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Find video protocols related to scientific articles indexed in Pubmed.
Intravenously Injected Human Apolipoprotein A-I Rapidly Enters the Central Nervous System via the Choroid Plexus.
J Am Heart Assoc
PUBLISHED: 11-14-2014
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Brain lipoprotein metabolism is dependent on lipoprotein particles that resemble plasma high-density lipoproteins but that contain apolipoprotein (apo) E rather than apoA-I as their primary protein component. Astrocytes and microglia secrete apoE but not apoA-I; however, apoA-I is detectable in both cerebrospinal fluid and brain tissue lysates. The route by which plasma apoA-I enters the central nervous system is unknown.
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A risk prediction model for smoking experimentation in Mexican American youth.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 07-25-2014
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Smoking experimentation in Mexican American youth is problematic. In light of the research showing that preventing smoking experimentation is a valid strategy for smoking prevention, there is a need to identify Mexican American youth at high risk for experimentation.
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LCAT deficiency does not impair amyloid metabolism in APP/PS1 mice.
J. Lipid Res.
PUBLISHED: 06-20-2014
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A key step in plasma HDL maturation from discoidal to spherical particles is the esterification of cholesterol to cholesteryl ester, which is catalyzed by LCAT. HDL-like lipoproteins in cerebrospinal fluid (CSF) are also spherical, whereas nascent lipoprotein particles secreted from astrocytes are discoidal, suggesting that LCAT may play a similar role in the CNS. In plasma, apoA-I is the main LCAT activator, while in the CNS, it is believed to be apoE. apoE is directly involved in the pathological progression of Alzheimer's disease, including facilitating ?-amyloid (A?) clearance from the brain, a function that requires its lipidation by ABCA1. However, whether apoE particle maturation by LCAT is also required for A? clearance is unknown. Here we characterized the impact of LCAT deficiency on CNS lipoprotein metabolism and amyloid pathology. Deletion of LCAT from APP/PS1 mice resulted in a pronounced decrease of apoA-I in plasma that was paralleled by decreased apoA-I levels in CSF and brain tissue, whereas apoE levels were unaffected. Furthermore, LCAT deficiency did not increase A? or amyloid in APP/PS1 LCAT(-/-) mice. Finally, LCAT expression and plasma activity were unaffected by age or the onset of Alzheimer's-like pathology in APP/PS1 mice. Taken together, these results suggest that apoE-containing discoidal HDLs do not require LCAT-dependent maturation to mediate efficient A? clearance.
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Genetic, psychosocial, and demographic factors associated with social disinhibition in Mexican-origin youth.
Brain Behav
PUBLISHED: 05-16-2014
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The genetic heritability for sensation-seeking tendencies ranges from 40 to 60%. Sensation-seeking behaviors typically manifest during adolescence and are associated with alcohol and cigarette experimentation in adolescents. Social disinhibition is an aspect of sensation-seeking that is closely tied to cigarette and alcohol experimentation.
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Touchscreen performance and knowledge transfer in the red-footed tortoise (Chelonoidis carbonaria).
Behav. Processes
PUBLISHED: 04-29-2014
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In recent years red-footed tortoises have been shown to be proficient in a number of spatial cognition tasks that involve movement of the animal through space (e.g., the radial maze). The present study investigated the ability of the tortoise to learn a spatial task in which the response required was simply to touch a stimulus presented in a given position on a touchscreen. We also investigated the relation between this task and performance in a different spatial task (an arena, in which whole-body movement was required). Four red-footed tortoises learned to operate the touchscreen apparatus, and two learned the simple spatial discrimination. The side-preference trained with the touchscreen was maintained when behaviour was tested in a physical arena. When the contingencies in the arena were then reversed, the tortoises learned the reversal but in a subsequent test did not transfer it to the touchscreen. Rather they chose the side that had been rewarded originally on the touchscreen. The results show that red-footed tortoises are able to operate a touchscreen and can successfully solve a spatial two-choice task in this apparatus. There was some indication that the preference established with the touchscreen could transfer to an arena, but with subsequent training in the arena independent patterns of choice were established that could be evoked according to the test context.
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Social learning by imitation in a reptile (Pogona vitticeps).
Anim Cogn
PUBLISHED: 02-26-2014
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The ability to learn through imitation is thought to be the basis of cultural transmission and was long considered a distinctive characteristic of humans. There is now evidence that both mammals and birds are capable of imitation. However, nothing is known about these abilities in the third amniotic class-reptiles. Here, we use a bidirectional control procedure to show that a reptile species, the bearded dragon (Pogona vitticeps), is capable of social learning that cannot be explained by simple mechanisms such as local enhancement or goal emulation. Subjects in the experimental group opened a trap door to the side that had been demonstrated, while subjects in the ghost control group, who observed the door move without the intervention of a conspecific, were unsuccessful. This, together with differences in behaviour between experimental and control groups, provides compelling evidence that reptiles possess cognitive abilities that are comparable to those observed in mammals and birds and suggests that learning by imitation is likely to be based on ancient mechanisms.
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The impact of personalized risk feedback on Mexican Americans' perceived risk for heart disease and diabetes.
