Reputation based on punishment rather than generosity allows for evolution of cooperation in sizable groups

Cooperation among unrelated individuals can arise if decisions to help others can be based on reputation. While working for dyadic interactions, reputation-use in social dilemmas involving many individuals (e.g. public goods games) becomes increasingly difficult as groups become larger and errors more frequent. Reputation is therefore believed to have played a minor role for the evolution of cooperation in collective action dilemmas such as those faced by early humans. Here, we show in computer simulations that a reputation system based on punitive actions can overcome these problems and, compared to reputation system based on generous actions, (i) is more likely to lead to the evolution of cooperation in sizable groups, (ii) more effectively sustains cooperation within larger groups, and (iii) is more robust to errors in reputation assessment. Punishment and punishment reputation could therefore have played crucial roles in the evolution of cooperation within larger groups of humans.

Determination of bacterial quantity by sonication in vacum-assisted closure (VAC) foams used for treatment of chronic wounds

Background: Negative pressure wound treatment is increasingly used through a Vacuum-Assisted Closure (VAC) device in complex wound situations. For this purpose, sterile polyurethane (PU) and polyvinyl alcohol (PVA) foam dressings are fitted to the wound size and covered with an adhesive drape to create an airtight seal. Little information exists about the type and quantity of microorganisms within the foams. Therefore, we investigated VAC foams after removal from the wound using a validated method (sonication) to detect the bacterial bioburden in the foam consisting as microbial biofilms.Methods: We prospectively included VAC foams (PU and PVA, KCI, Rümlamg, Switzerland) without antibacterial additions (e.g. silver), which were removed from wounds in patients with chronic ulcers from January 2007 through December 2008. Excluded were patients with acute wound infection, necrotizing fasciitis, underlying osteomyelitis or implant. Removed foams from regular changes of dressing were aseptically placed in a container with 100 ml sterile Ringer's solution. Within 4 hours after removal, foams were sonicated for 5 min at 40 kHz (as described in NEJM 2007;357:654). The resulting sonication fluid was cultured at 37°C on aerobic blood agar plates for 5 days. Microbes were quantified as No. of colony-forming units (CFU)/ml sonication fluid and identified to the species level.Results: A total of 68 foams (38 PU and 30 PVA) from 55 patients were included in the study (median age 71 years; range 33-88 years, 57% were man). Foams were removed from the following anatomic sites: sacrum (n=29), ischium (n=18), heel (n=13), calves (n=6) and ankle (n=2). The median duration of being in place was 3 days (range, 1-8 days). In all 68 foams, bacteria were found in large quantities (median 105 CFU/ml, range 102-7 CFU/ml sonication fluid. No differences were found between PU and PVA foams. One type of organisms was found in 11 (16%), two in 17 (24%) and 3 or more in 40 (60%) foams. Gram-negative rods (Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Acinetobacter baumanii, Pseudomonas aeruginosa) were isolated in 70%, followed by Staphylococcus aureus (20%), koagulase-negative staphylococci, streptococci (8%), and enterococci (2%).Conclusion: With sonication, a high density of bacteria present in VAC foams was demonstrated after a median of 3 days. Future studies are needed to investigate whether antimicrobial-impregnated foams can reduce the bacterial load in foams and potentially improve wound healing.

Procalcitonin for reduced antibiotic exposure in ventilator-associated pneumonia: a randomised study.

