Occurrence Of Flashes Research Articles

Acupuncture for Hot Flashes in Postmenopausal Hemodialysis-Dependent Women: Two Case Reports

This study aimed to observe the effects of acupuncture for hot flashes in postmenopausal hemodialysis-dependent women. Two postmenopausal hemodialysis-dependent women were treated with individualized manual acupuncture for 1 and 3 months to reduce the occurrence of hot flashes and were observed through 7 and 11 months, respectively, from baseline. Hot flashes were significantly improved after acupuncture treatment in both of the patients, and the effects persisted through the final observation period (hot flash scores decreased from 57 to 33 and 22 at 1 and 11 months from baseline in patient 1, and from 14 to 6 and zero at 1 and 7 months from baseline in patient 2). The beneficial effects of acupuncture on quality of life were partially observed in these 2 patients. No acupuncture-related serious adverse events occurred during the study. Further controlled studies need to be conducted among larger samples to determine whether acupuncture is an effective and safe treatment for hot flashes in postmenopausal hemodialysis-dependent women.

Terrestrial gamma ray flashes correlated to storm phase and tropopause height

We compare the seasonal and geographical occurrence of terrestrial gamma ray flashes (TGFs) with global lightning maps and find that only part of the difference can be explained by differences in tropopause altitude. The altitude hypothesis suggests either that TGFs are produced only in conjunction with the highest lightning or that only the highest events are seen from space because of the easier escape of gamma rays from the atmosphere. We find that the differences in atmospheric transmission due to seasonal and geographical differences in tropopause height play a major but not dominant role in reconciling lightning and TGF maps and that other factors are needed to explain the remaining local differences. In a second analysis, we use radio atmospherics data from the World Wide Lightning Location Network to study at what time in the evolution of a storm TGFs tend to be seen. We find that, on average, TGFs lag the peak flash rate of the associated storm by 38 min, although the range of lags is extremely wide, including some cases where the TGF leads the peak flash rate.

Magneto-Ionic Process for Cloud Electrification

This paper presents a theory of cloud electrification by geomagnetic control. In the atmosphere, when ion-pairs produced by collision between cloud-particles are drifted in the W-E direction by the horizontal wind, the ions of opposite polarity get separated from each other under the influence of earth's magnetic field. Lorentz forces urge these ions to move in semi-circular trajectories at different altitudes, creating the positive bipolar charged structure of the thundercloud. The continuous charging process actuated by the magneto-ionic separation and the drift of the charged cloud-particles or snow crystals generate high electric fields in both vertical and horizontal planes within the cloud; as a result, Cloud-to-Ground (CG), Intra-Cloud (IC) both vertical and horizontal, and Cloud-to-Cloud (CC) discharges occur. The nature and frequency of these discharges are determined by the geomagnetic (CM) latitude of the place of observation. Maximum thunderstorm activity is expected to occur at intermediate CM latitude stations. During violent winter thunderstorms in the northern hemisphere, the direction of wind drift within the cloud becomes E-W; then a negative dipolar charge structure develops, with its N-region lying near the crest and the P-region near the bottom of the cloud. Leader strokes from such a negative dipolar cloud contribute positive charges to ground via CG discharges. This paper also includes explanations for the cause of occurrence of IC flashes at a level higher than the N-region in a positive dipolar cloud, and the role of the IC flash preceding the CG discharge, which neutralizes a part of the positive charge in the P-region. Consequently, an equal amount of negative charge becomes unbounded in the N-region, which actuates the CG leader stroke.

