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1.
To date, developmental research on groups has focused mainly on in-group biases and intergroup relations. However, little is known about children’s general understanding of social groups and their perceptions of different forms of group. In this study, 5- to 6-year-old children were asked to evaluate prototypes of four key types of groups: an intimacy group (friends), a task group (people who are collaborating), a social category (people who look alike), and a loose association (people who coincidently meet at a tram stop). In line with previous work with adults, the vast majority of children perceived the intimacy group, task group, and social category, but not the loose association, to possess entitativity, that is, to be a ‘real group.’ In addition, children evaluated group member properties, social relations, and social obligations differently in each type of group, demonstrating that young children are able to distinguish between different types of in-group relations. The origins of the general group typology used by adults thus appear early in development. These findings contribute to our knowledge about children''s intuitive understanding of groups and group members'' behavior.Young children grow up in a complex social world in which they are constantly flooded with social information. Our social world is composed not only of individuals but of an array of different relationships and social groupings. One challenge for children is to decipher which of these social groupings are meaningful. People can appear to be a group from the outside, for example simply because they are in close proximity to each other, but they can be connected with each other at different levels: they can be kin or friends, be on the same sports or work team, be part of the same national or language group, or they can be associated with each other only briefly and loosely when, for instance, they take the same bus to get to the airport, or line up at a counter at the same time. Determining the type of group to which an association of people belongs is not only crucial for being able to understand individual group members’ behavior but can also be a short-cut to predicting how group members will relate to each other. For example, one can expect kin or friends to be loyal to each other, but one might not expect this about people who happen to be lining up at a counter at the same time. Another important form of predictions that can be drawn from social groupings, but which has been understudied in previous research (see also [1]), regards the grouping as a whole. For example, a friendship is supposed to be a longer-lasting, more coherent entity than a gathering in front of a counter.When it comes to the perception of social groupings, Lickel and colleagues [2] have argued that adults apply a folk typology, in which they intuitively distinguish between four qualitatively different types of groups. In support of this idea, Lickel at el. [3] investigated how adult participants sorted 40 examples of real-life groups, and how they rated each of these groups on a set of eight group characteristics such as shared goals, similarity of group members, interaction among group members, and group size. They found that participants distinguished four basic types of groups: intimacy groups (such as families and friends), task groups (such as work or sports teams), social categories (such as women or U.S. citizens), and loose associations (such as people waiting in line at a counter). Participants associated different group characteristics with each group type, for example a long duration and high levels of interaction for intimacy groups, common goals and interaction in task groups, large size and member similarity for social categories, and short duration and low levels of similarity and common goals for loose associations (for an overview, see [2]). Related research has shown that adults treat some social groupings as entities [46]. The extent to which a group appears to be a coherent entity and therefore possesses a quality of “groupness” has been referred to as “entitativity” [25, 7]. Lickel and colleagues showed that the four types of groups were perceived by adults to have different levels of entitativity, with the highest level for intimacy groups, followed by task groups, social categories, and loose associations.This group typology has received further support and validation from work in anthropology [8, 9]. Interdisciplinary work has linked these different types of groups to different relational models that are more or less prominent within each group type [10]. For example, communal sharing, a relationship in which I see “what is mine as yours” is more pronounced in intimacy groups than in other types of groups. It has been argued that children do not develop a fully-fledged concept of these different relational models before nine or ten years of age [8, 9].Despite the theoretical importance of this group typology, very little research has investigated its origins in childhood. Instead, developmental research on group cognition in young children has focused mainly on children’s in-group biases, that is, their preference for members of their own group over members of other groups. Research in this tradition has shown that children prefer members of their own group on a variety of implicit and explicit measures [1114]. Another line of research focuses on the inferences children draw about individuals based on their group membership. For example, 4- to 6-year-old children predict what a person will do, like, or intend on the basis of that person’s gender, race, or ethnicity [1517]. Children also use information about group membership to make inferences about social interactions: Knowing that two individuals are either from the same or from two different groups influences their prediction about whether those individuals will harm each other (around 4 years; [18]), help each other (from 6 years; [18]), or be friends with each other (from 7 years; [19]).However, this body of research leaves at least three significant gaps in our knowledge about children’s understanding of groups. First, previous research has focused primarily on just one type of group: the one Lickel and colleagues refer to as social categories, thus limiting what we can conclude about children’s understanding of group relations more generally (although see, e.g., [7, 20, 21], for work on preferential behavior towards intimacy and task group members). Second, the main focus of this previous research has been on children’s attitudes and expectations about in-group as compared with out-group members. However, as illustrated in our introductory examples, relationships among members of an in-group may differ in systematic ways depending on the type of in-group to which they belong. Finally, previous work has focused mainly on children’s perceptions of and expectations about individual group members rather than on their perceptions of and expectations about the group as a whole. It is thus important for our understanding of the development of group psychology to ask whether children distinguish different types of social groups and whether they expect relationships within and characteristics of these types of groups to differ from each other.One exception to this general trend is a study conducted by Svirydzenka and colleagues [7]. They found that 10-year-old children intuitively distinguish the same four main types of groups as adults: intimacy groups, task groups, social categories, and loose associations. They also judged the level of entitativity of different group types in similar ways as adults, but their assessments seemed to rely on group characteristics that were more perceptually salient (for example the level of interaction) than adults, who focused on more abstract features such as the importance of the group for its members [22].Inspired by this study and Lickel and colleagues’ work [3], we investigated whether the origins of this folk theory of groups could be seen even in children as young as 5 to 6 years of age. This is an important age in the development of group cognition as 5 to 6 years appears to be just at the border of explicit group understanding. It is at this age that children first show a more general preference for in-group members, even in more abstract and novel groups (in the minimal group paradigm; [21, 23]). Furthermore, it is also at this age that children first become able to predict intergroup relations in third party contexts at least for social categories (e.g., [16, 18]).Thus our objective was to investigate whether, in addition to these preferences and expectations, children of this age also have a more general understanding of groups and different types of group–in other words, an early folk typology of groups. Several prominent theoretical accounts of the origins of intergroup psychology postulate substantial development between the age group in our study and the youngest age, so far, at which a group typology has been found, 10 years [2426]. However, given their relatively sophisticated abilities in other areas of group cognition, we predicted that already by 5 to 6 years of age, children would be able to make subtle distinctions between different types of groups and use this understanding in order to make inferences about group members’ behaviors within different group types.As a first step, we measured children’s spontaneous definition of a group. We did this to investigate children’s naïve, spontaneous ideas about groups, before presenting them with different group types. We predicted that children would be able to give some appropriate examples of groups and were especially interested in whether they would focus on one particular example or definition when thinking about groups (e.g., mention just one group type), or whether they would be able to give a more abstract definition (covering all group types, such as “a collection of people”). Second, because recent work has shown that 5-year-old children have comparable preferences for two types of group members–task group members and social category members [21]–we investigated which of these two examples (operationalized as people who work together vs. people who are similar to each other) children thought was most representative of a group. Third, we investigated whether preschool children would see an intimacy group, a task group, a social category, and a loose association as qualitatively different.It was impossible, given the young age of our participants, to adopt the exact methods of previous studies, which used complex tasks such as sorting of examples of groups and rating multiple group characteristics for each example. To simplify the procedure so that young children would understand it, we thus created a prototype for each of the four types of groups and asked children to judge these prototypes on entitativity and 12 other group characteristics. These group characteristics were generally inspired by the characteristics Lickel et al. [3] and Svirydzenka et al. [7] chose. However, in addition, we asked about several further characteristics that are important topics in recent work on the developmental origins of group psychology (e.g., [20, 2729]) and anthropology [8, 9]. There were four main sets of group characteristics. The first three involved judgments and predictions about individual group members and group member relationships (see, e.g., [27]). The first set involved judgments about social obligations and prosocial behaviors among group members (helping, sharing, and loyalty; e.g., [18, 20, 28, 30]). The second involved the quality of group members’ social relationships (liking, familiarity, interdependence, and joint goals; [7, 31]). The third involved properties marking fundamental similarities among group members (group member similarity, shared preferences, and common knowledge; [29, 32, 33]). The fourth set, in contrast, involved traits of the group itself, concerning characteristics that apply to the group as a whole, rather than to individual members (permeability, continuance, and entitativity; [3]). We predicted generally that children’s perceptions of and expectations about groups would be contingent upon the type of group they were presented with and that they would recognize that a loose association was not a real group.  相似文献   

