Melatonin for cardioprotection in ST elevation myocardial infarction: Are we ready for the challenge?

Melatonin, an endocrine product of the pineal gland, is formed predominantly during the nighttime. Light has an inhibitory effect on pineal melatonin secretion. Pineal melatonin release is synchronised by this daily light-dark cycle via a multisynaptic pathway between the eyes and the pineal gland. Light stimulates the retina to modulate the activity of the suprachiasmatic nucleus, the master biological clock.1 The suprachiasmatic nucleus controls pineal melatonin synthesis and the concentrations of melatonin in the sera of healthy subjects, which reach values of 10−10 to 10−9 mol/L during the night, with much lower concentrations being present during the day. Many publications have shown that melatonin has an important role in a variety of cardiovascular pathophysiologic processes: the indoleamine has anti-inflammatory, antioxidant, antihypertensive, antithrombotic and antilipaemic properties.

Shedder status— An analysis of self and non-self DNA in multiple handprints deposited by the same individuals over time

There are several studies that suggest that different people deposit different quantities of their own DNA on items they touch, i.e. some are good shedders and others are bad shedders. It is of interest to determine if individuals deposit consistent quantities of their own DNA, no matter the occasion, as well as the degree of variability among individuals. To investigate this, participants were tested for their ability to deposit DNA by placing right and left handprints on separate DNA-free glass plates at three set times during the day (morning, midday and afternoon) on four different days spaced over several weeks. Information regarding recent activities performed by the individual was recorded, along with information on gender, hand dominance and hand size. A total of 240 handprint deposits were collected from 10 individuals and analyzed for differences in DNA quantity and the type of the DNA profile obtained at different times of the day, on different days, between the two hands of the same individual, and between different individuals. Furthermore, the correlation between the deposit quantity and the ratio of self to non-self DNA in the mixed deposits was analyzed to determine if the amount of non-self DNA has an effect on overall DNA quantities obtained. In general, this study has shown that while there is substantial variation in the quantities deposited by individuals on different occasions, some clear trends were evident with some individuals consistently depositing significantly more or less DNA than others. Non-self DNA was usually deposited along with self DNA and, in most instances, was the minor component. Incidents where the non-self portion was the major component were very rare and, when observed, were associated with a poor depositor/shedder. Forensic DNA scientists need to consider the range and variability of DNA a person deposits when touching an object, the likelihood of non-self DNA being co-deposited onto the handled object of interest and the factors that may affect the relative quantity of this component within the deposit.

Movement and habitat use of the freshwater catfish (Tandanus tandanus) in a remnant floodplain wetland

Knowledge of the movement and habitat use of fishes is important in identifying and understanding the causes of population declines and predicting how populations are likely to respond to management interventions. In this study, radiotelemetry was used to examine the spring and summer movement and habitat use patterns of the freshwater catfish (Tandanus tandanus) in a remnant wetland to inform the development of recovery actions for this threatened species. Twenty-one adult fish were tagged and released within Tahbilk Lagoon, Victoria, Australia, in September 2009. Fish were located every 1-2 weeks between September 2009 and February 2010, a period which coincides with the spawning period for the species. Eleven of the fish were also tracked every 2 h for 68 consecutive hours in December 2009 to examine diel movements. The study revealed that freshwater catfish make extensive use of cover (e.g. wood and macrophytes) and typically have limited ranges (median total linear range and 90% linear range 599 and 173 m respectively), although they occasionally moved more extensively (up to 1.5 km) between floodplain and riverine habitats. Fish moved over much greater areas at night compared with during the day. There was also evidence of sex-specific variation in movement, with a trend for greater movement of female fish at night compared with males. The results of the study suggest that strategies that protect macrophyte and wood habitats and improve connectivity between riverine and floodplain habitats are likely to be important in maintaining and restoring remnant populations of this species.

