980 resultados para Triggers


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Rising atmospheric CO2 often triggers the production of plant phenolics, including many that serve as herbivore deterrents, digestion reducers, antimicrobials, or ultraviolet sunscreens. Such responses are predicted by popular models of plant defense, especially resource availability models which link carbon availability to phenolic biosynthesis. CO2 availability is also increasing in the oceans, where anthropogenic emissions cause ocean acidification, decreasing seawater pH and shifting the carbonate system towards further CO2 enrichment. Such conditions tend to increase seagrass productivity but may also increase rates of grazing on these marine plants. Here we show that high CO2 / low pH conditions of OA decrease, rather than increase, concentrations of phenolic protective substances in seagrasses and eurysaline marine plants. We observed a loss of simple and polymeric phenolics in the seagrass Cymodocea nodosa near a volcanic CO2 vent on the Island of Vulcano, Italy, where pH values decreased from 8.1 to 7.3 and pCO2 concentrations increased ten-fold. We observed similar responses in two estuarine species, Ruppia maritima and Potamogeton perfoliatus, in in situ Free-Ocean-Carbon-Enrichment experiments conducted in tributaries of the Chesapeake Bay, USA. These responses are strikingly different than those exhibited by terrestrial plants. The loss of phenolic substances may explain the higher-than-usual rates of grazing observed near undersea CO2 vents and suggests that ocean acidification may alter coastal carbon fluxes by affecting rates of decomposition, grazing, and disease. Our observations temper recent predictions that seagrasses would necessarily be "winners" in a high CO2 world.

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Natural radionuclides and man-made 137Cs were analyzed in five short sediment cores taken in northern part of the Gulf of Eilat (Gulf of Aqaba) in order to provide information on sedimentation and mixing rates and sediment sources. The maximum estimates of sedimentation rates based on excess 210Pb were found to vary between 0.105 ± 0.020 and 0.35 ± 0.23 cm · year**-1. Even the lowest estimates are significantly higher than those expected from dust deposition, suggesting other sources and processes being responsible for most of the allochthonous material accumulation, including periodical floods following heavy rain events, internal erosion or triggers, like earthquakes. In 137Cs depth profiles no 1963 related nuclear weapon test maxima were found; instead, the activities decrease monotonically, suggesting that a major process leading to radionuclides' depth distribution might be mixing. The mixing rates calculated from 137Cs, excess 210Pb and excess 228Th reach values up to 2.18 ± 0.69 cm**2 · year**-1.

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The walls of blood vessels are lined with a single-cell layer of endothelial cells. As blood flows through the arteries, a frictional force known as shear stress is sensed by mechanosensitive structures on the endothelium. Short and long term changes in shear stress can have a significant influence on the regulation of endothelial function. Acutely, shear stress triggers a pathway that culminates in the release of vasodilatory molecules from the endothelium and subsequent vasodilation of the artery. This endothelial response is known as flow mediated dilation (FMD). FMD is used as an index of endothelial function and is commonly assessed using reactive hyperemia (RH)-FMD, a method which elicits a large, short lived increase in shear stress following the release of a brief (5 min) forearm occlusion. A recent study found that a short term exposure (30 min) to a sustained elevation in shear stress potentiates subsequent RH-FMD. FMD can also result from a more prolonged, sustained increase in shear stress elicited by handgrip exercise (HGEX-FMD). There is evidence to suggest that interventions and conditions impact FMD resulting from sustained and transient shear stress stimuli differently, indicating that HGEX-FMD and RH-FMD provide different information about endothelial function. It is unknown whether HGEX-FMD is improved by short term exposure to shear stress. Understanding how exercise induced FMD is regulated is important because it contributes to blood flow responses during exercise. The study purpose was therefore to assess the impact of a handgrip exercise (intervention) induced sustained elevation in shear stress on subsequent brachial artery (BA) HGEX-FMD. Twenty healthy male participants (22±3yrs) preformed a 30-minute HGEX intervention on two experimental days. BA-FMD was assessed using either an RH or HGEX shear stress stimulus at 3 time points: pre-intervention, 10 min post and 60 min post. FMD and shear stress magnitude were determined via ultrasound. Both HGEX and RH-FMD increased significantly from pre-intervention to 10 min-post (p<0.01). These findings indicate that FMD stimulated by exercise induced increases in shear stress is potentiated by short term shear stress exposure. These findings advance our understanding regarding the regulation of endothelial function by shear stress.

