Calculation of the oxygen isotope discrimination factor for studying plant respiration

Measurement of discrimination against 18O during dark respiration in plants is currently accepted as the only reliable method of estimating the partitioning of electrons between the cytochrome and alternative pathways. In this paper, we review the theory of the technique and its application to a gas-phase system. We extend it to include sampling effects and show that the isotope discrimination factor, D, is calculated as –dln(1 + δ)/dlnO*, where δ is isotopic composition of the substrate oxygen and O*=[O2]/[N2] in a closed chamber containing tissue respiring in the dark. It is not necessary to integrate the expression but, if the integrated form is used, the resultant regression should not be constrained through the origin. This is important since any error in D will have significant effects on the estimation of the flux of electrons through the two pathways.

Managing identity transitions during radical change in nuclear engineering organizations

This study reports the construction and reconstruction of identities of new and existing employees during a significant transition phase of a nuclear engineering organization. We followed a group of new and existing employees over the period of three years, during which the organization constructed a greenfield nuclear facility with new generational technologies whilst in parallel, decommissioned the older reactor. This change led to the transfer and integration of existing trade-based employees with the newly recruited, primarily university educated graduates in the new site. Three waves of interview data were collected, in conjunction with the cognitive mapping of social grouping and photo elicitation portrayed the stories of different group of employees who either succeeded or failed at embracing their new professional identity. In contrast with the new recruits who constructed new identities as they join this organization, we identify and report on the number of enabling and disabling factors that influence the process of professional identity construction and reconstruction during gamma change.

Development and characterization of a novel, antimicrobial, sterile hydrogel dressing for burn wounds : single-step production with gamma irradiation creates silver nanoparticles and radical polymerization

Patients with burn wounds are susceptible to wound infection and sepsis. This research introduces a novel burn wound dressing that contains silver nanoparticles (SNPs) to treat infection in a 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na(+) ) hydrogel. Silver nitrate was dissolved in AMPS-Na(+) solution and then exposed to gamma irradiation to form SNP-infused hydrogels. The gamma irradiation results in a cross-linked polymeric network of sterile hydrogel dressing and a reduction of silver ions to form SNPs infused in the hydrogel in a one-step process. About 80% of the total silver was released from the hydrogels after 72 h immersion in simulated body fluid solution; therefore, they could be used on wounds for up to 3 days. All the hydrogels were found to be nontoxic to normal human dermal fibroblast cells. The silver-loaded hydrogels had good inhibitory action against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus. Results from a pilot study on a porcine burn model showed that the 5-mM silver hydrogel was efficient at preventing bacterial colonization of wounds, and the results were comparable to the commercially available silver dressings (Acticoat(TM) , PolyMem Silver(®) ). These results support its use as a potential burn wound dressing.

Constitutive Regulation of the Firm: occupational health and safety, dismissal, discrimination and sexual harassment

As many other chapters in this book have noted, until recently labour lawyers have tended not to draaw on regulatory scholarship. In this chapter we look at certain areas of labour law through a particular kind of regulatory lens - regulation that requires firms to reconstitute their management processes and procedures, perhaps even their organisational cultures. In particular, we examine the kinds of regulatory demands made on firms by legal rules in four areas of labour law: (i) occupational health and safety (OHS)regulation; unfair dismissal law; equal opportunity (EO) and (iv) sexual harassment law.

Outcomes in gastric and junctional cancer using neoadjuvant and adjuvant chemotherapy (epirubicin, oxaliplatin, and capecitabine) and radical surgery

