1,410 research outputs found
A study of the effects of micro-gravity on seed germination
This study will identify characteristics of seed germination dependent upon gravity. To accomplish this objective, four different seed types will be germinated in space and then be compared to a control group germinated on Earth. Both the experimental and control groups will be analyzed on the cellular level for the size of cells, structural anomalies, and gravitational effects. The experiment will be conducted in a Get Away Special Canister (GAS Can no. 608) owned by the U.S. Space and Rocket Center and designed for students. The GAS Can will remain in the cargo bay of the Space Shuttle with minimal astronaut interaction
A Comparative Analysis of Post-Traumatic Stress Syndrome among Individuals Exposed to Different Stressor Events
The purpose of the present study was to compare post-traumatic stress syndrome among persons involved in nine different stressor events: combat in the Vietnam War; rape; serious life-threatening events; divorce; the death of a significant other; critical, near fatal illness of a significant other; family trauma; multiple traumatic events; and no stressful event. To assess the severity of the symptoms which define post-traumatic stress disorder (PTSD), the Impact of Event Scale, the Beck Depression Inventory, the Stress Assessment Scale for PTSD from the Vietnam Era Stress Inventory (Wilson & Krauss, 1980) and the Sensation Seeking Scale were administered to the participants (N=409). A person by situation conceptual model of PTSD was presented from which two major hypotheses were tested. As predicted from the model, the degree of loss of a significant other and life-threat were predictive of syndromespecific symptoms of PTSD. The results of the study strongly support the heuristic value of an interactionist model of PTSD
Proline residues within spacer peptide p1 are important for human immunodeficiency virus type 1 infectivity, protein processing, and genomic RNA dimer stability
The full-length human immunodeficiency virus type 1 (HIV-1) mRNA encodes two precursor polyproteins, Gag and GagProPol. An infrequent ribosomal frameshifting event allows these proteins to be synthesized from the same mRNA in a predetermined ratio of 20 Gag proteins for each GagProPol. The RNA frameshift signal consists of a slippery sequence and a hairpin stem-loop whose thermodynamic stability has been shown in in vitro translation systems to be critical to frameshifting efficiency. In this study we examined the frameshift region of HIV-1, investigating the effects of altering stem-loop stability in the context of the complete viral genome and assessing the role of the Gag spacer peptide p1 and the GagProPol transframe (TF) protein that are encoded in this region. By creating a series of frameshift region mutants that systematically altered the stability of the frameshift stem-loop and the protein sequences of the p1 spacer peptide and TF protein, we have demonstrated the importance of stem-loop thermodynamic stability in frameshifting efficiency and viral infectivity. Multiple changes to the amino acid sequence of p1 resulted in altered protein processing, reduced genomic RNA dimer stability, and abolished viral infectivity. The role of the two highly conserved proline residues in p1 (position 7 and 13) was also investigated. Replacement of the two proline residues by leucines resulted in mutants with altered protein processing and reduced genomic RNA dimer stability that were also noninfectious. The unique ability of proline to confer conformational constraints on a peptide suggests that the correct folding of p1 may be important for viral function.<br /
Serological Cross-Reactivity of the Novel H1N1 and Implications for Protection with a Commerical Vaccine
The recent emergence of the pandemic H1N1 viruses and their being labeled as ‘swine flu’ has had several detrimental effects on the pork industry. Novel H1N1 strains have been recently detected in swine populations in the United States and in other parts of the world. While the public health significance of these findings is unknown, it is important to determine whether existing vaccines or exposure to previously circulating strains of swine influenza will protect pigs against the novel H1N1. Using a partial two-way cross-hemagglutination inhibition (HI) assay, we have determined a swine H1N1 strain present in a commercial vaccine cross-reacted with antiserum specific to the novel H1N1. We have also shown that a field serum sample with a HI high titer to a ’99 H1N1 strain crossreacted strongly with the novel H1N1. Anti-sera which were specific to the non-pandemic H1N1 strains also crossreacted with the novel H1N1. Therefore, we conclude that current vaccines and circulating non-pandemic H1N1 field strains will provide at least partial protection against the novel H1N1 virus in pigs
