Evolutionary and Physical Properties of Meteoroids

Astrophysical models for meteoroid formation and stellar and planetary evolutions are developed from simulation composition studies

Image-orthicon spectra of Geminids in 1969

The spectra of 25 meteors, recorded with an image orthicon technique in December 1969, are studied in relation to similar records made in August of the same year. Of 19 Geminid meteors in the absolute visual magnitude range 0 to +2, only one showed any evidence of the forbidden line of oxygen at 5577 A, while all Perseid meteors recorded in August exhibited the oxygen line, a result of the large difference in geocentric velocity between the two showers. Atoms identified in faint Geminid meteors include neutral iron, magnesium, calcium and sodium. The molecular bands of nitrogen are also observed

An unusual meteor spectrum

An extraordinary spectrum of a meteor at a velocity of about 18.5 + or - 1.0 km/s was observed with an image orthicon camera. The radiant of the meteor was at an altitude of about 49 deg. It was first seen showing a yellow red continuous spectrum alone at a height of 137 + or - 8 km which is ascribed to the first positive group of nitrogen bands. After the meteor had descended to 116 + or - 6 km above sea level it brightened rapidly from its previous threshold brightness into a uniform continuum, the D-line of neutral sodium appeared, and at height 105 + or - 5 km all the other lines of the spectrum also appeared. The continuum remained dominant to the end. Water of hydration and entrained carbon flakes of characteristic dimension about 0.2 micron or less are proposed as constituents of the meteoroid to explain these phenomena

Assessment of Detection of Potential Dog-Bite Risks in the Home Using a Real-Time Hazard Perception Test

Dog bites are a serious public health concern internationally and children are often at particular risk of them. Because bites to children often occur during apparently benign interactions with a parent present, the need for dog-bite prevention approaches to address adults’ awareness of, and supervision of, child–dog interactions has been highlighted. The aim of this study was to evaluate a hazard perception test of potential dog-bite hazards within a home setting. Six hazards were incorporated in a 2-minute 41-second video, which was embedded into a web-based interface that enabled respondents to identify hazards by clicking the mouse button or tapping the screen of a tablet computer as the video played. The 268 volunteer respondents also completed a short questionnaire. These respondents were predominantly female and appeared more likely to have undertaken higher education and have greater experience with dogs than the general population. Almost one-third (31.8%) of respondents identified all six hazards, and a further quarter (24.5%) missed only one; a quarter (25.2%) identified 3 or fewer; and 43.8% identified 4 or fewer hazards. No one scored zero, and 5.5% and 6.9% identified 1 and 2 hazards, respectively. A range of factors was associated with the identification of specific hazards. Participants with professional or long-term experience with dogs and those with higher educational attainment were more likely to detect some hazards. Older respondents were less likely to identify several of the hazards, and those living with children were less likely to identify cuddling a dog as a hazard. We find that hazard perception testing could be a useful tool for the assessment of knowledge regarding dog-bite risk situations and potentially an educational tool for increasing knowledge and changing practices around dogs

Effects of flow rate and gas mixture on the welfare of weaned and neonate pigs during gas euthanasia

The objectives of this study were to assess efficacy and welfare implications of gas euthanasia when applied to weaned and neonate pigs. Parameters associated with welfare, which were measured before loss of consciousness, included open-mouth breathing, ataxia, righting response, and escape attempts. Two age groups (weaned and neonate) were assessed in 9 gas treatments arranged in a 2 × 4 factorial design, with 2 gas types (CO2 = 100% CO2 and 50:50 = 50:50 CO2:argon) and 4 flow rates (box volume exchange/min: slow = 20%; medium = 35%; fast = 50%; prefill = prefilled followed by 20%) and a control treatment in which ambient air was passed through the box. Pig pairs (10/treatment) were placed in a modified Euthanex AgPro system (Euthanex Corp., Palmer, PA). Behavioral and physiological responses were observed directly and from video recordings for latency, duration, prevalence (percent of pigs affected), and frequency (number of occurrences/pig). Data were analyzed as linear mixed models or with a Cox proportional hazard model as appropriate. Piglet pair was the experimental unit. For the weaned pig, welfare was superior with CO2 relative to 50:50 within 1 or more flow rates on the basis of reduced duration of open-mouth breathing, duration of ataxia, frequency of escape attempts, and duration and frequency of righting response (P \u3c 0.05). No measured parameters indicated superior welfare with the use of 50:50, whereas latencies to loss of posture and last movement favored CO2 (P \u3c 0.05). Faster flow rates were associated with reduced (P \u3c 0.05) duration or frequency of open-mouth breathing, ataxia, and righting response, as well as superior (P\u3c 0.05) indicators of efficacy, including latencies to loss of posture, gasping, and last movement, relative to slower flow rates. Weaned pigs were more likely to defecate (P \u3c 0.01), display nasal discharge (P \u3c 0.05), and display longer (P \u3c 0.001) latencies to loss of posture and last movement than neonates. Duration of ataxia was the only parameter for which neonates were superior (P \u3c 0.01) to weaned pigs during euthanasia. As such, a 50:50 CO2:argon gas mixture and slower flow rates should be avoided when euthanizing weaned or neonate pigs with gas methods. Neonate pigs succumb to the effects of gas euthanasia quicker than weaned pigs and display fewer signs of distress

