131 research outputs found

    Decadal and multi-decadal variability of Labrador Sea Water in the north-western North Atlantic Ocean derived from tracer distributions: Heat budget, ventilation, and advection

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    Time series of profiles of potential temperature, salinity, dissolved oxygen, and planetary potential vorticity at intermediate depths in the Labrador Sea, the Irminger Sea, and the Iceland Basin have been constructed by combining the hydrographic sections crossing the sub-arctic gyre of the North Atlantic Ocean from the coast of Labrador to Europe, occupied nearly annually since 1990, and historic hydrographic data from the preceding years since 1950. The temperature data of the last 60 years mainly reflect a multi-decadal variability, with a characteristic time scale of about 50 years. With the use of a highly simplified heat budget model it was shown that this long-term temperature variability in the Labrador Sea mainly reflects the long-term variation of the net heat flux to the atmosphere. However, the analysis of the data on dissolved oxygen and planetary potential vorticity show that convective ventilation events, during which successive classes of Labrador Sea Water (LSW) are formed, occurring on decadal or shorter time scales. These convective ventilation events have performed the role of vertical mixing in the heat budget model, homogenising the properties of the intermediate layers (e.g. temperature) for significant periods of time. Both the long-term and the near-decadal temperature signals at a pressure of 1500 dbar are connected with successive deep LSW classes, emphasising the leading role of Labrador Sea convection in running the variability of the intermediate depth layers of the North Atlantic. These signals are advected to the neighbouring Irminger Sea and Iceland Basin. Advection time scales, estimated from the 60 year time series, are slightly shorter or of the same order as most earlier estimates, which were mainly based on the feature tracking of the spreading of the LSW(94) class formed in the period 1989-1994 in the Labrador Sea

    Deep convection in the Irminger Sea observed with a dense mooring array

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    Deep convection is a key process in the Atlantic Meridional Overturning Circulation, but because it acts at small scales, it remains poorly resolved by climate models. The occurrence of deep convection depends on weak initial stratification and strong surface buoyancy forcing, conditions that are satisfied in only a few ocean basins. In 2014, one of the Ocean Observatories Initiative (OOI) global arrays was installed close to the Central Irminger Sea (CIS) and the Long-term Ocean Circulation Observations (LOCO) moorings in the central Irminger Sea. These programs’ six moorings are located in the center of an area of deep convection and are distributed within a 50 km radius, thus offering detailed insight into spatial differences during the strong convection events that occurred during the winters of 2014/2015 and 2015/2016. Deep mixed layers, down to approximately 1,600 m, formed during both winters. The properties of the convectively renewed water mass at each mooring converge to a common temperature and salinity before restratification sets in at the end of winter. The largest differences in onset (or timing) of convection and restratification are seen between the northernmost and southernmost moorings. High-resolution atmospheric reanalysis data show there is higher atmospheric forcing at the northernmost mooring due to a more favorable position with respect to the Greenland tip jet. Nevertheless, earlier onset, and more continuous cooling and deepening of mixed layers, occurs at the southernmost mooring, while convection at the northern mooring is frequently interrupted by warm events. We propose that these warm events are associated with eddies and filaments originating from the Irminger Current off the coast of Greenland and that convection further south benefits from cold inflow from the southwest

    Rotterdam Aphasia Therapy Study (RATS) - 3: " The efficacy of intensive cognitive-linguistic therapy in the acute stage of aphasia"; design of a randomised controlled trial

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    Background: Aphasia is a severely disabling condition occurring in 20 to 25% of stroke patients. Most patients with aphasia due to stroke receive speech and language therapy. Methodologically sound randomised controlled trials investigating the effect of specific interventions for patients with aphasia following stroke are scarce.

    Systematic Review and Meta-Analysis of Preterm Birth and Later Systolic Blood Pressure

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    Lower birth weight because of fetal growth restriction is associated with higher blood pressure later in life, but the extent to which preterm birth ( <37 completed weeks' gestation) or very low birth weight ( <1500 g) predicts higher blood pressure is less clear. We performed a systematic review of 27 observational studies that compared the resting or ambulatory systolic blood pressure or diagnosis of hypertension among children, adolescents, and adults born preterm or very low birth weight with those born at term. We performed a meta-analysis with the subset of 10 studies that reported the resting systolic blood pressure difference in millimeters of mercury with 95% CIs or SEs. We assessed methodologic quality with a modified Newcastle-Ottawa Scale. The 10 studies were composed of 1342 preterm or very low birth weight and 1738 term participants from 8 countries. The mean gestational age at birth of the preterm participants was 30.2 weeks (range: 28.8-34.1 weeks), birth weight was 1280 g (range: 1098-1958 g), and age at systolic blood pressure measurement was 17.8 years (range: 6.3-22.4 years). Former preterm or very low birth weight infants had higher systolic blood pressure than term infants (pooled estimate: 2.5 mm Hg [95% CI: 1.7-3.3 mm Hg]). For the 5 highest quality studies, the systolic blood pressure difference was slightly greater, at 3.8 mm Hg (95% CI: 2.6-5.0 mm Hg). We conclude that infants who are born preterm or very low birth weight have modestly higher systolic blood pressure later in life and may be at increased risk for developing hypertension and its sequela

    The course of health-related quality of life in the first 2 years after a diagnosis of head and neck cancer:the role of personal, clinical, psychological, physical, social, lifestyle, disease-related, and biological factors