Abstract A1: Impact of CYP2D6∗10 and CYP3A5∗3 polymorphisms on the pharmacokinetics of tamoxifen in Asian breast cancer patients

Abstract Background: Tamoxifen (TAM) is a selective estrogen receptor modulator employed in the treatment of breast cancer. It is a prodrug with a complex metabolic pathway involving several phase I and II metabolic enzymes. TAM is metabolized by cytochrome P450 (CYP) enzymes to N-desmethyltamoxifen (NDM), 4-hydroxytamoxifen (4OHT) and endoxifen (END) with 4OHT and END being the active metabolites of TAM. CYP2D6 and CYP3A4/5 comprises the major CYP isoforms mediating the metabolism of TAM although other CYP isoforms also play a role. Polymorphisms present in genes encoding these CYP enzymes may influence the metabolism and pharmacokinetics of TAM and its metabolites. Methods: A total of 116 Asian breast cancer patients were genotyped for CYP3A5∗3 polymorphism while 104 of these patients were genotyped for CYP2D6. Plasma levels of TAM and its 3 metabolites were obtained at steady state. The occurrence of hot flashes were monitored. Results: The allelic frequencies of CYP2D6∗10 and CYP3A5∗3 in the breast cancer patients were 0.52 and 0.71, respectively. The plasma END level (median; range) of patients with CYP2D6∗10/∗10 (8.85; 6.27-34.68) was significantly lower compared to patients with CYP2D6∗1/∗1 (19.55; 4.18-42.56; pCYP2D6∗1/∗10 (16.18; 9.48-33.24; pCYP2D6∗10 was 359.02 ng/ml (124.7–590.65) and was significantly higher compared to patients with CYP2D6∗1/∗1 (239.27; 40.82-584.26; p=0.012). No associations were observed between the pharmacokinetics of TAM and CYP3A5∗3. Hot flashes, a common side-effect of TAM, occurred at an overall frequency of 0.208 in the patient population. Patients homozygous for the ∗10/∗10 genotype had the highest frequency of hot flashes compared to wild-type subjects (P>0.05). Conclusion: This exploratory study identified CYP2D6∗10 to be an important predictor of TAM pharmacokinetics in Asian breast cancer patients. Other polymorphisms present in CYP2D6 or genes encoding other enzymes involved in metabolism of TAM may be useful in explaining inter-individual variation in TAM pharmacokinetics. Citation Information: Clin Cancer Res 2010;16(7 Suppl):A1

Weight gain is associated with increased risk of hot flashes in breast cancer survivors on aromatase inhibitors.

Hot flashes in breast cancer survivors (BCS) receiving adjuvant aromatase inhibitor (AI) therapy are common, but risk factors for these symptoms are ill-defined. This study tested if body size is associated with hot flashes in BCS on AI therapy. A cross-sectional study of postmenopausal BCS receiving adjuvant AI therapy was performed. The primary outcome was occurrence of patient-reported hot flashes. The primary exposures of interest were current body size and weight change since breast cancer diagnosis. Three hundred participants were enrolled at a mean age of 61 years (range 33-86) after an average AI exposure of 23 months (range 1 month-9 years). Fifty-nine percent reported hot flashes, 32% reported moderate to severe hot flashes, and 25% reported significant worsening of hot flashes since starting AI therapy. Sixty-one percent experienced weight maintenance (±10 lb), while 27% had weight gain (gained 10 lb or more), and 11% had weight loss (lost 10 lb or more). In multivariable analysis, weight gain was independently associated with hot flash occurrence (OR 2.1, 95% CI 1.1-4.4) and hot flash severity (OR 2.6, 95% CI 1.3-5.0) after adjusting for confounding. Current body size was not associated with hot flash occurrence, severity or change with AI therapy. In an outpatient BCS population on AI therapy, weight gain is a risk factor for hot flash occurrence. Women who gained at least 10 lb since breast cancer diagnosis were two times more likely to have hot flashes than women who maintained or lost weight. These results support the thermoregulatory model of hot flashes and argue against a protective effect of body fat in this population.

Weight Gain Is Associated with Increased Risk of Hot Flashes in Breast Cancer Survivors on Aromatase Inhibitors.