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Activation triggers the exchange of subunits in Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), an oligomeric enzyme that is critical for learning, memory, and cardiac function. The mechanism by which subunit exchange occurs remains elusive. We show that the human CaMKII holoenzyme exists in dodecameric and tetradecameric forms, and that the calmodulin (CaM)-binding element of CaMKII can bind to the hub of the holoenzyme and destabilize it to release dimers. The structures of CaMKII from two distantly diverged organisms suggest that the CaM-binding element of activated CaMKII acts as a wedge by docking at intersubunit interfaces in the hub. This converts the hub into a spiral form that can release or gain CaMKII dimers. Our data reveal a three-way competition for the CaM-binding element, whereby phosphorylation biases it towards the hub interface, away from the kinase domain and calmodulin, thus unlocking the ability of activated CaMKII holoenzymes to exchange dimers with unactivated ones.

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Activation triggers the exchange of subunits in Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), an oligomeric enzyme that is critical for learning, memory, and cardiac function. The mechanism by which subunit exchange occurs remains elusive. We show that the human CaMKII holoenzyme exists in dodecameric and tetradecameric forms, and that the calmodulin (CaM)-binding element of CaMKII can bind to the hub of the holoenzyme and destabilize it to release dimers. The structures of CaMKII from two distantly diverged organisms suggest that the CaM-binding element of activated CaMKII acts as a wedge by docking at intersubunit interfaces in the hub. This converts the hub into a spiral form that can release or gain CaMKII dimers. Our data reveal a three-way competition for the CaM-binding element, whereby phosphorylation biases it towards the hub interface, away from the kinase domain and calmodulin, thus unlocking the ability of activated CaMKII holoenzymes to exchange dimers with unactivated ones.

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De Hoofdvraag van dit onderzoek is: Is er een relatie tussen de lever of control Interactive control en het vervullen van de controllerrol business partner? Dit onderzoek is gebaseerd op de dataset verkregen uit de controllerenquête 2013, uitgevoerd in opdracht van de Open Universiteit (Bork & van der Wal, 2014). Vanuit het literatuuronderzoek is het duidelijk: de rol business partner is een zeer gewenste rol voor controllers. Daarnaast is er in de literatuur een verband te vinden tussen de rol business partner en de lever of control Interactive control. De factor- en clusteranalyse zoals beschreven door Bork & van der Wal (2014), resulteerde in de identificatie van twee type controllers. In dit uitgebreide onderzoek is TYPE II geïdentificeerd als business partner, omdat hij/zij activiteitencombinaties uitvoert die gerelateerd zijn aan strategie, analyseren, het management ondersteunen in besluitvorming, advisering, change management en de organisatie vertegenwoordigen. 36% van de populatie van aan Nederlandse Universiteiten afgestudeerde controllers die ook werkzaam zijn als controller vervullen een rol grotendeels gelijk aan de rol business partner. De vervulling van de rol (TYPE II) is niet puur business partner. Vervaardigen en organiseren van rapportagestromen zijn ook activiteiten die uitgevoerd worden door TYPE II. Daarnaast voert TYPE I activiteiten als change en risk management uit, volgens de definitie zou de business partner deze activiteiten uit moeten voeren. De rol business partner wordt uitgevoerd, maar nog niet in de optimale vorm zoals aangegeven in de theorie. De logistische regressieanalyse op de dataset laat zien dat geen van de levers of control een significante trigger is voor het uitvoeren van een van de twee types controllerrollen (Bork & van der Wal, 2014). Dit verdiepende onderzoek concentreert zich op de relatie tussen de lever of control Interactive control en de zes activiteitencombinaties (factoren) in plaats van de twee clusters (TYPE I & II). De statistische analyses bevestigen de uitkomsten het onderzoek van Bork & van der Wal (2014). Er is geen significantie tussen Interactive control en de factoren die behoren bij de business partner rol. De hoofdvraag moet ontkennend beantwoord worden, er is geen relatie tussen de lever of control Interactive control en de controllerrol business partner. Een paar beperkingen van het onderzoek richten zich op de vragenlijst over de levers of control: is het de juiste vragenlijst voor dit onderzoek en meet deze vragenlijst de levers of control van controllers? Vervolg onderzoek kan zich richten op bovenstaande beperking. Daarnaast zijn er uit het onderzoek van Bork & van der Wal (2014) triggers naar voren gekomen die verder onderzocht kunnen worden.

