Instructor feedback versus no instructor feedback on performance in a laparoscopic virtual reality simulator: a randomized educational trial

<p>Abstract</p> <p>Background</p> <p>Several studies have found a positive effect on the learning curve as well as the improvement of basic psychomotor skills in the operating room after virtual reality training. Despite this, the majority of surgical and gynecological departments encounter hurdles when implementing this form of training. This is mainly due to lack of knowledge concerning the time and human resources needed to train novice surgeons to an adequate level. The purpose of this trial is to investigate the impact of instructor feedback regarding time, repetitions and self-perception when training complex operational tasks on a virtual reality simulator.</p> <p>Methods/Design</p> <p>The study population consists of medical students on their 4^thto 6^thyear without prior laparoscopic experience. The study is conducted in a skills laboratory at a centralized university hospital. Based on a sample size estimation 98 participants will be randomized to an intervention group or a control group. Both groups have to achieve a predefined proficiency level when conducting a laparoscopic salpingectomy using a surgical virtual reality simulator. The intervention group receives standardized instructor feedback of 10 to 12 min a maximum of three times. The control group receives no instructor feedback. Both groups receive the automated feedback generated by the virtual reality simulator. The study follows the CONSORT Statement for randomized trials. Main outcome measures are time and repetitions to reach the predefined proficiency level on the simulator. We include focus on potential sex differences, computer gaming experience and self-perception.</p> <p>Discussion</p> <p>The findings will contribute to a better understanding of optimal training methods in surgical education.</p> <p>Trial Registration</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT01497782">NCT01497782</a></p

Retracting and seeking movements during laparoscopic goal-oriented movements. Is the shortest path length optimal?

Aims- Minimally invasive surgery (MIS) requires a high degree of eye–hand coordination from the surgeon. To facilitate the learning process, objective assessment systems based on analysis of the instruments’ motion are being developed. To investigate the influence of performance on motion characteristics, we examined goaloriented movements in a box trainer. In general, goal-oriented movements consist of a retracting and a seeking phase, and are, however, not performed via the shortest path length. Therefore, we hypothesized that the shortest path is not an optimal concept in MIS. Methods-Participants were divided into three groups (experts, residents, and novices). Each participant performed a number of one-hand positioning tasks in a box trainer. Movements of the instrument were recorded with the TrEndo tracking system. The movement from point A to B was divided into two phases: A-M (retracting) and M-B (seeking). Normalized path lengths (given in %) of the two phases were compared. Results- Thirty eight participants contributed. For the retracting phase, we found no significant difference between experts [median (range) %: 152 (129–178)], residents [164 (126–250)], and novices [168 (136–268)]. In the seeking phase, we find a significant difference (<0.001) between experts [180 (172–247)], residents [201 (163–287)], and novices [290 (244–469)]. Moreover, within each group, a significant difference between retracting and seeking phases was observed. Conclusions- Goal-oriented movements in MIS can be split into two phases: retracting and seeking. Novices are less effective than experts and residents in the seeking phase. Therefore, the seeking phase is characteristic of performance differences. Furthermore, the retracting phase is essential, because it improves safety by avoiding intermediate tissue contact. Therefore, the shortest path length, as presently used during the assessment of basic MIS skills, may be not a proper concept for analyzing optimal movements and, therefore, needs to be revised.Biomechanical EngineeringMechanical, Maritime and Materials Engineerin

Making Associativity Operational

The purpose of this paper is to propose an operational idea for developing algebraic thinking in the absence of alphanumeric symbols. The paper reports on a design experiment encouraging preschool children to use the associative property algebraically. We describe the theoretical basis of the design, the tasks used, and examples of algebraic thinking in 5–6-year-old children. Theoretically, the paper makes a critical distinction between operational and structural meanings of the notion of equality. We argue that mathematical thinking involving equality among young learners can comprise both an operational and a structural conception and that the operational conception has a side that is productively linked to the structural conception. Using carefully designed hands-on tasks, the crux of the paper is the realization of algebraic thinking (in verbal mathematics) as operationally experienced in the ability to transform one number structure, with a quantity that is subject to change, into another through equality-preserving transformations

Low pH immobilizes and kills human leukocytes and prevents transmission of cell-associated HIV in a mouse model

