Kraichnan–Leith–Batchelor similarity theory and two-dimensional inverse cascades

We study the scaling properties and Kraichnan–Leith–Batchelor (KLB) theory of forced inverse cascades in generalized two-dimensional (2D) fluids (α-turbulence models) simulated at resolution 8192x8192. We consider α=1 (surface quasigeostrophic flow), α=2 (2D Euler flow) and α=3. The forcing scale is well resolved, a direct cascade is present and there is no large-scale dissipation. Coherent vortices spanning a range of sizes, most larger than the forcing scale, are present for both α=1 and α=2. The active scalar field for α=3 contains comparatively few and small vortices. The energy spectral slopes in the inverse cascade are steeper than the KLB prediction −(7−α)/3 in all three systems. Since we stop the simulations well before the cascades have reached the domain scale, vortex formation and spectral steepening are not due to condensation effects; nor are they caused by large-scale dissipation, which is absent. One- and two-point p.d.f.s, hyperflatness factors and structure functions indicate that the inverse cascades are intermittent and non-Gaussian over much of the inertial range for α=1 and α=2, while the α=3 inverse cascade is much closer to Gaussian and non-intermittent. For α=3 the steep spectrum is close to that associated with enstrophy equipartition. Continuous wavelet analysis shows approximate KLB scaling ℰ(k)∝k−2 (α=1) and ℰ(k)∝k−5/3 (α=2) in the interstitial regions between the coherent vortices. Our results demonstrate that coherent vortex formation (α=1 and α=2) and non-realizability (α=3) cause 2D inverse cascades to deviate from the KLB predictions, but that the flow between the vortices exhibits KLB scaling and non-intermittent statistics for α=1 and α=2.

Dual drive series actuator

Industrial robotic manipulators can be found in most factories today. Their tasks are accomplished through actively moving, placing and assembling parts. This movement is facilitated by actuators that apply a torque in response to a command signal. The presence of friction and possibly backlash have instigated the development of sophisticated compensation and control methods in order to achieve the desired performance may that be accurate motion tracking, fast movement or in fact contact with the environment. This thesis presents a dual drive actuator design that is capable of physically linearising friction and hence eliminating the need for complex compensation algorithms. A number of mathematical models are derived that allow for the simulation of the actuator dynamics. The actuator may be constructed using geared dc motors, in which case the benefits of torque magnification is retained whilst the increased non-linear friction effects are also linearised. An additional benefit of the actuator is the high quality, low latency output position signal provided by the differencing of the two drive positions. Due to this and the linearised nature of friction, the actuator is well suited for low velocity, stop-start applications, micro-manipulation and even in hard-contact tasks. There are, however, disadvantages to its design. When idle, the device uses power whilst many other, single drive actuators do not. Also the complexity of the models mean that parameterisation is difficult. Management of start-up conditions still pose a challenge.

Mapping power law distributions in digital health social networks: methods, interpretations, and practical implications

BACKGROUND: Social networks are common in digital health. A new stream of research is beginning to investigate the mechanisms of digital health social networks (DHSNs), how they are structured, how they function, and how their growth can be nurtured and managed. DHSNs increase in value when additional content is added, and the structure of networks may resemble the characteristics of power laws. Power laws are contrary to traditional Gaussian averages in that they demonstrate correlated phenomena. OBJECTIVES: The objective of this study is to investigate whether the distribution frequency in four DHSNs can be characterized as following a power law. A second objective is to describe the method used to determine the comparison. METHODS: Data from four DHSNs—Alcohol Help Center (AHC), Depression Center (DC), Panic Center (PC), and Stop Smoking Center (SSC)—were compared to power law distributions. To assist future researchers and managers, the 5-step methodology used to analyze and compare datasets is described. RESULTS: All four DHSNs were found to have right-skewed distributions, indicating the data were not normally distributed. When power trend lines were added to each frequency distribution, R(2) values indicated that, to a very high degree, the variance in post frequencies can be explained by actor rank (AHC .962, DC .975, PC .969, SSC .95). Spearman correlations provided further indication of the strength and statistical significance of the relationship (AHC .987. DC .967, PC .983, SSC .993, P<.001). CONCLUSIONS: This is the first study to investigate power distributions across multiple DHSNs, each addressing a unique condition. Results indicate that despite vast differences in theme, content, and length of existence, DHSNs follow properties of power laws. The structure of DHSNs is important as it gives insight to researchers and managers into the nature and mechanisms of network functionality. The 5-step process undertaken to compare actor contribution patterns can be replicated in networks that are managed by other organizations, and we conjecture that patterns observed in this study could be found in other DHSNs. Future research should analyze network growth over time and examine the characteristics and survival rates of superusers.