2.
This work aimed to analyze the rate of disclosure to relatives and friends over time and to identify factors affecting disclosure among seropositive adults initiating antiretroviral therapy (ART) in rural district hospitals in the context of decentralized, integrated HIV care and task-shifting to nurses in Cameroon. Stratall was a 24-month, randomized, open-label trial comparing the effectiveness of clinical monitoring alone with laboratory plus clinical monitoring on treatment outcomes. It enrolled 459 HIV-infected ART-naive adults in 9 rural district hospitals in Cameroon. Participants in both groups were sometimes visited by nurses instead of physicians. Patients with complete data both at enrolment (M0) and at least at one follow-up visit were included in the present analysis. A mixed Poisson regression was used to estimate predictors of the evolution of disclosure index over 24 months (M24).The study population included 385 patients, accounting for 1733 face-to-face interviews at follow-up visits from M0 to M24. The median [IQR] number of categories of relatives and friends to whom patients had disclosed was 2 [1][3] and 3 [2][5] at M0 and M24 (p-trend<0.001), respectively. After multiple adjustments, factors associated with disclosure to a higher number of categories of relatives and friends were as follows: having revealed one’s status to one’s main partner, time on ART, HIV diagnosis during hospitalization, knowledge on ART and positive ratio of follow-up nurse-led to physician-led visits measuring task-shifting. ART delivered in the context of decentralized, integrated HIV care including task-shifting was associated with increased HIV serological status disclosure.  相似文献   

