Bio-inspired design of ice-retardant devices based on benthic marine invertebrates: the effect of surface texture

Growth of ice on surfaces poses a challenge for both organisms and for devices that come into contact with liquids below the freezing point. Resistance of some organisms to ice formation and growth, either in subtidal environments (e.g. Antarctic anchor ice), or in environments with moisture and cold air (e.g. plants, intertidal) begs examination of how this is accomplished. Several factors may be important in promoting or mitigating ice formation. As a start, here we examine the effect of surface texture alone. We tested four candidate surfaces, inspired by hard-shelled marine invertebrates and constructed using a three-dimensional printing process. We screened biological and artifical samples for ice formation and accretion in submerged conditions using previous methods, and developed a new test to examine ice formation from surface droplets as might be encountered in environments with moist, cold air. It appears surface texture plays only a small role in delaying the onset of ice formation: a stripe feature (corresponding to patterning found on valves of blue mussels, Crassostrea gigas, or on the spines of the Antarctic sea urchin, Sterechinus neumayeri) slowed ice formation an average of 25% compared to a grid feature (corresponding to patterning found on sub-polar butterclams, Saxidomas). The geometric dimensions of the features have only a small (~6%) effect on ice formation. Surface texture affects ice formation, but does not explain by itself the large variation in ice formation and species-specific ice resistance observed in other work. This suggests future examination of other factors, such as material elastic properties and coatings, and their interaction with surface pattern

A study of seroprevalence of rubella IgG in Maltese adolescents

The objective of this study was to determine the seroprevalence of rubella IgG antibodies in Maltese adolescents, through a cross-sectional study, with mailed questionnaire and blood sampling. The subjects tested were 172 individuals, aged 14-15 years from Malta and Gozo for the prevalence of vaccination and seropositivity (IgG) for rubella. The results of the 85% individuals vaccinated seropositivity was detected in 168 youths (97.7%). The study showed a high level of detectable humoral immunity to rubella but this could not be definitively attributed to vaccination alone.peer-reviewe

Post-activation Potentiation: Increasing Power Output in the Block Power Clean

The effect of post-activation potentiation has been shown to increase both jumping height and sprinting over short distances (Wilson, et al., 2013). PURPOSE: The purpose of this study was to examine if a PAP protocol could also enhance bar-velocity (m/s) in the block power clean, a movement commonly used in strength and conditioning to enhance explosive athletic attributes such as jumping and sprinting. METHODS: ECU throwers (n=6, 67% male) participated in two session separated by three to 14 days. The first session consisted of a three-to-five repetition max of the block power clean using the Auto-regulated Progressive Resistance Exercise method, vertical jump, and a training history questionnaire. During the second session, participants performed a series of trials testing peak bar-velocity of the block power clean following a 6-second maximum voluntary isometric contraction (MVIC). Rest times were counter-balanced, varied between 15 and 120 seconds of rest between the MVIC and block power clean. Mean differences and effect sizes were calculated on the peak bar-velocities. RESULTS: Our results indicate that 15, 30, 90, and 120 seconds rest increase the peak bar-velocity. The highest effect size (ES= 1.159) and mean difference (MD= 0.123) were seen with 90 seconds of rest compared to the baseline. CONCLUSION: These initial findings suggest that the effects of post-activation Potentiation can increase peak bar-velocity of the block power clean in collegiate athletes when given appropriate rest. These finding hold important implications for training applications, however, further analysis and testing is needed

Men are cheaper than gold : English sailors and their irreligiousness towards society, 1560-1642.

