Reliable Experimental Design Research Articles

Generalizability of Results from Randomized Controlled Trials in Post-Stroke Physiotherapy.

Purpose: The randomized controlled trial (RCT) is considered a reliable experimental design, able to detect the effect of an intervention. However, a criticism frequently levelled at RCTs by clinicians is their lack of generalizability. This study aimed to evaluate the generalizability of findings from RCTs of physiotherapy interventions for individuals with stroke. Method: A sample of RCTs of physiotherapy interventions after stroke indexed in the PEDro database was selected, and the reported inclusion and exclusion criteria were analyzed. Results: We reviewed 100 articles, which included 7,366 participants (41.6% women, with a mean weighted age of 65.5 years). The most frequent criteria for exclusion were comorbidity (83%), cognitive impairments (69%), communication skills (55%), recurrent stroke (53%), low functional level (47%) and being elderly (25%). Conclusions: A variety of cohorts of individuals who have had a stroke are excluded from RCTs published in the field of physiotherapy. Because they represent a substantial proportion of the real-world population with stroke, and consequently treated in clinical practice, more vulnerable cohorts of participants should be included in RCTs.

A Study on the Role of Clostridium Saccharoperbutylacetonicum N1-4 (ATCC 13564) in Producing Fermentative Hydrogen

Abstract Comparing with other biological processes, a technological method associated with bio-energy has been developed as the result of the high possibility of fermentative hydrogen productivity; In addition, restricted fossil fuel has been also substituted. The production of fermentative hydrogen is a complicated process influenced by different factors including different kinds of micro-organisms, initial concentration of substrate, inoculum size, initial pH of the medium, concentration of nutrients metals, etc. Thus, the present study is aiming at detecting such different agents to obtain the highest yield of hydrogen and progressing its operation through improving the efficiency of these agents by reliable experimental design. Clostridium saccharoperbutylacetonicum N1-4(ATCC 13564) was applied to produce hydrogen in a batch manner. The highest yield of hydrogen has been resulted in 3.016 mol of hydrogen per mol glucose with production rate of 3.281 mole of hydrogen per hour at 37 °C, 10 % of inoculums size, 10 g/L of an initial glucose concentration, initial pH of medium of 6.5, 30 mg/L of FeSO4.7H2O. Furthermore, the experimental results were compared to kinetic model of Gompertz. Moreover, it was found out that the experimental issues were compatible with this kinetic model with the regression coefficient values of 0.989.

Reliability of forearm oxygen uptake during handgrip exercise: assessment by ultrasonography and venous blood gas.

Assessment of forearm oxygen uptake (V˙O2) during handgrip exercise is a keenly investigated concept for observing small muscle mass metabolism. Although a combination of Doppler ultrasound measurements of brachial artery blood flow (Q˙) and blood gas drawn from a deep forearm vein has been utilized to calculate forearm V˙O2 for more than two decades, the applicability of this experimental design may benefit from a thorough evaluation of its reliability during graded exercise. Therefore, we evaluated the reliability of this technique during incremental handgrip exercise in ten healthy young (24 ± 3(SD) years.) males. V˙O2 and work rate (WR) exhibited a linear relationship (1.0 W: 43.8 ± 10.1 mL·min−1; 1.5 W: 53.8 ± 14.1 mL·min−1; 2.0 W: 63.4 ± 16.3 mL·min−1; 2.5 W: 72.2 ± 17.6 mL·min−1; 3.0 W: 79.2 ± 18.6 mL·min−1; r = 0.65, P < 0.01). In turn, V˙O2 was strongly associated with Q˙ (1.0 W: 359 ± 86 mL·min−1; 1.5 W: 431 ± 112 mL·min−1; 2.0 W: 490 ± 123 mL·min−1; 2.5 W: 556 ± 112 mL·min−1; 3.0 W: 622 ± 131 mL·min−1; r = 0.96; P < 0.01), whereas arteriovenous oxygen difference (a‐vO2diff) remained constant following all WRs (123 ± 11–130 ± 10 mL·L−1). Average V˙O2 test–retest difference was −0.4 mL·min−1 with ±2SD limits of agreement (LOA) of 8.4 and −9.2 mL·min−1, respectively, whereas coefficients of variation (CVs) ranged from 4–7%. Accordingly, test–retest Q˙ difference was 11.9 mL·min−1 (LOA: 84.1 mL·min−1; −60.4 mL·min−1) with CVs between 4 and 7%. Test–retest difference for a‐vO 2diff was −0.28 mL·dL−1 (LOA: 1.26mL·dL −1; −1.82 mL·dL−1) with 3–5% CVs. In conclusion, our results revealed that forearm V˙O2 determination by Doppler ultrasound and direct venous sampling is linearly related to WR, and a reliable experimental design across a range of exercise intensities.