3.
Russian Federation’s (RF) HIV epidemic is the fastest growing of any country. This study explores factors associated with high HIV risk behavior in tuberculosis (TB) patients with alcohol use disorders in Tomsk, RF. This analysis was nested within the Integrated Management of Physician-delivered Alcohol Care for TB Patients (IMPACT, trial number NCT00675961) randomized controlled study of integrating alcohol treatment into TB treatment in Tomsk. Demographics, HIV risk behavior (defined as participant report of high-risk intravenous drug use and/or multiple sexual partners with inconsistent condom use in the last six months), clinical data, alcohol use, depression and psychosocial factors were collected from 196 participants (161 male and 35 female) at baseline. Forty-six participants (23.5%) endorsed HIV risk behavior at baseline. Incarceration history(Odds Ratio (OR)3.93, 95% confidence interval (CI) 1.95, 7.95), age under 41 (OR:2.97, CI:1.46, 6.04), drug addiction(OR: 3.60 CI:1.10, 11.77), history of a sexually transmitted disease(STD)(OR 2.00 CI:1.02, 3.90), low social capital (OR:2.81 CI:0.99, 8.03) and heavier alcohol use (OR:2.56 CI: 1.02, 6.46) were significantly more likely to be associated with HIV risk behavior at baseline. In adjusted analysis, age under 41(OR: 4.93, CI: 2.10, 11.58), incarceration history(OR: 3.56 CI:1.55, 8.17) and STD history (OR: 3.48, CI: 1.5, 8.10) continued to be significantly associated with HIV risk behavior. Understanding HIV transmission dynamics in Russia remains an urgent priority to inform strategies to address the epidemic. Larger studies addressing sex differences in risks and barriers to protective behavior are needed.  相似文献   

4.
BackgroundDefinitive endoderm (DE) is one of the three germ layers which during in vivo vertebrate development gives rise to a variety of organs including liver, lungs, thyroid and pancreas; consequently efficient in vitro initiation of stem cell differentiation to DE cells is a prerequisite for successful cellular specification to subsequent DE-derived cell types [1, 2]. In this study we present a novel approach to rapidly and efficiently down regulate pluripotency genes during initiation of differentiation to DE cells by addition of dimethyl sulfoxide (DMSO) to Activin A-based culture medium and report its effects on the downstream differentiation to hepatocyte-like cells.ResultsAddition of DMSO to the Activin A-based medium during DE specification resulted in rapid down regulation of the pluripotency genes OCT4 and NANOG, accompanied by an increase expression of the DE genes SOX17, CXCR4 and GATA4. Importantly, the expression level of ALB in DMSO-treated cells was also higher than in cells which were differentiated to the DE stage via standard Activin A treatment.  相似文献   

5.

Background

With the persistent challenges towards controlling the HIV epidemic, there is an ongoing need for research into HIV vaccines and drugs. Sub-Saharan African countries - worst affected by the HIV pandemic - have participated in the conduct of clinical trials for HIV vaccines. In Kenya, the Kenya AIDS Vaccine Initiative (KAVI) at the University of Nairobi has conducted HIV vaccine clinical trials since 2001.

Methodology

Participants were recruited after an extensive informed consent process followed by screening to determine eligibility. Screening included an assessment of risk behavior, medical history and physical examination, and if clinically healthy, laboratory testing. In the absence of locally derived laboratory reference ranges, the ranges used in these trials were derived from populations in the West.

Principal findings

Two hundred eighty-one participants were screened between 2003 and 2006 for two clinical trials. Of these, 167 (59.4%) met the inclusion/exclusion criteria. Overall, laboratory abnormalities based on the non-indigenous laboratory references used were the most frequent reasons (61.4%) for ineligibility. Medical abnormalities contributed 30.7% of the total reasons for ineligibility. Based on the laboratory reference intervals now developed from East and Southern Africa, those ineligible due to laboratory abnormalities would have been 46.3%. Of the eligible participants, 18.6% declined enrolment.

Conclusions

Participant recruitment for HIV vaccine clinical trials is a rigorous and time-consuming exercise. Over 61% of the screening exclusions in clinically healthy people were due to laboratory abnormalities. It is essential that laboratory reference ranges generated from local populations for laboratory values be used in the conduct of clinical trials to avoid unnecessary exclusion of willing participants and to avoid over-reporting of adverse events for enrolled participants.

Trial registration

Protocol IAVI VRC V001 [1]. ClinicalTrials.gov NCT00124007 Protocol IAVI 010 [2] (registration with ClincalTrials.gov is in progress) Protocols IAVI 002 and IAVI 004 are Phase 1 trials only mentioned in introductory paragraphs; details will not be reported. Registration was not required when they were conducted.  相似文献   

6.

Background

Depression is a leading contributor to the burden of disease worldwide, a critical barrier to HIV prevention and a common serious HIV co-morbidity. However, depression screening and treatment are limited in sub-Saharan Africa, and there are few population-level studies examining the prevalence and gender-specific factors associated with depression.

Methods

We conducted a cross-sectional population-based study of 18–49 year-old adults from five districts in Botswana with the highest prevalence of HIV-infection. We examined the prevalence of depressive symptoms, using a Hopkins Symptom Checklist for Depression (HSCL-D) score of ≥1.75 to define depression, and correlates of depression using multivariate logistic regression stratified by sex.

Results

Of 1,268 participants surveyed, 25.3% of women and 31.4% of men had depression. Among women, lower education (adjusted odds ratio [AOR] 2.07, 95% confidence interval [1.30–3.32]), higher income (1.77 [1.09–2.86]), and lack of control in sexual decision-making (2.35 [1.46–3.81]) were positively associated with depression. Among men, being single (1.95 [1.02–3.74]), living in a rural area (1.63 [1.02–2.65]), having frequent visits to a health provider (3.29 [1.88–5.74]), anticipated HIV stigma (fearing discrimination if HIV status was revealed) (2.04 [1.27–3.29]), and intergenerational sex (2.28 [1.17–4.41]) were independently associated with depression.

