The efficacy of 'static' training interventions for improving indices of cardiorespiratory fitness in premenopausal females.

PURPOSE: Cardiovascular disease (CVD) is the leading cause of death worldwide. Many risk factors for CVD can be modified pharmacologically; however, uptake of medications is low, especially in asymptomatic people. Exercise is also effective at reducing CVD risk, but adoption is poor with time-commitment and cost cited as key reasons for this. Repeated remote ischaemic preconditioning (RIPC) and isometric handgrip (IHG) training are both inexpensive, time-efficient interventions which have shown some promise in reducing blood pressure (BP) and improving markers of cardiovascular health and fitness. However, few studies have investigated the effectiveness of these interventions in premenopausal women. METHOD: Thirty healthy females were recruited to twelve supervised sessions of either RIPC or IHG over 4 weeks, or acted as non-intervention controls (CON). BP measurements, flow-mediated dilatation (FMD) and cardiopulmonary exercise tests (CPET) were performed at baseline and after the intervention period. RESULTS: IHG and RIPC were both well-tolerated with 100% adherence to all sessions. A statistically significant reduction in both systolic (- 7.2 mmHg) and diastolic (- 6 mmHg) BP was demonstrated following IHG, with no change following RIPC. No statistically significant improvements were observed in FMD or CPET parameters in any group. CONCLUSIONS: IHG is an inexpensive and well-tolerated intervention which may improve BP; a key risk factor for CVD. Conversely, our single arm RIPC protocol, despite being similarly well-tolerated, did not elicit improvements in any cardiorespiratory parameters in our chosen population.

Antimicrobial binding and growth kinetics in BacT/ALERT® FA Plus and BACTEC® Aerobic/F Plus blood culture media.

The capacity of absorbent beads in BacT/ALERT® FA Plus and BACTEC® Aerobic/F Plus blood culture bottles to bind and neutralize antibiotics was compared. Binding was established using reverse-phase HPLC, and inactivation was based on the recovery of susceptible test stains from simulated blood cultures. The FA Plus medium demonstrated more rapid and better overall binding kinetics for each drug tested, resulting in significantly better overall recovery rates. Differences in time to detection favored the FA Plus medium for three drug/organism combinations and Aerobic/F Plus for two.

The diets of school-aged Aboriginal youths in Canada: a systematic review of the literature.

BACKGROUND: Most national surveys examining diet leave large segments of the Aboriginal population under-represented. The present study aimed to: (i) review primary research studies that investigated the dietary intakes of Canadian school-aged Aboriginal youths; (ii) summarise the tools and methodologies currently used to measure diet in this population; and (iii) identify knowledge gaps and suggest areas of future research. METHODS: A systematic review of research published between January 2004 and January 2014 related to the diets of Canadian school-aged (6-18 years) Aboriginal youths was undertaken, including Medline, Scopus, ERIC, Web of Science and Google Scholar databases. Studies were summarised based on purpose, year, sample population, setting, dietary assessment method and main findings. RESULTS: Twenty-four studies were reviewed, all of which were cross-sectional in design. Most (n = 16; 67%) were from Ontario or Quebec, investigated the diets of First Nations (n = 21; 88%) youths and took place in remote or isolated settings (n = 18; 75%). Almost all of the studies used the 24-h recall to assess intake (n = 19; 79%), of which 89% used a single recall. The findings suggest that the diets of Aboriginal youths could be improved. Of particular concern are inadequate intakes of vegetables and fruit, milk and alternatives, fibre, folate, vitamin A, vitamin C, calcium and vitamin D, concomitant with an excess consumption of sugar sweetened beverages, snacks and fast foods. Traditional foods remain important but tend to be consumed infrequently. CONCLUSIONS: The diets of Canadian Aboriginal youths are energy-dense and nutrient-poor. The diets of Inuit and Métis youths, in particular, and perceptions of a balanced diet warrant further investigation.

Seeking the sun in deep, dark places: mesopelagic sightings of ocean sunfishes (Molidae).

Evidence is presented from publicly available remotely operated vehicle (ROV) footage that suggests deep-water ranging in ocean sunfishes (family Molidae) is more common than typically thought, including a new maximum depth recorded for the southern sunfish Mola ramsayi.

Body Mass Index of First Nations youth in Ontario, Canada: influence of sleep and screen time.

