Basal Temperature Research Articles

Fine‐Scale Geothermal Heat Flow in Antarctica Can Increase Simulated Subglacial Melt Estimates

AbstractAntarctic geothermal heat flow (GHF) affects the thermal regime of ice sheets and simulations of ice and subglacial meltwater discharge to the ocean, but remains poorly constrained. We use an ice sheet model to investigate the impact of GHF anomalies on subglacial meltwater production in the Aurora Subglacial Basin, East Antarctica. We find that spatially‐variable GHF fields produce more meltwater than a constant GHF with the same background mean, and meltwater production increases as the resolution of GHF anomalies increases. Our results suggest that model simulations of this region systematically underestimate meltwater production using current GHF models. We determine the minimum basal heating required to bring the basal ice temperature to the pressure melting point, which should be taken together with the scale‐length of likely local variability in targeting in‐situ GHF field campaigns.

Tracking of menstrual cycles and prediction of the fertile window via measurements of basal body temperature and heart rate as well as machine-learning algorithms

BackgroundFertility awareness and menses prediction are important for improving fecundability and health management. Previous studies have used physiological parameters, such as basal body temperature (BBT) and heart rate (HR), to predict the fertile window and menses. However, their accuracy is far from satisfactory. Additionally, few researchers have examined irregular menstruators. Thus, we aimed to develop fertile window and menstruation prediction algorithms for both regular and irregular menstruators.MethodsThis was a prospective observational cohort study conducted at the International Peace Maternity and Child Health Hospital in Shanghai, China. Participants were recruited from August 2020 to November 2020 and followed up for at least four menstrual cycles. Participants used an ear thermometer to assess BBT and wore the Huawei Band 5 to record HR. Ovarian ultrasound and serum hormone levels were used to determine the ovulation day. Menstruation was self-reported by women. We used linear mixed models to assess changes in physiological parameters and developed probability function estimation models to predict the fertile window and menses with machine learning.ResultsWe included data from 305 and 77 qualified cycles with confirmed ovulations from 89 regular menstruators and 25 irregular menstruators, respectively. For regular menstruators, BBT and HR were significantly higher during fertile phase than follicular phase and peaked in the luteal phase (all P < 0.001). The physiological parameters of irregular menstruators followed a similar trend. Based on BBT and HR, we developed algorithms that predicted the fertile window with an accuracy of 87.46%, sensitivity of 69.30%, specificity of 92.00%, and AUC of 0.8993 and menses with an accuracy of 89.60%, sensitivity of 70.70%, and specificity of 94.30%, and AUC of 0.7849 among regular menstruators. For irregular menstruators, the accuracy, sensitivity, specificity and AUC were 72.51%, 21.00%, 82.90%, and 0.5808 respectively, for fertile window prediction and 75.90%, 36.30%, 84.40%, and 0.6759 for menses prediction.ConclusionsBy combining BBT and HR recorded by the Huawei Band 5, our algorithms achieved relatively ideal performance for predicting the fertile window and menses among regular menstruators. For irregular menstruators, the algorithms showed potential feasibility but still need further investigation.Trial registrationChiCTR2000036556. Registered 24 August 2020.

Novel Method to Assess Endothelial Function via Monitoring of Perfusion Response to Local Heating by Imaging Photoplethysmography.

Endothelial dysfunction is one of the most important markers of the risk of cardiovascular complications. This study is aimed to demonstrate the feasibility of imaging photoplethysmography to assess microcirculation response to local heating in order to develop a novel technology for assessing endothelial function. As a measure of vasodilation, we used the relative dynamics of the pulsatile component of the photoplethysmographic waveform, which was assessed in a large area of the outer surface of the middle third of the subject’s forearm. The perfusion response was evaluated in six healthy volunteers during a test with local skin heating up to 40–42 °C and subsequent relaxation. The proposed method is featured by accurate control of the parameters affecting the microcirculation during the prolonged study. It was found that in response to local hyperthermia, a multiple increase in the pulsation component, which has a biphasic character, was observed. The amplitude of the first phase of the perfusion reaction depends on both the initial skin temperature and the difference between the basal and heating temperatures. The proposed method allows the assessment of a reproducible perfusion increase in response to hyperthermia developed due to humoral factors associated with the endothelium, thus allowing detection of its dysfunction.

Effects of moderate-continuous and high-intensity interval aerobic training on cardiac function of spontaneously hypertensive rats.

