Abstract There is substantial evidence on the associations between cold ambient temperature and adverse health effects. Less is known about the role of prolonged episodes of cold weather denoted as cold spells. This study assessed relations between cold spells and adverse health effects globally, and quantified and elaborated the associations between cold spells and sudden cardiac death (SCD) in northern Finland. Based on random-effects models in the meta-analyses of evidence from 9 studies around the world, cold spells were associated with increased mortality rates from all or all non-accidental causes (RR 1.10; 95% CI: 1.04–1.17), cardiovascular diseases (RR 1.11; 95% CI: 1.03–1.19), and respiratory diseases (RR 1.21; 95% CI: 0.97–1.51). Suggestive evidence of other health effects was identified. Investigating 51-years of coordinate-specific weather data at the home coordinates of autopsy-verified cases of SCD, conditional logistic regression in a case-crossover setting produced an estimate for the association between cold spells and the risk of SCD (OR 1.33; 95% CI: 1.00–1.78). A greater number of cold days preceding death increased the risk of SCD approximately 19% per day (OR 1.19; 95% CI: 1.07–1.32). The association between season-specific cold spells and SCD was strongest during autumn and winter, and lowest during spring and summer. The association was stronger for ischemic (OR 1.55; 95% CI: 1.12–2.13) than for non-ischemic SCD (OR 0.68; 95% CI: 0.32–1.45) (Q-statistic 3.85, p 0.05), confirmed by the autopsy finding. Among cases suffering ischemic SCD, the association seemed stronger in those without a prior diagnosis of ischemic heart disease than in those diagnosed during lifetime. The association seemed stronger with severe coronary stenosis (OR 1.60; 95% CI: 1.11–2.30), and weaker with moderate stenosis (OR 0.97; 95% CI: 0.37–2.55). The use of aspirin, β-blockers, and nitrates seemed to decrease the risk of ischemic SCD during cold spells. In conclusion, cold spells increased the risk of ischemic SCD, and patients without appropriate diagnosis and medications for ischemic heart disease seemed most susceptible. The results indicate that coronary stenosis plays a central role in the cold-related pathogenesis of SCD. Timely diagnosis and treatment of ischemic heart disease might reduce weather-related SCDs in a community. / Tiivistelmä Kylmän lämpötilan ja terveyshaittojen välisistä yhteyksistä on vahva tutkimusnäyttö. Vähemmän tiedetään pitkittyneiden kylmäjaksojen ja terveyshaittojen välisistä yhteyksistä. Tutkimuksessa arvioitiin kylmäjaksojen ja terveyshaittojen välisiä yhteyksiä globaalisti, ja määritettiin kylmäjaksojen ja sydänperäisen äkkikuoleman (SÄK) välisiä yhteyksiä Pohjois-Suomessa. Yhdeksän eri puolella maailmaa toteutetun tutkimuksen tulosten meta-analyysissa satunnaisvaikutusten malli osoitti yhteyden kylmäjaksojen ja kaikkien tai luonnollisien syiden (RR 1.10; 95% CI: 1.04–1.17), sydän- ja verisuonisairauksien (RR 1.11; 95% CI: 1.03–1.19), ja hengityselimistön sairauksien (RR 1.21; 95% CI: 0.97–1.51) kuolleisuuden välillä. Viitteellistä näyttöä havaittiin muista terveyshaitoista. Tutkittaessa 51-vuoden koordinaattikohtaista säätä case-crossover-asetelmassa oikeuslääketieteellisesti vahvistettujen SÄK-tapausten kotiosoitteissa, ehdollisen logistisen regression mukaan SÄK:n riski oli yhteydessä kuolemaa edeltävään kylmäjaksoon (OR 1.33; 95% CI: 1.00–1.78). Lisääntyvä kylmien päivien