Interim analyses and sequential designs in phase III studies

Recruitment of patients to a clinical trial usually occurs over a period of time, resulting in the steady accumulation of data throughout the trial's duration. Yet, according to traditional statistical methods, the sample size of the trial should be determined in advance, and data collected on all subjects before analysis proceeds. For ethical and economic reasons, the technique of sequential testing has been developed to enable the examination of data at a series of interim analyses. The aim is to stop recruitment to the study as soon as there is sufficient evidence to reach a firm conclusion. In this paper we present the advantages and disadvantages of conducting interim analyses in phase III clinical trials, together with the key steps to enable the successful implementation of sequential methods in this setting. Examples are given of completed trials, which have been carried out sequentially, and references to relevant literature and software are provided.

Meta-analysis to integrate effect sizes within a paper: Possible misuse and Type-1 error inflation

In recent years an increasing number of papers have employed meta-analysis to integrate effect sizes of researchers’ own series of studies within a single paper (“internal meta-analysis”). Although this approach has the obvious advantage of obtaining narrower confidence intervals, we show that it could inadvertently inflate false-positive rates if researchers are motivated to use internal meta-analysis in order to obtain a significant overall effect. Specifically, if one decides whether to stop or continue a further replication experiment depending on the significance of the results in an internal meta-analysis, false-positive rates would increase beyond the nominal level. We conducted a set of Monte-Carlo simulations to demonstrate our argument, and provided a literature review to gauge awareness and prevalence of this issue. Furthermore, we made several recommendations when using internal meta-analysis to make a judgment on statistical significance.

Clinical evaluation and COL2A1 gene analysis in 21 Brazilian families with Stickler syndrome: Identification of novel mutations, further genotype/phenotype correlation, and its implications for the diagnosis

We present clinical and molecular evaluation from a large cohort of patients with Stickler syndrome: 78 individuals from 21 unrelated Brazilian families. The patients were selected in a Hospital with a craniofacial dysmorphology assistance service and clinical diagnosis was based on the presence of cleft palate associated to facial and ocular anomalies of Stickler syndrome. Analysis of COL2A1 gene revealed 9 novel and 4 previously described pathogenic mutations. Except for the mutation c.556G>T (p.Gly186X), all the others were located in the triple helical domain. We did not find genotype/phenotype correlation in relation to type and position of the mutation in the triple helical domain. However, a significantly higher proportion of myopia in patients with mutations located in this domain was observed in relation to those with the mutation in the non-tripe helical domain (c.556G>T; P < 0.04). A trend towards a higher prevalence of glaucoma, although not statistically significant, was observed in the presence of the mutation c.556G>T. It is possible. that this mutation alters the splicing of the mRNA instead of only creating a premature stop codon and therefore it can lead to protein products of different ocular effects. One novel DNA variation (c.1266+7G>C) occurs near a splice site and it was observed to co-segregate with the phenotype in one of the two families with this DNA variation. As in silico analysis predicted that the c.1266+7G>C DNA variation can affect the efficiency of the splicing, we still cannot rule it out as non-pathogenic. Our study also showed that ascertainment through cleft palate associated to other craniofacial signs can be very efficient for identification of Stickler syndrome patients. Still, high frequency of familial cases and high frequency of underdevelopment of distal lateral tibial epiphyses observed in our patients suggested that the inclusion of this information can improve the clinical diagnosis of Stickler syndrome. (C) 2008 Elsevier Masson SAS. All rights reserved.

Mariner-like elements in Rhynchosciara americana (Sciaridae) genome: molecular and cytological aspects

Two mariner-like elements, Ramar1 and Ramar2, are described in the genome of Rhynchosciara americana, whose nucleotide consensus sequences were derived from multiple defective copies containing deletions, frame shifts and stop codons. Ramar1 contains several conserved amino acid blocks which were identified, including a specific D,D(34)D signature motif. Ramar2 is a defective mariner-like element, which contains a deletion overlapping in most of the internal region of the transposase ORF while its extremities remain intact. Predicted transposase sequences demonstrated that Ramar1 and Ramar2 phylogenetically present high identity to mariner-like elements of mauritiana subfamily. Southern blot analysis indicated that Ramar1 is widely represented in the genome of Rhynchosciara americana. In situ hybridizations showed Ramar1 localized in several chromosome regions, mainly in pericentromeric heterochromatin and their boundaries, while Ramar2 appeared as a single band in chromosome A.