The aim of this study was to verify the effects of moderate-intensity continuous (MICT) and high-intensity interval (HIIT) aerobic training on cardiac morphology and function and the mechanical properties of single cardiomyocytes in spontaneously hypertensive rats (SHR) in the compensated phase of hypertension. Sixteen-week-old male SHR and normotensive Wistar (WIS) rats were allocated to six groups of six animals each: SHR CONT or WIS CONT (control); SHR MICT or WIS MICT (underwent MICT, 30 min/day, five days per week for eight weeks); and SHR HIIT or WIS HIIT (underwent HIIT, 30 min/day, five days per week for eight weeks). Total exercise time until fatigue and maximum running speed were determined using a maximal running test before and after the experimental period. Systolic (SAP), diastolic (DAP), and mean (MAP) blood pressures were measured using tail plethysmography before and after the experimental period. Echocardiographic evaluations were performed at the end of the experimental period. The rats were euthanized after in vivo assessments, and left ventricular myocytes were isolated to evaluate global intracellular Ca2+ transient ([Ca2+]i) and contractile function. Cellular measurements were performed at basal temperature (~37°C) at 3, 5, and 7 Hz. The results showed that both training programs increased total exercise time until fatigue and, consequently, maximum running speed. In hypertensive rats, MICT decreased SAP, DAP, MAP, interventricular septal thickness during systole and diastole, and the contraction amplitude at 5 Hz. HIIT increased heart weight and left ventricular wall thickness during systole and diastole and reduced SAP, MAP, and the time to peak [Ca2+]i at all pacing frequencies. In conclusion, both aerobic training protocols promoted beneficial adaptations to cardiac morphology, function, and mechanical properties of single cardiomyocytes in SHR.

A comparison of app-defined fertile days from two fertility tracking apps using identical cycle data

ObjectiveThe Natural Cycles app employs daily basal body temperature to define the fertile window via a proprietary algorithm and is clinically established effective in preventing pregnancy. We sought to (1) compare the app-defined fertile window of Natural Cycles to that of CycleProGo, an app that uses BBT and cervical mucus to define the fertile window and (2) compare the app-defined fertile windows to the estimated physiologic fertile window. Study DesignDaily BBT were entered into Natural Cycles from 20 randomly selected regularly cycling women with at least 12 complete cycles from the CycleProGo database. The proportion of cycles with equivalent (±1 cycle day) fertile-window starts and fertile-window ends was determined. The app-defined fertile windows were then compared to the estimated physiologic fertile window using Peak mucus to estimate ovulation. ResultsFifty seven percent of cycles (136/238) had equivalent fertile-window starts and 36% (72/181) had equivalent fertile-window end days. The mean overall fertile-window length from Natural Cycles was 12.8 days compared to 15.1 days for CycleProGo (p < 0.001). The Natural Cycles algorithm declared 12% to 30% of cycles with a fertile-window start and 13% to 38% of cycles with a fertile-window end within the estimated physiologic fertile window. The CycleProGo algorithm declared 4% to 14% of cycles with a fertile-window start and no cycles with a fertile-window end within the estimated physiologic fertile window. ConclusionsNatural Cycles designated a higher proportion of cycles days as infertile within the estimated physiologic fertile window than CycleProGo. ImplicationsUse of cervical mucus in addition to BBT may improve the accuracy of identifying the fertile window. Additional studies with other markers of ovulation and the fertile window would give additional insight into the clinical implications of app-defined fertile window differences.

The reproductive endocrine feature and conception outcome of women with unknown etiological menstrual cycle (36–45 days) with long follicular phase

Objective To explore the reproductive endocrine feature and conception outcome of women with unknown etiological long menstrual cycle (LMC) (36–45 days) with long follicular phase. Methods In the cohort study, we included 80 women with unknown etiological long menstrual cycle of biphasic basal body temperature (BBT) lasting for 36–45 days and 87 controls with normal cycle of biphasic BBT into LMC group and NMC group, respectively. Serum hormone levels, fasting glucose, and insulin of participants were tested, and ovulation was observed by ultrasound. The conception outcome was followed up within 12 menstrual cycles. Results In the LMC group, the rate of abnormality of HOMA-insulin resistance index (40.0% vs. 20.7%, p < .01), luteal phase defect (30.9% vs. 13.8%, p < .05) and abnormality of FSH/LH ratio (15.6% vs. 5.7%, p < .05) were all significantly higher, but the serum estradiol level on the day before ovulation (261.10 pg/mL vs. 320.26 pg/mL, p < .01) was lower. The rate of poor ovulation quality (31.3% vs.15.4%, p < .05) in the LMC group was significantly higher than the NMC group. In the LMC group, the natural conception rate within 12 menstrual cycles was lower (41.9% vs. 66.2%, p < .01), whereas the spontaneous abortion rate in early pregnancy (29.0% vs. 9.8%, p < .05) and the conversion rate (21.6% vs. 5.2%, p < .01) to anovulation within 12 cycles were significantly higher. Conclusions Women with unknown etiological menstrual cycle (36–45 days) with long follicular phase have greater endocrine abnormality and higher risk of spontaneous abortion, infertility, and conversion to anovulation. Moderate early intervention may be advisable for these women, especially those who wish to get pregnant.

