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Newton's Principia is perhaps the second most famous work of mathematics, after Euclid's Elements. Originally published in 1687, it gave the first systematic account of the fundamental concepts of dynamics, as well as three beautiful derivations of Newton's law of gravitation from Kepler's laws of planetary motion. As a book of great insight and ingenuity, it has raised our understanding of the power of mathematics more than any other work. This heavily annotated translation of the third and final edition (1726) of the Principia will enable any reader with a good understanding of elementary mathematics to easily grasp the meaning of the text, either from the translation itself or from the notes, and to appreciate some of its significance. All forward references are given to illuminate the structure and unity of the whole, and to clarify the parts. The mathematical prerequisites for understanding Newton's arguments are given in a brief appendix.
Dementia, a term that describes a variety of brain conditions marked by gradual, persistent and progressive cognitive decline, affects a significant proportion of older adults. Older adults with dementia are sometimes perceived less favourably than those without dementia. Furthermore, compared to persons without dementia, those with dementia are often perceived by others as having reduced personhood. This study was aimed at investigating whether differences in attitudes towards dementia and personhood perceptions vary as a function of age group, care-giver status, attitudes towards ageing, dementia knowledge, gender and education. In total 196 younger, middle-aged and older adults were recruited. Findings revealed that being a care-giver as well as having less ageist attitudes were predictive of being more comfortable around persons with dementia, having more knowledge about dementia and ascribing greater personhood to people with dementia. Those with more dementia knowledge (prior to the study) were less comfortable around people with dementia. Finally, when controlling this prior dementia knowledge, older adults were more comfortable around people with dementia compared to younger and middle-aged adults. Gender and education were not associated with any of the variables under study. Findings contribute to a better understanding of the role of age- and care-giver-related factors in the determination of attitudes towards dementia.
Solid specimens of silver were charged at different temperatures in atmospheres of oxygen and of hydrogen. X-ray diffraction line profiles were obtained using powders filed from the treated specimens. Fourier analysis of the diffraction lines was conducted following the method of Warren. The effective particle sizes and root-mean-square strains were obtained from the line shape analysis. Stacking fault and twin fault probabilities were determined from peak-position and center-of gravity displacements, respectively. For the purpose of comparison, two vacuum-melted silver samples and two different silver-tin alloys were studied. The stacking fault and twin fault probabilities were observed to be nearly unaffected by charging in either oxygen or hydrogen. These results are consistent with recent direct determinations of the effect of oxygen on the stacking fault energy of silver. In contrast, the rms strains and particle sizes changed significantly after charging in oxygen. A decrease in the root-mean-square strain and a corresponding increase in the particle size was found. These effects were opposite to those obtained by adding substitutional solute to silver. These findings are interpreted to indicate the effect of oxygen clustered with impurities on the dislocations and stacking faults in silver.
Cultivar mixtures of winter barley and spring barley, together with their component monocultures, were grown in field trials to assess the effect of cultivar combinations on both straw and grain yield. The overall grain yields for all trials were significantly higher for the cultivar mixtures than for the corresponding component monocultures. Also, significant decreases in rhynchosporium disease severity for cultivar mixtures were recorded for most non-fungicide treatments. The size of these responses was often significantly correlated with the component number of the mixtures. The amount of straw produced in mixtures was sometimes changed significantly, but not always in a positive direction and it was only correlated with increasing mixture component number in two environments. No correlation of straw yield potential of cultivars with performance in mixtures was found. Cultivar × cultivar mixture × environment interactions appeared to affect the relative yield of grain and straw differentially and therefore it was not possible to predict the effect of mixtures on the harvest index.
Problematic alcohol use is associated with detrimental cognitive, physiological and social consequences. In the emergency department (ED), Screening, Brief Intervention, and Referral to Treatment (SBIRT) is the recommended approach to identify and treat adolescent alcohol-related concerns, but is underused by physicians.
This study examined pediatric emergency physicians’ perceptions of adolescent drinking and treatment, and their current self-reported SBIRT practices.
Physicians in the Pediatric Emergency Research Canada database (n=245) received a 35-item questionnaire that was administered through a web-based platform and paper-based mail-outs. Recruitment followed a modified Dillman four-contact approach.