INTRODUCTION: Prevalence rates of overweight and obesity in Canada have risen rapidly in the past 20 years. Concurrent with the obesity epidemic, sleep time and physical activity levels have decreased among youth. Aboriginal youth experience disproportionately high obesity prevalence but there is inadequate knowledge of contributing factors. This research aimed to examine sleep and screen time behavior and their relationship to Body Mass Index (BMI) in on-reserve First Nations youth from Ontario, Canada. METHODS: This was an observational population-based study of cross-sectional design. Self-reported physical activity, screen time, and lifestyle information was collected from 348 youth aged 10-18 years residing in five northern, remote First Nations communities and one southern First Nations community in Ontario, Canada, from October 2004 to June 2010. Data were collected in the school setting using the Waterloo Web-based Eating Behaviour Questionnaire. Based on self-reported height and weight, youth were classified normal (including underweight), overweight and obese according to BMI. Descriptive cross-tabulations and Pearson's χ² tests were used to compare screen time, sleep habits, and physical activity across BMI categories. RESULTS: Participants demonstrated low levels of after-school physical activity, and screen time in excess of national guidelines. Overall, 75.5% reported being active in the evening three or less times per week. Approximately one-quarter of the surveyed youth watched more than 2 hours of television daily and 33.9% spent more than 2 hours on the internet or playing video games. For boys, time using the internet/video games (p=0.022) was positively associated with BMI category, with a greater than expected proportion of obese boys spending more than 2 hours using the internet or video games daily (56.7%). Also for boys, time spent outside after school (p=0.033) was negatively associated with BMI category, with a lesser than expected proportion spending 'most of the time' outside (presumably being active) after school. These relationships were not observed in girls. Adjusted standardized residuals suggest a greater than expected proportion of obese individuals had a television in their bedroom (66.7%) as compared with the rest of the population. CONCLUSIONS: The current study adds to the limited information about contributors to overweight and obesity in First Nations youth living on-reserve in Canada. Concerns about inadequate sleep, excess screen time, and inadequate physical activity mirror those of the general population. Further investigation is warranted to improve the understanding of how various lifestyle behaviors influence overweight, obesity, and the development of chronic disease among First Nations youth. Initiatives to reduce screen time, increase physical activity, and encourage adequate sleep among on-reserve First Nations youth are recommended.

Challenging the highstand-dormant paradigm for land-detached submarine canyons.

Sediment, nutrients, organic carbon and pollutants are funnelled down submarine canyons from continental shelves by sediment-laden flows called turbidity currents, which dominate particulate transfer to the deep sea. Post-glacial sea-level rise disconnected more than three quarters of the >9000 submarine canyons worldwide from their former river or long-shore drift sediment inputs. Existing models therefore assume that land-detached submarine canyons are dormant in the present-day; however, monitoring has focused on land-attached canyons and this paradigm remains untested. Here we present the most detailed field measurements yet of turbidity currents within a land-detached submarine canyon, documenting a remarkably similar frequency (6 yr-1) and speed (up to 5-8 ms-1) to those in large land-attached submarine canyons. Major triggers such as storms or earthquakes are not required; instead, seasonal variations in cross-shelf sediment transport explain temporal-clustering of flows, and why the storm season is surprisingly absent of turbidity currents. As >1000 other canyons have a similar configuration, we propose that contemporary deep-sea particulate transport via such land-detached canyons may have been dramatically under-estimated.

Comparative Efficacy of Intramuscular and Scarification Routes of Administration of Live Smallpox Vaccine in a Murine Challenge Model.

In recent years concern has mounted regarding the possibility of a re-emergence of smallpox through biowarfare or bioterrorism. There is also concern over the incidence of human monkeypox in endemic areas and the potential for monkeypox to be accidentally transported to non-endemic areas. In the event of re-emergence of smallpox or emergence of monkeypox, the accepted route of administration for live replicating smallpox vaccine is dermal scarification, which generates a virus-shedding lesion that persists for several days at the vaccination site. The lesion is a potential source of contact transmission of vaccine to individuals who may be contra-indicated for receipt of the live vaccine. In this study, we compare dermal scarification with intramuscular vaccination for replicating smallpox vaccine in a mouse lethal challenge model. Comparisons are made over multiple vaccine and challenge doses and data recorded for lethality, disease severity, and antibody responses. Qualitative and quantitative differences between the two routes are observed, and for the intramuscular route the febrile response is not suppressed after subsequent virulent vaccinia virus challenge. However both routes generate an immune response and protect from severe disease and death. Although dermal scarification is the preferred route of vaccination for the general population, intramuscular vaccination may be an option for people who are not contraindicated for the live vaccine, but who are close contacts of people who are contraindicated for the live vaccine, in an emergency situation.

