Camelus dromedarius) and Bactrian camels (Camelus bactrianus) back onstage and into the focus of animal breeders and scientists. In this review on the molecular genetics of these economically important species we give an overview about the evolutionary history, domestication and dispersal of Old World camels, whereas highlighting the need for conservation of wild two‐humped camels (Camelus ferus) as an evolutionarily unique and highly endangered species. We provide cutting‐edge information on the current molecular resources and on‐going sequencing projects. We cannot emphasise enough the importance of balancing the need for improving camel production traits with maintaining the genetic diversity in two domestic species with specific physiological adaptation to a desert environment.Old World camels have served humans in cross‐continental caravans, transporting people and goods, connecting different cultures and providing milk, meat, wool and draught since their domestication around 3000–6000 years ago. In a world of modern transport and fast connectivity, these beasts of burden seem to be out‐dated. However, a growing demand for sustainable milk and meat production, especially in countries affected by climate change and increasing desertification, brings dromedaries ( Camelus dromedarius) and two‐humped Bactrian camels (Camelus bactrianus) seem to be a perfect answer to these challenges as they are resilient to harsh climatic conditions and highly efficient in their production . Finally, the purpose and main types including interesting traits for performance and adaptation, will be discussed, as well as the currently available molecular resources to investigate these traits. We emphasise that it is important to keep a balance between conserving the genetic integrity, diversity and traditional management of the species, while responding to the constantly growing needs for intensification of breeding and selection using modern genomic tools.In this review, we aim to provide a comprehensive summary of the evolutionary history and domestication of Old World camels as well as their global dispersal. We will discuss the historic and ongoing hybridisation between Old World camels, which serves as improvement of production traits (milk and wool) in the domesticated dromedary and Bactrian camels, but threatens the genetic integrity of the last existing, highly endangered, wild two‐humped camels , suborder Tylopoda, and the family of Camelidae consisting of the tribes Camelini (Old World camels) and Lamini (New World camels), which diverged 16.3 (9.4–25.3) million years ago  Mya ; and HII, a centre of domestication was further to the east where people were familiar with wild camels over an extended period of time, e.g. in Kazakhstan or northwestern Mongolia. The lack of wild camel remains in the Neolithic strata of the Kopet Dagh foothills led to the assumption that fully domesticated two‐humped camels were acquired from eastern Asia  BCE , where their adoption into local economies may have been slow Bulliet . Anotheret al. et al. et al. Cross‐continental sharing of nuclear genotypes reflects an extensive gene flow between African and Asian dromedaries, notably with a panmictic population on a mitochondrial level  and dromedaries (C. dromedarius) was associated with the transportation of goods along multiple long‐distance trade routes. This practice intended to produce animals with the robustness of the Bactrian camel, the endurance of the dromedary and an ability to tolerate sharply contrasting climatic conditions. The history of anthropogenic hybridisation is currently being investigated using archaeozoological and palaeogenetic techniques (http://www.hybridcamels.com). Preliminary results revealed hybrids from a Roman archaeological site in Serbia, Viminacium, dated to approximately the late third to fourth centuries CE  hybrids] from Middle Eastern and Central Asian countries. This improvement in physical performance and other  traits, termed heterosis or hybrid vigour, arises from allelic interactions between parental genomes, potentially leading to increased growth, productivity and fitness of the fertile F1 hybrids. Hybrids of the second generation (F2), which are crosses between F1 hybrids (Jarbai), in Old World camels are usually not favoured because of their difficult character and weak progeny performance , has produced a camel characterised by its light skeleton, fine musculature, narrow abdomen (‘greyhound belly’) and a small hump. The global morphology of racing camel Fig. d is so shachi in Arabian countries) are slaughtered for meat, whereas in other regions adults are preferred  were identified in the αs1‐CNs , consisting of et al. et al. et al. Meat performances and composition according to camel type were investigated in four Saudi Arabian dromedary populations using carcass traits, and physical, chemical and organoleptic meat traits   World camelids are considered unique among mammals because of several peculiarities in their adaptive immune response. In addition to conventional antibodies, i.e. IgGs that usually consist of two identical heavy (H) and two light (L) chains, camelids have functional homodimeric IgGs composed of only two identical H‐chains, but missing the L‐chains. The antigen‐binding region of the so‐called Nanobodyδ and γ genes increase the diversity repertoire of T‐cells in dromedaries. They have not been identified in mammalian species so far and could enhance the acquirement of new antigenic specificity , assembled using Illumina short paired‐end and <20 K insert mate‐pair reads on different scaffold levels. The first genome was published for C. ferus in 2012  produced a set of 23 602 putative gene sequences out of which over 4500 were potentially novel or fast evolving gene sequences ’ and ‘CAMELMILK’, as well as a new International Committee for Animal Recording initiative (ICAR), aim to establish the et al. In the medium term, the availability of a camel SNP genotyping platform may boost national governments’ investments in national breeding programmes based on systematic phenotype and genealogical recording. Such data will form the basis for improved breeding practices and breed management, and for future estimation of genomic breeding values and genomic selection (e.g. Hayes In the long term, the challenge remains to harmonise and standardise the collection of phenomic and genomic data und to utilise them in a way that is beneficial for human and animal needs. This includes not only the improvement of desirable production traits but also the conservation of genomic diversity and of the evolutionarily significant physiological adaptations in camels.


Memory function was assessed in 1999 and 2009 using the paired associates learning test (PAL), while naevus count and leucocyte telomere length  were measured once. Higher baseline naevus count was significantly associated with fewer errors at the baseline and follow‐up PAL, as well as with change in PAL score over 10 years. This association was significantly attenuated after adjustment for LTL. The significant association between naevus count and PAL score was reproduced in the replication sample. These findings suggest that melanocytes might be used as model system to study the biological ageing pathways involved in neurodegeneration.The presence of a skin–brain connection whereby alterations in the skin can inform on mechanisms underlying neurodegenerative diseases is increasingly recognized. In this study, we used a discovery ( The limited availability of suitable neuronal models to study the biological alterations underlying neurodegenerative diseases has precluded identification of potential therapeutic targets. Our results suggest that melanocytes and neurons might preserve common biological regulations in postnatal life and support the use of readily available melanocytes from the skin to shed light on the complex biology underlying neurodegenerative diseases.1The presence of a skin–brain connection, so that alterations detected on the skin might inform on specific neurogenerative processes underlying Parkinson's disease and Alzheimer's disease (AD), is attracting increasing interest . The first (discovery) sample included 321 participants with measures of episodic memory function available in 1999 and 2009, and whole body naevus count assessed at baseline Table , 1998. Tα = 0.05.In the discovery sample, change in PAL score for the periods 1999‐2009 conditional on earlier PAL score was calculated by regressing the PAL follow‐up score on the earlier PAL measure, saving and standardizing the residuals. Subsequently, we implemented a series of generalized estimating equations (GEE) to fit population‐averaged panel‐data  models with unstructured within‐group correlation for the association of (a) baseline naevus count with memory function both at baseline and follow‐up, (b) baseline naevus count and changes in episodic memory, (c) LTL and naevus count at baseline and d) LTL and episodic memory. Normal distribution of the dependent continuous variables was graphically inspected with histograms and distributional plots . Variables that deviated from normality were transformed with the natural logarithm before entering the GEE analysis. Results from the GEE analysis are presented as coefficients (β) and 95% confidence intervals (CI). To explore the proportion of the association between baseline naevus count and change in PAL explained by chronological or biological age, we included age and LTL, separately and in combination, in the models exploring the relationship between baseline naevus count and PAL residuals. The GEE analysis for the association between naevus count and PAL score was repeated in the replication sample. The Stata 13 statistical package was used for all analyses. We deemed statistical significance at β = −0.209; 95% CI ‐0.384, ‐0.034; p = 0.019) and follow‐up  assessments. Naevus count was also related with LTL, so that people with higher naevus count had longer LTL . In turn, LTL was associated with the performance at the PAL test . All these associations remained significant after adjustment for chronological age. People with higher naevus count at baseline had a lower memory decline during follow‐up  , further adjustment for LTL substantially reduced the strength of the association between naevus count and change in PAL  , while chronological age was not .Participants with higher naevus count had a better episodic memory (making fewer errors at the PAL) both at the baseline . Similar to the results obtained in the discovery sample, this association was unaffected by adjustment for age  (Table Following the same statistical approach, but with PAL results log transformed as non‐normally distributed, the association between naevus count and PAL score was confirmed using the cross‐sectional data available in the replication sample (These results show, for the first time, an association between cross‐sectional measures of naevus count and episodic memory, as well as that baseline naevus count can predict decline in episodic memory over 10‐year follow‐up. They also document that these associations are likely to be mediated by pathways regulating biological ageing. Our data support the hypothesis that shared biological ageing pathways influence the process of neurodegeneration associated with decline in episodic memory as well as melanocyte regenerative capacities.Decline in episodic memory is commonly observed after 30–35 years of age, and its rapid impairment has been linked not only with the risk of AD but also with other neuropsychiatric disorders characterized by reduction in hippocampal volume (Dickerson & Eichenbaum, Our study has several strengths. The availability of robust memory measures assessed at two different time points 10 years apart reduces the risk of learning effects, often complicating the interpretation of changes in cognitive function observed in longitudinal studies. Previous reports have validated the PAL tests for the assessment of episodic memory deficits, showing its ability to detect early memory changes predictive of AD risk. LTL was measured using terminal restriction fragment, which is currently considered the gold standard method for LTL assay. Finally, the work previously published by our group on the relationship of LTL with episodic memory as well as with naevus count increases the robustness of our results. Among limitations, while the association between naevus count and memory function was replicated in two independent samples, the size of both samples was relatively small. Also, while several reports have now demonstrated that telomere length is highly synchronized between different cells and tissues at any age (Butler et al., In conclusion, the inverse association between naevus count and risk of episodic memory decline observed in our study suggests that a faster age‐related decline in naevus count might help identification of people with faster evolution of biological ageing, and thus at greater risk of neuropsychiatric disorders. Also, our findings suggest that peripheral melanocytes could maintain common biological regulation with neurons in postnatal life, at least for pathways influencing the progression of biological ageing. Consequently, clarification of the mechanisms involved in the control of biological ageing of peripheral melanocytes might provide valuable information on the potential pathways involved in neurodegeneration and leading to memory decline.


