bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a real‐time multiplex PCR system for the quantitative detection of Chinese GM rice
Authors: Gu Shao‐bin , Wu Ying , Li Shi‐Chang , Li Li , Yang Jian‐bo
Published: March 2009

BACKGROUND: Rice is one of the most important staple food crops for more than half the global population, who rely on it for as much as 80% of their diet. By one estimate, the world population is projected to grow to approximately 11 billion people by the year 2050. So it is a formidable task to meet the future demand. For this reason, breeders make a great deal of effort to produce new rice varieties with traits such as higher yield, improved nutritional content and better resistance to disease and pests, via transgenic biotechnological protocols. Dozens of transgenic rice lines have been developed since the first transgenic rice plant production in the late 1980s. With the rapid approach of transgenic rice commercialisation, it is becoming necessary to develop techniques capable of detecting and quantifying genetically modified (GM) rice.

RESULT: Here we describe a method in which transgenic DNA is quantified by amplifying part of the 35S‐CaMV promoter and standardising it against an amplified portion of an endogenous single copy, rice specific gene encoding sucrose phosphate synthase. Both reactions are performed simultaneously in a single tube. Standard calibration curves were developed by diluting DNA extracted from a blend of non‐transgenic (c.v., Nipponbare) and 5% KMD2 transgenic rice. The method was tested for the quantification of the five GM rice events, including KMD2, Wan 21A, GC‐1, H1597 and TR4, which contain the 35S‐CaMV promoter. The coefficient of variation varied from 3.15% to 12.84%, which is up to acceptance criterion over the dynamic range of the method.

CONCLUSION: In this study, we successfully applied a multiplex real‐time PCR assay to GM rice, which employed SPS as the endogenous reference gene and the gene regulation element 35S‐CaMV promoter as a GMO marker. The detection limit and limit of quantification is sufficient to comply with all relevant regulations in the EU and worldwide. The detection system could be applied in routine analysis for the quantification of GM rice in food materials, such as instant rice, unpolished rice, rice flours, biscuit powders, and starch. It may prove useful with regard to a robust screening technique of broad utility as transgenic rice enters global commodity markets. Copyright © 2009 Society of Chemical Industry
Estimating potential evapotranspiration from limited weather data over Gangetic West Bengal, India: a neurocomputing approach
Authors: Chattopadhyay Surajit , Jain Rajni , Chattopadhyay Goutami
Published: March 2009

This paper reports the development of a neurocomputing‐based model for estimating the potential evapotranspiration over Gangetic West Bengal, India during the summer monsoon months of June, July and August. An artificial neural network is implemented in the form of multilayer perceptron to generate the model. Three weather variables, surface temperature, vapour pressure and rainfall are used as the independent variables in generating the model. The performance of the model is judged statistically against non‐linear regression in the form of asymptotic regression. The study reveals that an artificial neural network is more efficient than the regression approach to estimate the potential evapotranspiration in the summer monsoon months. Furthermore, it is established that the artificial neural network and non‐linear regression have almost equal efficiency in the previously mentioned estimation in the month of June. However, in July and August the higher values of correlation and Willmott's indices, and lower values of estimation error, indicate that the artificial neural network is more reliable than the non‐linear regression approach. Since evapotranspiration is one of the basic components of the hydrological cycle and is essential for estimating irrigation water requirement, an efficient estimation procedure may help in agrometeorological modelling and irrigation scheduling in the summer monsoon months, which are of high importance for agriculture in the study zone. Copyright © 2009 Royal Meteorological Society
Synthesis and characterization of a novel electrochromic aromatic polyamide from AB‐type triphenylamine‐based monomer
Authors: Liou Guey‐Sheng , Lin Kai‐Han
Published: March 2009

