2019, from the north face of Joffre Peak, Cerise Creek, southern Coast Mountains, British Columbia. With headscarps at 2560 m and 2690 m elevation, both began as rock avalanches, rapidly transforming into debris flows along middle Cerise Creek, and finally into debris floods affecting the fan. Beyond the fan margin, a flood surge on Cayoosh Creek reached bankfull and attenuated rapidly downstream; only fine sediment reached Duffey Lake. The toe of the main debris flow deposit reached 4 km from the headscarp, with a travel angle of 0.28, while the debris flood phase reached the fan margin 5.9 km downstream, with a travel angle of 0.22. Photogrammetry indicates the source volume of each event is 2–3 Mm3, with combined volume of 5 Mm3. Lidar differencing, used to assess deposit volume, yielded a similar total result, although error in the depth estimate introduced large volume error masking the expected increase due to dilation and entrainment. The average velocity of the rock avalanche-debris flow phases, from seismic analysis, was ~ 25–30 m/s, and the velocity of the 16 May debris flood on the upper fan, from super-elevation and boulder sizes, was 5–10 m/s. The volume of debris deposited on the fan was ~ 104 m3, 2 orders of magnitude less than the avalanche/debris flow phases. Progressive glacier retreat and permafrost degradation were likely the conditioning factors; precursor rockfall activity was noted at least ~6 months previous; thus, the mountain was primed to fail. The 13 May landslide was apparently triggered by rapid snowmelt, with debuttressing triggering the 16 May event.

Unusual cause of airway obstruction after nasal intubation with a preformed endotracheal tube.

Unusual cause of airway obstruction after nasal intubation with a preformed endotracheal tube.

LeMar Outdoor Play Products, Ltd.: An Outsourcing Decision to India

This case, based on general business experience, casts students in the role of analyzing the financial effects of a possible outsourcing decision. Lee and Marcia Mills, owners of LeMar Outdoor Play Products, Ltd. (LOPP), a Canadian company that designs, manufactures, and installs outdoor play equipment, are faced with a decision pertaining to whether LOPP should outsource the company's back-office information technology enabled services (IT-ES) functions. Lee engages with an outside advisory firm specializing in matching companies with suitable outsourcing partners in India, and eventually a contract is presented. From just a financial perspective, students must ascertain whether Lee and Marcia should accept the outsourcing offer. Excerpt UVA-C-2440 Jun. 18, 2020 LeMar Outdoor Play Products, Ltd.: An Outsourcing Decision to India Even though their ages were beginning to show, Lee and Marcia Mills were young at heart. For the past 15 years, they had tirelessly worked to build their business, LeMar Outdoor Play Products, Ltd. (LOPP), into a western Canadian industry leader. Of late, their reputation for novel, safe, and well-built products had produced inquiries from potential new customers in the US East Coast and several family-oriented resorts in Latin America. The company designed, built, and installed all types of outdoor play equipment suitable for school-age children. Marcia was the whimsical, creative force behind the company's unique product designs. She was also in charge of the company's marketing, sales, and promotion activities, which were web-based, brochure-based, and via targeted direct mail. Lee, on the other hand, was the primary business manager—overseeing the production operations, product transport and installation, as well as back-office information technology-enabled services (IT-ES) such as accounting, website expansion/maintenance, and personnel payroll/benefits. Late one Sunday afternoon, during a rare moment while relaxing on one of their perpetual self-pushing swing sets, they had agreed on two things that set a number of wheels in motion. First, they agreed that they were both too busy—they were, as the saying goes, “burning the candle at both ends” at an unsustainable level. Second, they wanted to grow the business, taking on the new clients that were calling from more distant locations. Perhaps they would become the world's leader of outdoor play systems, or be presented with a buyout option too good to refuse from an established company already in the recreational equipment industry. Maybe a company like Nike or North Face might want to expand their product offerings and would be interested in acquiring LOPP's. The first of their shared realizations presented an immediate, follow-on task for Lee that he looked forward to addressing. He needed to find a business affiliate that could take on the company's back-office operations (e.g., accounting, employee benefits, and payroll administration) and promotional communications (both hardcopy and web-based), freeing him to focus on the production and installation aspects of the business. Regarding the promotions-related activity, Marcia would still create and design the promotions materials and strategies while the hoped-for outsourcing company would print all pertinent hardcopy brochures and execute all her web-based campaigns. Lee started his research the next morning. . . .