Iron–sulfur cluster biogenesis is a complex process mediated by numerous proteins among which two from bacteria chaperones, called HscB and HscA in bacteria. They are highly conserved up to eukaryotes and homologous to DnaJ and DnaK, respectively, but with specific differences. As compared with other chaperones, HscB and HscA have escaped attention and relatively little is known about their functions. After briefly introducing the various chaperone families, we reviewed here the current structural and functional knowledge HscA and HscB and on their role in cluster formation. We critically evaluated the literature and highlighted the weak aspects which will require more attention in the future. We sincerely hope that this study will inspire new interest on this important and interesting system. AD, Alzheimer diseaseALS, amyotrophic lateral sclerosisFeS, iron sulfurHSP, heat shock proteinsISC, iron–sulfur cluster, PDPD, Parkinson's diseasepolyQ, polyglutaminein vivo is thus not always spontaneous and the various organisms have evolved a family of highly conserved proteins called molecular chaperones that have essential roles in many cellular processes, including protein folding, targeting, transport, degradation and signal transduction The amino acid sequence of a protein is thought to contain all the information required to determine a functional structure in a given environment In recent years, molecular chaperones have assumed an increasing importance for health in view of the several neurodegenerative disorders characterized by conformational changes in proteins that experience misfolding, aggregation and intra‐ or extraneuronal accumulation as amyloid fibrils. Examples of misfolding diseases are Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and related polyglutamine (polyQ) expansion diseases. Although the protein culprits that aggregate in these disorders are unrelated in size, function, and primary sequence, the resulting aggregates typically contain fibrillar, amyloid‐like structures which are detergent insoluble and protease resistant, with a high β‐sheet content and a cross‐β structure The scope of this mini‐review is to summarize the information available on molecular chaperones with specific attention for those involved in iron–sulfur (FeS) cluster biogenesis, an essential pathway which is still relatively underexplored Temperature increase activates the cellular heat shock response with consequent increase in heat shock protein (Hsp) production. Hsps act as chaperones and are essential for the recovery from stress‐induced damage et al. Hsp70 chaperones are activated by stress response and are involved in folding newly synthesized and misfolded proteins, preventing protein aggregation and cellular trafficking. They also help translocation of proteins across membranes as well as assembly/disassembly of oligomeric structures In prokaryotes, another Hsp70 homolog was identified in addition to the stress‐related Hsp70 DnaK and called HscA. isc operon is one of the three machines responsible for FeS cluster biogenesis in bacteria. It presents a high level of conservation with the homologous eukaryotic system isc components are the desulfurase IscS, the scaffold protein IscU on which the FeS cluster is assembled, an alternative scaffold IscA, the two chaperones HscA and HscB, the transcriptor regulator IscR, ferredoxin (Fdx), and the modulator IscX. The names of these proteins are confusing because they can change completely in the close eukaryotic orthologs.Dysfunctions in FeS protein biogenesis and mitochondrial iron accumulation in heart and neurons are part of the phenotype of a genetic neurodegenerative disease called Friedreich's ataxia. This pathology is caused by the deficiency of a mitochondrial protein, frataxin, highly conserved throughout species In vitro studies have suggested that the two chaperones may assist FeS cluster formation by maintaining the scaffold protein in a conformation suitable for cluster assembly through interacting with the loaded scaffold protein IscU. Alternatively, it was suggested that HscA may facilitate cluster transfer from cluster‐loaded (holo)‐IscU to other acceptor cluster‐free (apo‐) proteins FeS cluster biosynthesis can be simplified in two steps: first the FeS cluster is assembled on IscU and is then transferred to the target apo‐proteins 98ELPPVKIHC106) is available  but HscB was found to stimulate this activity up to 3.8‐fold. To better understand the mechanism and regulation of HscA, Silberg and Vickery investigated the kinetics of ATP hydrolysis and proposed a model for the ATPase reaction cycle The mechanisms involved in IscU binding and release are not well understood. HscA exhibits a low intrinsic ATPase activity  and a partially disordered one (D). If this were true, cluster formation could stabilize the S‐state, which could have a lower affinity for IscS and detach from it T. maritima chaperone DnaK‐DnaJ demonstrated an inhibitory effect on the rate of FeS cluster transfer from IscU et al. observed that the HscA‐HscB complex from A. vinelandii facilitates FeS cluster transfer in vitro from the holo‐IscU scaffold protein to apo‐Fdx and that cluster transfer is an ATP‐dependent process E. coli showed that the HscA‐HscB‐ATP complex, as well as isolated HscB, have an inhibitory effect when the cluster is formed on IscU and independently from the source of sulfur . In addition, in the presence of only HscB, the cluster assembled on IscU is transferred to apo‐Fdx at a slower rate than in the absence of HscB unless ATP and HscA are also present Several studies have been performed investigating the effects of the HscA/HscB chaperones on specific steps of the FeS cluster biosynthesis leading to controversial results. Kinetic studies of FeS cluster transfer from holo‐IscU to apo‐Fdx in the presence of in vivo existence of a D state of IscU is far from having been demonstrated. IscU is certainly a marginally unstable protein Despite considerable progresses in understanding the function of the two chaperones HscA and HscB (and their homologs in eukaryotes) in FeS cluster biogenesis, several aspects remain to be clarified. First of all, it remains an open question why chaperones are needed given that the scaffold protein readily transfers the cluster to other acceptors without the need of any assistance


Although linear mucosal tears have been reported, we found a relatively rare case of wavy mucosal tear in collagenous colitis. This may be related to the mutual weak adhesiveness between the epithelium and collagen band. This complication necessitates great care to be taken while performing colonoscopy in patients suspected of collagenous colitis. Physical examination and stool and blood test results were unremarkable. She had hypertension and osteoarthritis. Nonsteroidal anti‐inflammatory drugs and a proton‐pump inhibitor (lansoprazole) had been prescribed after surgery for osteoarthritis performed 4 months ago. During removal of the colonoscope, we found a 5‐cm‐long wavy mucosal tear in the sigmoid colon Figure . What is2Collagenous colitis was diagnosed based on hematoxylin‐eosin stain Figure  and AzanLinear mucosal tears in collagenous colitis patients have been reported.The authors declare that they have no current financial arrangement or affiliation with any organization that may have a direct influence on their work. Informed consent was obtained from the patient for the publication of their information and imaging.All the authors made substantial contribution to the preparation of this manuscript and approved the final version for submission. KT and JY: drafted the manuscript. KH and AT: provided clinical support. ST: reviewed the manuscript carefully.