A Method of Microwave Radiothermometry in Studies of Circadian Rhythms of Brain Temperature

We studied the possibility of using microwave radiothermometry of the brain in biorhythmology. It was found that the temperature variability of the frontal lobes of the right and left hemispheres strictly corresponded to the 24-h cycle was characterized by the oscillation amplitude of 1.2-1.4°C, which significantly exceeded the amplitude of the basal temperature. A conclusion was made about the informative value of the method of noninvasive registration of the 24-h dynamics of the brain temperature.

P-631 Day Length Predicts Ovulatory Shifts in Women’s Reproductive Function

Abstract Study question Is there a relationship between day length and ovulation rate in women of reproductive age? Summary answer Analysis showed that increasing day length is associated with higher ovulation rate in women of reproductive age in both Sweden and the United States (US). What is known already Historically, winter months have been characterised by threatening survival conditions, such as reduced food availability and lower temperatures. Day length, or photoperiod, provides a reliable indication of upcoming seasonal changes, which promotes season-specific adaptations to behaviours and reproductive systems in mammals. To avoid the survival threats the winter months present, mammals with long gestation periods typically exhibit increased breeding as photoperiods increase. As humans also possess long gestation periods, it may be that humans similarly adapt to increasing photoperiods by exhibiting seasonal shifts in reproductive functioning. Study design, size, duration This retrospective analysis of basal body temperature (BBT) data from the Natural Cycles contraceptive app included approximately 115,000 Natural Cycles users’ data, amounting to approximately 1.3 million cycles from May 2014 - January 2021. BBT was used to confirm ovulation, the rate of which was calculated and compared to the number of hours daylight users experienced based on the geographical location in which they had registered for the app. Participants/materials, setting, methods We exclude cycles with missing data for any of the studied variables leaving ∼180k Swedish and ∼150K US cycles. The Meteostat library supplied the temperature on the start date of each user cycle. The Suntime library was used to determine the number of hours of daylight users were exposed to on the start date of each cycle, which used the geographic coordinates of the users’ reported country of residence. Main results and the role of chance Menstrual Cycle data from approximately 115 thousand Natural Cycles app users aged between 18-62 from two geographic groups, Sweden and the US. Data from cycles during and immediately following the event of a miscarriage, pregnancy, or instance of taking an emergency contraceptive, as well as the two cycles immediately following a completed pregnancy. Using a generalised logistic mixed-effects model, implementation via GPBoost, user-specific variation in ovulation rate as a function of location-specific day length was assessed while controlling for age, cycle length, body mass index (BMI), daily temperature, and education level. We find that day length is significantly correlated with higher ovulation (p &amp;lt; 0.01) in both the US and Swedish cohort. Limitations, reasons for caution Ovulation rate and day length may have emerged as a function a several underlying mechanisms, including the optimisation of conditions for childbirth, the optimisation of conditions for conception and early embryonic development, or a decrease in ovulation during the darker, winter months as a result of investment in immune function. Wider implications of the findings Photoperiod may be an important regulator of human reproductive activity, providing some preliminary evidence of seasonal changes to women’s ovulatory functioning. Furthermore, birth rate as a measurement of seasonal reproductive patterns in humans may not be as stable or accurate a measure for contemporary analyses of women’s reproductive functioning. Trial registration number 000000

P-732 Definitions and diagnostic criteria for unexplained infertility (UI) – a systematic review

