1,752 research outputs found
Proceedings of IIASA Planning Conference on Optimization and Control of Complex Dynamic Systems, October 3-5,1973
PROBLEMS OF THE EXPRESSION OF CONDITIONAL RELATIONSHIPS IN THE UZBEK LANGUAGE
The article is aimed at investigating the problems of the expression of conditionals in the Uzbek language. Particularly, in the article a special emphasis is placed on the analysis of peculiarities of formal expressions of conditionals in the Uzbek language. The objectives of the research are formed by defining the notion of condition in Uzbek, studying the forms of expression of the conditionals, analyzing the syntactic structure of the conditional constructions, identifying the levels of language in which conditionals are expressed, analyzing the functions of conjunctions connecting the clauses of conditional sentences and identifying the stylistic features of conditional conjunctions. Linguistic description, generalization of prior ideas and theories in the field and componential analysis methods are used. The results of the study have shown that the conditionals are expressed by the synthetic and analytic forms, the synthetic forms (conditionals formed by affixes) refer to the conditional forms constructed by adding the conditional affix “-sа” to the stem of the verb, the analytic forms (the combination with two or more components) include the form of“-sа”+ to’liqsiz fe’l (an auxiliary verb (edi, ekan, emish), the combination of a part of speech which is not a verb+bo’l (to be)+sa, lexical units as desa, bo’lsa, yo’qsa and proverbs. The conditionals are mainly expressed at the grammatical and lexical levels of the language. In the grammatical layer, the conditionals are especially expressed through a syntactic unit which is a complex sentence and it is important to note the role of the conditional affix “-sa” in expressing a conditionat the morphological level. In the lexical layer, some lexical units and proverbs can be regarded as means of expressing conditionality. Also,conditional clauses are connected by various conjunctions (agar, basharti, mabodo, bordiyu, madomiki all referring to “if” in English) and these connectives possess different stylistic colorings and the main function of such conjunctions is not to express conditionality, but to emphasize and exaggerate a conditional meaning. So, the structural peculiarities of conditionals in Uzbek are determined by their syntactic structure, their expression in different language levels and the conditional conjunctions
Competing risk events in antimalarial drug trials in uncomplicated Plasmodium falciparum malaria: a WorldWide Antimalarial Resistance Network individual participant data meta-analysis.
BACKGROUND: Therapeutic efficacy studies in uncomplicated Plasmodium falciparum malaria are confounded by new infections, which constitute competing risk events since they can potentially preclude/pre-empt the detection of subsequent recrudescence of persistent, sub-microscopic primary infections. METHODS: Antimalarial studies typically report the risk of recrudescence derived using the Kaplan-Meier (K-M) method, which considers new infections acquired during the follow-up period as censored. Cumulative Incidence Function (CIF) provides an alternative approach for handling new infections, which accounts for them as a competing risk event. The complement of the estimate derived using the K-M method (1 minus K-M), and the CIF were used to derive the risk of recrudescence at the end of the follow-up period using data from studies collated in the WorldWide Antimalarial Resistance Network data repository. Absolute differences in the failure estimates derived using these two methods were quantified. In comparative studies, the equality of two K-M curves was assessed using the log-rank test, and the equality of CIFs using Gray's k-sample test (both at 5% level of significance). Two different regression modelling strategies for recrudescence were considered: cause-specific Cox model and Fine and Gray's sub-distributional hazard model. RESULTS: Data were available from 92 studies (233 treatment arms, 31,379 patients) conducted between 1996 and 2014. At the end of follow-up, the median absolute overestimation in the estimated risk of cumulative recrudescence by using 1 minus K-M approach was 0.04% (interquartile range (IQR): 0.00-0.27%, Range: 0.00-3.60%). The overestimation was correlated positively with the proportion of patients with recrudescence [Pearson's correlation coefficient (ρ): 0.38, 95% Confidence Interval (CI) 0.30-0.46] or new infection [ρ: 0.43; 95% CI 0.35-0.54]. In three study arms, the point estimates of failure were greater than 10% (the WHO threshold for withdrawing antimalarials) when the K-M method was used, but remained below 10% when using the CIF approach, but the 95% confidence interval included this threshold. CONCLUSIONS: The 1 minus K-M method resulted in a marginal overestimation of recrudescence that became increasingly pronounced as antimalarial efficacy declined, particularly when the observed proportion of new infection was high. The CIF approach provides an alternative approach for derivation of failure estimates in antimalarial trials, particularly in high transmission settings
Self-interest bias in the COVID-19 pandemic: A cross-cultural comparison between the United States and China
In the global crisis of the COVID-19 pandemic, many countries attempt to enforce new social norms to prevent the further spread of the coronavirus. A key to the success of these measures is the individual adherence to norms that are collectively beneficial to contain the spread of the pandemic. However, individuals’ self-interest bias (i.e., the prevalent tendency to license own but not others’ self-serving acts or norm violations) can pose a challenge to the success of such measures. The current research examines COVID-19-related self-interest bias from a cross-cultural perspective. Two studies (N = 1,558) sampled from the United States and China consistently revealed that participants from the United States evaluated their own self-serving acts (exploiting test kits in Study 1; social gathering and sneezing without covering the mouth in public in Study 2) as more acceptable than identical deeds of others, while such self-interest bias did not emerge among Chinese participants. Cultural underpinnings of independent versus interdependent self-construal may influence the extent to which individuals apply self-interest bias to justifications of their own self-serving behaviors during the pandemic
Temporal distribution of Plasmodium falciparum recrudescence following artemisinin-based combination therapy: an individual participant data meta-analysis.