BC), Canada; and (2) to characterize factors associated with screening among screening‐age recent immigrant women in BC. We examined 2 population‐based cohorts of women eligible for breast screening participation (537 783 women) and retention (281 052 women) using linked health and immigration data. Breast screening rates were presented according to socio‐demographic and health‐related variables stratified by birth country. Factors associated with screening among recent immigrant women were explored using Poisson regression. We observed marked variation in screening participation across birth country cohorts. Eastern European/Central Asian women showed low participation (37.9%) with rates from individual countries ranging from 35.0% to 49.0%. Participation rates for immigrant women from the most common birth countries, such as China/Macau/Hong Kong/Taiwan (45.7%), India (44.5%), the Philippines (45.9%), and South Korea (39.0%), were lower than the nonimmigrant rates (51.2%). Retention rates showed less variation by birth country; however, some disparities between immigrant and nonimmigrant groups persisted. Associations between screening indicators and study factors varied considerably across immigrant groups. Primary care physician visits were consistently positively associated with screening participation; this variable was also the only predictor associated with screening within each of the groups of recent immigrants. Our study provides unique data on both screening participation and retention among Canadian immigrant women compiled by individual country of birth. Our results are further demonstration that screening disparities exist among immigrant populations as well as in comparison with nonimmigrant women.Breast cancer screening programs operate across Canada providing mammography to women in target age groups with the goal of reducing breast cancer mortality through early detection of tumors. Disparities in breast screening participation among socio‐demographic groups, including immigrants, have been reported in Canada. Our objectives were to: (1) assess breast screening participation and retention among immigrant and nonimmigrant women in British Columbia ( Screening mammograms are publicly funded in all Canadian provinces for women in target age groups yet in most Canadian jurisdictions participation rates remain well below the national target level of 70%.Disappointing breast screening participation rates as well as a desire to assess potential health inequities in cancer screening have motivated several recent investigations into potential screening disparities among socio‐demographic groups in Canada.The world region categorization used in prior Canadian studiesBritish Columbia has several strengths as a population within which to examine cancer screening patterns among Canadian immigrants. First, the 2016 Canadian Census showed that more than 1.29 million individuals, or 28.3% of the province's population, are foreign‐born.The objectives of our study were: (1) to assess both screening participation and retention rates among BC's most common immigrant sub‐populations defined by country of birth; (2) to compare screening rates in these populations to those of nonimmigrant women; (3) to assess how breast screening rates vary with socio‐demographic and health‐related variables within these populations; and (4) to offer a specific focus on screening‐eligible recent immigrant (<10 years in Canada) women in terms of personal and health‐related characteristics and the associations between these factors and breast screening.22.1This study utilized several population‐based administrative databases from health and other government agencies via a comprehensive research data application facilitated through Population Data BC. Approval from all data stewards was obtained prior to data access. Specific details regarding the data sources accessed are provided in Table British Columbia, Canada has a universal, publicly funded healthcare system that fully funds breast cancer screening mammograms through a provincial screening program. Current provincial guidelines recommend that average risk women age 50‐74 receive a mammogram every 2 years.Research ethics approval was obtained from the University of British Columbia—BC Cancer Agency Research Ethics Board. The identities of all individuals in study data sets were replaced with study‐specific random numbers that permitted linkage across the various data sources while protecting confidentiality of all individuals.2.22.2.1The study cohort to examine screening participation was identified from the provincial health registration file and consisted of all women in BC who were aged 50‐69 years for the entire period from 1 January 2013 to 31 December 2014. This age group was chosen to align both with prior studies of breast screening participation and to reflect an age group within which average risk women have generally been recommended to screen biennially in Canada. Women were excluded if they had a diagnosis of breast cancer or mastectomy prior to 1 January 2013 were not continuously registered in the provincial health insurance plan 1 from January 2011 through the study period, or died prior to 31 December 2014. Women had to be registered over this entire period in order to characterize health‐service use and other health measures over a 2‐year look‐back period (2011‐2012) prior to the interval over which we calculated our study outcome (2013‐2014).2.2.2For the retention rate outcome, we examined a cohort of all screening eligible women who received a screening mammogram (the “index” screen) through the provincial screening mammography program of BC (SMPBC) between 1 January 2010 and 30 June 2012. These dates were chosen to permit a minimum of 30 months of follow‐up on each cohort member in order to determine a 30‐month retention rate. A 30‐month retention rate endpoint was chosen to align with the definition reported as a performance indicator by breast screening programs in Canada.2.3The primary study endpoints were the screening participation rate and 30‐month screening retention rate. The participation rate was defined as the number of women having a screening mammogram performed through the SMPBC between 1 January 2013 and 31 December 2014 out of the number of eligible women in the cohort. The retention rate was calculated as the number of women who had a screening mammogram performed through the SMPBC within 30 months of their index mammogram out of the total number of women who were eligible to be re‐screened over that period . Diagnostic mammograms are not performed through the SMPBC in BC and are billed directly to the provincial health system by radiologists and can be booked only with a referral from a physician. However, it is unknown the extent to which women utilize diagnostic mammograms in the province for screening purposes. Thus, as a sensitivity analysis of the participation rate, we further included any bilateral mammograms billed directly to the health system (henceforth termed “diagnostic” mammograms) in the study period for any women who did not have a screening mammogram performed within the SMPBC.We created study groups of nonimmigrant and immigrant women through linkage of the study cohorts to the immigration data. Any cohort member that did not link to the immigration data was assumed to be a nonimmigrant woman. Available immigration data included only individuals who immigrated to Canada between 1985 and 2012 and thus women who immigrated prior to 1985 cannot be distinguished in our data from nonimmigrant women. Our main analyses aimed to present screening rates by birth country as identified in the immigration file. Geopolitical changes that have taken place over the immigration dates covered by this data file necessitated combining some countries into single groups: countries of the former Union of Socialist Soviet Republics (USSR) were assembled into a “Former USSR State” group; countries of the former Yugoslavia were aggregated into “Former Yugoslavia”; women from the People's Republic of China, Macau, Hong Kong, and Taiwan were combined into a single group labeled “CMHT” in all tables and figures. We created world regions based primarily on groupings of countries used by the World BankSeveral socio‐demographic and health‐related measures were generated from the data sources identified in Table 2.4Age‐standardized participation and retention rates were calculated according to country and world region of birth using the age‐distribution of the nonimmigrant women as the standard population. Rates were generated for all countries with a minimum of 100 eligible women and presented graphically with 95% confidence intervals.For birth countries for which there were at least 2000 women in the participation cohort, we undertook further analyses examining both the characteristics of the cohorts and their screening endpoints. This minimum sample size was chosen in order to obtain reasonable confidence interval widths for participation rates. Socio‐demographic and health measures were compared across immigrant groups and nonimmigrant populations using descriptive statistics. Screening participation and retention rates were generated by study group, both overall and stratified by other key variables, to explore the variation in screening endpoints; exact 95% confidence intervals were calculated for both endpoints.We further examined the characteristics of screening eligible immigrants who had resided in Canada for <10 years (“recent” immigrants). Descriptive statistics for socio‐demographic, healthcare and immigration factors were generated by country of birth for women from the 8 most common birth countries. These countries were chosen as they accounted for more than 80% of the recent immigrant population, and each had a sufficient sample size to calculate participation rates. Recent immigrant women from countries other than these 8 were pooled into an “Other Immigrant” category for this analysis. We calculated participation rates according to these same variables within each birth country cohort. To identify independent predictors of screening for each birth country cohort, we used Poisson regression models with adjustment to the parameter estimate variances to permit a direct estimation of the adjusted relative risks as the endpoint of interest (screening participation) was not rare.http://www.cran.r-project.org/).All analyses were conducted using the Statistical Analysis Software (SAS) version 9.4  and the R statistical computing software version 3.3.2 (33.1The participation cohort included 537 783 women of whom 85 902 (16.0%) were identified as immigrants. The majority of the immigrant population who were eligible for breast screening during our study period hailed from Asia with more than 59.0% of the immigrant population in our cohort born in CMHT, the Philippines or India . The overall participation rate for the cohort increased to 54.2% with the ordering of the various subpopulations remaining largely the same. Although the inclusion of these mammograms increased some groups’ participation rates approximately in‐line with the increase seen in the overall population rate (4%), the Iranian women's rate increased 8% with these additional mammograms. In contrast, the rate for Indian women increased only 1.8%. Generally, relationships between participation and other variables remained similar to the main analysis.3.2The retention rate cohort included 281 052 women of which 12.8% were identified as immigrants . Retention rates across immigrant groups ranged from 64.9% in Korean women to 77.4% for women from the United Kingdom ; however, in other groups, there appeared to be little relationship. There was a considerable range in Canadian language fluency with women from CMHT and India having >75% with no competence in English or French, while others reported near 100% fluency. Language competence did not seem to associate with screening participation in several of the immigrant groups  while women from the India, Former USSR, and Other Immigrant groups showed lower screening participation among women with no Canadian language competency. Education level at the time of landing similarly showed strong variation across study groups. Chinese immigrants reported 50.3% having secondary school education or less; nearly half of recent Indian immigrants reported no formal education and an additional 34.8% reported secondary school or less. For immigrant women from the Philippines, US, and the Former USSR, the percentage of women with undergraduate or graduate degrees was above 60% suggesting highly educated groups. Curiously, 11.2% of recent immigrants from the UK reported no formal education which may represent