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Which 'actor' takes the management accountant role as an extravert business partner? Does a relation between the personal trait Extraversion and fulfilling a management accountant role as a business partner exist? Open Universiteit Nederland End thesis MSc Management, Accounting & Finance Support 1: Prof. dr. A.C.N. van de Ven RA Support 2: dr. P.C.M. Claes Examinator: dr. P. Kamminga Date of approval: September 3, 2014 student: P.R. van der Wal (studentnumber 839104017 email petervanderwal2003@yahoo.com The main question of this research is: Does a relation between the personal trait Extraversion and fulfilling a management accountant role as a business partner exist? This research is based on the dataset obtained by the controller survey 2013, executed in commission of the 'Open Universiteit' (Bork & van der Wal, 2014). From the literature review it is clear: among other management accountant roles we need business partners. And there is a relation between the personal trait Extraversion and fulfilling the role as business partner. At the same time a lack of necessary personal traits for this role has been noticed, among which is Extraversion. The factor- and cluster analyses reported by Bork & van der Wal (2014) resulted in the identification of two types of management accountant roles. In this extended research TYPE II is identified as a business partner because (s)he practices activity-combinations which are related to strategy, analyzing, supporting management in decision making, advisory, change-agency and representing the organization. 36% of the population of Dutch management accountants with a master degree (or similar) meet with the role of the business partner. Although the fulfillment of the role (TYPE II) is not purely business partnering. E.g. reporting and scorekeeping are still activities executed by TYPE II and it is not clear to what extent. Apart from that, role TYPE I executes change management and risk-management activities, which are (according to the definition) activities that belong to the business partner. The role as business partner is practiced but not that optimal as defined in theory. The logistic regression analyses on the survey-data show that Extraversion among three other triggers is significant for the prediction of the fulfillment of the management accountant role (Bork & van der Wal, 2014). A more extravert personal trait predicts a preference for TYPE II, which relates to the business partner. This 'in depth research' concentrated on the relation between the Big Five personal traits and the six activity-combinations (factors) instead of on the two clusters (I and II). The statistic analyses confirm the predicting influence of Extraversion on the business partner role. Although, except for one factor, no extra significance has been found in this additional research. The essential question can be confirmed positively: the management accountant role business partner exists in practice, some management accountants are more extravert then others, and there is a positive relation between extraversion and fulfilling the business partner role. Some formulated research limitations are related to the statistical weakness of some prediction outcomes and to interpretation differences that might occur. Further research can e.g. concentrate on the other personal traits and the significance for role-differentiation in education programs. The management accountant survey 2013 Management accountant roles in 2013 in the Netherlands Open Universiteit Nederland End thesis MSc Management, Accounting & Finance Support 1: Prof. dr. A.C.N. van de Ven RA Support 2: dr. P.C.M. Claes Examinator: dr. P. Kamminga Date of approval: September 3, 2014 student: P.R. van der Wal and H.J. Bork studentnumber: 839104017 and 838532340) email: petervanderwal2003@yahoo.com and hjbork@hotmail.com This paper describes the conceptual model and results of the 'management accountants survey 2013'. The survey is part of a longitudinal survey, earlier executed in 2004, 2007 and 2010 under responsibility of the 'Open Universiteit Nederland'. Secondly the dataset of this survey will be used by us to do our own analyses on the predicting value of the triggers 'personality factor: extraversion' and 'lever of control: interactive controls' on the management accounting role that comes close to a role defined as 'Business Partner'. Scientific research shows that there are different management accounting roles, and that these roles change and that preferences exist for certain roles (Verstegen B. , Loo, Mol, Slagter, & Geerkens, 2007). The main question that will be answered in this paper is which coherent combinations of activities are being executed by management accountants in 2013 in the Netherlands by master-graduates? And secondly which triggers of management accountants' activities predict to which cluster a management accountant belongs? The conceptual model of this research has been developed in 2004 (Verstegen B. , Loo, Mol, Slagter, & Geerkens, 2007). For this research the same 37 activities as in the former researches are included (appendix 1). In the trigger-set (appendix 1) some adaptations have been made for reasons of restricting the length of the survey and to pinpoint on particular research goals (e.g. personality and levers of control). The coherent combinations of activities were found by a factor-analysis and the groups of controllers by a cluster analysis. A regression analysis shows which trigger-items are most significant. The survey has been sent to 2.353 students that finished a controller-study on a Dutch University. There was a 9% (211) response with a completely filled survey. 137 of which indicated to work in a controller-function at the moment. These controllers have been included in the results. The factor-analysis results in six different coherent combinations of activities (factors). Shortly these factors are: advising top management on strategic level with result-effecting information (1), organizing internal reporting (2) organizing and representing the organization on external reporting (3), advising and managing changes by shortcomings in processes and control systems (4), maintaining and managing administrative organization- , information- and control systems (5) and organizing/executing risk management and internal audit (6). Factors 4, 5 and 6 are clustered in cluster TYPE I (125 controllers) and factors 1, 2 and 3 in cluster TYPE II (69 controllers). TYPE II can be associated with the management accountant role 'Business Partner', although the accountant keeps partly active in a scorekeeper role. The four most significant triggers for predicting being a TYPE II controller are 'Executing a risk-management task in order to meet compliance standards' (1), extraversion (2), company size in terms of fte (3) and gender (4).