From October 2016 to January 2017, 166 pediatric emergency physicians (46.4% males; mean age=43.6 years) completed the questionnaire. The response rate was 67.8%. Physicians recognized the need (65%) and responsibility (86%) to address adolescent alcohol problems. However, confidence in knowledge and abilities for SBIRT execution was low. Twenty-five percent of physicians reported never having practiced all, or part of, SBIRT while 1.3% reported consistent SBIRT delivery for adolescents with alcohol-related visits. More alcohol education and counselling experience was associated with higher SBIRT use; however, physicians generally reported to have received minimal alcohol training. SBIRT practices were also associated with physician perceptions of problematic alcohol use and its treatability.
Pediatric emergency physicians acknowledge the need to address problematic adolescent alcohol use, but routine SBIRT use is lacking. Strategies to educate physicians about SBIRT and enhance perceived self-competency may improve SBIRT use. Effectiveness trials to establish SBIRT impact on patient outcomes are also needed.
Epstein Barr virus (EBV) infects 95% of the global population and is associated with up to 2% of cancers globally. Immunoglobulin G (IgG) antibody levels to EBV have been shown to be heritable and associated with developing malignancies. We, therefore, performed a pilot genome-wide association analysis of anti-EBV IgG traits in an African population, using a combined approach including array genotyping, whole-genome sequencing and imputation to a panel with African sequence data. In 1562 Ugandans, we identify a variant in human leukocyte antigen (HLA)-DQA1, rs9272371 (p = 2.6 × 10−17) associated with anti-EBV nuclear antigen-1 responses. Trans-ancestry meta-analysis and fine-mapping with European-ancestry individuals suggest the presence of distinct HLA class II variants driving associations in Uganda. In addition, we identify four putative, novel, very rare African-specific loci with preliminary evidence for association with anti-viral capsid antigen IgG responses which will require replication for validation. These findings reinforce the need for the expansion of such studies in African populations with relevant datasets to capture genetic diversity.
Introduction: Active substance use and unstable housing are both associated with increased emergency department (ED) utilization. This study examined ED health care costs among a cohort of substance using and/or homeless adults following an index ED visit, relative to a control ED population. Methods: Consecutive patients presenting to an inner-city ED between August 2010 and November 2011 who reported unstable housing and/or who had a chief presenting complaint related to acute or chronic substance use were evaluated. Controls were enrolled in a 1:4 ratio. Participants’ health care utilization was tracked via electronic medical record for six months after the index ED visit. Costing data across all EDs in the region was obtained from Alberta Health Services and calculated to include physician billing and the cost of an ED visit excluding investigations. The cost impact of ED utilization was estimated by multiplying the derived ED cost per visit by the median number of visits with interquartile ranges (IQR) for each group during follow up. Proportions were compared using non-parametric tests. Results: From 4679 patients screened, 209 patients were enrolled (41 controls, 46 substance using, 91 unstably housed, 31 both unstably housed and substance using (UHS)). Median costs (IQR) per group over the six-month period were $0 ($0-$345.42) for control, $345.42 ($0-$1139.89) for substance using, $345.42 ($0-$1381.68) for unstably housed and $1381.68 ($690.84-$4248.67) for unstably housed and substance using patients (p<0.05). Conclusion: The intensity of excess ED costs was greatest in patients who were both unstably housed and presenting with a chief complaint related to substance use. This group had a significantly larger impact on health care expenditure relative to ED users who were not unstably housed or who presented with a substance use related complaint. Further research into how care or connection to community resources in the ED can reduce these costs is warranted.
A range of wheat cultivars, including elite cultivars, older cultivars and some preferred by organic growers, were trialled under high and low nitrogen (N) conventional and organic conditions to determine whether cultivars that yield highly under organic conditions have the same relative yield under conventional conditions. A range of cultivar mixtures was also assessed to see whether these gave yield advantages or superiority in either farming system. The conventional trials were grown with and without full fungicide programmes, which largely controlled disease. Amongst the cultivars, Alchemy showed superior yield under organic conditions as did Pegassos, but under conventional conditions Pegassos was always one of the low-ranking cultivars. Under conventional conditions the more recent cultivars Alchemy, Glasgow and Istabraq yielded highly, while an older one, Consort, yielded highly under low fertilizer conditions, and both Ambrosia and Deben also yielded highly generally. Fungicide and high N favoured the disease-susceptible, high-yield cultivars such as Glasgow whereas Consort, an older susceptible cultivar, was favoured by fungicide and low N. Together this demonstrates that whilst the yield characteristics of some elite germplasm are also expressed under organic conditions, at least one cultivar that yielded poorly under conventional conditions showed adaptation towards the organic conditions of these trials. Other cultivars yielding poorly under conventional conditions also gave poor yield under organic conditions. The equal proportion mixtures of cultivars grown under conventional conditions showed no evidence of differences in yield from the mean of the component cultivars grown separately, but combinations of Glasgow, Alchemy and Istabraq gave consistently high yield.
