A Preliminary Evaluation of the Millennial Shopping Experience: Preferences and Plateaus

This study identified and examined the concerns of hotel general managers regarding ethics in the hospitality industry. Thirty-five managers were interviewed during and immediately following the economic recession to determine which ethical issues in the hotel industry and at their own properties concerned them the most. Results showed that more people and organizations attempted to renegotiate hotel rates, which actions, in turn, led to some lapses in ethical behavior. Managers said that because of the economic downturn, they felt pressure from both private owners and corporate headquarters. They also said a lack of work ethic, low motivation, and low pay caused many workers to underperform in ways that raised ethical issues. Managers also mentioned diversity issues and theft by both guests and employees as ethical issues of concern, and shared stories about their experiences

Visual estimation of ACL injury risk: Efficient assessment method, group differences, and expertise mechanisms

Simple observational assessment of movement quality (e.g., drop vertical jump biomechanics) is an efficient and low cost method for anterior cruciate ligament (ACL) injury screening and prevention. A recently developed test (see www.ACL-IQ.org) has revealed substantial cross-professional/group differences in visual ACL injury risk estimation skill. Specifically, parents, sport coaches, and to some degree sports medicine physicians, would likely benefit from training or the use of decision support tools. In addition, expertise mechanisms (perceptual-cognitive characteristics of skilled performers) were investigated in order to design training systems to improve risk estimation performance

Post-Exercise Arterial Stiffness Responses Are Similar After Acute Eccentric and Concentric Arm Cycling

Upper-body resistance exercise effectively increases muscular strength, but may concomitantly increase arterial stiffness. Eccentric exercise can lead to muscle soreness and arterial stiffness in untrained participants. However, it is unclear if upper-body eccentric exercise could reduce arterial stiffness in a single session for participants that have undergone progressive training. Our purpose was to compare acute responses to upper-body eccentric (novel, ECCarm) and concentric (traditional, CONarm) steady state arm cycling. We hypothesized that arm arterial stiffness would be reduced after both ECCarm and CONarm. Twenty-two young healthy individuals performed either ECCarm ( = 11) or CONarm ( = 11) at ~70% of peak heart rate for 20 min after a training period. Heart rate, central pulse wave velocity (cPWV), and peripheral pulse wave velocity (pPWV; i.e., arm arterial stiffness) were assessed before, 10 min, and 30 min after exercise. Heart rate was not elevated at 10 min post ECCarm, but was elevated at 10- and 30-min post CONarm ( \u3c 0.01). After exercise, pPWV was decreased at 10 min post for both ECCarm (7.1 ± 0.3 vs. 6.5 ± 0.2 m/s) and CONarm (7.0 ± 0.2 vs. 6.5 ± 0.2 m/s; \u3c 0.05), while both groups returned to baseline values 30 min post. cPWV did not change in either group. Our results indicate that acute ECCarm provides a high-force, low energy cost form of resistance exercise that acutely reduces arm arterial stiffness. The reduction in pPWV and rapid heart rate recovery suggests that ECCarm is a safe form of exercise for overall and cardiovascular health

The relationship of high-intensity cross-training with arterial stiffness

Background Central arterial stiffness is a cardiovascular risk factor that can be readily affected through engagement in physical exercise training, with resistance and aerobic exercise having disparate affects. Despite the growing popularity of high-intensity cross-training (HICT), little is currently known about the effects of this mixed modality exercise stimulus on arterial stiffness. Therefore, the purpose of this study was to characterize the arterial stiffness of habitual HICT participants vs. aerobically active and sedentary controls using a cross-sectional design. Methods A total of 30 participants were recruited: 10 middle-aged long-term participants of HICT (CrossFit) and 20 age, sex, and height matched controls (10 recreationally active, 10 sedentary). Central and peripheral pulse wave velocities were measured for the carotid-femoral and femoral-dorsalis pedis arterial segments. Aerobic fitness (maximal oxygen uptake, VO2max) was measured and typical exercise participation rates were self-reported for each group. Results HICT participants manifested central pulse wave velocity (PWV) (5.3 ± 1.0 m/s, mean ± SD) and VO2max (43 ± 6 mL/kg/min) values nearly identical to active controls. Both active groups had significantly better values than sedentary controls (7.1 ± 1.0 m/s, p ≤ 0.001; and 32 ± 7 mL/kg/min, p = 0.01). No differences were observed in peripheral PWV between groups. Conclusion Habitual participation in HICT exercise was not associated with increased central nor peripheral arterial stiffness. Long-term HICT participants presented with similar fitness and arterial stiffness as compared with participants who practiced traditional aerobic exercise. Compared to sedentary living, HICT may offer musculoskeletal and cardiovascular health benefits without negatively impacting arterial stiffness

