The RETHINK Study: Could pain catastrophising explain why some women are more likely to attend hospital during the latent phase of labour.

OBJECTIVE: To examine the prevalence of pain catastrophising and identify whether it impacts on the timing of hospital admission when in labour. METHODS: A longitudinal cohort study. Nulliparous women, experiencing an uncomplicated pregnancy in England, were recruited between 25 and 33 weeks gestation. Participants completed two online questionnaires, (1) on recruitment, including the Pain Catastrophizing Scale (PCS) and the Wijma Delivery Expectancy Questionnaire (WDEQ-A) (2) at three weeks postnatal. RESULTS: A total of 389 eligible participants entered the study. The percentage of women who were pain catastrophisers (PCS ≥ 20) was 28.1 %, while 7.6 % had a high pain catastrophising score (PCS ≥ 30). There was no association between pain catastrophising and the timing of hospital admission. The percentage of women reporting fear of childbirth (WDEQ-A score of ≥ 85) was 10.6 %. Fear of childbirth was highly associated with PCS scores (p <.001) at both the lower (≥20) and higher (≥30) thresholds. CONCLUSION: Although not statistically significant, there was a tendency for women who pain catastrophise to present to hospital in the latent phase. The highly significant association between PCS and WDEQ-A scores has implications for the identification of these women and suggests that the PCS can be used as a screening tool to identify those women who have heightened fear around pain and who may also go on to develop clinically relevant fear of childbirth. Further studies are needed to confirm the acceptability of the PCS as a screening tool with women.

Neutron star mass estimates from gamma-ray eclipses in spider millisecond pulsar binaries.

Reliable neutron star mass measurements are key to determining the equation of state of cold nuclear matter, but such measurements are rare. Black widows and redbacks are compact binaries consisting of millisecond pulsars and semi-degenerate companion stars. Spectroscopy of the optically bright companions can determine their radial velocities, providing inclination-dependent pulsar mass estimates. Although inclinations can be inferred from subtle features in optical light curves, such estimates may be systematically biased due to incomplete heating models and poorly understood variability. Using data from the Fermi Large Area Telescope, we have searched for gamma-ray eclipses from 49 spider systems, discovering significant eclipses in 7 systems, including the prototypical black widow PSR B1957+20. Gamma-ray eclipses require direct occultation of the pulsar by the companion, and so the detection, or significant exclusion, of a gamma-ray eclipse strictly limits the binary inclination angle, providing new robust, model-independent pulsar mass constraints. For PSR B1957+20, the eclipse implies a much lighter pulsar (1.81 ± 0.07 solar masses) than inferred from optical light curve modelling.

Natural and Anthropogenic Processes Affecting Domestic Groundwater Quality within the Northwestern Appalachian Basin.

Domestic wells serve as the primary drinking-water source for rural residents in the northern Appalachian Basin (NAB), despite a limited understanding of contaminant distributions in groundwater sources. We employ a newly collected dataset of 216 water samples from domestic wells in Ohio and West Virginia and an integrated contaminant-source attribution method to describe water quality in the western NAB and characterize key agents influencing contaminant distributions. Our results reveal arsenic and nitrate concentrations above federal maximum contaminant levels (MCLs) in 6.8 and 1.3% of samples and manganese concentrations above health advisory in 7.3% of samples. Recently recharged groundwaters beneath upland regions appear vulnerable to surface-related impacts, including nitrate pollution from agricultural activities and salinization from road salting and domestic sewage sources. Valley regions serve as terminal discharge points for long-residence-time groundwaters, where mixing with basin brines is possible. Arsenic impairments occurred in alkaline groundwaters with major-ion compositions altered by ion exchange and in low-oxygen metal-rich groundwaters. Mixing with as much as 4-10% of mine discharge-like waters was observed near coal mining operations. Our study provides new insights into key agents of groundwater impairment in an understudied region of the NAB and presents an integrated approach for contaminant-source attribution applicable to other regions of intensive resource extraction.

GROW: a model for mentorship to advance women's leadership in global health.

In this essay, we discuss the under-representation of women in leadership positions in global health (GH) and the importance of mentorship to advance women's standing in the field. We then describe the mentorship model of GROW, Global Research for Women. We describe the theoretical origins of the model and an adapted theory of change explaining how the GROW model for mentorship advances women's careers in GH. We present testimonials from a range of mentees who participated in a pilot of the GROW model since 2015. These mentees describe the capability-enhancing benefits of their mentorship experience with GROW. Thus, preliminary findings suggest that the GROW mentorship model is a promising strategy to build women's leadership in GH. We discuss supplemental strategies under consideration and next steps to assess the impact of GROW, providing the evidence to inform best practices for curricula elsewhere to build women's leadership in GH.