lukumäärä ennen kuolemaa lisäsi riskiä keskimäärin 19% päivää kohden (OR 1.19; 95% CI: 1.07–1.32). Yhteys kausikohtaisten kylmäjaksojen ja SÄK:n välillä oli vahvin syksyllä ja talvella, ja heikoin keväällä ja kesällä. Yhteys oli vahvempi kylmäjaksojen ja iskeemisen SÄK:n (OR 1.55; 95% CI: 1.12–2.13) kuin kylmäjaksojen ja ei-iskeemisen SÄK:n (OR 0.68; 95% CI: 0.32–1.45) välillä (Q-statistic 3.85, p 0.05). Iskeemisen SÄK:n kokeneilla yhteys vaikutti vahvemmalta tapauksilla joilla ei ollut aiempaa iskeemisen sydänsairauden diagnoosia, kuin tapauksilla jotka oli diagnosoitu elinaikana. Yhteys vaikutti vahvemmalta vaikea-asteisesta sepelvaltimostenoosia sairastavilla (OR 1.60; 95% CI: 1.11–2.30), kuin lievempi-asteisessa stenoosissa (OR 0.97; 95% CI: 0.37–2.55). Aspiriini, β-salpaajat, ja nitraatit vaikuttivat vähentävän iskeemisen SÄK:n riskiä kylmäjakson aikana. Yhteenvetona, kylmäjaksot lisäsivät iskeemisen SÄK:n riskiä, ja potilaat vailla iskeemisen sydänsairauden diagnoosia ja lääkityksiä vaikuttivat olevan alttiimpia kylmäjaksojen haittavaikutuksille. Tulokset viittaavat sepelvaltimostenoosin keskeiseen rooliin kylmään liittyvän SÄK:n patogeneesissä. Varhainen iskeemisen sydänsairauden diagnoosi ja siihen liittyvä sydäntä suojaava lääkitys voisivat vähentää säähän liittyviä SÄK:a.

Este trabalho decorre de uma experiência etnográfica entre os Yuhupdeh, na região do alto rio Negro (ou Noroeste Amazônico). Essa região se caracteriza por possuir um sistema social que abarca três grandes famílias lingüísticas: Tukano Oriental, Aruak e Maku. Os Yuhupdeh (Maku) ocupam no sistema regional a posição de mais baixa hierarquia. A experiência buscou compreender aspectos do xamanismo, através de práticas relacionadas à doença e ao ritual. Para tanto, adotou dois focos etnográficos. O primeiro, dirigiu-se a situações em que os benzimentos de cura e de proteção são executados, e o segundo, às situações em que se realizou o dabucuri (festa de oferta de alimentos) com uso das flautas Jurupari (Tí). Os benzimentos de cura e proteção são fórmulas verbais onde o trabalho do benzedor se revelou como sendo o de composição de pessoas. O dabucuri com o uso das flautas Jurupari (Tí) é um ritual conduzido pelo benzedor, que pode incluir a iniciação masculina ou simplesmente a exibição das flautas. Nesse rituais, o trabalho do benzedor se apresenta como sendo o de composição de grupos. Em ambos os casos, os procedimentos são análogos. / The present work derives from an ethnographical experience among the Yuhupdeh, in the Upper Rio Negro region (Northwest Amazonia). The region is distinguished by a social system which includes three linguistic families: EasternTukanoan, Aruak and Maku. The Yuhupdeh (Maku) occupy the lowest hierarchical position in the regional system. The experience aims at understanding certain aspects of shamanism, through praxis related to disease and ritual, adopting two ethnographical focus. First, events of performed healing and protection benzimentos (spells) and second, events of performed dabucuri (give-food ritual) with Jurupari (Tí) flutes. Protection and healing benzimentos are verbal formulæ in which the benzedor appears as a composer of persons. The dabucuri with Jurupari flutes is a ritual conducted by the benzedor, which may include male initiation or simply be an exhibition of the flutes. In these rituals, the benzedor appears as a composer of groups. In both cases, his procedures are analogous.

