Cooperation in the Commons with Unobservable Actions

We model a dynamic common property resource game with unobservable actions and non-linear stock dependent costs. We propose a strategy profile that generates a worst perfect equilibrium in the punishment phase, thereby supporting cooperation under the widest set of conditions. We show under what set of parameter values for the discount rate, resource growth rate, harvest price, and the number of resource users, this strategy supports cooperation in the commons as a subgame perfect equilibrium. The strategy profile that we propose, which involves harsh punishment after a defection followed by forgiveness, is consistent with human behavior observed in experiments and common property resource case studies.Common property resource, cooperation, dynamic game, unobservable actions

Measures of fine tuning

Fine-tuning criteria are frequently used to place upper limits on the masses of superpartners in supersymmetric extensions of the standard model. However, commonly used prescriptions for quantifying naturalness have some important shortcomings. Motivated by this, we propose new criteria for quantifying fine tuning that can be used to place upper limits on superpartner masses with greater fidelity. In addition, our analysis attempts to make explicit the assumptions implicit in quantifications of naturalness. We apply our criteria to the minimal supersymmetric extension of the standard model, and we find that the scale of supersymmetry breaking can be larger than previous methods indicate.Comment: 15 pages, LaTex, 5 figures uuencoded, gz-compressed file. Minor revisions bring the archived manuscript into agreement with published versio

Exploration of potential objective and subjective daily indicators of sleep health in normal sleepers

Purpose: While the concept of "sleep health" has only recently been defined, how it relates to both subjective and objective sleep parameters is yet to be determined. The current study aimed to identify potential indicators of poorer sleep health, from subjective and objective daily sleep characteristics, in normal sleepers. Participants and methods: Eighty-three individuals aged 18-65 years with no history of sleep disorders, chronic physical or psychiatric illnesses, or substance misuse were recruited from the North of England. Secondary analysis of a series of standardized studies, which included psychometrics, actigraphy, and an in-lab polysomnography (PSG) component, was undertaken. Questions from several psychometric sleep scales were combined to create an aggregate measure of sleep health status. Subjective sleep continuity was assessed by 2-week sleep diary. Objective measures comprised two continuous weeks of actigraphy and two nights of in-lab PSG. Results: Significant negative correlations were evident between sleep health scores and both diary-derived subjective sleep latency (SL; diary) and actigraphy-derived SL (actigraphy). This was reflected by independent samples t-test between high and low sleep health groups. No relationships between sleep health and PSG parameters were observed. Regression analyses indicated sleep latencies from both the sleep diary and actigraphy as significant predictors, explaining 28.2% of the variance in sleep health. Conclusion: Perceived increases in SL appear to be a primary indicator of declining sleep health in normal sleepers. The majority of objective sleep parameters, including gross PSG sleep parameters, appear not to be sensitive to sleep health status in normal sleepers. Future research is needed to understand the physical and psychological correlates of sleep health in larger samples

Seeing the way: visual sociology and the distance runner's perspective

Employing visual and autoethnographic data from a two‐year research project on distance runners, this article seeks to examine the activity of seeing in relation to the activity of distance running. One of its methodological aims is to develop the linkage between visual and autoethnographic data in combining an observation‐based narrative and sociological analysis with photographs. This combination aims to convey to the reader not only some of the specific subcultural knowledge and particular ways of seeing, but also something of the runner's embodied feelings and experience of momentum en route. Via the combination of narrative and photographs we seek a more effective way of communicating just how distance runners see and experience their training terrain. The importance of subjecting mundane everyday practices to detailed sociological analysis has been highlighted by many sociologists, including those of an ethnomethodological perspective. Indeed, without the competence of social actors in accomplishing these mundane, routine understandings and practices, it is argued, there would in fact be no social order

Evaluation of Moderate and Low-Powered Lasers for Dispersing Double-Crested Cormorants from Their Night Roosts