Oxidative stress protection of Trypanosomes requires selenophosphate synthase

Selenoproteins are characterized by the incorporation of at least one amino acid selenocysteine (Sec-U) encoded by in-frame UGA stop codons. These proteins, as well as the components of the Sec synthesis pathway, are present in members of the bacteria, archaea and eukaryote domains. Although not a ubiquitous pathway in all organisms, it was also identified in several protozoa, including the Kinetoplastida. Genetic evidence has indicated that the pathway is non-essential to the survival of Trypanosoma growing in non-stressed conditions. By analyzing the effects of RNA interference of the Trypanosoma brucei selenophosphate synthetase SPS2, we found a requirement under sub-optimal growth conditions. The present work shows that SPS2 is involved in oxidative stress protection of the parasite and its absence severely hampers the parasite survival in the presence of an oxidizing environment that results in an apoptotic-like phenotype and cell death. (C) 2011 Elsevier B.V. All rights reserved.

Beteendestudier och miljöberikning av gnagare

It is often challenging to create a new enrichment program for any animal. This is especially true with the additional challenge that I wanted to use only naturalistic enrichment, and I’m working with animals some of which are nocturnal. Even with a many hurdles, a little bit of enrichment can do a big difference and make a big difference in activity levels of the animals. Eskilstuna parkens zoo have a house called the MUSeum housing four kinds of rodents. Rodents are generally much more active at night and spend much of the day sleeping out of sight of the public. One of the goals of starting an enrichment program was to increase the animal’s activity throughout the day to provide an improved guest experience. Many of the guests would stop briefly at the exhibit only seeing the empty exhibit, unaware of that there were animals there. Before starting an enrichment program, I wanted to determine how the rodent was spending their time. By observing the animals’ behaviour for 15 minutes a day at various times throughout the day, for a total of 15 observations, I was able to construct an activity budget for their behaviour. The results obtained were, as expected, that the rodents spent a lot of time resting. By enrichment both with food and the temperature we were able to take the activity to another level, and several new behaviours were observed.

Language Dominance in Early and Late Bilinguals

The proposed presentation is a progress report from a project which is aimed at establishing some phonetic correlates of language dominance in various kinds of bilingual situations. The current object of study is Swedish students starting in classes which prepare for the International Baccalaureate (IB) programme. The IB classes in Sweden are taught in English, except for classes in Swedish and foreign languages. This means that after they enter the programme the students are exposed to and speak a good deal more English than previously.The assumption made by many students that they will, on the one hand not “damage” their Swedish, and on the other will dramatically improve their English simply by attending an English-medium school will be tested. The linguistic background of the students studied and their reasons for choosing the IB programme will be established. Their English and Swedish proficiency will be tested according to various parameters (native-like syntax, perceived foreign accent, the timing of vowels and consonants in VC sequences, vocabulary mobilisation) on arrival at the school, and again after one and three years at the school. The initial recordings are now underway.In a preliminary study involving just three young people who were bilingual in Swedish and English, the timing of the pronunciation of (C)VC syllables in Swedish and English was studied. The results of this investigation indicate that it may be possible to establish language dominance in bilingual speakers using timing data. It was found that the three subjects differed systematically in their pronunciation of the target words. One subject (15 years old), who was apparently native-like in both languages, had the V-C timing of both Swedish and English words of a native speaker of English. His brother (17 years old), who had a noticeable Swedish accent in English, pronounced both Swedish and English words in this respect like a native speaker of Swedish. The boys’ sister (9 years old) apparently had native-like timing in both languages.

Mätning och utvärdering av PM brännaren

The PM-brännaren (pellets burner) have on commission by the company been measured and evaluated in the combustion laboratory of SERC. The objective was to measure the perform-ance and the emissions of CO and NO for three different combustion powers and for start and stop conditions. The burner have been mounted in the Bionett-boiler from Ariterm and been adjusted by the company. The boiler has been connected to a buffer store that admits firing during long period with constant inlet temperature to the boiler. The measurements have been performed by operating the boiler on constant power until stationary conditions are reached. Thereafter the following two hours of operation have been evaluated. The results show that the burner fulfils the limit values for Blauer Engel labelling and the proposed limit values for Nordic Eco labelling. The measured concentration of NO is far below all organisations limit values for NOx. Concerning the start and stop emissions there are no demands from organisa-tions to compare with, but comparing with other boilers measured at SERC, the CO emissions from PM-brännaren is in the same order of magnitude.

