Storing self-contained gel capillary cassettes for POC medical diagnostics

For effective clinical uptake of the lab on a chip/point of care technology (LOC-POC), in addition to cost advantages LOC-POC devices should offer multiple patient screening panels for related diseases as well as cold-chain transportation and storage abilities. We recently described a device that performs polymerase chain reaction (PCR) to simultaneously screen raw clinical samples from up to 16 patients for multiple infectious agents (Manage et al., Lab Chip, 2013, 13, 2576–2584). This cassette contains glass capillaries with desiccated semi-solid acrylamide gels that include all the reagents except for the sample, with integrated quality control. Here we report the development of protocols to store assembled PCR cassettes at room temperature, 4 uC or 220 uC as well as at +40 uC. We show that our cassettes are stable, with no loss of activity for at least 3 months at RT and at least 7 months at 4 uC and 220 uC. However, the activity of desiccated cassettes degrades when stored for more than 2 weeks at 40 uC, insufficient time for postmanufacture delivery and use of cassette PCR. To address this, we have evaluated two stage storage protocols. PCR cassettes can initially be stored at 4 uC and 220 uC for prolonged periods of time and removed for shorter term storage at RT, retaining activity for at least a month, which would facilitate transport to remote areas for testing. Effective use of cassette PCR in high temperature regions of the world, for experimental purposes defined here as 40 uC, appears to be feasible only after a first stage storage in the cold, followed by no more than 1 week at 40 uC. This should allow sufficient time for delivery by the manufacturer to a central area well served by power and refrigeration, for later ambient temperature transport and use in under-resourced areas that lack refrigeration

Transport of Fungal Symbionts by Mountain Pine Beetles

The perpetuation of symbiotic associations between bark beetles (Coleoptera: Curculionidae: Scolytinae) and ophiostomatoid fungi requires the consistent transport of fungi by successive beetle generations to new host trees. We used scanning electron microscopy and culture methods to investigate fungal transport by the mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins. MPB transports its two main fungal associates, Grosmannia clavigera (Robinson-Jeffrey and Davidson) Zipfel, de Beer and Wingfield and Ophiostoma montium (Rumbold) von Arx, in sac-like mycangia on the maxillary cardines as well as on the exoskeleton. Although spores of both species of fungi were observed on MPB exoskeletons, often in pits, O. montium spores were generally more abundant than G. clavigera spores. However, a general scarcity of spores of either species on MPB exoskeletons compared with numbers on scolytines that lack sac-like mycangia indicates that fungal transport exteriorly on MPBs is incidental rather than adaptive. Conidia were the dominant spore type transported regardless of location or species; however, our results suggest that once acquired in mycangia, conidia may reproduce in a yeast-like form and even produce hypha-like strands and compact conidiophore-like structures. Fungi that propagate in mycangia may provide beetles with a continual source of inocula during the extended egg-laying period

DETERMINING THE EFFECTIVENESS OF PROFESSIONAL TRAININGS OF TEACHERS IN A LOCAL COLLEGE

Using the quantitative research method, the effectiveness of professional trainings that have been undertaken by teachers as well as the impact on teachers’ teaching practices were determined. It likewise explored whether teachers’ assessment scores were significantly associated with their profile characteristics. The common professional trainings undertaken include in-service trainings (100%), education conferences (97.1%), informal dialogue with colleagues (97.1%), and individual or group research (91.2%). Of all the professional training activities, only getting involved with teachers on how to improve teaching practice was assessed to be highly effective in developing their competence, knowledge, and expertise. However, benchmarking visits to other colleges or universities and faculty participation in a professional organization that are helpful to their teaching profession was determined to be only moderately effective. The respondents reported significant improvements in their teaching practices in connection with content and pedagogy, diversity of learners, community linkages, and professional engagement. A positive relationship was found between the variable age and respondents’ assessment scores on benchmarking visits to other colleges or universities and individual or group research on the field of interest. However, a negative relationship exists between respondents’ highest educational attainment and assessment scores on professional links with colleagues such as mentoring, and coaching among others as part of the institutional policy. Thus, a teacher’s training that encourages collaboration and sharing of knowledge should be promoted.  Article visualizations

Development of a framework for reporting health service models for managing rheumatoid arthritis

The purpose of this study was to develop a framework for reporting health service models for managing rheumatoid arthritis (RA). We conducted a search of the health sciences literature for primary studies that described interventions which aimed to improve the implementation of health services in adults with RA. Thereafter, a nominal group consensus process was used to synthesize the evidence for the development of the reporting framework. Of the 2,033 citations screened, 68 primary studies were included which described 93 health service models for RA. The origin and meaning of the labels given to these health service delivery models varied widely and, in general, the reporting of their components lacked detail or was absent. The six dimensions underlying the framework for reporting RA health service delivery models are: (1) Why was it founded? (2) Who was involved? (3) What were the roles of those participating? (4) When were the services provided? (5) Where were the services provided/received? (6) How were the services/interventions accessed and implemented, how long was the intervention, how did individuals involved communicate, and how was the model supported/sustained? The proposed framework has the potential to facilitate knowledge exchange among clinicians, researchers, and decision makers in the area of health service delivery. Future work includes the validation of the framework with national and international stakeholders such as clinicians, health care administrators, and health services researchers

