51,595 research outputs found
Psychometric Properties and Factor Structure of the Colombian Version of the Short Health Anxiety Inventory (SHAI)
No full textAim: The SHAI is a well-established, brief, valid, and reliable self-report measure of health anxiety (HA) widely used worldwide in medical and non-medical contexts. Subjects and methods: The psychometric properties, internal consistency, and fit indices of the scale’s structure were examined in 867 Colombian adolescents (458 women and 409 men; M = 15.97; SD = 1.37). Results: The high reliability for SHAI was confirmed. Three models were tested, and the best-fitting model was the original two-factor structure (Fear of Illness and Negative Consequences of an Illness). Fit indices supported the two-factor model with a Comparative Fit Index (CFI) = 0.961 and Root Mean Square Error of Approximation (RMSEA) = 0.047 (90 % CI: .041–0.052). The total reliability of the scale was α = 0.82, which can be considered significant and high, with reports of α = 0.80 and α = 0.68 for the factors of Fear of Disease and Negative Consequences of Disease, respectively. While reliability was excellent, the model’s fit was also adequate and consistent with the original structure. Conclusion: The Colombian version of the SHAI is a valid and reliable tool for assessing health anxiety in clinical practice and the research field
The Returning Secretary
No full textIn the online random-arrival model, an algorithm receives a sequence of requests that arrive in a random order. The algorithm is expected to make an irrevocable decision with regard to each request based only on the observed history. We consider the following natural extension of this model: each request arrives k times, and the arrival order is a random permutation of the kn arrivals; the algorithm is expected to make a decision regarding each request only upon its last arrival. We focus primarily on the case when k=2, which can also be interpreted as each request arriving at, and departing from the system, at a random time.
We examine the secretary problem: the problem of selecting the best secretary when the secretaries are presented online according to a random permutation. We show that when each secretary arrives twice, we can achieve a competitive ratio of 0.767974... (compared to 1/e in the classical secretary problem), and that it is optimal. We also show that without any knowledge about the number of secretaries or their arrival times, we can still hire the best secretary with probability at least 2/3, in contrast to the impossibility of achieving a constant success probability in the classical setting.
We extend our results to the matroid secretary problem, introduced by Babaioff et al. [3], and show a simple algorithm that achieves a 2-approximation to the maximal weighted basis in the new model (for k=2). We show that this approximation factor can be improved in special cases of the matroid secretary problem; in particular, we give a 16/9-competitive algorithm for the returning edge-weighted bipartite matching problem
A Rövidített Egészségszorongás-kérdőív (SHAI) magyar verziójának kérdőíves validálása és pszichometriai értékelése = Validation and psychometric evaluation of the Hungarian version of the Short Health Anxiety Inventory (SHAI)
No full textElméleti háttér és célkitűzés: Jelen kutatás célja a Rövidített Egészségszorongás-kérdőív (Short Health Anxiety Inventory — SHAI; Salkovskis, Rimes, Warwick, & Clark, 2002) magyar verziójának elkészítése, pszichometriai értékelése és kérdőíves validálása volt.
Módszerek: A vizsgálatban 441 alsóéves egyetemista (37% férfi; átlagéletkor: 20,5±1,33 év) vett részt, összesen 5 kérdőív kitöltésével (SHAI; Szomatoszenzoros Amplifikáció — SSAS; Vonásszorongás — STAI-T; Szubjektív Testi Tünetek — PHQ-15; WHO Jól-lét — WBI-5).
Eredmények: A megerősítő faktorelemzés mind a két-, mind a háromfaktoros verzió esetében jó illeszkedési mutatókat eredményezett, ezért az irodalomban inkább elfogadott két alskálás (Beteggé válás észlelt valószínűsége; Betegség észlelt következménye) megoldás használatát javasoljuk. A kérdőív magyar verziója jó belső konzisztenciával (Cronbach-alfa = 0,83) bírt, a STAI-T, az SSAS és a PHQ-15 skálákkal közepes erősségű (Pearson-r: 0,33—0,44; p<0,001) korrelációt mutatott, míg a WBI-5 esetében az együttjárás gyengébbnek és negatív irányúnak mutatkozott (—0,26; p<0,001).