The double-crested cormorant (Phalacrocorax auritus) is the primary avian predator on the southern catfish industry, estimated to cause $5 million in damage per year. To date, the most effective strategy for alleviating cormorant depredations in areas of intensive catfish production is coordinated dispersal of cormorant night roosts with pyrotechnics. Many of these night roosts are located in waterfowl refuges or wetland habitat leased for waterfowl hunting. Thus, there is an increasing concern about the effects of cormorant harassment efforts on waterfowl and other wildlife inhabiting these sites in cypress-swamp habitat. To address the need for a roost harassment device that was more species-specific, we evaluated two commercially available low- to moderate-powered lasers in a series of large-pen and field trials for their effectiveness in moving cormorants from test ponds and dispersing cormorants from their night roosts, respectively. In pen trials, laser beams directed at small groups of captive birds produced negligible effects, suggesting that the laser light was not highly aversive. This was consistent with a series of veterinary investigations suggesting no detectable ocular damage to cormorant eyes directly exposed to a selected laser at varying distances down to 1 m. During field trials both lasers, directed at roost trees after sunset, were consistently effective in dispersing cormorants in 1 to 3 evenings of harassment and is comparable to the harassment effort needed with pyrotechnics. Because laser treatment is completely silent and can be directed selectively at cormorants, these devices may be extremely useful for dispersing cormorants in sites where disturbance of other wildlife is a concern. Advantages and disadvantages of lasers relative to pyrotechnics are discussed

Activity patterns of free-ranging koalas (Phascolarctos cinereus) revealed by accelerometry

An understanding of koala activity patterns is important for measuring the behavioral response of this species to environmental change, but to date has been limited by the logistical challenges of traditional field methodologies. We addressed this knowledge gap by using tri-axial accelerometer data loggers attached to VHF radio collars to examine activity patterns of adult male and female koalas in a high-density population at Cape Otway, Victoria, Australia. Data were obtained from 27 adult koalas over two 7-d periods during the breeding season: 12 in the early-breeding season in November 2010, and 15 in the late-breeding season in January 2011. Multiple 15 minute observation blocks on each animal were used for validation of activity patterns determined from the accelerometer data loggers. Accelerometry was effective in distinguishing between inactive (sleeping, resting) and active (grooming, feeding and moving) behaviors. Koalas were more active during the early-breeding season with a higher index of movement (overall dynamic body acceleration [ODBA]) for both males and females. Koalas showed a distinct temporal pattern of behavior, with most activity occurring from mid-afternoon to early morning. Accelerometry has potential for examining fine-scale behavior of a wide range of arboreal and terrestrial species

Experienced demand does not affect subsequent sleep and the cortisol awakening response

Purpose: Stress is associated with subjective and objective sleep disturbances; however, it is not known whether stress disrupts sleep and relevant physiological markers of stress immediately after it is experienced. The present study examined whether demand, in the form of cognitive tasks, disrupted sleep and the cortisol awakening response (CAR), depending on whether it was experienced or just anticipated. Participants and Methods: Subjective and objective sleep was measured in 22 healthy adults on three nights (Nights 0– 2) in a sleep laboratory using sleep diaries and polysomnography. Saliva samples were obtained at awakening, +15, +30, +45 and +60 minutes on each subsequent day (Day 1– 3) and CAR measurement indices were derived: awakening cortisol levels, the mean increase in cortisol levels (MnInc) and total cortisol secretion (AUCG). On Night 1, participants were informed that they were required to complete a series of demanding cognitive tasks within the sleep laboratory during the following day. Participants completed the tasks as expected or unexpectedly performed sedentary activities. Results: Compared to the no-demand group, the demand group displayed significantly higher levels of state anxiety immediately completing the first task. There were no subsequent differences between the demand and no-demand groups in Night 2 subjective sleep continuity, objective sleep continuity or architecture, or on any Day 3 CAR measure. Conclusion: These results indicate that sleep and the CAR are not differentially affected depending on whether or not an anticipated stressor is then experienced. This provides further evidence to indicate that the CAR is a marker of anticipation and not recovery. In order to disrupt sleep, a stressor may need to be personally relevant or of a prolonged duration or intensity

Liposomal vaccines incorporating molecular adjuvants and intrastructural T-cell help promote the immunogenicity of HIV membrane-proximal external region peptides