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Clustering algorithms, pattern mining techniques and associated quality metrics emerged as reliable methods for modeling learners’ performance, comprehension and interaction in given educational scenarios. The specificity of available data such as missing values, extreme values or outliers, creates a challenge to extract significant user models from an educational perspective. In this paper we introduce a pattern detection mechanism with-in our data analytics tool based on k-means clustering and on SSE, silhouette, Dunn index and Xi-Beni index quality metrics. Experiments performed on a dataset obtained from our online e-learning platform show that the extracted interaction patterns were representative in classifying learners. Furthermore, the performed monitoring activities created a strong basis for generating automatic feedback to learners in terms of their course participation, while relying on their previous performance. In addition, our analysis introduces automatic triggers that highlight learners who will potentially fail the course, enabling tutors to take timely actions.

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A novel surrogate model is proposed in lieu of Computational Fluid Dynamics (CFD) solvers, for fast nonlinear aerodynamic and aeroelastic modeling. A nonlinear function is identified on selected interpolation points by
a discrete empirical interpolation method (DEIM). The flow field is then reconstructed using a least square approximation of the flow modes extracted
by proper orthogonal decomposition (POD). The aeroelastic reduce order
model (ROM) is completed by introducing a nonlinear mapping function
between displacements and the DEIM points. The proposed model is investigated to predict the aerodynamic forces due to forced motions using
a N ACA 0012 airfoil undergoing a prescribed pitching oscillation. To investigate aeroelastic problems at transonic conditions, a pitch/plunge airfoil
and a cropped delta wing aeroelastic models are built using linear structural models. The presence of shock-waves triggers the appearance of limit
cycle oscillations (LCO), which the model is able to predict. For all cases
tested, the new ROM shows the ability to replicate the nonlinear aerodynamic forces, structural displacements and reconstruct the complete flow
field with sufficient accuracy at a fraction of the cost of full order CFD
model.