A new triphenylamine‐based polyamide I was prepared by direct polycondensation of AB‐type monomer, 4‐amino‐4′‐carboxy‐4″‐methoxytriphenylamine (4), in the presence of triphenyl phosphite and pyridine as condensation agents. The obtained polyamide I showed excellent solubility in aprotic polar solvents such as NMP, DMAc, DMF, and DMSO and could be cast into transparent film with weight‐average molecular weight (Mw = 63,400) and polydispersity index (PDI = 1.79). The polyamide I exhibited good thermal stability with relatively high glass‐transition temperature (282 °C), 10% weight‐loss temperature above 470 °C under a nitrogen atmosphere, and char yield at 800 °C in nitrogen higher than 64%. It also showed maximum ultraviolet‐visible absorption at 362 nm and exhibited fluorescence emission maxima at 493 nm in NMP solution with fluorescence quantum yield 4.4%. Cyclic voltammogram of polyamide I film cast onto an indium tin oxide coated glass substrate exhibited one oxidative redox couple at 0.72 V (oxidation onset potential) versus Ag/AgCl in acetonitrile solution and revealed good stability of the electrochromic characteristic with a color change from colorless to green at applied potentials ranging from 0.00 to 1.10 V. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 1988–2001, 2009
Star‐shaped polypeptide/glycopolymer biohybrids: Synthesis, self‐assembly, biomolecular recognition, and controlled drug release behavior
Authors: Qiu Shuo , Huang Hui , Dai Xiao‐Hui , Zhou Wei , Dong Chang‐Ming
Published: March 2009

Star‐shaped polypeptide/glycopolymer biohybrids composed of poly(γ‐ benzyl L‐glutamate) and poly(D‐gluconamidoethyl methacrylate), exhibiting controlled molecular weights and low polydispersities, were synthesized by the combination of ring‐opening polymerization of γ‐benzyl‐L‐glutamate N‐carboxyanhydride and the direct atom transfer radical polymerization of unprotected D‐gluconamidoethyl methacrylate glycomonomer. These biohybrids were characterized in detail by means of FTIR, 1H NMR, gel permeation chromatography, differential scanning calorimetry, and wide angle X‐ray diffraction. Independent of weight fraction of hydrophilic glycopolymer segment, the biohybrids self‐assembled into large spherical micelles in aqueous solution, which had a helical polypeptide core surrounded by a multivalent glycopolymer shell. The deprotected poly(L‐glutamate)/glycopolymer hybrid exhibited a pH‐sensitive self‐assembly behavior, and the average size of the nanoparticles decreased gradually over the aqueous pH value. Moreover, whatever these biohybrids existed in unimolecular level or glycopolymer‐surfaced nanoparticles, they had specific biomolecular recognition with Concanavalin A compared with bovine serum albumin. Furthermore, star‐shaped biohybrids showed a higher doxorubicin loading efficiency and longer drug‐release time than linear analogues. This potentially provides a platform for fabricating targeted anticancer drug delivery system and studying glycoprotein functions in vitro. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2009–2023, 2009
1,4‐Dilithio‐1,1,4,4‐tetraphenylbutane in diethyl ether: An effective initiator for the living anionic polymerization of dienes
Authors: Dimitrov Philip , Iyer Pradeep , Van Beylen Marcel , Hogen‐Esch Thieo E.
Published: March 2009

The anionic polymerization of butadiene initiated with 1,4‐dilithio‐1,1,4,4‐tetraphenylbutane (LiTPB) in diethyl ether (DEE) gives polybutadiene (PBD) with high 1,2 content (>70%), narrow polydispersities (1.04 < Mw/Mn < 1.20), and predicted molecular weights. In THF, this polymerization does not work very well. After removal of DEE and addition of THF, the PBD dianion is end capped quantitatively by addition of 1,1‐diphenylethylene (DPE) to give the diphenylalkyl end capped PBD dianion. Subsequent addition of methyl methacrylate at low temperatures results in the formation of well‐defined PMMA‐b‐PBD‐b‐PMMA triblock copolymers. The results are accounted for by taking into account the effects of Li ion solvation on the BD initiation and end capping of the PBD anion by DPE. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2198–2206, 2009
Hardware implementation of fault‐tolerance in dual computer systems
Authors: Samet Refik
Published: March 2009