The metabolic impact of extracellular nitrite on aerobic metabolism of Paracoccus denitrificans.

Nitrite, in equilibrium with free nitrous acid (FNA), can inhibit both aerobic and anaerobic growth of microbial communities through bactericidal activities that have considerable potential for control of microbial growth in a range of water systems. There has been much focus on the effect of nitrite/FNA on anaerobic metabolism and so, to enhance understanding of the metabolic impact of nitrite/FNA on aerobic metabolism, a study was undertaken with a model denitrifying bacterium Paracoccus denitrificans PD1222. Extracellular nitrite inhibits aerobic growth of P. denitrificans in a pH-dependent manner that is likely to be a result of both nitrite and free nitrous acid (pKa = 3.25) and subsequent reactive nitrogen oxides generated from the intracellular passage of FNA into P. denitrificans. Increased expression of a gene encoding a flavohemoglobin protein (Fhp) (Pden_1689) was observed in response to extracellular nitrite. Construction and analysis of a deletion mutant established Fhp to be involved in endowing nitrite/FNA resistance at high extracellular nitrite concentrations. Global transcriptional analysis confirmed nitrite-dependent expression of fhp and indicated that P. denitrificans expressed a number of stress response systems associated with protein, DNA and lipid repair. It is therefore suggested that nitrite causes a pH-dependent stress response that is due to the production of associated reactive nitrogen species, such as nitric oxide from the internalisation of FNA.

Nitrous Oxide Metabolism in Nitrate-Reducing Bacteria: Physiology and Regulatory Mechanisms.

Nitrous oxide (N2O) is an important greenhouse gas (GHG) with substantial global warming potential and also contributes to ozone depletion through photochemical nitric oxide (NO) production in the stratosphere. The negative effects of N2O on climate and stratospheric ozone make N2O mitigation an international challenge. More than 60% of global N2O emissions are emitted from agricultural soils mainly due to the application of synthetic nitrogen-containing fertilizers. Thus, mitigation strategies must be developed which increase (or at least do not negatively impact) on agricultural efficiency whilst decrease the levels of N2O released. This aim is particularly important in the context of the ever expanding population and subsequent increased burden on the food chain. More than two-thirds of N2O emissions from soils can be attributed to bacterial and fungal denitrification and nitrification processes. In ammonia-oxidizing bacteria, N2O is formed through the oxidation of hydroxylamine to nitrite. In denitrifiers, nitrate is reduced to N2 via nitrite, NO and N2O production. In addition to denitrification, respiratory nitrate ammonification (also termed dissimilatory nitrate reduction to ammonium) is another important nitrate-reducing mechanism in soil, responsible for the loss of nitrate and production of N2O from reduction of NO that is formed as a by-product of the reduction process. This review will synthesize our current understanding of the environmental, regulatory and biochemical control of N2O emissions by nitrate-reducing bacteria and point to new solutions for agricultural GHG mitigation.

Comprehensive analysis of the acute toxicities induced by systemic administration of cationic lipid:plasmid DNA complexes in mice.

A major limitation associated with systemic administration of cationic lipid:plasmid DNA (pDNA) complexes is the vector toxicity at the doses necessary to produce therapeutically relevant levels of transgene expression. Systematic evaluation of these toxicities has revealed that mice injected intravenously with cationic lipid:pDNA complexes develop significant, dose-dependent hematologic and serologic changes typified by profound leukopenia, thrombocytopenia, and elevated levels of serum transaminases indicative of hepatocellular necrosis. Vector administration also induced a potent inflammatory response characterized by complement activation and the induction of the cytokines IFN-gamma, TNF-alpha, IL-6, and IL-12. These toxicities were found to be transient, resolving with different kinetics to pretreatment levels by 14 days posttreatment. The toxic syndrome observed was independent of the cationic lipid:pDNA ratio, the cationic lipid species, and the level of transgene expression attained. Mechanistic studies determined that neither the complement cascade nor TNF-alpha were key mediators in the development of these characteristic toxicities. Administration of equivalent doses of the individual vector components revealed that cationic liposomes or pDNA alone did not generate the toxic responses observed with cationic lipid:pDNA complexes. Only moderate leukopenia was associated with administration of cationic liposomes or pDNA alone, while only mild thrombocytopenia was noted in pDNA-treated animals. These results establish a panel of objective parameters that can be used to quantify the acute toxicities resulting from systemic administration of cationic lipid:pDNA complexes, which in turn provides a means to compare the therapeutic indices of these vectors.

