The harm done by tests of significance

Three historical episodes in which the application of null hypothesis significance testing (NHST) led to the mis-interpretation of data are described. It is argued that the pervasive use of this statistical ritual impedes the accumulation of knowledge and is unfit for use.     

Relationships between milk urea and production, nutrition, and fertility traits in Israeli dairy herds

The objectives of this study were to identify and evaluate production and environmental factors that influence milk urea (MU) in Israeli dairy herds, to analyze the relationships between MU concentration and nutritional variables, and to examine a possible association between MU and pregnancy rate (PR). Production and environmental data were obtained from the Israeli Dairy Herd Improvement (DHI) Center (n = 1,279,600). Programmed total mixed rations (feeds and quantities) on milk-test day were collected from 42 dairy herds. Data on 36,073 cows that were inseminated close to milk-test day and pregnancy diagnosis results were obtained from the DHI data bank. Highly significant positive relationships were found between MU concentration and milk yield and fat percentage; relationships between MU and milk total protein percentage and somatic cell count were negative. Milk urea levels were higher during the summer months and were higher for adult cows. These levels increased as lactation progressed. Milk urea was positively associated with dietary levels of crude protein, ruminal digestible protein, and neutral detergent fiber contents; it was negatively associated with ration energy and nonstructural carbohydrate contents. Significant influences of specific feeds on MU were detected. A significant negative association was found between MU level and PR. Least squares means for PR for cows in the lowest and highest MU quartiles were 38.4 and 36.1%, respectively. Increasing levels of MU were negatively related to reproductive performance of dairy cows, but the risk of nonpregnancy caused by high levels of MU was lower than reported in previous studies.     

Rotenone-Induced 4-HNE Aggresome Formation and Degradation in HL-1 Cardiomyocytes: Role of Autophagy Flux

Reactive oxygen species (ROS) cause oxidative stress by generating reactive aldehydes known as 4-hydroxynonenal (4-HNE). 4-HNE modifies protein via covalent adduction; however, little is known about the degradation mechanism of 4-HNE-adducted proteins. Autophagy is a dynamic process that maintains cellular homeostasis by removing damaged organelles and proteins. In this study, we determined the role of a superoxide dismutase (SOD) mimetic MnTnBuOE-2-PyP⁵⁺ (MnP, BMX-001) on rotenone-induced 4-HNE aggresome degradation in HL-1 cardiomyocytes. A rotenone treatment (500 nM) given for 24 h demonstrated both increased ROS and 4-HNE aggresome accumulation in HL-1 cardiomyocytes. In addition, cardiomyocytes treated with rotenone displayed an increase in the autophagy marker LC3-II, as shown by immunoblotting and immunofluorescence. A pre-treatment with MnP (20 µM) for 24 h attenuated rotenone-induced ROS formation. An MnP pre-treatment showed decreased 4-HNE aggresomes and LC3-II formation. A rotenone-induced increase in autophagosomes was attenuated by a pre-treatment with MnP, as shown by fluorescent-tagged LC3 (tfLC3). Rotenone increased tubulin hyperacetylation through the ROS-mediated pathway, which was attenuated by MnP. The disruption of autophagy caused HL-1 cell death because a 3-methyladenine inhibitor of autophagosomes caused reduced cell death. Yet, rapamycin, an inducer of autophagy, increased cell death. These results indicated that a pre-treatment with MnP decreased rotenone-induced 4-HNE aggresomes by enhancing the degradation process.     

Engineering biodegradable polymer blends containing flame retardant-coated starch/nanoparticles