Biomarkers in the prevention and follow-up of workers exposed to asbestos.

Although in most developed countries the use of asbestos is banned, there is still a consistent portion of the world where asbestos extraction, trading and manufacturing of asbestos-made products is largely diffuse. Worldwide, hundreds of millions of people are at risk of developing an asbestos caused disease because of occupational, environmental or domestic exposure. The WHO estimates that asbestos is responsible for more than 100,000 deaths yearly. This scenario has prompted the research on biomarkers potentially useful for early diagnosis, prognosis and preventive programs on exposed population as well. Here we reviewed the up-to-date literature on this field of research highlighting that along with mesothelin and osteopontin (OPN), some more recently investigated molecules, such as high mobility group box 1 (HMGB1) protein, fibulin-3 and some miRNAs showed very promising. Most of the carried-out studies showed an interesting diagnostic and prognostic performance of some biomarkers, but since they usually lack adequate either specificity or sensitivity, their use in screening or in preventive programs is still not recommended on a routine basis. However, this review suggests the need for more reliable experimental design involving larger population and preferring longitudinal screening of asbestos exposed individuals rather than a single baseline assessment investigation. In addition, given their better diagnostic accuracy, the use of panels including several biomarkers is highly recommended.

Framework for Reliable Experimental Design (FRED): A research framework to ensure the dependable interpretation of digital data for digital forensics

The establishment of fact forms the cornerstone of any forensic discipline, with digital analysis being no exception. Practitioners are under an obligation as expert witnesses to provide factual accounts of digital scenarios, which must be underpinned by robust knowledge and evidential findings. To achieve this level of reliability, investigatory research must be suitably planned, implemented and analysed in a way which instills confidence in the accuracy of any findings. This is particularly important as digital forensic organisations are now facing the impending requirement to have acquired ISO/IEC 17025 accreditation. This article proposes the Framework for Reliable Experimental Design (FRED) to support those engaged in the field of digital forensics research to contribute reliable, robust findings. FRED focuses on the underpinning procedures involved within undertaking the reverse engineering of digital data structures and the process of extracting and interpreting digital content in a reliable way. The proposed framework is designed to be a resource for those operating within the digital forensic field, both in industry and academia, to support and develop research best practice within the discipline.

Mastoid vibration affects dynamic postural control during gait in healthy older adults

Vestibular disorders are difficult to diagnose early due to the lack of a systematic assessment. Our previous work has developed a reliable experimental design and the result shows promising results that vestibular sensory input while walking could be affected through mastoid vibration (MV) and changes are in the direction of motion. In the present paper, we wanted to extend this work to older adults and investigate how manipulating sensory input through mastoid vibration (MV) could affect dynamic postural control during walking. Three levels of MV (none, unilateral, and bilateral) applied via vibrating elements placed on the mastoid processes were combined with the Locomotor Sensory Organization Test (LSOT) paradigm to challenge the visual and somatosensory systems. We hypothesized that the MV would affect sway variability during walking in older adults. Our results revealed that MV significantly not only increased the amount of sway variability but also decreased the temporal structure of sway variability only in anterior-posterior direction. Importantly, the bilateral MV stimulation generally produced larger effects than the unilateral. This is an important finding that confirmed our experimental design and the results produced could guide a more reliable screening of vestibular system deterioration.