Background The MAGIC/UK Medical Research Council (MRC) trial set the standard of care for treatment of resectable gastric and junctional adenocarcinoma, demonstrating that perioperative chemotherapy with epirubicin, cisplatin and 5-fluorouracil (ECF) confers a survival benefit over surgery alone. The randomized ECF for advanced and locally advanced esophagogastric cancer (REAL-2) trial showed that, in the metastatic setting, the EOX regimen (epirubicin, oxaliplatin and capecitabine) is as effective as ECF, with a favourable toxicity profile. Methods Consecutive patients with resectable gastric or junctional adenocarcinoma treated with perioperative EOX, between 2007 and 2012, were retrospectively analysed. Results Fifty-nine patients (12 female, 47 male), commenced EOX therapy; 47 underwent surgery. A good pathological response was seen in 34 %, (16/47). Disease recurrence occurred in 19 patients (19/47, 40 %). Median overall survival was 22 months, with 4-year survival of 47 %. Chemotoxicities were consistent with those previously reported for this regimen. Conclusion This study in a high-volume centre demonstrates that EOX in resectable gastric and junctional adenocarcinoma is associated with a reasonable safety profile, and efficacy consistent with that reported for ECF.

Discrimination and mental health

The purpose of this study was to investigate the nature and prevalence of discrimination against people living with HIV/AIDS in West Bengal, India, and how discrimination is associated with depression, suicidal ideation and suicidal attempts. Semi-structured interviews and the Beck Depression Inventory were administered to 105 HIV infected persons recruited by incidental sampling, at an Integrated Counseling and Testing Center (ICTC) and through Networks of People Living with HIV/AIDS, in the West Bengal area. Findings showed that 40.8% of the sample has experienced discrimination at least in one social setting – such as family (29.1%), health centers (18.4%), community (17.5%) and workplace (6.8%). About two-fifths (40.8%) reported experiencing discrimination in multiple social settings. Demographic factors associated with discrimination were gender, age, occupation, education, and current residence. More than half of the sample was suffering from severe depression while 8.7% had attempted suicide. Discrimination in most areas was significantly associated with suicidal ideation and suicidal attempts. Prevalence of discrimination associated with HIV/AIDS is high in our sample from West Bengal. While discrimination was not associated with depressive symptomatology, discrimination was associated with suicidal ideation and attempts. These findings suggest that there is an urgent need for interventions to reduce discrimination of HIV/AIDS in the West Bengal region.

Porous versus porthole fuel injection in a radical farming scramjet: A numerical analysis

Numerically computed engine performance of a nominally two-dimensional radical farming scramjet with porous (permeable C/C ceramic) and porthole fuel injection is presented. Inflow conditions with Mach number, stagnation pressure, and enthalpy of 6.44, 40.2MPa, and 4.31 MJ/kg respectively, and fuel/air equivalence ratio of 0.44 were maintained, along with engine geometry. Hydrogen fuel was injected at an axial location of 92.33mm downstream of the leading edge for each investigated injection method. Results from this study show that porous fuel injection results in enhanced mixing and combustion compared to porthole fuel injection. This is particularly evident within the first half of the combustion chamber where porous fuel injection resulted in mixing and combustion efficiencies of 76% and 63% respectively. At the same location, porthole fuel injection resulted in efficiencies respectively of 58% and 46%. Key mechanisms contributing to the observed improved performance were the formation of an attached oblique fuel injection shock and associated stronger shock-expansion train ingested by the engine, enhanced spreading of the fuel in all directions and a more rapidly growing mixing layer.

Using upper bounds on attainable discrimination to select discrete valued features

Selection of features that will permit accurate pattern classification is a difficult task. However, if a particular data set is represented by discrete valued features, it becomes possible to determine empirically the contribution that each feature makes to the discrimination between classes. This paper extends the discrimination bound method so that both the maximum and average discrimination expected on unseen test data can be estimated. These estimation techniques are the basis of a backwards elimination algorithm that can be use to rank features in order of their discriminative power. Two problems are used to demonstrate this feature selection process: classification of the Mushroom Database, and a real-world, pregnancy related medical risk prediction task - assessment of risk of perinatal death.

Feature selection using expected attainable discrimination

We propose expected attainable discrimination (EAD) as a measure to select discrete valued features for reliable discrimination between two classes of data. EAD is an average of the area under the ROC curves obtained when a simple histogram probability density model is trained and tested on many random partitions of a data set. EAD can be incorporated into various stepwise search methods to determine promising subsets of features, particularly when misclassification costs are difficult or impossible to specify. Experimental application to the problem of risk prediction in pregnancy is described.