Health Educ Res
PUBLISHED: 01-24-2014
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Little is known about the effect of personalized risk information on risk perceptions over time, particularly among ethnically diverse subpopulations. The present study examines Mexican American's (MAs) risk perceptions for heart disease and diabetes at baseline and following receipt of risk feedback based on family health history. Participants comprising 162 households received a pedigree or personalized risk feedback, with or without behavioral risk reduction recommendations. Multiple logistic regression analyses were used to assess lifetime perceived risk (LPR) at baseline, 3 months and 10 months following the receipt of risk feedback. Having an elevated familial risk of heart disease or diabetes increased the odds of an elevated LPR for both diseases at baseline. At 3 months, compared with receipt of a pedigree only, MAs receiving elevated risk feedback for both diseases were more likely to have an elevated LPR for both diseases. At 10 months, participants receiving weak risk feedback for both diseases indicated an adjustment to a lower LPR for heart disease only. Results suggest that communicating risk for multiple diseases may be more effective than a single disease, with responses to increased risk feedback more immediate than to weak risk feedback.
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Acute management of skin tears: a change in practice pilot study.
Int Wound J
PUBLISHED: 01-03-2014
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Skin tears are an increasingly common injury occurring in the elderly population and have significant associated morbidity secondary to poor wound healing, prolonged hospital stays and reduced mobility. There has been a shift in practice for the acute management of skin tears within our institution, which has resulted in improved outcomes and reduced morbidity for this common and debilitating injury. Review of past and current practices including cost analyses has led to the establishment of a management protocol for the hospital and wider area health service with the aim to reduce the burden of disease amongst our ever-expanding elderly population.
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Hormonal modulators of glial ABCA1 and apoE levels.
J. Lipid Res.
PUBLISHED: 09-02-2013
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Apolipoprotein E (apoE) is the major lipid carrier in the central nervous system. As apoE plays a major role in the pathogenesis of Alzheimer disease (AD) and also mediates repair pathways after several forms of acute brain injury, modulating the expression, secretion, or function of apoE may provide potential therapeutic approaches for several neurological disorders. Here we show that progesterone and a synthetic progestin, lynestrenol, significantly induce apoE secretion from human CCF-STTG1 astrocytoma cells, whereas estrogens and the progesterone metabolite allopregnanolone have negligible effects. Intriguingly, lynestrenol also increases expression of the cholesterol transporter ABCA1 in CCF-STTG1 astrocytoma cells, primary murine glia, and immortalized murine astrocytes that express human apoE3. The progesterone receptor inhibitor RU486 attenuates the effect of progestins on apoE expression in CCF-STTG1 astrocytoma cells but has no effect on ABCA1 expression in all glial cell models tested, suggesting that the progesterone receptor (PR) may participate in apoE but does not affect ABCA1 regulation. These results suggest that selective reproductive steroid hormones have the potential to influence glial lipid homeostasis through liver X receptor-dependent and progesterone receptor-dependent pathways.
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Intergenerational Transfer of Smoking Across Three Generations and Forty-five Years.
Nicotine Tob. Res.
PUBLISHED: 08-13-2013
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Although many have examined the linkages between smoking behaviors across 2 generations, few have examined these linkages among 3 generations.
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Is rectal gonorrhoea a lead indicator of HIV transmission among men who have sex with men in Victoria, Australia?
Sex Health
PUBLISHED: 04-16-2013
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Objectives To examine whether rectal gonorrhoea (RG; Neisseria gonorrhoeae) can be used as a lead indicator of trends in HIV diagnosis in men who have sex with men (MSM). Methods: Data from a metropolitan sexual health centre in Victoria, Australia, on RG and HIV tests in HIV-negative MSM from January 2006 to December 2011 were examined. Results: Allowing RG a 12-month lead over HIV showed no concordance in proportion positive (r=0.27; P-value=0.28). Conclusions: The data do not support use of RG trends as a lead indicator of trends in HIV among MSM.
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Pigeons discriminate objects on the basis of abstract familiarity.
Anim Cogn
PUBLISHED: 04-05-2013
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Knowledge of previous encounters with conspecifics is thought to be beneficial as it allows fast and appropriate behavioral responses toward those animals. This level of categorization goes beyond perceptual similarity and requires the individual to refer to a more abstract common referent, namely familiarity. It has been shown that pigeons are able to form functional classes of conspecifics that are based on familiarity. To date, we do not know whether this ability is restricted to the social context (including heterospecifics) or if it can also be used to classify inanimate objects. Furthermore, the factors influencing the formation of this functional class are still unknown. Here, we show that pigeons (Columba livia) are able to use a categorical rule of familiarity to classify previously unseen photographs of objects from their living environment. Pigeons that lacked real-life experience with the objects were not able to do so. This suggests that perceptual features alone were not sufficient for class recognition. To investigate the impact of additional functional properties of the objects, familiar objects were further divided into two subcategories, namely those that were considered functionally relevant to the birds and those that were not. Although the majority of pigeons learned to categorize photographs of objects based on familiarity alone, our results also suggest an unlearned preference for "relevant" familiar objects. The results presented here suggest that pigeons are able to learn to extract the discriminative feature of abstract familiarity from pictures by referring to previous real-life experience but that additional functions of objects lead to a preference of these objects.
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The associations of body image, anxiety, and smoking among Mexican-origin youth.
J Adolesc Health
PUBLISHED: 03-19-2013
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Among Mexican-origin teenagers, anxiety is associated with cigarette experimentation, while among girls and young women from other ethnic groups the desire to be thin is associated with smoking. However, little is known about the associations of body image concerns with smoking in Mexican-origin youth, particularly when accounting for anxiety.
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The liver X receptor agonist GW3965 improves recovery from mild repetitive traumatic brain injury in mice partly through apolipoprotein E.