Annual Report 2-15 Office of the Chief Information Officer, January 2016

In 2015, the OCIO worked across a broad range of projects and key initiatives in alignment with these goals. As an IT organization supporting services consumed by every agency of the State of Iowa (State), our key enterprise initiatives are conducted in addition to the day-to-day support activities required to keep government IT services operational and secure. These initiatives maintain alignment with key efficiency goals established by Governor Branstad and with specific legislative mandates.

Comparative Behavior of Wild and Hatchery Reared White Sea Bream (Diplodus sargus) Released on Artificial Reefs Off the Algarve (Southern Portugal)

Three hatchery produced and reared (HPR) and five wild white sea bream (Diplodus sargus) were double tagged with Vemco V8SC-2L acoustic transmitters and Floy Tag T-bar anchor tags, and released on artificial reefs located near a natural reef off the southern coast of Portugal. Passive telemetry was used to monitor movements of the white sea bream over a nine week period from April to June 2007. Differences in behavior at release, habitat association (artificial vs. natural reef), and in daily movements were registered. Wild fish moved from one habitat to the other with increased preference for the artificial habitat during the day, whereas HPR fish showed no site fidelity or consistent daily movement pattern and left the release site soon after release. Comparison of Minimum Convex Polygon (MCP) showed a higher area usage by wild fish. This experiment shows that these artificial reefs are used on a daily basis by wild white sea bream but apparently are not optimal release locations for hatchery produced white sea bream.

Reticence or vigilance at the nest: a cruel bind for the endangered Black-capped Vireo

Breeding birds vocalize to find mates and establish and defend territories, but these same critical communications may also attract predators or brood parasites, placing birds in a cruel bind. Although vigilant birds may better maintain social relationships with mates and neighbors through frequent vocalizations, reticent birds may reduce risk to their nests by being relatively quiet and making infrequent vocalizations. Selection for vocalization patterns that minimize brood parasitism might be particularly strong for birds that are unable to fledge both their own young and the parasite. Temporal plasticity in the frequency of vocalizations near nests, however, may allow birds to balance trade-offs and optimize nest-defense strategies. The Black-capped Vireo (Vireo atricapilla) is an endangered songbird that faces intensive brood parasitism in areas where Brown-headed Cowbirds (Molothrus ater) are present. Vireo nests that produce cowbird fledglings always fail to fledge vireo young. We recorded vocalizations at vireo nests across three nesting stages (building, laying, and early incubation) and three periods of the day (morning, midday, and evening) and compared vocalization frequency with eventual depredation or parasitism fate as well as local cowbird density to test two hypotheses. The predator-attraction hypothesis predicts that predators will be attracted by frequent vocalizations, whereas cowbirds will parasitize nests with relatively quiet parents and less predation risk; thus, vireos will experience trade-offs between reticence and vigilance in mediating specific risks. The parasite-assessment hypothesis predicts that vireos will become more secretive as local cowbird densities increase. Vireo vocalization response to nest predation and parasitism risk interacted with nest stage, and we found little evidence of risk mediation through vocalizations except during the building stage. Vireos, however, did benefit overall by optimizing temporal patterns in vocalizations. Vireo nests were less likely to be depredated or parasitized if males vocalized most during laying and least during the middle of the day. Birds vocalized more during the midday and less during the laying period when local cowbird densities were higher, however, perhaps demonstrating limited plasticity in social communication.

Optimal Wind Bidding Strategies in Day-Ahead Markets

This paper presents a computer application for wind energy bidding in a day-ahead electricity market to better accommodate the variability of the energy source. The computer application is based in a stochastic linear mathematical programming problem. The goal is to obtain the optimal bidding strategy in order to maximize the revenue. Electricity prices and financial penalties for shortfall or surplus energy deliver are modeled. Finally, conclusions are drawn from an illustrative case study, using data from the day-ahead electricity market of the Iberian Peninsula.