Abstract Objective: Hot flashes in breast cancer survivors (BCS) receiving adjuvant aromatase inhibitor (AI) therapy are common, but risk factors for these symptoms are not well-defined. This study tested if body size is associated with hot flashes in BCS on AI therapy.Materials and methods: We performed a cross-sectional analysis of a cohort of postmenopausal women with Stages 0-III breast cancer receiving adjuvant AI therapy at a university hospital-based outpatient breast oncology clinic. Subjects provided patient-reported outcomes on hot flashes, current and pre-breast cancer weight and height, and additional demographic and treatment data.The primary outcome was occurrence of hot flashes. Secondary outcomes included hot flash severity and frequency. The exposures of interest were 1) current weight and 2) weight change since breast cancer diagnosis, categorized as weight loss (lost 10 pounds or more), maintenance (+/- 10 pounds), or gain (gained 10 pounds or more). Multivariable logistic regression models examined the independent association between hot flash outcomes and current weight or weight change while controlling for confounders.Results: 300 participants were enrolled at a mean age of 61 years (range 33-86) after mean duration of AI exposure of 23 months (range 1 month-9 years). 177 (59%) reported hot flashes overall, 96 (32%) reported moderate to very severe hot flashes, and 60 (20%) had at least 4 hot flashes daily. 182 (61%) experienced weight maintenance, while 81 (27%) had weight gain and 34 (11%) had weight loss. In a multivariable model, weight gain was independently associated with hot flash occurrence (OR 2.1, 95% CI 1.1-4.4) and hot flash severity (OR 2.4, 95% CI 1.4-4.9), but not hot flash frequency, after adjusting for current weight and height, age, smoking, race, prior chemotherapy and prior tamoxifen therapy. Hot flash occurrence was also significantly associated with current smoking (OR 5.1, 95% CI 1.1-24.0) and age (OR for each additional year of age 0.93, 95% CI 0.90-0.97). Current weight, alcohol use, AI type, and AI duration were not associated with any of the three outcomes.Conclusions: In an outpatient BCS population on AI therapy, weight gain is a risk factor for both hot flash occurrence and severity. Women who gained at least ten pounds since breast cancer diagnosis were two times more likely to have hot flashes than women who maintained or lost weight. These results support the thermoregulatory model of hot flashes and argue against a protective effect of body fat in this population.Support: ACS MRSG-08-110-01-CCE, ACS CCDA#-08-107-01, Pennsylvania Department of Aging Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1059.

Role of ethnicity in the expression of features of hot flashes

The overall goal of this study was to determine the role of ethnicity on features of hot flashes (HFs) in a population of menopausal women in North Central Texas. A total of 397 ethnically diverse menopausal women from North Central Texas were administered our Menopausal Vasomotor Symptoms (MVS) survey to ascertain accurate information about number, length, intensity and behaviorally disruptive effects of hot flash episodes for subsequent analysis for the role of ethnicity in the occurrence of hot flashes. The mean (SD) age for participants was 50.2 (5.3) years; 40% were Caucasian, 38% were African-American and 22% were Hispanic. To evaluate and identify potential associations of hot flash (HF) features, ethnicity, and other independent variables, ordinal/multinomial/binary logistic regression models were used to calculate crude and adjusted odds ratios (ORs) and 95% confidence intervals (CIs). The analysis demonstrates strong associations with ethnicity and the number of HF's/day, the length of each HF episode, the intensity of HFs, and the interruption of daily activities and sleep. Ethnicity was important in the crude and adjusted model describing the association between the number of HFs per day and ethnicity. African-American women were 2.22 (95% CI, 1.38–3.56) times and Hispanic women were 1.85 (95% CI, 1.08–3.18) times more likely to experience more frequent HFs per day than Caucasian women. In contrast, Hispanic women were less likely than Caucasian women to experience sweating and disruption of both daily activities and sleep. Collectively, our results show more frequent and more bothersome HFs in African-American women and more frequent, but less intense and bothersome HFs in Hispanic women in comparison to Caucasian women.