Abstract Study question What are the various inclusion criteria for the definition of unexplained infertility used for recruitment to clinical trials, and is there homogeneity of these definitions? Summary answer There is a need to standardise the definition of unexplained infertility when recruiting for clinical trials to optimise interpretation of results and allow appropriate meta-analysis. What is known already Unexplained infertility (UI) is a diagnosis of exclusion. The pathology underlying this diagnosis is likely to include different subtle contributing factors. Unfortunately there is no universally accepted definition of unexplained infertility. NICE in the UK, and ACOG/ASRM both have lists of recommended investigations but no specific minimum standards to define UI. Even the ICMART definition is ambiguous, describing ‘apparently normal’ ovarian function and ejaculate. This may lead to heterogeneity between inclusion criteria in relevant research studies. This introduces selection bias and renders meta-analysis of trial results less meaningful. A single definition would improve the quality of research for this important diagnosis. Study design, size, duration A systematic review of primary research investigating definitions of unexplained infertility in humans. A thorough search of online databases Medline and Embase was performed from inception to November 2021. A bespoke Excel spreadsheet was used to collect data for baseline study characteristics and outcome data. Results are reported as percentages. Participants/materials, setting, methods The search strategy included all primary research on heterosexual couple unexplained infertility in human participants. Papers with specified inclusion criteria were included and no date or language restrictions were applied. From 663 results, title and abstract screening identified 83 duplicates and 6 studies unsuitable for the review. A further 275 papers were excluded after full-text screening. 241 papers remained and their inclusion criteria recorded and analysed. Main results and the role of chance Only 35.7% of papers specified duration of infertility. Timescales varied from 1 year (46.5%), 2 years (39.5%) or 3 years (14%). 85% papers specified that semen analysis should be ‘normal’. Of these, 40% used the most recent WHO criteria. No other national or international criteria for grading semen analysis was identified. 90% studies required fallopian tube patency as an inclusion criteria. Of these, 65.4% specified bilateral patency. Methods for demonstrating patency included hysterosalpingogram (HSG) (15.7%), laparoscopy (18.4%), a combination of either (29.5%) or both (24.4%) of these or hystero-contrast-salpingography (0.9%). 11.5% papers did not specify an imaging modality. 48.5% included studies mentioned uterine cavity assessment, 65% of these using HSG to assess the cavity, other methods mentioned include ultrasound (26.5%) or hysteroscopy (15.4%). Only 5.4% papers required either exclusion of or evidence of only minimal endometriosis 80.5% of included papers required evidence of regular ovulation. 58.7% used luteal serum progesterone levels, 41.2% required regular cycles (patient-reported) and 17.5% used basal body temperature pattern assessment. Other methods mentioned by a minority of papers include endometrial biopsy, ultrasound follicular tracking, serum and urinary luteinising hormone levels. 44% studies required normal endocrine profiles of which 66% measured prolactin and FSH and 50% measured thyroid function. Limitations, reasons for caution The strength of this study is that we included all primary research papers studying unexplained infertility with no time limitations. Included studies originated from across the world. This is a thorough representation of criteria used across all clinical trials for unexplained infertility. Wider implications of the findings Only 63/241 (26%) studies included duration of infertility, tubal patency, proof of ovulation and semen analysis in their inclusion criteria. This demonstrates the need for standardisation of the definition of unexplained infertility. If future research can apply the same inclusion criteria this will reduce selection bias and allow appropriate meta-analysis. Trial registration number NA

Tree growth is connected with distribution and warming-induced degradation of permafrost in southern Siberia.

Hemiboreal and boreal forests growing at the southern margin of the permafrost distribution are vulnerable to climate warming. However, how climate warming threatens the growth of dominant tree species that are distributed on permafrost remains to be determined, particularly in synchrony with warming-induced permafrost degradation. Tree growth in the permafrost region of southern Siberia was hypothesized to be highly sensitive to temperature increasing and warming-induced permafrost degradation. To test this hypothesis, we sampled the tree ring width of 535 trees of dominant species, larch (including Larix gmelinii and L. sibirica) and white birch (Betula platyphylla), in ten hemiboreal to boreal forest plots within different permafrost zones. The relationships between the tree ring basal area index (BAI) and temperature, precipitation, and the Palmer drought severity index (PDSI) were compared among plots located in two permafrost zones. In the isolated permafrost zone, white birch grows better than larch and is not drought-stressed (p < .05). We suggest that the deep-rooted white birch benefits from the water from thawing permafrost, while the growth of the shallow-rooted larch is stressed by drought. In the sporadic discontinuous permafrost zone, both white birch and larch benefited from permafrost melting, but the sensitivity of larch growth to PDSI is still significant (p < .05), indicating drought is still an important climatic factor limiting the growth of larch. Our results imply that the permafrost degradation caused by climate warming affects tree growth by creating the root layer additional water source. In the future, it is necessary to focus on monitoring permafrost degradation to better predict forest dynamics at the southern margin of the permafrost distribution.

An increase in skin blood flow induced by fluid challenge is associated with an increase in oxygen consumption in patients with circulatory shock.

