The male germ unit of Rhododendron : quantitative cytology, three-dimensional reconstruction, isolation and detection using fluorescent probes

The sperm cells of Rhododendron laetum and R. macgregoriae differentiate within the pollen tube about 24 h after germination in vitro. Threedimensional reconstruction shows that the sperm cells are paired together, and both have extensions that link with the tube nucleus, forming a male germ unit. Quantitative analysis shows that the sperm cells in each pair differ significantly in surface area, but not in cell volume nor in numbers of mitochondria or plastids. When isolated from pollen tubes by osmotic shock, the sperm cells became ellipsoidal and surrounded by their own plasma membrane, while a proportion remained in pairs linked by the inner tube plasma membrane. Both generative and sperm cells are visualized in pollen tube preparations by immunofluorescence with anti-tubulin and anti-actin monoclonal antibodies (MAbs) combined with H33258 fluorescence of the nuclei. Video-image processing shows the presence of an axial microtubule cage in the generative cells, and some microtubules are present in the cytoplasmic extensions that clasp the tube nucleus. Following sperm cell division, the extensive phragmoplast between the sperm nuclei is partitioned by the plasma membranes.

Assessment of variation in the alberta context tool : the contribution of unit level contextual factors and practice specialty in Canadian pediatric acute care settings

Background: There are few validated measures of organizational context and none that we located are parsimonious and address modifiable characteristics of context. The Alberta Context Tool (ACT) was developed to meet this need. The instrument assesses 8 dimensions of context, which comprise 10 concepts. The purpose of this paper is to report evidence to further the validity argument for ACT. The specific objectives of this paper are to: (1) examine the extent to which the 10 ACT concepts discriminate between patient care units and (2) identify variables that significantly contribute to between-unit variation for each of the 10 concepts.

Methods: 859 professional nurses (844 valid responses) working in medical, surgical and critical care units of 8 Canadian pediatric hospitals completed the ACT. A random intercept, fixed effects hierarchical linear modeling (HLM) strategy was used to quantify and explain variance in the 10 ACT concepts to establish the ACT’s ability to discriminate between units. We ran 40 models (a series of 4 models for each of the 10 concepts) in which we systematically assessed the unique contribution (i.e., error variance reduction) of different variables to between-unit variation. First, we constructed a null model in which we quantified the variance overall, in each of the concepts. Then we controlled for the contribution of individual level variables (Model 1). In Model 2, we assessed the contribution of practice specialty (medical, surgical, critical care) to variation since it was central to construction of the sampling frame for the study. Finally, we assessed the contribution of additional unit level variables (Model 3).

Results: The null model (unadjusted baseline HLM model) established that there was significant variation between units in each of the 10 ACT concepts (i.e., discrimination between units). When we controlled for individual characteristics, significant variation in the 10 concepts remained. Assessment of the contribution of specialty to between-unit variation enabled us to explain more variance (1.19% to 16.73%) in 6 of the 10 ACT concepts. Finally, when we assessed the unique contribution of the unit level variables available to us, we were able to explain additional variance (15.91% to 73.25%) in 7 of the 10 ACT concepts.

Conclusion: The findings reported here represent the third published argument for validity of the ACT and adds to the evidence supporting its use to discriminate patient care units by all 10 contextual factors. We found evidence of relationships between a variety of individual and unit-level variables that explained much of this between-unit variation for each of the 10 ACT concepts. Future research will include examination of the relationships between the ACT’s contextual factors and research utilization by nurses and ultimately the relationships between context, research utilization, and outcomes for patients.

Working collaboratively in a group assignment using a Mediawiki for an architecture and construction management undergraduate unit

This paper describes an architecture and construction management unit which implements Mediawiki in teaching and learning. The main objective of using the Mediawiki is to engage students to work collaboratively online in a group assignment. It also aims to further develop student information technology skills and thus enhance their learning experience. One of the learning objectives of the unit is to develop the ability to communicate the results of student research in construction technology using appropriate digital media from which Mediawiki was chosen. This paper outlines the challenges and issues faced in the implementation of Mediawiki as a collaborative tool in a group assignment of an architecture and construction management unit. It also discusses how academic staff and students were supported through the process of learning to use the Mediawiki. Finally, potential future directions of using Mediawiki in teaching and learning are explored based on students’ comments and feedback.

A nonlinear approach to testing the unit root null hypothesis : an application to international health expenditures

In this article, we examine the unit root null hypothesis for per capita total Health Expenditures (HEs), per capita private HEs and per capita public HEs for 29 Organization for Economic Co-operation and Development (OECD) countries. The novelty of our work is that we use a new nonlinear unit root test that allows for one structural break in the data series. We find that for around 45% of the countries, we are able to reject the unit root hypothesis for each of the three HE series. Moreover, using Monte Carlo simulations, we show that our proposed unit root model has better size and power properties than the widely used Augmented Dickey–Fuller (ADF) and Lagrange Multiplier (LM) type tests.

Vascular access surveillance : the role of the access nurse in the renal dialysis unit.

Introduction
In January 2006, the Renal Dialysis Unit at Geelong Hospital appointed a Vascular Access Nurse. A Transonic Flow Qc HDO2 Ultrasound Dilution Monitor was purchased to monitor access flow and recirculation in arteriovenous fistulae in an attempt to predict AVF stenoses requiring early surgical correction.

Methods
A bi-monthly monitoring program tested all facility-based patients. 82 patients were assessed for access flow and recirculation between February and December 2006.