A comparison of AdaBoost algorithms for time series forecast combination

Recently, combination algorithms from machine learning classification have been extended to time series regression, most notably seven variants of the popular AdaBoost algorithm. Despite their theoretical promise their empirical accuracy in forecasting has not yet been assessed, either against each other or against any established approaches of forecast combination, model selection, or statistical benchmark algorithms. Also, none of the algorithms have been assessed on a representative set of empirical data, using only few synthetic time series. We remedy this omission by conducting a rigorous empirical evaluation using a representative set of 111 industry time series and a valid and reliable experimental design. We develop a full-factorial design over derived Boosting meta-parameters, creating 42 novel Boosting variants, and create a further 47 novel Boosting variants using research insights from forecast combination. Experiments show that only few Boosting meta-parameters increase accuracy, while meta-parameters derived from forecast combination research outperform others.

A new experimental design method to optimize formulations focusing on a lubricant for hydrophilic matrix tablets

A robust experimental design method was developed with the well-established response surface methodology and time series modeling to facilitate the formulation development process with magnesium stearate incorporated into hydrophilic matrix tablets. Two directional analyses and a time-oriented model were utilized to optimize the experimental responses. Evaluations of tablet gelation and drug release were conducted with two factors x1 and x2: one was a formulation factor (the amount of magnesium stearate) and the other was a processing factor (mixing time), respectively. Moreover, different batch sizes (100 and 500 tablet batches) were also evaluated to investigate an effect of batch size. The selected input control factors were arranged in a mixture simplex lattice design with 13 experimental runs. The obtained optimal settings of magnesium stearate for gelation were 0.46 g, 2.76 min (mixing time) for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The optimal settings for drug release were 0.33 g, 7.99 min for a 100 tablet batch and 1.54 g, 6.51 min for a 500 tablet batch. The exact ratio and mixing time of magnesium stearate could be formulated according to the resulting hydrophilic matrix tablet properties. The newly designed experimental method provided very useful information for characterizing significant factors and hence to obtain optimum formulations allowing for a systematic and reliable experimental design method.

Surgically produced congenital diaphragmatic hernia in fetal rabbits

Animal models of congenital diaphragmatic hernia (CDH) still are indispensable for the evolution of knowledge related to this disease and to fetal surgery in general. The lamb has provided the most reliable experimental design thus far. Considering the possible advantages of using rabbits (rather than lambs) namely lower costs, no need of special veterinary facilities, smaller body size, year-round availability, higher number of fetuses per pregnancy, and shorter gestational period, a successful model of CDH was developed in fetal rabbits. Sixteen pregnant New Zealand rabbits underwent hysterotomy and fetal operation. Group 1 (6 does) underwent surgery on gestational day 20 and group 2 (10 does) on gestational day 24 or 25. The normal full gestation time is 31 to 33 days. In group 1, the CDH was created by transabdominal puncture and dilatation of the fetal diaphragm. In group 2, the CDH was created through open thoracotomy, either left or right. The fetuses were delivered by cesarean section on gestational day 30. The overall fetal survival rate was 0 for group 1 and 70% for group 2. All operated fetuses in group 2 that were born alive had CDH. The histological morphometric examinations (radial alveolar count after sustained lung expansion) of the normal and operated fetuses in group 2 showed pulmonary hypoplasia in all the lungs on the same side as the CDH (statistical analysis was performed using the Neuman-Keuls test and analysis of variance; the significance level was set at .05). There was significant arterial wall thickening in the parenchyma of the lungs ipsilateral and contralateral to the CDH (analysis by the Kruskall-Wallis test; significance level set at .05). This study demonstrates that (1) CDH can be surgically created in fetal rabbits, with high survival rates, (2) either left or right CDH is feasible in fetal rabbits, and (3) experimental CDH is associated with pulmonary hypoplasia in New Zealand rabbits operated on at 24 or 25 days' gestation. The rabbit may provide a reliable and practical experimental model of CDH.

Note on the Flavor of the Egg and Meat of the Hens Fed Yeast Grown on n-Paraffin

Yeast grown on n-paraffin, which will be called just the yeast hereafter, has specific flavor common to yeast. Although many preliminary trials just tasting the meat of broiler and hen fed a diet containing high level of the yeast and egg laid by hens fed the diet revealed no detectable change in flavor of the meat and egg, the flavor specific to the yeast in feed is suspected to be transferred to the meat and egg, making these products unfavorable for food. Accordingly, sensory test based on more reliable experimental design was carried out to find whether the meat and egg of hens fed the yeast has any specific and detectable flavor.