PLoS ONE
PUBLISHED: 01-17-2013
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Traumatic brain injury (TBI) increases Alzheimers disease (AD) risk and leads to the deposition of neurofibrillary tangles and amyloid deposits similar to those found in AD. Agonists of Liver X receptors (LXRs), which regulate the expression of many genes involved in lipid homeostasis and inflammation, improve cognition and reduce neuropathology in AD mice. One pathway by which LXR agonists exert their beneficial effects is through ATP-binding cassette transporter A1 (ABCA1)-mediated lipid transport onto apolipoprotein E (apoE). To test the therapeutic utility of this pathway for TBI, we subjected male wild-type (WT) and apoE-/- mice to mild repetitive traumatic brain injury (mrTBI) followed by treatment with vehicle or the LXR agonist GW3965 at 15 mg/kg/day. GW3965 treatment restored impaired novel object recognition memory in WT but not apoE-/- mice. GW3965 did not significantly enhance the spontaneous recovery of motor deficits observed in all groups. Total soluble A?(40) and A?(42) levels were significantly elevated in WT and apoE-/- mice after injury, a response that was suppressed by GW3965 in both genotypes. WT mice showed mild but significant axonal damage at 2 d post-mrTBI, which was suppressed by GW3965. In contrast, apoE-/- mice showed severe axonal damage from 2 to 14 d after mrTBI that was unresponsive to GW3965. Because our mrTBI model does not produce significant inflammation, the beneficial effects of GW3965 we observed are unlikely to be related to reduced inflammation. Rather, our results suggest that both apoE-dependent and apoE-independent pathways contribute to the ability of GW3965 to promote recovery from mrTBI.
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Cigarette experimentation and the population attributable fraction for associated genetic and non-genetic risk factors.
PLoS ONE
PUBLISHED: 01-16-2013
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We, and others, have shown that experimenting with cigarettes is a function of both non-genetic and genetic factors. In this analysis we ask: how much of the total risk of experimenting with cigarettes, among those who had not experimented with cigarettes when they enrolled in a prospective cohort, is attributable to genetic factors and to non-genetic factors?
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Cigarette experimentation in Mexican origin youth: psychosocial and genetic determinants.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 10-25-2011
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Established psychosocial risk factors increase the risk for experimentation among Mexican origin youth. Now, we comprehensively investigate the added contribution of select polymorphisms in candidate genetic pathways associated with sensation seeking, risk taking, and smoking phenotypes to predict experimentation.
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Gender differences in sociodemographic and behavioral influences of physical activity in Mexican-origin adolescents.
J Phys Act Health
PUBLISHED: 08-02-2011
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Understanding the factors that contribute to physical activity (PA) in Mexican-origin adolescents is essential to the design of effective efforts to enhance PA participation in this population.
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An ABCA1-independent pathway for recycling a poorly lipidated 8.1 nm apolipoprotein E particle from glia.
J. Lipid Res.
PUBLISHED: 06-26-2011
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Lipid transport in the brain is coordinated by glial-derived lipoproteins that contain apolipoprotein E (apoE) as their primary protein. Here we show that apoE is secreted from wild-type (WT) primary murine mixed glia as nascent lipoprotein subspecies ranging from 7.5 to 17 nm in diameter. Negative-staining electron microscropy (EM) revealed rouleaux, suggesting a discoidal structure. Potassium bromide (KBr) density gradient ultracentrifugation showed that all subspecies, except an 8.1 nm particle, were lipidated. Glia lacking the cholesterol transporter ABCA1 secreted only 8.1 nm particles, which were poorly lipidated and nondiscoidal but could accept lipids to form the full repertoire of WT apoE particles. Receptor-associated-protein (RAP)-mediated inhibition of apoE receptor function blocked appearance of the 8.1 nm species, suggesting that this particle may arise through apoE recycling. Selective deletion of the LDL receptor (LDLR) reduced the level of 8.1 nm particle production by approximately 90%, suggesting that apoE is preferentially recycled through the LDLR. Finally, apoA-I stimulated secretion of 8.1 nm particles in a dose-dependent manner. These results suggest that nascent glial apoE lipoproteins are secreted through multiple pathways and that a greater understanding of these mechanisms may be relevant to several neurological disorders.
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The LXR agonist GW3965 increases apoA-I protein levels in the central nervous system independent of ABCA1.
Biochim. Biophys. Acta
PUBLISHED: 06-24-2011
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Lipoprotein metabolism in the central nervous system (CNS) is based on high-density lipoprotein-like particles that use apoE as their predominant apolipoprotein rather than apoA-I. Although apoA-I is not expressed in astrocytes and microglia, which produce CNS apoE, apoA-I is reported to be expressed in porcine brain capillary endothelial cells and also crosses the blood-brain barrier (BBB). These mechanisms allow apoA-I to reach concentrations in cerebrospinal fluid (CSF) that are approximately 0.5% of its plasma levels. Recently, apoA-I has been shown to enhance cognitive function and reduce cerebrovascular amyloid deposition in Alzheimers Disease (AD) mice, raising questions about the regulation and function of apoA-I in the CNS. Peripheral apoA-I metabolism is highly influenced by ABCA1, but less is known about how ABCA1 regulates CNS apoA-I. We report that ABCA1 deficiency leads to greater retention of apoA-I in the CNS than in the periphery. Additionally, treatment of symptomatic AD mice with GW3965, an LXR agonist that stimulates ABCA1 expression, increases apoA-I more dramatically in the CNS compared to the periphery. Furthermore, GW3965-mediated up-regulation of CNS apoA-I is independent of ABCA1. Our results suggest that apoA-I may be regulated by distinct mechanisms on either side of the BBB and that apoA-I may serve to integrate peripheral and CNS lipid metabolism. This article is part of a Special Issue entitled Advances in High Density Lipoprotein Formation and Metabolism: A Tribute to John F. Oram (1945-2010).