BACKGROUND: Both cell-associated and cell-free HIV virions are present in semen and cervical secretions of HIV-infected individuals. Thus, topical microbicides may need to inactivate both cell-associated and cell-free HIV to prevent sexual transmission of HIV/AIDS. To determine if the mild acidity of the healthy vagina and acid buffering microbicides would prevent transmission by HIV-infected leukocytes, we measured the effect of pH on leukocyte motility, viability and intracellular pH and tested the ability of an acidic buffering microbicide (BufferGel(®)) to prevent the transmission of cell-associated HIV in a HuPBL-SCID mouse model. METHODS: Human lymphocyte, monocyte, and macrophage motilities were measured as a function of time and pH using various acidifying agents. Lymphocyte and macrophage motilities were measured using video microscopy. Monocyte motility was measured using video microscopy and chemotactic chambers. Peripheral blood mononuclear cell (PBMC) viability and intracellular pH were determined as a function of time and pH using fluorescent dyes. HuPBL-SCID mice were pretreated with BufferGel, saline, or a control gel and challenged with HIV-1-infected human PBMCs. RESULTS: Progressive motility was completely abolished in all cell types between pH 5.5 and 6.0. Concomitantly, at and below pH 5.5, the intracellular pH of PBMCs dropped precipitously to match the extracellular medium and did not recover. After acidification with hydrochloric acid to pH 4.5 for 60 min, although completely immotile, 58% of PBMCs excluded ethidium homodimer-1 (dead-cell dye). In contrast, when acidified to this pH with BufferGel, a microbicide designed to maintain vaginal acidity in the presence of semen, only 4% excluded dye at 10 min and none excluded dye after 30 min. BufferGel significantly reduced transmission of HIV-1 in HuPBL-SCID mice (1 of 12 infected) compared to saline (12 of 12 infected) and a control gel (5 of 7 infected). CONCLUSION: These results suggest that physiologic or microbicide-induced acid immobilization and killing of infected white blood cells may be effective in preventing sexual transmission of cell-associated HIV

Household Possession and Use of Insecticide-Treated Mosquito Nets in Sierra Leone 6 Months after a National Mass-Distribution Campaign

BACKGROUND: In November 2010, Sierra Leone distributed over three million long-lasting insecticide-treated nets (LLINs) with the objective of providing protection from malaria to individuals in all households in the country. METHODS: We conducted a nationally representative survey six months after the mass distribution campaign to evaluate its impact on household insecticide-treated net (ITN) ownership and use. We examined factors associated with household ITN possession and use with logistic regression models. RESULTS: The survey included 4,620 households with equal representation in each of the 14 districts. Six months after the campaign, 87.6% of households own at least one ITN, which represents an increase of 137% over the most recent estimate of 37% in 2008. Thirty-six percent of households possess at least one ITN per two household members; rural households were more likely than urban households to have ≥ 1:2 ITN to household members, but there was no difference by socio-economic status or household head education. Among individuals in households possessing ≥ 1 ITN, 76.5% slept under an ITN the night preceding the survey. Individuals in households where the household head had heard malaria messaging, had correct knowledge of malaria transmission, and where at least one ITN was hanging, were more likely to have slept under an ITN. CONCLUSIONS: The mass distribution campaign was effective at achieving high coverage levels across the population, notably so among rural households where the malaria burden is higher. These important gains in equitable access to malaria prevention will need to be maintained to produce long-term reductions in the malaria burden

Quantitative trait loci conferring grain mineral nutrient concentrations in durum wheat 3 wild emmer wheat RIL population

Mineral nutrient malnutrition, and particularly deficiency in zinc and iron, afflicts over 3 billion people worldwide. Wild emmer wheat, Triticum turgidum ssp. dicoccoides, genepool harbors a rich allelic repertoire for mineral nutrients in the grain. The genetic and physiological basis of grain protein, micronutrients (zinc, iron, copper and manganese) and macronutrients (calcium, magnesium, potassium, phosphorus and sulfur) concentration was studied in tetraploid wheat population of 152 recombinant inbred lines (RILs), derived from a cross between durum wheat (cv. Langdon) and wild emmer (accession G18-16). Wide genetic variation was found among the RILs for all grain minerals, with considerable transgressive effect. A total of 82 QTLs were mapped for 10 minerals with LOD score range of 3.2–16.7. Most QTLs were in favor of the wild allele (50 QTLs). Fourteen pairs of QTLs for the same trait were mapped to seemingly homoeologous positions, reflecting synteny between the A and B genomes. Significant positive correlation was found between grain protein concentration (GPC), Zn, Fe and Cu, which was supported by significant overlap between the respective QTLs, suggesting common physiological and/or genetic factors controlling the concentrations of these mineral nutrients. Few genomic regions (chromosomes 2A, 5A, 6B and 7A) were found to harbor clusters of QTLs for GPC and other nutrients. These identified QTLs may facilitate the use of wild alleles for improving grain nutritional quality of elite wheat cultivars, especially in terms of protein, Zn and Fe

Using new technologies to promote weight management: a randomised controlled trial study protocol