Discussion

Depression is highly prevalent in Botswana, and its correlates are gender-specific. Our findings suggest multiple targets for screening and prevention of depression and highlight the need to integrate mental health counseling and treatment into primary health care to decrease morbidity and improve HIV management efforts.  相似文献   

7.

Background

In 1997, we found a higher prevalence of HIV among female than among male injection drug users in Vancouver. Factors associated with HIV incidence among women in this setting were unknown. In the present study, we sought to compare HIV incidence rates among male and female injection drug users in Vancouver and to compare factors associated with HIV seroconversion.

Methods

This analysis was based on 939 participants recruited between May 1996 and December 2000 who were seronegative at enrolment with at least one follow-up visit completed, and who were studied prospectively until March 2001. Incidence rates were calculated using the Kaplan–Meier method. The Cox proportional hazards regression model was used to identify independent predictors of time to HIV seroconversion.

Results

As of March 2001, seroconversion had occurred in 110 of 939 participants (64 men, 46 women), yielding a cumulative incidence rate of HIV at 48 months of 13.4% (95% confidence interval [CI] 11.0%–15.8%). Incidence was higher among women than among men (16.6% v. 11.7%, p = 0.074). Multivariate analysis of the female participants'' practices revealed injecting cocaine once or more per day compared with injecting less than once per day (adjusted relative risk [RR] 2.6, 95% CI 1.4–4.8), requiring help injecting compared with not requiring such assistance (adjusted RR 2.1, 95% CI 1.1–3.8), having unsafe sex with a regular partner compared with not having unsafe sex with a regular partner (adjusted RR 2.9, 95% CI 0.9–9.5) and having an HIV-positive sex partner compared with not having an HIV-positive sex partner (adjusted RR 2.7, 95% CI 1.0–7.7) to be independent predictors of time to HIV seroconversion. Among male participants, injecting cocaine once or more per day compared with injecting less than once per day (adjusted RR 3.3, 95% CI 1.9–5.6), self-reporting identification as an Aboriginal compared with not self-reporting identification as an Aboriginal (adjusted RR 2.5, 95% CI 1.4–4.2) and borrowing needles compared with not borrowing needles (adjusted RR 2.0, 95% CI 1.1–3.4) were independent predictors of HIV infection.

Interpretation

HIV incidence rates among female injection drug users in Vancouver are about 40% higher than those of male injection drug users. Different risk factors for seroconversion for women as opposed to men suggest that sex-specific prevention initiatives are urgently required.Recent reports in Canada and numerous other countries indicate that HIV is increasingly affecting women.1 Before 1995, adult women in Canada had 9.6% of all positive HIV tests for which the age and sex of the person being tested were known. By 1995, this proportion had increased to 18.5% and reached 23.9% in 2000. In addition, 39% of all new HIV infections among women in 2000 were attributed to injection drug use.2 These data are consistent with findings in the United States where, in 1999, women accounted for 23% of all reported AIDS cases in adults, of which 42% were attributed to injection drug use.3These data clearly indicate that the face of the epidemic is changing. Whereas some factors unique to the transmission of HIV to women are known, basic and behavioural research efforts addressing sex-related and drug-related vulnerabilities among female injection drug users (IDUs) are lacking.4 At a time when women''s vulnerability to HIV infection is becoming increasingly apparent worldwide,5,6 a better understanding of the processes and factors that cause drug-related harm among women in industrialized countries is urgently required.Since the mid-1990s, the Downtown Eastside of Vancouver, British Columbia, has experienced an explosive and ongoing HIV epidemic among IDUs with annual HIV incidence rates reaching as high as 19% in 1997.7,8 When subjects were enrolled in the Vancouver Injection Drug User Study (VIDUS), it was found that the baseline HIV prevalence was higher among women than men (35.2% v. 25.8%).7 Follow-up of this cohort now allows an investigation aimed at identifying the predictors of HIV seroconversion among female and male IDUs. Therefore, we sought to compare HIV incidence rates among male and female IDUs in Vancouver and to compare risk factors associated with HIV seroconversion.  相似文献   

8.
BackgroundAlcohol consumption has a disinhibiting effect that may make sexual risk behaviors and disease transmission more likely. The characteristics of alcohol-serving outlets (e.g. music, dim lights, lack of condoms) may further encourage risky sexual activity. We hypothesize that frequenting alcohol outlets will be associated with HIV risk.MethodsIn a sample of 2,533 school-attending young women in rural South Africa, we performed a cross-sectional analysis to examine the association between frequency of alcohol outlet visits in the last six months and four outcomes related to HIV risk: number of sex partners in the last three months, unprotected sex acts in the last three months, transactional sex with most recent partner, and HSV-2 infection. We also tested for interaction by alcohol consumption.ResultsVisiting alcohol outlets was associated with having more sex partners [adjusted odds ratio (aOR), one versus zero partners (95% confidence interval (CI)): 1.51 (1.21, 1.88)], more unprotected sex acts [aOR, one versus zero acts (95% CI): 2.28 (1.52, 3.42)], higher levels of transactional sex [aOR (95% CI): 1.63 (1.03, 2.59)], and HSV-2 infection [aOR (95% CI): 1.30 (0.88, 1.91)]. In combination with exposure to alcohol consumption, visits to alcohol outlets were more strongly associated with all four outcomes than with either risk factor alone. Statistical evidence of interaction between alcohol outlet visits and alcohol consumption was observed for all outcomes except transactional sex.ConclusionsFrequenting alcohol outlets was associated with increased sexual risk in rural South African young women, especially when they consumed alcohol. Sexual health interventions targeted at alcohol outlets may effectively reach adolescents at high risk for sexually transmitted infections like HIV and HSV-2.