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Attaching and effacing (A/E) lesions and actin polymerization, the hallmark of enteropathogenic Escherichia coli (EPEC), enterohemorrhagic E. coli (EHEC) and Citrobacter rodentium (CR) infections, are dependent on the effector Tir. Phosphorylation of Tir(EPEC/CR) Y474/1 leads to recruitment of Nck and neural Wiskott-Aldrich syndrome protein (N-WASP) and strong actin polymerization in cultured cells. Tir(EPEC/CR) also contains an Asn-Pro-Tyr (NPY(454/1)) motif, which triggers weak actin polymerization. In EHEC the NPY(458) actin polymerization pathway is amplified by TccP/EspF(U), which is recruited to Tir via IRSp53 and/or insulin receptor tyrosine kinase substrate (IRTKS). Here we used C. rodentium to investigate the different Tir signalling pathways in vivo. Following infection with wild-type C. rodentium IRTKS, but not IRSp53, was recruited to the bacterial attachment sites. Similar results were seen after infection of human ileal explants with EHEC. Mutating Y471 or Y451 in Tir(CR) abolished recruitment of Nck and IRTKS respectively, but did not affect recruitment of N-WASP or A/E lesion formation. This suggests that despite their crucial role in actin polymerization in cultured cells the Tir:Nck and Tir:IRTKS pathways are not essential for N-WASP recruitment or A/E lesion formation in vivo. Importantly, wild-type C. rodentium out-competed the tir tyrosine mutants during mixed infections. These results uncouple the Tir:Nck and Tir:IRTKS pathways from A/E lesion formation in vivo but assign them an important in vivo role.

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A literatura realça a importância do impacto do comportamento parental no desenvolvimento de ansiedade em crianças e adolescentes. Dado a pertinência do tema, o foco do presente estudo visa analisar o papel que a perceção dos adolescentes sobre os estilos educativos parentais tem sobre a manifestação de sintomatologia ansiosa. A amostra desta investigação envolveu 136 adolescentes do 3º ciclo do ensino básico, 48 rapazes e 88 raparigas com idades compreendidas entre os 12 e os 15 anos, com uma média de idades de 13,2 anos, recolhida no Colégio São Martinho em Coimbra. O protocolo de investigação incluiu os seguintes instrumentos de colheita de dados: Questionário Sociodemográfico, State-Trait Anxiety Inventory for Children (STAIC) e EMBU-A. Os resultados do estudo sugerem que os adolescentes mais velhos manifestam maior sintomatologia ansiosa, estatisticamente significativa ao nível da ansiedade-estado. No que respeita ao desempenho académico, são os adolescentes com elevado insucesso escolar que exteriorizam mais ansiedade-traço. Porém, não foram encontradas diferenças significativas na manifestação da ansiedade dos adolescentes em função das variáveis género, posição na fratria e habilitações literárias dos pais. Por seu lado, em relação aos estilos educativos parentais, os jovens que têm maior insucesso escolar percecionam níveis elevados de sobreproteção da mãe, e de rejeição do pai e da mãe. Os adolescentes que têm um pai com mais baixo nível de escolaridade percecionam maior rejeição materna, e são os filhos de mães com menos habilitações literárias que sentem maior sobreproteção da mãe e rejeição do pai. Verificou-se, em particular, uma associação significativa entre a rejeição paterna e níveis mais elevados de sintomatologia ansiosa. O modelo preditivo avançado no estudo confirma que a rejeição paterna, em conjunto com a idade do adolescente, são bons preditores da sintomatologia ansiosa. Especificamente, a rejeição paterna é evidenciada como o melhor preditor da sintomatologia ansiosa, sendo o principal responsável pela manifestação de ansiedade nos adolescentes. Os resultados sugerem que a rejeição do pai desencadeia níveis elevados de sintomatologia ansiosa. Assim, este estudo permite concluir que a rejeição paterna é o estilo educativo parental que exerce maior influência na manifestação de ansiedade nos adolescentes. / The literature highlights the importance of the impact of parental behavior on the development of anxiety in children and adolescents. Given the relevance of the topic, the focus of this study is to analyze the role that the adolescents’ perception about parental rearing styles have on the manifestation of anxiety symptoms. The sample of this research involved 136 adolescents from the 3rd cycle of basic education, 48 boys and 88 girls aged between 12 and 15 years, with a mean age of 13,2 years, gathered in Colégio São Martinho in Coimbra. The investigation protocol included the following data collection instruments: Sociodemographic Questionnaire, State-Trait Anxiety Inventory for Children (STAIC) and the EMBU-A. The results of the study suggest that older adolescents show greater anxiety symptoms, statistically significant at the level of state anxiety. With regard to academic performance, are adolescents with high failure rates that externalize more trait anxiety. However, there were significant differences in the manifestation of anxiety in adolescents function of the variables gender, sibling position and educational background of the parents. For its part, in relation to parental rearing styles, young people who have higher academic failure perceive high levels of overprotection of the mother, and rejection of father and mother. Adolescents who have a father with the lowest educational level perceive greater maternal rejection, and are the children of mothers with less qualification who feel greater overprotection of the mother and father's rejection. There was, in particular, a significant association between paternal rejection and higher levels of anxiety symptoms. The predictive model advanced in the study confirms that parental rejection, together with the adolescents’ age, are good predictors of anxiety symptoms. Specifically, parental rejection is evidenced as the best predictor of anxiety symptoms, being primarily responsible for the manifestation of anxiety in adolescents. The results suggest that the father rejection triggers high levels of anxiety symptoms. Thus, this study shows that rejection is the paternal parental rearing style that has more influence on the manifestation of anxiety in adolescents.

