3,284 research outputs found

    The role of shifting, updating, and inhibition in prospective memory performance in young and older adults.

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    Prospective memory performance shows a decline in late adulthood. The present article examines the role of 3 main executive function facets (i.e., shifting, updating, and inhibition) as possible developmental mechanisms associated with these age effects. One hundred seventy-five young and 110 older adults performed a battery of cognitive tests including measures of prospective memory, shifting, updating, inhibition, working memory, and speed. Age effects were confirmed in prospective memory and also obtained in shifting, updating, and inhibition. Yet, facets of executive control differently predicted prospective memory performance: While inhibition and shifting were strong predictors of prospective memory performance and also explained age differences in prospective memory, updating was not related to prospective memory performance across adulthood. Furthermore, considering executive function measures increased the amount of explained variance in prospective remembering and reduced the influence of speed. Working memory was not revealed to serve as a significant predictor of prospective memory performance in the present study. These findings clarify the role of different facets of controlled attention on age effects in prospective memory and bear important conceptual implications: Results suggest that some but not all facets of executive functioning are important developmental mechanisms of prospective memory across adulthood beyond working memory and speed. Specifically, inhibition and shifting appear to be essential aspects of cognitive control involved in age-related prospective memory performance

    Difference in attitudes toward Crew Resource Management based on nationality

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    The E-3A Airborne Early Warning and Control System aircraft operates with multinational crewmembers from 15 different nations on 12 different aircrew positions. Given this non-standard cultural environment, the authors explored the differences in the attitude toward Crew Resource Management (CRM), based on nationality, and how these differences could be used as a predictor for other nationalities attitudes. The potential benefit of this study may be, that CRM methods could be developed further to either work universally, independent to national or cultural backgrounds, or be adjusted for different cultural contexts in order to be even more effective. Primary data was gathered through a survey questionnaire issued to aircrew members of the North Atlantic Treaty Organization (NATO) E-3A Component. The survey focused on key attitudes in a CRM environment such as teamwork ability, criticism appreciation, and open mindedness; taken from standardized questions based on Hofstede and Minkov’s (2013) Values Survey Module (VSM). Analyzing the gathered values, revealed that in fact differences between various nations exist. Comparing the cultural dimensions calculated for the participating nations in this study did not allow for a correlation of attitude differences to certain index patterns. Significantstatistical differences could be detected in three of the five questions, indicating that national culture and the attitude toward CRM does correlate and hence needs to be addressed in CRM training. CRM is not perfect and is, as always reiterated, a constantly evolving construct. One part of it, in the now globalized and more and more interrelated world, is to deal with different baselines that each culture brings into this coherent model

    Explaining Age-Differences in Working Memory: The Role of Updating, Inhibition, and Shifting

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    Working memory (WM) represents the capacity to store and process a limited amount of information. Better understanding developmental changes of WM forms a key topic in research on neuropsychology of aging. Previous studies reveal age-differences in WM and in executive functions (EFs). Although EFs are seen as essential mechanisms in WM, the specific relation between the two cognitive constructs so far remains unclear. The present study set out to investigate the unique roles of the three main facets of EFs (i.e., updating, inhibition, and shifting) in accounting for age-related variability in WM. Therefore, one-hundred seventy-five younger and 107 older adults performed a battery of cognitive tests including measures of WM, EFs, and processing speed. A set of statistical approaches including regression analyses and path models was used to examine the cognitive correlates that could explain individual and age-related variance in WM. Significant age-differences were found on WM and on EF measures. Regression analyses and path models showed that updating and inhibition but not shifting played a major role in explaining age-related variance in WM. In sum, findings suggest that updating and inhibition are most influential for age-differences in WM. They further show that age and processing speed do not significantly contribute to variability in WM performance beyond executive resource. The present findings have implications for conceptual and developmental theories of WM and may further offer an initial empirical basis for developing possible trainings to improve older adults’ WM performance by strengthening the efficiency of updating and inhibitory processes

    Per oral substitution with 300000 IU vitamin D (Cholecalciferol) reduces bone turnover markers in HIV-infected patients