Atmospheric and emissivity corrections for ground-based thermography using 3D radiative transfer modelling

Methods to retrieve urban surface temperature (Ts) from remote sensing observations with sub-building scale resolution are developed using the Discrete Anisotropic Radiative Transfer (DART, Gastellu-Etchegorry et al., 2012) model. Corrections account for the emission and absorption of radiation by air between the surface and instrument (atmospheric correction), and for the reflected longwave infrared (LWIR) radiation from non-black-body surfaces (“emissivity” correction) within a single modelling framework. The atmospheric correction a) can use horizontally and vertically variable distributions of atmosphere properties at high resolution (<5 m); b) is applied here with vertically extrapolated weather observations and MODTRAN atmosphere profiles; and c) is a solution to ray tracing and cross section (e.g. absorption) conflicts (e.g. cross section needs the path length but it is typically unavailable during ray tracing). The emissivity correction resolves the reflection of LWIR radiation as a series of scattering events at high spatial (<1 m) and angular (ΔΩ ≈ 0.02 sr) resolution using a heterogeneous distribution of radiation leaving the urban surfaces. The method is applied to a novel network of seven ground-based cameras measuring LWIR radiation across a dense urban area (extent: 420 m × 420 m) where a detailed 3-dimensional representation of the surface and vegetation geometry is used. Our unique observation set allows the method to be tested over a range of realistic conditions as there are variations in: path lengths, view angles, brightness temperatures, atmospheric conditions and observed surface geometry. For pixels with 250 (±10) m path length the median (5th and 95th percentile) atmospheric correction magnitude is up to 4.5 (3.1 and 8.1) K at 10:10 on a mainly clear-sky day. The detailed surface geometry resolves camera pixel path lengths accurately, even with complex features such as sloped roofs.The atmospheric correction method evaluation, with simultaneous “near” (~15 m) and “far” (~155 m) observations, has a mean absolute error of 0.39 K. Using broadband approximations, the emissivity correction has clear diurnal variability, particularly when a cool and shaded surface (e.g. north facing) is irradiated by warmer (up to 17.0 K) surfaces (e.g. south facing). Varying the material emissivity with bulk values common for dark building materials (ε = 0.89 → 0.97) alters the corrected roof (south facing) surface temperatures by ~3 (1.5) K, and the corrected cooler north facing surfaces by less than 0.1 K. Corrected observations, assuming a homogeneous radiation distribution from surfaces (analogous to a sky view factor correction), differ from a heterogeneous distribution by up to 0.25 K. Our proposed correction provides more accurate Ts observations with improved uncertainty estimates. Potential applications include ground-truthing airborne or space-borne surface temperatures and evaluation of urban energy balance models.

Economic model predictive control of space heating and dynamic solar shading

Dynamic solar shading devices are an effective mean to avoid overheating in buildings due to excessive solar heat gains. They can also be used to affect the heat balance of buildings; they can be on e.g. during nighttime to reduce space heating or retracted to increase night cooling. The shading control system can utilize this feature to obtain energy cost savings and reduce peak consumption. However, it is difficult to define optimal rule-based control strategies that minimize overheating and energy costs simultaneously. In this paper, we therefore propose an economic model predictive control (E-MPC) scheme for space heating where solar shading is included as an additional control variable. The proposed scheme employs black-box models, as they are ‘cheap’ to create from data; this is important for a widespread deployment of E-MPC in practice. The study was based on co-simulation experiments where EnergyPlus models represented the actual building and it was hereby demonstrated that the proposed E-MPC outperformed two rule-based controllers with respect to reducing overheating, energy costs and peak consumption. Shading also turned out to be valuable for north facing rooms where it reduced costs and peak consumptions compared to an MPC without shading. The energy-related benefits of the proposed E-MPC scheme can be regarded as ‘an added value’ that can be used for economic justification of an investment in dynamic solar shading devices.