No existing models of alcohol prevention concurrently adopt universal and selective approaches. This study aims to evaluate the first combined universal and selective approach to alcohol prevention.
A total of 26 Australian schools with 2190 students (mean age: 13.3 years) were randomized to receive: universal prevention (Climate Schools); selective prevention (Preventure); combined prevention (Climate Schools and Preventure; CAP); or health education as usual (control). Primary outcomes were alcohol use, binge drinking and alcohol-related harms at 6, 12 and 24 months.
Climate, Preventure and CAP students demonstrated significantly lower growth in their likelihood to drink and binge drink, relative to controls over 24 months. Preventure students displayed significantly lower growth in their likelihood to experience alcohol harms, relative to controls. While adolescents in both the CAP and Climate groups demonstrated slower growth in drinking compared with adolescents in the control group over the 2-year study period, CAP adolescents demonstrated faster growth in drinking compared with Climate adolescents.
Findings support universal, selective and combined approaches to alcohol prevention. Particularly novel are the findings of no advantage of the combined approach over universal or selective prevention alone.
With the changing distribution of infectious diseases, and an increase in the burden of non-communicable diseases, low- and middle-income countries, including those in Africa, will need to expand their health care capacities to effectively respond to these epidemiological transitions. The interrelated risk factors for chronic infectious and non-communicable diseases and the need for long-term disease management, argue for combined strategies to understand their underlying causes and to design strategies for effective prevention and long-term care. Through multidisciplinary research and implementation partnerships, we advocate an integrated approach for research and healthcare for chronic diseases in Africa.
Background: The present study explored the reliability, validity, and factor structure of a modified version of the Moral Disengagement Scale (MDS), which comprehensively assesses proneness to disengage from different forms of conduct specific to Australian adolescents. Methods: A sample of 452 students (Mage = 12.79; SD = 1.93) completed the modified MDS and the Australian Self-Report Delinquency Scale. A multistep approach was used to evaluate the factor structure of the MDS. The sample was divided into exploratory (n = 221) and cross-validation samples (n = 231). Principal component analysis was conducted with the exploratory sample and multiple factor solutions compared to determine the optimal factor structure of the modified MDS. The final factor solution was confirmed in the cross-validation sample using confirmatory factor analysis. Internal consistency of the final scale and convergent validity with the delinquency questionnaire was also assessed. Results: Analyses resulted in a 22-item MDS for use in Australia, with four factors mapping onto the four conceptual categories of moral disengagement. The individual subscales demonstrated adequate to good internal consistency, and the total scale also demonstrated high internal consistency (α = 0.87). Convergent validity of the scale was established. Conclusions: The 22-item Australian MDS is a reliable and valid instrument for use within an Australian population.
Few studies have explored therapists’ views on computerized cognitive behavioural therapy (cCBT) and this study aimed to provide an in-depth understanding of accredited therapists’ views on cCBT's role in treating depression. Twelve therapists constituted this self-selected sample (eight female, four male). Mean age was 52 years (range 46–61). The data obtained from a semi-structured questionnaire were analysed using thematic analysis. Three themes were identified and discussed: (1) the standardized nature of cCBT for depression, (2) the importance of the therapeutic relationship in cCBT, and (3) the pros and cons with cCBT as an alternative to CBT. The therapists in this study emphasized that innovations in CBT delivery formats (e.g. internet-based, computerized) show promise. However, participants expressed some views that clash with the evidence-based viewpoint. More work is needed to improve the implementation of evidence-based practice and policy.
