A longitudinal study of changing characteristics of self-reported taste and smell alterations in patients treated for lung cancer

AbstractPurposeTaste and smell alterations (TSAs) are common symptoms in patients with cancer that may interfere with nutritional intake and quality of life. In this study, we explore and describe how characteristics of self-reported TSAs change in individuals with lung cancer over time using a multiple case study approach to present longitudinal data from individuals.MethodsPatients under investigation for lung cancer were recruited from one university hospital in Sweden. The 52 patients providing data eligible for the analyses presented here were those treated for primary lung cancer with three measurement time-points, of which one was prior to treatment and two after treatment start. Four self-report instruments were used for data collection. These included the Taste and Smell Survey, used to characterize TSAs for each individual at the three time-points and instruments measuring nutritional status, symptom burden and well-being. Three patient cases are described in detail to illustrate variation in individual experiences of TSAs.ResultsThe characteristics of the TSAs experienced changed over time for many of the individuals in this study, including those undergoing surgery or stereotactic radiotherapy. The case descriptions show how the individual experiences of TSAs and the impact on daily life of these symptoms not only depend on TSA characteristics, but may be influenced by contextual factors, e.g. other symptoms and life situation.ConclusionsOur results suggest that healthcare professionals need to consider the variation in characteristics of TSAs among and within patients over time, and be attentive to individual experiences of TSAs

Knowledge and practice among dietitians in four Western European countries regarding malnutrition, starvation, cachexia and sarcopenia

Adequate distinction between malnutrition, starvation, cachexia and sarcopenia is important in clinical care. Despite the overlap in physical characteristics, differences in etiology have therapeutical and prognostic implications. We aimed to determine whether dietitians in selected European countries have ‘proper knowledge’ of malnutrition, starvation, cachexia and sarcopenia, and use terminology accordingly

Monto Carlo Tree Search in Real Time Strategy Games with Applications to Starcraft 2

This thesis presents an architecture for an agent that can play the real-time strategy game Starcraft 2 (SC2) by applying Monte Carlo Tree Search (MCTS) together with genetic algorithms and machine learning methods. Together with the MCTS search, a light-weight and accurate combat simulator for SC2 as well as a build order optimizer are presented as independent modules. While MCTS has been well studied for turn-based games such as Go and Chess, its performance has so far been less explored in the context of real-time games. Using machine learning and planning methods in real-time strategy games without requiring long training times has proven to be a challenge. This thesis explores how a model based approach, based on the rules of the game, can be used to achieve a well performing agent.Denna uppsats presenterar en arkitektur för ett program som kan spela realtidsspelet Starcraft 2 (SC2) genom att använda Monte Carlo Tree Search (MCTS) tillsammans med genetiska algoritmer och maskininlärningsmetoder. Tillsammans med MCTS-sökningen så presenteras också en snabb och exakt stridssimulator för SC2 samt en optimeringsalgoritm för bygg-ordningar som separata moduler. MCTS has studerats mycket inom turordningsbaserade spel som till exempel Go och Schack, däremot så har det utforskats mindre när det kommer till realtidsspel. Att använda maskininlärning och planeringsalgoritmer i realtidsstrategispel utan att kräva långa träningstider har visat sig vara en utmaning. Denna uppsats utforskar hur ett modellbaserat tillvägagångssätt, baserat på reglerna för spelet, kan användas för att skapa ett bra presterande program

Nutritional support among cancer patients enrolled in palliative home care services

Nutritional problems are common in palliative cancer care. Little is known about nutritional problems and nutritional support in home care. AIMS: The primary aim of this thesis was to investigate experiences of nutritional problems and home nutritional support, with a special focus on home parenteral nutrition (HPN), from the perspectives of cancer patients and their family members. Further aims were to investigate the prevalence of nutritional risk and use of nutritional support among cancer patients enrolled in palliative home care services. METHODS: Two explorative studies were conducted. The first was a qualitative interview study with 13 cancer patients with experience of HPN and 11 of their family members. In a second study 621 patients with various malignant diseases participated in structured telephone interviews. These patients were recruited from all 21 palliative home care services in the Stockholm region. RESULTS: Paper I: Patients and family members described the nutritional situation prior to HPN as a source of worry and often desperation. Patients reported that they wanted and tried to eat, but were unable to do so. Family members experienced powerlessness and frustration when they could not enable the patient to eat. A lack of attention to nutritional problems by hospital staff was described. HPN was offered at a point when patients and family no longer felt able to solve the nutritional problems themselves. Paper II: The most salient experience of HPN described by patients and family members was a sense of relief and security that nutritional needs were met. This was said to have a direct and positive effect on quality of life, and on body weight, level of energy and strength, and activity. Positive statements about HPN were often coupled to the benefits of being enrolled in palliative home care. The most salient negative effect of HPN was described as related to restrictions in family life and social contacts. However, benefits of the HPN treatment were generally said to outweigh negative aspects. Paper III: Sixty-eight percent of the 621 interviewed patients were scored as at nutritional risk according to the modified version of NRS-2002. Nutritional support, mainly oral nutritional supplements, was used by 55% of the patients. Fourteen percent of all patients used artificial nutrition, i.e. HPN or home enternal tube feeding (HETF). Use of nutritional support was related to low BMI and severe weight loss, and was more common in patients with shorter survival times. Paper IV: HPN was more common (11%) than HETF (3%). Artificial nutrition was usually introduced more than four months before death. Three of four HPN recipients also had solid food intake. HPN use was associated with eating difficulties, nausea/vomiting, and fatigue rather than gastrointestinal problems per se. HETF was generally used for patients with problems chewing and/or swallowing. CONCLUSIONS: A desperate and chaotic nutritional situation in the family led to a willingness to accept HPN. The patients and their family members experienced physical, social and psychological benefits of HPN. Nutritional support was used to treat already malnourished patients with short survival times, rather than to prevent malnutrition. Contrary to existing guidelines, HPN was used to supplement oral intake, and not only for patients with a nonfunctioning gastrointestinal tract. A more structured approach to nutritional issues taking life expectancy and psychosocial aspects into consideration could help identify potential candidates for nutritional support. There remains a need to investigate how to best individualise use of nutritional support for patients in palliative phases

