A study of the probability of depositing viable organisms on Mars during the Mariner 1964 mission

Probability of depositing viable organisms on Mars during 1964 Mariner missio

Visual complexity, player experience, performance and physical exertion in motion-based games for older adults

Motion-based video games can have a variety of benefits for the players and are increasingly applied in physical therapy, rehabilitation and prevention for older adults. However, little is known about how this audience experiences playing such games, how the player experience affects the way older adults interact with motion-based games, and how this can relate to therapy goals. In our work, we decompose the player experience of older adults engaging with motion-based games, focusing on the effects of manipulations of the game representation through the visual channel (visual complexity), since it is the primary interaction modality of most games and since vision impairments are common amongst older adults. We examine the effects of different levels of visual complexity on player experience, performance, and exertion in a study with fifteen participants. Our results show that visual complexity affects the way games are perceived in two ways: First, while older adults do have preferences in terms of visual complexity of video games, notable effects were only measurable following drastic variations. Second, perceived exertion shifts depending on the degree of visual complexity. These findings can help inform the design of motion-based games for therapy and rehabilitation for older adults

A community pharmacy weight management programme: an evaluation of effectiveness

<p>Background: Community pharmacies may offer an accessible way of delivering weight-management programmes but there have been few trials that use clinically significant weight loss outcomes, objective measures of weight and follow-up to 12 months. We aimed to evaluate weight change among patients who used the Counterweight weight management programme delivered by community pharmacies.</p> <p>Methods: The Counterweight Programme was introduced into community pharmacies in Fife, Scotland in 2009 for patients with a BMI ≥ 30 kg/m2 or a BMI ≥ 28 kg/m2 with a co-morbidity in localities in which Counterweight was not available at GP practices. The aim was to achieve an energy deficit of 500-600 kcal per day. Counterweight specialist dietitians delivered training, support and patient information materials to community pharmacies. Patient weight was measured by pharmacy staff at each weight management session. Weight data recorded at each weight management session were used to estimate weight change and attendance at 3, 6 and 12 months.</p> <p>Results: Between March 2009 and July 2012, 458 patients were enrolled by the community pharmacies. Three-quarters of patients were women, mean age was 54 (SD 7.4) years and mean BMI 36.1 (SD 5.9) kg/m2. Of 314 patients enrolled for at least 12 months, 32 (10.2% on an intention to treat basis) had achieved the target weight loss of ≥5%; this was 41.6% of those who attended at 12 months representing a mean weight loss of 4.1 kg. Using Last Observation Carried Forward, 15.9% achieved the target weight loss within 12 months of enrolling. There was no significant effect of sex, baseline BMI or age on weight loss.</p> <p>Conclusions: The Counterweight pharmacy programme has a similar effectiveness to other primary care based weight management programmes and should be considered as part of a range of services available to a community to manage overweight and obesity.</p&gt

Bose-Einstein transition temperature in a dilute repulsive gas

We discuss certain specific features of the calculation of the critical temperature of a dilute repulsive Bose gas. Interactions modify the critical temperature in two different ways. First, for gases in traps, temperature shifts are introduced by a change of the density profile, arising itself from a modification of the equation of state of the gas (reduced compressibility); these shifts can be calculated simply within mean field theory. Second, even in the absence of a trapping potential (homogeneous gas in a box), temperature shifts are introduced by the interactions; they arise from the correlations introduced in the gas, and thus lie inherently beyond mean field theory - in fact, their evaluation requires more elaborate, non-perturbative, calculations. One illustration of this non-perturbative character is provided by the solution of self-consistent equations, which relate together non-linearly the various energy shifts of the single particle levels k. These equations predict that repulsive interactions shift the critical temperature (at constant density) by an amount which is positive, and simply proportional to the scattering length a; nevertheless, the numerical coefficient is difficult to compute. Physically, the increase of the temperature can be interpreted in terms of the reduced density fluctuations introduced by the repulsive interactions, which facilitate the propagation of large exchange cycles across the sample.Comment: two minor corrections, two refs adde

Cluster analysis of midlatitude oceanic cloud regimes: mean properties and temperature sensitivity