Background: Over the last three decades, overweight and obesity and the associated health consequences have become global public health priorities. Methods that have been tried to address this problem have not had the desired impact, suggesting that other approaches need to be considered. One of the lessons learned throughout these attempts is that permanent weight loss requires sustained dietary and lifestyle changes, yet adherence to weight management programs has often been noted as one of the biggest challenges. This trial aims to address this issue by examining whether social media, as a potential health promotion tool, will improve adherence to a weight management program. To test the effectiveness of this measure, the designated program will be delivered via the popular social networking site Facebook, and compared to a standard delivery method that provides exactly the same content but which is communicated through a pamphlet. The trial will be conducted over a period of twelve weeks, with a twelve week follow-up. Although weight loss is expected, this study will specifically investigate the effectiveness of social media as a program delivery method. The program utilised will be one that has already been proven to achieve weight loss, namely The CSIRO Total Wellbeing Diet.Methods/design: This project will be conducted as a 3-arm randomised controlled trial. One hundred and twenty participants will be recruited from the Perth community, and will be randomly assigned to one of the following three groups: the Facebook group, the pamphlet group, or a control group. The Facebook Group will receive the weight management program delivered via a closed group in Facebook, the Pamphlet Group will be given the same weight management program presented in a booklet, and the Control Group will follow the Australian Dietary Guidelines and the National Physical Activity Guidelines for Adults as usual care. Change in weight, body composition and waist circumference will be initial indicators of adherence to the program. Secondary outcome measures will be blood glucose, insulin, blood pressure, arterial stiffness, physical activity, eating behaviour, mental well-being (stress, anxiety, and depression), social support, self-control, self-efficacy, Facebook activity, and program evaluation. Discussion: It is expected that this trial will support the use of social media - a source of social support and information sharing - as a delivery method for weight management programs, enhancing the reduction in weight expected from dietary and physical activity changes. Facebook is a popular, easy to access and cost-effective online platform that can be used to assist the formation of social groups, and could be translated into health promotion practice relatively easily. It is anticipated in the context of the predicted findings that social media will provide an invaluable resource for health professionals and patients alike

Enterovirus specific anti-peptide antibodies

Enterovirus 71 (EV-71) is the main causative agent of hand, foot, and mouth disease (HFMD) which is generally regarded as a mild childhood disease. In recent years, EV71 has emerged as a significant pathogen capable of causing high mortalities and severe neurological complications in large outbreaks in Asia. A formalin-inactivated EV71 whole virus vaccine has completed phase III trial in China but is currently unavailable clinically. The high cost of manufacturing and supply problems may limit practical implementations in developing countries. Synthetic peptides representing the native primary structure of the viral immunogen which is able to elicit neutralizing antibodies can be made readily and is cost effective. However, it is necessary to conjugate short synthetic peptides to carrier proteins to enhance their immunogenicity. This review describes the production of cross-neutralizing anti-peptide antibodies in response to immunization with synthetic peptides selected from in silico analysis, generation of B-cell epitopes of EV71 conjugated to a promiscuous T-cell epitope from Poliovirus, and evaluation of the neutralizing activities of the anti-peptide antibodies. Besides neutralizing EV71 in vitro, the neutralizing antibodies were cross-reactive against several Enteroviruses including CVA16, CVB4, CVB6, and ECHO13

Mineral oil certified reference materials for the determination of polychlorinated biphenyls from the National Metrology Institute of Japan (NMIJ)

Four mineral oil certified reference materials (CRMs), NMIJ CRM 7902-a, CRM 7903-a, CRM 7904-a, and CRM 7905-a, have been issued by the National Metrology Institute of Japan, which is part of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST), for the determination of polychlorinated biphenyls (PCBs). The raw materials for the CRMs were an insulation oil (CRM 7902-a and CRM 7903-a) and a fuel oil (CRM7904-a and CRM 7905-a). A solution of PCB3, PCB8, and technical PCB products, comprising four types of Kaneclor, was added to the oil matrices. The total PCB concentrations in the PCB-fortified oils (CRM 7902-a and CRM 7904-a) are approximately 6 mg kg−1. In addition, the mineral oils which were not fortified with PCBs were also distributed as CRMs (CRM 7903-a and CRM 7905-a). Characterization of these CRMs was conducted by the NMIJ/AIST, where the mineral oils and the PCB solution were analyzed using multiple analytical methods such as dimethylsulfoxide extraction, normal-phase liquid chromatography, gel permeation chromatography, reversed-phase liquid chromatography, and chromatography using sulfoxide-bonded silica; and/or various capillary columns for gas chromatography, and two ionization modes for mass spectrometry. The target compounds in the mineral oils and those in the PCB solution were determined by one of the primary methods of measurement, isotope dilution–mass spectrometry (ID-MS). Certified values have been provided for 11 PCB congeners (PCB3, 8, 28, 52, 101, 118, 138, 153, 180, 194, and 206) in the CRMs. These CRMs have information values for PCB homologue concentrations determined by using a Japanese official method for determination of PCBs in wastes and densities determined with an oscillational density meter. Because oil samples having arbitrary PCB concentrations between respective property values of the PCB-fortified and nonfortified CRMs can be prepared by gravimetric mixing of the CRM pairs, these CRMs can be used for validation of PCB analyses using various instruments which have different sensitivities