The coevolution of costly heterogeneities and cooperation in the prisoner's dilemma game

This paper discusses the co-evolution of social strategies and an efficiency trait in spatial evolutionary games. The continuous efficiency trait determines how well a player can convert gains from a prisoner's dilemma game into evolutionary fitness. It is assumed to come at a cost proportional to its magnitude and this cost is deducted from payoff. We demonstrate that cost ranges exist such that the regime in which cooperation can persist is strongly extended by the co-evolution of efficiencies and strategies. We find that cooperation typically associates with large efficiencies while defection tends to pair with lower efficiencies. The simulations highlight that social dilemma situations in structured populations can be resolved in a natural way: the nature of the dilemma itself leads to differential pressures for efficiency improvement in cooperator and defector populations. Cooperators benefit by larger improvements which allow them to survive even in the face of inferior performance in the social dilemma. Importantly, the mechanism is possible with and without the presence of noise in the evolutionary replication process

AN ITERATIVE INTERLACING APPROACH FOR SYNTHESIS OF COMPUTER-GENERATED HOLOGRAMS

A new approach to optimizing computer-generated holograms (CGH\u27s) is discussed. The approach can be summarized most generally as hierarchically designing a number of holograms to add up coherently to a single desired reconstruction. In the case of binary holograms, this approach results in the interlacing (IT) and the iterative interlacing (IIT) techniques. In the IT technique, a number of subholograms are designed and interlaced together to generate the total binary hologram. The first sttbhologram is designed to reconstruct the desired image. The succeeding subholograms are designed to correct the remaining error image. In the IIT technique, the remaining error image after the last subhologram is circulated back to the first subhologram, and the process is continued a number of sweeps until convergence. The IT and the IIT techniques can be used together with most CGH synthesis algorithms, and result in substantial reduction in reconstruction error as well as increased speed of convergence in the case of iterative algorithms

Barriers and facilitators to providing CBT for people living with dementia: perceptions of psychological therapists

Many people living with dementia or mild cognitive impairment (MCI) experience anxiety and depression. Cognitive behavioral therapy (CBT) is a recommended treatment for adults, commonly provided through primary care psychological therapies services. This study explored the facilitators and barriers to providing CBT interventions for people living with dementia or MCI, as perceived by therapists working in such services. Structured interviews were conducted with fourteen clinicians recruited through primary care psychological therapies services about their experiences of working with people living with dementia or MCI and their ideas about factors that enhance or hinder offering and delivering CBT to this population. Interview recordings were transcribed and analyzed using Thematic Analysis. Credibility checks were incorporated throughout. Three themes were identified: 'attitudes towards dementia', 'competing demands', and 'pressure without support'. Perceived facilitators and barriers occurred across individual, service, and system levels. Facilitators were: positive engagement and outcomes for people living with dementia or MCI, positive attitudes of clinicians, and flexibility within some services. In contrast, perceived barriers were: stigma towards dementia and mental health in older adults, high pressure on staff to perform with a lack of support to do so, exclusion based on diagnosis, and inflexibility within some services. Clinicians were confident that people living with dementia or MCI could benefit from CBT, with some adaptations to delivery. There are implications for staff support and training, and for commissioning practices relating to the tension between minimal resources, equitable access, and person-centered care

Escherichia coli serotypes associated with urinary tract infections in the Western Cape

CITATION: Brede, H. D., et al. 1974. Escherichia coli serotypes associated with urinary tract infections in the Western Cape. South African Medical Journal, 48(7):261-263.The original publication is available at http://www.samj.org.zaExamination of 3,261 specimens of urine from patients with urinary tract infections led to the isolation of E. coli types from 933 samples (28.6%). Serological typing revealed 222 isolates (23.8%) as urinary or as enteropathogenic serotypes. The rest were untypable. The following urinary types were identified: O 1, O 2, O 4, O 5, O 6, O 7, O 9, O 11, O 18, O 39, O 75, the commonest being O 6, O 4, and O 75. Enteropathogenic types were O 26-B6, O 55-B5, O 86-B7, O 111-B4, O 112-B11, O 119-B14, O 124-B17, O 125-B15, O 126-B16, O 127-B8, O 128-B12, and O 142-B. Types O 112 and O 111 were the most prevalent. The 1973 pattern of urinary E. coli infections in the Western Cape differs from that found in other parts of the world. Type O 6 is most prevalent, followed by O 4, and O 75. The last is the most common type north of the equator. Other types were far less frequent. Crossreactivity between 14 V. cholerae strains and E. coli O 39 antiserum was proved, suggesting similarities between the enterotoxins of V. cholerae and pathogenic E. coli strains.Publisher’s versio