We have shown that the addition of resorcinol di(phenyl phosphate) (RDP)-coated starch can improve the compatibility to either Ecoflex or poly(lactic acid) (PLA). The increased compatibilization enhanced the tensile properties such as yield strength and impact toughness. In particular, we examined the effect of addition of RDP-coated starch on thermal responses of a blend of Ecoflex/PLA. We found that the combination of RDP-coated starches with nanoclays could render the blends self-extinguishing since they are formed as a shell-like chars on the exposure surface against heat, which can prevent the melt polymers against dripping. With an examination on the scanning transmission X-ray microscopy (STXM) images of the blends, the Ecoflex domains were well dispersed in the PLA matrix, while the domains became smaller when the RDP-coated starch was added. Moreover, we demonstrated that the introduction of either flat-like or tube-like clays could provide an increase of interfacial area on the RDP-coated starch surfaces, where each polymer chain preferentially segregates to either the starch or the clay surface. Thus, large complex in-situ grafts with polymers can be formed at the interfaces. Additionally, the complex in-situ grafts could influence flammability of the blends. We have shown that the addition of RDP-coated clays can decrease the mass loss rate of Ecoflex/Starch blends, while a lot of nanofiber are formed on the chars surface, which are entangled each other with the clay platelets. The mechanical properties of the chars structures were examined by nano-indentation, where a good elastic chars formation could keep the internal pressures built up with decomposed gases from melt polymers as well as ductility of the chars could play an important role on releasing the internal gases through small vents on its surface, steadily where a good elastic and ductile chars formation could require keeping the internal pressures built up with decomposed gases from melt polymers.     

Inactivation and surface interactions of MS-2 bacteriophage in a TiO2 photoelectrocatalytic reactor

Inactivation of MS-2 bacteriophage in a TiO₂ photoelectrocatalytic system was evaluated, wherein TiO₂ particles were coated onto an indium tin oxide (ITO) electrode and an electrical potential was applied under black light blue (BLB) irradiation. MS-2 phage inactivation was greatly enhanced by anodic potential, whereas cathodic potential completely inhibited inactivation. Experiments performed with radical scavengers showed that inactivation was primarily caused by hydroxyl radicals, both in the bulk phase and on the TiO₂ surface. Application of positive potential to the electrode was found to result in two distinct beneficial effects: (i) electrostatic attraction between the negatively charged viral capsid and catalyst surface, causing improved usage of surface-bound hydroxyl radical, in comparison to conventional TiO₂ photocatalytic disinfection; and (ii) higher reactive oxygen species production. Results also suggest that inactivation of various microorganisms including Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Bacillus subtilis spores and Cryptosporidium parvum oocyst was enhanced via positive potential induction to TiO₂.     

A new method of ensuring even distribution of a fumigant in flexible fumigation chambers using external fans

A series of commercial fumigations to control narcissus fly larvae in bulbs for export was carried out to determine the effectiveness of a gas distribution method that utilizes external fans positioned outside the chamber. The principle is to generate air motion using the flexibility of the PVC liner. This is done by directing an air-flow along the walls of the liner, thus creating a ripple motion that generates an internal turbulence which mixes the air with the fumigant inside the chamber. With fans placed opposite the corners of the bubble it was possible to divide the airflow along all sides of the bubble wall. Methyl bromide concentrations recorded over the 4-h fumigation period, were compared with previous results obtained when the fumigant was mixed by recirculation. The use of external fans in combination with flexible PVC chambers enabled an even gas distribution to be achieved within the chambers in 1-1.5 h whereas under recirculation, even distribution was not reached during the entire 4-h fumigation period. Post-fumigation mortality data on narcissus fly larvae revealed 100% kill.     

Aircraft emissions of methane and nitrous oxide during the alternative aviation fuel experiment

Given the predicted growth of aviation and the recent developments of alternative aviation fuels, quantifying methane (CH(4)) and nitrous oxide (N(2)O) emission ratios for various aircraft engines and fuels can help constrain projected impacts of aviation on the Earth's radiative balance. Fuel-based emission indices for CH(4) and N(2)O were quantified from CFM56-2C1 engines aboard the NASA DC-8 aircraft during the first Alternative Aviation Fuel Experiment (AAFEX-I) in 2009. The measurements of JP-8 fuel combustion products indicate that at low thrust engine states (idle and taxi, or 4% and 7% maximum rated thrusts, respectively) the engines emit both CH(4) and N(2)O at a mean ± 1σ rate of 170 ± 160 mg CH(4) (kg Fuel)(-1) and 110 ± 50 mg N(2)O (kg Fuel)(-1), respectively. At higher thrust levels corresponding to greater fuel flow and higher engine temperatures, CH(4) concentrations in engine exhaust were lower than ambient concentrations. Average emission indices for JP-8 fuel combusted at engine thrusts between 30% and 100% of maximum rating were -54 ± 33 mg CH(4) (kg Fuel)(-1) and 32 ± 18 mg N(2)O (kg Fuel)(-1), where the negative sign indicates consumption of atmospheric CH(4) in the engine. Emission factors for the synthetic Fischer-Tropsch fuels were statistically indistinguishable from those for JP-8.     