In this paper, we propose an architectural design for a dual computer system (DCS) that operates in real‐time with the fault‐tolerance implemented purely by hardware. We have a novel design allowing the implementation of hardware that performs the following key services: the determination of fault type (temporary or permanent) and the localization of the faulty computer without using self‐testing techniques and diagnosis routines. We also propose a non‐trivial sequence of services for fault‐tolerance in which the determination of the fault type and the recovery of computational processes after a temporary fault are realized before fault localization. Our design has several benefits: the designed hardware shortens the recovery point time period; the proposed non‐trivial sequence of fault‐tolerant services reduces (to two) the number of logical segments that should be re‐run to recover the computational processes; and the determination of the fault type allows eliminating only the computer with a permanent fault. These contributions bring both an increase in system performance and an increase in the degree of system reliability. Copyright © 2009 John Wiley & Sons, Ltd.
Human Immunodeficiency Disease: How Should It Affect Surgical Decision Making?
Authors: Madiba T. E. , Muckart D. J. J. , Thomson S. R.
Published: March 2009

Background

The ever‐increasing prevalence of human immunodeficiency virus (HIV) infection and the continued improvement in clinical management has increased the likelihood of surgery being performed on patients with this infection. The aim of the review was to assess current literature on the influence of HIV status on surgical decision‐making.

Methods

A literature review was performed using MEDLINE articles addressing “human immunodeficiency virus,” “HIV,” “acquired immunodeficiency syndrome,” “AIDS,” “HIV and surgery.” We also manually searched relevant surgical journals and completed the bibliographic compilation by collecting cross references from published papers.

Results

Results of surgery between noninfected and HIV‐infected individuals and between HIV‐infected and acquired immunodeficiency syndrome (AIDS) patients are variable in terms of morbidity, mortality, and hospital stay. The risk of major surgery is not unlike that for other immunocompromised or malnourished patients. The multiple co‐morbidities associated with HIV infection and the availability of highly active antiretroviral therapy must be considered when assessing and optimizing the patient for surgery. The clinical stage of the patient’s disease should be evaluated with a focus on the overall organ system function. For patients with advanced HIV disease, palliative surgery offers relief of acute problems with improvement in the quality of life. When indicated, diagnostic surgery assists with further decision‐making in the medical management of these patients and hence should not be withheld.

Conclusion

HIV infection should not be considered a significant independent factor for major surgical procedures. Appropriate surgery should be offered as in normal surgical patients without fear of an unfavorable outcome.
Genetic diversity of the endangered Chinese endemic herb Saruma henryi Oliv. (Aristolochiaceae) and its implications for conservation
Authors: Zhou Tian‐Hua , Qian Zeng‐Qiang , Li Shan , Guo Zhi‐Gang , Huang Zhao‐Hui , Liu Zhan‐Lin , Zhao Gui‐Fang
Published: March 2009

Saruma henryi Oliv., the only representative of the monotypic genus Saruma Oliv. (Aristolochiaceae), is an endangered perennial herb endemic to China. It is a phylogenetically, ecologically, and medicinally important species. In the present study, inter‐simple sequence repeat (ISSR) markers were employed to investigate the genetic diversity and differentiation of 14 populations. A total of 16 selected primers yielded 175 bright and discernible bands, with an average of 10.94 per primer. POPGENE analysis showed that the genetic diversity was quite low at the population level (h = 0.0447–0.1243; I = 0.0642–0.1853; PPB = 10.29–36.57%), but pretty high at the species level (h = 0.2603; I = 0.3857; PPB = 73.71%). The hierarchical analysis of molecular variance (AMOVA) revealed a high level of genetic differentiation among populations (67.18% of total variance components, P < 0.001), in line with the gene differentiation coefficient (GST = 0.6903) and the limited among‐population gene flow (Nm = 0.2243). Both Principal Coordinates Analysis (PCoA) and UPGMA cluster analysis supported the grouping of all 14 populations into three geographic groups, among which there occurred a moderate level of genetic differentiation (33.18% of total variance components, P < 0.001) as shown by AMOVA analysis. In addition, Mantel test revealed a significant correlation between genetic and geographic distances among populations (r = 0.7792, P = 0.001), indicating the role of geographic isolation in shaping its present population genetic structure. The present levels and patterns of genetic diversity of S. henryi were assumed to result largely from its breeding system, geographic isolation, clonal growth, its unique biological traits and evolutionary history. The high genetic differentiation among populations implies that the conservation efforts should aim to preserve all the extant populations of this endangered herb.
Nonlinear acoustic–gravity waves
Authors: STENFLO L. , SHUKLA P. K.
Published: March 2009

