An experimental analysis of design choices of multi-objective ant colony optimization algorithms

There have been several proposals on how to apply the ant colony optimization (ACO) metaheuristic to multi-objective combinatorial optimization problems (MOCOPs). This paper proposes a new formulation of these multi-objective ant colony optimization (MOACO) algorithms. This formulation is based on adding specific algorithm components for tackling multiple objectives to the basic ACO metaheuristic. Examples of these components are how to represent multiple objectives using pheromone and heuristic information, how to select the best solutions for updating the pheromone information, and how to define and use weights to aggregate the different objectives. This formulation reveals more similarities than previously thought in the design choices made in existing MOACO algorithms. The main contribution of this paper is an experimental analysis of how particular design choices affect the quality and the shape of the Pareto front approximations generated by each MOACO algorithm. This study provides general guidelines to understand how MOACO algorithms work, and how to improve their design.     

The role of procalcitonin in neonatal intensive care unit patients with candidemia

Candidemia is a major infectious complication in neonatal patients. The isolation of yeasts from blood is still the ??gold standard?? for its diagnosis, but other laboratory markers (i.e., circulating antigens) have been studied with varying specificities and sensitivities. The aim of this study was to evaluate the role of procalcitonin for the diagnosis of candidemia in neonatal patients at high risk. To verify if the use of different commercial methods can highlight dissimilar results of sensitivity and/or specificity, the determination of procalcitonin serum levels was estimated by two systems. Overall, 90 patients from a Neonatal Intensive Care Units were enrolled, of whom six developed Candida bloodstream infection. Four of six infants with candidemia had slight increase of procalcitonin values (0.5?C1?ng/mL). Only one baby showed very high levels but he had fungal and bacterial sepsis at the same time, while no elevation was observed in the sixth patient. No statistically significant difference was observed between two different methods at the time of monitoring (p?>?0.643). Both methods showed a sensitivity of 83.3?% at diagnosis, while the specificity was 73.8 and 63.1?% by methods A and B, respectively. In the light of the low sensibility and specificity of this assay, we can assume that the determination of procalcitonin would not seem to play a significant role in the diagnosis of fungal infection in neonatal patients.     

Congenital cutaneous candidiasis associated with maternal peripartum candidemia

BackgroundCutaneous congenital candidiasis (CCC) is a rare condition consisting of invasive fungal infection of the epidermis and dermis that mostly affects preterm infants. Maternal vaginal candidiasis is present in half of the cases, although the occurrence of invasive candidiasis during pregnancy or peripartum period is exceptional.Case reportWe present the case of a full-term infant that was born by vacuum-assisted vaginal delivery to an apparently healthy 33 year-old woman with no history of intravenous drug use or vaginal candidiasis during pregnancy. The newborn showed a diffuse maculopapular rash with respiratory distress and bilateral interstitial lung infiltrates, requiring nasal continuous positive airway pressure support. Blood cultures obtained from the mother due to intrapartum fever yielded Candida albicans. Cultures of vaginal discharge and neonate skin also yielded C. albicans with the same in vitro susceptibly pattern. No alternative source for candidemia was identified. The clinical course after starting a systemic antifungal therapy was favorable in both the mother and the neonate, with clearance of candidemia and resolution of the skin lesions.ConclusionsCCC must be considered in full-term newborns with maculopapular rash at birth or during the first days of life. The absence of alternative sources for bloodstream infection in the present case suggests a potential etiopathogenic relationship between CCC and maternal candidemia. It is reasonable to rule out postpartum candidemia when CCC is suspected.     