Results
18 (22%) had poor AVF function; 13 with access flows <500ml/minute on initial testing and 5 with an access flow decreasing >25% over a four month period. Of the 18 patients shown to have poor access flow, 2 died within one month of measurement while 5 were too frail to attempt corrective surgery. The remaining 11 proceeded to ultrasound or fistulography. A >50% stenosis was detected in all 11 cases. Of these, 4 had successful vein patch surgery and one had PTFE grafting, each with marked improvement in access flow. One had failed vein patch surgery requiring creation of a femoral AVF, one patient required cvc insertion to await AVF creation, and one had failed stenting requiring a permanent cvc. 3 died before planned surgery.

Conclusion
5 of the 82 patients that had access flow assessment, and needed further evaluation, proceeded to successful pre-emptive surgical intervention. We believe the Transonic is a useful adjunct to routine clinical AVF surveillance, in providing early evidence of AVF failure that can be avoided by pre-emptive surgery.

Creating value in an introductory business IS and IT unit

Given the downturn in student enrolments in Information Systems (IS) and Information Technology (IT) units, and the poor performance of a first-year IS and IT common-core unit in a business school, a new unit was developed. Action and design science research methods were employed. The new unit has a unique focus on two key skills and on modern IT and information literacy. The first skill involves describing information systems, and the second, determining how to create business value with IT in specific business contexts. Modern IT tools like a Web-based productivity suite and professional networking services are introduced, together with advanced search techniques and services and an information quality evaluation framework. The evaluation of the utility and efficacy of the unit is based on the institutional standard student feedback survey and unsolicited feedback. The unit has achieved a significant improvement in evaluation results and feedback from students, as well as converting students who were previously averse to IS and IT to study further in these areas.

Predicting the acceptance of unit guide information systems

Information Systems can play an important role in ensuring and improving the quality of education provided. However, lack of acceptance of these information systems and resistance of technology innovations by the end users limit the expected benefits of the system. This research attempts to identify the key determinants for the acceptance of the Unit Guide Information Systems (UGIS) in the Australian higher education sector. The technology acceptance model (TAM), social cognitive theory (SCT) and model of PC utilization (MPCU) are combined to provide a new framework for this analysis. Results of the study are consistent with the technology acceptance factors for explaining the behavioural intention of the academics. The study also shows the effects of application specific self-efficacy, application specific anxiety and social influence on the acceptance of UGIS. Implications of the results are discussed within the context of unit guides and curriculum mapping.

Estimating non-response bias in a web-based survey of technology acceptance : a case study of unit guide information systems

Surveys are mostly challenged by response rates. Among the various types of survey research, web-based (internet-based/electronic/online) surveys are commonly used for data collection for a geographically diverse population. In surveys with high/low response rates, non-response bias can be a major concern. While it is not always possible to measure the actual bias due to non-response there are different approaches and techniques that help to identify reasons of non-response bias. The aims of this paper are twofold. (1) To provide an appropriate, interesting and important non-response bias case study for future web-based surveys that will provide guidance to other Information Systems researchers. The case-study concerns an online-survey to evaluate a technology acceptance model for Unit Guide Information systems (UGIS). (2) To discuss how nonresponse bias in a web-based technology acceptance study of an information system (UGIS in this case) can be contained and managed.

A cascade genetic algorithm and particle swarm approach for solving unit commitment and economic dispatch problems

Positive Unit commitment and economic dispatch are two important decisions in thermal power generation scheduling. The tasks involve determination and allocation of power generation to thermal units that minimize the total power generation cost and satisfy the production constraints.This paper presents a cascade Genetic Algorithm and Particle Swarm Optimization (GA-PSO) approach for solving thermal power generation scheduling based on a layered matrix encoding structure.The proposed hybrid method is compared to layered matrix encoding GA using the thermal power generation problem given in Williams [1] to demonstrate its effectiveness in generating an optimal, cost-effective power generation schedule.The results showed that cascade GA-PSO outperformed the layered matrix encoding GA in minimizing the total power production cost for unit commitment and power dispatch problems.

Comparing the small sample properties of two break Lagrange Multiplier unit root tests

In this note, we examine the size and power properties and the break date estimation accuracy of the Lee and Strazicich (LS, 2003) two break endogenous unit root test, based on two different break date selection methods: minimising the test statistic and minimising the sum of squared residuals (SSR). Our results show that the performance of both Models A and C of the LS test are superior when one uses the minimising SSR procedure.

Early diagnosis and treatment of necrotizing fasciitis can improve survival : an observational intensive care unit cohort study

Background
The aim of this study was to describe the clinical characteristics, causative pathogens, clinical management and outcomes of patients presenting to a tertiary adult Australian intensive care unit (ICU) with a diagnosis of necrotizing fasciitis (NF).
Methods
This retrospective observational study was conducted in a 19-bed, level III, adult ICU in a 450-bed tertiary, regional hospital. Clinical databases were accessed for patients diagnosed with NF and admitted to The Geelong Hospital ICU between 1 February 2000 and 1 June 2011. Information on severity of sepsis, surgical procedures and microbiological results were collected.
Results
Twenty patients with NF were identified. The median age was 52.5 years and 38% were female. The overall mortality rate was 8.3%. Common co-morbidities were diabetes (21%) and heart failure (17%), although 50% of patients had no co-morbidities. Group A Streptococcus was the identified pathogen in 11 (46%) patients, and Streptococcus milleri group in 5 (21%) patients. Hyperbaric oxygen therapy was not used in the majority of patients. The initial antibiotics administered were active against subsequently cultured bacteria in 83% of patients. Median time to surgical debridement was 20 h. Diagnosis and management was delayed in the nosocomial group.
Conclusions
This study reports physiological data, aetiology and therapeutic interventions in NF for an adult tertiary hospital. We demonstrate one of the lowest reported mortality rates, with early surgical debridement being achieved in the majority of patients. The main delay was found to be in the diagnosis of NF.