Previous results on nonlinear acoustic–gravity waves are reconsidered. It turns out that the mathematical techniques used are somewhat similar to those already adopted by the plasma physics community. Consequently, a future interaction between physicists in different fields, e.g. in meteorology and plasma physics, can be very fruitful.
Why Sārus Cranes epitomize Karuṇarasa in the Rāmāyaṇa
Authors: HAMMER NIELS
Published: March 2009

By correlating literary evidence, avian ethology and neurophysiology I will try to demonstrate why Vālmīki chose a pair of Sārus Cranes, and not any other avian species, to epitomise grief and sorrow in the Rāmāyaṇa. This choice illustrates the importance of personal experience of the living reality (behaviour of Sārus Cranes); but the grief,śoka, as experienced by Vālmīki, became in later critical literature, therasaofkaruṇa, the aesthetic appreciation of grief, as suggested by Ānandavardhana and explained by Abhinavagupta. By emphasising the central importance of affective states (sthāyibhāvas) in life as well as in the arts (rasas) Vālmīki, Abhinavagupta and Ānandavardhana appear to have had a perception of the human condition that is consistent with recent developments in affective neuroscience; and thus it is the pitch and the tonal quality of the cries of grief that convey the depth and universality (sādhāraṇatva) of the emotion.
Khān al-Ẓāhir – bi-Ẓāhir al-Quds!
Authors: CYTRYN-SILVERMAN KATIA
Published: March 2009

In Jumādā II 661/April 1263 the Mamlūk sultan al-Ẓāhir Baybars visited Jerusalem and undertook various pious works, including the erection of a public khān for lodging those visiting the Holy City. Unfortunately Baybars's khān has not survived and much speculation has been made regarding its location. The Arabic sources relating to Baybars's deeds provide a good deal of information relating to his khān, which, once combined with western sources and archaeological evidence, allows us to suggest its probable site, its architectural type, and even range of services.
Foreword to ‘A Society for People’ by Peter Townsend
Authors: Sinfield Adrian
Published: March 2009

Peter Townsend reached 80 in April 2008. We thought it a particularly appropriate way to mark his outstanding contribution to the subjects of social policy and sociology by reprinting this essay published 50 years ago in the New Statesman. The title, ‘A Society for People’, identifies the dominant theme, not just for this paper, but for Peter's whole career.
Gender Equality and the European Employment Strategy: The Work/Family Balance Debate
Authors: León Margarita
Published: March 2009

This paper explores understandings of gender equality within the context of work/family balance strategies embedded in the European Employment Strategy (EES). The article compares developments in childcare provision with parental leave drawing the conclusion that while increasing childcare provision is a clear priority for the European Employment Strategy, parental leave and other measures aimed at balancing time spent on paid work and unpaid care are not given equal concern. Work/family balance strategies are primarily intended to facilitate the engagement of young mothers in the labour market by offering public childcare provision; this is done at the cost of not exploring other more far-reaching and complex understandings of the work/family conflict.
Politics of Recognition: What Can a Human Rights Perspective Contribute to Understanding Users' Experiences of Involvement in Mental Health Services?
Authors: Lewis Lydia
Published: March 2009

In the UK, participation in decision-making is increasingly being viewed as a right for users of mental health services. Yet research repeatedly finds a policy implementation gap in this area. Drawing on a localised, qualitative study involving three mental health service user/community groups, this article frames this issue in terms of a ‘politics of recognition’. It demonstrates how whilst government user involvement policies officially attempt to recognise users and their voices, they simultaneously reconstitute failures of recognition in terms of status subordination and a disqualified identity for service users, thereby obstructing participatory parity and amounting to a dereliction of the core principles underlying human rights.
Perceiving electrical stimulation of identified human visual areas
Authors: Murphey Dona K. , Maunsell John H. R. , Beauchamp Michael S. , Yoshor Daniel
Published: March 2009