Geochemical approaches to the quantification of dispersed volcanic ash in marine sediment

Volcanic ash has long been recognized in marine sediment, and given the prevalence of oceanic and continental arc volcanism around the globe in regard to widespread transport of ash, its presence is nearly ubiquitous. However, the presence/absence of very fine-grained ash material, and identification of its composition in particular, is challenging given its broad classification as an “aluminosilicate” component in sediment. Given this challenge, many studies of ash have focused on discrete layers (that is, layers of ash that are of millimeter-to-centimeter or greater thickness, and their respective glass shards) found in sequences at a variety of locations and timescales and how to link their presence with a number of Earth processes. The ash that has been mixed into the bulk sediment, known as dispersed ash, has been relatively unstudied, yet represents a large fraction of the total ash in a given sequence. The application of a combined geochemical and statistical technique has allowed identification of this dispersed ash as part of the original ash contribution to the sediment. In this paper, we summarize the development of these geochemical/statistical techniques and provide case studies from the quantification of dispersed ash in the Caribbean Sea, equatorial Pacific Ocean, and northwest Pacific Ocean. These geochemical studies (and their sedimentological precursors of smear slides) collectively demonstrate that local and regional arc-related ash can be an important component of sedimentary sequences throughout large regions of the ocean

Latent variables and structural equation models for longitudinal relationships: an illustration in nutritional epidemiology

<p>Abstract</p> <p>Background</p> <p>The use of structural equation modeling and latent variables remains uncommon in epidemiology despite its potential usefulness. The latter was illustrated by studying cross-sectional and longitudinal relationships between eating behavior and adiposity, using four different indicators of fat mass.</p> <p>Methods</p> <p>Using data from a longitudinal community-based study, we fitted structural equation models including two latent variables (respectively baseline adiposity and adiposity change after 2 years of follow-up), each being defined, by the four following anthropometric measurement (respectively by their changes): body mass index, waist circumference, skinfold thickness and percent body fat. Latent adiposity variables were hypothesized to depend on a cognitive restraint score, calculated from answers to an eating-behavior questionnaire (TFEQ-18), either cross-sectionally or longitudinally.</p> <p>Results</p> <p>We found that high baseline adiposity was associated with a 2-year increase of the cognitive restraint score and no convincing relationship between baseline cognitive restraint and 2-year adiposity change could be established.</p> <p>Conclusions</p> <p>The latent variable modeling approach enabled presentation of synthetic results rather than separate regression models and detailed analysis of the causal effects of interest. In the general population, restrained eating appears to be an adaptive response of subjects prone to gaining weight more than as a risk factor for fat-mass increase.</p

An enclosed in-gel PCR amplification cassette with multi-target, multi-sample detection for platform molecular diagnostics

This work describes a self-contained, simple, disposable, and inexpensive gel capillary cassette for DNA amplification in near point of care settings. The cassette avoids the need for pumps or valves during raw sample delivery or polymerase chain reaction (PCR) amplification steps. The cassette contains capillary reaction units that can be stored at room temperature for up to 3 months. The current cassette configuration format can simultaneously tests up to 16 patients for two or more targets, accommodates different sample types on the same cassette, has integrated positive and negative controls and allows flexibility for multiple geometries. PCR reagents in the cassette are desiccated to allow storage at room temperature with rehydration by raw sample at the time of testing. The sample is introduced to the cassette via a transfer pipette simply by capillary force. DNA amplification was carried out in a portable prototype instrument for PCR thermal cycling with fluorescence detection of amplified products by melt curve analysis. To demonstrate performance, raw genital swabs and urine were introduced to the same cassette to simultaneously detect four sexually transmitted infections. Herpes Simplex Viruses (HSV-1 and HSV-2) were detected from raw genital swabs. Ureaplasma Urealyticum (UU) and Mycoplasma Homonis (MH) were detected from raw urine. Results for multiple patients were obtained in as little as 50'. This platform allows multiparameter clinical testing with a pre-assembled cassette that requires only the introduction of raw sample. Modification of the prototype device to accommodate larger cassettes will ultimately provide high throughput simultaneous testing of even larger numbers of samples for many different targets, as is required for most clinical applications. Combinations of wax and/or polymer cassettes holding capillary reaction units are feasible. The components of the cassette are suited to mass production and robotic assembly to produce a readily manufactured disposable reaction cassette that can be configured for disease-specific testing panels. Rapid testing with a disposable reaction cassette on an inexpensive instrument will permit on the spot evaluation of patients in the clinic for faster medical decision-making and more informed therapeutic choices

Predicting Diabetes: Clinical, Biological, and Genetic Approaches: Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR)

OBJECTIVE—To provide a simple clinical diabetes risk score and to identify characteristics that predict later diabetes using variables available in the clinic setting as well as biological variables and polymorphisms