Trial Registration

HIV Prevention Trials Network HPTN 068  相似文献   

9.

Background

Treatment outcomes for multidrug-resistant Mycobacterium Tuberculosis (MDRTB) are generally poor compared to drug sensitive disease. We sought to estimate treatment outcomes and identify risk factors associated with poor outcomes in patients with MDRTB.

Methodology/Principal Findings

We performed a systematic search (to December 2008) to identify trials describing outcomes of patients treated for MDRTB. We pooled appropriate data to estimate WHO-defined outcomes at the end of treatment and follow-up. Where appropriate, pooled covariates were analyzed to identify factors associated with worse outcomes. Among articles identified, 36 met our inclusion criteria, representing 31 treatment programmes from 21 countries. In a pooled analysis, 62% [95% CI 57–67] of patients had successful outcomes, while 13% [9][17] defaulted, 11% [9][13] died, and 2% [1][4] were transferred out. Factors associated with worse outcome included male gender 0.61 (OR for successful outcome) [0.46–0.82], alcohol abuse 0.49 [0.39–0.63], low BMI 0.41[0.23–0.72], smear positivity at diagnosis 0.53 [0.31–0.91], fluoroquinolone resistance 0.45 [0.22–0.91] and the presence of an XDR resistance pattern 0.57 [0.41–0.80]. Factors associated with successful outcome were surgical intervention 1.91 [1.44–2.53], no previous treatment 1.42 [1.05–1.94], and fluoroquinolone use 2.20 [1.19–4.09].

Conclusions/Significance

We have identified several factors associated with poor outcomes where interventions may be targeted. In addition, we have identified high rates of default, which likely contributes to the development and spread of MDRTB.  相似文献   

10.

Background

Obstructive sleep apnoea (OSA) is frequently observed in severe asthma but the causal link between the 2 diseases remains hypothetical. The role of OSA-related systemic and airway neutrophilic inflammation in asthma bronchial inflammation or remodelling has been rarely investigated. The aim of this study was to compare hallmarks of inflammation in induced sputum and features of airway remodelling in bronchial biopsies from adult patients with severe asthma with and without OSA.

Materials and Methods

An overnight polygraphy was performed in 55 patients referred for difficult-to-treat asthma, who complained of nocturnal respiratory symptoms, poor sleep quality or fatigue. We compared sputum analysis, reticular basement membrane (RBM) thickness, smooth muscle area, vascular density and inflammatory cell infiltration in bronchial biopsies.

Results

In total, 27/55 patients (49%) had OSA diagnosed by overnight polygraphy. Despite a moderate increase in apnoea-hypopnoea index (AHI; 14.2±1.6 event/h [535]), the proportion of sputum neutrophils was higher and that of macrophages lower in OSA than non-OSA patients, with higher levels of interleukin 8 and matrix metalloproteinase 9. The RBM was significantly thinner in OSA than non-OSA patients (5.8±0.4 vs. 7.8±0.4 μm, p<0.05). RBM thickness and OSA severity assessed by the AHI were negatively correlated (rho = -0.65, p<0.05). OSA and non-OSA patients did not differ in age, sex, BMI, lung function, asthma control findings or treatment.

Conclusion

Mild OSA in patients with severe asthma is associated with increased proportion of neutrophils in sputum and changes in airway remodelling.  相似文献   

11.
BackgroundAntiretroviral treatments decrease HIV mother-to-child transmission through pre/post exposure prophylaxis and reduction of maternal viral load. We modeled in-utero and intra-partum HIV transmissions to investigate the preventive role of various antiretroviral treatments interventions.MethodsWe analysed data from 3,759 women-infant pairs enrolled in 3 randomized clinical trials evaluating (1) zidovudine monotherapy, (2) zidovudine plus perinatal single-dose nevirapine or (3) zidovudine plus lopinavir/ritonavir for the prevention of mother-to-child transmission of HIV in Thailand. All infants were formula-fed. Non-linear mixed effect modeling was used to express the viral load evolution under antiretroviral treatments and the probability of transmission.ResultsMedian viral load was 4 log10 copies/mL (Interquartile range: 3.36–4.56) before antiretroviral treatments initiation. An Emax model described the viral load time-course during pregnancy. Half of the maximum effect of zidovudine (28% decrease) and lopinavir/ritonavir (72% decrease) were achieved after 98 and 12 days, respectively. Adjusted on viral load at baseline (Odds ratio = 1.50 [95% confidence interval: 1.34, 1.68] per log10 copies/mL increment), antiretroviral treatments duration (OR = 0.80 [0.75, 0.84] per week increment) but not the nature of antiretroviral treatments were associated with in-utero transmission. Adjusted on gestational age at delivery (<37 weeks, OR = 2.37 [1.37, 4.10]), baseline CD4 (Odds ratio = 0.79 [0.72, 0.88] per 100 cells/mm3 increment) and predicted viral load at delivery (OR = 1.47 [1.25, 1.64] per log10 copies/mL increment), single-dose nevirapine considerably reduced intra-partum transmission (OR = 0.32 [0.2, 0.51]).ConclusionThese models determined the respective contributions of various antiretroviral strategies on prevention of mother-to-child transmission. This can help predict the efficacy of new antiretroviral treatments and/or prevention of mother-to-child transmission strategies particularly for women with no or late antenatal care who are at high risk of transmitting HIV to their offspring.