a data quality issue; the majority of these women were identified as dependent immigrants within the immigration data. Indian immigrants and Other Immigrants also showed a comparatively higher percentage of women with no prior education. There was a strong association in these 2 groups between reporting no prior education and older age, no Canadian language proficiency, and immigrating as a family class or refugee immigrant (data not shown). The relationship between education level and screening participation was not uniform across immigrant groups.Screening participation rates were higher among refugee immigrants compared to either economic or family class immigrants for immigrants from CMHT, India, and South Korea. In all 3 of these groups, however, the number of women immigrating under this class represented a very small proportion of the immigrant population. Among immigrants from the Former USSR, refugee class immigrants showed the lowest participation rates; however, this group was comprised of only 22 women, and thus, the participation rate is highly imprecise.The median number of PCP visits was lower for women from South Korea (5.0) and CMHT (6.0) and much higher for women from India (13.0) and Iran (11.0). The percentage of South Korean (21.0%) and CMHT (15.3%) recent immigrants that had no PCP visits in the 2‐year look‐back period was higher than in the other groups. As with the analysis on the entire cohort, the recent immigrant analysis revealed a strong positive relationship between screening participation and number of PCP visits. In all immigrant groups, the women with no recent PCP visits had the lowest screening rates.Our analysis to identify independent predictors of breast screening participation among the most recent immigrants identified only the number of PCP visits as a significant predictor within all immigrant groups. Compared to women who had 10 or more PCP visits, those with no recent PCP visits showed adjusted relative risks (ARRs) in the range from 0.11 to 0.37 Table  indicati4Our study demonstrates that screening mammography participation rates in BC are lower for some immigrant subpopulations compared to nonimmigrant women. We identified variation in participation rates when women are grouped by both world region of birth and by individual countries of birth. Participation rates also varied within immigrant subpopulations according to age group, duration of residence in Canada, as well as other socio‐demographic variables. At the same time, the relationship between participation and these variables was not consistent across the immigrant populations.To our knowledge, this is the first large population‐based study in Canada that has examined breast screening retention rates as an endpoint in comparing immigrant and nonimmigrant groups. In comparison with the participation rate analysis, we found less variation in screening retention rates across both world region and birth country groups. When the analysis was restricted to women with at least one mammogram within the program prior to the index screen, the variability in retention rates was reduced further Table . Our retOur participation results are consistent with prior Canadian studies that have reported lower breast cancer screening rates among immigrant women and specific immigrant subpopulations.Our analysis at the individual country level identified some screening patterns not reported in recent studies which examined data at the world region level. Screening participation and retention among South Korean immigrant women in our study was very low relative to nonimmigrants and other immigrant populations; among recent immigrants, this group also demonstrated some of the lowest participation and retention rates. Our findings also suggested that a significant proportion of this group had no apparent PCP visits in the look‐back period  and low proficiency in Canadian languages. As noted in a recent review article,There have been numerous studies of breast cancer screening among immigrant populations undertaken in other countries.Our results provide further evidence of the strong association between screening participation and primary care physician (PCP) contact. Participation rates within each of our study groups generally increased with physician contact; the lowest rates were observed in the groups of patients that reported no PCP visits. Further, in our analysis of predictors of screening participation among recent immigrants, the number of PCP visits was the only variable associated with having been screened in all immigrant groups examined. For recent South Korean immigrant women with no PCP visits , the participation rate was only 5.2% while for women with 10 or more PCP visits it was 46.1%.The results were nearly identical for recent Chinese immigrant women and similar for other immigrant groups. Generally, retention rates were higher for groups with more PCP contact; it is worth noting that <2% of each study group in the retention rate analysis had no PCP visits and thus their retention rates are highly imprecise. Despite using a number of definitions for PCP contact, the association with breast screening has been reported in a number of Canadian studies.In Ontario, there has been considerable work examining the specific patient enrollment model (PEM) that attaches patients to a PCP and how this correlates with breast screening.Our study strengths include the use of population‐based, administrative data sets which permit the estimation of population screening rates and reduce the potential for selection bias. Thus, in contrast to studies that utilize survey methods, the present study is not affected by survey response bias or recall bias associated with the timing of the most recent mammogram reported by respondents. The data sets included information from diverse sources permitting the examination of screening rates by a variety of socio‐demographic and health variables. The immigration data included the specific country of birth of each immigrant woman in our cohort permitting us to examine screening indicators by country of birth rather than aggregate world regions alone.Reliance on administrative data does, however, impose some limitations on our findings. Although our study aimed to compare screening participation and retention rates in immigrant and nonimmigrant women, women who immigrated to Canada prior to 1985 are included in the nonimmigrant group. Although the magnitude of this misclassification is not known, because long‐term immigrants tend to exhibit similar screening rates to nonimmigrants, our reported rates among immigrants are almost certainly lower than they would be had we been able to identify immigrants that landed in Canada prior to 1985 and include them in the immigrant group. The linkage of the immigration database to the provincial health client file to identify immigrants within the BC health system database was not performed directly by the research team and thus we could not directly assess the quality of the linked cases. The group responsible for the linkage, however, has significant expertise in record linkage and maintains the linked database infrastructure for a provincial, health data linkage research platform. We were also unable to examine immigrant women's screening, surgical and breast cancer histories prior to when they were represented in provincial data sets. Thus, women who developed breast cancer or had mastectomy surgeries outside of BC could not be removed from the screening‐eligible cohort. The unexpectedly high percentage of immigrants from the UK reporting no prior formal education may suggest that education status was not accurately captured for all women within the immigration data. As the majority of these women were identified as dependents  in the immigration data, it is possible that this information is less relevant for this type of applicant and was not captured as accurately. Unfortunately, we were unable to conduct verifications of the data due to the administrative nature of its collection and thus this remains a limitation of our data. It is possible that the imperfect measurement of this variable could impact the model selection and our ability to detect education effects or the effects of other variables considered in the models; however, we cannot fully quantify the potential impact of this.We were also limited in our ability to count primary care visits definitively for each cohort member. Although primary care in BC is mainly delivered by fee‐for‐service physicians, a smaller fraction of physicians are paid under an alternate payment program for which no service use data are available. The implication is some patients who appeared to have no primary care encounters may in fact have seen a physician paid through alternative payments. Only 5.9% of the total cohort had no physician visits within our look‐back period and thus the affected group did not comprise a significant portion of the total cohort. We relied on an ecological variable for socioeconomic status (income quintile) based on the cohort member's postal code of residence which may not accurately reflect their true income or socioeconomic status. The area‐based income quintile available within our data sets was also derived using information collected from the 2006 Canadian census. It is possible that some neighborhood incomes have changed between 2006 and our follow‐up periods and thus are not accurately captured within our data sets. Finally, screening rates for many of the birth country groups examined had low statistical precision due to the small numbers of women representing these groups within the study cohort.Despite our findings of lower screening rates among some immigrant populations in BC, it is important to also reflect on the population statistics that our study presented, principally that only 50% of the eligible women participated in breast screening over the 2‐year follow‐up. Further, the 30‐month retention rate for first time attendees in the present study was 44%. These statistics are far below targets set by Canadian cancer screening expert advisory panels.Addressing the observed screening disparities will be a complex task given the diversity of the BC immigrant population. The present paper was not intended as a comprehensive review of potential interventions to address disparities in breast screening; however, the literature related to screening barriers and interventions among immigrants is rich. Our findings highlight that screening rates are generally lowest among new or most recent immigrants suggesting this population as an important focus for intervention. However, designing interventions will be challenging given that, as shown in our findings, recent immigrants to BC are diverse with respect to characteristics such as language, PCP contact, age, and education level. This variation exists even within groups of women that immigrate from a common world region . Despite this, as a substantial proportion of un‐screened recent immigrants have had PCP contact, interventions mediated through PCPs may be an approach to reach many women. In Canada, recently published studies on interventions to improve screening rates mediated through PCP's reported positive results.None declared. Click here for additional data file.


