Miracle-dz/UniFAR-FTUs huggingface dataset:
Magnitude least squares optimization for parallel radio frequency excitation design demonstrated at 7 Tesla with eight channels

Spatially tailored radio frequency (RF) excitations accelerated with parallel transmit systems provide the opportunity to create shaped volume excitations or mitigate inhomogeneous B1 excitation profiles with clinically relevant pulse lengths. While such excitations are often designed as a least‐squares optimized approximation to a target magnitude and phase profile, adherence to the target phase profile is usually not important as long as the excitation phase is slowly varying compared with the voxel dimension. In this work, we demonstrate a method for a magnitude least squares optimization of the target magnetization profile for multichannel parallel excitation to improve the magnitude profile and reduce the RF power at the cost of a less uniform phase profile. The method enables the designer to trade off the allowed spatial phase variation for the improvement in magnitude profile and reduction in RF power. We validate the method with simulation studies and demonstrate its performance in fourfold accelerated two‐dimensional spiral excitations, as well as for uniform in‐plane slice selective parallel excitations using an eight‐channel transmit array on a 7T human MRI scanner. The experimental results are in good agreement with the simulations, which show significant improvement in the magnitude profile and reductions in the required RF power while still maintaining negligible intravoxel phase variation. Magn Reson Med 59:908–915, 2008. © 2008 Wiley‐Liss, Inc.
Majorana Positivity and the Fermion Sign Problem of Quantum Monte Carlo Simulations.

The sign problem is a major obstacle in quantum Monte Carlo simulations for many-body fermion systems. We examine this problem with a new perspective based on the Majorana reflection positivity and Majorana Kramers positivity. Two sufficient conditions are proven for the absence of the fermion sign problem. Our proof provides a unified description for all the interacting lattice fermion models previously known to be free of the sign problem based on the auxiliary field quantum Monte Carlo method. It also allows us to identify a number of new sign-problem-free interacting fermion models including, but not limited to, lattice fermion models with repulsive interactions but without particle-hole symmetry, and interacting topological insulators with spin-flip terms.
In vivo quantification of T1, T2, and apparent diffusion coefficient in the mouse retina at 11.74T

MRI has recently been used for noninvasive examination of retinal structure and function in rats and cats. However, the advantages of quantitative high‐resolution MRI of retina from mice have not yet been explored. In the present study, T1 and T2 relaxation time constants and the directional apparent diffusion coefficient (ADC) in the retina of C57/BL6 mice were measured. Three MR‐detected retina layers and a MR‐detected choroid layer were observed on both T1‐ and T2‐weighted images at an image resolution of 47 × 47 × 400 μm3. The significantly higher ADC parallel to than that perpendicular to the optic nerve in the MR‐detected outer retina layer at the central retina reflects the known cellular organization of the photoreceptor cells. This study establishes, for the first time, normative metrics of T1, T2, and ADC of the mouse retina. These MR parameters are expected to be useful in future evaluation of developmental and pathological alterations of retinal cell layers in mice. Magn Reson Med 59:731–738, 2008. © 2008 Wiley‐Liss, Inc.
Gender Role, Life Satisfaction, and Wellness: Androgyny in a Southwestern Ontario Sample*

RÉSUMÉ Dans cette étude, nous avons effectué des recherches sur les relations entre le rôle sexuel et le fonctionnement physique autodéclaré, à partir d’un échantillon d’aînés vivant dans la communauté. Cent deux participants ont été recrutés (55 femmes, 47 hommes) dans les associations pour personnes âgées de Windsor, Ontario. Nous avons mené des analyses de variance pour chacun des sexes afin de comparer l’autoévaluation du fonctionnement physique, du bien-être et de la satisfaction de vivre des participants qui diffèrent dans la classification de leur rôle sexuel. Pour ce qui est des femmes âgées classées comme androgynes, le rôle sexuel avait des effets importants sur le bien-être général et la satisfaction de vivre, mais n’avait pas d’effet sur le fonctionnement physique autodéclaré. Venant à l’appui du modèle androgénique d’ajustement optimal de Bem, les analyses a posteriori ont révélé que les femmes qui se sont autodéclarées androgynes ont un meilleur niveau global de bien-être que les autres. L’autoévaluation du fonctionnement physique et du bien-être général chez les hommes âgés n’a pas démontré de différences importantes en fonction du rôle sexuel. Les limitations et les implications font l’objet de discussions. ABSTRACT This study investigated the relationships among gender role and self-reported health functioning in a sample of community dwelling older adults. One hundred and two (55 female, 47 male) participants were recruited through seniors’ associations in Windsor, Ontario. Analyses of variance were conducted separately by gender to compare the self-rated physical health functioning, wellness, and life satisfaction of participants differing on classification of their gender role. For older women classified as androgynous, gender role exhibited significant effects on general wellness and life satisfaction, but not on self-reported physical health functioning. In support of Bem’s androgyny model of optimal adjustment, post-hoc analyses revealed that women who rated themselves as androgynous reported better overall wellness levels than their peers. Older men’s self-reported physical health functioning and general wellness did not differ significantly by gender role. Limitations and implications are discussed.
The Canadian Community Health Survey as a Potential Recruitment Vehicle for the Canadian Longitudinal Study on Aging*