Green Up-Conversion Laser-Emission In Er-Doped Crystals At Room-Temperature

We report room-temperature pulsed up-conversion laser oscillation in Er-doped LiYF4 and KYF4 at 551 and 562 nm, respectively. In both crystals laser oscillation is observed on the S-4(3/2)-I-4(15/2) ground state transition. Excitation was provided by a tunable flashlamp-pumped Ti:sapphire laser in the spectral region around 810 nm. Additional pumping with a continuous wave krypton ion laser at 647 nm was beneficial to both lasers. Laser action has also been observed in Er-doped Y3Al5O12 on the same transition

Behavioural activation for depression in older people: systematic review and meta-analysis

BACKGROUND: Behavioural activation is an effective treatment for depression in the general adult population but it is unclear whether it is effective for older people. AIMS: To systematically review randomised controlled trials (RCTs) of behavioural activation for depression in older people. METHOD: We searched Medline, EMBASE, PsycINFO, CINAHL and online trial registers for RCTs of behavioural activation for depression in older people. RESULTS: Eighteen trials were included in the meta-analyses. Behavioural activation reduced mean depression scores for older people living in the community as a stand-alone treatment: standardised mean difference (SMD) -0.72, 95% CI -1.04 to -0.41. It was also effective as part of a multicomponent intervention (SMD -0.44, 95% CI -0.56 to -0.32). CONCLUSIONS: Behavioural activation significantly reduces depressive symptoms in older people in the community; however, given that most studies are small and with significant bias results should be interpreted with caution. Further high-quality trials of behavioural activation for this age group are needed

Spectroscopy And Green Up-Conversion Laser-Emission Of Er(3+)-Doped Crystals At Room-Temperature

The spectroscopic parameters of Er3+-doped crystals were determined with regard to the upconversion laser parameters of the green transition S-4(3/2) -- \u3e I-4(15/2), The influence of excited-state absorption on this laser channel was determined. Furthermore, upconversion pump mechanisms using ground-state and excited-state absorption around 810 and 970 nm were investigated by direct measurements of excited-state absorption. The spectroscopic results confirm the pulsed room-temperature laser experiments on the S-4(3/2) -- \u3e I-5(5/2) transition. The lasers based on Er:LiYF4, Er:Y3Al5O12, and Er:Lu3Al5O12 were directly excited into the upper laser level by an excimer laser pumped dye laser in the blue spectral range. In Er:LiYF4, Er:KYF4, and Er:Y3Al5O12, laser action was achieved with two-step upconversion pumping by a Ti:sapphire laser and a krypton ion laser. In the case of the fluorides, the additional pumping with the krypton ion laser was not necessary. The laser emission wavelengths were 551 nm for Er:LiYF4, 561 nm for Er:Y3Al5012 and Er:Lu3Al5O12, and 562 nm for Er:KYF4. In addition, green quasi-cw laser emission of Er:LiYF4 pumped with an argon-ion laser was realized at room temperature

Tuning the Graphene on Ir(111) adsorption regime by Fe/Ir surface-alloying

A combined scanning tunneling microscopy, x-ray photoelectron spectroscopy, angle-resolved photoemission spectroscopy, and density functional theory study of graphene on a Fe-Ir(111) alloy with variable Ir concentration is presented. Starting from an intercalated Fe layer between the graphene and Ir(111) surface we find that graphene-substrate interaction can be fine-tuned by Fe-Ir alloying at the interface. When a critical Ir-concentration close to 0.25 is reached in the Fe layer, the Dirac cone of graphene is largely restored and can thereafter be tuned across the Fermi level by further increasing the Ir content. Indeed, our study reveals an abrupt transition between a chemisorbed phase at small Ir concentrations and a physisorbed phase above the critical concentration. The latter phase is highly reminiscent of the graphene on the clean Ir(111) surface. Furthermore, the transition is accompanied by an inversion of the graphene''s induced magnetization due to the coupling with the Fe atoms from antiferromagnetic when chemisorbed to weakly ferromagnetic in the physisorption regime, with spin polarizations whose magnitude may be tuned with the amount of Fe content