Role of Activity in Human Dynamics

The human society is a very complex system; still, there are several non-trivial, general features. One type of them is the presence of power-law distributed quantities in temporal statistics. In this Letter, we focus on the origin of power-laws in rating of movies. We present a systematic empirical exploration of the time between two consecutive ratings of movies (the interevent time). At an aggregate level, we find a monotonous relation between the activity of individuals and the power-law exponent of the interevent-time distribution. At an individual level, we observe a heavy-tailed distribution for each user, as well as a negative correlation between the activity and the width of the distribution. We support these findings by a similar data set from mobile phone text-message communication. Our results demonstrate a significant role of the activity of individuals on the society-level patterns of human behavior. We believe this is a common character in the interest-driven human dynamics, corresponding to (but different from) the universality classes of task-driven dynamics.Comment: 5 pages, 6 figures. Accepted by EP

Guidance toward the implementation of multicriteria decision analysis framework in developing countries.

Introduction: Multiple Criteria Decision Analysis (MCDA) is increasingly used in health care mainly because it moves decision-making from ad hoc to an evidence-based and comprehensive process. Developing countries with more restricted financial and human research capacities, however, should consider their own methods of MCDA development and implementation. Areas covered: An MCDA framework to improve procurement decisions of off-patent pharmaceuticals was developed for developing countries and adapted to Indonesia, Kazakhstan and Vietnam during three policy workshops. Based on the experience of these workshops and one joint workshop with international experts and decision makers from multiple developing countries, general recommendations were formulated on how to implement MCDA specifically in developing countries. We provide 17 practical MCDA implementation recommendations in four major areas, including (1) MCDA objectives; (2) technical considerations of MCDA tool; (3) development and customization of MCDA tool and (4) policy implementation of MCDA in decision-making. Expert commentary: These practical MCDA recommendations for developing countries contribute to feasible, transparent, stepwise, iterative and standardized decision-making in health care.</br

Assessing antimicrobial misuse in small-scale chicken farms in Vietnam from an observational study

BACKGROUND: Antimicrobials are used by poultry farmers in Vietnam as a tool to treat and prevent infectious diseases. We aimed to determine the fraction of disease episodes likely to remain untreated due to the administration of antimicrobials on non-susceptible pathogens in chicken flocks in the Mekong Delta of Vietnam. Weekly data on antimicrobial use and clinical signs were collected from 88 randomly chosen chicken flocks over 124 full production cycles (i.e. time between restocking flocks with day-old chicks and sale for slaughter). A naïve Bayes model was trained to infer the probabilities of disease episodes having been caused by each of 24 pathogens, given the observed clinical sign profile, and expert knowledge on their relative incidence. RESULTS: A total of 224 disease episodes were observed, of which 44.8% were attributed to viruses (95% CI 31.1-58.4%), 54.6% (CI 40.4-68.7%) to bacteria, and 0.6% (CI 0-1.7%) to a protozoan (Eimeria spp.). Antimicrobials were more frequently administered on weeks with disease than on weeks without disease (43.3% vs. 17.8%; p &lt; 0.001). A median of 2 [IQR 0-4] antimicrobials were used by episode. The choice of specific antimicrobials was independent on whether the flocks had disease clinical signs or not. Antimicrobials were not used in 30.3% of the episodes. The overall probability that episodes were not effectively treated was 74.2, and 53.7% when discounting cases where the inferred aetiology is viral. Considering only episodes where antimicrobials were given, these probabilities were 57.4 and 23.8% respectively. CONCLUSIONS: This study highlights untargeted use of antimicrobials on small-scale Vietnamese chicken farms, as well as the limitations of antimicrobials as effective tools to control infectious diseases

Facile Synthesis of 4-Oxo-4<i>H</i>-quinolizine-2-carboxamide Derivatives

<div><p></p><p>A facile synthetic method for the construction of 2-substituted-4-oxo-4H-quinolizine based core structure has been successfully developed. The synthesis made use of a one pot Stobbe condensation followed by cyclisation starting from the commercially available 2-pyridinecarbaldehyde. The structure of the formed 4-oxo-4H-quinolizine-2-carboxylate was fully confirmed by MS, ¹H NMR, ¹³C NMR, COSY, HMBC and HSQC spectra. The ethyl carboxylate moiety was then further functionalized via direct aminolysis by a range of amines to afford the corresponding 4-oxo-4H-quinolizine-2-carboxamides <b>4a-i</b> in moderate to good yields.</p></div

A survey of retail prices of antimicrobial products used in small-scale chicken farms in the Mekong Delta of Vietnam.

BACKGROUND:In the Mekong Delta region of Vietnam, high quantities of products containing antimicrobial are used as prophylactic and curative treatments in small-scale chicken flocks. A large number of these contain antimicrobial active ingredients (AAIs) considered of 'critical importance' for human medicine according to the World Health Organization (WHO). However, little is known about the retail prices of these products and variables associated with the expense on antimicrobials at farm level. Therefore, the aims of the study were: (1) to investigate the retail price of antimicrobials with regards to WHO importance criteria; and (2) to quantify the antimicrobial expense incurred in raising chicken flocks. We investigated 102 randomly-selected small-scale farms raising meat chickens (100-2000 per flock cycle) in two districts in Dong Thap (Mekong Delta) over 203 flock production cycles raised in these farms. Farmers were asked to record the retail prices and amounts of antimicrobial used. RESULTS:A total of 214 different antimicrobial-containing products were identified. These contained 37 different AAIs belonging to 13 classes. Over half (60.3%) products contained 1 highest priority, critically important AAI, and 38.8% 1 high priority, critically important AAI. The average (farm-adjusted) retail price of a daily dose administered to a 1 kg bird across products was 0.40 cents of 1 US$ (₵) (SE ± 0.05). The most expensive products were those that included at least one high priority, critically important AAI, as well as those purchased in one of the two study districts. Farmers spent on average of ₵3.91 (SE ± 0.01) on antimicrobials per bird over the production cycle. The expense on antimicrobials in weeks with disease and low mortality was greater than on weeks with disease and high mortality, suggesting that antimicrobial use had a beneficial impact on disease outcomes (χ2 = 3.8; p = 0.052). Farmers generally used more expensive antimicrobials on older flocks. CONCLUSIONS AND RECOMMENDATION:The retail prices of antimicrobial products used in chicken production in Mekong Delta small-scale chicken farms are very low, and not related to their relevance for human medicine. Farmers, however, demonstrated a degree of sensitivity to prices of antimicrobial products. Therefore, revising pricing policies of antimicrobial products remains a potential option to curb the use of antimicrobials of critical importance in animal production