RÉSUMÉ Le but de l’Étude longitudinale canadienne sur le vieillissement (ÉLCV) est de recruter 50 000 participants âgés de 45 à 85 ans et de les suivre pendant 20 ans. Les processus d’échantillonnage et de recrutement pour une étude de cette envergure représentent d’importants défis. Statistique Canada a été approché pour collaborer avec l’ÉLCV dans le but de déterminer si l’Enquête sur la santé dans les collectivités canadiennes (ESCC) pourrait être utilisée comme véhicule de recrutement pour l’ÉLCV. Dans cette étude pilote réalisée en 2004, il a été déterminé que 63,8 pour cent et 75,8 pour cent des répondants accepteraient de partager leurs coordonnées et leurs réponses à l’ESCC avec l’ÉLCV, respectivement. Les réticences les plus souvent rapportées étaient reliées à la confidentialité, le manque d’intérêt et le niveau d’engagement demandé. Cette étude pilote a permis d’identifier quelques défis reliés à l’utilisation de l’ESCC comme véhicule de recrutement pour l’ÉLCV. ABSTRACT The goal of the Canadian Longitudinal Study on Aging (CLSA) is to recruit 50,000 participants aged 45 to 85 years of age and follow them for at least 20 years. The sampling and recruitment processes for a study of this scope and magnitude present important challenges. Statistics Canada was approached to collaborate with the CLSA with the goal of determining whether the Canadian Community Health Survey (CCHS) could be used as a recruitment vehicle for the CLSA. In this pilot study conducted in 2004, it was determined that 63.8 per cent and 75.8 per cent of the respondents agreed to share their contact information and their survey responses with the CLSA, respectively. The most commonly reported concerns were confidentiality/privacy issues, lack of interest, and commitment issues. This pilot study identified some challenges to the use of the CCHS as a recruitment vehicle for the CLSA.
Convertible manganese contrast for molecular and cellular MRI

We describe here the use of inorganic manganese based particles as convertible MRI agents. As has been demonstrated with iron oxide particles, manganese oxide and manganese carbonate particles can be internalized within phagocytotic cells, being subsequently shuttled to endosomes and/or lysosomes. As intact particles, only susceptibility‐induced MRI contrast is exhibited, most often seen as dark contrast in susceptibility‐weighted images. Modulation of MRI contrast is accomplished by the selective degradation of these particles within the endosomal and lysosomal compartments of cells. Upon particle deconstruction in the endosomes and lysosomes, the dissolved Mn2+ acts as a T1 agent, eliciting bright contrast in T1‐weighted images. This modulation of MRI contrast is demonstrated both in vitro in cells in culture, and also in vivo, in rat brain. These particles are the potential building blocks for an entire class of new environmentally responsive MRI contrast agents. Magn Reson Med 60:265–269, 2008. © 2008 Wiley‐Liss, Inc.
Lactate imaging with Hadamard‐encoded slice‐selective multiple quantum coherence chemical‐shift imaging