Serum leptin levels, hormone levels, and hot flashes in midlife women

To examine the associations between serum leptin levels, sex steroid hormone levels, and hot flashes in normal weight and obese midlife women. Cross-sectional study. University clinic. 201 Caucasian, nonsmoking women aged 45 to 54 years with a body mass index of <25 kg/m2 or >or=30 kg/m2. Questionnaire, fasting blood samples. Serum leptin and sex steroid hormone levels. Correlation and regression models were performed to examine associations between leptin levels, hormone levels, and hot flashes. Leptin levels were associated with BMI, with "ever experiencing hot flashes" (questionnaire), with hot flashes within the last 30 days, and with duration of hot flashes (>1 year, P=.03). Leptin was positively correlated with testosterone, free testosterone index, and free estrogen index and inversely associated with levels of sex hormone-binding globulin. In women with a body mass index>or=30 kg/m2, leptin levels no longer correlated with testosterone levels. Serum leptin levels are associated with the occurrence and duration of hot flashes in midlife women; however, no correlation was found between leptin and serum estradiol.

The Influence of Breast Cancer Treatment on the Occurrence of Hot Flashes

Approximately 65% of women report hot flashes (HFs) during or following breast cancer treatment. However, few studies have compared the occurrence of vasomotor symptoms according to the type of adjuvant treatment received, and little is known about other risk factors for HFs among this population. This longitudinal study aimed to: 1) compare the frequency and severity of HFs in breast cancer patients according to treatment regimen; 2) evaluate the potential contribution of hormone therapy on the frequency and severity of HFs; and 3) identify other potential risk factors for HFs in breast cancer patients. Forty-one women receiving radiation therapy and chemotherapy and 40 women receiving radiation therapy without chemotherapy completed a daily diary of HFs for seven days, and the vasomotor scale of the Menopause-Specific Quality of Life Questionnaire prior to and following each type of treatment, and at a three-month follow-up evaluation. Z-scores and percentiles computed from an age-matched control group ( n = 45) without a history of cancer revealed a higher frequency and severity of HFs among breast cancer patients compared with control participants. Chemotherapy and hormone therapy were both associated with increased HFs. Past use of hormone replacement therapy (HRT) and a lower body mass index (BMI) were significantly associated with more severe vasomotor symptoms. This study highlights the clinical significance of HFs among breast cancer patients, particularly in women receiving chemotherapy and hormone therapy, and the necessity to offer effective therapeutic strategies to relieve HFs in this population.

Filling-in visual motion with sounds

Information about the motion of objects can be extracted by multiple sensory modalities, and, as a consequence, object motion perception typically involves the integration of multi-sensory information. Often, in naturalistic settings, the flow of such information can be rather discontinuous (e.g. a cat racing through the furniture in a cluttered room is partly seen and partly heard). This study addressed audio-visual interactions in the perception of time-sampled object motion by measuring adaptation after-effects. We found significant auditory after-effects following adaptation to unisensory auditory and visual motion in depth, sampled at 12.5Hz. The visually induced (cross-modal) auditory motion after-effect was eliminated if visual adaptors flashed at half of the rate (6.25Hz). Remarkably, the addition of the high-rate acoustic flutter (12.5Hz) to this ineffective, sparsely time-sampled, visual adaptor restored the auditory after-effect to a level comparable to what was seen with high-rate bimodal adaptors (flashes and beeps). Our results suggest that this auditory-induced reinstatement of the motion after-effect from the poor visual signals resulted from the occurrence of sound-induced illusory flashes. This effect was found to be dependent both on the directional congruency between modalities and on the rate of auditory flutter. The auditory filling-in of time-sampled visual motion supports the feasibility of using reduced frame rate visual content in multisensory broadcasting and virtual reality applications.

The effect of CTP-347 on CYP2D6-mediated tamoxifen metabolism

11552 Background: The activity of tamoxifen is primarily mediated through its 4-hydroxy metabolites which are potent antagonists of the estrogen receptor in breast tissue. The 4-hydroxylation reaction is mediated through the cytochrome P450 isozyme CYP2D6. Unfortunately, high concentrations of endoxifen, the major 4-hydroxy metabolite, have also been implicated in the occurrence of hot flashes. Although paroxetine has been demonstrated to reduce the frequency of hot flashes in investigator trials of patients with breast cancer, co- administration would reduce the effectiveness of tamoxifen since paroxetine has been shown to be a mechanism-based inactivator of CYP2D6. CTP-347 is a new chemical entity in which key hydrogen atoms of paroxetine are replaced with deuterium atoms. CTP-347 is being developed for the treatment of post-menopausal and tamoxifen-induced hot flashes and will enter clinical trials in mid-2008. Methods: Serotonin and norepinephrine reuptake inhibition was measured in rat synaptosomes u...