Communication in Smoking Cessation and Self-management : a study at Nurse-led COPD-clinics in Primary Health Care

ABSTRACTThe general aim of this thesis was to investigate behavioral change communication at nurse-led chronic obstructive pulmonary disease (COPD) clinics in primary health care, focusing on communication in self-management and smoking cessation for patients with COPD.Designs: Observational, prospective observational and experimental designs were used.Methods: To explore and describe the structure and content of self-management education and smoking cessation communication, consultations between patients (n=30) and nurses (n=7) were videotaped and analyzed with three instruments: Consulting Map (CM), the Motivational Interviewing Treatment Integrity (MITI) scale and the Client Language Assessment in Motivational Interviewing (CLAMI). To examine the effects of structured self-management education, patients with COPD (n=52) were randomized in an intervention and a control group. Patients’ quality of life (QoL), knowledge about COPD and smoking cessation were examined with a questionnaire on knowledge about COPD and smoking habits and with St. George’s Respiratory Questionnaire, addressing QoL. Results: The findings from the videotaped consultations showed that communication about the reasons for consultation mainly concerned medical and physical problems and (to a certain extent) patients´ perceptions. Two consultations ended with shared understanding, but none of the patients received an individual treatment-plan. In the smoking cessation communication the nurses did only to a small extent evoke patients’ reasons for change, fostered collaboration and supported patients’ autonomy. The nurses provided a lot of information (42%), asked closed (21%) rather than open questions (3%), made simpler (14%) rather than complex (2%) reflections and used MI non-adherent (16%) rather than MI-adherent (5%) behavior. Most of the patients’ utterances in the communication were neutral either toward or away from smoking cessation (59%), utterances about reason (desire, ability and need) were 40%, taking steps 1% and commitment to stop smoking 0%. The number of patients who stopped smoking, and patients’ knowledge about the disease and their QoL, was increased by structured self-management education and smoking cessation in collaboration between the patient, nurse and physician and, when necessary, a physiotherapist, a dietician, an occupational therapist and/or a medical social worker.Conclusion The communication at nurse-led COPD clinics rarely involved the patients in shared understanding and responsibility and concerned patients’ fears, worries and problems only to a limited extent. The results also showed that nurses had difficulties in attaining proficiency in behavioral change communication. Structured self-management education showed positive effects on patients’ perceived QoL, on the number of patients who quit smoking and on patients’ knowledge about COPD.

Improvement of Routine Test Process of High Voltage Power Capacitors

The capacitor test process at ABB Capacitors in Ludvika must be improved to meet future demands for high voltage products. To find a solution to how to improve the test process, an investigation was performed to establish which parts of the process are used and how they operate. Several parts which can improves the process were identified. One of them was selected to be improved in correlation with the subject, mechanical engineering. Four concepts were generated and decision matrixes were used to systematically select the best concept. By improving the process several benefits has been added to the process. More units are able to be tested and lead time is reduced. As the lead time is reduced the cost for each unit is reduced, workers will work less hours for the same amount of tested units, future work to further improve the process is also identified. The selected concept was concept 1, the sway stop concept. This concept is used to reduce the sway of the capacitors as they have entered the test facility, the box. By improving this part of the test process a time saving of 20 seconds per unit can be achieved, equivalent to 7% time reduction. This can be compared to an additional 1400 units each year.

Al-Mahdi - Gestalt och budskap : En litteraturstudie jämförande sudanesisk Mahdi och indisk Mahdi inom islam