The ability to generate in vivo maps of lactate may have significant diagnostic utility in staging and treatment planning of a wide variety of cancers. The double selective multiple quantum filter technique (SelMQC) has been shown to be effective for nonlocalized detection of lactate with little or no interference from other signals. Here the SelMQC technique has been combined with longitudinal Hadamard slice selection and chemical shift imaging (CSI) to yield slice‐selective images of lactate. The technique is shown to be effective in phantoms and in WSU‐DLCL2 xenografts implanted in flanks of SCID mice. Tumors exhibited an annulus of elevated lactate concentration surrounding a necrotic tumor core. Magn Reson Med 60:299–305, 2008. © 2008 Wiley‐Liss, Inc.
Altered white matter diffusion anisotropy in normal and preterm infants at term‐equivalent age

To investigate white matter (WM) development, voxelwise analyses of diffusion tensor MRI (DTMRI) data, acquired from 12 very preterm and 11 preterm infants with gestational ages (GA) ranging from 25 to 29 and 29 to 32 weeks, respectively, and 10 newborn normal term infants were performed. T2 relaxation measures were also generated to assess brain water content. Compared with newborn term infants, very preterm infants were found to possess reduced fractional anisotropy (FA) within the frontal lobe, and a number of anterior and posterior commissural pathways. Preterm infants possessed reduced FA mainly within the posterior regions of the corpus callosum. Unexpectedly, we observed significantly reduced FA and increased T2 within a number of corticospinal projections in the newborn term infants compared to the preterm groups. This finding may reflect increased water concentration and/or a lowering of FA due to the presence of crossing interhemispheric WM projections. These findings indicate that care should be taken when interpreting FA indices without knowledge of the possible effects of water concentration in the newborn infant brain. Magn Reson Med 60:761–767, 2008. © 2008 Wiley‐Liss, Inc.
Managing congenital heart disease in the obstetric patient.

OBJECTIVE Cardiovascular disease is the major cause of pregnancy-related maternal mortality in the United States, and congenital heart disease (CHD) is the most common form of structural heart disease affecting women of childbearing age. Most females born with CHD will reach childbearing age and consider pregnancy. Adult CHD and maternal-fetal medicine (MFM) specialists managing women with CHD should provide preconception counseling, cardiovascular risk assessment prior to pregnancy that estimates maternal and fetal risk, management during pregnancy, and in the peripartum period and also know the potential complications and special circumstances that may occur in the post-partum period. This chapter will review the population at risk, patient risk prior to pregnancy, management during pregnancy, management in the peripartum and post-partum periods, and outline specific cardiovascular complications. The chapter will also briefly review some common or high-risk congenital cardiovascular lesions commonly encountered. CONCLUSION Management of patients with most forms of CHD encountered during pregnancy requires a multidisciplinary approach and careful team-based care to facilitate safe and appropriate management and pregnancy success.
Fast three‐dimensional 1H MR spectroscopic imaging at 7 Tesla using “spectroscopic missing pulse – SSFP”

The use of spectroscopic Missing Pulse ‐ SSFP (spMP‐SSFP) for fast three‐dimensional (3D) proton MR spectroscopic imaging (MRSI) at 7 Tesla (T) is demonstrated. Sequence modifications were required regarding the limits of the specific absorption rate as well as hardware limitations with respect to maximum B1 field strength and B0 gradient slew rate, as compared to previous studies performed at 3T. The combination of two spatially selective radiofrequency (RF) pulses (with orthogonal slice orientation) and a dual‐band chemical shift selective RF pulse for simultaneous water and lipid suppression proved to enable fast 3D MRSI measurements of the brain of healthy volunteers. Using a total measurement time of approximately 8.5 minutes and a nominal and real voxel size of 0.62 cm3 and 2.6 cm3, respectively, signals of N‐acetyl aspartate, total creatine, choline containing compounds, myo‐inositol, and glutamate+glutamine could be detected. Magn Reson Med, 2008. © 2008 Wiley‐Liss, Inc.
Transcutaneous Immunization Induces Antigen-Specific Antibody Responses in the Oral Cavity

