The corotating variation of the north-south anisotropy of cosmic rays

Correlation analysis on the relation of the north-south (N-S) anisotropy of cosmic rays, observed by the Nagoya multidirectional meson telescope, with the interplanetary magnetic field (IMP) as well the solar wind velocity within solar Carrington rotation for the period 1971 to 1976 is discussed. It is found that the N-S anisotropy of cosmic rays correlates quite well with the Bx component of the IMF. The correlation coefficient is nearly equal to 0.8

H-statistic with winsorized modified one-step M-estimator as central tendency measure

Two-sample independent t-test and ANOVA are classical procedures which are widely used to test the equality of two groups and more than two groups respectively. However, these parametric procedures are easily affected by non-normality, becoming more obvious when heterogeneity of variances and unbalanced group sizes exist. It is well known that the violation in the assumption of the tests will lead to inflation in Type I error rate and decreasing in the power of test. Nonparametric procedures like Mann-Whitney and Kruskal-Wallis may be the alternative to the parametric procedures, however, loss of information occur due to the ranking data. In mitigating these problems, robust procedures can be used as the other alternative. One of the procedures is H-statistic. When used with modified one-step M-estimator (MOM), the test statistic (MOM-H) produces good control of Type I error rate even under small sample size but inconsistent under certain conditions investigated. Furthermore, power of test is low which might be due to the trimming process. In this study, MOM was winsorized (WMOM) to retain the original sample size. The Hstatistic when combines with WMOM as the central tendency measure (WMOM-H) shows better control of Type I error rate as compared to MOM-H especially under balanced design regardless of the shape of distributions. It also performs well under highly skewed and heavy tailed distribution for unbalanced design. On top of that, WMOM-H also generates better power value, as compared to MOM-H and ANOVA under most of the conditions investigated. WMOM-H also has better control of Type I error rates with no liberal value (>0.075) compared to the parametric (t-test and ANOVA) and nonparametric (Mann-Whitney and Kruskal-Wallis) procedures. In general, this study demonstrates that winsorization process (WMOM) is able to improve the performance of H-statistic in terms of controlling Type I error rate and increasing power of test

Ruptured abdominal aortic aneurysm, a “two-hit” ischemia/reperfusion injury: Evidence from an analysis of oxidative products

AbstractPurpose: Ruptured abdominal aortic aneurysm (RAAA) remains a lethal condition despite improvements in perioperative care. The consequences of RAAA are hypothesized to result from a combination of two ischemia/reperfusion events: hemorrhagic shock and lower torso ischemia. Ischemia/reperfusion results in tissue injury by diverse mechanisms, which include oxygen free radical–mediated injury produced from activated neutrophils, xanthine oxidase, and mitochondria. Oxygen-free radicals attack membrane lipids, resulting in membrane and subsequently cellular dysfunction that contributes to postoperative organ injury/failure. The purpose of this investigation was to quantify the oxidative injury that occurs as a result of the ischemia/reperfusion events in RAAAs and elective AAAs. Methods: Blood samples were taken from 22 patients for elective AAA repair and from 14 patients for RAAA repair during the perioperative period. Plasma F2 -isoprostanes were extracted, purified, and measured with an enzyme immunoassay. Aldehydes and acyloins were purified and quantified. Neutrophil oxidative burst was measured in response to a receptor independent stimulus (phorbol 12-myristate 13-acetate) with luminol-based chemiluminescence. Results: Plasma from patients with RAAAs showed significantly elevated F2 -isoprostane levels on arrival at hospital and were significantly elevated as compared with the levels of patients for elective repair throughout the perioperative period (two-way analysis of variance, P < .0001). Multiple regression showed a significant relationship between the phagocyte oxidative activity and F2 -isoprostane levels (P < .013). Total acyloin levels were significantly higher in patients with RAAAs as compared with the levels in elective cases. Conclusion: The F2 -isoprostane levels, specific markers of lipid peroxidation, showed that patients with RAAAs had two phases of oxidative injury: before arrival at hospital and after surgery. The significant relationship between the postoperative increases in F2 -isoprostane levels and the neutrophil oxidant production implicates neutrophils in the oxidative injury that occurs after RAAA. New therapeutic interventions that attenuate neutrophil-mediated oxidant injury during reperfusion may decrease organ failure and ultimately mortality in patients with RAAAs. (J Vasc Surg 1999;30:219-28.

Tracking science : an alternative for those excluded by citizen science

Abstract: In response to recent discussion about terminology, we propose “tracking science” as a term that is more inclusive than citizen science. Our suggestion is set against a postcolonial political background and large-scale migrations, in which “citizen” is becoming an increasingly contentious term. As a diverse group of authors from several continents, our priority is to deliberate a term that is all-inclusive, so that it could be adopted by everyone who participates in science or contributes to scientific knowledge, regardless of socio-cultural background. For example, current citizen science terms used for Indigenous knowledge imply that such practitioners belong to a sub-group that is other, and therefore marginalized. Our definition for “tracking science” does not exclude Indigenous peoples and their knowledge contributions and may provide a space for those who currently participate in citizen science, but want to contribute, explore, and/or operate beyond..

Probing molecular interactions with methylene blue derivatized self-assembled monolayers

The emergence of stratified and personalised medicine and the associated need for highly multiplexed detection strategies are driving the development of innovative sensor technology. Electronic immunosensor arrays capable of label-free and highly parallel monitoring of ligand binding have emerged as a particularly promising technology capable of meeting these new diagnostic challenges. In this study, we present an approach for interrogating molecular interactions electronically using redox active molecular monolayers. Specifically, we have synthesised self-assembled molecular monolayers assembled from long-chain alkanethiols (LCAT) incorporating oligoethyleneglycol (OEG) linkers that can be derivatized with a range of functional groups, including the redox active molecule methylene blue. Critically, we show that the electron transport properties of this redox-active monolayer are highly sensitive to the electrochemical environment, including the local concentration of protons and the electrostatic potential at the plane of electron transfer. Using a combination of cyclic voltammetry and QCM-D to study in detail the behaviour of the monolayer during functionalisation and analyte binding, we demonstrate that these redox properties can be exploited for the electrochemical sensing of molecular interactions (biotin–avidin in our case) on SAMs. Given the versatility of LCAT-OEG monolayers, in terms of linker lengths, choice of functional group, and ability to create mixed component layers and the straight-forward assembly of mixed SAMs of high quality, our electrochemical sensing approach forms an excellent and generic label-free platform for probing a wide range of molecular interactions