Urban Parks: Volunteers and Civic Engagement

2 pp., 7 photosWhen citizens are engaged with urban park and recreation departments, everyone benefits. This publication describes successful programs that involve community volunteers, and explains what managers can do to engage citizens in such programs

Information vs Competition:How Platform Design Affects Profits and Surplus

We study the design of online platforms that aggregate information and facilitate transactions. Two different designs can be observed in the market: revealing platforms that disclose the identity of transaction partners(e.g.Booking) and anonymous platforms that do not (e.g. Hotwire).To analyse the implications of this design choice for profit sand surplus, we develop a model in which consumers differ in their location as well as their preferred productvariety. Sellers offer their products for sale both directly(`offine') and indirectly via the platform(`online') but are unable to credibly disclose the productvariety they offer when selling online. The model gives rise to a novel trade-off associated with the anonymous platform design: offline, consumers observe location but not variety; online, they observe variety but not location. While there vealing design leads to more informed consumers and better matches, the anonymous design allows sellers top rice discriminate and introduces competition between sellers whose markets would otherwise be segmented. We show that the comparison between the designs depends crucially on the relative importance of information about location vis-a-vis information about variety. For an intermediate range, the anonymous design outperforms there vealing design in terms of both profits and welfare

Magnetoresistance in two-component systems

Two-component systems with equal concentrations of electrons and holes exhibit non-saturating, linear magnetoresistance in classically strong magnetic fields. The effect is predicted to occur in finite-size samples at charge neutrality in both disorder- and interaction-dominated regimes. The phenomenon originates in the excess quasiparticle density developing near the edges of the sample due to the compensated Hall effect. The size of the boundary region is of the order of the electron-hole recombination length that is inversely proportional to the magnetic field. In narrow samples and at strong enough magnetic fields, the boundary region dominates over the bulk leading to linear magnetoresistance. Our results are relevant for semimetals and narrow-band semiconductors including most of the topological insulators.Comment: 11 pages, 3 figure

Environmental transmission of a personality trait: foster parent exploration behaviour predicts offspring exploration behaviour in zebra finches

Consistent behavioural differences among individuals are common in many species and can have important effects on offspring fitness. To understand such ‘personality’ variation, it is important to determine the mode ofinheritance, but this has been quantified for only a few species. Here, we report results from a breeding experiment in captive zebra finches, Taeniopygia guttata, in which we cross-fostered offspring to disentangle the importance of genetic and nongenetic transmission of behaviour. Genetic and foster-parents’ exploratory type was measured in a novel environment pre-breeding and offspring exploratory type was assessed at adulthood. Offspring exploratory type was predicted by the exploratory behaviour of the foster but not the genetic parents, whereas offspring sizewas predicted by genetic but not foster-parents’ size. Other aspects of the social environment, such as rearing regime (uni- versus biparental), hatching position, brood size or an individual’s sex did not influence offspring exploration. Our results therefore indicate that non-genetic transmission of behaviour can play an important role in shaping animal personality variation

Initial Stages of Sodium Deposition onto Au(111) from [MPPip][TFSI]: An In‐Situ STM Study for Sodium‐Ion Battery Electrolytes

Sodium-ion batteries are promising candidates for post-lithium-ion batteries. While sodium has a less negative standard electrode potential compared to lithium, it is still a strong reducing agent. Ionic liquids are suitable solvents for sodium metal batteries, since metallic sodium is very reactive, particularly with water and molecules containing acidic hydrogen atoms. In this study, the initial stages of electrodeposition of sodium on Au(111) from N-methyl-N-propylpiperidinium [MPPip] bis(trifluoromethanesulfonyl)imide [TFSI] were studied using voltammetry and in-situ scanning tunnelling microscopy. Four subsequent underpotential deposition stages were observed: (i) nucleation at the Au(111) reconstruction elbows, followed by (ii) growth of small monoatomically high islands that form (iii) a smooth layer via coalescence, and (iv) further island growth on top of the existing layers. The electrocrystallisation mode changed from smooth layer formation to 3D growth, resulting in cauliflower-like structures. The deposition process was accompanied by simultaneous alloy formation

National Park Service Visitation and Interest: An Update Through 2009

Abstract The purpose of this paper was to examine and refute suggestions in the literature that national park visitation is on the decline. Data from a large annual national syndicated secondary dataset were examined for 2000-2009. In addition, data from Google Insights™ related to internet searches about national park vacation travel were also used as a proxy measure to determine if interest in outdoor recreation visitation to national parks had declined. While there was evidence of some decline in visitation to national parks from 2000-2009, most of the decline occurred from 2000-2004 and there was a rebound in interest from 2004 through 2009 with the exception of a dip in 2008. Data from internet search engine queries about national parks also provided insights into visitation interest. There was some decline in interest in visiting national parks for vacation travel based on search engine inquiries; however, this decline has been cyclical and is not dramatic

Digital Orthopaedics: A Glimpse Into the Future in the Midst of a Pandemic.

BackgroundThe response to COVID-19 catalyzed the adoption and integration of digital health tools into the health care delivery model for musculoskeletal patients. The change, suspension, or relaxation of Medicare and federal guidelines enabled the rapid implementation of these technologies. The expansion of payment models for virtual care facilitated its rapid adoption. The authors aim to provide several examples of digital health solutions utilized to manage orthopedic patients during the pandemic and discuss what features of these technologies are likely to continue to provide value to patients and clinicians following its resolution.ConclusionThe widespread adoption of new technologies enabling providers to care for patients remotely has the potential to permanently change the expectations of all stakeholders about the way care is provided in orthopedics. The new era of Digital Orthopaedics will see a gradual and nondisruptive integration of technologies that support the patient's journey through the successful management of their musculoskeletal disease