Transcutaneous immunization is a new method of vaccination that utilizes a topical application of antigen to intact skin for induction of immune responses. In this study, we have assessed the potential for the application of transcutaneous immunization for the development of a novel vaccine- delivery system. When BALB/c mice were immunized with ovalbumin (OVA) by direct application to shaved skin, OVA-specific serum IgG antibody responses were induced ; however, none was induced in saliva. On the other hand, when OVA was given with cholera toxin (CT) as adjuvant, higher levels of OVA-specific serum IgG antibody responses were induced than that of OVA alone. Furthermore, OVA-specific IgG antibody responses were detected in the saliva of mice immunized with OVA plus CT. Antibody-forming cell (AFC) analysis confirmed the antibody titers by revealing significant numbers of OVA-specific IgG AFCs in the spleen and salivary gland. In addition, mononuclear cells from the spleen and cervical lymph nodes of mice immunized with OVA plus CT exhibited significant levels of proliferative responses when restimulated with OVA in vitro. These results indicate that transcutaneous immunization may be an effective vaccine delivery system for the induction of protein antigen-specific antibody responses in the oral cavity.
Reproductive ecology of the carnivorous plant Pinguicula moranensis (Lentibulariaceae).

The interaction of plants with pollinators can be a determinant of their reproductive fitness. However, information about the pollination biology of carnivorous plants is scarce. To increase knowledge of reproductive ecology of carnivorous plants we focused on Pinguicula moranensis. Specifically, based on the presence of large, zygomorphic and spurred flowers, we predicted higher reproductive fitness in cross-pollinated than in self-pollinated flowers. Within a plot of 51 m2 we characterised the reproductive phenology, including flower lifespan and stigmatic receptivity. We identified pollinators and their movement patterns within the plot. Breeding system was experimentally evaluated using hand-pollination (i.e. autonomous, self- and cross-pollination). Flowers of P. moranensis were visited by long-tongued pollinators, mainly members of the Lepidoptera. Hand-pollination experiments confirmed our prediction and suggest that flower traits might favour cross-pollination. We mainly discuss the implications of the patchy distribution of plants and behaviour of pollinators on gene movement in this plant species, as pollination between genetically related individuals could be occurring.
Improved residue function and reduced flow dependence in MR perfusion using least‐absolute‐deviation regularization

Cerebral blood flow (CBF) estimates derived from singular value decomposition (SVD) of time intensity curves from Gadolinium bolus perfusion‐weighted imaging are known to underestimate CBF, especially at high flow rates. We report the development of a model‐independent delay‐invariant deconvolution technique using least‐absolute‐deviation (LAD) regularization to improve the CBF estimation accuracy. Computer simulations were performed to compare the accuracy of CBF estimates derived from LAD, reformulated SVD (rSVD) and standard SVD (sSVD) techniques. Simulations were performed at image signal‐to‐noise ratios ranging from 20 to 400, cerebral blood volumes from 1% to 10%, and CBF from 2.5 mL/100 g/min to 176.5 mL/100 g/min to estimate the effect of these parameters on the accuracy of CBF estimation. The LAD method improved the CBF estimation accuracy by up to 32% in gray matter and 23% in white matter compared with rSVD and sSVD methods. LAD method also reduces the systematic bias of rSVD and sSVD methods to baseline SNR while producing more accurate and reproducible residue function calculation than either rSVD or sSVD method. Initial clinical implementation of the method on six representative clinical cases confirm the advantages of the LAD method over rSVD and sSVD methods. Magn Reson Med 61:418–428, 2009. © 2009 Wiley‐Liss, Inc.
Oral Healthcare Challenges for Older Punjabi-Speaking Immigrants*

RÉSUMÉ Cette étude a exploré comment les immigrants âgés d’origine sud-asiatique, parlant le pendjabi (quatre groupes de discussion; 33 participants) de Surrey en Colombie-Britannique, perçoivent leur santé buccale et les problèmes connexes. L’analyse a relevé deux thèmes généraux: les interprétations de la condition bucco-dentaire et les défis de santé bucco-dentaire. Le thème des interprétations avait quatre sous-thèmes: les dommages causés par le wai, les perturbations causé par la carie, l’adaptation aux prothèses dentaires, et qualité de vie; alors que le thème des défis considérés: remèdes à domicile, dentisterie occidentale; et difficultés d’accès aux dentistes. Les participants ont expliqué les maladies bucco-dentaires en termes d’une infection systémique (resha) et ont dit préféré les remèdes faits maison pour diminuer les écarts de chaleur (wai) dans la bouche. Nous concluons que les immigrants âgés d’origine sud-asiatique parlant le pendjabi interprète la santé et les maladies bucco-dentaires dans un contexte mixte de traditions occidentales et Ayurvédique, et gèrent leur santé buccale au moyen de remèdes traditionnels faits maison, complémentés au besoin par des soins d’urgence dispensés au Canada. ABSTRACT This study explored how older Punjabi-speaking South-Asian immigrants (four focus groups; 33 participants) in Surrey, British Columbia, perceive oral health and related problems. Content analysis revealed two umbrella themes: (a) interpretations of mouth conditions and (b) challenges to oral health. The umbrella themes had four sub-themes: damage caused by heat (wai), disturbances caused by caries, coping with dentures, and quality of life. Three challenges were considered: home remedies, Western dentistry, and difficulties accessing dentists. Participants explained oral diseases in terms of a systemic infection (resha), and preferred to decrease imbalances of wai in the mouth with home remedies from India. We conclude that older Punjabi-speaking immigrants interpret oral health and disease in the context of both Western and Ayurvedic traditions, and that they manage dental problems with a mix of traditional remedies supplemented, if possible, by elective oral health care in India, and by emergency dental care in Canada.
Fast functional brain imaging using constrained reconstruction based on regularization using arbitrary projections