Implementation and Verification of Sorting Algorithms with the Interactive Theorem Prover HOL

As the world becomes increasingly reliant on technology and the technology becomes increasingly complex, ensuring software correctness is becoming both increasingly important and difficult. Methods like software testing are rarely enough to guarantee that a program will always work as intended. Formal methods offer attractive alternatives. Using formal methods, properties about software can be unambiguously proven for all possible input. In this project we use the interactive theorem prover HOL to define and formally verify a simplified version of the popular sorting algorithm Timsort. We also formalize the time-complexity property and prove the best-case time-complexity of the simplified algorithm. We intended to use the CakeML compiler to generate verified machine code from the HOL definitions, and thus produce an end-to-end verified executable program. Because of time constraints, we instead generated ML code using EmitML. The resulting ML code is not guaranteed to retain the proven properties during execution. The project demonstrates how sorting algorithms can be formally verified and provides parts that could be re-used to verify the actual Timsort algorithm

Monto Carlo Tree Search in Real Time Strategy Games with Applications to Starcraft 2

This thesis presents an architecture for an agent that can play the real-time strategy game Starcraft 2 (SC2) by applying Monte Carlo Tree Search (MCTS) together with genetic algorithms and machine learning methods. Together with the MCTS search, a light-weight and accurate combat simulator for SC2 as well as a build order optimizer are presented as independent modules. While MCTS has been well studied for turn-based games such as Go and Chess, its performance has so far been less explored in the context of real-time games. Using machine learning and planning methods in real-time strategy games without requiring long training times has proven to be a challenge. This thesis explores how a model based approach, based on the rules of the game, can be used to achieve a well performing agent.Denna uppsats presenterar en arkitektur för ett program som kan spela realtidsspelet Starcraft 2 (SC2) genom att använda Monte Carlo Tree Search (MCTS) tillsammans med genetiska algoritmer och maskininlärningsmetoder. Tillsammans med MCTS-sökningen så presenteras också en snabb och exakt stridssimulator för SC2 samt en optimeringsalgoritm för bygg-ordningar som separata moduler. MCTS has studerats mycket inom turordningsbaserade spel som till exempel Go och Schack, däremot så har det utforskats mindre när det kommer till realtidsspel. Att använda maskininlärning och planeringsalgoritmer i realtidsstrategispel utan att kräva långa träningstider har visat sig vara en utmaning. Denna uppsats utforskar hur ett modellbaserat tillvägagångssätt, baserat på reglerna för spelet, kan användas för att skapa ett bra presterande program

Implementation and Verification of Sorting Algorithms with the Interactive Theorem Prover HOL

As the world becomes increasingly reliant on technology and the technology becomes increasingly complex, ensuring software correctness is becoming both increasingly important and difficult. Methods like software testing are rarely enough to guarantee that a program will always work as intended. Formal methods offer attractive alternatives. Using formal methods, properties about software can be unambiguously proven for all possible input. In this project we use the interactive theorem prover HOL to define and formally verify a simplified version of the popular sorting algorithm Timsort. We also formalize the time-complexity property and prove the best-case time-complexity of the simplified algorithm. We intended to use the CakeML compiler to generate verified machine code from the HOL definitions, and thus produce an end-to-end verified executable program. Because of time constraints, we instead generated ML code using EmitML. The resulting ML code is not guaranteed to retain the proven properties during execution. The project demonstrates how sorting algorithms can be formally verified and provides parts that could be re-used to verify the actual Timsort algorithm