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    Purpose: The aim of this prospective cohort study was to estimate the relationship between the course of HRQOL in the first 2 years after diagnosis and treatment of head and neck cancer (HNC) and personal, clinical, psychological, physical, social, lifestyle, HNC-related, and biological factors. Methods: Data were used from 638 HNC patients of the NETherlands QUality of life and BIomedical Cohort study (NET-QUBIC). Linear mixed models were used to investigate factors associated with the course of HRQOL (EORTC QLQ-C30 global quality of life (QL) and summary score (SumSc)) from baseline to 3, 6, 12, and 24 months after treatment. Results: Baseline depressive symptoms, social contacts, and oral pain were significantly associated with the course of QL from baseline to 24 months. Tumor subsite and baseline social eating, stress (hyperarousal), coughing, feeling ill, and IL-10 were associated with the course of SumSc. Post-treatment social contacts and stress (avoidance) were significantly associated with the course of QL from 6 to 24 months, and social contacts and weight loss with the course of SumSc. The course of SumSc from 6 to 24 months was also significantly associated with a change in financial problems, speech problems, weight loss, and shoulder problems between baseline and 6 months. Conclusion: Baseline clinical, psychological, social, lifestyle, HNC-related, and biological factors are associated with the course of HRQOL from baseline to 24 months after treatment. Post-treatment social, lifestyle, and HNC-related factors are associated with the course of HRQOL from 6 to 24 months after treatment.</p

    The course of swallowing problems in the first 2 years after diagnosis of head and neck cancer

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    Introduction: Head and neck cancer (HNC) and its treatment often negatively impact swallowing function. The aim was to investigate the course of patient-reported swallowing problems from diagnosis to 3, 6, 12, and 24 months after treatment, in relation to demographic, clinical, and lifestyle factors. Methods: Data were used of the Netherlands Quality of Life and Biomedical Cohort Study in head and neck cancer research (NET-QUBIC). The primary outcome measures were the subscales of the Swallowing Quality of Life Questionnaire (SWAL-QOL). Linear mixed-effects models (LMM) were conducted to investigate changes over time and associations with patient, clinical, and lifestyle parameters as assessed at baseline. Results: Data were available of 603 patients. There was a significant change over time on all subscales. Before treatment, 53% of patients reported swallowing problems. This number increased to 70% at M3 and decreased to 59% at M6, 50% at M12, and 48% at M24. Swallowing problems (i.e., longer eating duration) were more pronounced in the case of female, current smoking, weight loss prior to treatment, and stage III or IV tumor, and were more prevalent at 3 to 6 months after treatment. Especially patients with an oropharynx and oral cavity tumor, and patients receiving (C)RT following surgery or CRT only showed a longer eating duration after treatment, which did not return to baseline levels. Conclusion: Half of the patients with HNC report swallowing problems before treatment. Eating duration was associated with sex, smoking, weight loss, tumor site and stage, and treatment modality, and was more pronounced 3 to 6 months after treatment

    Sleep quality trajectories from head and neck cancer diagnosis to six months after treatment

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    Objectives: Patients with head and neck cancer (HNC) often report disturbances in their sleep quality, impairing their quality of life. This study aims to examine the trajectories of sleep quality from diagnosis up to 6-month after treatment, as well as the pre-treatment risk factors for poor sleep trajectories. Materials and Methods: Sleep quality (Pittsburgh sleep quality index) was measured shortly after diagnosis (pre-treatment), and at 3 and 6 months after finishing treatment. Patients were categorized into 5 trajectory groups. We examined the association of sleep quality trajectories with sociodemographic and clinical characteristics, coping style, HNC symptoms, and psychological distress. Results: Among 412 included patients, about a half either had a persistent good sleep (37.6%) or an improving (16.5%) trajectory. About a third had a persistent poor sleep (21.8%) or worsening (10.9%) sleep trajectory. The remaining patients (13.1%), alternated between good and poor sleep. Using persistent good sleep as a reference outcome, persistent poor sleepers were more likely to be woman (odds ratio [OR] = 1.98, 95% confidence interval [CI] 1.01–3.90), use painkillers prior to treatment (OR = 2.52, 95% CI 1.33–4.77), and have more pre-treatment anxiety symptoms (OR = 1.26, 95% CI 1.15–1.38). Conclusion: Unfavorable sleep quality trajectories are prevalent among HNC patients from pre-treatment to 6-month after treatment. A periodic sleep evaluation starting shortly after HNC diagnosis is necessary to identify persistent sleep problems, especially among high-risk group

    Poor sleep quality among newly diagnosed head and neck cancer patients:prevalence and associated factors

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    BACKGROUND: Head and neck cancer (HNC) patients often suffer from distress attributed to their cancer diagnosis which may disturb their sleep. However, there is lack of research about poor sleep quality among newly diagnosed HNC patients. Therefore, our aim was to investigate the prevalence and the associated factors of poor sleep quality among HNC patients before starting treatment. MATERIALS AND METHODS: A cross-sectional study was conducted using the baseline data from NET-QUBIC study, an ongoing multi-center cohort of HNC patients in the Netherlands. Poor sleep quality was defined as a Pittsburgh Sleep Quality Index (PSQI) total score of > 5. Risk factors examined were sociodemographic factors (age, sex, education level, living situation), clinical characteristics (HNC subsite, tumor stage, comorbidity, performance status), lifestyle factors, coping styles, and HNC symptoms. RESULTS: Among 560 HNC patients, 246 (44%) had poor sleep quality before start of treatment. Several factors were found to be significantly associated with poor sleep: younger age (odds ratio [OR] for each additional year 0.98, 95% CI 0.96-1.00), being female (OR 2.6, 95% CI 1.7-4.1), higher passive coping style (OR 1.18, 95% CI 1.09-1.28), more oral pain (OR 1.10, 95% CI 1.01-1.19), and less sexual interest and enjoyment (OR 1.13, 95% CI 1.06-1.20). CONCLUSION: Poor sleep quality is highly prevalent among HNC patients before start of treatment. Early evaluation and tailored intervention to improve sleep quality are necessary to prepare these patients for HNC treatment and its consequences
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