Trial Registration

This analysis is based on secondary data obtained from three clinical trials. ClinicalTrials.gov. NCT00386230, NCT00398684, NCT00409591.  相似文献   

12.
We present VISual Plotting Interface for Genetics (visPIG; http://vispig.icr.ac.uk), a web application to produce multi-track, multi-scale, multi-region plots of genetic data. visPIG has been designed to allow users not well versed with mathematical software packages and/or programming languages such as R [1], Matlab®, Python, etc., to integrate data from multiple sources for interpretation and to easily create publication-ready figures. While web tools such as the UCSC Genome Browser [2] or the WashU Epigenome Browser [3] allow custom data uploads, such tools are primarily designed for data exploration. This is also true for the desktop-run Integrative Genomics Viewer (IGV) [4],[5]. Other locally run data visualisation software such as Circos [6] require significant computer skills of the user. The visPIG web application is a menu-based interface that allows users to upload custom data tracks and set track-specific parameters. Figures can be downloaded as PDF or PNG files. For sensitive data, the underlying R [1] code can also be downloaded and run locally. visPIG is multi-track: it can display many different data types (e.g association, functional annotation, intensity, interaction, heat map data,…). It also allows annotation of genes and other custom features in the plotted region(s). Data tracks can be plotted individually or on a single figure. visPIG is multi-region: it supports plotting multiple regions, be they kilo- or megabases apart or even on different chromosomes. Finally, visPIG is multi-scale: a sub-region of particular interest can be ''zoomed'' in. We describe the various features of visPIG and illustrate its utility with examples. visPIG is freely available through http://vispig.icr.ac.uk under a GNU General Public License (GPLv3).  相似文献   

13.

Background

Group A Rotaviruses are a major etiologic agent of gastroenteritis in infants and young children (<5 years) worldwide. Although rotavirus vaccines have been successfully administered in many countries, in India the introduction of rotavirus vaccine in national immunization program was approved in 2014. Since high disease burden and large number of genetic variants have been reported from low income countries including India, monitoring of rotavirus was initiated prior to implementation of the vaccine in the region.

Methods

A total number of 3,582 stool samples were collected from an urban slum community in Kolkata, among which 1,568 samples were obtained from children of ≤5 years of age, with moderate to severe diarrhoea and 2,014 samples were collected from age-sex matched healthy neighbourhood controls. Rotavirus positive samples were typed by multiplex semi-nested PCR and nucleotide sequencing. Circulating strains were phylogenetically analyzed.

Results

Among 1,568 children with diarrhoea, 395 (25.2%), and among 2,014 asymptomatic children, 42 (2%) were rotavirus positive. G1P[8] was identified as the most common strain (32%) followed by G9P[8] (16.9%), G2P[4] (13.5%) and G9P[4] (10.75%). G12 strains with combinations of P[4], P[6] and P[8] comprised 11.9% of total positive strains. The rest (<10%) were rare and uncommon strains like G1P[4], G1P[6], G2P[8] and animal-like strains G4P[6], G6P[14] and G11P[25]. The 42 rotavirus positive samples from asymptomatic children revealed common genotypes like G1, G2 and G9.

Conclusion

This community based case-control study showed increased predominance of genotype G9 in Kolkata. It also confirmed co-circulation of a large number of genetic variants in the community. Asymptomatic rotavirus positive children though low in number can also be a source of dispersal of infection in the community. This study provides background information to the policy makers for implementation of rotavirus vaccines in this region.  相似文献   

14.
BackgroundDuring the Coronavirus Disease 2019 (COVID-19) pandemic, the number of consultations and diagnoses in primary care and referrals to specialist care declined substantially compared to prepandemic levels. Beyond deferral of elective non-COVID-19 care by healthcare providers, it is unclear to what extent healthcare avoidance by community-dwelling individuals contributed to this decline in routine healthcare utilisation. Moreover, it is uncertain which specific symptoms were left unheeded by patients and which determinants predispose to healthcare avoidance in the general population. In this cross-sectional study, we assessed prevalence of healthcare avoidance during the pandemic from a patient perspective, including symptoms that were left unheeded, as well as determinants of healthcare avoidance.Methods and findingsOn April 20, 2020, a paper COVID-19 survey addressing healthcare utilisation, socioeconomic factors, mental and physical health, medication use, and COVID-19–specific symptoms was sent out to 8,732 participants from the population-based Rotterdam Study (response rate 73%). All questionnaires were returned before July 10, 2020. By hand, prevalence of healthcare avoidance was subsequently verified through free text analysis of medical records of general practitioners. Odds ratios (ORs) for avoidance were determined using logistic regression models, adjusted for age, sex, and history of chronic diseases. We found that 1,142 of 5,656 included participants (20.2%) reported having avoided healthcare. Of those, 414 participants (36.3%) reported symptoms that potentially warranted urgent evaluation, including limb weakness (13.6%), palpitations (10.8%), and chest pain (10.2%). Determinants related to avoidance were older age (adjusted OR 1.14 [95% confidence interval (CI) 1.08 to 1.21]), female sex (1.58 [1.38 to 1.82]), low educational level (primary education versus higher vocational/university 1.21 [1.01 to 1.46), poor self-appreciated health (per level decrease 2.00 [1.80 to 2.22]), unemployment (versus employed 2.29 [1.54 to 3.39]), smoking (1.34 [1.08 to 1.65]), concern about contracting COVID-19 (per level increase 1.28 [1.19 to 1.38]) and symptoms of depression (per point increase 1.13 [1.11 to 1.14]) and anxiety (per point increase 1.16 [1.14 to 1.18]). Study limitations included uncertainty about (perceived) severity of the reported symptoms and potentially limited generalisability given the ethnically homogeneous study population.ConclusionsIn this population-based cross-sectional study, 1 in 5 individuals avoided healthcare during lockdown in the COVID-19 pandemic, often for potentially urgent symptoms. Healthcare avoidance was strongly associated with female sex, fragile self-appreciated health, and high levels of depression and anxiety. These results emphasise the need for targeted public education urging these vulnerable patients to timely seek medical care for their symptoms to mitigate major health consequences.