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The advantage of imputation of missing income data to evaluate the association between income and self-reported health status (SRH) in a Mexican American cohort study.
J Immigr Minor Health
PUBLISHED: 05-28-2011
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Missing data often occur in cross-sectional surveys and longitudinal and experimental studies. The purpose of this study was to compare the prediction of self-rated health (SRH), a robust predictor of morbidity and mortality among diverse populations, before and after imputation of the missing variable "yearly household income." We reviewed data from 4,162 participants of Mexican origin recruited from July 1, 2002, through December 31, 2005, and who were enrolled in a population-based cohort study. Missing yearly income data were imputed using three different single imputation methods and one multiple imputation under a Bayesian approach. Of 4,162 participants, 3,121 were randomly assigned to a training set (to derive the yearly income imputation methods and develop the health-outcome prediction models) and 1,041 to a testing set (to compare the areas under the curve (AUC) of the receiver-operating characteristic of the resulting health-outcome prediction models). The discriminatory powers of the SRH prediction models were good (range, 69-72%) and compared to the prediction model obtained after no imputation of missing yearly income, all other imputation methods improved the prediction of SRH (P < 0.05 for all comparisons) with the AUC for the model after multiple imputation being the highest (AUC = 0.731). Furthermore, given that yearly income was imputed using multiple imputation, the odds of SRH as good or better increased by 11% for each $5,000 increment in yearly income. This study showed that although imputation of missing data for a key predictor variable can improve a risk health-outcome prediction model, further work is needed to illuminate the risk factors associated with SRH.
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Factors that influence mammography use and breast cancer detection among Mexican-American and African-American women.
Cancer Causes Control
PUBLISHED: 05-03-2011
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This study examined factors that influence mammography use and breast cancer detection, including education, health insurance, and acculturation, among Mexican-American (MA) and African-American (AA) women.
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Sensation seeking, risk behaviors, and alcohol consumption among Mexican origin youth.
J Adolesc Health
PUBLISHED: 04-09-2011
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To examine factors associated with ever use of alcohol among Mexican origin youth.
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Psychosocial risk and correlates of early menarche in Mexican-American girls.
Am. J. Epidemiol.
PUBLISHED: 03-31-2011
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Mexican-American girls have one of the fastest rates of decline in age at menarche. To date, no study has addressed the role of psychosocial factors on age at menarche in this population. Using data from a longitudinal cohort of Mexican-American girls from the Houston, Texas, metropolitan area recruited in 2005, the authors investigated associations between family life and socioeconomic environment and age at menarche in 523 girls. After adjusting for maternal age at menarche, daughters age, and body mass index at baseline, perception of family life environment as conflict-prone was significantly associated with an earlier age at menarche (< 11 years). Additionally, there was a 2-fold higher risk (odds ratio = 2.22, 95% confidence interval: 1.12, 4.40) of early menarche among daughters of mothers who were single parents compared with those who were not. Furthermore, girls who matured early had a 2.5-fold increased risk (odds ratio = 2.69, 95% confidence interval: 1.04, 6.96) of experimenting with cigarettes compared with those who had an average-to-late age at menarche (? 11 years). This study provides important information regarding the role of family life environment and single parenting on age at menarche in Mexican Americans. Awareness of the impact of the family life environment and fathers absence during the early years should be emphasized when addressing early age at menarche across cultures.
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Policy implications of early onset breast cancer among Mexican-origin women.
Cancer
PUBLISHED: 02-15-2011
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Overall, Latinas are more likely to be diagnosed with a more advanced stage of breast cancer and are 20% more likely to die of breast cancer than non-Hispanic white women. It is estimated that from 2003 to 2006, $82.0 billion in direct medical care expenditures, in addition to 100,000 lives annually, could be saved by eliminating health disparities experienced by Latinos and increasing the use of up to 5 preventive services in the United States. An additional 3700 lives could be saved if 90% of women aged ?40 years were recently screened for breast cancer.
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Willingness of Mexican-American adults to share family health history with healthcare providers.
Am J Prev Med
PUBLISHED: 02-03-2011
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Collecting family health history (FHH) information to share with healthcare providers is an important aspect of health-risk assessment.
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Patterns of reporting health-related quality of life outcomes in randomized clinical trials: implications for clinicians and quality of life researchers.
Qual Life Res
PUBLISHED: 11-02-2010
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To assess the patterns of, and trends over time in, health-related quality of life (HRQL) reporting in randomized controlled trials (RCTs).
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ATP-binding cassette transporter A1 mediates the beneficial effects of the liver X receptor agonist GW3965 on object recognition memory and amyloid burden in amyloid precursor protein/presenilin 1 mice.
J. Biol. Chem.
PUBLISHED: 08-25-2010
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The cholesterol transporter ATP-binding cassette transporter A1 (ABCA1) moves lipids onto apolipoproteins including apolipoprotein E (apoE), which is the major cholesterol carrier in the brain and an established genetic risk factor for late-onset Alzheimer disease (AD). In amyloid mouse models of AD, ABCA1 deficiency exacerbates amyloidogenesis, whereas ABCA1 overexpression ameliorates amyloid load, suggesting a role for ABCA1 in A? metabolism. Agonists of liver X receptors (LXR), including GW3965, induce transcription of several genes including ABCA1 and apoE, and reduce A? levels and improve cognition in AD mice. However, the specific role of ABCA1 in mediating beneficial responses to LXR agonists in AD mice is unknown. We evaluated behavioral and neuropathogical outcomes in GW3965-treated female APP/PS1 mice with and without ABCA1. Treatment of APP/PS1 mice with GW3965 increased ABCA1 and apoE protein levels. ABCA1 was required to observe significantly elevated apoE levels in brain tissue and cerebrospinal fluid upon therapeutic (33 mg/kg/day) GW3965 treatment. At 33 mg/kg/day, GW3965 was also associated with a trend toward redistribution of A? to the carbonate-soluble pool independent of ABCA1. APP/PS1 mice treated with either 2.5 or 33 mg/kg/day of GW3965 showed a clear trend toward reduced amyloid burden in hippocampus and whole brain, whereas APP/PS1-treated mice lacking ABCA1 failed to display reduced amyloid load in the whole brain and showed trends toward increased hippocampal amyloid. Treatment of APP/PS1 mice with either dose of GW3965 completely restored novel object recognition memory to wild-type levels, which required ABCA1. These results suggest that ABCA1 contributes to several beneficial effects of the LXR agonist GW3965 in APP/PS1 mice.