To investigate whether an increase in skin blood flow (SBF) after fluid challenge was associated with an increase in oxygen consumption (VO2) in patients with circulatory shock. We studied 62 patients with shock who required fluid challenge. Using laser Doppler, we measured finger SBF at basal temperature (SBFBT) and after a thermal challenge test (SBFTCT), before and after a fluid challenge (500 ml of Plasmalyte®). In fluid responders (i.e., increase in cardiac index ≥15%), VO2 responders (VO2R) were those with a ≥15% increase in VO2. Of the 62 patients, 33 were fluid responders and 16 of these were VO2R. At baseline, VO2R had lower SBFBT (21[14-52] vs 83[24-116] PU, p = 0.03) and SBFTCT (2.1[1.2-3.3] vs 4.4[2.2-5.6] PU/°C, p = 0.02) than VO2 non-responders (VO2NR); hemodynamic variables were not significantly different. The increase in SBFBT (∆SBFBT) after fluid challenge was greater in VO2R than in VO2NR (141[83-174] vs 57[17-150]%, p = 0.03). Areas under the curves for baseline SBFTCT (0.83 ± 0.07 [0.68-0.98]) and ∆SBFBT (0.90 ± 0.05 [0.75-1.0]) to predict ∆VO2 ≥ 15% were higher than for other variables. A lower baseline SBFTCT and a greater ∆SBFBT can identify patients in whom VO2 will increase after fluid challenge, suggesting an improvement in cellular metabolism.

Fertility Awareness-Based Methods for Women's Health and Family Planning.

BackgroundFertility awareness-based methods (FABMs) educate about reproductive health and enable tracking and interpretation of physical signs, such as cervical fluid secretions and basal body temperature, which reflect the hormonal changes women experience on a cyclical basis during the years of ovarian activity. Some methods measure relevant hormone levels directly. Most FABMs allow women to identify ovulation and track this “vital sign” of the menstrual or female reproductive cycle, through daily observations recorded on cycle charts (paper or electronic).ApplicationsPhysicians can use the information from FABM charts to guide the diagnosis and management of medical conditions and to support or restore healthy function of the reproductive and endocrine systems, using a restorative reproductive medical (RRM) approach. FABMs can also be used by couples to achieve or avoid pregnancy and may be most effective when taught by a trained instructor.ChallengesInformation about individual FABMs is rarely provided in medical education. Outdated information is widespread both in training programs and in the public sphere. Obtaining accurate information about FABMs is further complicated by the numerous period tracking or fertility apps available, because very few of these apps have evidence to support their effectiveness for identifying the fertile window, for achieving or preventing pregnancy.ConclusionsThis article provides an overview of different types of FABMs with a published evidence base, apps and resources for learning and using FABMs, the role FABMs can play in medical evaluation and management, and the effectiveness of FABMs for family planning, both to achieve or to avoid pregnancy.

Menstrual Cycle Modulates the Contribution of Dry Heat Loss to Total Heat Loss During Exercise in Warm‐Dry Conditions in Young, Recreationally Active Females: Preliminary Findings

The mid‐luteal phase of the menstrual cycle is characterized by an upward shift in basal body core temperature secondary to elevated circulating estradiol and progesterone levels as compared to the early‐follicular phase. This elevation in body core temperature, perhaps together with increased estradiol‐mediated cutaneous vasodilation, may increase convective and radiative (dry) heat loss by improving core‐to‐skin heat transfer. This increase in dry heat loss may, in turn, reduce the need for sweat secretion (evaporative heat loss) without necessarily altering the relative contribution of these avenues to total heat exchange. Thus, the purpose of this study was to evaluate the hypothesis that females in the mid‐luteal phase would exhibit a greater contribution of dry heat loss to total heat loss as compared to the early‐follicular phase during exercise in warm‐dry conditions.Seven young, recreationally active, ovulating females (3 using hormonal intrauterine devices, mean (SD), 24 (3) years, V̇O2peak 40.5 (3.4) mL kg‐1 min‐1) completed two 45‐min bouts of semi‐recumbent cycling at a low (175 W m‐2; ~40% V̇O2peak) and high (275 W m‐2; ~65% V̇O2peak) rate of metabolic heat production, interspersed by 15‐min rest, in warm‐dry conditions (30.0 (0.2) °C, (25 (9) % relative humidity) in the early‐follicular (cycle days 2‐6) and mid‐luteal phase (days 19‐23). Metabolic heat production and dry and evaporative heat loss were measured via indirect and direct calorimetry, respectively. The contribution of dry heat loss was expressed as a percentage of total heat loss. Body core temperature (esophageal, n=6) and mean skin temperature (8 sites) were measured continuously. Averages of the final 5‐min of exercise in each heat load were compared between phases using dependent, two‐tailed t‐tests.As anticipated, resting body core temperature in the mid‐luteal phase was 0.2 °C [95% CI: 0.1, 0.3] higher than in the early‐follicular phase (p&lt;0.001). Core temperature remained 0.2 °C [0.1, 0.5] higher at the low heat load (37.8 (0.2) vs. 37.6 (0.3) °C, p&lt;0.01), but initial differences in core temperature were not observed in the high heat load (38.4 (0.3) vs. 38.3 (0.4) °C, p=0.83). Skin temperature and core‐to‐skin gradient were similar between phases throughout (all p≥0.21). Total heat loss was not different between phases at the low (162 (8) vs. 162 (13) W m‐2, p=0.93) or high (255 (10) vs. 252 (7) W m‐2, p=0.39) heat loads. However, the contribution of dry heat loss to total heat loss was 3% [1, 4] greater in the mid‐luteal phase at the low heat load (20 (8) vs. 17 (9) %, p&lt;0.01). This difference was not observed at the high heat load (12 (8) vs. 10 (9) %, p=0.16).In this preliminary analysis, females in the mid‐luteal phase exhibited a higher body core temperature and greater contribution of dry heat loss to total heat loss at low exercise‐induced heat loads in warm‐dry conditions. However, these differences were not observed at higher heat loads. These data provide novel mechanistic insight into the shifts in the contribution of the main avenues of heat loss in ovulating females across the menstrual cycle.