In vivo vasodilating mechanisms: who's NOS involved?

appreciate the importance and difficulty of identifying cellular mechanisms in physiological conditions. Indeed, 7-NI was administrated by intradermal microdialysis (2 mm) allowing large local drug concentration with local effects at the site of administration and thus avoiding systemic effects. Data were normalized to the SNP-induced maximal vasodilatation performed at the end of each protocol. Changes in skin blood flow were monitored by laser‐Doppler flowmetry (LDF) that gives continuous beat-to-beat information specific to cutaneous microvascular perfusion in a non-invasive manner. LDF measurements provide a robust approach to evaluate mechanisms of microvascular dilatation and their modification by physiological perturbations. The study reported that during nNOS inhibition, the skin vasodilatation due to whole-body heating was attenuated (∼30%) in contrast to local skin heating. The authors demonstrated that, in vivo, the nNOS isoform is responsible for NO generation during centrally mediated, reflex cutaneous active vasodilatation in whole-body heating, but is not involved in increasing skin blood flow in response to axon reflex-mediated, local skin heating. This study also showed that the nNOS isoform generates NO from the very initial phase of cutaneous active vasodilatation and continues during prolonged whole-body heat stress. However, Kellogg et al. (2008) strongly suggest that NO acts to increase synergistically the vasodilating effects of other neurotransmitters rather than acting as a direct mediator of vasodilatation. Interestingly, they excluded any participation of eNOS in centrally mediated reflex cutaneous active vasodilatation since studies using l-NAME, a non-selective isoform NOS antagonist, reported approximately an identical attenuation of 30% of skin blood flow increases to that of 7-NI, a selective nNOS antagonist, highlighting the possibility that nNOS is the sole NOS

Mental Workload under Time Pressure can Trigger Frequent Hot Flashes in Menopausal Women

The aim of this study is to examine the relationship between mental workload and occurrence of hot flashes. Twelve women with moderate to severe menopausal hot flashes participated in the study. Subjects participated in both a mental arithmetic task (Task) and control (Non-task) experiments. We measured heart rate, heart rate variability, blood pressure, near infrared spectroscopy, skin temperature, and skin potential level. The incidence of hot flashes was greater in Task than in Non-task. No significant differences between before, during and after hot flashes emerged for the percentage of correct responses and reaction time. However, the percentage of correct responses for two subjects among the ten who experienced hot flashes in Task substantially declined during hot flashes. Chest skin temperatures increased in both Task and Non-task during hot flashes, and regional oxygen saturation was significantly higher in Non-task than in Task. The present study suggested that mental workload under time pressure might be a risk factor for menopausal hot flashes, and the performance of most people who experienced hot flashes was not affected by hot flashes, however, work-related difficulties due to cognitive disturbance during hot flashes might arise in some people.

Observation of Current and Leader Development Characteristics of Winter Lightning

Current and leader development characteristics of winter lightning occurring in the coastal area of the Sea of Japan are reviewed. The characteristics of winter lightning are different from those of usual lightning that occurs mainly in summer. The occurrence of upward flashes, the percentage of current polarities, and the median values of current peaks in winter lightning are summarized. Typical current waveforms and the corresponding leader developments of winter lightning observed at the chimney of the Fukui thermal plant are shown. We examined the parameters (peak, duration, charge transfer, action integral) of the current waveforms of winter lightning.

Is It Hot in Here, or Is This Insomnia?