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Mediating effects of smoking and chronic obstructive pulmonary disease on the relation between the CHRNA5-A3 genetic locus and lung cancer risk.
Cancer
PUBLISHED: 06-22-2010
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Recent genome-wide association studies of lung cancer have shown that the CHRNA5-A3 region on chromosome 15q24-25.1 is strongly associated with an increased risk of lung cancer and nicotine dependence, and is thought to be associated with chronic obstructive pulmonary disease as well. However, it has not been established whether the association between genetic variants and lung cancer risk is a direct one or one mediated by nicotine dependence.
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Intraspecific diversity regulates fungal productivity and respiration.
PLoS ONE
PUBLISHED: 06-17-2010
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Individuals and not just species are key components of biodiversity, yet the relationship between intraspecific diversity and ecosystem functioning in microbial systems remains largely untested. This limits our ability to understand and predict the effects of altered genetic diversity in regulating key ecosystem processes and functions. Here, we use a model fungal system to test the hypothesis that intraspecific genotypic richness of Paxillus obscurosporus stimulates biomass and CO(2) efflux, but that this is dependent on nitrogen supply. Using controlled experimental microcosms, we show that populations containing several genotypes (maximum 8) of the fungus had greater productivity and produced significantly more CO(2) than those with fewer genotypes. Moreover, intraspecific diversity had a much stronger effect than a four-fold manipulation of the carbon:nitrogen ratio of the growth medium. The effects of intraspecific diversity were underpinned by strong roles of individuals, but overall intraspecific diversity increased the propensity of populations to over-yield, indicating that both complementarity and selection effects can operate within species. Our data demonstrate the importance of intraspecific diversity over a range of nitrogen concentrations, and the need to consider fine scale phylogenetic information of microbial communities in understanding their contribution to ecosystem processes.
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Extant health behaviors and uptake of standardized vs tailored health messages among cancer survivors enrolled in the FRESH START trial: a comparison of fighting-spirits vs fatalists.
Psychooncology
PUBLISHED: 06-11-2010
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Cancer coping styles have been associated with several cancer-related outcomes. We examined whether baseline lifestyle behaviors differed between cancer survivors with fatalistic vs fighting-spirit coping styles, and whether there was differential response to two diet-exercise mailed-print interventions, one standardized and another individually tailored.
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Tracking and capture of constant and varying velocity stimuli: a cross-species comparison of pigeons and humans.
Anim Cogn
PUBLISHED: 05-06-2010
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The mechanisms underlying tracking and capture of moving objects in non-human animals are poorly understood. This set of experiments sought to further explore aspects of anticipatory tracking in pigeons and to conduct comparisons with human participants. In Experiment 1a, pigeons were presented with two types of varying velocities (fast-slow-fast or slow-fast-slow) in separate phases. They were readily able to track and anticipate both of these motion types. To examine the effects of predictability on anticipatory tracking, Experiment 1b presented the pigeons with the same two varying velocities randomly intermixed within a session. This resulted in reduced capture success, later capture, and errors that no longer anticipated ahead of the motion, suggesting that the anticipatory mechanism had been disrupted. This implies that the mechanisms involved in pigeon tracking are different from the predictive extrapolation mechanism proposed in humans. Experiment 2 tested this by presenting adult humans with a tracking task that was similar to tasks previously received by the pigeons. The capture behavior of humans was similar to the pigeons, but the errors revealed different processes underlying their tracking behavior.
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Social learning in a non-social reptile (Geochelone carbonaria).
Biol. Lett.
PUBLISHED: 03-31-2010
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The ability to learn from the actions of another is adaptive, as it is a shortcut for acquiring new information. However, the evolutionary origins of this trait are still unclear. There is evidence that group-living mammals, birds, fishes and insects can learn through observation, but this has never been investigated in reptiles. Here, we show that the non-social red-footed tortoise (Geochelone carbonaria) can learn from the actions of a conspecific in a detour task; non-observer animals (without a conspecific demonstrator) failed. This result provides the first evidence that a non-social species can use social cues to solve a task that it cannot solve through individual learning, challenging the idea that social learning is an adaptation for social living.
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Motivation for health screening: evaluation of social influence among Mexican-American adults.
Am J Prev Med
PUBLISHED: 03-24-2010
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Americans of Mexican origin are at high risk for developing cardiovascular disease.
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Gaze following in the red-footed tortoise (Geochelone carbonaria).
