Task syndromes: linking personality and task allocation in social animal groups

Studies of eusocial insects have extensively investigated two components of task allocation: how individuals distribute themselves among different tasks in a colony and how the distribution of labor changes to meet fluctuating task demand. While discrete age- and morphologically-based task allocation systems explain much of the social order in these colonies, the basis for task allocation in non-eusocial organisms and within eusocial castes remains unknown. Building from recent advances in the study of among-individual variation in behavior (i.e., animal personalities), we explore a potential mechanism by which individuality in behaviors unrelated to tasks can guide the developmental trajectories that lead to task specialization. We refer to the task-based behavioral syndrome that results from the correlation between the antecedent behavioral tendencies and task participation as a task syndrome. In this review, we present a framework that integrates concepts from a long history of task allocation research in eusocial organisms with recent findings from animal personality research to elucidate how task syndromes and resulting task allocation might manifest in animal groups. By drawing upon an extensive and diverse literature to evaluate the hypothesized framework, this review identifies future areas for study at the intersection of social behavior and animal personality.

P4672Current outcome of chronic thromboembolic pulmonary hypertension in Spain

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) treatment has evolved over the last decade. Increasing evidence regarding new therapeutic developments has shown clinical benefit among these patients in different scenarios. However, there is scarce information about the long-term impact of these achievements in a real-life population on a national scale. We aimed to analyze the impact of current CTEPH therapies on survival in Spain.

Methods

We prospectively collected epidemiological, clinical and prognostic data from CTEPH patients consecutively included in the Spanish REHAP registry from January 1, 2007, to December 31, 2017. All-cause mortality data were gathered during this period.

Results

Eight hundred thirteen patients were included. The mean age was 61 (15) years and 58.1% were women. Out of the 813 patients, 537 (66%) were referred to an expert PH-center. Overall, 245 (30.1%) patients were selected for surgery and 52 (6.4%) for percutaneous treatment and 452 (60.5%) received medical treatment exclusively with specific PH drugs. Survival rates of patients who underwent an invasive procedure (pulmonary thrombendarterectomy or balloon pulmonary angioplasty) were remarkably high.

Figure 1. Cumulative survival from date

Conclusions

Patients who underwent pulmonary thrombendarterectomy or balloon pulmonary angioplasty associated a better outcome.

Acknowledgement/Funding

We gratefully acknowledge all investigators of the REHAP Registry. We express our gratitude to Actelion, Ferrer, GlaxoSmithKline (GSK) and Merck Sharp

Differential binding capacity and internalisation of bacterial substrates as factors in growth rate of Acanthamoeba spp

Acanthamoeba spp. are free-living predators that selectively feed on bacteria. Adherence of the bacterial food source to the trophozoite membrane is followed by internalisation and digestion. Through co-cultivation of A. castellanii and A. polyphaga, individually, with Xanthomonas maltophilia, Escherichia coli, Staphylococcus epidermidis and Pseudomonas aeruginosa (despite the amoebicidal properties of the latter organism), specificity with regard to the preferred bacterial substrate was judged. X. maltophilia and P. aeruginosa adhered almost immediately forming a multilayered mantle of bacilli around trophozoites of both species of amoebae. E. coli adhered to fewer trophozoites and in smaller numbers. X. maltophilia was readily internalised after co-cultivation for 8 h, whereas P. aeruginosa, E. coli and S. epidermidis were not internalised even after co-cultivation for 24 h. These data suggest that the suitability of a bacterial food source for the Acanthamoeba spp. studied is associated not only with the proclivity with which the bacterial species binds to the trophozoite surface, but also with the rate of its internalisation.

Loofah sponges as reservoirs and vehicles in the transmission of potentially pathogenic bacterial species to human skin

Loofah sponges are natural products used as exfoliative beauty aids. As a consequence of tracing a case of Pseudomonas aeruginosa folliculitis to a contaminated loofah sponge, we assessed the role of loofah sponges in supporting the growth of a wide variety of bacterial species. Our data show growth enhancement of sterile loofah fragments for numerous gram-negative (Pseudomonas, Xanthomonas, and Klebsiella) and gram-positive (Enterococcus and group B Streptococcus) species of human and environmental origin. Furthermore, hydrated new, unused loofah sponges undergo a shift in bacterial flora from sparse colonies of Bacillus spp. and Staphylococcus epidermidis to a predominantly gram-negative flora. The growth-promoting potential of loofah sponges (and other exfoliatives) can be further augmented by desquamated epithelial cells entrapped in the loofah fibrous matrix. Therefore, as loofah sponges (and other exfoliatives) can serve as a reservoir and a vehicle for the transmission of potentially pathogenic species to the human skin, we recommend their decontamination with hypochlorite (10%) bleach at regular intervals.

