***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background : Social support can reduce cardiovascular responses to an acute stressor . However , prior clinical research suggests that defensive individuals may react negatively to social support . Purpose : This experiment examined whether emotional support provided during a speech stressor would escalate rather than decrease blood pressure ( BP ) reactivity among defensive individuals . Methods : After completing personality measures , 176 female undergraduates were r and omly assigned to give a speech in 1 of 3 social conditions : alone , or with a neutral or supportive confederate present . Mean arterial BP was assessed at baseline , immediately before , and during and after the stressor . Results : In the supportive condition , defensiveness predicted higher BP reactivity during anticipation ( ß = .35,p = .04 ) and delivery of the speech ( ß = .32 , p = .03 ) , and longer recovery to baseline BP levels ( ß = .35,p = .01 ) . In the absence of support ( i.e. , alone and neutral conditions ) , defensiveness was not associated with BP reactivity . Defensiveness also predicted greater dissociation between subjective stress and BP responses ( ß = .35 , p = .05 ) , but only in the supportive condition . Conclusions : According to results , the provision of social support during stressors does not benefit defensive individuals ’ BP reactivity but has the opposite effect Research suggests that females seek out , prefer , and are more receptive to emotional support ( encouragement ) , and that males seek out , prefer , and are more receptive to instrumental support ( problem-solving ) . Thus , we hypothesized that boys would show lower blood pressure ( BP ) reactivity in response to instrumental than emotional or no support , and that girls would show lower BP reactivity in response to emotional than instrumental or no support .  Forty-eight healthy African-American adolescents ( 50 % males ) participated in a role play conflict task  and were  r and omized to receive either emotional , instrumental , or no support ( presence only ) from a confederate . Boys showed lower systolic blood pressure ( SBP ) reactivity in the instrumental than in the emotional or no support conditions and lower recovery SBP as compared to boys in the emotional or no support conditions . A similar pattern of results was demonstrated for diastolic blood pressure ( DBP ) reactivity .  Girls , however , did not demonstrate lower BP reactivity in response to emotional as compared to instrumental support . These findings suggest that instrumental and emotional support differentially influence cardiovascular ( CV ) reactivity in African-American boys versus girls We tested whether the presence of a stranger  reduces cardiovascular responses during stressful tasks if the evaluation potential of the stranger is minimized and whether cardiovascular responses are affected by the quality of support in a friendship . Undergraduate women performed stressful tasks in one of three conditions :  Alone , with a same-sex Stranger , or with a same-sex best Friend .  The stranger and friend could not hear participants ' responses . Alone women had the greatest increases in SBP and HR while women in the Stranger and Friend conditions did not differ in their responses . In the Friend condition , HR responses were smallest in women who were highly satisfied with the support that they generally received from their friend . We conclude that the presence of a nonevaluative friend or stranger can reduce cardiovascular responses and that the quality of supportive ties modulates the impact of those ties on responses to stress Previous research suggests that in contrast to invisible social support , visible social support produces exaggerated negative emotional responses . Drawing on work by Bolger and colleagues , this study disentangled social support visibility from negative social evaluation in an examination of the effects of social support on negative emotions and cardiovascular responses . As part of an anticipatory speech task , 73 female participants were r and omly assigned to receive no social support , invisible social support , non-confounded visible social support or visible social support  as delivered in a 2007 study by Bolger and Amarel . Twelve readings , each for systolic blood pressure , diastolic blood pressure and heart rate were taken at 5-min intervals throughout the periods of baseline , reactivity and recovery . Cardiovascular outcomes were tested by incorporating a series of theoretically driven planned contrasts into tests of stress reactivity conducted through piecewise growth curve modelling . Linear and quadratic trends established cardiovascular reactivity to the task . Further , in comparison to the control and replication conditions , the non-confounded visible and invisible social support conditions attenuated cardiovascular reactivity over time . Pre- and post-speech negative emotional responses were not affected by the social support manipulations . These results suggest that appropriately delivered visible social support may be as beneficial as invisible social support The authors tested the hypothesis that the response-attenuating effects of affiliation under stress are limited to conditions that involve high social threat . Ninety-six young adult women were exposed to st and ardized psychological challenges  in one of four conditions that involved two levels of social affiliation ( alone or accompanied by a close friend ) and two levels of social threat ( variations in the social behavior and perceived status of the experimenter ) . Social affiliation was associated with attenuated blood pressure responses to the challenges but only under conditions of high social threat . Affiliation was not associated with differences in self-reported emotional response to the challenges nor with alterations in cognitive task appraisal . Exploratory analyses suggested that some of these effects were stronger in hostile or socially avoidant individuals . Implication s of these findings for interpreting the literature on social support and cardiovascular reactivity , and for underst and ing the potential role of social support in reducing stress-related disease pathogenesis , are discussed Recent scientific work has established both a theoretical basis and strong empirical evidence for a causal impact of social relationships on health . Prospect i ve studies , which control for baseline health status , consistently show increased risk of death among persons with a low quantity , and sometimes low quality , of social relationships . Experimental and quasi-experimental studies of humans and animals also suggest that social isolation is a major risk factor for mortality from widely varying causes . The mechanisms through which social relationships affect health and the factors that promote or inhibit the development and maintenance of social relationships remain to be explored Objective : To examine the effect of a brief laboratory stressor and social support before the stressor on cardiovascular and cortisol responses , and skin barrier recovery