Modelling ecosystem adaptation and dangerous rates of global warming

This is the author accepted manuscript. The final version is available from Portland Press via the DOI in this recordWe are in a period of relatively rapid climate change. This poses challenges for individual species and threatens the ecosystem services that humanity relies upon. Temperature is a key stressor. In a warming climate, individual organisms may be able to shift their thermal optima through phenotypic plasticity. However, such plasticity is unlikely to be sufficient over the coming centuries. Resilience to warming will also depend on how fast the distribution of traits that define a species can adapt through other methods, in particular through redistribution of the abundance of variants within the population and through genetic evolution. In this paper, we use a simple theoretical ‘trait diffusion’ model to explore how the resilience of a given species to climate change depends on the initial trait diversity (biodiversity), the trait diffusion rate (mutation rate), and the lifetime of the organism. We estimate theoretical dangerous rates of continuous global warming that would exceed the ability of a species to adapt through trait diffusion, and therefore lead to a collapse in the overall productivity of the species. As the rate of adaptation through intraspecies competition and genetic evolution decreases with species lifetime, we find critical rates of change that also depend fundamentally on lifetime. Dangerous rates of warming vary from 1°C per lifetime (at low trait diffusion rate) to 8°C per lifetime (at high trait diffusion rate). We conclude that rapid climate change is liable to favour short-lived organisms (e.g. microbes) rather than longer-lived organisms (e.g. trees).University of ExeterCSSP-Brazi

Dynamic Range Majority Data Structures

Given a set $P$ of coloured points on the real line, we study the problem of answering range $\alpha$-majority (or "heavy hitter") queries on $P$. More specifically, for a query range $Q$, we want to return each colour that is assigned to more than an $\alpha$-fraction of the points contained in $Q$. We present a new data structure for answering range $\alpha$-majority queries on a dynamic set of points, where $\alpha \in (0,1)$. Our data structure uses O(n) space, supports queries in $O((\lg n) / \alpha)$ time, and updates in $O((\lg n) / \alpha)$ amortized time. If the coordinates of the points are integers, then the query time can be improved to $O(\lg n / (\alpha \lg \lg n) + (\lg(1/\alpha))/\alpha))$. For constant values of $\alpha$, this improved query time matches an existing lower bound, for any data structure with polylogarithmic update time. We also generalize our data structure to handle sets of points in d-dimensions, for $d \ge 2$, as well as dynamic arrays, in which each entry is a colour.Comment: 16 pages, Preliminary version appeared in ISAAC 201

The Complexity of Drawing Graphs on Few Lines and Few Planes

It is well known that any graph admits a crossing-free straight-line drawing in $\mathbb{R}^3$ and that any planar graph admits the same even in $\mathbb{R}^2$. For a graph $G$ and $d \in \{2,3\}$, let $\rho^1_d(G)$ denote the minimum number of lines in $\mathbb{R}^d$ that together can cover all edges of a drawing of $G$. For $d=2$, $G$ must be planar. We investigate the complexity of computing these parameters and obtain the following hardness and algorithmic results. - For $d\in\{2,3\}$, we prove that deciding whether $\rho^1_d(G)\le k$ for a given graph $G$ and integer $k$ is ${\exists\mathbb{R}}$-complete. - Since $\mathrm{NP}\subseteq{\exists\mathbb{R}}$, deciding $\rho^1_d(G)\le k$ is NP-hard for $d\in\{2,3\}$. On the positive side, we show that the problem is fixed-parameter tractable with respect to $k$. - Since ${\exists\mathbb{R}}\subseteq\mathrm{PSPACE}$, both $\rho^1_2(G)$ and $\rho^1_3(G)$ are computable in polynomial space. On the negative side, we show that drawings that are optimal with respect to $\rho^1_2$ or $\rho^1_3$ sometimes require irrational coordinates. - Let $\rho^2_3(G)$ be the minimum number of planes in $\mathbb{R}^3$ needed to cover a straight-line drawing of a graph $G$. We prove that deciding whether $\rho^2_3(G)\le k$ is NP-hard for any fixed $k \ge 2$. Hence, the problem is not fixed-parameter tractable with respect to $k$ unless $\mathrm{P}=\mathrm{NP}$

THE EFFECT OF REACHING TO AN OVERHEAD GOAL WHILE PERFORMING THE COUNTERMOVEMENT JUMP

One potentially simple way to maximize jumping effort and thus intensity is to have athletes jump to and attempt to touch challenging overhead goals during training. The purpose of this study was to compare the effect of jumping with and without the use of an overhead goal. Subjects performed 3 countermovement jumps in conditions with and without an overhead goal. Jump performance was evaluated using a force platform to determine peak ground reaction force, time to takeoff, power, and jump height. Data were evaluated with a two way ANOVA with results demonstrating no significant (p > 0.05) difference between goal conditions for any of the variables assessed and no interaction between goal condition and gender (p > 0.05)