The sky is falling: evidence of a negativity bias in the social transmission of information

The method of serial reproduction has revealed that the social transmission of information is characterized by the gradual transformation of the original message. This transformation results from the preferential survival of certain types of information and the resolution of ambiguity. Here we present evidence of a bias favoring the social transmission of negatively-valenced information across multiple transmission episodes. Ninety-two, four-person chains transmitted a story containing unambiguously positive and unambiguously negative story events, along with ambiguous story events that could be interpreted positively or negatively. Analysis using mixed-effects modeling revealed the preferential survival of unambiguously negative events over positive events, and the increasingly negative resolution of ambiguous events across successive transmission episodes. Contrary to predictions, elevated state anxiety did not enhance the social transmission of negatively-valenced information. We also found that the survival of unambiguously negative story events was positively correlated with the negative resolution of ambiguous story events, reflecting a general negativity-bias in the social transmission of information.     

Mangrove Restoration: Do We Know Enough?

Mangrove restoration projects have been attempted, with mixed results, throughout the world. In this paper, I first examine goals of existing mangrove restoration projects and determine whether these goals are clear and adequate, and whether or not they account for the full range of biological diversity and ecological processes of mangrove ecosystems. Many restored mangrove forests resemble forest plantations rather than truly integrated ecosystems, but mangrove plantations can be a first step toward mangrove rehabilitation. Mangrove restoration projects that involve associated aquaculture or mariculture operations tend to be more likely to approximate the biological diversity and ecological processes of undisturbed mangrove ecosystems than are projects that focus only on the trees. These integrated restoration projects also provide a higher economic return than do silvicultural projects alone. Second, I briefly assess whether existing ecological data are sufficient to undergird successful restoration of mangal and define criteria for determining whether or not a mangrove ecosystem has been restored successfully. These criteria include characteristics of vegetation (forest) structure, levels of primary production, composition of associated animal communities, and hydrology. Finally, I suggest ways to improve mangrove restoration projects and identify key research needs required to support these efforts. Ecological theories derived from other wetland and upland systems rarely have been applied to either “basic” or “applied” mangrove forest studies, to the detriment of restoration projects, whereas lessons from restoration of the relatively species‐poor mangrove ecosystems could be beneficially applied to restoration projects in other contexts. An international database of mangrove restoration projects would reduce the likelihood that unsuccessful restoration projects would be repeated elsewhere. Clear criteria for evaluating success, greater accessibility of information by managers in the developing world, intensified international cooperation, and application of relevant ecological theories will improve the success rate of mangrove restoration projects.     

Potential applications of urinary C-peptide of insulin for comparative energetics research

The study of comparative energetics offers a valuable way to identify broad ecological principles and assess the functional significance of energetic adaptations during the course of evolution. Yet, the quantification of energetic status for nonhuman primates under natural conditions remains one of the most challenging aspects of comparative energetics research. Here, we report on the development of a noninvasive field method for measuring energetic status in great apes, humans, and possibly other nonhuman primates. Specifically, we have explored measurement of a urinary metabolite of insulin (C-peptide) as a physiological marker of energetic condition in chimpanzees and orangutans. We performed three validation studies and successfully measured C-peptide in urine samples from captive chimpanzees, wild chimpanzees, and wild orangutans. Urinary C-peptide measures gave indications of being a reliable signal of energetic status in both species. For chimpanzees and orangutans in the wild, baseline urinary C-peptide levels were higher during periods of fruit abundance than periods of low fruit availability. Urinary C-peptide levels were also higher for well-fed captive chimpanzees compared with wild chimpanzees. Although sample size was small, top-ranking male chimpanzees showed higher C-peptide levels in the wild than low-ranking males only during the period of fruit abundance. These preliminary results indicate that further development of the urinary C-peptide method could expand opportunities to quantify energetic condition for great apes in the wild and generate new data for comparative research. We highlight specific applications for studying great ape reproduction as well as the nutritional ecology of human foragers.     