Computers have been used effectively to provide support for people with a variety of special needs. One such group is adults with dyslexia. Dyslexia is commonly recognised as a learning disorder characterised by reading, writing and spelling difficulties. It inhibits recognition and processing of graphic symbols, particularly those pertaining to language. Computers are a useful aid for dyslexic adults, especially word processors and their associated spelling tools. However, there are still areas where improvements are needed. Creating an environment, which minimises visual discomfort associated with proof reading and making selections from lists would be of benefit. Furthermore providing the correct type and level of support for spelling, grammar and sentence construction may result in higher standards being achieved. A survey of 250 dyslexic adults established their requirements and enabled the development of a specialist word processing system and associated spelling support tools. The hypothesis, that using a language with enforced structure and rigid constraints has a positive affect for dyslexic adults, was also tested. A support tool, which provided a controlled environment, to assist with sentence construction for dyslexic adults was developed from this. Three environments were created using the word processing system: environment 1 used the basic system with no support, environment 2 provided spelling support suggested by the survey subjects and environment 3 used the sentence constructing tool providing support and control. Using these environments in controlled experiments indicated that although environment 2 achieved high academic standards, environment 3 produced written work to an even higher standard and at the same time, the subjects derived greater satisfaction in using it. This research proves that working in a controlled, rigid environment, where structure is enforced, substantially benefits dyslexic adults performing computer-based writing tasks.

Spell checkers are nowadays a common occurrence in most editors. A student writing an essay in school will often have the availability of a spell checker. However, the feedback from a spell checker seldom correlates with the feedback from a teacher. A reason for this being that the teacher has more aspects on which it evaluates a text. The teacher will, as opposed to the the spell checker, evaluate a text based on aspects such as genre adaptation, structure and word variation. This thesis evaluates how well those aspects translate to NLP (Natural Language Processing) and implements those who translate well into a rule based solution called Granska. / Grammatikgranskare finns numera tillgängligt i de flesta ordbehandlare. En student som skriver en uppsats har allt som oftast tillgång till en grammatikgranskare. Dock så skiljer det sig mycket mellan den återkoppling som studenten får från grammatikgranskaren respektive läraren. Detta då läraren ofta har fler aspekter som den använder sig av vid bedömingen utav en elevtext. Läraren, till skillnad från grammatikgranskaren, bedömmer en text på aspekter så som hur väl texten hör till en viss genre, dess struktur och ordvariation. Denna uppsats utforskar hur pass väl dessa aspekter går att anpassas till NLP (Natural Language Processing) och implementerar de som passar väl in i en regelbaserad lösning som heter Granska.

Orthography Standardization in Arabic Dialects Abstract Christian Cayralat1 1 Charles University Spontaneous orthography in Arabic dialects poses one of the biggest ob- stacles in the way of Dialectal Arabic NLP applications. As the Arab world enjoys a wide array of these widely spoken and recently written, non-standard, low-resource varieties, this thesis presents a detailed account of this relatively overlooked phenomenon. It sets out to show that continuously creating addi- tional noise-free, manually standardized corpora of Dialectal Arabic does not free us from the shackles of non-standard (spontaneous) orthography. Because real-world data will most often come in a noisy format, it also investigates ways to ease the amount of noise in textual data. As a proof of concept, we restrict ourselves to one of the dialectal varieties, namely, Lebanese Arabic. It also strives to gain a better understanding of the nature of the noise and its distri- bution. All of this is done by leveraging various spelling correction and morpho- logical tagging neural architectures in a multi-task setting, and by annotating a Lebanese Arabic corpus for spontaneous orthography standardization, and morphological segmentation and tagging, among other features. Additionally, a detailed taxonomy of spelling inconsistencies for...