Using amplitude-phase parameters of circadian rhythms as diagnostic markers of carbohydrate metabolism disorders

BACKGROUND: With the development of visceral obesity, against the background of insulin resistance (IR), lipo- and glucose toxicity in tissues progresses, which disrupts the metabolic balance of the body, and is the main factor in the development of type 2 diabetes mellitus (DM2). To date, a growing number of publications highlighting the role of circadian rhythms in the control of gluconeogenesis and lipogenesis. In the context of the development of DM2, the process of rhythm mismatch (desynchronosis) is increasingly mentioned, for the diagnosis of which the calculation of amplitude-phase parameters is used. Thus, the study of circadian rhythm disturbances using amplitude-phase parameters and factors influencing them is of particular interest in individuals with visceral obesity and prediabetes, since the data obtained can be used as markers for preclinical diagnosis of DM2.AIM: To identify significant differences in the parameters (amplitude, acrophase) of circadian rhythms (fasting glycemia, basal body temperature, heart rate) as markers of desynchronosis in groups without carbohydrate metabolism disorders, but with the presence of visceral obesity, prediabetes (impaired fasting glycemia, impaired glucose tolerance test) and DM2 and obesity.MATERIALS AND METHODS: The study was conducted in individuals with visceral obesity, as well as the presence of prediabetes or DM2, with a disease experience of not more than 5 years.In accordance with the study design, every 3 hours during the day, the participants made self-measurements of blood glucose at home (using individual glucometers), basal body temperature (BTT) in the armpit (using a mercury thermometer) and heart rate (HR) ( with the help of an electronic tonometer), with the fixation of the results in self-control diaries. To assess the reliability of the circadian rhythms of the studied indicators, the interpretation of chronobiological parameters (MESORa-Midline Estimating Statistic of Rhytm; amplitude; acrophase) was carried out using a single сosinor analysis.RESULTS: Of the 120 study participants, 73% were women and 27% were men. Mean age of participants was 58.6[52.2;56.7] years, BMI 31.3[29.7;33.9] and presence of visceral obesity WC 100 [93.8;104.7]. When conducting cosinor analysis, the daily rhythms of physiological indicators of fasting glycemia, BTT and heart rate differ from normal already in the group with visceral obesity without carbohydrate metabolism disorders and prediabetes, in the form of a decrease in the amplitude of daily rhythms (p&lt;0.001), with a shift in their acrophases (p &lt;0.001), no dynamics of night BBT decrease (р&lt;0.001).CONCLUSION: Integral amplitude-phase parameters of circadian rhythms of physiological parameters (fasting glycemia, basal body temperature, heart rate), as markers of desynchronosis, can be used in the presence of visceral obesity for preclinical diagnosis of prediabetes and DM2, which will have a preventive focus. This method of chronodiagnostics can be useful in health and prevention centers for people at risk of developing DM2.

