When an asynchronous Web API is used, the rules become more complicated. A built-in API that you can test this with is setTimeout, which sets a timer and performs an action after a specified amount of time. setTimeout needs to be asynchronous, otherwise the entire browser would remain frozen during the waiting, which would result in a poor user experience.
The task is to get the third function to always delay execution until after the asynchronous action in the second function has completed. This is where callbacks come in. Instead of executing first, second, and third at the top-level of execution, you will pass the third function as an argument to second. The second function will execute the callback after the asynchronous action has completed.
This section of the tutorial showed that promises incorporate a lot of improvements for dealing with asynchronous code. But, while using then to handle asynchronous actions is easier to follow than the pyramid of callbacks, some developers still prefer a synchronous format of writing asynchronous code. To address this need, ECMAScript 2016 (ES7) introduced async functions and the await keyword to make working with promises easier.
When an UPDATE or DELETE operation affects a key value in the parent table that has matching rows in the child table, the result depends on the referential action specified by ON UPDATE and ON DELETE subclauses of the FOREIGN KEY clause. Referential actions include:
A foreign key constraint on a stored generated column cannot use CASCADE, SET NULL, or SET DEFAULT as ON UPDATE referential actions, nor can it use SET NULL or SET DEFAULT as ON DELETE referential actions.
In MySQL 5.7.13 and earlier, InnoDB does not permit defining a foreign key constraint with a cascading referential action on the base column of an indexed virtual generated column. This restriction is lifted in MySQL 5.7.14.
In MySQL 5.7.13 and earlier, InnoDB does not permit defining cascading referential actions on non-virtual foreign key columns that are explicitly included in a virtual index. This restriction is lifted in MySQL 5.7.14.
Volume 141. 2021. Systema Dipterorum Nomenclatural Notes I. Evenhuis, N.L. & Pape, T. (editors) 22 pp. [ pdf ] [published online 12 December 2021]- Editorial. Evenhuis, N.L. & Pape, T. (editors). P. 1 [ pdf ] [published online 1 November 2021]- A new name for Scrobicula Matile, 1970 (Diptera: Keroplatidae). Evenhuis, N.L. Pp. 3-4 [ pdf ] [published online 1 November 2021]- Nomenclatural and taxonomic notes on Dolichopodidae genus-group names (Insecta: Diptera). Evenhuis, N.L. & Bickel, D.J. Pp. 5-11. [ pdf ] [published online 3 November 2021]- First Reviser actions for multiple original spellings of species-group names in Tabanidae, Mydidae, Dolichopodidae, Syrphidae, and Phoridae (Diptera). Evenhuis, N.L. pp. 13-16. pdf ][published online 23 November 2021]- Type species designations for five Hermann Loew genus-group names (Diptera: Asilidae, Heleomyzidae, Platystomatidae, Tephritidae). Evenhuis, N.L. Pp. 17-22. [ pdf ] [published online 12 December 2021]
The present review of Alzheimer's disease (AD) rating scales aims to outline the need for a new rating scale to be used in routine clinical practice for long-term medical care of AD patients. An ideal scale would be: 1) practical, easy and quick to administer for an experienced clinician; 2) validated for AD; 3) multi-domain: covering the AD-relevant areas of cognition, activities of daily living, behavior, communication/social interaction, and quality of life; 4) applicable to all AD severity stages; 5) able to monitor disease progression; and 6) sensitive to measure therapy effects.
In this paper, we provide a brief overview on AD scales developed for assessment of cognition, daily function, global impression, behavior, quality of life as well as communication and social interaction, with a focus on their applicability in daily medical practice for monitoring disease progression and therapy effects. The review does not pretend to have included all scales available and used in AD clinical practice so far. It rather summarizes individual scales for the various AD symptom domains and points to the need for a new multi-domain AD scale to enable disease assessment over time in daily medical practice.
To discover available AD scales covering the requirements listed in Table 1, we performed a systematic literature search, employing the National Library of Medicines' MEDLINE database. For this purpose, an appropriate search algorithm was established: i) to ensure the inclusion of records about tools used in the assessment of AD (keywords: Alzheimer ('s disease), scale, assessment, rating/rater, questionnaire); ii) to avoid the inclusion of records about measures only for AD diagnosis and staging (keywords: efficacy, outcome, disease progression); iii) to include records on aspects considered neglected in many AD scales (keywords: quality of life, communication, social interaction/activities). Only documents in English, French, German, Italian, and Spanish were considered. Measures specialized on specific topics (for example, assessment of visuospatial functioning, verbal learning) or not developed for AD, dementia, or geriatric patients were omitted. Computerized instruments were not considered due to the technical demands often deemed incompatible with daily practice use. Caregiver burden tools were also excluded since only scales for assessment of AD symptoms were of interest for this literature review.
Our systematic literature search revealed a total of 1,902 articles published from July 1981 to September 2008. By screening the results, special attention was paid to identification of scales containing items of several AD symptom domains, excluding instruments mainly used for AD diagnosis and staging or screening tests. Reviews, editorials, meta-analyses, or studies published in English, French, German, Italian, and Spanish languages were considered. Most of the selected articles referred to validated and AD-specific tools developed over the last three decades to assess the regulatory relevant AD-symptom complexes: cognition, activities of daily living (ADL), and global changes. The rest of the articles revealed instruments for assessment of behavior, patient's quality of life, and communication and social interaction. Out of all selected articles, 68 relevant AD scales were identified. An overview of the scales grouped by AD symptom domains is provided in Table 2.
To enable the assessment of cognition in later AD stages, the Severe Impairment Battery (SIB) was developed [6, 18]. The SIB, rather than rating erroneous performance, relies on the appraisal of preserved abilities in nine cognitive domains: social interaction, memory, orientation, language, attention, praxis, visuospatial abilities, constructional abilities and orientation to name. A maximum of 30 minutes is required for administration. A short SIB version  and a version based on the SIB-language domain, SIB-L , have also been developed. Another brief, reliable and valid measure of cognitive function in severely demented AD patients is the Severe Cognitive Impairment Rating Scale . For staging the severity of cognitive deficits and assessing the benefits of AD therapy, the Syndrom-Kurztest  has extensively been used in earlier clinical trials. It is well accepted by patients, hospital clinicians, and general practitioners due to its brevity and simplicity.
In the second half of the 1990 s, following a general medical trend of moving away from mainly symptom treatment towards patient-centered medical care, the development of scales for assessment of quality of life (QoL) became a new challenge. Most dementia QoL-scales refer to Lawton's model of QoL in dementia . According to this model, QoL is the result of a dynamic interaction between four patient-relevant dimensions: psychological well being, perceived quality of life, behavior competence, and environment . QoL scales contain aspects not considered in most conventional scales, such as interpersonal relationships, self-esteem, living environment, being useful, giving meaning to life, or financial situation. In general, QoL instruments are specific to the severity stage of AD and differ with regard to the domains covered. Most QoL scales are short and easy to administer. However, there has been substantial debate whether patients with AD, especially in more advanced stages, can reliably report on their QoL and whether caregiver reports are an appropriate alternative . Furthermore, the individual designation of QoL is rather flexible and inherently differing among people, which makes the common understanding of what is important for the QoL of a person with dementia a challenge for researchers and clinicians. To rate the extent to which treatment goals individually defined by the patient, caregiver or physicians are achieved, the method of goal attainment scaling was developed and applied to both geriatric and dementia populations . 2b1af7f3a8