A Booming City in the Far North

Many cities of Russia’s Far North face a massive population decline, with the exception of those based on oil and gas extraction in the Yamalo-Nenets Autonomous District. Yet, there is one more exception to that trend: the city of Yakutsk, capital of the Sakha (Yakutia) Republic, whose population is booming, having grown from 186,000 in 1989 to 338,000 in 2018, This unique demographic dynamism is founded on the massive exodus of the ethnic Yakut population from rural parts of the republic to the capital city, a process that has reshaped the urban cultural landscape, making Yakutsk a genuine indigenous regional capital, the only one of its kind in the Russian Far North.

Environmental variables vis-a-vis distribution of herbaceous tracheophytes on northern sub-slopes in Western Himalayan ecotone

BackgroundIn the northern hemisphere, the north face of the mountains has a high diversity of species which is attributed to the moist and shady conditions at the north face. Other environmental variables may also influence the species diversity on the northern faces of the mountain and therefore needs to be studied in detail. The northern slopes represent three different sub-slopes—north, north east, and north west. During the current investigation of Pir-Panjal and Dauladhar ranges in Bhadarwah valley, fine-scale studies on the relationship between vegetation and four variables (soil pH, moisture content, electrical conductivity, and steepness) were conducted. The study determined the role of these variables on the vegetation of three different sub-slopes. The sampling was done at the confluence of two communities (forest and grassland) at three sites on the northern sub-slopes of the lesser stratum in western Himalayan.ResultsThe result revealed that rich herbaceous diversity prevails on the lesser Himalayan stratum (Bhadarwah valley). As many as 65.8% species differ from site to site, whereas species commonality among the sites is minimum. The role of environmental variables on the species composition at different sub-slopes of the north mountain face is deduced through canonical correspondence analysis (CCA).ConclusionsThe availability of solar light increases air and soil temperature on the north east–facing slope. All the environmental variables (soil pH, moisture, electrical conductivity, and mountain steepness) are insignificant at pure north face for the species composition. Therefore, it can be concluded that some other environmental variables may influence the species composition which are needed to be further investigated.

Habitat fragmentation and anthropogenic factors affect wildcat Felis silvestris silvestris occupancy and detectability on Mt Etna

Knowledge of patterns of occupancy is crucial for planning sound biological management and for identifying areas which require paramount conservation attention. The European wildcat Felis silvestris is an elusive carnivore and is classified as ‘least concern' on the IUCN red list, but with a decreasing population trend in some areas. Sicily hosts a peculiar wildcat population, which deserves conservation and management actions, due to its isolation from the mainland. Patterns of occupancy for wildcats are unknown in Italy, and especially in Sicily. We aimed to identify which ecological drivers determined wildcat occurrence on Mt Etna and to provide conservation actions to promote the wildcats’ long-term survival in this peculiar environment. The genetic identity of the wildcat population was confirmed through a scat-collection which detected 22 different wildcat individuals. We analysed wildcat detections collected by 91 cameras using an occupancy frame work to assess which covariates influenced the detection (p) and the occupancy (ψ) estimates. We recorded 70 detections of the target species from 38 cameras within 3377 trap-days. Wildcat detection was positively influenced by the distance to the major paved roads and negatively affected by the presence of humans. Wildcat occupancy was positively associated with mixed forest and negatively influenced by pine forest, fragmentation of mixed forest and altitude. A spatially explicit predicted occupancy map, validated using an independent dataset of wildcat presence records, showed that higher occupancy estimates were scattered, mainly located on the north face and at lower altitude. Habitat fragmentation has been claimed as a significant threat for the wildcat and this is the first study that has ascertained this as a limiting factor for wildcat occurrence. Conservation actions should promote interconnectivity between areas with high predicted wildcat occupancy while minimising the loss of habitat.