In patients with ventilator-associated pneumonia (VAP), guidelines recommend antibiotic therapy adjustment according to microbiology results after 72 h. Circulating procalcitonin levels may provide evidence that facilitates the reduction of antibiotic therapy. In a multicentre, randomised, controlled trial, 101 patients with VAP were assigned to an antibiotic discontinuation strategy according to guidelines (control group) or to serum procalcitonin concentrations (procalcitonin group) with an antibiotic regimen selected by the treating physician. The primary end-point was antibiotic-free days alive assessed 28 days after VAP onset and analysed on an intent-to-treat basis. Procalcitonin determination significantly increased the number of antibiotic free-days alive 28 days after VAP onset (13 (2-21) days versus 9.5 (1.5-17) days). This translated into a reduction in the overall duration of antibiotic therapy of 27% in the procalcitonin group (p = 0.038). After adjustment for age, microbiology and centre effect, the rate of antibiotic discontinuation on day 28 remained higher in the procalcitonin group compared with patients treated according to guidelines (hazard rate 1.6, 95% CI 1.02-2.71). The number of mechanical ventilation-free days alive, intensive care unit-free days alive, length of hospital stay and mortality rate on day 28 for the two groups were similar. Serum procalcitonin reduces antibiotic therapy exposure in patients with ventilator associated pneumonia.

Weak and Strong Altruism in Trait Groups: Reproductive Suicide, Personal Fitness, and Expected Value

A simple variant of trait group selection, employing predators as the mechanism underlying group selection, supports contingent reproductive suicide as altruism (i.e., behavior lowering personal fitness while augmenting that of another) without kin assortment. The contingent suicidal type may either saturate the population or be polymorphic with a type avoiding suicide, depending on parameters. In addition to contingent suicide, this randomly assorting morph may also exhibit continuously expressed strong altruism (sensu Wilson 1979) usually thought restricted to kin selection. The model will not, however, support a sterile worker caste as such, where sterility occurs before life history events associated with effective altruism; reproductive suicide must remain fundamentally contingent (facultative sensu West Eberhard 1987; Myles 1988) under random assortment. The continuously expressed strong altruism supported by the model may be reinterpreted as probability of arbitrarily committing reproductive suicide, without benefit for another; such arbitrary suicide (a "load" on "adaptive" suicide) is viable only under a more restricted parameter space relative to the necessarily concomitant adaptive contingent suicide.

The prevalence and management of cardiovascular risk factors in immigrant groups in Switzerland.

OBJECTIVES: To compare the prevalence and management of cardiovascular risk factors (CVRFs) between immigrant groups and Swiss nationals. METHODS: The Swiss Health Surveys (SHS, N = 49,245) and CoLaus study (N = 6,710) were used. Immigrant groups from France, Germany, Italy, Portugal, Spain, former Yugoslavia, other European and other countries were defined. RESULTS: Immigrants from Italy, France, Portugal, Spain and former Yugoslavia presented a higher prevalence of smoking than Swiss nationals. Immigrants reported less hypertension than Swiss nationals, but the differences were reduced when blood pressure measurements were used. The prevalence of dyslipidaemia was similar between immigrants and Swiss nationals in the SHS. When eligibility for statin treatment was assessed, immigrants from Italy were more frequently eligible than Swiss nationals. Immigrants from former Yugoslavia presented a lower prevalence of diabetes in the SHS, but a higher prevalence in the CoLaus study. Most differences between immigrant groups and Swiss nationals disappeared after adjusting for age, leisure-time physical activity, being overweight/obesity and education. CONCLUSIONS: Most CVRFs are unevenly distributed among immigrant groups in Switzerland, but these differences are due to disparities in age, leisure-time physical activity, being overweight/obesity and education.

APPROACH AND TREATMENT OF SUICIDAL BEHAVIOR IN THE CLINICAL PRACTICE OF DIFFERENT GROUPS OF HEALTH PROFESSIONALS IN SPAIN: RESULTS OF THE PROJECT EUREGENA.

According to the WHO (World Health Organization) and the European Union, suicide is considered to be a health problem of prime importance and to be one of the principal causes of unnatural death. In Spain, the number of suicides has increased 12% since 2005 . The Research Project “European Regions Enforcing Actions against Suicide (EUREGENAS), funded by the Health Program 2008-2013, has as main objective the description of an integrated model of Mental Health orientated to the prevention of suicide. The differences that allow distinguishing the meaning of prevention in suicide behavior are described and explained through a qualitative methodological strategy and through the creation of discussion groups formed by different groups of health professionals. The results highlight the existing differences between the diverse health professionals who come more in contact with this problem and it shows as well the coincidence of meaning that suicide has to be considered as a priority in the field of health.