念珠菌血症的危险因素和预后分析

目的了解念珠菌血症的临床特点、分布及预后危险因素。方法回顾性调查2012年1月至2014年5月浙江大学医学院附属第一医院所有血培养念珠菌阳性的患者资料,分析其临床特征、治疗和预后等,采用χ2检验或Fisher精确概率法进行预后单因素分析,采用多元Logistic回归进行预后多因素分析。结果 97例念珠菌血症患者入选,其中男性64例,女性33例,平均年龄（59.6±16.8）岁。包括白色念珠菌51例（52.6%）,非白色念珠菌46例（47.4%）,非白色念珠菌中热带念珠菌17例（17.5%）、近平滑念珠菌12例（12.4%）、光滑念珠菌7例（7.2%）、无名念珠菌4例（4.1%）、其他念珠菌6例（6.2%）。念珠菌培养阳性后30 d内死亡37例,30 d病死率为38.1%。Logistic多因素回归分析显示：年龄（OR=1.104,95%CI：1.041~1.170,P=0.001）、血液系统肿瘤（OR=63.256,95%CI：2.898~1380.833,P=0.008）、APACHEⅡ评分（OR=1.176,95%CI：1.053~1.313,P=0.004）、感染性休克（OR=12.032,95%CI：2.389~60.587,P=0.003）及合并细菌性血流感染（OR=26.016,95%CI：4.002~169.127,P=0.001）是其死亡的独立危险因素;而拔除或更换深静脉置管（OR=0.118,95%CI：0.025~0.559,P=0.007）是念珠菌血症死亡的独立保护性因素。结论念珠菌血症患者分布科室范围广、基础疾病重、侵入性操作多。年龄、高APACHEⅡ评分、感染性休克及合并细菌血流感染是影响念珠菌血症死亡的独立危险因素,拔除或更换深静脉置管是念珠菌血症死亡的独立保护性因素。     

The incidence of calorie labeling on fast food choices: A comparison between stated preferences and actual choices

In order to test the effect of calorie information on fast food choices, we conducted a questionnaire employing two types of stated preferences methods (the best-worst-scaling and intentional questions) and a follow-up randomized field experiment in a sample of 119 participants. This combined approach allowed us to test the internal validity of preferences for fast food meals across elicitation scenarios. The results showed that calorie information reduces the probability of selecting high calorie meals only in the questionnaire, while it did not have any significant impact on actual purchasing behavior in the field experiment. Thus, the findings show that there is a clear difference between the role of calorie information on immediate stated preference choices, and the relatively low level of responsiveness in real choices in a restaurant. We believe that the current results are quite suggestive, indicating the limits of predicting actual fast food behavior, and may open the way to using data sources that combine stated methods with field experiments.     

Sterilization: Canadian choices.

Significant differences in cost and safety between vasectomy and tubal ligation have been reported. For this reason the incidence of these two procedures between 1976 and 1986 was studied to obtain information upon which future policy decisions might be based. Although tubal ligation predominated in almost every province and year its rate declined by 27.6% over the study period, whereas the rate of vasectomy increased by 39.1%. When projected to 1988 the national rates for the two procedures became nearly equal; those for Quebec had become equal by 1986. Provincial differences were most marked in eastern Canada, where neighbouring provinces had the highest and the lowest rates of sterilization in the country. Given the relative economic and surgical disadvantages of tubal ligation, policymakers may wish to consider fostering an increased acceptance of vasectomy, particularly in areas where such acceptance continues to be slow.     

The high road and the low road: trafficking choices in plants

Polar transport of the signaling molecule auxin is critical for plant development and depends on both the polar distribution of auxin efflux carriers, which pump auxin out of the cell and the alignment of these polarized cells. Two papers in this issue of Cell (Michniewicz et al., 2007; Jaillais et al., 2007) address how polar transport of these carriers occurs and describe the endosomal pathways involved.     

The emergence of non-albicans Candida species as causes of invasive candidiasis and candidemia

The last three decades have seen an expanding pool of high-risk patients susceptible to the opportunistic pathogen Candida. Accordingly, a dramatic increase in nosocomial blood stream infections (BSIs) due to Candida spp has been reported throughout the world, starting in tertiary care centers and spreading to community hospitals. This absolute increase in Candida BSIs was accompanied by both an absolute and then a proportional increase in invasive infection caused by reduced fluconazole-susceptible non-albicans Candida spp. Currently, the incidence trend of BSI has stabilized, and Candida albicans remains the most common species causing fungal BSI. Clinicians must be aware of the importance and implications of non-albicans Candida spp when selecting antifungal drugs, although most studies have not shown significant outcome differences with use of the various antifungal classes.     