HIV may reduce the stigma attached to HIV and ensure maximal uptake of HIV prevention initiatives. The extent to which levels of HIV knowledge in the general population of sub‐Saharan Africa have changed in the current era of antiretroviral therapy (ART) scale‐up remains unknown.Population‐level improvements in knowledge about HIV knowledge in the general population were drawn from the 2003 to 2015 Demographic and Health Surveys (DHS) and AIDS Indicator Surveys (AIS) of 33 countries in sub‐Saharan Africa. The DHS/AIS contain five questions on HIV prevention and transmission that have been used by the Joint United Nations Programme on HIV/AIDS (UNAIDS) as a core indicator of HIV knowledge. We created a composite HIV knowledge variable equal to the number of correct responses to these five questions; a participant was considered to have comprehensive knowledge of HIV (yes/no) if he/she answered all five questions correctly. We fitted negative binomial regression models with cluster‐correlated robust standard errors and country fixed effects, adjusted for socio‐demographic variables, specifying HIV knowledge as the dependent variable and year as the explanatory variable. As an alternative parameterization, we also fitted a multivariable linear probability model with cluster‐correlated robust standard errors and country fixed effects specifying comprehensive knowledge of HIV as the dependent variable.Data on DHS/AIS were included in the analyses. The mean HIV knowledge score was 3.7 among women and 3.9 among men (p < 0.001). Only 35% of women and 41% of men (p < 0.001) had a comprehensive knowledge of HIV. We estimated a modest but statistically significant positive association between year of DHS/AIS and HIV knowledge , 0.001 to 0.009). Similarly, we estimated a statistically significant positive association between year of DHS/AIS and comprehensive knowledge of HIV , suggesting an approximately 1% relative increase per year in the percentage of the general population who possess a comprehensive knowledge of HIV.A total of 791,186 women and 395,891 men participating in 75 HIV knowledge across sub‐Saharan Africa.There have been minimal improvements over time in  Although there is optimism that an “AIDS‐free generation” is within reach The state of knowledge about HIV within the general population may be an important factor influencing the success of global initiatives in reducing HIV incidence and encouraging the early diagnosis and linkage of PLHIV to care. In sub‐Saharan Africa, one of the cornerstones of HIV prevention efforts has been the provision of information on HIV transmission to enable individuals to identify and avoid engaging in behaviours that increase HIV transmission risk. For example, in a South African cohort, the propensity of young women to misidentify themselves as being at no or low risk for HIV acquisition appeared to be related to an incomplete consideration of sexual risk factors In addition to facilitating behaviour modification, enhancing individuals’ perceptions of their risk may encourage the uptake of HIV counselling and testing (HCT)  Improved knowledge about HIV may also encourage testing and treatment by reducing HIV‐related stigma. Lack of understanding about how HIV is acquired, transmitted or treated reinforces instrumental stigma in the general population in both high‐ and low‐income settings In 2001, the United Nations General Assembly Special Session on HIV/AIDS (UNGASS) included HIV knowledge among people ages 15 to 24 as one of its core indicators for tracking national HIV programmes In 2001, UNGASS set an ambitious target: by 2010, 95% of people aged 15 to 24 years worldwide would have a comprehensive knowledge of HIV/AIDS, defined as a correct answer to all five core indicator questions. Unfortunately, no sub‐Saharan African countries were able to meet that target, with the Joint United Nations Programme on HIV/AIDS (UNAIDS) reporting a range of 2% to 77% among people aged 15 to 24 years in countries surveyed between 2005 and 2009 As these surveys were conducted, ART has been widely distributed throughout sub‐Saharan Africa. As ART scale‐up has typically been accompanied by community sensitization and HIV knowledge campaigns, it is possible that knowledge about HIV at the population level has concomitantly improved. However, the extent to which levels of HIV knowledge in sub‐Saharan Africa have changed in the current era of ART scale‐up is largely unknown, as there have been few analyses of HIV knowledge trends in general population samples, nor have there been any cross‐national studies. To help fill this gap in the literature, we analysed cross‐sectional, individual‐level data pooled from the DHS and AIS in order to describe recent trends in knowledge about HIV in sub‐Saharan Africa.2The DHS and AIS are nationally representative, population‐based surveys conducted approximately every five years in over 90 low‐ and middle‐income countries We focused our analysis on countries in sub‐Saharan Africa during the period 2003 to 2015, as this was a period of significant ART scale‐up throughout the subcontinent promoted by the Global Fund for AIDS, Tuberculosis and Malaria and the US President's Plan for AIDS Relief 2.1HIV knowledge score, which we calculated as the number of correct responses to the five questions on HIV prevention and transmission used by UNAIDS as a core indicator . The mean HIV knowledge score was 3.8 (SD 1.2) both among people at least 25 years of age and people younger than 25 years of age. The question most frequently answered incorrectly (37%) was “Can a person get HIV from mosquito bites?” Only 35% of women and 41% of men (p < 0.001) had a comprehensive knowledge of HIV. The percentage of people with a comprehensive knowledge of HIV was 37% both among people at least 25 years of age and people younger than 25 years of age. Trends in HIV knowledge by year are shown in Figure Of the 1,286,961 individuals included in the 75 DHS/AIS, we excluded 99,894 with missing data for any of the five HIV knowledge items, resulting in 791,186 women and 395,891 men who were included in the analyses. Survey refusal rates in the DHS/AIS were typically less than 10%, and no survey had a refusal rate more than 20%. Respondent characteristics and the percentage correctly answering each HIV knowledge question are stratified by gender in Table b = 0.005; 95% confidence interval (CI), 0.001 to 0.009). Results were similar between people at least 25 years of age  and people younger than 25 years of age . Similarly, we estimated a statistically significant positive association between year of DHS/AIS and comprehensive knowledge of HIV . Put another way, each additional year of DHS/AIS was associated with an approximately 1% relative increase in the percentage of the general population who possess a comprehensive knowledge of HIV. Results were similar between people at least 25 years of age  and people younger than 25 years of age .In a multivariable regression model fitted to the pooled data, we estimated a modest but statistically significant positive association between year of DHS/AIS and HIV knowledge  hold a comprehensive knowledge of HIV prevention and transmission, far short of the 95% goal set by UNGASS in 2001. Even the country with the highest rate of comprehensive HIV knowledge, Rwanda, failed to achieve more than 70% in its most recent survey. If current trends persist in a linear fashion, it will be decades before any country in sub‐Saharan Africa approaches the UNGASS 95% goal.Our findings suggest that decades of efforts at the national and international levels have been largely ineffectual in improving HIV knowledge. It is possible that resources devoted to improving HIV knowledge are being wasted and could be marshalled elsewhere in the HIV prevention and treatment response. Alternatively, we may need to redouble these efforts to further their reach—or better yet, develop and implement innovative and more effective HIV knowledge interventions. Such interventions could justifiably focus on women, given that women's levels of HIV knowledge were lower than men's in nearly all of the countries under study. Although there is evidence in support of interventions such as peer educational initiatives Further investments in interventions to improve HIV knowledge may be necessary to ensure the success of an increasingly sophisticated and diverse array of biomedical and behavioural approaches to HIV prevention. DHS/AIS data from the general population of sub‐Saharan Africa suggest mixed trends in the prevalence of risky sexual behaviours since 1999, with a decline in the prevalence of self‐reported unprotected sex but an increase in the prevalence of self‐reported multiple partners Moreover, we found that nearly a quarter of respondents thought that HIV could be transmitted through sharing food, a belief that contributes to the stigmatization of PLHIV There are several limitations to our study. First, our study did not include data from all countries in sub‐Saharan Africa, including South Africa, the country with the world's largest HIV epidemic. Nevertheless, our study is the most comprehensive analysis of this topic to date, including 33 countries and more than one million persons. Second, the five questions included in the DHS/AIS that comprise the UNAIDS core indicator do not capture some important aspects of HIV knowledge, such as the availability or efficacy of ART. However, we felt it was important to include these questions in our analysis because of their historical importance as the UNGASS/UNAIDS core indicator and to allow for measuring temporal trends in knowledge of HIV transmission and prevention since 2003. Third, these questions on HIV knowledge could theoretically be misconstrued by respondents and do not comprise a validated multi‐item scale. However, this limitation would only bias our estimates if the extent to which respondents misinterpreted the survey questions has systematically changed over time.In conclusion, we found evidence for only minimal improvements in HIV knowledge over time in sub‐Saharan Africa during the current era of ART scale‐up. Comprehensive HIV knowledge is held by only a minority of respondents, and if current trends hold, levels of comprehensive HIV knowledge will continue to fall well short of the 95% goal set by the United Nations nearly two decades ago. Our findings suggest that interventions to improve HIV knowledge in the general population may be an important component of initiatives to move Africa towards the goal of an AIDS‐free generation. Further study is needed to develop and successfully implement such interventions on a national and regional scale.The authors declare that they have no competing interests.BTC contributed to conceptualization and design of the study, acquisition of data, data analysis and interpretation, and drafting and editing of the article. ACT contributed to design of the study, data analysis and interpretation, and editing of the article. Both authors have read and approved the final manuscript.


The existing literature suggests a critical role for both the right intraparietal sulcus (IPS) and the right temporo‐parietal junction (TPJ) in our ability to attend to multiple simultaneously‐presented lateralized targets (multi‐target attention), and the failure of this ability in extinction patients. Currently, however, the precise role of each of these areas in multi‐target attention is unclear. In this study, we combined the theory of visual attention (TVA) with functional magnetic resonance imaging (fMRI) guided continuous theta burst stimulation (cTBS) in neurologically healthy subjects to directly investigate the role of the right IPS and TPJ in multi‐target attention. Our results show that cTBS at an area of the right IPS associated with multi‐target attention elicits a reduction of visual short‐term memory capacity. This suggests that the right IPS is associated with a general capacity‐limited encoding mechanism that is engaged regardless of whether targets have to be attended or remembered. Curiously, however, cTBS to the right IPS failed to elicit extinction‐like behavior in our study, supporting previous suggestions that different areas of the right IPS may provide different contributions to multi‐target attention. CTBS to the right TPJ failed to induce a change in either TVA parameters or extinction‐like behavior. The importance of this ability is demonstrated impressively in neurological patients suffering from extinction, most commonly as a consequence of right hemispheric brain damage , indicating the rate at which stimuli can be processed, (b) visual short‐term memory (VSTM) capacity (K), indicating the maximum amount of stimuli that can be simultaneously represented in VSTM, (c) spatial distribution of attention (wλ), indicating the direction of the overall spatio‐attentional bias, and (d) top‐down control (α), indicating the attentional preference given to targets over distractors. According to TVA, visual objects are processed in parallel and compete for selection. This selection process is determined by two factors: the processing rate and VSTM capacity (K). Objects with a higher processing rate have a higher probability of winning the race to be encoded in VSTM. The processing speed (C) equals the sum of the processing rates for all objects in the visual field. The processing rate for each individual object reflects the proportion of the total processing capacity allocated to that object , which depends on top‐down control (α) and the direction of the overall spatio‐attentional bias (wλ). The first K elements that enter VSTM will be available for overt report and object processing is terminated when the VSTM capacity limit is reached . The optimal values of these four parameters can be estimated by fitting the TVA model to the data of two simple tasks, the whole report and the partial report of briefly presented letters. The processing speed and VSTM capacity parameters are assessed with the whole report paradigm, where subjects are presented with multiple letters and have to report as many letters as possible. The spatial distribution of attention and