P312The acute impact of a high altitude ultra-trail race on the ECG

Abstract Background Ultra-endurance competitions are becoming increasingly popular but the consequences of ultra-endurance sports activity on the heart rhythm is still a debated issue. Some authors demonstrated that athletes engaging in ultra-endurance sports show a transient rise in cardiac biomarkers and right ventricular dysfunction after a competition, suggesting the possibility of an adverse arrhythmic remodeling and an increased risk of sudden cardiac death. The aim of our study was to evaluate the effects on heart rhythm of an ultraendurance high-altitude race. Methods The study was performed during the 2018 North Face® Lavaredo Ultra Trail mountain run. We recorded the ECG with the FDA-approved MyDiagnostick device. Recordings were performed at baseline the day before the run and immediately after the run in the available athletes. The ECG was analyzed for heart rate, QRS duration, QT interval duration corrected according to the Bazett formula and presence of at least one beat of presumed ventricular origin (PVB). Results A total of 545 athletes (83% males, mean age: 40±9 years), 241 running the 120 Km race and 304 running the 50 Km race, were included in the study. At baseline, athletes showed a mean heart rate of 64±14 bpm and a mean QRS duration of 92±18 ms. Three (0.5%) showed at least one PVB. Analysis of QTc interval duration showed a mean value of 412±25 ms. After the race, athletes showed a higher heart rate (91±13 bpm, p&amp;lt;0.001), a similar QRS duration (94±16 ms, p=0.32) and a longer QTc interval duration (447±25 ms, p&amp;lt;0.001), as compared to baseline data. The number of athletes showing at least 1 PVB significantly increased to 18 (3.3%, p=0.004) as compared to pre-race evaluation. Athletes engaged in the 120 Km run showed a slightly longer post-run QTc interval (450±24 versus 444±25 ms, p=0.009) while the post-run QRS duration was similar between the two groups. The presence of PVBs after the race was not correlated with the duration of QTc interval. Conclusions In this study we found an increased number of PVBs and a prolonged QTc duration after an ultra-endurance competition. Increased ventricular ectopic activity and QT prolongation recorded shortly after an intense and prolonged exercise could contribute to the increased risk of arrhythmias occurring after the finish line.

Controlling factors of plant community composition with respect to the slope aspect gradient in the Qilian Mountains

AbstractSlope aspect can affect soil temperature and soil type distribution, which, in turn, is likely to influence plant community composition. Three Qilian mountains, located in the northeastern part of the Qinghai–Tibetan Plateau, China, with four distinct slope aspects including south‐facing (SF), southwest‐facing (SW), northwest‐facing (NW), and north‐facing (NF) slope aspects, were studied to investigate the impact of slope aspect on plant assemblages. The results indicated that the environmental conditions were favorable under the NF and NW slope aspects as the soil water, soil organic carbon (SOC), and soil total nitrogen (STN) contents were significantly higher, and soil temperature (ST) and soil bulk density (SBD) were significantly lower than under the SF and SW aspects. Under all slope aspects, however, SOC, STN, and soil total phosphate in the top 0.2 m of topsoil accounted for about 60% of its total quantity, to a soil depth of 0.6 m. The plant communities on the SF and SW slopes were found to be primarily composed of Poa pratensis, Potentilla anrisena, and Carex aridula. In contrast, the plant community on the NW slope was mainly composed of Kobresia humilis, Carex crebra, and Potentilla bifurca, while on the NF slope it was mainly composed of Picea crassifolia, Carex scabrirostris, and Polygonum macrophyllum. The order of the influence of environmental factors on species distributions was ST &gt; SBD &gt; sand &gt; STN. Results suggest that the slope aspect has an important role in the regulation of the soil environment and plant assemblages and that ST and SBD were the main factors influencing plant community composition. Furthermore, evidence from this study suggests that these mountains will become increasingly vulnerable to global warming. Thus, the plant community composition on these mountains must be monitored continuously in order to allow for strategic adaptive management.