Fractional order control for the temperature loop in a chemical reactor

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HIL real-time simulation of a digital fractional order PI controller for time delay processes

Fractional order control has been used extensively in the last decade for controlling various types of processes. Several design approaches have been proposed so far, the closed loop performance results obtained being tested using different simulation conditions. The hardware-in-the-loop (HIL) real-time simulation offers a more reliable method for evaluating the closed loop performance of such controllers prior to their actual implementation on the real processes, such HIL simulation being highly suitable especially for complex, hazardous processes in which human and equipment errors should be avoided. The present paper proposes a hardware-in-the-loop real-time simulation setting for a digital fractional order PI controller in a Smith Predictor structure. The designed control strategy and fractional order controller is then tested under nominal and uncertain conditions, considering a time delay process

Sexual dysfunction in women with PCOS:a case control study

STUDY QUESTIONWhat is the relationship of sex steroid levels with sexual function in women with and without polycystic ovary syndrome (PCOS)?SUMMARY ANSWERWomen with PCOS reported more sexual dysfunction and more sexual distress compared to those without PCOS, but only few and weak associations between androgen levels and sexual function were observed.WHAT IS KNOWN ALREADYThe literature shows that women with PCOS report lower levels of sexual function and sexual satisfactionand more sexual distress. Contributing factors seem to be obesity, alopecia, hirsutism, acne, infertility, anxiety, depression, and low self-esteem. In women with PCOS clinical and/or biochemical hyperandrogenism is common; its relationship with sexualfunction is, however, inconclusive.STUDY DESIGN, SIZE, DURATIONThis observational prospective case control study with 135 women (68 PCOS, 67 control) was conductedfrom March 2017 until March 2020.PARTICIPANTS/MATERIALS, SETTING, METHODSHeterosexual women with and without PCOS, aged 18–40 years, in a steady relationshipand without any comorbidities, underwent an extensive medical and endocrine screening using liquid chromatography-tandem mass spectrometry and validated sexual function questionnaires.MAIN RESULTS AND THE ROLE OF CHANCEWomen with PCOS reported significantly lower sexual function (Female Sexual Function Index (FSFI) P < 0.001, partial η2 = 0.104), higher levels of sexual distress (Female Sexual Distress Scale-Revised P < 0.001, partial η2 = 0.090), and they more often complied with the definition of sexual dysfunction (41.2% vs 11.9%, P < 0.001, Phi V = 0.331) and clinical sexual distress (51.5% vs 19.4%, P < 0.001, Phi V = 0.335). Regression analysis adjusted for confounders showed only few and weak associations between androgen levels and sexual function, with each model explaining a maximum of 15% sexual function. Following significant Group × Hormone interactions, analyses for both groups separately showed no significant associations in the PCOS group. The control group showed only weak negative associations between testosterone and FSFI pain (β = −6.022, P = 0.044, Adj R2 = 0.050), between FAI and FSFI orgasm (β = −3.360, P = 0.023, Adj R2 = 0.049) and between androstenedione and clinical sexual distress (β = −7.293, P = 0.036, exp(β) = 0.001).LIMITATIONS, REASONS FOR CAUTIONThe focus of the study on sexual functioning potentially creates selection bias. Possibly women with more severe sexual disturbances did or did not choose to participate. Differences between women with PCOS and controls in relationship duration and hormonal contraceptive use might have skewed the sexual function outcomes.WIDER IMPLICATIONS OF THE FINDINGSSexual function is impaired in women with PCOS. However, endocrine perturbations seem to have minimal direct impact on sexual function. Addressing sexuality and offering psychosexual counseling is important in the clinical care for women with PCOS

Surface Instability in Windblown Sand

We investigate the formation of ripples on the surface of windblown sand based on the one-dimensional model of Nishimori and Ouchi [Phys. Rev. Lett. 71, 197 (1993)], which contains the processes of saltation and grain relaxation. We carry out a nonlinear analysis to determine the propagation speed of the restabilized ripple patterns, and the amplitudes and phases of their first, second, and third harmonics. The agreement between the theory and our numerical simulations is excellent near the onset of instability. We also determine the Eckhaus boundary, outside which the steady ripple patterns are unstable.Comment: 23 pages, 8 figure

Adverse wind conditions during northward Sahara crossings increase the in-flight mortality of Black-tailed Godwits

Long-distance migratory flights are predicted to be associated with higher mortality rates when individuals encounter adverse weather conditions. However, directly connecting environmental conditions experienced in-flight with the survival of migrants has proven difficult. We studied how the in-flight mortality of 53 satellite-tagged Black-tailed Godwits (Limosa limosa limosa) during 132 crossings of the Sahara Desert, a major geographical barrier along their migration route between The Netherlands and sub-Saharan Africa, is correlated with the experienced wind conditions and departure date during both southward and northward migration. We show that godwits experienced higher wind assistance during southward crossings, which seems to reflect local prevailing trade winds. Critically, we found that fatal northward crossings (15 deaths during 61 crossings) were associated with adverse wind conditions. Wind conditions during migration can thus directly influence vital rates. Changing wind conditions associated with global change may thus profoundly influence the costs of long-distance migration in the future