Prevalence of antibiotic-resistant E. coli in retail chicken: Comparing conventional, organic, kosher, and raised without antibiotics

Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) – designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April – June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen

Prevalence of antibiotic-resistant E. coli in retail chicken: Comparing conventional, organic, kosher, and raised without antibiotics

Retail poultry products are known sources of antibiotic-resistant Escherichia coli, a major human health concern. Consumers have a range of choices for poultry, including conventional, organic, kosher, and raised without antibiotics (RWA) – designations that are perceived to indicate differences in quality and safety. However, whether these categories vary in the frequency of contamination with antibiotic-resistant E. coli is unknown. We examined the occurrence of antibiotic-resistant E. coli on raw chicken marketed as conventional, organic, kosher and RWA. From April – June 2012, we purchased 213 samples of raw chicken from 15 locations in the New York City metropolitan area. We screened E. coli isolates from each sample for resistance to 12 common antibiotics. Although the organic and RWA labels restrict the use of antibiotics, the frequency of antibiotic-resistant E. coli tended to be only slightly lower for RWA, and organic chicken was statistically indistinguishable from conventional products that have no restrictions. Kosher chicken had the highest frequency of antibiotic-resistant E. coli, nearly twice that of conventional products, a result that belies the historical roots of kosher as a means to ensure food safety. These results indicate that production methods influence the frequency of antibiotic-resistant E. coli on poultry products available to consumers. Future research to identify the specific practices that cause the high frequency of antibiotic-resistant E. coli in kosher chicken could promote efforts to reduce consumer exposure to this potential pathogen

Glutathione and growth inhibition of Mycobacterium tuberculosis in healthy and HIV infected subjects

Intracellular levels of glutathione are depleted in patients with acquired immunodeficiency syndrome in whom the risk of tuberculosis, particularly disseminated disease is many times that of healthy individuals. In this study, we examined the role of glutathione in immunity against tuberculosis infection in samples derived from healthy and human immunodeficiency virus infected subjects. Our studies confirm that glutathione levels are reduced in peripheral blood mononuclear cells and in red blood cells isolated from human immunodeficiency virus-infected subjects (CD4>400/cumm). Furthermore, treatment of blood cultures from human immunodeficiency virus infected subjects with N-acetyl cysteine, a glutathione precursor, caused improved control of intracellular M. tuberculosis infection. N-acetyl cysteine treatment decreased the levels of IL-1, TNF-α, and IL-6, and increased the levels of IFN-γ in blood cultures derived from human immunodeficiency virus-infected subjects, promoting the host immune responses to contain M. tuberculosis infection successfully

The Prevalence of Depersonalization-Derealization Disorder: A Systematic Review

35 pagesDepersonalization-Derealization disorder (DDD) is a psychiatric condition characterized by persistent feelings of detachment from one’s self and of unreality about the outside world. This review aims to examine the prevalence of DDD amongst different populations. A systematic review protocol was developed before literature searching. Original articles were drawn from three electronic databases and included only studies where prevalence rates of DDD were assessed by standardized diagnostic tools. A narrative synthesis was conducted. Twenty-three papers were identified and categorized into three groups of participants: general population, mixed in/outpatient samples, and patients with specific disorders. The prevalence rates ranged from 0% to 1.9% amongst the general population, 5–20% in outpatients and 17.5–41.9% in inpatients. In studies of patients with specific disorders, prevalence rates varied: 1.8–5.9% (substance abuse), 3.3–20.2% (anxiety), 3.7–20.4% (other dissociative disorders), 16.3% (schizophrenia), 17% (borderline personality disorder), ~50% (depression). The highest rates were found in people who experienced interpersonal abuse (25–53.8%). The prevalence rate of DDD is around 1% in the general population, consistent with previous findings. DDD is more prevalent amongst adolescents and young adults as well as in patients with mental disorders. There is also a possible relationship between interpersonal abuse and DDD, which merits further research