We studied whether detectable percepts could be produced by electrical stimulation of intracranial electrodes placed over human visual areas identified with fMRI. Identification of areas was confirmed by recording local-field potentials from the electrode, such as face-selective electrical responses from electrodes over the fusiform face area (FFA). The probability of detecting electrical stimulation of a visual area varied with the position of the area in the visual cortical hierarchy. Stimulation of early visual areas including V1, V2, and V3 was almost always detected, whereas stimulation of late visual areas such as FFA was rarely detected. When percepts were elicited from late areas, subjects reported that they were simple shapes and colors, similar to the descriptions of percepts from early areas. There were no reports of elaborate percepts, such as faces, even in areas like FFA, where neurons have complex response properties. For sites eliciting percepts, the detection threshold was determined by varying the stimulation current as subjects performed a forced-choice detection task. Current thresholds were similar for late and early areas. The similarity between both percept quality and threshold across early and late areas suggests the presence of functional microcircuits that link electrical stimulation with perception.
Calmodulin kinase II is required for fight or flight sinoatrial node physiology
Authors: Wu Yuejin , Gao Zhan , Chen Biyi , Koval Olha M. , Singh Madhu V. , Guan Xiaoqun , Hund Thomas J. , Kutschke William , Sarma Satyam , Grumbach Isabella M. , Wehrens Xander H. T. , Mohler Peter J. , Song Long-Sheng , Anderson Mark E.
Published: March 2009

The best understood “fight or flight” mechanism for increasing heart rate (HR) involves activation of a cyclic nucleotide-gated ion channel (HCN4) by β-adrenergic receptor (βAR) agonist stimulation. HCN4 conducts an inward “pacemaker” current (If) that increases the sinoatrial nodal (SAN) cell membrane diastolic depolarization rate (DDR), leading to faster SAN action potential generation. Surprisingly, HCN4 knockout mice were recently shown to retain physiological HR increases with isoproterenol (ISO), suggesting that other If-independent pathways are critical to SAN fight or flight responses. The multifunctional Ca2+and calmodulin-dependent protein kinase II (CaMKII) is a downstream signal in the βAR pathway that activates Ca2+homeostatic proteins in ventricular myocardium. Mice with genetic, myocardial and SAN cell CaMKII inhibition have significantly slower HRs than controls during stress, leading us to hypothesize that CaMKII actions on SAN Ca2+homeostasis are critical for βAR agonist responses in SAN. Here we show that CaMKII mediates ISO HR increases by targeting SAN cell Ca2+homeostasis. CaMKII inhibition prevents ISO effects on SAN Ca2+uptake and release from intracellular sarcoplasmic reticulum (SR) stores that are necessary for increasing DDR. CaMKII inhibition has no effect on the ISO response in SAN cells when SR Ca2+release is disabled and CaMKII inhibition is only effective at slowing HRs during βAR stimulation. These studies show the tightly coupled, but previously unanticipated, relationship of CaMKII to the βAR pathway in fight or flight physiology and establish CaMKII as a critical signaling molecule for physiological HR responses to catecholamines.
Smoothing waves in array CGH tumor profiles
Authors: van de Wiel Mark A. , Brosens Rebecca , Eilers Paul H. C. , Kumps Candy , Meijer Gerrit A. , Menten Björn , Sistermans Erik , Speleman Frank , Timmerman Marieke E. , Ylstra Bauke
Published: March 2009

Motivation: Many high-resolution array comparative genomic hybridization tumor profiles contain a wave bias, which makes accurate detection of breakpoints in such profiles more difficult.

Results: An efficient and highly effective algorithm that largely removes the wave bias from tumor profiles by regressing the tumor profile data on data of profiles from the clinical genetics practice. Results are illustrated on two independent datasets. The algorithm is shown to be robust against the presence of true copy number aberrations. Moreover, the smoothed profiles are able to recapitulate the aberration location and signal for simulated tumor profiles.

Availability: Easy-to-use R scripts, user instructions and data are available from http://www.few.vu.nl/~mavdwiel/nowaves.html.