after skin disruption . Methods : Eighty-five healthy participants ( mean age 22.9 ± 4.4 years ) underwent a “ tape-stripping ” procedure that disrupts normal skin barrier function , and were r and omly assigned to a No Stress ( reading task ) , Stress ( Trier Social Stress Test ) , or Stress + Social Support condition ( support from a confederate before the stressor )  . Skin barrier recovery was assessed by measuring transepidermal water loss from up to 2 hours after skin disruption . Results : Compared with the No Stress condition , the stressor delayed skin barrier recovery by 10 % at 2 hours after skin disruption ( effect size , r = .29 ) , and increased anxiety ( r = .24 ) , negative affect ( r = .22 ) , cardiovascular activity ( r values from .4–.6 ) , and among male participants , cortisol levels ( r = .40 ) . Social support did not influence psychological or physiological responses or skin barrier recovery . Larger physiological responses to the tasks did not predict slower skin barrier recovery . Instead , larger systolic blood pressure responses predicted faster skin barrier recovery ( r = .26 ) . Conclusions : This study replicated the effects of short-term laboratory stressors on skin barrier recovery , further establishing the relevance of skin barrier recovery for future research . The support manipulation did not influence physiological responses or skin barrier recovery , suggesting that future research on social support , physiology , and objective health outcomes should focus on naturalistic social interactions , relationships , and stressors . AUCI = area under the curve with respect to increase ; BMI = body mass index ; DBP = diastolic blood pressure ; GCRC = General Clinical Research Center ; HR = heart rate ; MAP = mean arterial pressure ; SBP = systolic blood pressure ; TSST = Trier Social Stress Test ; TEWL = transepidermal water loss OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity This study examined whether highly cynical individuals benefit less from social support during an acute stressor than individuals low in cynicism . College students ( 52 men , 52 women ) performed a stressful speech task alone or in the presence of a supportive confederate . There was an interactive effect of social support and cynicism on cardiovascular reactivity : Low cynicism participants who received support has smaller increases in blood pressure during the speech than low cynicism participants without support and high cynicism participants with or without support . Participants ' psychological stress appeared to mediate the main effects of support on blood pressure reactivity , but not the Support x Cynicism interaction . Results suggest that cynical attitudes may undermine the stress buffering potential of interpersonal support In addition to actual social interactions , internal representations of supportive ties could affect mechanisms linking relationships and health . Undergraduates ( 41 men , 41 women ) wrote about supportive ties or casual acquaintances . Supportive ties were rated as warmer and less controlling than acquaintances , and writing about them evoked reductions in negative affect , especially for low-hostile participants . Compared with the acquaintance condition , the supportive tie condition result ed in reduced heart rate and blood pressure response during a subsequent speech stressor . Among women , the supportive tie condition reduced blood pressure response among low- but not among high-hostile participants . Hence , mental activation of supportive ties altered effects of laboratory stress and might be relevant to the effects of social relations on health This study examines the possibility that social support operates as a moderator of  cardiovascular reactivity in women . Two models by which social support may operate were examined : the direct effects and buffering models . Twenty-six subjects were exposed to four conditions while playing a video game : two levels of stress ( low , high ) and two levels of social support ( alone , together ) .  Blood pressure and heart rate were monitored continuously . Ratings of stress were obtained for each condition . Results indicated that the support manipulation produced significant main effects for diastolic blood pressure and stress ratings , with lower diastolic blood pressure and ratings observed in the " together " condition , and that the interaction between support and stress produced lower reactivity for the cardiovascular measures in the high stress ( but not the low stress ) condition . No interaction was found for the stress ratings . We conclude that the results provide support for both the buffering and direct effects models . Implication s concerning the ( within-subjects ) design of the study and the stress ratings are discussed This study examined the joint and independent effects of experimentally manipulated social context s and individual differences in hostility and perceived social support on physiological responses to a social stressor , while illustrating the use of the interpersonal circumplex for integrative social psychophysiological research . Undergraduate women completed a speech task in a supportive , neutral , or provoking context and completed measures of hostility and perceived social support . The provoking context evoked the largest blood pressure and heart rate ( HR ) responses , followed by the neutral and the supportive context . Social context also influenced HR and electrodermal reactivity during task preparation . Hostility elicited higher systolic blood pressure ( SBP ) reactivity during preparation , speech , and recovery . Perceived social support interacted with context to affect SBP and HR during speech and preparation . The roles of interpersonal characteristics and context s in the physiological stress response and the utility of interpersonal methods in study ing these associations are discussed The influence of the availability of social support on cardiovascular reactivity to acute psychological stress was examined . Twenty-eight men and twenty-one women performed a speech task either in a support availability or no support availability condition while measures of systolic blood pressure ( SBP ) , diastolic blood pressure ( DBP ) , and heart rate ( HR ) were assessed . Consistent with past research , the speech stressor was associated with significant increases in SBP , DBP , and HR . More important , the availability of social support moderated cardiovascular reactivity to the acute stressor : individuals in the support availability condition were characterized by lower SBP and DBP reactivity to the acute stressor compared to individuals in the no support availability condition . These data suggest that simply having potential access to support is sufficient to foster adaptation to stress in the absence of en 
    Output:
    
When participants were in more engaging conditions , social support decreased CVR relative to no support .
When participants were in less engaging conditions , social support did not have a significant effect on CVR .
Provide an alternative way to explain the ways social support affects cardiac health