Several studies have found that being female is a risk factor for insomnia, possibly because women are more likely to develop depression and anxiety disorders (both commonly associated with sleep disturbances) and because sleep problems might emerge secondary to reproductive cycle–related changes. Among other factors, the association between menopause and insomnia has been attributed to the occurrence and severity of nocturnal hot flashes because they may interrupt sleep. However, …

The formation of helium white dwarfs in close binary systems -- II

We present a set of calculations of the evolution of low-mass, solar composition stars in close binary systems together with a canonical 1.4-M⊙, neutron star (NS). We restrict the initial mass and period values to those that give rise to the formation of ultracompact systems or low-mass helium white dwarf (He WD) stars. Specifically, we computed the evolution of 40 systems for which the initial masses of the normal (donor) stars were of 1.00, 1.25, 1.50, 1.75, 2.00, 2.50, 3.00 and 3.50 M⊙, while the range of initial periods covered in this work was from 0.5 to 12 d. Calculations were performed employing the binary hydro code developed by the present authors, which handles the mass transfer rate in a fully implicit way together with state-of-the-art physical ingredients and diffusion processes. In this work we have assumed the standard scheme for the orbital evolution of the binary, considering the usual processes that produce angular momentum losses: mass loss from the system, magnetic braking and gravitational radiation. In the main part of this work we assume that the NS is able to retain only half of the matter coming from the donor star. The range of final masses has been from 0.01961 to 0.34351 M⊙ and periods from 39 min to 187 d. 26 out of the 40 considered systems give rise to the formation of a He WD as a compact remnant. In performing a comparison of our results with observations, we have employed three WD-NS systems, which are among the best known ones. These are PSR J0437−4715, PSR J1012+5307 and PSR B1855+09. In order to obtain good agreement between models and observations we have had to assume that the NS is able to retain only ≈10 per cent of the material released by the donor star. Otherwise, for the cases of PSR J0437−4715 and PSR B1855+09 we would be in conflict with the observed NS masses. For these two objects we have been able to fit WD and NS masses, the orbital period and also the time-scale for cooling of the WD with the evolution of one binary system. For the case of PSR J1012+5307, the problem is more delicate because the object has a mass near the threshold for the occurrence of thermonuclear flashes and the initial period is close to bifurcation point.

Assessment of hot flashes and clinical correlates in breast cancer patients receiving tamoxifen or third-generation aromatase inhibitors

8015 Background: The aim of this study was to assess prevalence and severity of hot flashes in breast cancer patients with or without endocrine treatment and to identify patients at risk in whom interventions may be necessary. Methods: 233 postmenopausal breast cancer patients belonging to various stages were included in this cross-sectional study. They completed local treatments and chemotherapy for at least 3 months and were without evidence of disease progression on inclusion. Current hormonal treatments were: None, 58 pts; tamoxifen, 79 pts; FEMTA trial (double blind adjuvant tamoxifen vs letrozole) 49 pts; letrozole, 26 pts; exemestane, 21 pts. Frequency and severity of hot flashes and other menopausal symptoms were recorded in a 14-day diary. Statistical analysis was done with non-parametric test Mann-Whitney U test and Pearson’s correlation test. Results: Prevalence of hot flashes was highest under tamoxifen (70%) and in the FEMTA trial (69%). Hot flashes were less frequent in patients without hormonal therapy (52%) and in patients under aromatase inhibitors (49%), both groups being significantly different than patients receiving tamoxifen (p=0.054 and p= 0.013, respectively). No significant difference in hot flashes was seen when comparing aromatase inhibitors vs no hormonal therapy, or tamoxifen vs FEMTA. Age was inversely correlated with occurrence of hot flashes (p< 0.0001). Patients with lower educational level and those in partnered relationships reported more hot flashes (all p≤ 0.046). Moreover, the occurrence of hot flashes was significantly correlated to the presence of nervousness and depressive mood (p=0.02) and was associated with other menopausal symptoms such as vaginal dryness (p=0.073) and memory problems (p=0.072). Conclusions: Although hot flashes are most severe under tamoxifen, a significant proportion of patients receiving third generation aromatase inhibitors and even untreated patients experience this symptom. This underscores the need for finding effective and safe non-hormonal interventions. No significant financial relationships to disclose.