Climate change poses a significant threat to bioenergy production, impacting plant’s phenology and physiological performance. Investigating the adaptation of bioenergy crops like Populus is crucial for sustaining production. Populus, known for its genetic variation and ease of study, offers insights into tree responses to climate change. My research, part of the Advancing Populus Pathways in the Southeast (APPS) project, focuses on various Populus genotypes across multiple growing seasons, exploring phenology under different management strategies. Planting Populus across two sites, namely Monroe and Pontotoc, allows for the examination of genotype responses to climate change factors, particularly in terms of phenology and productivity. Factors like parentage provenance and temperature fluctuations influence budburst timing. Additionally, management practices, such as coppicing, significantly affect budburst, with coppiced trees showing delayed timing (five to ten days) compared to non-coppiced ones. Cold spell damage during budbreak reveals vulnerability, with northern provenances exhibiting greater resilience. Understanding such events is vital for tailored management. Cold spells not only impact initial budbreak but also alter leaf phenology and canopy dynamics, affecting overall productivity. Genotypes exhibit varied responses to rising temperatures and CO2 levels, influenced by their parentage. Trees with northern provenance, for instance, display higher photosynthetic capacity, but may face thermal stress under certain temperature increases. Conversely, southern genotypes demonstrate moderate photosynthetic capacity, but showcase better adaptation to heat, offering potential for breeding resilient varieties. Leaf traits serve as proxies for biomass production and water use efficiency prediction, aiding in genotype screening. Mechanisms like self-shading and leaf movability influence responses to environmental changes. For instance, self-shading helps regulate leaf temperature, thereby enhancing photosynthetic performance, albeit with some trade-offs. Elevated CO2 levels enhance water use efficiency, but determining whole-tree water use efficiency requires integration of various methods. While leaf-level measurements correlate with whole-tree water use efficiency, an integrated approach, combining leaf-level gas exchange and isotopic measurements, shows promise. In conclusion, understanding Populus responses to climate change is crucial for sustainable bioenergy production in the southeastern United States. Insights into phenology, productivity, and adaptation mechanisms offer avenues for management and breeding strategies, ensuring resilience amidst shifting climates.

Background. Previous research suggests that individuals experiencing DSM-IV panic attacks (PA) are at increased risk for various forms of psychopathology, including anxiety, depressive and substance use disorders. However, little is known regarding whether the sole occurrence of fearful spells (FS-only; distressing spells of anxiety with less than four panic symptoms and/or lacking crescendo in symptom onset) similarly elevates the risk for subsequent psychopathology and could therefore be promising to identify high-risk groups for targeted preventive interventions. Thus, the current dissertation thesis aims to examine (a) whether FS-only predict incident mental disorders in addition to full-blown PA and whether their associations with subsequent psychopathology differ from those obtained for PA, (b) whether FS-only, PA, and panic disorder (PD) share similar etiologies, (c) which characteristics of initial FS/PA and other risk factors predict a progression to more severe panic pathology and other mental disorders, and (d) whether help-seeking/potential treatment in individuals with panic alters the risk for subsequent psychopathology. Methods. A representative community sample of adolescents and young adults (N=3021, aged 14-24 at baseline) was prospectively followed up in up to three assessment waves over a time period of up to 10 years. FS-only, PA, PD, and other mental disorders were assessed at each assessment wave using the DSM-IV-M-CIDI. Additional modules/questionnaires were used to assess characteristics of initial FS/PA (T1/T2), potential risk factors, and help-seeking/potential