Iowa's Water - Ambient Monitoring Program: Bacterial Monitoring of Iowa's Beaches, January 2001

The Iowa Department of Natural Resources has produced an 4 page article about how to assess Iowa's streams and rivers. How to use ambient monitoring of streams and river in Iowa.

Natural variability of in vitro adherence to fibrinogen and fibronectin does not correlate with in vivo infectivity of Staphylococcus aureus.

Adherence to fibrinogen and fibronectin plays a crucial role in Staphylococcus aureus experimental endocarditis. Previous genetic studies have shown that infection and carriage isolates do not systematically differ in their virulence-related genes, including genes conferring adherence, such as clfA and fnbA. We set out to determine the range of adherence phenotypes in carriage isolates of S. aureus, to compare the adherence of these isolates to the adherence of infection isolates, and to determine the relationship between adherence and infectivity in a rat model of experimental endocarditis. A total of 133 healthy carriage isolates were screened for in vitro adherence to fibrinogen and fibronectin, and 30 isolates were randomly chosen for further investigation. These 30 isolates were compared to 30 infective endocarditis isolates and 30 blood culture isolates. The infectivities of the carriage isolates, which displayed either extremely low or high adherence to fibrinogen and fibronectin, were tested using a rat model of experimental endocarditis. The levels of adherence to both fibrinogen and fibronectin were very similar for isolates from healthy carriers and members of the two groups of infection isolates. All three groups of isolates showed a wide range of adherence to fibrinogen and fibronectin. Moreover, the carriage isolates that showed minimal adherence and the carriage isolates that showed strong adherence had the same infectivity in experimental endocarditis. Adherence was proven to be important for pathogenesis in experimental endocarditis, but even the least adherent carriage strains had the ability to induce infection. We discuss the roles of differential gene expression, human host factors, and gene redundancy in resolving this apparent paradox.

Hemoglobin enhances the biological activity of synthetic and natural bacterial (endotoxic) virulence factors: a general principle.

Although hemoglobin (Hb) is mainly present in the cytoplasm of erythrocytes (red blood cells), lower concentrations of pure, cell-free Hb are released permanently into the circulation due to an inherent intravascular hemolytic disruption of erythrocytes. Previously it was shown that the interaction of Hb with bacterial endotoxins (lipopolysaccharides, LPS) results in a significant increase of the biological activity of LPS. There is clear evidence that the enhancement of the biological activity of LPS by Hb is connected with a disaggregation of LPS. From these findings one questions whether the property to enhance the biological activity of endotoxin, in most cases proven by the ability to increase the cytokine (tumor-necrosis-factor-alpha, interleukins) production in human mononuclear cells, is restricted to bacterial endotoxin or is a more general principle in nature. To elucidate this question, we investigated the interaction of various synthetic and natural virulence (pathogenicity) factors with hemoglobin of human or sheep origin. In addition to enterobacterial R-type LPS a synthetic bacterial lipopeptide and synthetic phospholipid-like structures mimicking the lipid A portion of LPS were analysed. Furthermore, we also tested endotoxically inactive LPS and lipid A compounds such as those from Chlamydia trachomatis. We found that the observations made for endotoxically active form of LPS can be generalized for the other synthetic and natural virulence factors: In every case, the cytokine-production induced by them is increased by the addition of Hb. This biological property of Hb is connected with its physical property to convert the aggregate structures of the virulence factors into one with cubic symmetry, accompanied with a considerable reduction of the size and number of the original aggregates.

Improving Transition Outcomes: Council Bluffs Youth Connections Prototype: Barriers Identified Through the Focus Groups and Interviews

Information gleaned from the focus groups and individual interviews with educators, youth and parents.

Value of sTREM-1, procalcitonin and CRP as laboratory parameters for postmortem diagnosis of sepsis.