Individual Black-tailed Godwits do not stick to single routes:A hypothesis on how low population densities might decrease social conformity

The miniaturization of tracking devices is now rapidly increasing our knowledge on the spatiotemporal organization of seasonal migration. So far, most studies aimed at understanding within- and between-individual variation in migratory routines focus on single populations. This has also been the case for continental Black-tailed Godwits Limosa l. limosa (hereafter Godwits), with most work carried out on individuals from the Dutch breeding population, migrating in relatively large numbers in the westernmost part of the range. Here we report the migratory timing and routes of four adult individuals of the same subspecies from the low-density population in eastern Poland and compare this with previously published data on Godwits breeding in The Netherlands. During northward migration, the birds from Poland departed and arrived later from their wintering and breeding grounds. However, on southward migration the Polish breeding Godwits departed earlier, but arrived one month later than the Dutch birds on their wintering grounds in sub-Saharan Africa. Despite the small sample size of tracked birds from Poland, we find a significantly higher between-individual variation in timing during southward migration in Polish Godwits as compared to the Dutch Godwits. Furthermore, not only did migratory routes differ, but the few Polish Godwits tracked showed a higher level of between- and within-individual variation in route choice during both southward and northward migration. To explain this remarkable discrepancy, we propose that the properties of transmission of social information may be different between Godwits from a high-density population (i.e. the one in The Netherlands) and a low-density population (in Poland) and that this leads to different levels of canalization. To examine this hypothesis, future studies should not only follow individuals from an early age onwards, but also quantify and experimentally manipulate their social environments during migration

Discussing sexual health in spinal care

Abstract BACKGROUND: The possible detrimental effects of spinal disease on sexual health are widely recognized; however, it is not known to what extent neurosurgeons discuss this topic with their patients. The aim of this study is to identify knowledge, attitude and practice patterns of neurosurgeons counseling their patients about sexual health. METHODS: All members of the Dutch Association of Neurosurgery (neurosurgeons and residents) were sent a questionnaire addressing their attitudes, knowledge and practice patterns regarding discussing sexual health. RESULTS: Response rate was 62 % with 89 questionnaires suitable for analysis. The majority of participants (83 %) were male; mean age, 42.4 years. The mean experience in neurosurgical practice was 9 years. Respondents assumed that in 34 % of their patients, sexual health was affected due to spinal disease. The majority of respondents (64 %) stated that responsibility for discussing sexual health lies (partly) with the neurosurgeon; however, 73 % indicated to (almost) never do this. The main reasons for not discussing sexual health were patients' old age (42 %), lack of knowledge (38 %) and lack of patients' initiative to bring up the subject (36 %). Twenty-six percent indicated lack of time as a reason. There was no evidence for gender or doctor's age discordance as important barriers. Fifty percent of participants wished to gain more knowledge on discussing sexual health with patients. CONCLUSION: This study shows that despite high prevalence of sexual dysfunction (SD) in spinal patients, counseling about sexual health is not often done in neurosurgical care. More training on sexual health counseling early in the residency program seems critical. By initiating the discussion, clinicians who deal with spinal patients have the potential to detect sexual dysfunction (SD) and to refer adequately when necessary, thereby improving overall quality of life of their patients. KEYWORDS: Cauda equina syndrome; Counseling; Patient care; Sexual dysfunction; Spinal cord injury GynecologyCervix cance

Migration route, stopping sites, and non-breeding destinations of adult Black-tailed Godwits breeding in southwest Fryslân, The Netherlands

In this paper, we extend our understanding of the migration of Black-tailed Godwits (Limosa limosa limosa) by describing: (1) the orientation and geographic locations of individual migratory routes and (2) the spatial distribution of godwits across seasons and years. We accomplish this using satellite-tracking data from 36 adult godwits breeding in the 200-ha Haanmeer polder in The Netherlands, from 2015 to 2018. During both southward and northward migration, godwits used a narrow migratory corridor along which most individuals made stops within a network of sites, especially the Bay of Biscay, France and Doñana, Spain. Most sites were used consistently by the same individuals across years. However, sites in Morocco were used during northward migration by 75% of individuals, but not revisited by the same individual across years. After southward migration, a small proportion (15%) of godwits spent the entire non-breeding period north of the Sahara, but most (85%) crossed the Sahara and spent at least part of the non-breeding season among seven coastal sites in West Africa and one site in the Inner Niger Delta. Although site-use patterns varied among individuals, individuals showed high site fidelity and were consistent in the number of sites they used from year to year. The considerable differences in the spatial distribution of individuals that breed within a kilometre of one another raise questions about the causes and consequences of individual migratory differences. We discuss that full annual cycle tracking of juveniles from birth to adulthood is needed to understand the source of these individual differences. Our results on the spatial distribution of godwits throughout their annual cycle lay an important foundation of information that can be used to help conserve this declining species