BACKGROUND: The duration of trial follow-up affects the ability to detect recrudescent infections following anti-malarial treatment. The aim of this study was to explore the proportions of recrudescent parasitaemia as ascribed by genotyping captured at various follow-up time-points in treatment efficacy trials for uncomplicated Plasmodium falciparum malaria. METHODS: Individual patient data from 83 anti-malarial efficacy studies collated in the WorldWide Antimalarial Resistance Network (WWARN) repository with at least 28 days follow-up were available. The temporal and cumulative distributions of recrudescence were characterized using a Cox regression model with shared frailty on study-sites. Fractional polynomials were used to capture non-linear instantaneous hazard. The area under the density curve (AUC) of the constructed distribution was used to estimate the optimal follow-up period for capturing a P. falciparum malaria recrudescence. Simulation studies were conducted based on the constructed distributions to quantify the absolute overestimation in efficacy due to sub-optimal follow-up. RESULTS: Overall, 3703 recurrent infections were detected in 60 studies conducted in Africa (15,512 children aged 48 mg/kg total piperaquine (PIP) dose and 9% [95% CI 0-22%] in those treated with ≤ 48 mg/kg PIP dose. In absolute terms, the simulation study found that trials limited to 28 days follow-up following AL underestimated the risk of recrudescence by a median of 2.8 percentage points compared to day 63 estimates and those limited to 42 days following DP underestimated the risk of recrudescence by a median of 2.0 percentage points compared to day 42 estimates. The analysis was limited by few clinical trials following patients for longer than 42 days (9 out of 83 trials) and the imprecision of PCR genotyping which overcalls recrudescence in areas of higher transmission biasing the later distribution. CONCLUSIONS: Restricting follow-up of clinical efficacy trials to day 28 for AL and day 42 for DP will miss a proportion of late recrudescent treatment failures but will have a modest impact in derived efficacy. The results highlight that as genotyping methods improve consideration should be given for trials with longer duration of follow-up to detect early indications of emerging drug resistance
The New Dutch ICS 2003-2008 Research Program
Le nouveau programme de recherche 2003-2008 du centre hollandais ICS: Le Centre interuniversitaire de théorie et de méthodologie en sciences sociales (ICS) est une école doctorale et un centre de recherche fondé en 1989 qui comprend les universités de Groningen, Utrecht et Nijmegen. L'an dernier, en plus de son renouvellement par l'Académie royale hollandaise des arts et des sciences (KNAW), d'importants changements ont eu lieu ; ils sont décrits en détails dans son récent Annual Report d'où est tiré cet article. Le programme de recherche de l'ICS comprend maintenant une branche Réseaux sociaux, solidarité et inégalités qui est présentée ici avec les quatre autres branches de recherche et la liste complète des doctorants ICS (le titre de leur thèse).The Interuniversity Center for Social Science Theory and Methodology (ICS), which is a graduate school and research center, was founded in 1989 and includes the University of Groningen, Utrecht University and the University of Nijmegen. Last year, along with re-accreditation by the Royal Dutch Academy of Arts and Sciences (KNAW), a number of important changes took place at the ICS which are developed in detail in its recently-published Annual Report from which this article was developed. The ICS research program now includes a Social Networks, Solidarity and Inequality branch which is presented here along with the four other branches and the full list of ICS Ph.D students and their thesis topics
Rehabilitation definition for research purposes. A global stakeholders’ initiative by Cochrane Rehabilitation
Negrini S, Selb M, Kiekens C, et al. Rehabilitation definition for research purposes. A global stakeholders initiative by Cochrane Rehabilitation. European Journal of Physical and Rehabilitation Medicine . 2022.Since its foundation, Cochrane Rehabilitation has faced challenges with rehabilitation definitions because existing definitions did not indicate what rehabilitation includes and what it excludes. We aimed to develop a comprehensive and shared rehabilitation definition for research purposes to: 1) support the conduct of primary studies and systematic reviews, and 2) identify relevant systematic reviews for knowledge translation purposes. We performed a multimodal study including seven preliminary research and discussion papers, four Consensus Meetings and three Delphi rounds with 80 rehabilitation stakeholders. The Delphi Study aimed to obtain agreement, refine and complete the items composing the definition and meanings of rehabilitation. These stakeholders covered 5 continents, representing 11 global and continental rehabilitation organizations, 11 scientific journals, 4 Cochrane Networks and 3 Cochrane Groups, and included invited experts, and representatives of low middle-income countries (LMICs) and consumers. We had a 70% to 82.5% response rate to the three Delphi rounds, during which participants responded to all items (100%) and provided relevant comments (range 5.5-50% per item). This participation led to several refinements to the rehabilitation definition through three preliminary versions, and the final items reached an agreement between 88.9% and 100%. We structured the definition using the PICO (Population, Intervention, Comparison, Outcome) framework. We concluded that "In a health care context," rehabilitation is defined as a "multimodal, person-centered, collaborative process" (Intervention-general), including interventions targeting a person's "capacity (by addressing body structures, functions, and activities/participation) and/or contextual factors related to performance" (Intervention-specific) with the goal of "optimizing" the "functioning" (Outcome) of "persons with health conditions currently experiencing disability or likely to experience disability, or persons with disability" (Population). Rehabilitation requires that all the items of the definition are satisfied. We defined a "rehabilitation intervention" as "any intervention provided within the rehabilitation process." We developed a rehabilitation definition for research purposes achieving a broad agreement with global stakeholders. This definition provides explicit criteria to define rehabilitation. Using the proposed definition will improve rehabilitation research by standardizing the description of interventions. Our definition may require revision in the future, as further research enhances understanding and communication of the essence and complexity of rehabilitation
Harmonization and standardization of nucleus pulposus cell extraction and culture methods
BACKGROUND: In vitro studies using nucleus pulposus (NP) cells are commonly used to investigate disc cell biology and pathogenesis, or to aid in the development of new therapies. However, lab-to-lab variability jeopardizes the much-needed progress in the field. Here, an international group of spine scientists collaborated to standardize extraction and expansion techniques for NP cells to reduce variability, improve comparability between labs and improve utilization of funding and resources. METHODS: The most commonly applied methods for NP cell extraction, expansion, and re-differentiation were identified using a questionnaire to research groups worldwide. NP cell extraction methods from rat, rabbit, pig, dog, cow, and human NP tissue were experimentally assessed. Expansion and re-differentiation media and techniques were also investigated. RESULTS: Recommended protocols are provided for extraction, expansion, and re-differentiation of NP cells from common species utilized for NP cell culture. CONCLUSIONS: This international, multilab and multispecies study identified cell extraction methods for greater cell yield and fewer gene expression changes by applying species-specific pronase usage, 60-100 U/ml collagenase for shorter durations. Recommendations for NP cell expansion, passage number, and many factors driving successful cell culture in different species are also addressed to support harmonization, rigor, and cross-lab comparisons on NP cells worldwide
Competing risk events in antimalarial drug trials in uncomplicated Plasmodium falciparum malaria: a WorldWide Antimalarial Resistance Network individual participant data meta-analysis
Background: Therapeutic efcacy studies in uncomplicated Plasmodium falciparum malaria are confounded by new
infections, which constitute competing risk events since they can potentially preclude/pre-empt the detection of
subsequent recrudescence of persistent, sub-microscopic primary infections.
Methods: Antimalarial studies typically report the risk of recrudescence derived using the Kaplan–Meier (K–M)
method, which considers new infections acquired during the follow-up period as censored. Cumulative Incidence
Function (CIF) provides an alternative approach for handling new infections, which accounts for them as a competing
risk event. The complement of the estimate derived using the K–M method (1 minus K–M), and the CIF were used to
derive the risk of recrudescence at the end of the follow-up period using data from studies collated in the WorldWide
Antimalarial Resistance Network data repository. Absolute diferences in the failure estimates derived using these two
methods were quantifed. In comparative studies, the equality of two K–M curves was assessed using the log-rank
test, and the equality of CIFs using Gray’s k-sample test (both at 5% level of signifcance). Two diferent regression
modelling strategies for recrudescence were considered: cause-specifc Cox model and Fine and Gray’s sub-distributional hazard model.
Results: Data were available from 92 studies (233 treatment arms, 31,379 patients) conducted between 1996 and
2014. At the end of follow-up, the median absolute overestimation in the estimated risk of cumulative recrudescence
by using 1 minus K–M approach was 0.04% (interquartile range (IQR): 0.00–0.27%, Range: 0.00–3.60%). The overestimation was correlated positively with the proportion of patients with recrudescence [Pearson’s correlation coefcient
(ρ): 0.38, 95% Confdence Interval (CI) 0.30–0.46] or new infection [ρ: 0.43; 95% CI 0.35–0.54]. In three study arms, the
point estimates of failure were greater than 10% (the WHO threshold for withdrawing antimalarials) when the K–M
method was used, but remained below 10% when using the CIF approach, but the 95% confdence interval included
this threshold.
Conclusions: The 1 minus K–M method resulted in a marginal overestimation of recrudescence that became increasingly pronounced as antimalarial efcacy declined, particularly when the observed proportion of new infection was high. The CIF approach provides an alternative approach for derivation of failure estimates in antimalarial trials,
particularly in high transmission settings
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