Contact:  mark.vdwiel@vumc.nl

Supplementary information:  Supplementary information are available at Bioinformatics online.
First report of Almond witches’ broom phytoplasma1 (‘Candidatus Phytoplasma phoenicium’) causing a severe disease on nectarine and peach trees in Lebanon
Authors: Abou‐Jawdah Y. , Sobh H. , Akkary M.
Published: March 2009

Symptoms of shoot proliferation characteristic of phytoplasma diseases were observed on nectarine (Prunus persica var. nucipersica) and peach (P. persica) trees in the Sarada plain, south of Lebanon. The presence of phytoplasmas in the two orchards visited was confirmed by nested polymerase chain reaction using universal primers. The amplified DNA fragments were cloned and sequenced. Blast analysis of over 1000 nucleotides demonstrated the presence of ‘Candidatus Phytoplasma phoenicium’ which is considered to be the causal agent of Almond witches’ broom. This phytoplasma which belongs to the pigeon pea witches’ broom group (16SrIX) can be devastating since Almond witches’ broom has killed thousands of almond trees in Lebanon and Iran. Previous reports indicated that Almond witches’ broom may be transmitted by grafting to peach and nectarine under experimental conditions. This is the first report of a natural and epidemic spread of ‘Ca. Phytoplasma phoenicium’ in peach and nectarine. Farmers in the region were advised to eradicate the infected trees immediately. Further studies on the epidemiology of ‘Ca. Phytoplasma phoenicium’ and its vector(s) are recommended in order to develop successful eradication or disease management programmes.
[FeFe]‐hydrogenase‐like gene is involved in the regulation of sensitivity to oxygen in yeast and nematode
Authors: Fujii Michihiko , Adachi Noritaka , Shikatani Kazuki , Ayusawa Dai
Published: March 2009

Oxygen is essential for the life of aerobic organisms, but reactive oxygen species (ROS) derived from oxygen can be a threat for it. Many genes are involved in generation of ROS, but not much attention has been focused on the reactions from which ROS are generated. We therefore screened for mutants that showed an increased sensitivity to oxidative stress in the nematode Caenorhabditis elegans, and isolated a novel mutant, oxy‐4(qa5001). This mutant showed an increased sensitivity to a high concentration of oxygen, and decreased longevity at 20 °C but not at 26 °C. The genetic analysis has revealed that oxy‐4 had a causative mutation in an [FeFe]‐hydrogenase‐like gene (Y54H5A.4). In the yeast Saccharomyces cerevisiae, a deletion of NAR1, a possible homologue of oxy‐4, also caused a similar increased sensitivity to oxygen. [FeFe]‐hydrogenases are enzymes that catalyze both the formation and the splitting of molecular hydrogen, and function in anaerobic respiration in anaerobes. In contrast, [FeFe]‐hydrogenase‐like genes identified in aerobic eukaryotes do not generate hydrogen, and its functional roles are less understood. Our results suggested that [FeFe]‐hydrogenase‐like genes were involved in the regulation of sensitivity to oxygen in S. cerevisiae and C. elegans.
Prognostic importance of epithelial–mesenchymal transition‐related protein expression in gastric carcinoma
Authors: Kim Min A , Lee Hye Seung , Lee Hee Eun , Kim Ji Hun , Yang Han‐Kwang , Kim Woo Ho
Published: March 2009

Aims:  Epithelial–mesenchymal transition (EMT) is defined as switching of polarized epithelial cells to a migratory fibroblastoid phenotype. EMT is known to be involved in the progression and metastasis of various cancers. The aim was to evaluate the expression of EMT‐related proteins in gastric carcinoma (GC).

Methods and results:  The expression of nine EMT‐related proteins in the GC tissues of 598 patients was evaluated by immunohistochemistry using a tissue array method. In addition, clinicopathological characteristics and survival were compared with the expression of EMT‐related proteins. Loss of epithelial protein and/or acquisition of the expression of mesenchymal proteins were observed in GC. These protein alterations were associated with diffuse type histology, advanced stage and poor patient outcome, respectively. Subjects were divided into three groups according to degree of EMT‐related protein alteration. Increases in alteration of EMT‐related protein were found to be significantly associated with poorly differentiated histology, higher pTNM stage and unfavourable outcome. Multivariate analysis showed that alterations in the expression of EMT‐related proteins were independently associated with poor prognosis.