Followers of three world religions, Judaism, Christianity and Islam are waiting for the Messiah. Muslims are even waiting for aspiritual leader al-Mahdi. Two different persons claimed the title of al-Mahdi, at the end of the nineteenth century. Theyappeared almost at the same time, at the totally different places of the earth, with a completely different message and underthe rule of the British colonial power. The aim of the study is to compare the both religious figures, Mirza Ghulam Ahmadfrom India and Muhammad Ahmad from Sudan regarding their different messages, to illustrate the social, political andreligious factors that lead to the entirely different profile and image of these two men and how their organizations havedeveloped after their death up till today. The result shows that the Sudanese Mahdi Muhammad Ahmad claimed hisMahdiship in the year 1881. He became a political leader in a time when Sudan was under the rule of a colonial power. Hetook advantage of the religion for personal purposes and tried to liberate his native country Sudan. The contemporaryMuslim clergy criticized him for his claim because the content of the Hadith traditions did not support his claim ofMahdiship. He maintained his sole right for the interpretation of religion and of the laws of Sharia. He made changes even inthe chief pillars of Islam by asserting that Jehad with sword was more imperative than the pilgrimage journey to Mecca. Heasserted that the Prophet Muhammad himself had entrusted him to launch the holy war against the non-believers. He hadimmense ambitions which were never fulfilled since he suddenly died four years after his claim for Mahdiship, in June 1885.This day his followers are organized as a political party in Sudan with a modest roll in the Sudanese politics. The IndianMahdi Mirza Ghulam Ahmad claimed in 1889 to be Mahdi, Mujaddid, Muhaddas, Messiah and a Prophet at a time of socialand political peace, though Islam as a religion was firmly pushed by the Hindu and Christian missionaries. He had no politicalambitions at all and was utterly loyal to the British colonial power. His mission was to crush the Cross and to demonstrateIslam’s excellence over all the religions of the world through overwhelming arguments. He proclaimed that Jesus was humanand a Prophet and not the son of God. Jesus survived from the cross and died a natural death after he had lived for manyyears. Ahmad claimed that God had commanded him to put stop to the religious wars. The contemporary Muslim clergyblamed him for being an imposter, melancholic and hypochondriac who had self invented the divine revelations. He died year1908, nineteen years after his claim and the communion he found is established today in more than hundred countries of theworld. Reasons for the breakdown of mission of the Sudanese Mahdi were that his objectives were political and he challengedthe colonial power with the sword. Another decisive factor was his sudden death merely four years after the beginning of hismission. Reasons for the success of Indian Mahdi were that his objectives were purely religious and he was wholly loyal to theforeign government. He survived nineteen years after the beginning of his mission which made it possible for him to create acommunion based on solid grounds. His followers continued on the same path and never engaged in local politics where everthey lived. For further studies it will be of great interest to study the life of Mirza Ghulam Ahmad and objectively examine thearguments he presented in support of his divine appointment. Furthermore it is enriching to study the organization andactivities of the Ahmadiyya Muslim community to explore if they are in accordance with the basic principles of Ahmad.

Elbesparing med pelletkaminer och solvärme i direktelvärmda småhus

The aim of this study was to investigate how electricallyheated houses can be converted to using wood pellet and solarheating. There are a large number of wood pellet stoves on themarket. Many stoves have a water jacket, which gives anopportunity to distribute the heat to domestic hot water and aradiator heating system. Three typical Swedish houses with electric resistanceheating have been studied. Fourteen different system conceptsusing wood pellet stoves and solar heating systems have beenevaluated. The systems and the houses have been simulated indetail using TRNSYS. The houses have been divided in up to 10different zones and heat transfer by air circulation throughdoorways and open doors have been simulated. The pellet stoveswere simulated using a recently developed TRNSYS component,which models the start- and stop phases, emissions and thedynamic behaviour of the stoves. The model also calculates theCO-emissions. Simulations were made with one stove without awater jacket and two stoves with different fractions of thegenerated heat distributed in the water circuit. Simulations show that the electricity savings using a pelletstove are greatly affected by the house plan, the systemchoice, if the internal doors are open or closed and thedesired level of comfort. Installing a stove with awater-jacket connected to a radiator system and a hot waterstorage has the advantage that heat can be transferred todomestic hot water and be distributed to other rooms. Suchsystems lead to greater electricity savings, especially inhouses having a traditional layout. It was found that not allrooms needed radiators and that it was more effective in mostcases t use a stove with a higher fraction of the heatdistributed by the water circuit. The economic investigation shows that installing a woodpellet stove without a water jacket gives the lowest totalenergy- and capital costs in the house with an open plan (fortoday's energy prices and the simulated comfort criteria). Inthe houses with a traditional layout a pellet stove givesslightly higher costs than the reference house having onlyelectrical resistance heating due to the fact that less heatingcan be replaced. The concepts including stoves with a waterjacket all give higher costs than the reference system, but theconcept closest to be economical is a system with a bufferstore, a stove with a high fraction of the heat distributed bythe water circuit, a new water radiator heating system and asolar collector. Losses from stoves can be divided into: flue gas lossesincluding leakage air flow when the stove is not in operation;losses during start and stop phases; and losses due to a highair factor. An increased efficiency of the stoves is importantboth from a private economical point of view, but also from theperspective that there can be a lack of bio fuel in the nearfuture also in Sweden. From this point of view it is alsoimportant to utilize as much solar heat as possible. Theutilization of solar heat is low in the simulated systems,depending on the lack of space for a large buffer store. The simulations have shown that the annual efficiency ismuch lower that the nominal efficiency at full power. Thesimulations have also shown that changing the control principlefor the stove can improve efficiency and reduce theCO-emissions. Today's most common control principle for stovesis the on/off control, which results in many starts and stopsand thereby high CO-emissions. A more advanced control varyingthe heating rate from maximum to minimum to keep a constantroom temperature reduces the number of starts and stops andthereby the emissions. Also the efficiency can be higher withsuch a control, and the room temperature will be kept at a moreconstant temperature providing a higher comfort.