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For continuous distributions associated with dichotomous item scores, the proportion of common-factor variance in the test, H2, may be expressed as a function of intercorrelations among items. H2 is somewhat larger than the coefficient a except when the items have only one common factor and its loadings are restricted in value. The dichotomous item scores themselves are shown not to have a factor structure, precluding direct interpretation of the Kuder-Richardson coefficient, rK-R, in terms of factorial properties. The value of rK-R is equal to that of a coefficient of equivalence, H2Φ, when the mean item variance associated with common factors equals the mean interitem covariance. An empirical study with synthetic test data from populations of varying factorial structure showed that the four parameters mentioned may be adequately estimated from dichotomous data.
The presence of an intraluminal thrombus in acutely symptomatic carotid stenosis is thought to represent a high-risk lesion for short-term stroke reccurrence though evidence on natural history and treatment is lacking, leading to equipoise and much variation in practice. The objective of this study was to map these variations in practice (medical management and timing of revascularization), determine the considerations that influence clinician decision-making in this condition and gather opinions that inform the development and design of future trials in the area.
Methods:
This was a mixed-methods study using both quantitative survey methods and qualitative interview-based methods. International perspectives were gathered by distributing a case-based survey via the “Practice Current” section of Neurology: Clinical Practice and interviewing international experts using established qualitative research methods.
Results:
The presence of an intraluminal thrombus significantly increased the likelihood of using a regimen containing anticoagulation agents (p < 0.001) in acutely symptomatic carotid stenosis in the case-based survey. Themes that emerged from qualitative interview analysis were therapeutic uncertainty regarding anticoagulation, decision to reimage, revascularization choices and future trial design and anticipated challenges.
Conclusion:
Results of this study demonstrate a preference for anticoagulation and delayed revascularization after reimaging to examine for clot resolution, though much equipoise remains. While there is interest from international experts in future trials, further study is needed to understand the natural history of this condition in order to inform trial design.
We introduce a generalization of immanants of matrices, using partition algebra characters in place of symmetric group characters. We prove that our immanant-like function on square matrices, which we refer to as the recombinant, agrees with the usual definition for immanants for the special case whereby the vacillating tableaux associated with the irreducible characters correspond, according to the Bratteli diagram for partition algebra representations, to the integer partition shapes for symmetric group characters. In contrast to previously studied variants and generalizations of immanants, as in Temperley–Lieb immanants and f-immanants, the sum that we use to define recombinants is indexed by a full set of partition diagrams, as opposed to permutations.
We review successes and challenges from five recent subglacial bedrock drilling campaigns intended to find evidence for Antarctic Ice Sheet retreat during warm periods in the geologic past. Insights into times when the polar ice sheets were smaller than present serve as guiding information for modeling efforts that aim to predict the rate and magnitude of future sea level rise that would accompany major retreat of the Antarctic Ice Sheet. One method to provide direct evidence for the timing of deglaciations and minimum extent of prior ice sheets is to extract subglacial bedrock cores for cosmogenic nuclide analysis from beneath the modern ice sheet surface. Here we summarize the lessons learned from five field seasons tasked with obtaining bedrock cores from shallow depths (<120 m beneath ice surface) across West Antarctica since 2016. We focus our findings on drilling efforts and technology and geophysical surveys with ground-penetrating radar. Shallow subglacial drilling provides a high risk, high reward means to test for past instabilities of the Antarctic Ice Sheet, and we highlight key challenges and solutions to increase the likelihood of success for future subglacial drilling efforts in polar regions.
• This chapter disrupts the academy by explaining how the experiences of people with lived experience of suicidal ideation should be considered and addressed in collaborative research on this topic.
• People with lived experience must have agency and equality with project team members throughout the research and co-design processes, with the same people with lived experience involved throughout.
• We should be encouraged to share our experiences to challenge traditional research-based and practice paradigms that often fail to legitimise subjective experience and experiential insight.
• Suicide should not be viewed as a disease in search of a cure. Given the life experiences and circumstances of individuals with suicidal ideation, it can seem to be a perfectly rational choice, and their reality must be validated and respected as ‘normal’ before help is offered.