An HIV vaccine capable of inducing high and durable levels of broadly neutralizing antibodies has thus far proven elusive. A promising antigen is the membrane-proximal external region (MPER) from gp41, a segment of the viral envelope recognized by a number of broadly neutralizing antibodies. Though an attractive vaccine target due to the linear nature of the epitope and its highly conserved sequence, MPER peptides are poorly immunogenic and may require display on membranes to achieve a physiological conformation matching the native virus. Here we systematically explored how the structure and composition of liposomes displaying MPER peptides impacts the strength and durability of humoral responses to this antigen as well as helper T-cell responses in mice. Administration of MPER peptides anchored to the surface of liposomes induced MPER-specific antibodies whereas MPER administered in oil-based emulsion adjuvants or alum did not, even when combined with Toll-like receptor agonists. High-titer IgG responses to liposomal MPER required the inclusion of molecular adjuvants such as monophosphoryl lipid A. Anti-MPER humoral responses were further enhanced by incorporating high-Tm lipids in the vesicle bilayer and optimizing the MPER density to a mean distance of ∼10–15 nm between peptides on the liposomes' surfaces. Encapsulation of helper epitopes within the vesicles allowed efficient “intrastructural” T-cell help, which promoted IgG responses to MPER while minimizing competing B-cell responses against the helper sequence. These results define several key properties of liposome formulations that promote durable, high-titer antibody responses against MPER peptides, which will be a prerequisite for a successful MPER-targeting vaccine.Bill & Melinda Gates FoundationNational Institutes of Health (U.S.) (AI091693

Serotonin transporter gene (SLC6A4) polymorphism and susceptibility to a home-visiting maternal-infant attachment intervention delivered by community health workers in South Africa: reanalysis of a randomized controlled trial

Background Clear recognition of the damaging effects of poverty on early childhood development has fueled an interest in interventions aimed at mitigating these harmful consequences. Psychosocial interventions aimed at alleviating the negative impacts of poverty on children are frequently shown to be of benefit, but effect sizes are typically small to moderate. However, averaging outcomes over an entire sample, as is typically done, could underestimate efficacy because weaker effects on less susceptible individuals would dilute estimation of effects on those more disposed to respond. This study investigates whether a genetic polymorphism of the serotonin transporter gene moderates susceptibility to a psychosocial intervention. Methods and findings We reanalyzed data from a randomized controlled trial of a home-visiting program delivered by community health workers in a black, isiXhosa-speaking population in Khayelitsha, South Africa. The intervention, designed to enhance maternal-infant attachment, began in the third trimester and continued until 6 mo postpartum. Implemented between April 1999 and February 2003, the intervention comprised 16 home visits delivered to 220 mother–infant dyads by specially trained community health workers. A control group of 229 mother–infant dyads did not receive the intervention. Security of maternal-infant attachment was the main outcome measured at infant age 18 mo. Compared to controls, infants in the intervention group were significantly more likely to be securely attached to their primary caregiver (odds ratio [OR] = 1.7, p = 0.029, 95% CI [1.06, 2.76], d = 0.29). After the trial, 162 intervention and 172 control group children were reenrolled in a follow-up study at 13 y of age (December 2012–June 2014). At this time, DNA collected from 279 children (134 intervention and 145 control) was genotyped for a common serotonin transporter polymorphism. There were both genetic data and attachment security data for 220 children (110 intervention and 110 control), of whom 40% (44 intervention and 45 control) carried at least one short allele of the serotonin transporter gene. For these 220 individuals, carrying at least one short allele of the serotonin transporter gene was associated with a 26% higher rate of attachment security relative to controls (OR = 3.86, p = 0.008, 95% CI [1.42, 10.51], d = 0.75), whereas there was a negligible (1%) difference in security between intervention and control group individuals carrying only the long allele (OR = 0.95, p = 0.89, 95% CI [0.45, 2.01], d = 0.03). Expressed in terms of absolute risk, for those with the short allele, the probability of secure attachment being observed in the intervention group was 84% (95% CI [73%, 95%]), compared to 58% (95% CI [43%, 72%]) in the control group. For those with two copies of the long allele, 70% (95% CI [59%, 81%]) were secure in the intervention group, compared to 71% (95% CI [60%, 82%]) of infants in the control group. Controlling for sex, maternal genotype, and indices of socioeconomic adversity (housing, employment, education, electricity, water) did not change these results. A limitation of this study is that we were only able to reenroll 49% of the original sample randomized to the intervention and control conditions. Attribution of the primary outcome to causal effects of intervention in the present subsample should therefore be treated with caution. Conclusions When infant genotype for serotonin transporter polymorphism was taken into account, the effect size of a maternal-infant attachment intervention targeting impoverished pregnant women increased more than 2.5-fold when only short allele carriers were considered (from d = 0.29 for all individuals irrespective of genotype to d = 0.75) and decreased 10-fold when only those carrying two copies of the long allele were considered (from d = 0.29 for all individuals to d = 0.03). Genetic differential susceptibility means that averaging across all participants is a misleading index of efficacy. The study raises questions about how policy-makers deal with the challenge of balancing equity (equal treatment for all) and efficacy (treating only those whose genes render them likely to benefit) when implementing psychosocial interventions