top‐down control parameters are assessed with the partial report paradigm. Here, subjects report only target letters, while ignoring distractor letters. The four parameters are quantitatively estimated using a trial‐by‐trial maximum likelihood fitting procedure , paired with increased top‐down control in the ipsilateral visual field. Similarly, Moos, Vossel, Weidner, Sparing, and Fink  and is thus very easy to implement. Surprisingly, however, given this ease of implementation and informativeness, applications of TVA to study the precise contribution of the IPS and TPJ to attention in multi‐target environments are rare. A few studies have, however, applied TVA to assess the contribution of the IPS to selective attention. Hung, Driver, and Walsh  combinedand Fink  combinedand Fink  interpreand Fink  results and Fink . Additioand Fink . These sand Fink  only assThe current study thus aims to elucidate the role of the right IPS and the right TPJ in multi‐target attention and its failure in extinction patients. We combine TVA with functional magnetic resonance imaging (fMRI) guided continuous theta burst transcranial magnetic stimulation (cTBS) to transiently inhibit neural activation at either the right IPS or the right TPJ in neurologically healthy participants. Specifically, we use fMRI to individually define the location of the right IPS and right TPJ area associated with multi‐target attention. Subsequently, we assess the effect of cTBS‐induced transient neuroinhibition at these brain areas on the four TVA parameters and subjects' ability to attend to multiple simultaneously‐presented lateralized targets. Given the scarcity of previous studies using TVA to study the role of the IPS and TPJ in multi‐target attention, deriving precise study predictions is difficult. Nevertheless, based on the current view of extinction as a consequence of both lateralized and nonlateralized deficits, and the results of the studies presented above, we offer the following tentative hypotheses: Firstly, we hypothesize that cTBS to the right IPS will elicit a lateralized reduction of top‐down control, as well as, potentially, a reduction of processing speed and/or VSTM capacity. Secondly, we hypothesize that cTBS to the right TPJ will elicit a spatio‐attentional bias toward the ipsilateral visual field, as well as a reduction in processing speed and VSTM capacity. Finally, we hypothesize that the modulation of these attentional sub‐processes will be accompanied by a reduction in our subjects' ability to attend to multiple simultaneously‐presented lateralized targets.2Each subject performed five experimental sessions (taking place on separate days). In the first session, subjects participated in a fMRI study , allowing us to determine the location of the right IPS and right TPJ area associated with multi‐target attention in each individual subject. In the second session, we applied cTBS at the hand area of the right motor cortex and measured the size of the motor evoked potential (MEP) in each individual subject, allowing us to qualify the effect of cTBS on cortical functioning in our subjects. Finally, in sessions 3–5, subjects participated in a TVA experiment while we applied cTBS at either the right IPS, the right TPJ, or the vertex (as a control location), allowing us to assess the effect of transient neuroinhibition at the IPS and TPJ area associated with multi‐target attention on attentional sub‐processes and our ability to attend to multiple simultaneously‐presented lateralized targets.2.1Forty subjects  participated in the current study. A single subject had to be excluded from the analyses due to failure to comply with the task instruction to fixate on the central fixation cross. Furthermore, four subjects were excluded from further analysis due to insufficient TVA parameter fits see . Thus, 32.2We used a rapid event‐related fMRI localizer to functionally define the location of the right IPS and right TPJ area associated with multi‐target attention in each individual subject. While the fMRI signal was continuously measured, subjects performed a combined visual short‐term memory (VSTM) and object identification task based on the task used by Emrich, Burianova, and Ferber ; see alsThe choice for this task was motivated by two sets of observations from the previous literature: Firstly, previous studies have demonstrated that comparing neural activation during bilateral object identification trials and neural activation during unilateral object identification trials enables isolating the right IPS area associated with attention in multi‐target environments . Additionally, for each subject we sagitally acquired a T1‐weighted Magnetization Prepared Rapid Gradient Echo (MP‐RAGE) anatomical volume  with a flip‐angle of 15°, a TE of 3.4 ms and a TR of 2,000 ms to aid normalization and visualization of the functional data. Preprocessing and statistical analyses were performed with SPM8  implemented in Matlab 2014a . The functional volumes were slice time corrected and motion corrected. Subsequently, the T1‐weighted volume was coregistered with the mean functional volume obtained after realignment. Transforms for warping the coregistered T1‐weighted volume to standard stereotaxic space were computed using the unified segmentation and normalization approach. The resulting transformation parameters were used to warp the functional volumes and structural volumes into stereotaxic space. Finally, the functional volumes were spatially smoothed (8 mm FWHM). Each object presentation condition was modeled using the standard SPM8 hemodynamic response function with temporal and dispersion derivatives. To reduce global noise, the time series of the mean white matter signal was added as a regressor.Functional imaging was performed using a 3T Siemens Magnetom Trio scanner . The fMRI volumes were collected axially with a flip angle of 90°, a time to echo (TE) of 40 ms and a time to repetition (TR) of 2,680 ms. Each fMRI volume contained 33 slices acquired in sequential ascending order with 3 mmIn each individual subject, we defined the location of the right IPS area associated with multi‐target attention by performing a conjunction analysis comparing the neural activity elicited by bilateral object sample displays to the neural activation elicited by unilateral object sample displays  AND ], analogously to the approach taken in de Haan, Bither, et al. ), averag2.3Forty seconds of cTBS has been shown to reliably induce inhibition of neural activity lasting approximately 30 min in neurologically healthy subjects  in the first dorsal interosseous muscle before and after 40 s of cTBS with the aid of an electromyogram . CTBS was applied with a Magstim Superrapid TMS stimulator with integrated two channel muscle evoked potentials (MEP) recording and a 70 mm figure‐of‐eight TMS coil . The positioning of the TMS coil was guided with an optical real‐time navigation system based on a structural MRI scan in each individual subject. The navigation system consisted of a Polaris Position Sensor  and the Localite TMS Navigator Software Package . For MEP data analysis we used the BrainVision‐Analyser  and Matlab R2014a .For cTBS we used the standard protocol as described by Huang et al.  consisti2.4Each subject participated in three cTBS sessions. In each session, we used the same standard cTBS protocol as described for Session 2 (“Effect of cTBS on MEPs”). CTBS was administered at three different cortical locations, with each location being targeted in a separate session taking place on a separate day, and at least 3 days between sessions to avoid potential carry‐over effects. Two of the three cortical locations, the right IPS and the right TPJ, were functionally defined on the basis of the individual results from the functional localizer, as described for Session 1 . The third location was the vertex, which was anatomically defined in each individual (the highest point on the subject's head). This location served to control for potential general effects of cTBS on task performance. The order in which cTBS was applied at the different cortical locations was randomized over subjects.The application of cTBS and the positioning of the TMS coil was identical to that described for Session 2 (“Effect of cTBS on MEPs”). To ensure that subjects maintained stable gaze fixation throughout the task we monitored eye fixation position with the aid of an electrooculogram  and BrainVision‐Recorder . Horizontal electrodes (left and right of the eyes) were used for saccade‐detection and vertical electrodes (above and below left eye) were used for blink control. For EOG data analysis we used the BrainVision‐Analyser  and Matlab R2014a .K) and processing speed (C) were estimated. In the partial report task, the trial sequence was exactly the same, except that either 1, or 2 colored letters were presented (red or green), followed by a pattern mask. Letters and mask subtended 0.75° × 0.75° visual angle and were presented at the corners of an imaginary square of 10° × 10° visual angle. The distance of the letters to the central fixation cross was ~7° visual angle. The two‐letter conditions contained two letters of the same color  or different colors  and these letters were presented either vertically in the same visual field or horizontally with one letter in each visual field. Subjects were instructed to manually enter only the target letters  and ignore the distracter letters . The color of the target and distractor letters was randomly determined for each subject and session. Taken together, five possible stimulus configurations were obtained in the partial report task: 1 target letter alone (Tnone), 2 target letters in the same hemifield (TTsame), 2 target letters in opposite hemifields (TTopp), 1 target letter and 1 distractor letter in the same hemifield (TDsame), and 1 target letter and 1 distractor letter in opposite hemifields (TDopp). In total, 16 different conditions were obtained , and each condition was presented 18 times . Prior to the partial report task, a pretest was used to estimate the individual presentation duration of the stimuli in the main task. This pretest contained 32 Tnone trials where each single letter was presented for a duration of 70 ms. For subjects that performed within a mean accuracy of 60%–80%, stimulus exposure duration was kept at 70 ms in the main experiment. For subjects whose mean accuracy was outside of this range, the exposure duration was adjusted as follows: performance <50%, exposure duration extended to 100 ms; performance between 50 and 60%, exposure duration extended to 86 ms; performance between 80 and 90%, exposure duration shortened to 57 ms; performance above 90%, exposure duration shortened to 43 ms. With the partial report task the parameters top‐down selectivity (α) for the left and right hemifield and spatial distribution of attention (wλ) were estimated, where the parameter wλ is defined as the ratio of left and right target and distractor weights (wL/[wL + wR]). In both tasks, responses were collected with a keyboard and performance accuracy was recorded. The order of the whole report and partial report tasks was randomized over subjects and sessions and during the first TVA session subjects performed several practice trials to familiarize themselves with the tasks.In each session, subjects performed the TVA experiment, consisting of both a whole report and partial report TVA task . As outlined in the introduction, our main aim was to clarify the precise attentional sub‐processes affected after a functional impairment of either the IPS or the TPJ and their relation to our ability to attend to multiple simultaneously‐presented lateralized targets. Thus, as we were primarily interested in assessing the effect of neuroinhibition at either the IPS or the TPJ, and not in directly comparing the effects of neuroinhibition between the IPS and the TPJ, we separately compared TVA parameter estimates following cTBS at the right IPS and TVA parameter estimates following cTBS at the right TPJ with TVA parameter estimates following cTBS to the vertex. Importantly, we did a‐priorily not necessarily expect neuroinhibition at the IPS and the TPJ to differentially modulate either individual TVA parameter estimates or extinction‐like behavior. In fact, based on the current view of extinction as a consequence of both lateralized and nonlateralized deficits, and the results of previous studies, we hypothesized that several TVA parameter estimates , as well as extinction‐like behavior, might be similarly affected following cTBS to the IPS and the TPJ. Thus, directly comparing the effects of neuroinhibition between the IPS and TPJ would potentially have obscured effects that we were interested in.Iext = (P(hit│uni‐left) − P(hit│bil‐left))–(P(hit│uni‐right) − P(hit│bil‐right); taken from Vossel et al., p‐values were Bonferroni corrected for multiple comparisons when appropriate, in which case the corrected p‐values are additionally noted as pcorr.Additionally, from the partial report task, we used the proportion correct (ranging from 0 to 1) during single target (Tnone) presentations in left  and right  visual field, and double target presentations in opposite hemifields (TTopp) to calculate an extinction index according to the following formula 33.1p < .05 FWE corrected for multiple comparisons) and the individual peak coordinates of all subjects (left side), as well as the activation cluster in four representative subjects (right side). In two subjects the IPS coordinates could not be estimated with the conjunction contrast. Instead, we used the group peak coordinate in one subject, and another  contrast in the other subject  to define the location of the IPS. The location of the TPJ was determined by assessing where in the inferior parietal lobe/superior temporal gyrus neural activation was lower during object presentation under high VSTM load than during object presentation under low VSTM load (contrast: low > high). The bottom row of Figure p < .05 FWE corrected for multiple comparisons) and the individual peak coordinates of all subjects (left side), as well as the activation cluster in four representative subjects (right side). The behavioral results of this fMRI localizer session can be found in the The aim of the fMRI localizer session was to functionally define the location of the right IPS and the right TPJ area associated with multi‐target attention in each individual subject. The location of the IPS was determined with the aid of a conjunction analysis, where we assessed where in the right posterior parietal cortex [ AND ] held, that is, higher neural activity during bilateral object presentation than during both unilateral left and unilateral right object presentation. The top row of Figure 3.2https://osf.io/gkysv/.The magnitude of MEP before and after cTBS to the motor cortex gave us a qualitative measure of whether cTBS induced cortical inhibition , or not. In three subjects, we were unable to obtain an MEP measurement in some of the intervals between 0 and 20 min after cTBS. In two subjects, this was due to overheating of the TMS coil . In the remaining subject, this was due to the participant becoming nauseous and subsequently aborting the session (1 out of 5 measurements missing). In these subjects, we calculated the normalized grand average MEP amplitude using the available post‐cTBS intervals. In line with previous observations  to exclude them from further analysis when (a) performance accuracy was below 40% in multiple conditions (indicating possible floor performance), and/or (b) visual inspection revealed a high deviation between observed and predicted values in multiple conditions (indicating a poor model fit). Importantly, this decision was made prior to the statistical analysis of the data, and the authors were blind with respect to the individual TVA parameter estimates and the group‐status (INH or NON‐INH) of the subjects during the decision‐making process. Of the four subjects excluded, three subjects demonstrated an r2 of less than 30%, suggesting that the TVA parameter estimates would have been unlikely to be meaningful in these subjects.We used the horizontal EOG signal to assess whether saccades were present during stimulus presentation. On average, 99.5% (+/− 0.5%) of the trials were free from saccades. Trials with saccades were excluded from analysis. Following generally accepted guidelines, the quality of the TVA model fit, that is, how well the observed data fitted the predicted model, was assessed by the coefficient of determination r2 of 95% (SD = 2%) in the whole report task and 71% (SD = 12%) in the partial report task. Following cTBS at the IPS, the model fit yielded an average r2 of 95% (SD = 2%) in the whole report task and 68% (SD = 15%) in the partial report task. Following cTBS at the TPJ, the model fit yielded an average r2 of 95% (SD = 2%) in the whole report task and 71% (SD = 16%) in the partial report task. These model fits are comparable with those obtained in previous TVA‐based studies with young healthy participants  and stimulus location (left or right), and the between‐subject factor group (INH or NON‐INH). Figure We compared TVA task performance following cTBS at the IPS and TVA task performance following cTBS at the vertex to investigate which attentional sub‐processes were modulated after a transient inhibition of neural activity at the IPS. To statistically assess whether cTBS at the IPS modulated any of the TVA parameter estimates when compared to cTBS at the vertex, we performed mixed‐design ANOVAs with the within‐subject factor cTBS location (IPS or vertex) and the between‐subject factor group (INH or NON‐INH) for the TVA parameter estimates K and F1,33 = 11.279, p = .002, pcorr = .008, ηp2 = .255). Neither the main effect of cTBS location  nor the main effect of group  was significant. To determine the source of this significant interaction, we performed separate paired‐samples t‐tests to assess the effect of cTBS location on TVA parameter estimate K for both the INH and the NON‐INH group. These analyses revealed that cTBS at the IPS significantly reduced the TVA parameter estimate K for the INH group , but not for the NON‐INH group . Thus, for the INH group only, neuroinhibition at the IPS induced a significant reduction of VSTM capacity.For the TVA parameter estimate K, we found a significant interaction between the factors cTBS location and group  nor any of the main effects  was significant. For the TVA parameter estimate C, we found a significant main effect of stimulus location , suggesting lower processing speed for targets in the left visual field than targets in the right visual field. However, neither the three‐way interaction of cTBS location by stimulus location by group  nor any of the two‐way interactions  nor any of the other main effects  was significant. For the TVA parameter α, neither the three‐way interaction of cTBS location by stimulus location by group  nor any of the two‐way interactions  nor any of the main effects  was significant.We found no evidence to suggest that cTBS at the IPS significantly modulated any of the other TVA parameter estimates when compared to cTBS at the vertex. For the TVA parameter estimate F1,33 = 0.153, p = .698, ηp2 = .005) nor a significant main effect of either cTBS location  or group , suggesting that cTBS at the IPS did not modulate multi‐target attention.Additionally, we compared the extinction index following cTBS at the IPS and cTBS at the vertex to investigate whether cTBS at the IPS modulated subjects' ability to attend to multiple simultaneously‐presented lateralized targets. As can be seen in Table p‐value of .05/12 = .004  nor the main effect of cTBS location  nor the main effect of group  was significant. For the TVA parameter estimate C, we again found a significant main effect of stimulus location , suggesting lower processing speed for targets in the left visual field than targets in the right visual field. However, neither the three‐way interaction of cTBS location by stimulus location by group  nor any of the two‐way interactions  nor any of the other main effects  was significant. For the TVA parameter α, neither the three‐way interaction of cTBS location by stimulus location by group  nor any of the two‐way interactions  nor any of the main effects  was significant.We found no evidence to suggest that cTBS at the TPJ significantly modulated any of the TVA parameter estimates when compared to cTBS at the vertex. For the TVA parameter estimates F1,33 = 0.896, p = .351, ηp2 = .026) nor a significant main effect of either cTBS location  or group , suggesting that cTBS at the TPJ did not modulate multi‐target attention.Additionally, identically to the analyses performed to investigate the effects of cTBS at the IPS, we compared the extinction index following cTBS at the TPJ and cTBS at the vertex to investigate whether cTBS at the TPJ modulated subjects' ability to attend to multiple simultaneously‐presented lateralized targets. As can be seen in Table wλ in the INH group  tended to show an increase in the extinction index following cTBS at the TPJ, whereas individuals with a baseline rightward spatio‐attentional bias (wλ < .5) tended to show a decrease in the extinction index  showed a negative extinction index , whereas subjects with a right‐ward spatio‐attentional bias (wλ < .5) showed a positive extinction index . Compared to this baseline, cTBS at the TPJ elicited a decrease in the TVA parameter estimate wλ for subjects with a baseline left‐ward spatio‐attentional bias, which was accompanied by an increase in the extinction index , which was accompanied by a shift of the extinction index toward 0  led to a reduction of behavioral variance without affecting the behavioral mean. Had the effect of cTBS on the extinction index depended on individual differences in baseline attentional performance, we would have expected cTBS at the TPJ to instead have increased behavioral variance. Thus, this again suggests that the absence of an effect of cTBS at the right TPJ on extinction‐like behavior was not simply due to the effect being buffered by existing differences in baseline attentional performance.To again assess whether the effect of cTBS on the extinction index depended on individual differences in baseline attentional performance, we performed exploratory analyses where we correlated the cTBS‐induced change in the extinction index  with each of the baseline TVA parameter estimates obtained following cTBS to the vertex, in both the INH and the NON‐INH group. These Spearman's rank order correlation analyses revealed a significant correlation between the effect of cTBS on the extinction index and the baseline TVA parameter estimate 4In the current study, we aimed to elucidate the role of the IPS and the TPJ in our ability to attend to multiple simultaneously‐presented lateralized targets, and the failure of this ability in extinction patients. In neurologically healthy subjects, we combined TVA with fMRI‐guided cTBS to transiently inhibit neural activation at either the right IPS or the right TPJ. Specifically, we used fMRI to individually define the location of the right IPS and right TPJ area associated with multi‐target attention. Subsequently, we assessed the effect of cTBS‐induced transient neuroinhibition at these brain areas on attentional sub‐processes as modeled using TVA, as well as multi‐target attention. Our study yielded several important findings.4.1r values > .8) between the amount of targets subjects can attend and the amount of target representations subjects can encode and maintain in VSTM  following transient neuroinhibition at the right IPS, particularly in subjects responsive to cTBS. That is, the negative effect of adding a distractor letter to the display on target letter performance was numerically reduced following cTBS at the IPS. Such counterintuitive facilitatory effects of neuroinhibition have previously been interpreted as a consequence of a decrease in the global cortical excitation level  even at the longest stimulus exposure duration used in the whole report task (regardless of cTBS location), our failure to find evidence of impaired attentional selection or extinction‐like behavior cannot simply be attributed to ceiling effects. Moreover, the results of our exploratory correlation analyses again suggest that the effect of cTBS at the right TPJ on extinction‐like behavior was not simply buffered by existing differences in baseline attentional performance. Our failure to find evidence of impaired attentional selection or extinction‐like behavior following a transient inhibition of neural activity at the right TPJ is in direct contrast with the results from a multitude of studies that argue for an important role of the TPJ in attentional selection  beyond the motor cortex. Thus, prior to our main TVA sessions, we measured the effect of cTBS at the motor cortex and, in each individual subject, assessed whether cTBS resulted in an inhibition of cortical function. Subsequently, we separately assessed the behavioral effects of cTBS at our regions of interest for the subjects that showed evidence of neural inhibition following cTBS at the motor cortex and those that did not. In our study, 37% (13 out of 35 subjects) of the subjects demonstrated neural inhibition following cTBS at the motor cortex, which is in line with what Hamada et al.  and McAlAppendix S1: Supplementary InformationClick here for additional data file.