Következtetések: Az eredmények alapján a kérdőív pszichometriai szempontból megfelelőnek tűnik, ugyanakkor a végső értékeléshez a vizsgálatot érdemes volna más mintákon is megismételni.
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Aim: The study aimed at the preparation, psychometric evaluation and questionnaire-based validation of the Hungarian version of the Short Health Anxiety Inventory (SHAI; Salkovskis et al. 2002).
Methods: 441 undergraduate students (37% male; mean age: 20.5±1.33 yrs) completed five questionnaires (SHAI; Somatosensory Amplification — SSAS; Trait Anxiety — STAI-T; Subjective Somatic Symptoms — PHQ-15; Well-being — WHO-WB).
Results: The confirmatory factor analysis indicated equally good fit between the empirical data and the two- and three-factor-models described in the literature. In the light of the international findings, the use of two subscales (Illness Likelihood and Illness Severity) seems to be preferable. The Hungarian version of the questionnaire has shown good internal consistency (Cronbach’s alfa = 0.83) and medium level correlations (Pearson’s coefficients between 0.33 and 0.44; p<0,001) with the STAI-T, SSAS and PHQ-15 scales. The association with the WBI-5 was weaker and negative (r = —0.26; p<0.001).
Conclusion: According to the results, the Hungarian version of the SHAI has good psychometric properties. To come to a final conclusion, replication of the study in different samples would be necessary
Vascular endothelial growth factor restores delayed tumor progression in tumors depleted of macrophages
No full textGenetic depletion of macrophages in Polyoma Middle T oncoprotein (PyMT)-induced mammary tumors in mice delayed the angiogenic switch and the progression to malignancy. To determine whether vascular endothelial growth factor A (VEGF-A) produced by tumor-associated macrophages regulated the onset of the angiogenic switch, a genetic approach was used to restore expression of VEGF-A into tumors at the benign stages. This stimulated formation of a high-density vessel network and in macrophage-depleted mice, was followed by accelerated tumor progression. The expression of VEGF-A led to a massive infiltration into the tumor of leukocytes that were mostly macrophages. This study suggests that macrophage-produced VEGF regulates malignant progression through stimulating tumor angiogenesis, leukocytic infiltration and tumor cell invasion
Comparative Advantages, Transaction Costs and Factor Content in Agricultural Trade: Empirical Evidence from the CEE
No full textThe present study examines factor content in the CEE transition country agricultural trade. However, deviating from the traditional approach, we do not test the HOV prediction. Instead, we examine the theoretical predictions that relate the factor content of international trade to cross-country differences in technology and endowments. Our empirical findings suggest that factor content between agricultural exports and imports is rather similar in CEE. In order to explain the general lack of the CEE agricultural specialisation and the observed paradox, we attempt to identify the role of transaction costs and market imperfections in determining factor content in agricultural production and trade. We find that technological differences and factor endowment are only weak determinants of country specialisation. Transaction costs and market imperfections distort farm specialisation and organisation in CEE, and hence factor content in traded agricultural goods.Comparative Advantage, Transaction Cost, Factor Content, Trade, International Relations/Trade,
Skin friction factor and mean velocity profile measured in high-reynolds-number turbulent pipe flow
No full textA friction factor in a fully developed pipe flow is measured very accurately over wide range Reynolds number from 103 to 107 at the high Reynolds number facility in AIST,NMIJ. Also a velocity profile is measured by using a LDV up to 106. From the comparison between a velocity profile and the friction factor, we found that a log-law profile is well observed and Kármán constant is estimated to be 0.385. Based on the measurements, we present a new functional form of the friction factor which is consistent with mean velocity profile
Biodegradation of labile dissolved organic carbon under losing and gaining streamflow conditions simulated in a laboratory flume
No full textCarbon in surface waters is widely recognized as a key element that influences nutrient cycling, metal availability and water quality. Its degradation in streams occurs primarily by benthic microbial communities that colonize the underlying sediment, which is commonly termed the hyporheic zone (HZ). The biodegradation of a labile dissolved organic carbon (DOCL), exemplified by sodium benzoate, was studied in a novel laboratory flume system under a combination of different overlying water velocities, losing or gaining fluxes, and biofilm distribution ("surficial" or "homogeneous distribution"). The overall objective of this study was to evaluate the effect of different flow conditions on DOCL biodegradation in the HZ. The results showed that overlying velocity was the dominant factor affecting DOCL biodegradation, regardless of biofilm distribution. Gaining flow conditions also induced a slight increase in the biodegradation rates as compared to losing or neutral flow conditions, due to additional oxygen input from the upwelling water. The aerobic reactive zone under all flow conditions was limited to the upper section of the benthic biofilm (several millimeters), where the surficial biofilm showed the highest activity. Our results and interpretation of DOCLbiodegradation processes in the hyporheic zone are expected to improve the understanding and modeling of DOC transport in stream