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    BACKGROUND: Osteoporosis and bone fractures seem to be higher in HIV-infected Patients compared to the general populations. Moreover, bone turnover markers are increased in patients on antiretroviral therapy and vitamin D deficiency is prevalent in HIV-infected patients. However, the influence of per oral cholecalciferol on bone metabolism in HIV infected patients is not well understood. METHODS: We measured the bone turnover markers in 96 HIV-infected patients: Bone specific alkaline phosphatase (BSAP), Pyridinoline (PYR), Desoxypyridinoline (DPD) and 25-OH vitamin D. If 25-OH vitamin D was below 75 nnol/L (87/96 patients), 300000 IU cholecalciferol was given per os. 25OH-vitamin D and bone turn over markers were determinded 3 month later. 25 OH-vitamin D was corrected for circannual rythm [Formula: see text] , whereas bone turnover markers were not corrected. The paired students t-Test was used to compare the two periods. No calcium supplementation or biphosphonate therapy was given. RESULTS: Corrected 25OH-vitamin D levels increased significantly after supplementation (42.7 ± 26.61 vs. 52.85 ± 21.8 nmol/L, p < 0.001). After supplementation, bone turnover markers were significantly lower. The values decreased for BSAP from 21.31 ± 14.32 to 17.53 ± 8.17 μg/L (p < 0.001), PYR from 74.57 ± 36.83 to 54.82 ± 21.43 nmol/mmol creatinine (p < 0.001) and DPD from 15.17 ± 8.34 to 12.61 ± 5.02 nmol/mmol creatinine (p = 0.01). CONCLUSIONS: After per oral substitution with cholecalciferol, bone formation as well as bone resorption markers decreased significant. We postulate a protective effect on bone structure with cholecalciferol supplementation

    Radiation Dose and Fluoroscopy Time of Diagnostic Angiography in Patients with Spinal Dural Arteriovenous Fistula

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    PURPOSE Spinal dural arteriovenous fistulas (SDAVFs) represent the most common indication for a~spinal angiography. The diagnostic reference level (DRL) for this specific endovascular procedure is still to be determined. This single-center study provides detailed dosimetrics of diagnostic spinal angiography performed in patients with SDAVFs. METHODS Retrospective analysis of all diagnostic spinal angiographies between December 2011 and January 2021. Only patients with an SDAVF who had baseline magnetic resonance angiography (MRA), diagnostic digital subtraction angiography (DSA), treatment and follow-up at this institution were included. Dose area product (DAP, Gy cm2) and fluoroscopy time were compared between preoperative and postoperative angiographies, according to SDAVF locations (common versus uncommon), MRA results at baseline (positive versus negative) and DSA protocols (low-dose, mixed-dose, normal-dose). The 75th~percentile of the DAP distribution was used to define the local DRL. RESULTS A total of 62~spinal angiographies were performed in 25~patients with SDAVF. Preoperative angiographies (30/62, 48%) yielded a~significantly higher DAP and longer fluoroscopy time when compared to postoperative angiographies (32/62, 53%) (p 0.05). A~low-dose protocol yielded a~61% reduction of DAP. CONCLUSION The results of the present study suggest novel DRLs for spinal angiography in patients with SDAVF. Dedicated low-dose protocols enable radiation dose optimization in these procedures

    Radiation Dose and Fluoroscopy Time of Endovascular Treatment in Patients with Intracranial Lateral Dural Arteriovenous Fistulae

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    Purpose. Intracranial lateral dural arteriovenous fistula (LDAVF) represents a specific subtype of cerebrovascular fistulae, harboring a potentially life-threatening risk of brain hemorrhage. Fluoroscopically guided endovascular embolization is the therapeutic gold standard. We provide detailed dosimetry data to suggest novel diagnostic reference levels (DRL). Methods. Retrospective single-center study of LDAVFs treated between January 2014 and December 2019. Regarding dosimetry, the dose area product (DAP) and fluoroscopy time were analyzed for the following variables: Cognard scale grade, endovascular technique, angiographic outcome, and digital subtraction angiography (DSA) protocol. Results. A total of 70 patients (19 female, median age 65 years) were included. Total median values for DAP and fluoroscopy time were 325 Gy cm2 (25%/75% percentile: 245/414 Gy cm2) and 110 min (68/142min), respectively. Neither median DAP nor fluoroscopy time were significantly different when comparing low-grade with high-grade LDAVF (Cognard I + IIa versus IIb–V; p > 0.05, each). Transvenous coil embolization yielded the lowest dosimetry values, with significantly lower median values when compared to a combined transarterial/transvenous technique (DAP 290 Gy cm2 versus 388 Gy cm2, p = 0.031; fluoroscopy time 85 min versus 170 min, p = 0.016). A significant positive correlation was found between number of arterial feeders treated by liquid embolization and both DAP (rs = 0.367; p = 0.010) and fluoroscopy time (rs = 0.295; p = 0.040). Complete LDAVF occlusion was associated with transvenous coiling (p = 0.001). A low-dose DSA protocol yielded a 20% reduction of DAP (p = 0.021). Conclusion. This LDAVF study suggests several local DRLs which varied substantially dependent on the endovascular technique and DSA protocol