treatment. Logistic regressions were applied to test associations (Odds Ratios, OR) of FS-only and PA at baseline with incident mental disorders at follow-up as well as respective interactive effects with help-seeking at baseline. Associations (Hazard Ratios, HR) of putative risk factors with the onset of panic pathology (FS-only, PA, and PD) or the onset of subsequent anxiety/depressive vs. substance use disorders in those with panic pathology (aggregated data across assessment waves) were estimated with Cox regressions. Multinomial logistic regressions were used to test associations of initial FS/PA characteristics (aggregated from T1 and T2) with PA and PD (lifetime incidences aggregated across assessment waves). Results. FS-only at baseline predicted incident anxiety and depressive disorders at follow-up (OR 1.59-4.36), while PA at baseline predicted incident anxiety, depressive, and substance use disorders at follow-up (OR 2.08-8.75; reference group: No FS/PA). Merely any anxiety disorder (OR=3.26) and alcohol abuse/dependence (OR=2.26) were significantly more strongly associated with PA than with FS-only. Female sex, parental anxiety disorders, parental depressive disorders, behavioral inhibition, harm avoidance, lower coping efficacy, and parental rejection predicted FS-only, PA, and PD (HR 1.2-3.0), whereas the associations with other risk factors partially differed for FS-only, PA, and PD and tended to be more pronounced for PA and PD than for FS-only. Alcohol consumption, use of drugs/medication, and physical illness as perceived reasons for the initial FS/PA were associated with the occurrence of full-blown PA (without PD, OR 2.46-5.44), while feelings of anxiety/depression and having always been anxious/nervous as perceived reasons for the initial FS/PA, appraising the initial FS/PA as terrible and long-term irritating/burdensome, subsequent feelings of depression, avoidance of situations/places, and consumption of medication, alcohol, or drugs were associated with the development of PD (OR 2.64-4.15). A longer duration until “feeling okay again” was associated with both PA and PD (OR 1.29-1.63 per category). Moreover, partially different risk constellations in subjects with panic pathology (FS/PA/PD) predicted the onset of subsequent anxiety/depressive vs. substance use disorders. Panic pathology (FS/PA) and help-seeking/potential treatment at baseline interacted on predicting incident PD (OR=0.09) and depression (OR=0.22) at follow-up in a way that panic pathology only predicted these disorders in individuals not seeking help at baseline. Conclusions. Findings suggest that individuals with FS-only are at similar risk of developing subsequent psychopathology compared to individuals with full-blown PA. Specific initial FS/PA characteristics and additional risk factors may be used to identify sub-groups of individuals with panic pathology, which are at particular risk of progressing to more severe panic pathology or other mental disorders and might therefore profit from supplemental outcome-related preventive interventions in addition to panic-specific treatment. Future research may replicate the current findings and test the efficacy of targeted preventive interventions in panickers at elevated risk for PD and other forms of psychopathology. / Theoretischer Hintergrund. Auf Grundlage früherer Forschungsbefunde ist anzunehmen, dass Personen mit DSM-IV-Panikattacken (PA) ein erhöhtes Risiko für zahlreiche psychische Störungen, einschließlich Angst-, depressiver und Substanzstörungen, aufweisen. Unklar ist jedoch, ob das alleinige Auftreten von Fearful Spells (FS-only, Angstanfälle mit weniger als vier Paniksymptomen und/oder fehlendem Crescendo in der Symptomentwicklung) das Risiko für Psychopathologie in ähnlicher Weise erhöht und hilfreich sein könnte, um Hochrisikogruppen für Präventivinterventionen zu identifizieren. Innerhalb der vorliegenden Dissertation wird daher untersucht, (a) ob FS-only zusätzlich zu PA inzidente psychische Störungen vorhersagen und ob sich Unterschiede in den Assoziationen von FS-only vs. PA mit nachfolgender Psychopathologie ergeben, (b) ob FS-only, PA und Panikstörung (PS) ähnliche Ätiologien teilen, (c) welche Merkmale initialer FS/PA und welche anderen Risikofaktoren die Entwicklung schwerer Panikpathologie und weiterer