Comparative characterisation of durian,mango and avocado

The aim of this investigation was to determine the nutritional and bioactive properties of relatively less investigated exotic fruit durian (Durio zibethinus Murr.) and to compare these indices with widely used mango (Mangifera indica L.) and avocado (Persea americana). For this purpose HPLC, three‐dimensional fluorescence (3D‐FL), several radical scavenging assays and multivariate factor analysis were used. It was found a similarity in acetone extracts between durian and mango in the contents of polyphenols (1.66 ± 0.08, 1.48 ± 0.05, mg GAE g^?1 DW, respectively), and in some antioxidant assays such as ABTS (11.98 ± 0.5, 12.24 ± 0.5, μm TE g^?1DW, respectively) and DPPH (5.61 ± 0.3, 5.22 ± 0.2, μm TE g^?1 DW, respectively). Durian and avocado were similar in the contents of polyphenols, and ABTS and DPPH values in water and in methanol extracts, respectively. Based on the obtained results the nutritional and bioactive properties of durian are comparable with those indices in mango and avocado. In conclusion, durian can be recommended as a part of disease prevented diets.     

Ultrasonic assessment of rhinostomy size following external dacryocystorhinostomy

AIM: To assess the dimensions and patency of the surgical epithelial fistula after external dacryocystorhinostomy, using B mode ultrasonography to define the postoperative soft tissue anastomosis. METHODS: 12 patients undergoing 16 external dacryocystorhinostomies, with the creation of large osteotomies, were included in a prospective study. The horizontal and vertical dimensions of the bone ostium was recorded during surgery and compared with the ultrasonographic dimensions of the soft tissue anastomosis at 1 day, 2 weeks, and 6 months after surgery. Functional patency was confirmed with dye testing and irrigation. RESULTS: Compared with an osteotomy of between 100 and 380 mm2 (mean 235 mm2), the soft tissue anastomosis on the day after surgery was, in all cases, markedly smaller (72-252 mm2; mean 144 mm2, or 61% of the bone window). The soft tissue anastomosis decreased to between 8 and 208 mm2 (mean 98 mm2; 68% of immediate postoperative value) at 2 weeks and 3-208 mm2 (mean 71 mm2; 49% of immediate postoperative value) at 6 months. 14 of the 16 (88%) dacryocystorhinostomies were functional at the end of the study, the two failures being associated with marked contracture of the soft tissue anastomosis; the outcome of surgery correlated significantly with the area of the anastomosis at 2 weeks (chi 2 = 16.3; p < 0.01) and at 6 months (chi 2 = 16.0, p = 0.01). CONCLUSIONS: B mode ultrasonography provides a simple and effective method for assessing the size of the soft tissue anastomosis after external dacryocystorhinostomy and there is a significant reduction in size after surgery, to which the functional outcome of surgery appears related. As the initial soft tissue anastomosis cannot be larger than (and is, on average, about 60% of) the area of the osteotomy, this emphasises the paramount importance of a large rhinostomy to the success of lacrimal surgery.     

Model reduction of uncertain systems retaining the uncertainty structure

Model reduction of high order linear-in-parameters discrete-time systems is considered. The main novelty of the paper is that the coefficients of the original system model are assumed to be known only within given intervals, and the coefficients of the derived reduced order model are also obtained in intervals, such that the complex value sets of the uncertain original and reduced models will be optimally close to each other on the unit circle. The issue of inclusion of one value set in another is also addressed in the paper. The meaning of model reduction is defined for linear-in-parameters systems. The algorithm for obtaining the value sets of such systems is derived in the paper. Then, applying a novel approach, the infinity norm of “distance” between two polygons representing the original and the reduced uncertain systems is minimized. A noteworthy point is that by a special definition of this distance the problem is formulated as a linear semi-infinite programming problem with linear constraints, thus reducing significantly the computational complexity. Numerical example is provided.