Marije J. Splinter and colleagues assess the prevalence of healthcare avoidance during the COIVD-19 pandemic and investigate related determinants  相似文献   

15.
Heat capacity (HC) has an important role in the temperature regulation process, particularly in dealing with the heat load. The actual measurement of the body HC is complicated and is generally estimated by body-composition-specific data. This study compared the previously known HC estimating equations and sought how to define HC using simple anthropometric indices such as weight and body surface area (BSA) in the Korean population. Six hundred participants were randomly selected from a pool of 902 healthy volunteers aged 20 to 70 years for the training set. The remaining 302 participants were used for the test set. Body composition analysis using multi-frequency bioelectrical impedance analysis was used to access body components including body fat, water, protein, and mineral mass. Four different HCs were calculated and compared using a weight-based HC (HC_Eq1), two HCs estimated from fat and fat-free mass (HC_Eq2 and HC_Eq3), and an HC calculated from fat, protein, water, and mineral mass (HC_Eq4). HC_Eq1 generally produced a larger HC than the other HC equations and had a poorer correlation with the other HC equations. HC equations using body composition data were well-correlated to each other. If HC estimated with HC_Eq4 was regarded as a standard, interestingly, the BSA and weight independently contributed to the variation of HC. The model composed of weight, BSA, and gender was able to predict more than a 99% variation of HC_Eq4. Validation analysis on the test set showed a very high satisfactory level of the predictive model. In conclusion, our results suggest that gender, BSA, and weight are the independent factors for calculating HC. For the first time, a predictive equation based on anthropometry data was developed and this equation could be useful for estimating HC in the general Korean population without body-composition measurement.  相似文献   

16.

Motivation

Array-CGH can be used to determine DNA copy number, imbalances in which are a fundamental factor in the genesis and progression of tumors. The discovery of classes with similar patterns of array-CGH profiles therefore adds to our understanding of cancer and the treatment of patients. Various input data representations for array-CGH, dissimilarity measures between tumor samples and clustering algorithms may be used for this purpose. The choice between procedures is often difficult. An evaluation procedure is therefore required to select the best class discovery method (combination of one input data representation, one dissimilarity measure and one clustering algorithm) for array-CGH. Robustness of the resulting classes is a common requirement, but no stability-based comparison of class discovery methods for array-CGH profiles has ever been reported.

Results

We applied several class discovery methods and evaluated the stability of their solutions, with a modified version of Bertoni''s -based test [1]. Our version relaxes the assumption of independency required by original Bertoni''s -based test. We conclude that Minimal Regions of alteration (a concept introduced by [2]) for input data representation, sim [3] or agree [4] for dissimilarity measure and the use of average group distance in the clustering algorithm produce the most robust classes of array-CGH profiles.

Availability

The software is available from http://bioinfo.curie.fr/projects/cgh-clustering. It has also been partly integrated into "Visualization and analysis of array-CGH"(VAMP)[5]. The data sets used are publicly available from ACTuDB [6].  相似文献   

17.
Live-attenuated oral rotavirus (RV) vaccines have lower efficacy in low income countries, and additionally are associated with a rare but severe adverse event, intussusception. We have been pursuing the development of an inactivated rotavirus vaccine (IRV) using the human rotavirus strain CDC-9 (G1P[8]) through parenteral immunization and previously demonstrated dose sparing and enhanced immunogenicity of intradermal (ID) unadjuvanted IRV using a coated microneedle patch in comparison with intramuscular (IM) administration in mice. The aim of this study was to evaluate the immune response and protection against RV infection and diarrhea conferred by the administration of the ID unadjuvanted IRV using the microneedle device MicronJet600® in neonatal gnotobiotic (Gn) piglets challenged with virulent Wa G1P[8] human RV. Three doses of 5 μg IRV when administered intradermally and 5 μg IRV formulated with aluminum hydroxide [Al(OH)3] when administered intramuscularly induced comparable rotavirus-specific antibody titers of IgA, IgG, IgG avidity index and neutralizing activity in sera of neonatal piglets. Both IRV vaccination regimens protected against RV antigen shedding in stools, and reduced the cumulative diarrhea scores in the piglets. This study demonstrated that the ID and IM administrations of IRV are immunogenic and protective against RV-induced diarrhea in neonatal piglets. Our findings highlight the potential value of an adjuvant sparing effect of the IRV ID delivery route.  相似文献   

18.