The role of anxiety and hormonal changes in menopausal hot flashes.

To estimate the association of anxiety with menopausal hot flashes in the early transition to menopause. A randomly identified, population-based cohort of midlife women followed up for 6 years to assess reproductive hormones and other physical, emotional, and behavioral factors. At enrollment, the women were premenopausal, aged 35 to 47 years, and had regular menstrual cycles in the normal range. Enrollment was stratified to obtain equal numbers of African American (n = 219) and white (n = 217) women. At the 6-year endpoint, 32% of the women were in the early transition stage and 20% reached the late menopausal transition or were postmenopausal. Reports of hot flashes increased with the transition stages, which were determined by bleeding patterns. At endpoint, hot flashes were reported by 37% of the premenopausal women, 48% of those in the early transition, 63% of women in the late transition, and 79% of the postmenopausal women. Anxiety scores were significantly associated with the occurrence of hot flashes and were also significantly associated with the severity and frequency of hot flashes (each outcome at P < 0.001). Compared with women in the normal anxiety range, women with moderate anxiety were nearly three times more likely to report hot flashes and women with high anxiety were nearly five times more likely to report hot flashes. Anxiety remained strongly associated with hot flashes after adjusting for menopause stage, depressive symptoms, smoking, body mass index, estradiol, race, age, and time. In a predictive model, anxiety levels at the previous assessment period and the change in anxiety from the previous assessment period significantly predicted hot flashes (P < 0.001). Anxiety is strongly associated with menopausal hot flashes after adjusting for other variables including menopause stage, smoking, and estradiol levels. Anxiety preceded hot flashes in this cohort. Additional studies are needed to examine the duration of menopausal hot flashes and to determine whether treatments that target anxiety effectively reduce menopausal hot flashes.

Cigarette smoking, estrogen levels, and hot flashes in midlife women

Objective The aims of this study were to examine the association of smoking with the occurrence, frequency, and severity of hot flashes and to determine whether the mechanism by which active cigarette smoking increases the risk of hot flashes is by lowering estradiol and estrone levels. Methods A case–control study was conducted among women aged 45–54 years to examine risk factors for hot flashes. Cases were women who reported ever experiencing hot flashes ( n = 353). Controls were women who reported never experiencing hot flashes ( n = 258). Each participant completed a questionnaire and provided a blood sample that was used to measure estradiol and estrone levels. Results The results showed that both current and ever smokers had higher odds than never smokers of experiencing any and more severe hot flashes. Further, significant positive associations were observed between frequency and duration of smoking and the experiencing of any and more severe hot flashes. Smoking was not associated with estradiol or estrone levels in univariate analyses. In addition, the odds ratios for the associations between the cigarette smoking variables and hot flashes did not change when the hormone variables were added to the model. Conclusions These findings indicate that smoking is associated with the occurrence of any and more severe hot flashes, independent of estrogen levels.

Identification and analysis of flash cells in thunderstorms

The convection-cell structure of a thunderstorm, often visible in the precipitation pattern of weather radar images, can also be identified in the clustering of ground flashes when their rate is high enough. The flashes can be grouped into cells with a set of rules applied to the time-ordered sequence of flash locations. A flash is associated with a group (cell) of older flashes if its distance and time lag are short enough, and some auxiliary conditions are fulfilled. With a careful choice of parameters the grouping algorithm, called Cellsearch, is able to resolve the flashes of a thunderstorm into a reasonable collection of ‘flash cells’ showing appropriate sizes, lifetimes and movements. The unavoidable occurrence of stray flashes, either true or caused by inaccurate locations, makes it necessary to reject some flashes from the cells and emphasize those in the cell core. All moderate-and high-activity thunderstorms in Finland during 1998–2002 are analysed for their flash-cell properties, and some representative cases are studied more closely. Copyright © 2005 Royal Meteorological Society