A comparison of some estimators of error probabilities in discriminant analysis

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Properties Of Logistic Regression Models With Correlated Observations

The correlated logistic regression model, a new model for correlated binary observations in the presence of covariates, is introduced and its relationship with other logistic models established. Comparisons are made with other models for correlated binary outcomes, particularly those that allow unit-specific covariates. A conditional model is derived and shown to be equivalent to a well-known model used in case-control studies.;Properties of several estimators of the regression parameter are investigated. Consistency of the unconditional and conditional maximum likelihood estimators is established and expressions derived for the asymptotic variance of the two estimators under the full model and also under a simpler model. Two other estimators, namely, the estimator obtained by using the usual logistic model and an estimator obtained by using dummy variables in the usual logistic model, are investigated. These two estimators are shown to be, in general, asymptotically biased. Some conditions are given for consistency of the two estimators. Expressions for the asymptotic variances of the two estimators, and the misspecification factors for their estimated variance, are obtained.;In the case of a single binary covariate, it is shown that the bias of the usual estimator is large even for moderate sample size, whereas the bias of the dummy variables estimator becomes small for moderate sample size. It is shown that, although in special cases the usual and dummy variables estimators may have higher asymptotic relative efficiency than the maximum likelihood estimator, unless both the intraclass correlation of the covariate and the residual intraclass correlation are close to zero, the usual, dummy variables and conditional estimators are, in general, not highly efficient. In particular, the asymptotic relative efficiency of the conditional estimator may be quite low.;Examples are given with simulated and real data showing how the usual, dummy variables and conditional estimators produce falsely significant test statistics

Loneliness and Deprivation: The Case of Roman Catholic Priests

Using Roman Catholic Priests as a test in order to control for deprivation in relationships of intimacy while maximizing the need for social network relationships, an examination was made of their differential experience of loneliness. The evidence suggested repeatedly that priests were more likely to experience loneliness as a serious problem when they perceived that the social network which they regarded as most significant in their lives (the Church) placed some kind of structural limitation on the extent of their involvement in it. Factors, for example, which help determine the individual priest\u27s place in the structure of the Church are: type of assignment, length of time ordained, and degree of integration into the network through mutual commitment; all of these factors correlate significantly with the experience of loneliness. For priests experiencing serious loneliness, there were further significant correlations with a perceived deficit in intimacy, an expressed need for sexual intimacy, a desire to marry, and more frequent dating behavior. While causal sequences could not be established with certainty, the use of Guttman scaling techniques and a logical ordering of the variables suggests strongly that an emotional response (in this case an exaggerated search for intimate relationships) may have been triggered by social deprivation (network exclusion) rather than by an emotional deprivation (in intimacy) as might have been expected. Such a possibility has far-reaching implications and calls for further research. If an exaggerated search for intimate relationships can be triggered by social network deprivation, that might shed light on a variety of other phenomena such as promiscuity and rape, especially in urban, industrialized societies whose character is such that secondary relationehips become more pervasive and achieve such great importance in the minds and daily lives of the people

Innovation and Fringe Benefits

77 pagesThe focus of this particular study is on collective bargaining, or more generally, industrial sociology. Fringe benefits, the particular aspect of collective bargaining in question, were chose not so much for their present popularity as for their ability to characterize specific instances of innovation in a particular setting – collective bargaining – and for the opportunity to investigate the relation of innovative fringe benefits to the labor imporovement

Moderated online social therapy for carers of young people recovering from firstepisode psychosis: study protocol for a randomised controlled trial

Background: First-episode psychosis most often has its onset during late adolescence. In caring for the young person, families endure high levels of stress and depression. Meanwhile, the social networks of families often erode. Our group has previously shown that family cognitive behaviour therapy (CBT) leads to significantly improved perceived stress compared with specialist first-episode treatment as usual; however, there are well-known barriers to the dissemination of effective family interventions. To address this, we have developed a novel online intervention entitled ‘Altitudes’ that fully integrates purpose-built online social networking, expert and peer moderation, and evidence-based psychoeducation within a single application. The primary aim of this trial is to evaluate the effectiveness of Altitudes in reducing stress in carers over a 6-month period. Methods/design: We describe here a single-blinded cluster randomised controlled trial (cRCT) with permutated blocks. The clusters comprise individual families. The two treatment conditions include Altitudes plus Specialist Treatment as Usual (STAU) and STAU alone. Altitudes involves participation in our novel online programme whereas STAU comprises specialist family work at the Early Psychosis Prevention and Intervention Centre (EPPIC), Melbourne, Australia. We aim to recruit 160 family members of young, 15–27 year-old, patients registered for treatment for firstepisode psychosis (FEP) at EPPIC. The design includes two assessment time points, namely, baseline and 6-month follow-up. The study is due for completion within 2 years including an 18-month recruitment period and a 6- month treatment phase. The primary outcome is carers’ perceived stress at 6 months. Secondary outcome measures include a biomarker of stress, depressive symptoms, worry, substance use, loneliness, social support, satisfaction with life, and a range of measures that tap into coping resources. We seek to gain a dynamic picture of carer stress through our Smartphone Ecological Momentary Assessment (SEMA) tool. Discussion: This is the first randomised controlled trial designed to evaluate an online intervention for carers of young people recovering from FEP. It has the potential to produce evidence in support of a highly novel, accessible, and cost-effective intervention to reduce stress in carers who are providing support to young people at a critical phase in their recovery from psychosis. Trial registration: Australian New Zealand Clinica