Background

Understanding the dynamics of the human range expansion across northeastern Eurasia during the late Pleistocene is central to establishing empirical temporal constraints on the colonization of the Americas [1]. Opinions vary widely on how and when the Americas were colonized, with advocates supporting either a pre-[2] or post-[1], [3], [4], [5], [6] last glacial maximum (LGM) colonization, via either a land bridge across Beringia [3], [4], [5], a sea-faring Pacific Rim coastal route [1], [3], a trans-Arctic route [4], or a trans-Atlantic oceanic route [5]. Here we analyze a large sample of radiocarbon dates from the northeast Eurasian Upper Paleolithic to identify the origin of this expansion, and estimate the velocity of colonization wave as it moved across northern Eurasia and into the Americas.

Methodology/Principal Findings

We use diffusion models [6], [7] to quantify these dynamics. Our results show the expansion originated in the Altai region of southern Siberia ∼46kBP , and from there expanded across northern Eurasia at an average velocity of 0.16 km per year. However, the movement of the colonizing wave was not continuous but underwent three distinct phases: 1) an initial expansion from 47-32k calBP; 2) a hiatus from ∼32-16k calBP, and 3) a second expansion after the LGM ∼16k calBP. These results provide archaeological support for the recently proposed three-stage model of the colonization of the Americas [8], [9]. Our results falsify the hypothesis of a pre-LGM terrestrial colonization of the Americas and we discuss the importance of these empirical results in the light of alternative models.

Conclusions/Significance

Our results demonstrate that the radiocarbon record of Upper Paleolithic northeastern Eurasia supports a post-LGM terrestrial colonization of the Americas falsifying the proposed pre-LGM terrestrial colonization of the Americas. We show that this expansion was not a simple process, but proceeded in three phases, consistent with genetic data, largely in response to the variable climatic conditions of late Pleistocene northeast Eurasia. Further, the constraints imposed by the spatiotemporal gradient in the empirical radiocarbon record across this entire region suggests that North America cannot have been colonized much before the existing Clovis radiocarbon record suggests.  相似文献   

19.
The contention and treatment of Mycobacterium tuberculosis and other bacteria that cause infectious diseases require the use of new type of antibiotics. Pandinin 2 (Pin2) is a scorpion venom antimicrobial peptide highly hemolytic that has a central proline residue. This residue forms a structural “kink” linked to its pore-forming activity towards human erythrocytes. In this work, the residue Pro14 of Pin2 was both substituted and flanked using glycine residues (P14G and P14GPG) based on the low hemolytic activities of antimicrobial peptides with structural motifs Gly and GlyProGly such as magainin 2 and ponericin G1, respectively. The two Pin2 variants showed antimicrobial activity against E. coli, S. aureus, and M. tuberculosis. However, Pin2 [GPG] was less hemolytic (30%) than that of Pin2 [G] variant. In addition, based on the primary structure of Pin2 [G] and Pin2 [GPG], two short peptide variants were designed and chemically synthesized keeping attention to their physicochemical properties such as hydrophobicity and propensity to adopt alpha-helical conformations. The aim to design these two short antimicrobial peptides was to avoid the drawback cost associated to the synthesis of peptides with large sequences. The short Pin2 variants named Pin2 [14] and Pin2 [17] showed antibiotic activity against E. coli and M. tuberculosis. Besides, Pin2 [14] presented only 25% of hemolysis toward human erythrocytes at concentrations as high as 100 µM, while the peptide Pin2 [17] did not show any hemolytic effect at the same concentration. Furthermore, these short antimicrobial peptides had better activity at molar concentrations against multidrug resistance M. tuberculosis than that of the conventional antibiotics ethambutol, isoniazid and rifampicin. Therefore, Pin2 [14] and Pin2 [17] have the potential to be used as an alternative antibiotics and anti-tuberculosis agents with reduced hemolytic effects.  相似文献   

20.
Modern computational neuroscience employs diverse software tools and multidisciplinary expertise to analyze heterogeneous brain data. The classical problems of gathering meaningful data, fitting specific models, and discovering appropriate analysis and visualization tools give way to a new class of computational challenges—management of large and incongruous data, integration and interoperability of computational resources, and data provenance. We designed, implemented and validated a new paradigm for addressing these challenges in the neuroimaging field. Our solution is based on the LONI Pipeline environment [3], [4], a graphical workflow environment for constructing and executing complex data processing protocols. We developed study-design, database and visual language programming functionalities within the LONI Pipeline that enable the construction of complete, elaborate and robust graphical workflows for analyzing neuroimaging and other data. These workflows facilitate open sharing and communication of data and metadata, concrete processing protocols, result validation, and study replication among different investigators and research groups. The LONI Pipeline features include distributed grid-enabled infrastructure, virtualized execution environment, efficient integration, data provenance, validation and distribution of new computational tools, automated data format conversion, and an intuitive graphical user interface. We demonstrate the new LONI Pipeline features using large scale neuroimaging studies based on data from the International Consortium for Brain Mapping [5] and the Alzheimer''s Disease Neuroimaging Initiative [6]. User guides, forums, instructions and downloads of the LONI Pipeline environment are available at http://pipeline.loni.ucla.edu.  相似文献   

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