Atmospheric electrical field measurements near a fresh water reservoir and the formation of the lake breeze

In order to access the effect of the lakes in the atmospheric electrical field, measurements have been carried out near a large man-made lake in southern Portugal, the Alqueva reservoir, during the ALqueva hydro-meteorological EXperiment 2014. The purpose of these conjoint experiments was to study the impact of the Alqueva reservoir on the atmosphere, in particular on the local atmospheric electric environment by comparing measurements taken in the proximity of the lake. Two stations 10 km apart were used, as they were located up- and down-wind of the lake (Amieira and Parque Solar, respectively), in reference to the dominant northwestern wind direction. The up-wind station shows lower atmospheric electric potential gradient (PG) values than the ones observed in the down-wind station between 12 and 20 UTC. The difference in the atmospheric electric PG between the up-wind and the down-wind station is ~30 V/m during the day. This differential occurs mainly during the development of a lake breeze, between 10 and 18 UTC, as a consequence of the surface temperature gradient between the surrounding land and the lake water. In the analysis presented, a correlation is found between the atmospheric electric PG differences and both wind speed and temperature gradients over the lake, thus supporting the influence of the lake breeze over the observed PG variation in the two stations. Two hypotheses are provided to explain this observation: (1) The air that flows from the lake into the land station is likely to increase the local electric conductivity through the removal of ground dust and the transport of cleaner air from higher altitudes with significant light ion concentrations. With such an increase in conductivity, it is expected to see a reduction of the atmospheric electric PG; (2) the resulting air flow over the land station carries negative ions formed by wave splashing in the lake's water surface, as a result of the so-called balloelectric effect. These negative ions will form a space-charge density (SCD) that can reduce the atmospheric electric PG. A formulation is derived here in order to estimate the local SCD.

Lake–atmosphere interactions at Alqueva reservoir: a case study in the summer of 2014

The study of lake–atmosphere interactions was the main purpose of a 2014 summer experiment at Alqueva reservoir in Portugal. Near-surface fluxes of momentum, heat and mass [water vapour (H2O) and carbon dioxide (CO2)] were obtained with the new Campbell Scientific’s IRGASON Integrated Open-Path CO2/H2O Gas Analyser and 3D Sonic Anemometer between 2 June and 2 October. On average, the reservoir was releasing energy in the form of sensible and latent heat flux during the study period. At the end of the 75 d, the total evaporation was estimated as 490.26 mm. A high correlation was found between the latent heat flux and the wind speed (R = 0.97). The temperature gradient between air and water was positive between 12 and 21 UTC, causing a negative sensible heat flux, and negative during the rest of the day, triggering a positive sensible heat flux. The reservoir acted as a sink of atmospheric CO2 with an average rate of −0.026 mg m−2 s−1. However, at a daily scale we found an unexpected uptake between 0 and 9 UTC and almost null flux between 13 and 19 UTC. Potential reasons for this result are further discussed. The net radiation was recorded for the same period and water column heat storage was estimated using water temperature profiles. The energy balance closure for the analysed period was 81%. In-water solar spectral downwelling irradiance profiles were measured with a new device allowing measurements independent of the solar zenith angle, which enabled the computation of the attenuation coefficient of light in the water column. The average attenuation coefficient for the photosynthetically active radiation spectral region varied from 0.849 ± 0.025 m−1 on 30 July to 1.459 ± 0.007 m−1 on 25 September.

The Students’ Perspective of Geometry Teaching and Learning in High School

The purpose of this article is to present the results obtained from a questionnaire applied to Costa Rican high school students, in order to know their perspectives about geometry teaching and learning. The results show that geometry classes in high school education have been based on a traditional system of teaching, where the teacher presents the theory; he presents examples and exercises that should be solved by students, which emphasize in the application and memorization of formulas. As a consequence, visualization processes, argumentation and justification don’t have a preponderant role. Geometry is presented to students like a group of definitions, formulas, and theorems completely far from their reality and, where the examples and exercises don’t possess any relationship with their context. As a result, it is considered not important, because it is not applicable to real life situations. Also, the students consider that, to be successful in geometry, it is necessary to know how to use the calculator, to carry out calculations, to have capacity to memorize definitions, formulas and theorems, to possess capacity to understand the geometric drawings and to carry out clever exercises to develop a practical ability.