Anim Cogn
PUBLISHED: 01-20-2010
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Gaze following refers to the ability of an animal to orient its gaze direction to that of another organism. Such a behavior may be adaptive as it alerts the observer to important objects in the environment such as food or predators. This behavior has been shown in mammals and birds, but the evolutionary history and the distribution of this behavior throughout the animal kingdom remain unclear. Here, we show that a reptile, the red-footed tortoise (Geochelone carbonaria), is able to follow the gaze of a conspecific in a lookup task. Controls revealed that neither the mere presence of a conspecific nor the presentation of a light stimulus (without a demonstrator present) controlled the tortoises behavior. The findings indicate that the ability to follow gaze may be found in mammals, birds and reptiles and could have evolved before the amniotic line diverged, or may result from a general ability to learn.
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Cognitive susceptibility to smoking: Two paths to experimenting among Mexican origin youth.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 12-05-2009
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Cognitive susceptibility to smoking, defined as the lack of a firm commitment not to smoke in the future or if offered a cigarette by a friend, begins in childhood and is an early phase in the transition from never to ever smoking. Our objectives were to examine susceptibility to smoking and other psychosocial risk factors for experimentation with cigarettes among Mexican origin adolescents and to determine whether susceptibility status moderates the relationship between established risk factors for experimentation with cigarettes and future experimentation. We examined susceptibility and several psychosocial factors associated with susceptibility as baseline predictors of experimentation after 3 years of follow-up among 964 Mexican origin girls and boys between 11 and 13 years of age from the Houston metropolitan area. Participants were recruited between May 2005 and October 2006 and reported that they had never experimented with cigarettes at baseline. Baseline susceptibility and experimentation rates were 23% and 9%, respectively, whereas the follow-up experimentation rate, among those who had not experimented at baseline, was 22%. Susceptible adolescents at baseline were 2.6 times more likely to have experimented with cigarettes by follow-up. Baseline susceptibility moderated the relationship between experimentation at follow-up and the psychosocial risk factors assessed at baseline. Susceptibility is a valid and strong marker for the transition to experimentation for Mexican origin adolescents. Our results suggest that tailoring primary prevention programs by a youths susceptibility status may increase the efficacy of prevention efforts among Mexican origin youth.
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Exposure to smoking imagery in the movies and experimenting with cigarettes among Mexican heritage youth.
Cancer Epidemiol. Biomarkers Prev.
PUBLISHED: 12-05-2009
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There is growing evidence that an adolescents decision to try cigarettes is influenced by level of exposure to movies in which smoking is portrayed. Less is known about how ethnicity affects this process. We examined whether acculturation and/or country of birth influence the relationship between exposure to smoking imagery in the movies and experimenting with cigarettes among Mexican origin youth. We prospectively followed 1,328 Mexican origin adolescents ages 11 to 13 years at baseline. We assessed which of 50 movies (randomly selected from a pool of 250 popular contemporary movies released from 1999 to 2004 and content analyzed for smoking) adolescents had seen. Smoking behavior was assessed at baseline and at 6-month intervals over 24 months. Ten percent of the adolescents had experimented at baseline; 17% tried subsequently. Multivariate analyses revealed, as exposure to smoking imagery in the movies increased, the chances of having ever experimented [adjusted odds ratio (AOR) = 1.27; 95% confidence interval (CI), 1.10-1.48] and of being a new experimenter (AOR = 1.19; 95% CI, 1.01-1.40) increased, equivalent to a 4.2% increased risk of ever and a 3.0% increased risk of new experimenting for each additional quartile of movie exposure. This effect was moderated by country of birth. For Mexican-born youth, exposure to smoking imagery in the movies was the strongest independent predictor of new experimentation (AOR = 1.52; 95% CI, 1.14-2.05). For U.S.-born youth, we observed a ceiling effect: the percent of experimenters increased with increasing exposure, and then flattened. Among Mexican-born youth, exposure to smoking imagery in the movies may be an important part of the acculturation process associated with smoking initiation.
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Pubertal development in Mexican American girls: the familys perspective.
Qual Health Res
PUBLISHED: 08-20-2009
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Mexican American (MA) girls are entering puberty earlier than in the past, yet few studies have explored the perceptions surrounding puberty among this group. We conducted separate focus groups for fathers, mothers, and daughters aged 6 to 12 years to explore perceptions of body image, pubertal development, communications, and sources of puberty-related information in MA participants. Our results revealed parental concerns about daughters weight and pubertal development, as well as differences in their communication with their daughters. Although both parents willingly discussed pubertal issues concerning their daughters, mothers had a more active role in conveying pubertal information to daughters. Among the girls, there was a gap in knowledge about the pubertal process between the younger and older girls. Our findings present opportunities and challenges for addressing obesity as a pubertal risk factor in MA girls; however, more studies are needed to understand family beliefs and sociocultural dynamics surrounding puberty in MAs.
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LCAT synthesized by primary astrocytes esterifies cholesterol on glia-derived lipoproteins.
J. Lipid Res.
PUBLISHED: 07-08-2009
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Lipid trafficking in the brain is essential for the maintenance and repair of neuronal membranes, especially after neurotoxic insults. However, brain lipid metabolism is not completely understood. In plasma, LCAT catalyses the esterification of free cholesterol on circulating lipoproteins, a key step in the maturation of HDL. Brain lipoproteins are apolipoprotein E (apoE)-containing, HDL-like particles secreted initially as lipid-poor discs by glial cells. LCAT is synthesized within the brain, suggesting that it may play a key role in the maturation of these lipoproteins. Here we demonstrate that astrocytes are the primary producers of brain LCAT. This LCAT esterifies free cholesterol on nascent apoE-containing lipopoproteins secreted from glia. ApoE is the major LCAT activator in glia-conditioned media (GCM), and both the cholesterol transporter ABCA1 and apoE are required to generate glial LCAT substrate particles. LCAT deficiency leads to the appearance of abnormal approximately 8 nm particles in GCM, and exogenous LCAT restores the lipoprotein particle distribution to the wild-type (WT) pattern. In vivo, complete LCAT deficiency results in a dramatic increase in apoE-HDL and reduced apolipoprotein A-I (apoA-I)-HDL in murine cerebrospinal fluid (CSF). These data show that brain LCAT esterifies cholesterol on glial-derived apoE-lipoproteins, and influences CSF apoE and apoA-I levels.