Correlation of the functional difficulties questionnaire (FDQ-9) with dynamic balance using the SMART instrumented wobbleboard.

OBJECTIVES: To investigate concurrent validity of the Functional Difficulties Questionnaire (FDQ-9) using balance tasks on the SMARTwobbleboard. Poor balance is associated with reduced physical activity which may impact on quality of life. There is a requirement to use simple tests to assess balance so that suitable interventions can be employed to ameliorate poor balance and enhance uptake of physical activity. DESIGN: Observational study employing 30 healthy volunteers who completed the FDQ-9 and undertook three balance tasks on the SMARTwobbleboard: double leg stance eyes open (DLSEO); double leg stance eyes closed (DLSEC) and single leg stance eyes open (SLSEO). RESULTS: There were moderate significant correlations between the FDQ-9 and DLSEO and SLSEO. There were significant between group differences in dynamic balance for participants with FDQ-9 ≤ 18 (indicative of no functional difficulties) and FDQ-9 ≥ 19 (indicative of one or more functional difficulties) for DLSEO and SLSEO. CONCLUSIONS: Significant moderate correlations were recorded between the FDQ-9 and the SMARTwobbleboard in healthy adults indicating a relationship between dynamic balance and questionnaire scores (DLSEO and SLSEO). Initial findings contribute to the concurrent validity of the FDQ-9 which could also be used as a simple tool for assessing balance.

Vertebrate herbivory impacts seedling recruitment more than niche partitioning or density-dependent mortality.

In tropical forests, resource-based niches and density-dependent mortality are mutually compatible mechanisms that can act simultaneously to limit seedling populations. Differences in the strengths of these mechanisms will determine their roles in maintaining species coexistence. In the first assessment of these mechanisms in a Congo Basin forest, we quantified their relative strengths and tested the extent to which density-dependent mortality is driven by the distance-dependent behavior of seed and seedling predators predicted by the Janzen-Connell hypothesis. We conducted a large-scale seed addition experiment for five randomly selected tropical tree species, caging a subset of seed addition quadrats against vertebrate predators. We then developed models to assess the mechanisms that determine seedling emergence (three months after seed addition) and survival (two years after seed addition). As predicted, both niche differentiation and density-dependent mortality limited seedling recruitment, but predation had the strongest effects on seedling emergence and survival. Seedling species responded differently to naturally occurring environmental variation among sites, including variation in light levels and soil characteristics, supporting predictions of niche-based theories of tropical tree species coexistence. The addition of higher densities of seeds into quadrats initially led to greater seedling emergence, but survival to two years decreased with seed density. Seed and seedling predation reduced recruitment below levels maintained by density-dependent mortality, an indication that predators largely determine the population size of tree seedlings. Seedling recruitment was unrelated to the distance to or density of conspecific adult trees, suggesting that recruitment patterns are generated by generalist vertebrate herbivores rather than the specialized predators predicted by the Janzen-Connell hypothesis. If the role of seed and seedling predation in limiting seedling recruitment is a general phenomenon, then the relative abundances of tree species might largely depend on species-specific adaptations to avoid, survive, and recover from damage induced by vertebrate herbivores. Likewise, population declines of herbivorous vertebrate species (many of which are large and hunted) may trigger shifts in species composition of tropical forests.

Cerebral malaria protection in mice by species-specific Plasmodium coinfection is associated with reduced CC chemokine levels in the brain.

Cerebral malaria is a major pathological complication of Plasmodium falciparum infection in humans. Epidemiological observations have suggested that the clinical evolution of P. falciparum infections may be influenced by the concurrent presence of another Plasmodium species. Infection of susceptible mouse strains with P. berghei ANKA (PbA) provides an experimental model of cerebral malaria which has been extensively used to identify different components of the immune system involved in cerebral malaria. This model has also been employed to investigate the influence of experimental mixed-Plasmodium-species infections on the expression of cerebral malaria; PbA-induced cerebral malaria is completely inhibited by the simultaneous presence of P. yoelii yoelii 17 X clone 1.1 parasites, and accumulation of CD8(+) T cells in the brain vasculature is abolished. We investigated whether brain levels of CD8(+) -T-cell-chemoattractant chemokines CCL3, CCL4 and CCL5 are reduced in these protected coinfected mice compared with PbA-infected mice. Coinfected mice were found to exhibit significantly reduced levels of all three chemokines on day 6 post-infection. This finding may contribute to the abolition of the accumulation of CD8(+) T cells in the brain vasculature and the prevention of the development of cerebral malaria in coinfected mice.