Toxigenic strains of Vibrio cholerae serogroups O1 and O139 have caused cholera epidemics, but other serogroups – such as O75 or O141 – can also produce cholera toxin and cause severe watery diarrhoea similar to cholera. We describe 31 years of surveillance for toxigenic non-O1, non-O139 infections in the United States and map these infections to the state where the exposure probably originated. While serogroups O75 and O141 are closely related pathogens, they differ in how and where they infect people. Oysters were the main vehicle for O75 infection. The vehicles for O141 infection include oysters, clams, and freshwater in lakes and rivers. The patients infected with serogroup O75 who had food traceback information available ate raw oysters from Florida. Patients infected with O141 ate oysters from Florida and clams from New Jersey, and those who only reported being exposed to freshwater were exposed in Arizona, Michigan, Missouri, and Texas. Improving the safety of oysters, specifically, should help prevent future illnesses from these toxigenic strains and similar pathogenic Vibrio species. Post-harvest processing of raw oysters, such as individual quick freezing, heat-cool pasteurization, and high hydrostatic pressurization, should be considered.
The status and potential of aquaculture is considered as part of a broader food landscape of wild aquatic and terrestrial food sources. The rationale and resource base required for the development of aquaculture are considered in the context of broader societal development, cultural preferences and human needs. Attention is drawn to the uneven development and current importance of aquaculture globally as well as its considerable heterogeneity of form and function compared with established terrestrial livestock production. The recent drivers of growth in demand and production are examined and the persistent linkages between exploitation of wild stocks, full life cycle culture and the various intermediate forms explored. An emergent trend for sourcing aquaculture feeds from alternatives to marine ingredients is described and the implications for the sector with rapidly growing feed needs discussed. The rise of non-conventional and innovative feed ingredients, often shared with terrestrial livestock, are considered, including aquaculture itself becoming a major source of marine ingredients. The implications for the continued expected growth of aquaculture are set in the context of sustainable intensification, with the challenges that conventional intensification and emergent integration within, and between, value chains explored. The review concludes with a consideration of the implications for dependent livelihoods and projections for various futures based on limited resources but growing demand.
The yields of spring barley during a medium-term (7 years) compost and slurry addition experiment and the soil carbon (C) and nitrogen (N) contents, bacterial community structure, soil microbial biomass and soil respiration rates have been determined to assess the effects of repeated, and in some cases very large, organic amendments on soil and crop parameters. For compost, total additions were equivalent to up to 119 t C/ha and 1·7 t N/ha and for slurry they were 25 t C/ha and 0·35 t N/ha over 7 years, which represented very large additions compared to control soil C and N contents (69 t C/ha and 0·3 t N/ha in the 0–30 cm soil depth). There was an initial positive response to compost and slurry addition on barley yield, but over the experiment the yield differential between the amounts of compost addition declined, indicating that repeated addition of compost at a lower rate over several years had the same cumulative effect as a large single compost application. By the end of the experiment it was clear that the addition of compost and slurry increased soil C and N contents, especially towards the top of the soil profile, as well as soil respiration rates. However, the increases in soil C and N contents were not proportional to the amount of C and N added, suggesting either that: (i) a portion of the added C and N was more vulnerable to loss; (ii) that its addition rendered another C or N pool in the soil more susceptible to loss; or (iii) that the C inputs from additional crop productivity did not increase in line with the organic amendments. Soil microbial biomass was depressed at the highest rate of organic amendment, and whilst this may have been due to genuine toxic or inhibitory effects of large amounts of compost, it could also be due to the inaccuracy of the substrate-induced respiration approach used for determining soil biomass when there is a large supply of organic matter. At the highest compost addition, the bacterial community structure was significantly altered, suggesting that the amendments significantly altered soil community dynamics.