HIV infection is being rolled out in Africa. The uptake of PrEP to date has varied across populations and locations. We seek to understand the drivers of demand for PrEP through analysis of qualitative data collected in conjunction with a PrEP demonstration project involving East African HIV serodiscordant couples. Our goal was to inform demand creation by understanding what PrEP means – beyond HIV prevention – for the lives of users.Pre‐exposure prophylaxis (PrEP) to prevent EP and antiretroviral therapy (ART) delivery in which time‐limited PrEP served as a “bridge” to long‐term ART. Uninfected partners in HIV serodiscordant couples were offered PrEP at baseline and encouraged to discontinue once infected partners had taken ART for six months. We conducted 274 open‐ended interviews with 93 couples at two Ugandan research sites. Interviews took place one month after enrolment and at later points in the follow‐up period. Topics included are as follows: (1) discovery of serodiscordance; (2) decisions to accept/decline PrEP and/or ART; (3) PrEP and ART initiation; (4) experiences of using PrEP and ART; (5) PrEP discontinuation; (6) impact of PrEP and ART on the partnered relationship. Interviews were audio‐recorded and transcribed. We used an inductive, content analytic approach to characterize meanings of PrEP stemming from its effectiveness for HIV prevention. Relevant content was represented as descriptive categories.The Partners Demonstration Project evaluated an integrated strategy of PrHIV serodiscordance resulted in fear of HIV transmission for couples, which led to loss of sexual intimacy in committed relationships, and to abandonment of plans for children. As a result, partners became alienated from each other. PrEP countered the threat to the relationship by reducing fear and reinstating hopes of having children together. Condom use worked against the re‐establishment of intimacy and closeness. By increasing couples’ sense of protection against HIV infection and raising the prospect of a return to “live sex” (sex without condoms), PrEP was perceived by couples as solving the problem of serodiscordance and preserving committed relationships.Discovery of EP may be those that address the everyday life priorities of potential users in addition to HIV prevention.The most effective demand creation strategies for PrNCT02775929 As of July 2018, the number of PrEP initiations in Kenya stood at two‐thirds of national targets, in Zimbabwe at 50% of targets, and in South Africa at 41% of targets Retention is developing into a major challenge, with individuals initiating or expressing interest in PrEP choosing not continue due to medication side effects, fear of stigma, negative attitudes from clinical staff and other considerations demand creationIn sum, limited initial demand is emerging as an important influence on the uptake of PrEP in Africa. Activities aimed at generating interest in new products and technologies by linking them to the priorities of prospective users are known as 22.1This was a qualitative study carried out in conjunction with the Partners Demonstration Project. The Partners Demonstration Project  was an open‐label evaluation of integrated delivery of PrEP and antiretroviral therapy (ART) for higher‐risk HIV serodiscordant couples in Kenya and Uganda The integrated delivery strategy offered time‐limited PrEP to uninfected partners in serodiscordant couples as a “bridge” to long‐term ART in infected partners. Uninfected partners were offered PrEP at baseline and encouraged to discontinue once infected partners had taken ART for six months. Counsellors also encouraged condom use to prevent sexually transmitted infections and unintended pregnancies 2.2Purposeful sampling was used to identify participants in the qualitative study 2.3Qualitative data collection for this study took place at the Partners Demonstration Project's two Ugandan sites: the Infectious Diseases Institute – Kasangati, in Kampala; and Kabwohe Clinical Research Center, in the rural southwest. Multiple open‐ended interviews were carried out with couples participating in the qualitative study.Interviews took place approximately one month after enrolment in the Partners Demonstration Project, and at later points in the follow‐up period. Examples of interview topics included: (1) discovery of serodiscordance; (2) decisions to accept/decline PrEP and/or ART; (3) experiences of PrEP and ART initiation; (4) experiences of using PrEP and ART; (5) PrEP discontinuation; and (6) the impact of PrEP and ART on the partnered relationship. Partners took part in initial interviews together, to allow insight into relationship dynamics. Subsequent interviews were a mix of individual and joint sessions, depending on the topics to be discussed. Two hundred and seventy‐four interviews were completed. One hundred and forty‐eight were interviews with both members of the couple; 126 were individual interviews.Interviews were conducted by trained Ugandan research assistants in local languages , using interview guides. Each interview type had a different guide, tailored to the experience being investigated. In the initial joint interviews, the interviewer took notes on relationship dynamics, guided by a predesignated list of relationship characteristics.Interviews were conducted in private settings in locations selected by interviewees. Participants provided written consent for interviews, which were audio‐recorded and lasted about an hour. Audio‐recordings were transcribed into English by the research assistants. Transcripts were reviewed for content and technique in weekly feedback phone calls and emails with a supervisor to ensure data quality. Besides the transcripts, the research assistants prepared “debriefs” summarizing interview content. Interview data were collected from November 2013 through December 2016.2.4An inductive, content analytic approach was used to analyse the qualitative data This process led to the preliminary specification of concepts addressing the research question. Coded and transcript data were then repeatedly reviewed to assign examples to the preliminary concepts. The addition of examples served to refine and elaborate the concepts, transforming them into descriptive categories. Statements summarizing the content of each category were added, along with evidence in the form of illustrative quotes from interview transcripts. Finally, the categories were linked to “tell the story” of the meanings of PrEP that emerged from the analysis.2.5Ethical approvals were obtained from the Committee on Human Studies, Harvard Medical School, Boston MA; the National HIV/AIDS Research Committee of the Ugandan National Council for Science and Technology, Kampala; and the University of Washington Institutional Review Board, University of Washington, Seattle, WA.33.1Couples eligible for the Partners Demonstration Project were ≥18 years of age, sexually active and reported intending to remain together.HIV‐infected and uninfected partners in the qualitative study were in their early thirties. Approximately half (46%) of uninfected partners were female. Median time since discovering serodiscordant status was two months at baseline (Range: 1 to 12). Median time living together was three years (Range: 1 to 9). Almost all couples  reported being married to each other. Fifty‐three percent of couples (N = 49) had children together at baseline.Among qualitative study participants, 88% (N = 82) of uninfected partners initiated PrEP at Partners Demonstration Project enrolment. PrEP initiation increased to 92% (N = 86) during the follow‐up period. Sixty‐six percent N = 61) of infected partners among qualitative study participants were eligible for ART at enrolment. Sixty‐seven percent (N = 40) of eligible individuals initiated ART at enrolment; all initiated ART during the follow‐up period. Twenty‐one (23%) couples in the qualitative sample reported ending their relationship after enrolling in the Partners Demonstration Project  programme for distribution is spearheaded by the AIDS Control Programme (ACP) of the Ministry of Health, which has worked to create demand through training for healthcare providers, increasing capacity for HIV testing in clinics, and instituting a clinic accreditation programme. Scale‐up is taking place in public health clinics across the country; the number of clinics distributing PrEP is being increased each year. In October 2018, reported PrEP initiations total 9000 to 9500 In Kenya, a public messaging campaign directly targeting prospective PrEP users plays a prominent role in scale‐up. The adoption of positive rather than “fear‐based” messaging is a core principle of the campaign. Positive messaging highlights PrEP's contribution to happiness and wellbeing, rather than its role in reducing the risk of acquiring a potentially life‐threatening disease. Messaging materials are distributed widely outside as well as inside the healthcare system Fitting PrEP demand creation strategies to the life priorities and meanings of PrEP for users is a principle that spans specific population groups. However, it requires understanding the life experiences and goals of group members, from their own points of view. Research identifying the nurturing of intimate relationships as a priority for couples – heterosexual and MSM – is a first step. Similar inquiries focusing on other key populations may help to effectively address suboptimal PrEP uptake and/or retention in those groups The opportunity to investigate couples’ direct experiences with PrEP through multiple interviews conducted both jointly and individually is an important strength of this study, as they add to validity of the findings and the level of detail presented. However, we acknowledge that these data reflect the perspectives of Ugandan serodiscordant couples who had recently learned of and mutually disclosed their HIV serodiscordant status, who in most cases defined themselves as couples (rather than as having separated), and who were participating in a PrEP demonstration project. The experiences of couples who are not research participants, have long lived with serodiscordance, do not remain together, and/or whose nationalities and cultural backgrounds differ may not be the same. The similarities observed for Kenyan serodiscordant couples 5Because of its effectiveness in preventing HIV transmission, PrEP represented a solution to the problem of serodiscordance for Ugandan couples. Decreased fear during sex, renewed hopes for family building, and the prospect of eventual “live sex” were intermediate benefits serving this larger end. The most effective PrEP demand creation strategies may be those that meaningfully address the everyday life priorities of potential users, as well as HIV prevention. Understanding the meanings of PrEP for potential users can inform demand creation for PrEP scale‐up.The authors have no competing interests to declare.NCW and MAW designed the qualitative research. ENJ and NCW analysed the data for this report, and wrote and revised the manuscript. MAW and EEP provided general supervision for the data collection process in Uganda, contributed to the data analytic process and reviewed and commented on drafts of the manuscript. TRM, ETK and SBA supervised data collection at the qualitative study sites. JMB and CLC provided feedback on emerging findings from the qualitative study and reviewed and provided comments on the manuscript. All authors critically reviewed and approved the final version.