This work describes a novel method for highly undersampled projection imaging using constrained reconstruction by Tikhonov‐Phillips regularization and its application for high temporal resolution functional MRI (fMRI) at a repetition time of 80 ms. The high‐resolution reference image used as in vivo coil sensitivity is acquired in a separate acquisition using otherwise identical parameters. Activation studies using a standard checkerboard activation paradigm demonstrate the inherent high sensitivity afforded by the possibility to separate activation‐related effects from “physiological noise. ”. In this first proof‐of‐principle of the constrained reconstruction based on regularization using arbitrary projections (COBRA) technique, experiments are performed in a single‐slice mode, which allows for a comparison with fast single‐slice echo‐planar imaging (EPI) at equal temporal resolution. The COBRA method can be extended to three‐dimensional (3D) encoding without severe penalty in temporal performance. Analysis of the global signal change demonstrates the excellent reproducibility of COBRA compared to standard EPI. Activation analysis is considerably improved by the possibility to remove electrocardiogram (ECG)‐related and breathing‐related signal fluctuations by physiological correction of each individual breathing and ECG cycle, respectively. Magn Reson Med, 2009. © 2009 Wiley‐Liss, Inc.
Social Isolation in Chinese Older Adults: Scoping Review for Age-Friendly Community Planning

RÉSUMÉ Les adultes chinois plus âgés peuvent être exposés à un risque accru d’isolement social et de solitude; pourtant, une telle compréhension des défis auxquels ils peuvent faire face pour la participation sociale dans leurs quartiers et communautés est fragmentée. Un examen de la portée a été entrepris pour décrire les connaissances actuelles sur l’isolement social et la solitude chez les aînés chinois vivant en milieu urbain dans les sociétés occidentales afin d’éclairer les recherches, les pratiques et les politiques futures au Canada. Dix-neuf articles répondent aux critères d’inclusion. Le système des communautés conçues pour les adultes vieillisantes de l’Organisation mondiale de la Santé a contextualisé les résultats de l’étude. Les études ont identifié des questions liées (1) à la participation sociale; (2) au soutien communautaire et aux services de santé; (3) au logement; (4) à la communauté et à l’information; (5) au respect et à l’inclusion sociale; (6) aux espaces extérieurs et aux édifices publics; (7) à la participation civique et à l’emploi; et (8) au transport. L’isolement social et la solitude sont des préoccupations croissantes au sein de cette population au Canada, et des recherches supplémentaires sont nécessaires pour en déterminer la portée et les interventions efficaces. ABSTRACT Chinese older adults may be at increased risk of social isolation and loneliness, and a fragmented understanding exists about the challenges they face for social participation in their neighbourhoods and communities. A scoping review was undertaken to describe the current knowledge on social isolation and loneliness in urban-dwelling Chinese older adults living in Western societies to inform future research, practice, and policy in Canada. Nineteen articles met the inclusion criteria. The World Health Organization’s age-friendly community framework contextualized the study findings. Studies identified issues related to (1) social participation; (2) community support and health services; (3) housing; (4) community and information; (5) respect and social inclusion; (6) outdoor spaces and public buildings; (7) civic participation and employment; and (8) transportation. Social isolation and loneliness is a growing concern in this population in Canada, and additional research is needed to identify its scope and effective interventions.