Decoupling the effects of logging and hunting on an afrotropical animal community.

In tropical forests, hunting nearly always accompanies logging. The entangled nature of these disturbances complicates our ability to resolve applied questions, such as whether secondary and degraded forest can sustain populations of tropical animals. With the expansion of logging in central Africa, conservation depends on knowledge of the individual and combined impacts of logging and hunting on animal populations. Our goals were (1) to decouple the effects of selective logging and hunting on densities of animal guilds, including apes, duikers, monkeys, elephant, pigs, squirrels, and large frugivorous and insectivorous birds and (2) to compare the relative importance of these disturbances to the effects of local-scale variation in forest structure and fruit abundance. In northern Republic of Congo, we surveyed animals along 30 transects positioned in forest disturbed by logging and hunting, logging alone, and neither logging nor hunting. While sampling transects twice per month for two years, we observed 47 179 animals of 19 species and eight guilds in 1154 passages (2861 km). Species densities varied by as much as 480% among forest areas perturbed by logging and/or hunting, demonstrating the strong effects of these disturbances on populations of some species. Densities of animal guilds varied more strongly with disturbance type than with variation in forest structure, canopy cover, and fruit abundance. Independently, logging and hunting decreased density of some guilds and increased density of others: densities varied from 44% lower (pigs) to 90% higher (insectivorous birds) between logged and unlogged forest and from 61% lower (apes) to 77% higher (frugivorous birds) between hunted and unhunted forest. Their combined impacts exacerbated decreases in populations of some guilds (ape, duiker, monkey, and pig), but counteracted one another for others (squirrels, insectivorous and frugivorous birds). Together, logging and hunting shifted the relative abundance of the animal community away from large mammals toward squirrels and birds. Logged forest, even in the absence of hunting, does not maintain similar densities as unlogged forest for most animal guilds. To balance conservation with the need for economic development and wild meat in tropical countries, landscapes should be spatially managed to include protected areas, community hunting zones, and production forest.

War-related stressors are associated with asthma risk among older Kuwaitis following the 1990 Iraqi invasion and occupation.

BACKGROUND: Contemporary warfare involving civilian populations is a growing public health concern. In addition to the psychological impact, war-related trauma may result in physiological alterations and even broader health effects. Associations were examined between war-related stressors and incident asthma in elderly Kuwaiti civilians following the Iraqi invasion. METHODS: A random sample of all Kuwaiti nationals aged 50-69 years on the day prior to the invasion were identified. Among the 7873 meeting eligibility criteria, 5567 (71%) agreed to participate and 5028 completed the questionnaire (91% of those eligible). Of these, 3759 were in Kuwait during the invasion, of whom 2294 were alive at follow-up. After exclusions for prevalent asthma or missingness on covariates, 2066 were available for analysis. War-related experiences were summarised into a continuous score using Rasch modelling. Relative Cox proportional hazard rates (HR) were calculated for asthma adjusting for covariates. RESULTS: Over 13 years of follow-up, physician-diagnosed asthma was reported by 66/996 (6.6%) men and 104/1070 (9.7%) women. In models adjusted for gender, socioeconomic status, smoking, BMI, and air pollution related to burning oil fires, those reporting highest stress exposure were more than twice as likely to report asthma (HR 2.3, 95% CI 1.3, 3.9) compared to civilians reporting no stressors. Experiences were more salient when anchored to fear for loss of life. CONCLUSIONS: War-related trauma is associated with increased asthma risk in these elderly civilians. Although prior research has documented the significant and persistent psychological toll of war, these findings implicate even broader health effects.

Logging concessions can extend the conservation estate for Central African tropical forests.

