350 research outputs found

    The phenotype and genotype of adult obstructive sleep apnoea/hypopnoea syndrome

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldObstructive sleep apnoea/hypopnoea syndrome (OSAHS) is a common condition affecting approximately 2-4% of the middle-aged population. A hereditary component to the condition has long been recognised but its genetic basis has been difficult to elucidate. Progress in determining the genotype of OSAHS is hampered by the lack of a consistent definition of phenotype and the large environmental influences on its expression. "Intermediate phenotypes", such as craniofacial structure, obesity and upper airway control, have been utilised. Multiple gene polymorphisms have been explored in association with the latter, as well as with the sequelae of OSAHS, such as hypertension and increased insulin resistance. To date, two genome-wide scans have identified potential regions that may be of interest in further defining the intermediate phenotypes. The present paper focuses on human studies with an update of the most recent work in the area, including a short discussion on methods of genetic studies

    Energy balance in irrigated wheat in the Cerrados Region of central Brazil.

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    To evaluate the water requirements for Irrigated wheat, a mlcrometeorological study was conducted during the dry seasons of 1982 and 1983 at the Cerrados Agricultural Research Center, Brasilia-DF, BraziL The crop was Irrigated when the soU water potential at 5 cm reached-60 to -7OJIkg. Bowen ratio measurements were made on an hourly basls during the entire crop season, Total amount of water evapotranspired during the crop cycle and the energy balance terms varied year to year due to regional advection; ln 1982,a Iess advective year, the total amount of water evapotranspired was 345 mm, with approximately 80% of the net radlation dlsslpated as latent heat, 13% as a sensible heat and 7% as soU heat after the crop obtalned a Leaf Area lndex (LAI) of 1.5. ln 1983, when advection was greater than 1982, total water evapotranspired Increased to 385mm. The partitloning of energy was similar to 1982 during periods of title or no advecnon, However, during periods of Intense advection, latent heat was greater. In net radlation partitioning. Although regional advection Increased the water used by the crop, Irrigation scheduling based on soíl tensiometers was considered adequate and eflicient due to the low values of the Bowen ratio obtalned. Um estudo núcrometeorológico para avaliar a demanda hídrica do trigo Irrigado foi conduzido nasestações secas de 1982 e 1983 no Centro de Pesquisa Agricola dos Cerrados, Brasilia-DF, Brasil A cultura foi Irrigada quando o potencial de água no solo a 5 cm atinriu -60 a -70 JIkg. Durante todo o ciclo da cultura medidas da razão de Bowen foram feitas numa base horária. A quantidade total de água evapotranspirada durante todo ciclo da cultura e o balanço energético variaram entre os anos devido à advecção regional; em 1982, um ano menos advectivo, a quantidade total de água evapotranspirada foi de 345 mm, sendo 80% da radiação líquida dissipada como calor latente, 13% como calor sensível e 7% como calor do solo após a cultura ter atingido um Índice de Área Foliar (IAF) de 1.5. Em 1983, quando a advecção foi maior que em 1982, a quantidade total de água evapotranspirada aumentou para 385 mm. A partição de energia foi similar à 1982 durante periodos de pouca ou nenhuma advecção. Entretanto durante periodos de Intensa advecção, o calor latente representou a maior parte da radiação líquida. Apesar da advecção regional aumentar o consumo de água da cultura, programação da irrigação baseada em tensiometros foi considerada adequada e eficiente devido aos baixos valores da razão de Bowen obtidos.Nº especial

    Energy balance in irrigated wheat in the Cerrados Region of central Brazil.

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    Um estudo micrometeorológico para avaliar a demanda hídrica do trigo irrigado foi conduzido nas estacões secas de 1982 e 1983 no Centro de Pesquisa Agrícola dos Cerrados, Brasilia-DF, Brasil. A cultura foi irrigada quando o potencial de água no solo a 5 cm atingiu -60 a -70 J/kg.Durante todo o ciclo da cultura medidas da razão de Bowen foram feitas numa base horaria. A quantidade total de água evapotranspirada durante todo ciclo da cultura e o balanco energético variaram entre os anos devido a advecção regional; em 1982, um ano menos advectivo, a quantidade total de água evapotranspirada foi de 345 mm, sendo 80% da radiação liquida dissipada como calor latente, 13% como calor sensível e 7% como calor do solo apos a cultura ter atingido um Índice de Área Foliar (IAF) de 1.5. Em 1983, quando a advecção foi maior que em 1982, a quantidade total de água evapotranspirada aumentou para 385mm. A partição de energia foi similar a 1982 durante períodos de pouca ou nenhuma advecção. Entretanto durante períodos de intensa advecção, o calor latente representou a maior parte da radiação liquida. Apesar da advecção regional aumentar o consumo de água da cultura, programação da irrigação baseada em tensiômetro foi considerada adequada e eficiente devido aos baixos valores da razão de Bowen obtidos