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Maternal current smoking: concordance between adolescent proxy and mothers self-report.
Nicotine Tob. Res.
PUBLISHED: 06-16-2009
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The purpose of this study was to examine the extent to which adolescent reports on mothers smoking status and mothers self-reports on smoking are concordant with one another.
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Visually guided capture of a moving stimulus by the pigeon (Columba livia).
Anim Cogn
PUBLISHED: 05-09-2009
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Although the pigeon is a popular model for studying visual perception, relatively little is known about its perception of motion. Three experiments examined the pigeons ability to capture a moving stimulus. In Experiment 1, the effect of manipulating stimulus speed and the length of the stimulus was examined using a simple rightward linear motion. This revealed a clear effect of length on capture and speed on errors. Errors were mostly anticipatory and there appeared to be two processes contributing to response locations: anticipatory peck bias and lag time. Using the same birds as Experiment 1, Experiment 2 assessed transfer of tracking and capture to novel linear motions. The birds were able to capture other motion directions, but they displayed a strong rightward peck bias, indicating that they had learned to peck to the right of the stimulus in Experiment 1. Experiment 3 used the same task as Experiment 2 but with naïve birds. These birds did not show the rightward bias in pecking and instead pecked more evenly around the stimulus. The combined results indicate that the pigeon can engage in anticipatory tracking and capture of a moving stimulus, and that motion properties and training experience influence capture.
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Visual and response-based navigation in the tortoise (Geochelone carbonaria).
Anim Cogn
PUBLISHED: 05-06-2009
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Much research has investigated spatial cognition in mammals and birds. Evidence suggests that the hippocampus plays a critical role in this; however, reptiles do not possess a hippocampus. It has been proposed that the reptilian medial cortex plays a similar role, yet little behavioral research has directly investigated this. Consequently, this study examined the role of extramaze cues in spatial navigation by the red-footed tortoise (Geochelone carbonaria) using an eight-arm radial maze. In Experiment 1 the maze was surrounded by a black curtain on which geometrical shapes were attached. After the tortoise reached above-chance performance we introduced test sessions in which the cues were removed. Performance was unaffected by cue removal. The tortoise appeared to have developed a "turn-by-one-arm" strategy. In a second experiment the curtain was removed and the tortoise was allowed access to a rich-cue environment. The use of the turn-by-one-arm strategy was significantly reduced and the tortoise appeared to be using the extramaze cues to navigate around the apparatus. This type of response-based strategy, and the specific contexts in which it was used, has not been observed in mammals and birds, suggesting that the mechanisms served by the reptilian medial cortex do not parallel exactly those of the hippocampus.
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Influence of subjective social status on the relationship between positive outcome expectations and experimentation with cigarettes.
J Adolesc Health
PUBLISHED: 03-25-2009
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In Texas, Mexican American (MA) adolescents, and in particular boys, are at increased risk for experimenting with cigarettes compared with their black or white counterparts. Positive outcome expectations (POE), that is, the functional social significance ascribed to cigarettes, and subjective social status (SSS), that is, the adolescents subjective views of where they lie in the school-based social hierarchy, are independent predictors of smoking. The goal of this study was to test the hypothesis that SSS moderates the relationship between POE and experimentation with cigarettes.
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Sociodemographic characteristics, health beliefs, and the accuracy of cancer knowledge.
J Cancer Educ
PUBLISHED: 03-05-2009
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Recent studies have found that knowledge about cancer prevention and treatment differs across ethnic and socioeconomic status (SES) backgrounds, which could directly impact our decisions to engage in protective health behaviors. In this study, we examined sociodemographic-based differences in cancer knowledge and health beliefs and examined differences in the accuracy of the cancer knowledge based on health beliefs.
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Predictors of parent-child relationships that support physical activity in Mexican-American families.
J Behav Med
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Family-based physical activity (PA) interventions would benefit from research that identifies how to build support for PA among family members. This study examined the extent to which relationships of encouragement to do PA, and co-engagement in PA, exist among Mexican-American parents and children, and sought to identify individual, relational, and household factors associated with these dimensions of support. Participants were 224 Mexican-origin adults, with at least one child aged 5-20 years, participating in a larger study conducted between 2008 and 2010. In baseline surveys, adult participants enumerated the names and attributes of their family and kin; this study focuses on 455 parent-child dyads, nested in 118 households. Parental encouragement of PA in their children was found in about half of dyads, and in 20 % of dyads children encouraged parents. Encouragement relationships were highly reciprocal. Reciprocal parent-child encouragement was also positively associated with co-participation in PA; the latter found in just 17 % of dyads. Results indicated that relational, individual, and socio-cultural attributes were associated with PA support among parents and children, and provide insights into how these relationships might be fostered within Mexican-American families.
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Sitting time and health outcomes among Mexican origin adults: obesity as a mediator.
BMC Public Health
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Sitting time and sedentary behaviors have been associated with adverse health outcomes including obesity, diabetes and cardiovascular disease (CVD) within non- Hispanic White populations. Similar associations have not been described within Hispanic populations despite their high CVD risk profile. This study aimed to assess the association between sitting time and obesity, self-reported diagnosed diabetes, hypertension and high cholesterol among a large cohort (N=11,268) of Mexican origin adults and to assess whether obesity mediated these associations.