Functional hyposplenism following allogeneic bone marrow transplantation.

AIMS: To investigate the incidence of functional hyposplenism in a group of patients who had undergone allogeneic bone marrow transplantation (BMT). METHODS: Splenic function was assessed by counting the number of gluteraldehyde fixed red blood cells containing pits or indentations as examined by interference phase microscopy. Normal values are < 2% whereas splenectomy patients have values of 25 to 40%. RESULTS: Twenty eight BMT recipients (17 men, 11 women) were studied at varying periods post-transplant and the results compared with 20 healthy volunteers and 10 patients who had undergone splenectomy or had splenic atrophy because of haematological conditions. Of the 28 BMT recipients, one had undergone a prior splenectomy; of the remaining 27 patients, four (15%) had evidence of functional hyposplenism with between 5.0 and 34.0% pitted cells. Of these four patients, one had active extensive chronic graft versus host disease (GvHD) which has been previously reported to be associated with functional hyposplenism following transplantation. Only one of the four patients had peripheral blood red cell changes typical of hyposplenism. CONCLUSION: These results confirm that extensive chronic GvHD is associated with hyposplenism. Intermediate degrees of functional hyposplenism may also occur following BMT in the absence of chronic GvHD and in the absence of haematological features of hyposplenism on routine blood films. This may be of significance in mediating the susceptibility to infection with encapsulating bacteria seen following allogeneic BMT.

Music perception and cerebral asymmetries.

Six experiments investigated the detection of pitch, rhythm and harmony changes in music perception. While RTs did not differentiate between ears for detecting a changed note in either a single line melody or a five note whole tone sequence, the right ear was more accurate. The left ear was faster, and the right more accurate in detecting rhythm changes in a five note sequence. The ears did not differ in detecting harmony changes. Finally, the right ear proved consistently more sensitive (d') in recognizing excerpts from unfamiliar melodies, and except only for female nonmusicians, the left ear was more sensitive for familiar melodies. If the adoption of differintial listening strategies determines the direction of laterality differences such as these, then familiarity also seems important in determining listening strategies.

Measurement of pulsatile flow using MRI and a Bayesian technique of probability analysis.

This work shows that complete spatial information of periodic pulsatile fluid flows can be rapidly obtained by Bayesian probability analysis of flow encoded magnetic resonance imaging data. These data were acquired as a set of two-dimensional images (complete two-dimensional sampling of k-space or reciprocal position space) but with a sparse (six point) and nonuniform sampling of q-space or reciprocal displacement space. This approach enables more precise calculation of fluid velocity to be achieved than by conventional two q-sample phase encoding of velocities, without the significant time disadvantage associated with the complete flow measurement required for Fourier velocity imaging. For experimental comparison with the Bayesian analysis applied to nonuniformly sampled q-space data, a Fourier velocity imaging technique was used with one-dimensional spatial encoding within a selected slice and a uniform sampling of q-space using 64 values of the pulsed gradients to encode fluid flow. Because the pulsatile flows were axially symmetric within the resolution of the experiment, the radial variation of fluid velocity, in the direction of the pulsed gradients, was reconstructed from one-dimensional spatial projections of the velocity by exploiting the central slice theorem. Data were analysed for internal consistency using linearised flow theories. The results show that nonuniform q-space sampling followed by Bayesian probability analysis is at least as accurate as the combined uniform q-space sampling with Fourier velocity imaging and projection reconstruction method. Both techniques give smaller errors than a two-point sampling of q-space (the conventional flow encoding experiment).

Murine ovulatory response to ultrasound exposure and its gynecological relevance.