psychischer Störungen vorhersagen und (d) ob Hilfesuchverhalten/potenzielle Behandlung bei Personen mit Panik das Risiko für nachfolgende Psychopathologie verändert. Methodik. Eine repräsentative Bevölkerungsstichprobe Jugendlicher und junger Erwachsener (N=3021, 14-24 Jahre zur Baseline-Erhebung) wurde in bis zu drei Erhebungswellen über einen Zeitraum von bis zu 10 Jahren untersucht. FS-only, PA, PS und andere psychische Störungen wurden zu jeder Erhebungswelle mithilfe des DSM-IV-M-CIDI erfasst. Merkmale initialer FS/PA (T1/T2), mögliche Risikofaktoren sowie Hilfesuchverhalten/potenzielle Behandlung wurden mit weiteren Modulen und Fragebögen erhoben. Mithilfe logistischer Regressionen wurden Assoziationen (Odds Ratios, OR) von FS-only und PA zu Baseline mit inzidenten psychischen Störungen zum Follow-Up sowie diesbezügliche Interaktionen mit Hilfesuchverhalten zu Baseline getestet. Zusammenhänge zwischen möglichen Risikofaktoren und dem Auftreten von Panikpathologie (FS-only, PA und PS) bzw. nachfolgender Angst-/depressiver und Substanzstörungen bei Personen mit Panikpathologie (Verwendung von über die Erhebungswellen hinweg aggregierter Daten) wurden mithilfe von Cox-Regressionen geschätzt. Multinomiale logistische Regressionen wurden genutzt, um Assoziationen von Merkmalen initialer FS/PA (aggregiert über T1 und T2) mit PA und PS (über die Erhebungswellen hinweg aggregierte Lebenszeitinzidenzen) zu erfassen. Ergebnisse. FS-only zu Baseline sagten inzidente Angst- und depressive Störungen zum Follow-Up vorher (OR 1.59-4.36), wohingegen PA zu Baseline inzidente Angst-, depressive und Substanzstörungen zum Follow-Up vorhersagten (OR 2.08-8.75; Referenzkategorie: Keine FS/PA). Lediglich irgendeine Angststörung (OR=3.26) und Alkoholmissbrauch/-abhängigkeit (OR=2.26) waren signifikant stärker mit PA als mit FS-only assoziiert. Weibliches Geschlecht, elterliche Angst- und depressive Störungen, Verhaltenshemmung, Schadensvermeidung, geringere Coping-Erwartung und elterliche Zurückweisung sagten FS-only, PA und PS vorher (HR 1.2-3.0), während sich teils unterschiedliche Assoziationen anderer Risikofaktoren mit FS-only, PA und PS ergaben, die tendenziell stärker für PA und PS als für FS-only waren. Alkoholkonsum, Drogen-/Medikamentengebrauch und körperliche Erkrankungen als wahrgenommene Gründe für die initiale FS/PA waren mit dem Auftreten vollständiger PA assoziiert (ohne PS; OR 2.46-5.44), während Gefühle von Angst/Depression und die Einschätzung schon immer ängstlich/nervös gewesen zu sein als wahrgenommene Gründe für die initiale FS/PA, die Bewertung der initialen FS/PA als schrecklich und langfristig verunsichernd/belastend, nachfolgende Gefühle von Niedergeschlagenheit, Vermeidung von Situationen/Orten und Konsum von Medikamenten, Alkohol oder Drogen mit der Entwicklung von PS assoziiert waren (OR 2.64-4.15). Eine längere Dauer bis sich die betroffene Person wieder vollständig in Ordnung fühlte war sowohl mit PA als auch mit PS assoziiert (OR 1.29-1.63 pro Kategorie). Weiterhin sagten teils unterschiedliche Risikokonstellationen bei Personen mit Panikpathologie (FS/PA/PS) die nachfolgende Entstehung von Angst-/depressiven und Substanzstörungen vorher. Panikpathologie (FS/PA) und Hilfesuchverhalten/potenzielle Behandlung zu Baseline interagierten bei der Vorhersage von inzidenter PS (OR=0.09) und Depression (OR=0.22) zum Follow-Up; d.h. das Vorhandensein von Panikpathologie sagte diese Störungen nur bei Personen ohne, nicht aber bei Personen mit Hilfesuchverhalten zu Baseline vorher. Schlussfolgerungen. Die vorliegenden Ergebnisse implizieren, dass Personen mit FS-only im Vergleich zu Personen mit vollständigen PA ein ähnliches Risiko für die Entwicklung nachfolgender Psychopathologie aufweisen. Spezifische Merkmale initialer FS/PA und zusätzliche Risikofaktoren könnten zur Identifikation von Sub-Gruppen von Personen mit Panik genutzt werden, die sich durch ein besonderes Risiko für schwergradige Panikpathologie und andere psychische Störungen auszeichnen und demzufolge von Outcome-bezogenen Präventionen (ergänzend zu Panik-spezifischer Intervention) profitieren könnten. Zukünftige Studien sollten die vorliegenden Befunde replizieren und die Effektivität gezielter Präventivinterventionen bei Personen mit erhöhtem Risiko für PS und andere psychische Störungen testen.