Effect of handgrip exercise on QTc interval during different phases of menstrual cycle

Menopause is a major change in a women’s life, it refers to a permanent cessation of menstruation and fertility. The fast face of modern life has induced many problems like stress, anxiety, insomnia etc. associated with serious health problems. The most common disorders associated with menstruation among younger women are dysmenorrhea, pre-menstrual syndrome, menorrhagia, metrorrhagia. Aims and Objectives: To record the effect of handgrip exercise on QTc and RR interval in different phases of menstrual cycle and to compare with the baseline ecg values. The study was conducted on 40 medical (I MBBS) students from Mysore Medical College and Research Institute, Mysore. In this study a total of 40 female students aged between 17-19 years from 1st MBBS studying at Mysore Medical Collage and Research Institute, Mysore were selected as per the inclusion and exclusion criteria. Informed consent was obtained from each student. Data about the duration of previous two menstrual cycles and the days of menstrual bleeding were noted from the subjects statement. Subject monitored basal body temperature was used to identify phases of menstrual cycle. Ovulation was indicated by a sustained increase in the basal body temperature of at least 0.3°C after LH surge.

Effect of handgrip exercise on QTc interval during different phases of menstrual cycle

Introduction: Menopause is a major change in a women’s life, it refers to a permanent cessation of menstruation and fertility. The fast face of modern life has induced many problems like stress, anxiety, insomnia etc. associated with serious health problems. The most common disorders associated with menstruation among younger women are dysmenorrhea, pre-menstrual syndrome, menorrhagia, metrorrhagia. Aims and Objectives: To record the effect of handgrip exercise on QTc and RR interval in different phases of menstrual cycle and to compare with the baseline ecg values. Materials and Methods: The study was conducted on 40 medical (I MBBS) students from Mysore Medical College and Research Institute, Mysore. In this study a total of 40 female students aged between 17-19 years from 1st MBBS studying at Mysore Medical Collage and Research Institute, Mysore were selected as per the inclusion and exclusion criteria. Informed consent was obtained from each student. Data about the duration of previous two menstrual cycles and the days of menstrual bleeding were noted from the subjects statement. Subject monitored basal body temperature was used to identify phases of menstrual cycle. Ovulation was indicated by a sustained increase in the basal body temperature of at least 0.3°C after LH surge.

A one-year observational cohort study of menstrual cramps and ovulation in healthy, normally ovulating women

This is a prospective, observational community cohort study with the objective of investigating menstrual cramp occurrence related to ovulatory characteristics. Women reported cramp intensity on daily Menstrual Cycle Diary© records over one year. Ovulation and luteal phase lengths were assessed by validated Quantitative Basal Temperature© (QBT) analysis. Healthy, normal-weight, non-smoking community dwelling premenopausal women ages 21–41 years with two consecutive, normally ovulatory, normal-length menstrual cycles were enrolled. All 53 women, with 13.6 ± 2.8 cycles per woman, reported at least one cramp episode of median intensity 1.5 [0–4 scale; range 1.0–3.5], and 2.2 days’ [range 1.0–10.2] duration. Within the 49 women who experienced all ovulatory cycle types (normal, short luteal length [SLL < 10 days] and anovulatory), median cramp intensity was greater in normal-length cycles having subclinical ovulatory disturbances (SLL and anovulatory; median 1.4 [range 0.0–2.8]) than in normally ovulatory cycles (median 1.2 [range 0.0–2.3]) (P = 0.023). Cramp Scores did not differ by ovulatory status within the 19 women having both normally ovulatory and anovulatory cycles (P = 0.222). Within-woman 1-year Cramp Scores were not different in anovulatory and normally ovulatory menstrual cycles but were more intense with ovulatory disturbances.

The topographic signature of temperature-controlled rheological transitions in an accretionary prism

Abstract. The local topographic slope of the accretionary prism is often used together with the critical taper theory to determine the effective friction on subduction megathrust. In this context, extremely small topographic slopes associated with extremely low effective basal friction (μ≤0.05) can be interpreted either as seismically locked portions of megathrust, which deforms episodically at dynamic slip rates or as a viscously creeping décollement. Existing mechanical models of the long-term evolution of accretionary prism, sandbox models, and numerical simulations alike, generally do not account for heat conservation nor for temperature-dependent rheological transitions. Here, we solve for advection–diffusion of heat with imposed constant heat flow at the base of the model domain. This allows the temperature to increase with burial and therefore to capture how the brittle–ductile transition and dehydration reactions within the décollement affect the dynamic of the accretionary prism and its topography. We investigate the effect of basal heat flow, shear heating, thermal blanketing by sediments, and the thickness of the incoming sediments. We find that while reduction of the friction during dewatering reactions results as expected in a flat segment often in the forearc, the brittle–ductile transition results unexpectedly in a local increase of topographic slope by decreasing internal friction. We show that this counterintuitive backproduct of the numerical simulation can be explained by the onset of internal ductile deformation in between the active thrusts. Our models, therefore, imply significant viscous deformation of sediments above a brittle décollement, at geological rates, and we discuss its consequences in terms of interpretation of coupling ratios at subduction megathrust. We also find that, with increasing burial and ductile deformation, the internal brittle deformation tends to be accommodated by backthrusts until the basal temperature becomes sufficient to form a viscous channel, parallel to the décollement, which serves as the root to a major splay fault and its backthrust and delimits a region with a small topographic slope. Morphologic resemblances of the brittle–ductile and ductile segments with forearc high and forearc basins of accretionary active margins, respectively, allow us to propose an alternative metamorphic origin of the forearc crust in this context.