The management of tropical forest in timber concessions has been proposed as a solution to prevent further biodiversity loss. The effectiveness of this strategy will likely depend on species-specific, population-level responses to logging. We conducted a survey (749 line transects over 3450 km) in logging concessions (1.2 million ha) in the northern Republic of Congo to examine the impact of logging on large mammal populations, including endangered species such as the elephant (Loxodonta africana), gorilla (Gorilla gorilla), chimpanzee (Pan troglodytes), and bongo (Tragelaphus eurycerus). When we estimated species abundance without consideration of transect characteristics, species abundances in logged and unlogged forests were not different for most species. When we modeled the data with a hurdle model approach, however, analyzing species presence and conditional abundance separately with generalized additive models and then combining them to calculate the mean species abundance, species abundance varied strongly depending on transect characteristics. The mean species abundance was often related to the distance to unlogged forest, which suggests that intact forest serves as source habitat for several species. The mean species abundance responded nonlinearly to logging history, changing over 30 years as the forest recovered from logging. Finally the distance away from roads, natural forest clearings, and villages also determined the abundance of mammals. Our results suggest that logged forest can extend the conservation estate for many of Central Africa's most threatened species if managed appropriately. In addition to limiting hunting, logging concessions must be large, contain patches of unlogged forest, and include forest with different logging histories.

Bushmeat supply and consumption in a tropical logging concession in northern Congo.

Unsustainable hunting of wildlife for food empties tropical forests of many species critical to forest maintenance and livelihoods of forest people. Extractive industries, including logging, can accelerate exploitation of wildlife by opening forests to hunters and creating markets for bushmeat. We monitored human demographics, bushmeat supply in markets, and household bushmeat consumption in five logging towns in the northern Republic of Congo. Over 6 years we recorded 29,570 animals in town markets and collected 48,920 household meal records. Development of industrial logging operations led to a 69% increase in the population of logging towns and a 64% increase in bushmeat supply. The immigration of workers, jobseekers, and their families altered hunting patterns and was associated with increased use of wire snares and increased diversity in the species hunted and consumed. Immigrants hunted 72% of all bushmeat, which suggests the short-term benefits of hunting accrue disproportionately to "outsiders" to the detriment of indigenous peoples who have prior, legitimate claims to wildlife resources. Our results suggest that the greatest threat of logging to biodiversity may be the permanent urbanization of frontier forests. Although enforcement of hunting laws and promotion of alternative sources of protein may help curb the pressure on wildlife, the best strategy for biodiversity conservation may be to keep saw mills and the towns that develop around them out of forests.

Kinetic assay for characterization of spleen tyrosine kinase activity and inhibition with recombinant kinase and crude cell lysates.

Spleen tyrosine kinase (Syk) is involved in the activation of cells implicated in allergic or autoimmune diseases and certain cancers. Therefore, Syk inhibitors may prove to be effective in treating diseases where Syk activity or expression is increased or deregulated. We developed a continuous and direct (noncoupled) fluorescence intensity assay for measuring Syk activity using purified recombinant enzyme or crude lysates generated from anti-immunoglobulin M (IgM) antibody-treated RAMOS cells. The assay is based on the chelation-enhanced fluorophore 8-hydroxy-5-(N,N-dimethylsulfonamido)-2-methylquinoline (referred to as Sox), which has been incorporated into a peptide substrate selected for robust detection of Syk activity. This homogeneous assay is simple to use, provides considerably more information, and has been adapted to a 384-well, low-volume microtiter plate format that can be used for the high-throughput identification and kinetic characterization of Syk inhibitors. The assay can be performed with a wide range of adenosine triphosphate (ATP) concentrations and, therefore, can be used to analyze ATP-competitive and ATP-noncompetitive/allosteric kinase inhibitors. Measurement of Syk activity in RAMOS crude cell lysates or immunoprecipitation (IP) capture formats may serve as a physiologically more relevant enzyme source. These Sox-based continuous and homogeneous assays provide a valuable set of tools for studying Syk signaling and for defining inhibitors that may be more effective in controlling disease.

Prevalence estimate of intimate partner violence in Jordan.

This study examined the prevalence of intimate partner violence in Jordan among a sample of 517 reproductive health clinic attendees. Intimate partner violence was measured using the World Health Organization's domestic violence questionnaire which was modified by the results of focus group discussions conducted in Amman. The percentages of women experiencing at least 1 form of control or violence since marriage were: control, 97.2%; psychological violence, 73.4%; physical violence, 31.2%; and sexual violence, 18.8%. Modifications of the WHO questionnaire were needed to measure control and psychological violence in Jordan. Similar modifications might be required when conducting research in the Region.