Introduction
Suicide is the leading cause of death for Australians aged 15 to 44 years (Australian Bureau of Statistics, 2020). Between 50 and 60 per cent of individuals who die by suicide ‘fly under the radar’, that is, without receiving formal mental health care (Johnston et al, 2009). Most have been in contact with services for physical health issues in the days or months preceding an attempt but did not receive help for their suicidal thoughts or mental health problems (Stene-Larsen and Reneflot, 2019). Little is known about individuals at risk of suicide who are not receiving mental health care.
In 2021, the Black Dog Institute, a mental health research organisation in Sydney, Australia, undertook a four-year research project to develop a person-centred service for individuals at risk of suicide but not in care. The project consisted of multiple phases and several stakeholders including a project manager, institute research teams, a design team, a lived experience team and representatives from external organisations. The project aimed to adhere to a co-design methodology and a governance structure was created with a Core Co-Design team established at the outset. At the time of writing this chapter (August 2022), the first three phases had been completed.
The office evaluation of the infertile male involves a comprehensive history and physical structured to uncover all potential causes including congenital, medical, surgical, environmental, genetic, and psychosocial etiologies. The physical exam begins with the patient’s general appearance, body habitus, and progresses to the genital exam in which the testicles are examined for size, consistency, and location. Prior surgical scars, absence of the vas deferens, or the presence of varicoceles may be identifiable causes of infertility. The semen analysis is the cornerstone laboratory evaluation of the male undergoing an infertility workup. The semen is evaluated for several key parameters including volume as well as sperm concentration, number, motility, and form. An endocrine evaluation is indicated in men with oligospermia, azoospermia, or a history of physical examination findings suggestive of hormonal abnormalities including sexual dysfunction, decreased libido, or physical evidence of impair androgenization. Pending the initial workup genetic testing may be indicated.
Recent evidence from case reports suggests that a ketogenic diet may be effective for bipolar disorder. However, no clinical trials have been conducted to date.
Aims
To assess the recruitment and feasibility of a ketogenic diet intervention in bipolar disorder.
Method
Euthymic individuals with bipolar disorder were recruited to a 6–8 week trial of a modified ketogenic diet, and a range of clinical, economic and functional outcome measures were assessed. Study registration number: ISRCTN61613198.
Results
Of 27 recruited participants, 26 commenced and 20 completed the modified ketogenic diet for 6–8 weeks. The outcomes data-set was 95% complete for daily ketone measures, 95% complete for daily glucose measures and 95% complete for daily ecological momentary assessment of symptoms during the intervention period. Mean daily blood ketone readings were 1.3 mmol/L (s.d. = 0.77, median = 1.1) during the intervention period, and 91% of all readings indicated ketosis, suggesting a high degree of adherence to the diet. Over 91% of daily blood glucose readings were within normal range, with 9% indicating mild hypoglycaemia. Eleven minor adverse events were recorded, including fatigue, constipation, drowsiness and hunger. One serious adverse event was reported (euglycemic ketoacidosis in a participant taking SGLT2-inhibitor medication).
Conclusions
The recruitment and retention of euthymic individuals with bipolar disorder to a 6–8 week ketogenic diet intervention was feasible, with high completion rates for outcome measures. The majority of participants reached and maintained ketosis, and adverse events were generally mild and modifiable. A future randomised controlled trial is now warranted.
Whereas the beneficial effect of antiplatelet therapy for recurrent stroke prevention has been well established, uncertainties remain regarding the optimal antithrombotic regimen for recently symptomatic carotid stenosis. We sought to explore the approaches of stroke physicians to antithrombotic management of patients with symptomatic carotid stenosis.
Methods:
We employed a qualitative descriptive methodology to explore the decision-making approaches and opinions of physicians regarding antithrombotic regimens for symptomatic carotid stenosis. We conducted semi-structured interviews with a purposive sample of 22 stroke physicians (11 neurologists, 3 geriatricians, 5 interventional-neuroradiologists, and 3 neurosurgeons) from 16 centers on four continents to discuss symptomatic carotid stenosis management. We then conducted thematic analysis on the transcripts.