Rhythms of locomotion and seasonal changes in activity expressed by horseshoe crabs in their natural habitat
The American horseshoe crab Limulus polyphemus expresses both tidal and daily rhythms of locomotion in the laboratory and the tidal rhythms can be entrained to artificial tides. The main purpose of this study was to determine the types of rhythms horseshoe crabs express when freely moving in their natural habitat where they are exposed to natural light:dark and tidal cycles. A secondary goal was to determine if their overall activity patterns and depth preferences changed during the year. In 2010 and 2011, 20 adult horseshoe crabs (11 males, 9 females) were fitted with ultrasonic tags and released in the Great Bay Estuary, NH, USA. The tags transmitted acceleration and depth data every 3 to 5 min from June until December during the year in which they were tagged, and from March to May of the following year. Acoustic transmissions from the tags were detected and logged by a series of VR2W receivers moored throughout the estuary. Accelerometer data were used to assess when animals were active and to determine (1) whether they were expressing tidal or daily rhythms and (2) their overall activity level each month. We discovered that horseshoe crabs were just as likely to express tidal rhythms as daily rhythms, despite being continuously exposed to natural tide cycles. In addition, there was a tendency to move into deeper water and become less active as water temperatures cooled in the fall, and then to move up into the estuary and become more active as water temperatures warmed in the spring
Insights about Cannabis and Psychosis Using Video Games for Young People with a First Episode of Psychosis, Particularly Those from Black Racialized Communities: Protocol for a Mixed Methods Study
Background: Cannabis use disorder among young people with a first episode of psychosis contributes to relapse, hospitalization, and impaired functioning. However, few studies have examined what young people with early phase psychosis, particularly those from Black racialized communities, understand or appreciate about this relationship, even though they may be at risk. There are no formally tested knowledge translation strategies that disseminate these research findings for young people with emerging psychosis from Black racialized communities. Objective: This study aims to conceptualize what young people with early phase psychosis/cannabis use disorder understand about the relationship between cannabis and psychosis, focusing on people from racialized backgrounds. This study also aims to assess whether the knowledge translation product, the “Back to Reality Series,” increases awareness of the impact of cannabis use on psychosis from the perspectives of young people with emerging psychosis and cannabis use disorder from Black African and Caribbean communities. Methods: Qualitative analysis will reveal themes from qualitative interviews about cannabis and psychosis from the perspectives of young people with emerging psychosis and cannabis use disorder from Black African and Caribbean communities. Perceptions before and after exposure to the Back to Reality Series will be qualitatively analyzed. A control game will be used for comparison, and scores on a quiz after playing the Back to Reality Series will be quantitatively analyzed to establish whether the Back to Reality Series raises awareness of the effects of cannabis on psychosis. An advisory council involving young people from Black communities, family members, and clinicians will bring community perspectives to this research. Results: We began recruiting participants for this study in September 2021. We will complete data collection on demographic and clinical factors, qualitative interviews, and quantitative assessments of the Back to Reality Series. Conclusions: The voices of young people from racialized backgrounds will generate preliminary data to inform early psychosis programs, addressing cannabis use in this population. The findings may advance the use of a new knowledge translation product that deals with gaps in knowledge about cannabis use for people experiencing early phase psychosis, particularly those from racialized communities
Review: Assessment of completeness of reporting in intervention studies using livestock: an example from pain mitigation interventions in neonatal piglets