Ultrasonographic assessment of ovarian follicular maturity was reportedly associated with atypically early ovulation in women; related studies reported reduced litter sizes in rats. To confirm these findings, mice which were midway between ovulatory gonadotropin (LH or human chorionic gonadotropin) stimulation and ovulation, were sham- or ultrasound-treated periovarially for 5 min. Exposure was at a spatial average, temporal maximum intensity of 60 W/cm2. Carrier frequency in the pulse was 2.2 MHz, pulse length was 10 microseconds, and pulse repetition frequency was 200 Hz. Spatial average, temporal average intensity was 0.12 W/cm2. At autopsy, ultrasound- and sham-treated groups responded similarly in proportions ovulating and in mean ova ovulated. Combined experiments had a 97% chance of detecting a significant (greater than 1 h) advance in ovulation time, had it occurred. Thus, our adequately sensitive mammalian ovulatory tests revealed no association of ultrasound with decrease in ovum number or acceleration in ovulation time (as reported in humans).

Testing for the teratogenicity of pulsed ultrasound in mice.

Our replicate of a study by Takabayashi et al. (1981) Effects of pulse-wave ultrasonic irradiation on mouse embryo. Cho-Onpa Igaku (Supersonic Medicine) 8, 286-288 failed to show any effects of exposure in utero of mice to spatial average, temporal maximum intensities of 60 W/cm2. Fetuses were exposed at 8 days post fertilization and assessed at 18 days for fetal weight, resorptions, premature deaths, and malformations. Carrier frequency in the pulse was 2 MHz. Pulse lengths of 10 microseconds and pulse repetition frequencies of 1000 and 200 Hz yielded spatial average, temporal average intensities of 0.6 and 0.1 W/cm2. Total exposure time was 5 min. Our results provide no basis to conclude that conditions relevant to human fetal monitoring will cause developmental, externally visible anomalies in mice exposed as 8-day fetuses.

Pulsed ultrasound and the hyperbarically exposed mouse fetus.

To enhance the likelihood of cavitation, pregnant mice were subjected to hyperbaric conditions and quickly returned to atmospheric pressure. Following this treatment, they were exposed to spatial average, pulse average intensities of 100 W/cm2 (2.2-MHz, 20-microseconds pulses with a duty cycle of 1/1000 or a temporal average spatial average intensity of 0.1 W/cm2). Fetal weights, deaths and malformations were scored. No statistically significant effects were observed in the offspring.

A test of I2t as a dose parameter for fetal weight reduction from exposure to ultrasound.

It has been suggested that fetal weight reduction by ultrasound exposure is linearly related to the dose parameter I2t, where I is the intensity and t the exposure time. A direct test of the concept was conducted using CF-1 mice. No effect on fetal weight was found at values of the dose parameter large enough to produce measurable heating in the fetal and maternal tissues.

Predicting service utilization with the Child and Adolescent Functional Assessment Scale in a sample of youths with serious emotional disturbance served by center for mental health services-funded demonstrations.

This study investigated level of restrictiveness of living arrangements and number of days in out-of-family care at six months postintake, based on the Child and Adolescent Functional Assessment Scale (CAFAS), the Child Behavior Checklist (CBCL), gender, age, and level of family income at intake. It was composed of youths who met the criteria for serious emotional disturbance (SED) and were for the most part living in families that are described as socioeconomically disadvantaged. A multinomial logit model was used in the analysis of level of restrictiveness of living arrangements, and an ordinary least squares (OLS) regression model was conducted on number of days in out-of-family care. The CAFAS score at intake was found to be a significant predictor of service utilization between intake and six months and was a more consistent predictor than the CBCL. Results suggest that the CAFAS can be used to match service needs with resource allocation and to monitor performance-based outcome indicators.

The immune response to vaccinia virus is significantly reduced after scarification with TK- recombinants as compared to wild-type virus.

Although it is unlikely that large-scale vaccination against smallpox will ever be required again, it is conceivable that the need may arise to vaccinate against a human orthopoxvirus infection. A possible example could be the emergence of monkey poxvirus (MPV) as a significant human disease in Africa. Vaccinia virus (VV) recombinants, genetically modified to carry the immunogenic proteins of other pathogenic organisms, have potential use as vaccines against other diseases present in this region. The immune response to parental wild-type (wt) or recombinant VV was examined by binding and functional assays, relevant to protection: total IgG, IgG subclass profile, B5R gene product (gp42)-specific IgG, neutralizing antibodies and class 1-mediated cytotoxic lymphocyte activity. There was a substantial reduction in the immune response to VV after scarification with about 10(8) PFU of recombinant as compared to wt virus. These data suggest that to achieve the levels of immunity associated with protection against human orthopoxvirus infection, and to control a possible future outbreak of orthopoxvirus disease, the use of wt VV would be necessary.