Results:
Important themes revealed from our analysis included limitations of existing clinical trial evidence, competing surgeon versus neurologist/internist preferences, and the choice of antiplatelet therapy while awaiting revascularization. There was a greater concern for adverse events while using multiple antiplatelet agents (e.g., dual-antiplatelet therapy (DAPT)) in patients undergoing carotid endarterectomy compared to carotid artery stenting. Regional variations included more frequent use of single antiplatelet agents among European participants. Areas of uncertainty included antithrombotic management if already on an antiplatelet agent, implications of nonstenotic features of carotid disease, the role of newer antiplatelet agents or anticoagulants, platelet aggregation testing, and timing of DAPT.
Conclusion:
Our qualitative findings can help physicians critically examine the rationale underlying their own antithrombotic approaches to symptomatic carotid stenosis. Future clinical trials may wish to accommodate identified variations in practice patterns and areas of uncertainty to better inform clinical practice.
In 2011, Guillera [‘A new Ramanujan-like series for $1/\pi ^2$’, Ramanujan J.26 (2011), 369–374] introduced a remarkable rational ${}_{7}F_{6}( \frac {27}{64} )$-series for ${1}/{\pi ^2}$ using the Wilf–Zeilberger (WZ) method, and Chu and Zhang later proved this evaluation using an acceleration method based on Dougall’s ${}_{5}F_{4}$-sum. Another proof of Guillera’s ${}_{7}F_{6}( \frac {27}{64} )$-series was given by Guillera in 2018, and this subsequent proof used a recursive argument involving Dougall’s sum together with the WZ method. Subsequently, Chen and Chu introduced a q-analogue of Guillera’s ${}_{7}F_{6}( \frac {27}{64} )$-series. The many past research articles concerning Guillera’s ${}_{7}F_{6}( \frac {27}{64} )$-series for ${1}/{\pi ^2}$ naturally lead to questions about similar results for other mathematical constants. We apply a WZ-based acceleration method to prove new rational ${}_{7}F_{6}( \frac {27}{64} )$- and ${}_{6}F_{5}( \frac {27}{64} )$-series for $\sqrt {2}$.
About one in every four Australian employees is a casual. The casual share has doubled over the past decade and continues to expand. This paper catalogues the growth of casual employment and discusses the characteristics of casual jobs and of those in casual jobs. The key analytical issue discussed is whether casual employment is a transitional employment arrangement on the road towards permanent employment conditions. Alternatively, is it a trap which is associated with job insecurity, low earnings and spells outside of employment? Although the evidence is partial and circumstantial, casual employment is a bridge for some and a trap for others. In particular, for those who wish to beak out of unemployment, casual employment is unlikely to be a transitional point on the road to a permanent job. This finding has important implications for the design of labour market programs.
About a year into Trump’s presidency, I sat on a flight home from Europe next to a twenty-year veteran of the US State Department. I asked him how things were going since Trump’s Secretary of State, Rex Tillerson, had taken charge. He hesitated for a minute but then explained that things weren’t going that well. Neither Trump nor Tillerson listened much to their career civil service professionals. Morale was as low as he’d ever seen it, several senior people had decided to take early retirement, and those remaining were often at odds with administration policies. He also said that because the State Department’s reputation had been tarnished because of Trump’s insulting and often isolationist foreign policies, it was having trouble recruiting young people to work there – a problem, he explained, that was creating a generational vacuum of expertise that would remain for years even after Trump was gone.
Donald J. Trump was sworn in as the forty-fifth president of the United States on January 20, 2017. How he won the presidency is the subject of this chapter. It is an important story for us because it foreshadows some of the leadership characteristics that he brought to the White House to launch his attack on the “deep state.” It’s also an important story because Trump’s election reflected a tipping point in American politics – a set of structural conditions and national anxieties that had developed gradually over several decades. Trump benefited from other tipping points once he became president, but this was the one that launched his startling rise to the presidency in the first place. Trump recognized and exploited this unique political opportunity to seize power.1 He was a maven whose inspirational promises and appeal to voters fit the times like a glove, enabling him to pursue his agenda for radical institutional change.
Upon leaving the Constitutional Convention in 1787, Benjamin Franklin is supposed to have been asked whether the framers had given us a monarchy or a republic. As legend has it, Franklin’s reply was short and sweet: “A republic, if you can keep it.” The principal difference between the two is the presence in a republic of free and fair elections – the institutional core of any democracy.