念珠菌菌血症的易感因素分析及药敏检测

目的探讨念珠菌菌血症的临床特点、菌种构成、危险因素及药敏情况,为临床治疗提供依据。方法收集我院2005年6月1日～2007年5月31日自血培养中分离出的92株念珠菌的菌种分布、药敏试验和危险因素等资料进行回顾性分析。结果菌种分布显示白念株菌感染为28.3%,除白念珠菌、光滑念珠菌、克柔念珠菌、热带念珠菌之外的其他念珠菌感染为45.6%。药敏试验显示耐氟康唑率达41.3%。感染的危险因素有免疫力低下、严重基础疾病、长时间应用广谱抗生素、介入诊治、气管切开及呼吸机的应用等,病死率超过55.4%。结论氟康唑不能作为所有酵母菌感染的首选药物。积极治疗原发病、加强病原学检测和药敏试验、及时作出早期诊断、严格掌握用药原则是降低病死率的关键。     

The weight of the self: care and compassion in Guatemalan dietary choices

The Public Health Nutrition (PHN) community categorizes dietary-related chronic illnesses as "noncommunicable," fixing these afflictions within individual bodies where they are best managed by individual choices. Yet within clinical encounters in Guatemala, nutritionists and patients treat eating and dieting as relational, transmissible practices. Patients actively seek nutritionists' care, asserting their self-care attempts have failed and they need support from others; nutritionists meanwhile develop treatment plans that situate "personal choice" as lying outside the control of a solitary individual. This article moves between international policy-pedagogy and patient-nutritionist interactions to examine forms of personhood, responsibility, and rationalities of choice present in body weight-management practices in Guatemala. Although nutrition discourses might appear to exemplify how institutional (bio)power manifests through internalized self-monitoring and preoccupation for one's own self, I argue that within the lived experiences of "nutrition-in-action," the self-body of the patient becomes broadly conceived to include the nutritionist, the family, and the broader community.     

Treating patients with low high-density lipoprotein cholesterol: choices, issues and opportunities

Three clinical trials have recently focused on the benefits of lipid-regulating therapy in populations with normocholesterolaemia and low high-density lipoprotein (HDL)-cholesterol. Two secondary prevention studies (Veterans Affairs HDL-Cholesterol Intervention Trial [VA-HIT] and Bezafibrate Infarction Prevention [BIP] trial) testified to the efficacy of fibrates in decreasing cardiovascular events, particularly in patients with coexisting risk factors, including hypertriglyceridaemia. The Air Force/Texas Coronary Atherosclerosis Prevention Study (AFCAPS/TexCAPS) demonstrated that a statin could decrease acute coronary events in patients with isolated low HDL-cholesterol in a primary prevention setting. The absolute risk reduction in coronary events in the VA-HIT study compares favourably with those reported from the statin-based Cholesterol and Recurrent Events (CARE) and Long-term Intervention with Pravastatin in Ischaemic Disease (LIPID) trials. The absolute risk reduction in AFCAPS-TexCAPS is similar to that in West of Scotland Coronary Pravastatin Study (WOSCOPS). Recommendations are given concerning lifestyle and pharmacological management of low HDL-cholesterol. Optimal management also requires review of current treatment targets for HDL-cholesterol and triglycerides levels.     

Cruel choices: autonomy and critical care decision-making

Although autonomy is clearly still the paradigm in bioethics, there is increasing concern over its value and feasibility. In agreeing with those concerns, I argue that autonomy is not just a status, but a skill, one that must be developed and maintained. I also argue that nearly all health-care interactions do anything but promote such decisional skills, since they rely upon assent, rather than upon genuinely autonomous consent. Thus, throughout most of their medical lives, patients are socialised to be heteronomous, rather than autonomous. Yet, at the worst possible time--critical care decision-making--when life and death consequences are attached to the choices, the paradigm shifts and real consent is sought, even demanded, thereby making an often traumatic situation even harder. I go on, though, to also reject paternalistic models of beneficence as an alternative. Rather, I conclude that the problem is so fundamental in healthcare that a genuine solution would require a radical restructuring. I recommend steps that can be taken in the interim to improve the situation and to move toward such a restructuring.     

The tumour necrosis factor receptor family: life or death choices

The past twelve months have seen a renewal of interest in the therapeutic potential of members of the tumour necrosis factor receptor family and their cytokine ligands. This biomedical interest has spawned a number of structural studies, which have significantly deepened our understanding of the molecular basis for the function of these cell-surface signalling systems. The fresh data have revealed unexpected mechanisms conferring ligand-receptor specificity and have highlighted the structural requirements for the initiation of intracellular signalling.