A study of all-fluid, high-temperature-sensing probes

Fluidics concept applied to miniaturized all-fluid high temperature sensing probes for use in hypervelocity wind tunnel

Sequence-Dependent Fluorescence of Cyanine Dyes on Microarrays

Cy3 and Cy5 are among the most commonly used oligonucleotide labeling molecules. Studies of nucleic acid structure and dynamics use these dyes, and they are ubiquitous in microarray experiments. They are sensitive to their environment and have higher quantum yield when bound to DNA. The fluorescent intensity of terminal cyanine dyes is also known to be significantly dependent on the base sequence of the oligonucleotide. We have developed a very precise and high-throughput method to evaluate the sequence dependence of oligonucleotide labeling dyes using microarrays and have applied the method to Cy3 and Cy5. We used light-directed in-situ synthesis of terminally-labeled microarrays to determine the fluorescence intensity of each dye on all 1024 possible 5′-labeled 5-mers. Their intensity is sensitive to all five bases. Their fluorescence is higher with 5′ guanines, and adenines in subsequent positions. Cytosine suppresses fluorescence. Intensity falls by half over the range of all 5-mers for Cy3, and two-thirds for Cy5. Labeling with 5′-biotin-streptavidin-Cy3/-Cy5 gives a completely different sequence dependence and greatly reduces fluorescence compared with direct terminal labeling

Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

Two-Item Fall Screening Tool Identifies Older Adults at Increased Risk of Falling after Emergency Department Visit

Introduction: Few emergency department (ED)-specific fall-risk screening tools exist. The goals of this study were to externally validate Tiedemann et al’s two-item, ED-specific fall screening tool and test handgrip strength to determine their ability to predict future falls. We hypothesized that both the two-item fall screening and handgrip strength would identify older adults at increased risk of falling.Methods: A convenience sample of patients ages 65 and older presenting to a single-center academic ED were enrolled. Patients were asked screening questions and had their handgrip strength measured during their ED visit. Patients were given one point if they answered “yes” to “Are you taking six or more medications?” and two points for answering “yes” to “Have you had two or more falls in the past year?” to give a cumulative score from 0 to 3. Participants had monthly follow- ups, via postcard questionnaires, for six months after their ED visit. We performed sensitivity and specificity analyses, and used likelihood ratios and frequencies to assess the relationship between risk factors and falls, fall-related injury, and death.Results: In this study, 247 participants were enrolled with 143 participants completing follow-up (58%). During the six-month follow-up period, 34% of participants had at least one fall and 30 patients died (12.1%). Fall rates for individual Tiedemann scores were 14.3%, 33.3%, 60.0% and 72.2% for scores of 0,1, 2 and 3, respectively. Low handgrip strength was associated with a higher proportion of falls (46.3%), but had poor sensitivity (52.1%).Conclusion: Handgrip strength was not sensitive in screening older adults for future falls. The Tiedemann rule differentiated older adults who were at high risk for future falls from low risk individuals, and can be considered by EDs wanting to screen older adults for future fall risk

Plant-to-Plant Variability in Corn Production

Corn (Zea mays L.) grain yields are known to vary from plant to plant, but the extent of this variability across a range of environments has not been evaluated. This study was initiated to evaluate by-plant corn grain yield variability over a range of production environments and to establish the relationships among mean grain yield, standard deviation, coefficient of variation, and yield range. A total of forty-six 8- to 30-m corn transects were harvested by plant in Argentina, Mexico, Iowa, Nebraska, Ohio, Virginia, and Oklahoma from 2002 to 2004. By-plant corn grain yields were determined, and the average individual plant yields were calculated. Over all sites in all countries and states, plant-to-plant variation in corn grain yield averaged 2765 kg ha-1 (44.1 bu ac-1). At the sites with the highest average corn grain yield (11 478 and 14 383 kg ha-1, Parana Argentina, and Phillips, NE), average plant-to-plant variation in yield was 4211 kg ha-1 (67 bu ac-1) and 2926 kg ha-1 (47 bu ac-1), respectively. As average grain yields increased, so did the standard deviation of the yields obtained within each row. Furthermore, the yield range (maximum corn grain yield minus the minimum corn grain yield per row) was found to increase with increasing yield level. Regardless of yield level, plant-to-plant variability in corn grain yield can be expected and averaged more than 2765 kg ha-1 over sites and years. Averaging yield over distances \u3e0.5 m removed the extreme by-plant variability, and thus, the scale for treating other factors affecting yield should be less than 0.5 m. Methods that homogenize corn plant stands and emergence may decrease plant-to-plant variation and could lead to increased grain yields