OBJECTIVES: Triggering receptor expressed on myeloid cells-1 (TREM-1) was reported to be up-regulated in various inflammatory diseases as well as in bacterial sepsis. Increased cell-surface TREM-1 expression was also shown to result in marked plasma elevation of the soluble form of this molecule (sTREM-1) in patients with bacterial infections. In this study, we investigated sTREM-1, procalcitonin and C-reactive protein in postmortem serum in a series of sepsis-related fatalities and control individuals who underwent medico-legal investigations. sTREM-1 was also measured in pericardial fluid and urine. METHODS: Two study groups were prospectively formed, a sepsis-related fatalities group and a control group. The sepsis-related fatalities group consisted of sixteen forensic autopsy cases. Eight of these had a documented clinical diagnosis of sepsis in vivo. The control group consisted of sixteen forensic autopsy cases with various causes of death. RESULTS: Postmortem serum sTREM-1 concentrations were higher in the sepsis group with a mean value of 173.6 pg/ml in septic cases and 79.2 pg/ml in control individuals. The cutoff value of 90 pg/ml provided the best sensitivity and specificity. Pericardial fluid sTREM-1 values were higher in the septic group, with a mean value of 296.7 pg/ml in septic cases and 100.9 pg/ml in control individuals. The cutoff value of 135 pg/ml provided the best sensitivity and specificity. Mean urine sTREM-1 concentration was 102.9 pg/ml in septic cases and 89.3 pg/ml in control individuals. CONCLUSIONS: Postmortem serum sTREM-1, individually considered, did not provide better sensitivity and specificity than procalcitonin in detecting sepsis. However, simultaneous assessment of procalcitonin and sTREM-1 in postmortem serum can be of help in clarifying contradictory postmortem findings. sTREM-1 determination in pericardial fluid can be an alternative to postmortem serum in those situations in which biochemical analyses are required and blood collected during autopsy proves insufficient.

The so-called 'external partners' in the groups of corporations: A model of presentation in the consolidated statements

This paper studies, on the one hand, theories set out around theconsideration of the external partners in the consolidated informationand on the other hand, financial models that discuss the convenience ofthe separation or not of the different elements that form part of theliabilities of the balance sheet of the companies. A Model is proposed,the External Partners Model, which financially argues a certain presentationand processing of such and that, in our opinion, facilitates the analysisof the consolidated financial statements. This model is based on twohypotheses: (1) the economic and financial variables are not independentand (2) the value of the company depends, among other factors, of thetype of sources that constitute their capital. These two hypotheses willimply that a separation should be included in the consolidated balance sheet between equity and liabilities as they are different sources ofcapital and then its separation will give relevant information to itsusers.

Protection from lethal gram-negative bacterial sepsis by targeting Toll-like receptor 4.

Toll-like receptor 4 (TLR4), the signal-transducing molecule of the LPS receptor complex, plays a fundamental role in the sensing of LPS from gram-negative bacteria. Activation of TLR4 signaling pathways by LPS is a critical upstream event in the pathogenesis of gram-negative sepsis, making TLR4 an attractive target for novel antisepsis therapy. To validate the concept of TLR4-targeted treatment strategies in gram-negative sepsis, we first showed that TLR4(-/-) and myeloid differentiation primary response gene 88 (MyD88)(-/-) mice were fully resistant to Escherichia coli-induced septic shock, whereas TLR2(-/-) and wild-type mice rapidly died of fulminant sepsis. Neutralizing anti-TLR4 antibodies were then generated using a soluble chimeric fusion protein composed of the N-terminal domain of mouse TLR4 (amino acids 1-334) and the Fc portion of human IgG1. Anti-TLR4 antibodies inhibited intracellular signaling, markedly reduced cytokine production, and protected mice from lethal endotoxic shock and E. coli sepsis when administered in a prophylactic and therapeutic manner up to 13 h after the onset of bacterial sepsis. These experimental data provide strong support for the concept of TLR4-targeted therapy for gram-negative sepsis.