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Several lines of evidence converge to the idea that rapid eye movement sleep (REMS) is a good model to foster our understanding of psychosis. Both REMS and psychosis course with internally generated perceptions and lack of rational judgment, which is attributed to a hyperlimbic activity along with hypofrontality. Interestingly, some individuals can become aware of dreaming during REMS, a particular experience known as lucid dreaming (LD), whose neurobiological basis is still controversial. Since the frontal lobe plays a role in self-consciousness, working memory and attention, here we hypothesize that LD is associated with increased frontal activity during REMS. A possible way to test this hypothesis is to check whether transcranial magnetic or electric stimulation of the frontal region during REMS triggers LD. We further suggest that psychosis and LD are opposite phenomena: LD as a physiological awakening while dreaming due to frontal activity, and psychosis as a pathological intrusion of dream features during wake state due to hypofrontality. We further suggest that LD research may have three main clinical implications. First, LD could be important to the study of consciousness, including its pathologies and other altered states. Second, LD could be used as a therapy for recurrent nightmares, a common symptom of depression and post-traumatic stress disorder. Finally, LD may allow for motor imagery during dreaming with possible improvement of physical rehabilitation. In all, we believe that LD research may clarify multiple aspects of brain functioning in its physiological, altered and pathological states.

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Anaphylaxis is a serious, rare condition increasing in prevalence. This study explored the psychological experience of adult-onset anaphylaxis from patient, family and staff perspectives. Semi-structured interviews were conducted with twelve participants. Two global themes emerged from thematic analysis: ‘controllability’ (‘an unknown and distressing experience’, ‘the importance of control over triggers’ and ‘responsibility but no control: the impact on others’) and ‘conflict’ (‘rejecting illness identity’, ‘minimisation of risk’, ‘accessing specialist care: running in slow motion’ and ‘patient-centred versus service-centred care’). Findings highlight the importance of perceived control and emphasise the presence of conflict in the experience of this complex, episodic condition.

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Méthodologie:Cadre conceptuel: Principal-agent

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Background and Aims: Reproductive life events are potential triggers of mood episodes in women with bipolar disorder. We aimed to establish whether a history of premenstrual mood change and postpartum episodes are associated with perimenopausal episodes in women who have bipolar disorder. Methods: Participants were 339 post-menopausal women with DSM-IV bipolar disorder recruited into the Bipolar Disorder Research Network (www.bdrn.org). Women self-reported presence (N = 200) or absence (N = 139) of an illness episode during the perimenopausal period. History of premenstrual mood change was measured using the self-report Premenstrual Symptoms Screening Tool (PSST), and history of postpartum episodes was measured via semi-structured interview (Schedules for Clinical Assessment in Neuropsychiatry, SCAN) and inspection of case-notes. Results: History of a postpartum episode within 6 months of delivery (OR = 2.13, p = 0.03) and history of moderate/severe premenstrual syndrome (OR = 6.33, p < 0.001) were significant predictors of the presence of a perimenopausal episode, even after controlling for demographic factors. When we narrowed the definition of premenstrual mood change to premenstrual dysphoric disorder, it remained significant (OR = 2.68, p = 0.007). Conclusions: Some women who have bipolar disorder may be particularly sensitive to reproductive life events. Previous mood episodes in relation to the female reproductive lifecycle may help clinicians predict individual risk for women with bipolar disorder approaching the menopause. There is a need for prospective longitudinal studies of women with bipolar disorder providing frequent contemporaneous ratings of their mood to overcome the limitations of retrospective self-report data.