The incentive gap: LULUCF and the Kyoto mechanism before and after Durban

To‐date, forest resource‐based carbon accounting in land use, land use change and forestry (LULUCF) under the United Nations Framework Convention on Climate Change (UNFCCC), Kyoto Protocol (KP), European Union (EU) and national level emission reduction schemes considers only a fraction of its potential and fails to adequately mobilize the LULUCF sector for the successful stabilization of atmospheric greenhouse gas (GHG) concentrations. Recent modifications at the 2011 COP17 meetings in Durban have partially addressed this basic problem, but leave room for improvement. The presence of an Incentive Gap (IG) continues to justify reform of the LULUCF carbon accounting framework. Frequently neglected in the climate change mitigation and adaptation literature, carbon accounting practices ultimately define the nuts and bolts of what counts and which resources (forest, forest‐based or other) are favored and utilized. For Annex I countries in the Kyoto Mechanism, the Incentive Gap under forest management (FM) is significantly large: some 75% or more of potential forestry‐based carbon sequestration is not effectively incentivized or mobilized for climate change mitigation and adaptation (Ellison et al. 2011a). In this paper, we expand our analysis of the Incentive Gap to incorporate the changes agreed in Durban and encompass both a wider set of countries and a larger set of omitted carbon pools. For Annex I countries, based on the first 2 years of experience in the first Commitment Period (CP1) we estimate the IG in FM at approximately 88%. Though significantly reduced in CP2, the IG remains a problem. Thus our measure of missed opportunities under the Kyoto and UNFCCC framework – despite the changes in Durban – remains important. With the exception perhaps of increased energy efficiency, few sinks or sources of reduced emissions can be mobilized as effectively and efficiently as forests. Thus, we wonder at the sheer magnitude of this underutilized resource.     

MicroRNA-1 Downregulation Increases Connexin 43 Displacement and Induces Ventricular Tachyarrhythmias in Rodent Hypertrophic Hearts

Downregulation of the muscle-specific microRNA-1 (miR-1) mediates the induction of pathologic cardiac hypertrophy. Dysfunction of the gap junction protein connexin 43 (Cx43), an established miR-1 target, during cardiac hypertrophy leads to ventricular tachyarrhythmias (VT). However, it is still unknown whether miR-1 and Cx43 are interconnected in the pro-arrhythmic context of hypertrophy. Thus, in this study we investigated whether a reduction in the extent of cardiac hypertrophy could limit the pathological electrical remodeling of Cx43 and the onset of VT by modulating miR-1 levels. Wistar male rats underwent mechanical constriction of the ascending aorta to induce pathologic left ventricular hypertrophy (LVH) and afterwards were randomly assigned to receive 10mg/kg valsartan, VAL (LVH+VAL) delivered in the drinking water or placebo (LVH) for 12 weeks. Sham surgery was performed for control groups. Programmed ventricular stimulation reproducibly induced VT in LVH compared to LVH+VAL group. When compared to sham controls, rats from LVH group showed a significant decrease of miR-1 and an increase of Cx43 expression and its ERK1/2-dependent phosphorylation, which displaces Cx43 from the gap junction. Interestingly, VAL administration to rats with aortic banding significantly reduced cardiac hypertrophy and prevented miR-1 down-regulation and Cx43 up-regulation and phosphorylation. Gain- and loss-of-function experiments in neonatal cardiomyocytes (NCMs) in vitro confirmed that Cx43 is a direct target of miR-1. Accordingly, in vitro angiotensin II stimulation reduced miR-1 levels and increased Cx43 expression and phosphorylation compared to un-stimulated NCMs. Finally, in vivo miR-1 cardiac overexpression by an adenoviral vector intra-myocardial injection reduced Cx43 expression and phosphorylation in mice with isoproterenol-induced LVH. In conclusion, miR-1 regulates Cx43 expression and activity in hypertrophic cardiomyocytes in vitro and in vivo. Treatment of pressure overload-induced myocyte hypertrophy reduces the risk of life-threatening VT by normalizing miR-1 expression levels with the consequent stabilization of Cx43 expression and activity within the gap junction.     

Rapid inventory of the ant assemblage in a temperate hardwood forest: species composition and assessment of sampling methods

Ants are key indicators of ecological change, but few studies have investigated how ant assemblages respond to dramatic changes in vegetation structure in temperate forests. Pests and pathogens are causing widespread loss of dominant canopy tree species; ant species composition and abundance may be very sensitive to such losses. Before the experimental removal of red oak trees to simulate effects of sudden oak death and examine the long-term impact of oak loss at the Black Rock Forest (Cornwall, NY), we carried out a rapid assessment of the ant assemblage in a 10-ha experimental area. We also determined the efficacy in a northern temperate forest of five different collecting methods--pitfall traps, litter samples, tuna fish and cookie baits, and hand collection--routinely used to sample ants in tropical systems. A total of 33 species in 14 genera were collected and identified; the myrmecines, Aphaenogaster rudis and Myrmica punctiventris, and the formicine Formica neogagates were the most common and abundant species encountered. Ninety-four percent (31 of 33) of the species were collected by litter sampling and structured hand sampling together, and we conclude that, in combination, these two methods are sufficient to assess species richness and composition of ant assemblages in northern temperate forests. Using new, unbiased estimators, we project that 38-58 ant species are likely to occur at Black Rock Forest. Loss of oak from these forests may favor Camponotus species that nest in decomposing wood and open habitat specialists in the genus Lasius.