Conclusions:  Loss of epithelial proteins and/or the acquisition of mesenchymal proteins are associated with poorly differentiated histology, advanced stage and poor outcome in GC. The awareness and inhibition of EMT offer a promising target for prevention of metastatic progression and invasion.
Career trajectories of nurses leaving the hospital sector in Ontario, Canada (1993–2004)
Authors: Alameddine Mohamad , Baumann Andrea , Laporte Audrey , O’Brien‐Pallas Linda , Levinton Carey , Onate Kanecy , Deber Raisa
Published: March 2009

Title. Career trajectories of nurses leaving the hospital sector in Ontario, Canada (1993–2004).

Aim. This paper is a report of an analysis of the career trajectories of nurses 1 year after leaving hospitals.

Background. Although hospitals are traditionally the largest employers of nurses, technological advances and budgetary constraints have resulted in many countries in relative shrinkage of the hospital sector and a shift of care (and jobs) into home/community settings. It has been often assumed that nurses displaced from hospitals will move to work in the other workplaces, especially the community sector.

Method. Employment patterns were tracked by examining a longitudinal database of all 201,463 nurses registered with the College of Nurses Ontario (Canada) between 1993 and 2004. Focusing on the employment categories Active (Working in nursing), Eligible‐Seeking nursing employment or Dropout from the nursing labour market, year‐to‐year transition matrixes were generated by sector and sub‐sector of employment, nurse type, age group and work status.

Findings. For every nurse practising nursing in any non‐hospital job or in the community a year after leaving hospitals, an average of 1·3 and four nurses, respectively, dropped out of Ontario’s labour market. The proportion of nurses leaving hospitals transitioning to the Dropout category ranged from 63·3% (1994–95) to 38·6% (2001–02). The proportion dropping out of Ontario’s market was higher for Registered Practical Nurses (compared to Registered Nurses), increased with age and decreased with degree of casualization in nurses’ jobs.

Conclusion. Downsizing hospitals without attention to the potentially negative impact on the nursing workforce can lead to retention difficulties and adversely affects the overall supply of nurses.
Climate change and evolution of the New World pitviper genus Agkistrodon (Viperidae)
Authors: Douglas Michael E. , Douglas Marlis R. , Schuett Gordon W. , Porras Louis W.
Published: March 2009

Aim  We derived phylogenies, phylogeographies, and population demographies for two North American pitvipers, Agkistrodon contortrix (Linnaeus, 1766) and A. piscivorus (Lacépède, 1789) (Viperidae: Crotalinae), as a mechanism to evaluate the impact of rapid climatic change on these taxa.

Location  Midwestern and eastern North America.

Methods  We reconstructed maximum parsimony (MP) and maximum likelihood (ML) relationships based on 846 base pairs of mitochondrial DNA (mtDNA) ATPase 8 and ATPase 6 genes sequenced over 178 individuals. We quantified range expansions, demographic histories, divergence dates and potential size differences among clades since their last period of rapid expansion. We used the Shimodaira–Hasegawa (SH) test to compare our ML tree against three biogeographical hypotheses.

Results  A significant SH test supported diversification of A. contortrix from northeastern Mexico into midwestern–eastern North America, where its trajectory was sundered by two vicariant events. The first (c. 5.1 Ma) segregated clades at 3.1% sequence divergence (SD) along a continental east–west moisture gradient. The second (c. 1.4 Ma) segregated clades at 2.4% SD along the Mississippi River, coincident with the formation of the modern Ohio River as a major meltwater tributary. A single glacial refugium was detected within the Apalachicola region of southeastern North America. Significant support was also found for a hypothesis of trans‐Gulf rafting by the common ancestor of A. piscivorus from eastern Mexico (possibly the Yucatan Peninsula) to northern Florida. There, a Mid–Late Pliocene marine transgression separated it at 4.8% SD from mainland North America. Significant range expansions followed compressive glacial effects in three (of four) A. contortrix clades and in two (of three) A. piscivorus clades, with the Florida A. piscivorus clade exhibiting significant distributional stasis.