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Eliminating second-hand smoke from Mexican-American households: outcomes from Project Clean Air-Safe Air (CASA).
Addict Behav
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Exposure to second-hand smoke (SHS) is a major public health problem and a risk factor for morbidity and mortality. The objective of this randomized trial was to estimate the impact of a culturally-sensitive intervention to reduce SHS exposure in Mexican-American households.
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Picture-object recognition in the tortoise Chelonoidis carbonaria.
Anim Cogn
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To recognize that a picture is a representation of a real-life object is a cognitively demanding task. It requires an organism to mentally represent the concrete object (the picture) and abstract its relation to the item that it represents. This form of representational insight has been shown in a small number of mammal and bird species. However, it has not previously been studied in reptiles. This study examined picture-object recognition in the red-footed tortoise (Chelonoidis carbonaria). In Experiment 1, five red-footed tortoises were trained to distinguish between food and non-food objects using a two-alternative forced choice procedure. After reaching criterion, they were presented with test trials in which the real objects were replaced with color photographs of those objects. There was no difference in performance between training and test trials, suggesting that the tortoises did see some correspondence between the real object and its photographic representation. Experiment 2 examined the nature of this correspondence by presenting the tortoises with a choice between the real food object and a photograph of it. The findings revealed that the tortoises confused the photograph with the real-life object. This suggests that they process real items and photographic representations of these items in the same way and, in this context, do not exhibit representational insight.
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Experimenting with cigarettes and physical activity among Mexican origin youth: a cross sectional analysis of the interdependent associations among sensation seeking, acculturation, and gender.
BMC Public Health
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Sensation seeking tendencies tend to manifest during adolescence and are associated with both health-compromising behaviors and health-enhancing behaviors. The purpose of this study is to evaluate the relationship between sensation seeking and physical activity, a health-enhancing behavior, and between sensation seeking and experimenting with cigarettes, a health compromising-behavior, among a cohort of Mexican origin adolescents residing in the United States with different levels of acculturation.
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You sound familiar: carrion crows can differentiate between the calls of known and unknown heterospecifics.
Anim Cogn
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In group-living animals, it is adaptive to recognize conspecifics on the basis of familiarity or group membership as it allows association with preferred social partners and avoidance of competitors. However, animals do not only associate with conspecifics but also with heterospecifics, for example in mixed-species flocks. Consequently, between-species recognition, based either on familiarity or even individual recognition, is likely to be beneficial. The extent to which animals can distinguish between familiar and unfamiliar heterospecifics is currently unclear. In the present study, we investigated the ability of eight carrion crows to differentiate between the voices and calls of familiar and unfamiliar humans and jackdaws. The crows responded significantly more often to unfamiliar than familiar human playbacks and, conversely, responded more to familiar than unfamiliar jackdaw calls. Our results provide the first evidence that birds can discriminate between familiar and unfamiliar heterospecific individuals using auditory stimuli.
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Radial-arm-maze behavior of the red-footed tortoise (Geochelone carbonaria).
J Comp Psychol
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The radial-arm maze is an established method for testing an animals spatial win-shift behavior. Research on mammals, birds, and fish has shown that the mastery of this task is commonly mediated, to different degrees, by two types of strategy: those based on external cues and those based on response stereotypy. In the present study we trained four red-footed tortoises (Geochelone carbonaria) to navigate an eight-arm radial maze while providing different levels of access to visual room cues. The results indicate that response stereotypy is the more prevalent mechanism in these tortoises, although navigation based on landmarks can also occur if learned initially. The findings suggest that tortoise spatial navigation may be more similar to that observed in mammals and birds than previously thought.
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Incidence and risk factors associated with chlamydia in men who have sex with men: a cohort analysis of Victorian Primary Care Network for Sentinel Surveillance data.
Sex Transm Infect
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Chlamydia is the most commonly notified sexually transmitted infection (STI) in Australia. Incidence studies of chlamydia in men who have sex with men (MSM) are rare and offer important public health information.
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Exposure to Pro-tobacco Messages and Smoking Status Among Mexican Origin Youth.
J Immigr Minor Health
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Though several studies have found a positive relationship between exposure to tobacco advertising and/or promotional marketing and smoking status among youth, few have examined these relationships specifically for youth of Mexican origin. The current analysis examines the relationship between perceived exposure to pro-tobacco messages and progression through the smoking continuum from trying to repeated use in a cohort of Mexican origin youth ages 14-19. Data were collected via personal in-home interviews at two time points-in 2008-2009 and 2010-2011 (N = 942). Smoking status, exposure to pro-tobacco messages from five major media sources, demographic variables and established risk factors for adolescent smoking were measured at both waves. Data were analyzed using Pearsons Chi square tests, ANOVA, and multinomial logistic regression. Adolescent perception of the number of pro-tobacco messages seen in 2008-2009 was unrelated to smoking less than one cigarette assessed in 2010-2011. However, having seen a higher number of pro-tobacco messages was significantly associated with being more likely to have smoked more than one cigarette (OR = 1.21; 95 % CI 1.03-1.42) controlling for demographic factors and known psychosocial risk factors of smoking behavior. Results suggest that the more pro-tobacco messages Mexican origin youth are able to recall, the further their progression through the smoking trajectory a year later. These youth are clearly susceptible to pro-tobacco messaging, and our results underscore the need to restrict all forms of messaging that promote tobacco use.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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We use abstracts found on PubMed and match them to JoVE videos to create a list of 10 to 30 related methods videos.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.