The growth rings of eastern redcedar (Juniperus virginiana L.) often contain a high frequency of false intra-annual growth bands, which complicates the dendrochronology of this species. However, exactly dated false rings replicated among many trees can reflect major weather changes during the growing season. Sixty-one trees from two sites (Oklahoma and Kansas) were dated and used to compile replicated chronologies of false rings at both locations extending from AD 1700–2000. False-ring events during the modern instrumental era were compared with the daily weather data from nearby stations. Significant false-ring events occurred at both locations during years that experienced a dramatic late-growing season weather reversal, when an extended period of high temperatures and drought was followed by prolonged cool and wet conditions. Synoptic weather maps for these events indicate that all ten replicated false-ring events in the instrumental era occurred during the highly unseasonable penetration of a cold front into the region. However, none of the significant false-ring events occurred in the same year at both sites. These separate false-ring chronologies indicate that there may be phenological differences in the timing of radial growth in redcedar between Kansas and Oklahoma, and that the weather conditions responsible for false-ring formation often occur at the mesoscale and do not often impact central Kansas and northcentral Oklahoma simultaneously.

The goal of this thesis is to explore the area of natural language correction and to design and implement neural network models for a range of tasks ranging from general grammar correction to the specific task of diacritization. The thesis opens with a description of existing approaches to natural language correction. Existing datasets are reviewed and two new datasets are introduced: a manually annotated dataset for grammatical error correction based on CzeSL (Czech as a Second Language) and an automatically created spelling correction dataset. The main part of the thesis then presents design and implementation of three models, and evaluates them on several natural language correction datasets. In comparison to existing statistical systems, the proposed models learn all knowledge from training data; therefore, they do not require an error model or a candidate generation mechanism to be manually set, neither they need any additional language information such as a part of speech tags. Our models significantly outperform existing systems on the diacritization task. Considering the spelling and basic grammar correction tasks for Czech, our models achieve the best results for two out of the three datasets. Finally, considering the general grammatical correction for English, our models achieve results which are...

Due to the increased usage of technology and its indicated aid in writing acquisition, it is important to investigate the effects of spell-checkers on the English language. Thus, this essay has conducted a quantitative study to ascertain if there has been an improvement or regression in English spelling with the aim of gathering an indication of if and how spelling has evolved and changed with the development of spell-checkers. This study intended to answer two main questions: “Has spelling improved after spell-checkers were invented?” and “Can spell-checkers be seen as an aid in helping people learn how to spell better?”. Texts from before the development of spell-checkers and texts from after were utilized and searched for possible misspellings, to identify whether spelling has improved or not. The main finding was that there was a numerical difference between the two groups of texts, with the older texts containing an average of 43% misspellings as opposed to the newer texts which comprised an average of 7% misspellings. Thus, it was concluded that with the emergence of spell-checkers, spelling has improved. In relation to the second question, this research detected that although spelling mistakes have decreased, certain misspellings and errors are occurring, such as errors in transposition and omission, indicating that spell- checkers might not in fact be an aid in improving spelling competence. However, more data is required with regard to the second question, thus the answer remains inconclusive, with the need for further data to reach an assertive answer.