    Sex differences in obstructive sleep apnoea

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    Obstructive sleep apnoea (OSA) and obstructive sleep apnoea/hypopnoea syndrome (OSAHS) have long been considered predominantly male-related conditions. The clinical presentation of sleep disordered breathing in females differs from males and can vary with age and physiological status, e.g. menopause and pregnancy. Overall, females appear to be more symptomatic, with lower apnoea–hypopnoea index scores compared to males. Furthermore, they appear to have more prolonged partial upper airway obstruction, and may report insomnia as a symptom of OSAHS more frequently. As a consequence of these differences in clinical presentation, females with sleep disordered breathing are often underdiagnosed and undertreated compared to males. This review is aimed at discussing the epidemiology, clinical presentation, pathophysiology and hormonal and metabolic differences in females who present with OSA/OSAHS in comparison to males

    Trauma Immediately Preceding REM-Behavior Disorder:A Valuable Prognostic Marker?

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    Background: The definition of rapid eye movement (REM) sleep behavior disorder (RBD) has varied over the years. Rapid eye movement sleep behavior disorder can be considered isolated or idiopathic or can occur in the context of other disorders, including trauma-associated sleep disorder (TSD) and overlap parasomnia. However, whether trauma in RBD carries any prognostic specificity is currently unknown. Study Objectives: To test the hypothesis that RBD secondary to trauma is less likely to result in the development of neurodegeneration compared to idiopathic RBD (iRBD) without trauma in the general population. Methods: A retrospective cohort study of 122 consecutive RBD patients (103 males) at two tertiary sleep clinics in Europe between 2005 and 2020 was studied. Patients were diagnosed as having iRBD by video polysomnography (vPSG) and had a semi-structured interview at presentation, including specifically eliciting any history of trauma. Patients with secondary RBD to recognized causes were excluded from the study. Patients with iRBD were categorized into three groups according to reported trauma history: (1) No history of trauma, (2) traumatic experience at least 12 months prior to RBD symptom onset, and (3) traumatic experience within 12 months of RBD symptom onset. Idiopathic RBD duration was defined as the interval between estimated onset of RBD symptoms and last hospital visit or death. Follow-up duration was defined as the interval between iRBD diagnosis and last hospital visit or death. Results: In a follow-up period of up to 18 years, no patient who experienced trauma within 12 months preceding their iRBD diagnosis received a diagnosis of a neurodegenerative disorder (n = 35), whereas 38% of patients without trauma within the 12 months of symptom onset developed a neurodegenerative illness. These patients were also significantly more likely to have a family history of α-synucleinopathy or tauopathy. Conclusions: The development of RBD within 12 months of experiencing a traumatic life event, indistinguishable clinically from iRBD, did not lead to phenoconversion to a neurodegenerative disorder even after 18 years (mean follow up 6 years). We suggest that a sub-type of RBD be established and classified as secondary RBD due to trauma. Additionally, we advocate that a thorough psychological and trauma history be undertaken in all patients presenting with dream enactment behaviors (DEB)

    Preoperative and perioperative use of levosimendan in cardiac surgery: European expert opinion

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    In cardiac surgery, postoperative low cardiac output has been shown to correlate with increased rates of organ failure and mortality. Catecholamines have been the standard therapy for many years, although they carry substantial risk for adverse cardiac and systemic effects, and have been reported to be associated with increased mortality. On the other hand, the calcium sensitiser and potassium channel opener levosimendan has been shown to improve cardiac function with no imbalance in oxygen consumption, and to have protective effects in other organs. Numerous clinical trials have indicated favourable cardiac and non-cardiac effects of preoperative and perioperative administration of levosimendan. A panel of 27 experts from 18 countries has now reviewed the literature on the use of levosimendan in on-pump and off-pump coronary artery bypass grafting and in heart valve surgery. This panel discussed the published evidence in these various settings, and agreed to vote on a set of questions related to the cardioprotective effects of levosimendan when administered preoperatively, with the purpose of reaching a consensus on which patients could benefit from the preoperative use of levosimendan and in which kind of procedures, and at which doses and timing should levosimendan be administered. Here, we present a systematic review of the literature to report on the completed and ongoing studies on levosimendan, including the newly commenced LEVO-CTS phase III study (NCT02025621), and on the consensus reached on the recommendations proposed for the use of preoperative levosimendan