Prevalence estimate of intimate partner violence in Jordan

This study examined the prevalence of intimate partner violence in Jordan among a sample of 517 reproductive health clinic attendees. Intimate partner violence was measured using the World Health Organization's domestic violence questionnaire which was modified by the results of focus group discussions conducted in Amman. The percentages of women experiencing at least 1 form of control or violence since marriage were: control, 97.2%; psychological violence, 73.4%; physical violence, 31.2%; and sexual violence, 18.8%. Modifications of the WHO questionnaire were needed to measure control and psychological violence in Jordan. Similar modifications might be required when conducting research in the Region

Plants as reef fish: fitting the functional form of seedling recruitment.

The life histories of many species depend first on dispersal to local sites and then on establishment. After dispersal, density-independent and density-dependent mortalities modify propagule supply, determining the number of individuals that establish. Because multiple factors influence recruitment, the dichotomy of propagule versus establishment limitation is best viewed as a continuum along which the strength of propagule or establishment limitation changes with propagule input. To evaluate the relative importance of seed and establishment limitation for plants, we (1) describe the shape of the recruitment function and (2) use limitation and elasticity analyses to quantify the sensitivity of recruitment to perturbations in seed limitation and density-independent and density-dependent mortality. Using 36 seed augmentation studies for 18 species, we tested four recruitment functions against one another. Although the linear model (accounting for seed limitation and density-independent mortality) fitted the largest number of studies, the nonlinear Beverton-Holt model (accounting for density-dependent mortality) performed better at high densities of seed augmentation. For the 18 species, seed limitation constrained population size more than other sources of limitation at ambient conditions. Seedling density reached saturation with increasing seed density in many studies, but at such high densities that seedling density was primarily limited by seed availability rather than microsite availability or density dependence.

Are plant populations seed limited? A critique and meta-analysis of seed addition experiments.

We examine the relative importance of processes that underlie plant population abundance and distribution. Two opposing views dominate the field. One posits that the ability to establish at a site is determined by the availability of suitable microsites (establishment limitation), while the second asserts that recruitment is limited by the availability of seeds (seed limitation). An underlying problem is that establishment and seed limitation are typically viewed as mutually exclusive. We conducted a meta-analysis of seed addition experiments to assess the relative strength of establishment and seed limitation to seedling recruitment. We asked (1) To what degree are populations seed and establishment limited? (2) Under what conditions (e.g., habitats and life-history traits) are species more or less limited by each? (3) How can seed addition studies be better designed to enhance our understanding of plant recruitment? We found that, in keeping with previous studies, most species are seed limited. However, the effects of seed addition are typically small, and most added seeds fail to recruit to the seedling stage. As a result, establishment limitation is stronger than seed limitation. Seed limitation was greater for large-seeded species, species in disturbed microsites, and species with relatively short-lived seed banks. Most seed addition experiments cannot assess the relationship between number of seeds added and number of subsequent recruits. This shortcoming can be overcome by increasing the number and range of seed addition treatments.

Contrasting roles of neuronal Msk1 and Rsk2 in Bad phosphorylation and feedback regulation of Erk signalling.

Activated extracellular-signal-regulated kinase (Erk) phosphorylates and activates downstream kinases including ribosomal S6 kinase 2 (Rsk2/RPS6KA3) and mitogen- and stress-activated kinase 1 (Msk1, RPS6KA5). Rsk2 plays an important role in neuronal plasticity, as patients with Coffin-Lowry syndrome, where Rsk2 is dysfunctional, have impaired cognitive function. However, the relative role of neuronal Rsk2 and Msk1 in activating proteins downstream of Erk is unclear. In PC12 cells and in cortical neurones, the calcium ionophore A23187-induced phosphorylation of Erk, Msk1, Rsk2 and also the Bcl-2-associated death protein (Bad), which protects against neurotoxicity. Specific knockdown of Msk1 with small interfering RNA reduced the ability of A23187 to induce Bad phosphorylation in both PC12 cells and cortical neurones. Conversely, specific knockdown of Rsk2 potentiated Bad phosphorylation following A23187 treatment, and also elevated Erk phosphorylation in both cell types. This indicates that Msk1 rather than Rsk2 mediates neuronal Bad phosphorylation following Ca(2+) influx and implicates Rsk2 in a negative-feedback regulation of Erk activity.

Differences in the neurochemical characteristics of the cortex and striatum of mice with cerebral malaria.