Novel Technique for Confirmation of the Day of Ovulation and Prediction of Ovulation in Subsequent Cycles Using a Skin-Worn Sensor in a Population With Ovulatory Dysfunction: A Side-by-Side Comparison With Existing Basal Body Temperature Algorithm and Vaginal Core Body Temperature Algorithm.

Objective: Determine the accuracy of a novel technique for confirmation of the day of ovulation and prediction of ovulation in subsequent cycles for the purpose of conception using a skin-worn sensor in a population with ovulatory dysfunction. Methods: A total of 80 participants recorded consecutive overnight temperatures using a skin-worn sensor at the same time as a commercially available vaginal sensor for a total of 205 reproductive cycles. The vaginal sensor and its associated algorithm were used to determine the day of ovulation, and the ovulation results obtained using the skin-worn sensor and its associated algorithm were assessed for comparative accuracy alongside a number of other statistical techniques, with a further assessment of the same skin-derived data by means of the “three over six” rule. A number of parameters were used to divide the data into separate comparative groups, and further secondary statistical analyses were performed. Results: The skin-worn sensor and its associated algorithm (together labeled “SWS”) were 66% accurate for determining the day of ovulation (±1 day) or the absence of ovulation and 90% accurate for determining the fertile window (ovulation day ±3 days) in the total study population in comparison to the results obtained from the vaginal sensor and its associated algorithm (together labeled “VS”). Conclusion: SWS is a useful tool for confirming the fertile window and absence of ovulation (anovulation) in a population with ovulatory dysfunction, both known and determined by means of the timing of ovulation. The body site where the skin-worn sensor was worn (arm or wrist) did not appear to affect the accuracy. Prior diagnosis of known causes of ovulatory dysfunction appeared to affect the accuracy to a lesser extent than those cycles grouped into late ovulation and “early and normal ovulation” groups. SWS is a potentially useful tool for predicting ovulation in subsequent cycles, with greater accuracy obtained for the “normal ovulation” group.

Coffee pest severity by agrometeorological models in subtropical climate.

This study aimed to estimate the number of generations and cycle duration of the southern red mite, coffee berry borer, and coffee leaf miner using the thermal index to assist in controlling these main coffee pests in the state of Paraná, Brazil. The data of maximum and minimum air temperature (°C) and precipitation (mm) of all municipalities in the state from 1984 to 2018 were collected from the National Aeronautics and Space Administration/Prediction of Worldwide Energy Resources (NASA/POWER). The reference evapotranspiration was estimated using the (Camargo Campinas IAC Boletim 116:9, 1971) method and the water balance was calculated using the method of ( Thornthwaite C, Mather J (1955) The water balance publications in climatology, 8 (1). DIT, Laboratory of climatology, Centerton, NJ, USA). The basal temperature of each pest minus the average temperature of the years was used to calculate the degrees-day, the duration of the pest cycle, and the number of generations per year. The influence of altitude on the development of coffee pests was measured using the Pearson correlation. The thermal index is able to estimate the damage caused by coffee pests in the state of Pará, Brazil. Coffee pests show greater severity in the north of Paraná, in the regions with the highest temperatures. It is the same region that concentrates most of the coffee production of the state. The results of the life cycle and number of generations were interpolated for the entire state using the kriging method. Coffee pests showed the highest severity in the north region of the state of Paraná, more specifically in the Northwest, North Central, and West Central mesoregions. These regions have concentrated most of the state's coffee production. Mesoregions with the highest coffee production in the state showed higher susceptibility to coffee pests. Altitude showed a high correlation (r > 0.6) with the cycle variability and number of generations of coffee pests. The average cycles of the coffee berry borer, coffee leaf miner, and southern red mite are 24.13 (± 8.34), 45.64 (± 18.61), and 21.51 (± 3.51) days, respectively. The average annual generation was 16.67 (± 4.77), 9.02 (± 2.75), and 17.32 (± 2.63) generations, for the coffee berry borer, the coffee red mite, and the southern red mite, respectively.