Clouds play an important role in the climate system by reducing the amount of shortwave radiation reaching the surface and the amount of longwave radiation escaping to space. Accurate simulation of clouds in computer models remains elusive, however, pointing to a lack of understanding of the connection between large-scale dynamics and cloud properties. This study uses a k-means clustering algorithm to group 21 years of satellite cloud data over midlatitude oceans into seven clusters, and demonstrates that the cloud clusters are associated with distinct large-scale dynamical conditions. Three clusters correspond to low-level cloud regimes with different cloud fraction and cumuliform or stratiform characteristics, but all occur under large-scale descent and a relatively dry free troposphere. Three clusters correspond to vertically extensive cloud regimes with tops in the middle or upper troposphere, and they differ according to the strength of large-scale ascent and enhancement of tropospheric temperature and humidity. The final cluster is associated with a lower troposphere that is dry and an upper troposphere that is moist and experiencing weak ascent and horizontal moist advection. <br><br> Since the present balance of reflection of shortwave and absorption of longwave radiation by clouds could change as the atmosphere warms from increasing anthropogenic greenhouse gases, we must also better understand how increasing temperature modifies cloud and radiative properties. We therefore undertake an observational analysis of how midlatitude oceanic clouds change with temperature when dynamical processes are held constant (i.e., partial derivative with respect to temperature). For each of the seven cloud regimes, we examine the difference in cloud and radiative properties between warm and cold subsets. To avoid misinterpreting a cloud response to large-scale dynamical forcing as a cloud response to temperature, we require horizontal and vertical temperature advection in the warm and cold subsets to have near-median values in three layers of the troposphere. Across all of the seven clusters, we find that cloud fraction is smaller and cloud optical thickness is mostly larger for the warm subset. Cloud-top pressure is higher for the three low-level cloud regimes and lower for the cirrus regime. The net upwelling radiation flux at the top of the atmosphere is larger for the warm subset in every cluster except cirrus, and larger when averaged over all clusters. This implies that the direct response of midlatitude oceanic clouds to increasing temperature acts as a negative feedback on the climate system. Note that the cloud response to atmospheric dynamical changes produced by global warming, which we do not consider in this study, may differ, and the total cloud feedback may be positive

China as a “National Strategic Buyer”: Towards a Multilateral Regime for Cross-Border M&A

Unlike the case of cross-border trade, there is no explicit international governance regime for cross-border M&A; rather, there is a shared understanding that publicly traded companies are generally for purchase by any bidder—domestic or foreign—willing to offer a sufficiently large premium over a target’s stock market price. The unspoken premise that undergirds the system is that the prospective buyer is motivated by private economic gain-seeking. The entry of China into the global M&A market threatens the fundamental assumptions of the current permissive international regime. China has become a significant player in the cross-border M&A market, particularly as an acquirer. The central claim of the article is that the cross-border M&A regime will require a new rules-of-the-game structure to take account of China’s ascension. This is because cross-border M&A with China introduces a new dimension: what we call the “national strategic buyer” (“NSB”), whose objective is to further the interests of a nation-state in the pursuit of industrial policy or out of national security concerns. Thus, China presents a problem of asymmetric motives in the global M&A market: sellers to Chinese firms have private motives for pursuing transactions, while at least some Chinese acquirers have non-economic motivations. Yet distinguishing commercial and financial motives from national strategic motives in Chinese firms is difficult. To date, the only mechanisms for addressing the NSB problem are national security review mechanisms such as the CFIUS process in the United States, as recently expanded through legislative amendment. The EU is moving forward on a screening regulation with a similar objective that contemplates activity both by the European Commission and the Member States. Whether suitably tailored or not, these approaches fail to take on the long-term concern of fully assimilating China as a normal actor in the global economic system. To address the NSB problem, we propose the adoption of a multilateral regime under which firms subject to potential government influence in their corporate decision-making must demonstrate their “eligibility” to engage in outbound M&A. For covered firms, the regime would require a commitment to exclusively commercial/financial motives in cross-border acquisitions, made credible through a corporate governance set-up featuring independent directors (selected by foreign investors) who publicly verify adherence and disclose the source of acquisition financing. Enforcement would consist of a secretariat that can evaluate eligibility and monitor post-acquisition conduct, and national legislation that would permit rejection of an acquisition of a local target by an acquirer that does not meet the eligibility criteria