Fatal murine cerebral malaria is an encephalitis and not simply a local manifestation in the brain of a systemic process. Histopathologically, murine cerebral malaria has been characterized by monocyte adherence to the endothelium of the microvasculature, activation of microglial cells, swelling of endothelial cell nuclei, microvasculature damage, and breakdown of the blood-brain barrier with cerebral oedema. Brain parenchymal cells have been proposed to be actively involved in the pathogenesis of murine cerebral malaria. We, therefore, compared the neurochemical characteristics of Plasmodium berghei ANKA-infected mice with controls to determine whether cerebral malarial infection significantly impairs specific neuronal populations. Between 6 and 7 days after infection, we found a significant loss of neurones containing substance P, with preservation of cells containing somatostatin, neuropeptide Y and calbindin in the striatum of infected mice compared with controls. In the cortex of infected mice, we found a significant reduction in the number of cells containing substance P, somatostatin and neuropeptide Y. The number of calbindin-containing neurones was unchanged. This study found significant changes in the neurochemical characteristics of the cortex and striatum of mice infected with P. berghei ANKA, which may contribute to their cerebral symptoms.

N-methyl-D-aspartate and brain-derived neurotrophic factor induce distinct profiles of extracellular signal-regulated kinase, mitogen- and stress-activated kinase, and ribosomal s6 kinase phosphorylation in cortical neurons.

Stimulation of N-methyl-D-aspartate (NMDA) receptors is believed to underlie long-term memory formation, and excessive NMDA receptor activation has been linked to several neuropathological conditions. Phosphorylation and activation of p42/44 mitogen-activated protein kinase (ERK) is believed to mediate many of these effects, but the downstream targets of ERK in response to NMDA activation have not been determined. In primary cultures of rat cortical neurons, we found that NMDA was able to elevate phosphorylation of mitogen- and stress-activated kinase 1 (MSK1) as well as ERK. Likewise, brain-derived neurotrophic factor (BDNF) treatment increased phosphorylation of MSK1 and ERKs. The NMDA-induced MSK1 phosphorylation was sensitive to the MEK inhibitor 2'-amino-3'-methoxyflavone (PD98059) and the p38 inhibitor 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB203580). MSK1 activation by NMDA was transient, although ERK remained phosphorylated within the neuronal cytoplasm for several hours. Although BDNF increased ribosomal S6 kinase (RSK) phosphorylation, NMDA had no discernable effect on the phosphorylation of RSKs. Thus, phosphorylation and activation of MSK1 but not RSK could be an important step in the pathway linking NMDA-induced ERK phosphorylation to the activation of transcription factors required for the formation of long-term memory.

Fruiting trees as dispersal foci in a semi-deciduous tropical forest.

Quantification of seed rain patterns is an initial step toward explaining variation in plant recruitment, and consequently, organization of forest communities. Spatially contagious patterns of seed deposition, where seeds are patchily dispersed with some sites receiving relatively high densities and others receiving low densities of seeds, may be a common phenomenon for which we have very little knowledge. For example, prior feeding events by frugivores (monkeys and birds) combined with transport and dispersal of seeds to other fruiting trees may result in the contagious deposition of non-conspecific seeds below them. Here, we examined whether fruiting trees act as dispersal foci in the semi-deciduous tropical rainforest of the Dja Reserve, Cameroon. Seed rain was sampled below the canopies of nine tree species: three typically dispersed by large, frugivorous birds, three dispersed by monkeys, and three dispersed by wind. We found no evidence that monkeys generate spatially contagious patterns of seed rain under fruiting trees at which they feed. However, we found that rates of deposition of non-conspecific seeds and species richness of seeds delivered by birds (hornbills and turacos) were significantly greater during fruiting than non-fruiting periods, and significantly greater under fruiting individuals of bird-dispersed tree species than under fruiting individuals of monkey- or wind-dispersed tree species. Additionally, during fruiting periods, the composition of non-conspecific seed rain under bird-dispersed tree species was more similar to other bird-dispersed trees than to monkey- or wind-dispersed tree species. The contagious dispersal of non-conspecific seeds to fruiting, bird-dispersed trees leads to higher seed densities under fruiting trees than those caused by local seed production. Non-conspecific seeds deposited in high densities may experience increased seed mortality even far from parent trees if predators are generalists. Alternatively, in the absence of complete density-dependent mortality, contagious seed dispersal could result in associations among species dispersed by the same dispersal agent.