Comparison of brush and biopsy sampling methods of the ileal pouch for assessment of mucosa-associated microbiota of human subjects

BACKGROUND: Mucosal biopsy is the most common sampling technique used to assess microbial communities associated with the intestinal mucosa. Biopsies disrupt the epithelium and can be associated with complications such as bleeding. Biopsies sample a limited area of the mucosa, which can lead to potential sampling bias. In contrast to the mucosal biopsy, the mucosal brush technique is less invasive and provides greater mucosal coverage, and if it can provide equivalent microbial community data, it would be preferable to mucosal biopsies. RESULTS: We compared microbial samples collected from the intestinal mucosa using either a cytology brush or mucosal biopsy forceps. We collected paired samples from patients with ulcerative colitis (UC) who had previously undergone colectomy and ileal pouch anal anastomosis (IPAA), and profiled the microbial communities of the samples by sequencing V4-V6 or V4-V5 16S rRNA-encoding gene amplicons. Comparisons of 177 taxa in 16 brush-biopsy sample pairs had a mean R(2) of 0.94. We found no taxa that varied significantly between the brush and biopsy samples after adjusting for multiple comparisons (false discovery rate ≤0.05). We also tested the reproducibility of DNA amplification and sequencing in 25 replicate pairs and found negligible variation (mean R(2) = 0.99). A qPCR analysis of the two methods showed that the relative yields of bacterial DNA to human DNA were several-fold higher in the brush samples than in the biopsies. CONCLUSIONS: Mucosal brushing is preferred to mucosal biopsy for sampling the epithelial-associated microbiota. Although both techniques provide similar assessments of the microbial community composition, the brush sampling method has relatively more bacterial to host DNA, covers a larger surface area, and is less traumatic to the epithelium than the mucosal biopsy

Terahertz Faraday Rotation of SrFe 12 O 19 Hexaferrites Enhanced by Nb Doping

From American Chemical Society via Jisc Publications RouterHistory: received 2022-07-21, rev-recd 2022-09-25, accepted 2022-09-26, pub-electronic 2022-10-04, asap 2022-10-04, issue-pub 2022-10-19Article version: VoRPublication status: PublishedFunder: National Natural Science Foundation of China; doi: 10.13039/501100001809; Grant(s): 12174146Funder: National Natural Science Foundation of China; doi: 10.13039/501100001809; Grant(s): 91963201Funder: China Scholarship Council; doi: 10.13039/501100004543; Grant(s): 201806370199Funder: Vedeck? Grantov? Agent?ra M?VVa? SR a SAV; doi: 10.13039/501100006109; Grant(s): 2/0034/23Funder: Vedeck? Grantov? Agent?ra M?VVa? SR a SAV; doi: 10.13039/501100006109; Grant(s): 2/0038/20Funder: Higher Education Discipline Innovation Project; doi: 10.13039/501100013314; Grant(s): B2006The magneto-optical and dielectric behavior of M-type hexaferrites as permanent magnets in the THz band is essential for potential applications like microwave absorbers and antennas, while are rarely reported in recent years. In this work, single-phase SrFe12–x Nb x O19 hexaferrite ceramics were prepared by the conventional solid-state sintering method. Temperature dependence of dielectric parameters was investigated here to determine the relationship between dielectric response and magnetic phase transition. The saturated magnetization increases by nearly 12%, while the coercive field decreases by 30% in the x = 0.03 composition compared to that of the x = 0.00 sample. Besides, the Nb substitution improves the magneto-optical behavior in the THz band by comparing the Faraday rotation parameter from 0.75 (x = 0.00) to 1.30 (x = 0.03). The changes in the magnetic properties are explained by a composition-driven increase of the net magnetic moment and enhanced ferromagnetic exchange coupling. The substitution of the donor dopant Nb on the Fe site is a feasible way to obtain multifunctional M-type hexaferrites as preferred candidates for permanent magnets, sensors, and other electronic devices