Relation of skewness factor and convection velocity in turbulent boundary layer
No full textThe paper is devoted to prove the relation between skewness factor and convection velocity in turbulent boundary layer. It appears that skewness factor can be used as an indicator of convection velocity of coherent structures, which is not always equal to the average flow velocity. The analysis has been performed based upon velocity profiles measured with hot-wire technique in turbulent boundary layer with pressure gradient corresponding to turbomachinery conditions. The results show that the cross product term of skewness factor decomposed by spectral filtering, which is also alternative measure of amplitude modulation, describes the convection velocity in zero pressure gradient turbulent boundary layer
Open access self-archiving: An author study
No full textThis, our second author international, cross-disciplinary study on open access had 1296 respondents. Its focus was on self-archiving. Almost half (49%) of the respondent population have self-archived at least one article during the last three years. Use of institutional repositories for this purpose has doubled and usage has increased by almost 60% for subject-based repositories. Self-archiving activity is greatest amongst those who publish the largest number of papers. There is still a substantial proportion of authors unaware of the possibility of providing open access to their work by self-archiving. Of the authors who have not yet self-archived any articles, 71% remain unaware of the option. With 49% of the author population having self-archived in some way, this means that 36% of the total author population (71% of the remaining 51%), has not yet been appraised of this way of providing open access. Authors have frequently expressed reluctance to self-archive because of the perceived time required and possible technical difficulties in carrying out this activity, yet findings here show that only 20% of authors found some degree of difficulty with the first act of depositing an article in a repository, and that this dropped to 9% for subsequent deposits. Another author worry is about infringing agreed copyright agreements with publishers, yet only 10% of authors currently know of the SHERPA/RoMEO list of publisher permissions policies with respect to self-archiving, where clear guidance as to what a publisher permits is provided. Where it is not known if permission is required, however, authors are not seeking it and are self-archiving without it. Communicating their results to peers remains the primary reason for scholars publishing their work; in other words,
researchers publish to have an impact on their field. The vast majority of authors (81%) would willingly comply with a mandate from their employer or research funder to deposit copies of their articles in an institutional or subject-based repository. A further 13% would comply reluctantly; 5% would not comply with such a mandate
HER2-Low Breast Cancer: Current Landscape and Future Prospects
No full textYelena Shirman, Shlomit Lubovsky, Ayelet Shai Division of Oncology, Rambam Health Care Campus, Haifa, IsraelCorrespondence: Ayelet Shai, Division of Oncology, Rambam Health Care Campus, HaAliya HaShniya St 8, PO Box 9602, Haifa, 3109601, Israel, Tel +972-47776400, Email [email protected]: More than 50% of breast cancers are currently defined as “Human epidermal growth factor receptor 2 (HER2) low breast cancer (BC)”, with HER2 immunohistochemistry (IHC) scores of +1 or +2 with a negative fluorescence in situ hybridization (FISH) test. In most studies that compared the clinical and biological characteristics of HER2-low BC with HER2-negative BC, HER2-low was not associated with unique clinical and molecular characteristics, and it seems that the importance of HER2 in these tumors is being a docking site for the antibody portion of antibody drug conjugates (ADCs). Current pathological methods may underestimate the proportion of BCs that express low levels of HER2 due to analytical limitations and tumor heterogeneity. In this review we summarize and contextualize the most recent literature on HER2-low breast cancers, including clinical and translational studies We also review the challenges of assessing low HER2 expression in BC and discuss the current and future therapeutic landscape for these tumors.Keywords: HER2-low, ERBB2 low, breast cancer, HER2 targeted therapy, trastuzumab, trastuzumab-deruxtecan, T-DX
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