Introduction: Substance use and unstable housing are associated with heavy use of the Emergency Department (ED). This study examined the impact of substance use and unstable housing on the probability of future ED use. Methods: Case-control study of patients presenting to an urban ED. Patients were eligible if they were unstably housed for the past 30 days, and/or if their chief complaint was related to substance use. Following written informed consent, patients completed a baseline survey and health care use was tracked via electronic medical records for the next six months. Controls were enrolled in a 1:4 ratio. More than 2 ED visits during the follow-up was pre-specified as a measure of excess ED use. Descriptive analyses included proportions and medians with interquartile ranges (IQR). Binomial logistic regression models were used to estimate the impact of housing status, high-risk alcohol use (AUDIT) and drug use (DUDIT), and combinations of these factors on subsequent acute care system contacts (ED visits + admissions). We controlled for age, gender, comorbidities at baseline, and baseline presenting acuity. Results: 41 controls, 46 substance using, 91 unstably housed, and 31 both unstably housed and substance using patients were enrolled (n = 209). Median ED visits during follow up were 0 (IQR: 0-1.0) for controls, 1.0 (IQR: 0-3.3) for substance using, 1.0 (IQR: 0-4.0) for unstably housed and 4 (IQR: 2-12.3) for unstably housed and substance using patients. The median acute care system contacts over the same period was 1.0 (IQR 0-2.0) for controls, 1.0 (IQR: 0-4.0) for substance using, 1.0 (IQR: 0-5.0) for unstably housed and 4.5 (IQR: 2.8-14.3) for unstably housed and substance using patients. Being unstably housed was the factor most strongly associated with having > 2 ED visits (b=3.288, p<0.005) followed by high-risk alcohol and drug use (b=2.149, p<0.08); high risk alcohol use alone was not significantly associated with ED visits (b=1.939, p<0.1). The number of comorbidities present at baseline was a small but statistically significant additional risk factor (b=0.478, p<0.05). The model correctly predicted 70.1% of patients’ ED utilization status. Conclusion: Unstable housing is a substantial risk factor for ED use; high-risk alcohol and drug use, and comorbidities at baseline increased this risk. The intensity of excess ED use was greatest in patients who were unstably housed and substance using.
The president calls attention to the large and increasing membership of Commission 12 and the policy of concentrating in it all matters relating to the sun. The result makes it comparable in breadth of field and in membership to the former Union for Co-operation in Solar Research. The main point in favour of this policy is the increased interest in the meetings of the Commission and the larger number of individuals reached compared with the meetings of small committees. One recalls the general sessions of the Solar Union in which each one present felt himself a part of the Union and in real touch with the work of different sections and after the discussions went away with fuller knowledge of what it was all about. This was a valuable result not attained to the same degree from the general sessions of the present Union, but in a measure it does follow from the meetings of the Solar Physics Committee. On the other hand the question may be raised whether or not the merging of independent commissions into subdivisions of a large commission lessens their interest to an extent not balanced by the advantages. If the present policy holds, it seems to the president that a re-organisation of Commission 12 is advisable by which more responsibility is laid upon the directors of centres. The basis of membership in the Commission may well be considered and recommendations formulated for transmission to the Executive Committee.
The maintenance of the physical and emotional safety of children about to be returned to their families following serious abuse is a complex and significant problem. This paper describes a treatment offered to such families which makes use of a residential setting, and which involved intensive work over the period of a week. This approach was cost effective, allowed for greater creativity by child protection workers, and impacted significantly on the lives of the families. This paper offers a philosophical as well as practical framework for treating at risk families in which a child is about to be returned.
One looks back with appreciation to the brilliant teachers, but with gratitude to those who touched our human feelings. The curriculum is so much necessary raw material, but warmth is the vital element for the growing plant and for the soul of the child.
– Carl Jung
Actively caring for people (AC4P) of course includes children we commonly refer to as “preschoolers,” ages 3–5 years. How do we best launch these children for lifelong success? Kindergarten can be exciting, yet perhaps overwhelming or possibly scary – especially today, as many scholars cite the academic rigor of kindergarten. The mission is no longer simply learning to play and relate with others. Now kindergarten children must master certain academic requirements.
More children are engaged in preschool activities today, perhaps due to increased kindergarten entry requirements. Currently, no federal or state mandates for preschool exist, but approximately half of U.S. children aged 3–4 are enrolled in some sort of preschool/daycare experience. Critical questions arise: How important is the preschool experience, and what characteristics define an effective preschool program?
THE IMPORTANCE OF PRESCHOOL
This chapter explores the AC4P behaviors of teachers that can promote early learning in preschool settings. We discuss how teachers can learn to create an AC4P culture in their classrooms to effectively promote early childhood development. Consistent with the theme of this book, information contained in this chapter clearly aligns with the basic principles of the AC4P Movement introduced in Chapter 2.
Children of preschool age differ considerably in their readiness or ability to learn to read and do math. These skills are highly predictive of later educational success. With regard to reading, for example, early elementary years appear to be critical for learning basic reading skills. In later grades, elementary school teachers transition from teaching students how to read to expecting students to acquire knowledge and learn through reading.
Perhaps you recall how your fifth- and-sixth-grade teachers began asking you to read longer sections of textbooks as homework and to learn new and exciting information in domains such as science and history through the process of reading. Imagine that experience had you not yet learned how to read.