    An evaluation of four crop : weed competition models using a common data set

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    To date, several crop : weed competition models have been developed. Developers of the various models were invited to compare model performance using a common data set. The data set consisted of wheat and Lolium rigidum grown in monoculture and mixtures under dryland and irrigated conditions. Results from four crop : weed competition models are presented: ALMANAC, APSIM, CROPSIM and INTERCOM. For all models, deviations between observed and predicted values for monoculture wheat were only slightly lower than for wheat grown in competition with L. rigidum, even though the workshop participants had access to monoculture data while parameterizing models. Much of the error in simulating competition outcome was associated with difficulties in accurately simulating growth of individual species. Relatively simple competition algorithms were capable of accounting for the majority of the competition response. Increasing model complexity did not appear to dramatically improve model accuracy. Comparison of specific competition processes, such as radiation interception, was very difficult since the effects of these processes within each model could not be isolated. Algorithms for competition processes need to be modularized in such a way that exchange, evaluation and comparison across models is facilitated

    An evaluation of four crop : weed competition models using a common data set

    Get PDF
    To date, several crop : weed competition models have been developed. Developers of the various models were invited to compare model performance using a common data set. The data set consisted of wheat and Lolium rigidum grown in monoculture and mixtures under dryland and irrigated conditions. Results from four crop : weed competition models are presented: ALMANAC, APSIM, CROPSIM and INTERCOM. For all models, deviations between observed and predicted values for monoculture wheat were only slightly lower than for wheat grown in competition with L. rigidum, even though the workshop participants had access to monoculture data while parameterizing models. Much of the error in simulating competition outcome was associated with difficulties in accurately simulating growth of individual species. Relatively simple competition algorithms were capable of accounting for the majority of the competition response. Increasing model complexity did not appear to dramatically improve model accuracy. Comparison of specific competition processes, such as radiation interception, was very difficult since the effects of these processes within each model could not be isolated. Algorithms for competition processes need to be modularized in such a way that exchange, evaluation and comparison across models is facilitated

    Insomnia symptoms combined with nocturnal hypoxia associate with cardiovascular comorbidity in the European sleep apnea cohort (ESADA)

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    Purpose: The aim of the current study was to further investigate the concept of previously reported high occurrence of comorbidities in obstructive sleep patients (OSA) with insomnia-like symptoms. We hypothesized that this finding at least partly is mediated by nocturnal hypoxia. Moreover, we speculated that the spectrum of the clinical OSA phenotypes differs between European geographical regions.Methods: Cohort of the European Sleep Apnea Database (n = 17,325; 29.9% females) was divided into five subcohorts according to geographical region (North, East, South, West, Central) and further into four clinical presentation phenotypes based on daytime symptoms (EDS) and characteristics suggestive of insomnia.Results: The insomnia phenotype (alone or together with EDS) dominated in all European regions. Isolated insomnia, however, was less common in the West. Insomnia phenotype was associated with the highest proportion of cardiovascular comorbidity (51.7% in the insomnia vs. 43.9% in the EDS type). Measures of nocturnal hypoxemia were independently associated with cardiovascular comorbidity in phenotypes with insomnia-like symptoms. The burden of comorbidities was high across all geographical regions and clinical phenotypes. Regional differences were clinically relevant for age (48 vs. 54 years), BMI (29 vs. 34 kg/m2), and ODI (15 vs. 32/h).Conclusion: High prevalence of particularly cardiovascular comorbidity among patients with insomnia-like symptoms was linked to nocturnal hypoxemia. Considerable differences in clinical presentation were found among OSA patients across Europe. Our data underline that physicians should ask their patients with suspected OSA also for insomnia symptoms. It remains to be explored if a reduction of nocturnal hypoxemia predicts the improvement of insomnia symptoms.</p

    Ultrafast Hole Trapping and Relaxation Dynamics in p-Type CuS Nanodisks

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    CuS nanocrystals are potential materials for developing low-cost solar energy conversion devices. Understanding the underlying dynamics of photoinduced carriers in CuS nanocrystals is essential to improve their performance in these devices. In this work, we investigated the photoinduced hole dynamics in CuS nanodisks (NDs) using the combination of transient optical (OTA) and X-ray (XTA) absorption spectroscopy. OTA results show that the broad transient absorption in the visible region is attributed to the photoinduced hot and trapped holes. The hole trapping process occurs on a subpicosecond time scale, followed by carrier recombination (~100 ps). The nature of the hole trapping sites, revealed by XTA, is characteristic of S or organic ligands on the surface of CuS NDs. These results not only suggest the possibility to control the hole dynamics by tuning the surface chemistry of CuS but also represent the first time observation of hole dynamics in semiconductor nanocrystals using XTA
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