Inhibition of Acanthamoeba species by Pseudomonas aeruginosa: rationale for their selective exclusion in corneal ulcers and contact lens care systems

Cocultivation of Acanthamoeba castellanii and Acanthamoeba polyphaga with live Pseudomonas aeruginosa and with broth filtrates of P. aeruginosa proved equally lethal to the Acanthamoeba spp. The P. aeruginosa-induced amebicidal activity is apparently toxin mediated and has two operative modes: it can function through binding of P. aeruginosa to the ameba membrane and in the presence of one or more P. aeruginosa exoproducts.

Pseudomonas aeruginosa folliculitis acquired through use of a contaminated loofah sponge: an unrecognized potential public health problem

Pseudomonas aeruginosa folliculitis is a well-known entity that occurs among users of closed-cycle recreational water sources such as whirlpools, swimming pools, and hot tubs. In the absence of this epidemiologic link, isolated cases are difficult to diagnose. We encountered a patient who developed P. aeruginosa folliculitis subsequent to the use of a loofah sponge grossly contaminated with the same P. aeruginosa strain (serotype 10; pyocin type 1/a 4,b) that was recovered from her skin lesions. Furthermore, we demonstrated that sterile unused loofah sponges can serve as the sole growth-promoting substrate for P. aeruginosa. To obviate the potential public health problem of contaminated loofah sponges, it is strongly recommended that manufacturers append, and consumers adhere to, instructions as to the care of loofah sponges, which includes allowing the sponge to dry after use.

Tumor control in definitive irradiation of localized carcinoma of the prostate

At the Mallinckrodt Institute of Radiology, Washington University, 343 patients with carcinoma of the prostate were treated with definitive radiotherapy. All patients are available for minimal 3 year follow-up; the median period of observation is 5.2 years. The incidence of pelvic recurrence with or without distant metastases was 0% in 10 patients with Stage A2, 11% in 113 patients with Stage B, 34% in 204 patients with Stage C, and 40% in 16 patients with Stage D1. There was no significant difference in pelvic tumor control when correlated with the degree of differentiation of the tumors in each stage. In Stage B, patients who exhibited complete regression 3 months after completion of therapy had a pelvic failure rate of 5%, those with 50-75% regression-8% and less than 50% regression-18%. In Stage C, patients with more than 50% tumor regression had a pelvic failure rate of 25%, in contrast to 37% when less than 50% regression was noted at 3 months after completion of irradiation. However, there was no correlation between tumor regression and NED survival. In patients with Stage B, there was no significant correlation between doses of irradiation ranging from 6000 to 7000 cGy and pelvic tumor control. In Stage C, patients receiving doses higher than 6500 cGy had a probability of failure rate in the pelvis of 25% (40/173), in comparison with 44% with doses between 6000-6500 cGy (15/32). The 10 year NED survival for Stage A2 was 100%, Stage B-70%, and Stage C-40%. In Stage B, there was no correlation between local tumor control and 5 year overall survival. However, at 10 years 88 patients without evidence of local failure or distant metastases had a survival rate of 70% in contrast to only 25% if they recurred. In Stage C, 110 patients without local recurrence or distant metastases had a 40% 10 year survival in contrast to 20% in 55 patients who had pelvic recurrence (with or without distant metastases) and 39 patients with distant metastases only. In 105 patients with Stage B tumor controlled in the pelvis, the incidence of distant metastases was 16%, in contrast to 50% in eight patients with pelvic failure. In Stage C, only 26% of 149 patients with pelvic tumor controlled developed distant disease, versus 60% in 55 patients failing in the pelvis. Ninety-five percent of the pelvic failures and 80% of the distant metastases appeared within 5 years after therapy. The administration of hormones did not significantly influence either the probability of pelvic tumor control or the appearance of distant metastases.

Detection of endotoxin in cerebrospinal and joint fluids by limulus assay

Cerebrospinal fluid (CSF) and joint fluid from 81 patients were studied for the presence of endotoxin using the limulus assay. All fluids that grew Gram-negative organisms had a positive limulus test. However, one sample of CSF and one of joint fluid, both very purulent, that contained Gram-positive organisms also gave positive limulus assays. All culturally negative fluids had a negative limulus assay. Thus, a positive limulus assay with CSF or joint fluid is indicative of bacterial infection probably caused by Gram-negative organisms and can be an extremely useful diagnostic adjunct.