Accurate and complete reporting of study methods, results and interpretation are essential components for any scientific process, allowing end-users to evaluate the internal and external validity of a study. When animals are used in research, excellence in reporting is expected as a matter of continued ethical acceptability of animal use in the sciences. Our primary objective was to assess completeness of reporting for a series of studies relevant to mitigation of pain in neonatal piglets undergoing routine management procedures. Our second objective was to illustrate how authors can report the items in the Reporting guidElines For randomized controLled trials for livEstoCk and food safety (REFLECT) statement using examples from the animal welfare science literature. A total of 52 studies from 40 articles were evaluated using a modified REFLECT statement. No single study reported all REFLECT checklist items. Seven studies reported specific objectives with testable hypotheses. Six studies identified primary or secondary outcomes. Randomization and blinding were considered to be partially reported in 21 and 18 studies, respectively. No studies reported the rationale for sample sizes. Several studies failed to report key design features such as units for measurement, means, standard deviations, standard errors for continuous outcomes or comparative characteristics for categorical outcomes expressed as either rates or proportions. In the discipline of animal welfare science, authors, reviewers and editors are encouraged to use available reporting guidelines to ensure that scientific methods and results are adequately described and free of misrepresentations and inaccuracies. Complete and accurate reporting increases the ability to apply the results of studies to the decision-making process and prevent wastage of financial and animal resources
Effect of aerobic exercise on amyloid accumulation in preclinical Alzheimer’s: A 1-year randomized controlled trial
Background
Our goal was to investigate the role of physical exercise to protect brain health as we age, including the potential to mitigate Alzheimer’s-related pathology. We assessed the effect of 52 weeks of a supervised aerobic exercise program on amyloid accumulation, cognitive performance, and brain volume in cognitively normal older adults with elevated and sub-threshold levels of cerebral amyloid as measured by amyloid PET imaging.
Methods and findings
This 52-week randomized controlled trial compared the effects of 150 minutes per week of aerobic exercise vs. education control intervention. A total of 117 underactive older adults (mean age 72.9 [7.7]) without evidence of cognitive impairment, with elevated (n = 79) or subthreshold (n = 38) levels of cerebral amyloid were randomized, and 110 participants completed the study. Exercise was conducted with supervision and monitoring by trained exercise specialists. We conducted 18F-AV45 PET imaging of cerebral amyloid and anatomical MRI for whole brain and hippocampal volume at baseline and Week 52 follow-up to index brain health. Neuropsychological tests were conducted at baseline, Week 26, and Week 52 to assess executive function, verbal memory, and visuospatial cognitive domains. Cardiorespiratory fitness testing was performed at baseline and Week 52 to assess response to exercise. The aerobic exercise group significantly improved cardiorespiratory fitness (11% vs. 1% in the control group) but there were no differences in change measures of amyloid, brain volume, or cognitive performance compared to control.
Conclusions
Aerobic exercise was not associated with reduced amyloid accumulation in cognitively normal older adults with cerebral amyloid. In spite of strong systemic cardiorespiratory effects of the intervention, the observed lack of cognitive or brain structure benefits suggests brain benefits of exercise reported in other studies are likely to be related to non-amyloid effects
Case study: Treatment of oral and locomotory stereotypic behaviors in a mature sow
A 32-month-old female 225-kg nonpregnant cross-bred Newsham sow presented a 6-week history of stereotypic behaviors when housed in a laboratory research facility. A behavioral examination over 12 daylight hours revealed 3 main stereotypic motor patterns, namely (1) oral-nasal gate manipulation defined as placement of the snout between the bars of the pen gate with repetitive, forceful up and down movement; (2) head weaving defined as repetitive lateral head and snout movement toward the pen gates while rocking back and forth on her forequarters with hooves remaining on ground at all times; and (3) body weaving defined as repetitive shifting of body weight from one side to the other with front hooves lifting alternately off the ground. The sow performed the oral-nasal gate manipulation and head and body weaving 4.0%, 12.4%, and 6.8% of her total baseline time budget, respectively. The presumptive diagnosis was oral-nasal and locomotory stereotypies. Three treatments were used to mitigate the duration and frequency of these stereotypic