    Radiation dose and image quality of high-pitch emergency abdominal CT in obese patients using third-generation dual-source CT (DSCT)

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    In this third-generation dual-source CT (DSCT) study, we retrospectively investigated radiation dose and image quality of portal-venous high-pitch emergency CT in 60 patients (28 female, mean age 56 years) with a body mass index (BMI) (3) 30 kg/m(2). Patients were dichotomized in groups A (median BMI 31.5 kg/m(2);n = 33) and B (36.8 kg/m(2);n = 27). Volumetric CT dose index (CTDIvol), size-specific dose estimate (SSDE), dose length product (DLP) and effective dose (ED) were assessed. Contrast-to-noise ratio (CNR) and dose-independent figure-of-merit (FOM) CNR were calculated. Subjective image quality was assessed using a five-point scale. Mean values of CTDIvol, SSDE as well as normalized DLP and ED were 7.6 +/- 1.8 mGy, 8.0 +/- 1.8 mGy, 304 +/- 74 mGy * cm and 5.2 +/- 1.3 mSv for group A, and 12.6 +/- 3.7 mGy, 11.0 +/- 2.6 mGy, 521 +/- 157 mGy * cm and 8.9 +/- 2.7 mSv for group B (p 36.8 kg/m(2)

    Antiprädationsverhalten von Weißwangengänsen auf Kolguyev und Svalbard

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    Auch in den arktischen Brutgebieten sind Wildgänse und ihre Brut durch Fressfeinde wie den Eisfuchs (Alopex lagopus) oder die Eismöwe (Larus hyperboreus) gefährdet. In diesem Bericht wird am Beispiel von Weißwangengänsen (Branta leucopsis) das Verhalten der Vermeidung von Prädation auf Svalbard mit dem der auf Kolguyev brütenden Artgenossen untersucht. Die Unterschiede und Gemeinsamkeiten werden diskutiert.On the breeding grounds geese and their broods are threatened by predators like polar foxes (Alopex lagopus) or Glacous Gulls (Larus hyperboreus). In this review we compare antipredation behaviour of breeding and broad rearing Barnacle Geese (Branta leucopsis) on Svalbard and Kolguev. Similarities and differences are presented and discussed

    CT-Guided Drainage of Fluid Collections Following Liver Resection: Technical and Clinical Outcome of 143 Patients during a 14-Year Period

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    PURPOSE To retrospectively evaluate the technical and clinical outcome of patients with symptomatic postoperative fluid collections following liver resection treated with CT-guided drainage (CTD). METHODS 143 suitable patients were examined between 2004 and 2017. Technical success was defined as (a) sufficient drainage of the fluid collection and (b) the non-occurrence of peri-interventional complications requiring surgical treatment with minor or prolonged hospitalization. Clinical success was defined as (a) decreasing or normalization of specific blood parameters within 30 days after intervention and (b) no surgical revision in addition to intervention required. C-reactive protein (CRP), leukocytes and Total Serum Bilirubin (TSB) were assessed. Dose length product (DLP) for the intervention parts was determined. RESULTS Technical success was achieved in 99.5% of 189 performed interventions. Clinical success was reached in 74% for CRP, in 86.7% for Leukocytes and in 62.1% for TSB. The median of successful decrease was 6.0 days for CRP, 3.5 days for Leukocytes and 5.5 days for TSB. In 90.2%, no surgical revision was necessary. Total DLP was significantly lower in the second half of the observation period (median 536.0 mGy*cm between years 2011 and 2017 vs. median 745.5 mGy*cm between years 2004 and 2010). CONCLUSIONS Technical success rate of CTD was very high, and clinical success rate was fair to good. Reduction of the radiation dose reflects developments of CT technology and increased experience of the interventional radiologists
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