The English common sailor rose from his humble beginnings to the pinnacle of renown and fame during the repulsion of the Spanish Armada in 1588. Afterwards, with the rise of the privateer and the merchant ships, the Royal Navy found it difficult to retain quality mariners. Following many decades of deriding and dehumanizing the tar, the men engendered and reproduced an attitude of irreligiousness towards religion in general and Christianity in particular, mocking the officers who represented the society, which denigrated them. This paper will explore the practices and transmission types of this irreligiousness and the way the state attempted to utilize the seamen to extend their power while simultaneously minimizing their importance to society. Using mainly sailor memoirs or pamphlets from the period, the paper also examines how contemporary historians and those of successive generations viewed the irreligiousness of the seamen. In the mid-sixteenth century, authorities initiated intensive regulations and discipline, which historians later labeled as Biopower, in shaping and controlling the behavior of the British sailor for the good of the state, which in turn led the men to exhibit agency, in the forms of irreligiousness, employment choice, and their very lifestyle, in resisting this drive to become high society's view of British. In due course at the beginning of it all, the hypocrisy of the established society juxtaposed against the sailor who enjoyed life to the fullest in an attempt to handle the stresses of this never before seen deep sea lengthy voyages demonstrates two differing tales of this early age of sail for the English. One story depicts the dashing officer rallying men onward to capture the prize or prevail against the raging storm, afterwards asking all to bow their heads as they thanked God for their deliverance. This same yarn shows the exasperated lieutenant, trudging from tavern to brothel, searching for the able but alcoholic tar and beseeching him to sign on for a voyage, for his own good, so he could attain some money for himself and perhaps his future. The other tale relates overbearing officers, usually hapless but mostly cruel, looking for their own gain on the backs of sailors and slaves, all the while committing the same kinds of acts he admonished the men for doing. The truth, as anyone looking back over so many centuries and relying on manuscripts and journals can detect, most likely resides somewhere in the middle but probably nearer to the cruel officer theme. British society did engage in applying Biopower to controlling the sailors and that the seamen used agency in their irreligiousness to fight back. This paper shines a light on an aspect of mariner agency that has been often overlooked. Their very lifestyles and indifference to prudent living such as savings, church-going, and other forms of high society shows they fought against the system which sought to control them with their very lives and minds

Characterizing the Developmental and Reproductive Toxicities of Cannabidiol and Δ9-Tetrahydrocannabinol

Medical marijuana is legal in twenty-nine of the United States and an additional nineteen states have passed legislation for cannabidiol (CBD) treatment of drug-resistant epilepsy, such as Dravet Syndrome (DS) which is diagnosed in children as young as two months. While CBD has shown anecdotal and recently clinical trial efficacy in reducing seizure frequency in DS patients, little is known about the potential adverse side-effects on child physiology, brain development, adult disease, or subsequent generations. Moreover, CBD is rarely administered without including low concentrations of Δ9-tetrahydrocannabinol (THC). The goal of this project is to characterize the relative morphological, behavioral, reproductive, and multigenerational toxicities following a developmental F0 exposure to 0.024–5 mg/L (0.08–16 µM) THC or 0.006–1.2 mg/L (0.02–4 µM) CBD. In this study, THC was used as a positive control due to its established developmental toxicities. An additional goal of this project was to analytically confirm THC and CBD concentrations during waterborne exposure as well as the bioconcentration in zebrafish. Following a developmental exposure, CBD posed similar risk to development, reproduction, and behavior as THC, but at much lower concentrations. Also, CBD bioconcentrated in zebrafish more readily than THC. To our knowledge, this is the first study to systematically compare the harmful effects on development and behavior of the two most prevalent and widely used phytocannabinoids. While most patients with drug-resistant forms of epilepsy and debilitating seizures choose cannabinoids in desperation, more research is necessary into their developmental toxicity to better understand both their therapeutic and toxic mechanisms of action

Traditionalism and the Idea of Progress: A Case for Ideological Mobilization in Communist China

Economic development is not a one-dimensional process whereby a country's productivity and Gross National Product increase, machines are substituted for men, and new products appear. Development is characterized by the creation of a new society. For economic development to come about, changes must occur in traditional man's perception of his social and physical environment and his relationship to it. This is essential if traditional man and his society are to break out of the stability and fatalism of poverty, escape from superstition and ignorance, and overcome the inertia of social custom and vested interest. The purpose of this article is to examine how ideological mobilization in Mao Tse-tung's China has functioned to undermine traditional impediments to economic development and instil the idea that progress is both possible and desirable.http://web.ku.edu/~starjrn