behaviors. Treatment 1—Social treatment (change social stimuli by providing visual and nose-to-nose contact with different neighboring sows); Treatment 2—Forage treatment (change foraging substrates by providing peat moss as a rooting substrate); and Treatment 3—Space treatment (change pen configuration by increasing space). The sow performed the oral-nasal gate manipulation and head and body weaving 0%, 0.4%, and 0.1% of her total time budget, respectively; social treatment: the sow performed the oral-nasal gate manipulation and head and body weaving 0.9%, 15.3%, and 11.3% of her total time budget, respectively; and forage treatment: the sow performed the oral-nasal gate manipulation and head and body weaving 0.5%, 28.0%, and 15.5% of her total time budget, respectively. This study is one of the first reports to evaluate the treatment of established stereotypies in a mature sow. Results suggest the promise of environmental enrichment as an effective treatment strategy. Further research is needed to evaluate the persistence of these behavioral changes and relative importance of different environmental manipulations provided
Population-level impact and herd effects following the introduction of human papillomavirus vaccination programmes: updated systematic review and meta-analysis
Background More than 10 years have elapsed since human papillomavirus (HPV) vaccination was implemented. We did a systematic review and meta-analysis of the population-level impact of vaccinating girls and women against human papillomavirus on HPV infections, anogenital wart diagnoses, and cervical intraepithelial neoplasia grade 2+ (CIN2+)to summarise the most recent evidence about the effectiveness of HPV vaccines in real-world settings and to quantify the impact of multiple age-cohort vaccination.Methods In this updated systematic review and meta-analysis, we used the same search strategy as in our previous paper. We searched MEDLINE and Embase for studies published between Feb 1, 2014, and Oct 11, 2018. Studies were eligible if they compared the frequency (prevalence or incidence) of at least one HPV-related endpoint (genital HPV infections, anogenital wart diagnoses, or histologically confirmed CIN2+) between pre-vaccination and post-vaccination periods among the general population and if they used the same population sources and recruitment methods before and after vaccination. Our primary assessment was the relative risk (RR) comparing the frequency (prevalence or incidence) of HPV-related endpoints between the pre-vaccination and post-vaccination periods. We stratified all analyses by sex, age, and years since introduction of HPV vaccination. We used random-effects models to estimate pooled relative risks.Findings We identified 1702 potentially eligible articles for this systematic review and meta-analysis, and included 65 articles in 14 high-income countries: 23 for HPV infection, 29 for anogenital warts, and 13 for CIN2+.After 5\u20138 years of vaccination, the prevalence of HPV 16 and 18 decreased significantly by 83% (RR 0\ub717, 95% CI 0\ub711\u20130\ub725) among girls aged 13\u201319 years, and decreased significantly by 66% (RR 0\ub734, 95% CI 0\ub723\u20130\ub749) among women aged 20\u201324 years. The prevalence of HPV 31, 33, and 45 decreased significantly by 54% (RR 0\ub746, 95% CI 0\ub733\u20130\ub766) among girls aged 13\u201319 years. Anogenital wart diagnoses decreased significantly by 67% (RR 0\ub733, 95% CI 0\ub724\u20130\ub746) among girls aged 15\u201319 years, decreased significantly by 54% (RR 0\ub746, 95% CI 0.36\u20130.60) among women aged 20\u201324 years, and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub753\u20130\ub789) among women aged 25\u201329 years. Among boys aged 15\u201319 years anogenital wart diagnoses decreased significantly by 48% (RR 0\ub752, 95% CI 0\ub737\u20130\ub775) and among men aged 20\u201324 years they decreased significantly by 32% (RR 0\ub768, 95% CI 0\ub747\u20130\ub798). After 5\u20139 years of vaccination, CIN2+ decreased significantly by 51% (RR 0\ub749, 95% CI 0\ub742\u20130\ub758) among screened girls aged 15\u201319 years and decreased significantly by 31% (RR 0\ub769, 95% CI 0\ub757\u20130\ub784) among women aged 20\u201324 years.Interpretation This updated systematic review and meta-analysis includes data from 60 million individuals and up to 8 years of post-vaccination follow-up. Our results show compelling evidence of the substantial impact of HPV vaccination programmes on HPV infections and CIN2+ among girls and women, and on anogenital warts diagnoses among girls, women, boys, and men. Additionally, programmes with multi-cohort vaccination and high vaccination coverage had a greater direct impact and herd effects
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