Interakcije nekih plijesni i aflatoksinogenog soja Asspergillus flavus NRRL 3251

The objective of this study was to evaluate biotic interaction between some mould species and active producer of aflatoxin B1 Aspergillus flavus NRRL 3251, co-cultured in yeast-extract sucrose (YES) broth. Twenty-five mould strains of Alternaria spp., Cladosporium spp., Mucor spp., A. flavus and A. niger, used as biocompetitive agents, were isolated from outdoor and indoor airborne fungi, scrapings of mouldy household walls, and from stored and post-harvest maize. Aflatoxin B1 was extracted from mould biomasses with chloroform and detected using the multitoxin TLC method. The results confirm antagonistic interaction between all strains tested. With Alternaria spp. and Cladosporium spp., aflatoxin B1 production decreased 100 %, compared to detection in a single culture of A. flavus NRRL 3251 (Cmean=18.7 µg mL-1). In mixed cultures with Mucor spp., aflatoxin B1 levels dropped to (5.6-9.3) µg mL-1, and the inhibition was from 50 % to 70 %. Four of five aflatoxin non-producing strains of A. flavus interfered with aflatoxin production in mixed culture, and reduced AFB1 productivity by 100 %. One strain showed a lower efficacy in inhibiting AFB1 production (80 %) with a detectable amount of AFB1 3.7 µg mL-1 when compared to control. A decrease in toxin production was also observed in dual cultivation with A. niger strains. It resulted in 100 % reduction in three strains), 90 % reduction in one strain (Cmean=1.9 µg mL-1) and 80 % reduction in one strain (Cmean=3.7 µg mL-1) inhibition.Cilj rada bio je procijeniti biotske interakcije između sojeva različitih vrsta plijesni i kontrolnog soja Aspergillus flavus NRRL 3251, producenta aflatoksina B1 (AFB1). Inhibitorno djelovanje u miješanim kulturama na tvorbu AFB1 ispitano je na dvadeset pet sojeva Alternaria, Cladosporium, Mucor i Aspergillus vrsta izoliranih iz zraka, strugotina pljesnivih zidova te uskladištenog i prezimljenog kukuruza. Biosinteze su provedene u tekućoj hranjivoj podlozi s kvaščevim ekstraktom (YESbujon). Ekstrakcije AFB1 iz biomase izvršene su multitoksinskom metodom tankoslojne kromatografije. Rezultati biotskih interakcija pokazali su antagonistički odnos svih testiranih sojeva. Alternaria i Cladosporium vrste simultano inokulirane sporama A. flavus NRRL 3251 inhibirale su tvorbu AFB1 100 % u odnosu na dokazani toksin u kontrolnoj biosintezi (konc. 18,7 µg mL-1). U miješanim kulturama vrstama roda Mucor dokazane su padajuće koncentracije AFB1 (9,3 µg mL-1, 7,5 µg mL-1 i 5,6 µg mL-1), odnosno inhibicija tvorbe toksina 50 % do 70 %. Atoksinogeni sojevi A. flavus inhibirali su tvorbu AFB1 80 % (1 soj, konc. 3,7 µg mL-1) i 100 % (4 soja). Antagonističko djelovanje prema toksinogenom soju, smanjujući tvorbu AFB1 u rasponu 80 % do 100 % (konc. 1,9 µg mL-1 i 3,7 µg mL-1), dokazano je u uzgojnim biosintezama s A. niger

Diet, physical activity, and adiposity in children in poor and rich neighbourhoods: a cross-sectional comparison

BACKGROUND: Obesity in Canadian children increased three-fold in twenty years. Children living in low-income neighborhoods exercise less and are more overweight than those living in more affluent neighborhoods after accounting for family socio-economic status. Strategies to prevent obesity in children have focused on personal habits, ignoring neighborhood characteristics. It is essential to evaluate diet and physical activity patterns in relation to socio-economic conditions to understand the determinants of obesity. The objective of this pilot study was to compare diet, physical activity, and the built environment in two Hamilton area elementary schools serving socio-economically different communities. METHODS: We conducted a cross-sectional study (November 2005-March 2006) in two public elementary schools in Hamilton, Ontario, School A and School B, located in low and high socioeconomic areas respectively. We assessed dietary intake, physical activity, dietary restraint, and anthropometric measures in consenting children in grades 1 and higher. From their parents we assessed family characteristics and walkability of the built environment. RESULTS: 160 children (n = 48, School A and n = 112, School B), and 156 parents (n = 43, School A and n = 113, School B) participated in this study. The parents with children at School A were less educated and had lower incomes than those at School B. The School A neighborhood was perceived to be less walkable than the School B neighborhood. Children at School A consumed more baked foods, chips, sodas, gelatin desserts, and candies and less low fat dairy, and dark bread than those at School B. Children at School A watched more television and spent more time in front of the computer than children studying at School B, but reported spending less time sitting on weekdays and weekends. Children at both schools were overweight but there was no difference in their mean BMI z-scores (School A = 0.65 versus School B = 0.81, p-value = 0.38). CONCLUSION: The determinants of overweight in children may be more complex than imagined. In future intervention programs researchers may consider addressing environmental factors, and customizing lifestyle interventions so that they are closer to community needs