Main conclusions  Pliocene glaciations, rapidly developing western aridity, and Pleistocene glacial meltwaters seemingly led to the diversification of A. contortrix and A. piscivorus in North America. Both species were pushed southwards by Pleistocene climate change, with subsequent northward expansions uninhibited topographically. The subspecific taxonomy used for A. contortrix and A. piscivorus today, however, appear non‐representative. The monophyletic Florida subspecies of A. piscivorus may be a distinct species (at 4.8% SD), whereas two western subspecies of A. contortrix also appear to constitute a single distinct species, pending additional analyses. We conclude that both species of Agkistrodon can be used as suitable ectothermic models to gauge impacts of future climate change.
A history and review of school meal standards in the UK
Authors: Evans C. E. L. , Harper C. E.
Published: March 2009

This review details the history of school meals in the UK, from their origin in the mid‐19th Century, to the present day, and provides a summary of how each country has independently developed its own food and or nutrient‐based standards for school meals. The standards in place in the UK are amongst some of the most detailed and comprehensive in the world. Regular monitoring to ensure that these standards are being met and that schools are improving healthy eating is essential to their success. Of no lesser importance are assessments to determine whether changes to school meals are having an impact on the diets of school children. It is early days in terms of evaluation because food‐based standards have only recently been introduced and nutrient‐based standards are in the process of being developed and implemented. Studies in England provide some evidence that the re‐introduction of standards for school food is having a positive impact on both pupil’s food choices and the nutritional profile of school lunches. At present, there does not appear to be a pattern between current obesity levels and the types of school meals provided, although it is anticipated that, in the long term, these comprehensive standards may contribute to a less obesogenic environment.
Contribution of thickened drinks, food and enteral and parenteral fluids to fluid intake in hospitalised patients with dysphagia
Authors: Vivanti A. P. , Campbell K. L. , Suter M. S. , Hannan‐Jones M. T. , Hulcombe J. A.
Published: March 2009

Background:  Studies amongst older people with acute dysphagic stroke requiring thickened fluids have assessed fluid intakes from combinations of beverage, food, enteral and parenteral sources, but not all sources simultaneously. The present study aimed to comprehensively assess total water intake from food, beverages, enteral and parenteral sources amongst dysphagic adult in‐patients receiving thickened fluids.

Methods:  Patients requiring thickened fluid following dysphagia diagnosis were recruited consecutively from a tertiary teaching hospital’s medical and neurosurgical wards. Fluid intake from food and beverages was assessed by wastage, direct observation and quantified from enteral and parenteral sources through clinical medical records.

Results:  No patients achieved their calculated fluid requirements unless enteral or parenteral fluids were received. The mean daily fluid intake from food was greater than from beverages whether receiving diet alone (food: 807 ± 363 mL, food and beverages: 370 ± 179 mL; P < 0.001) or diet with enteral or parenteral fluid support (food: 455 ± 408 mL, food and beverages: 263 ± 232 mL; P < 0.001). Greater daily fluid intakes occurred when receiving enteral and parenteral fluid in addition to oral dietary intake, irrespective of age group, whether assistance was required, diagnosis and whether stage 3 or stage 2 thickened fluids were required (P < 0.05). After enteral and parenteral sources, food provided the most important contribution to daily fluid intakes.

Conclusions:  The greatest contribution to oral fluid intake was from food, not beverages. Designing menus and food services that promote and encourage the enjoyment of fluid dense foods, in contrast to thickened beverages, may present an important way to improve fluid intakes of those with dysphagia. Supplemental enteral or parenteral fluid may be necessary to achieve minimum calculated fluid requirements.
Psychosocial factors underlying the mother’s decision to continue exclusive breastfeeding for 6 months: an elicitation study
Authors: Bai Y. K. , Middlestadt S. E. , Joanne Peng C.‐Y. , Fly A. D.
Published: March 2009

Background:  Despite numerous benefits of exclusive breastfeeding (EBF) for infants and mothers, a significant decrease in the EBF rate in the USA at six months compared to the rate at birth suggests that reasons for initiation and continuation of EBF may differ. The purpose of this qualitative study was to explore psychosocial factors underlying the continued EBF behaviour for six months, in order to identify salient belief structures according to the theory of planned behaviour.

Methods:  Participants were recruited from central Indiana in the USA. They were asked to respond to an open‐ended questionnaire designed to elicit positive/negative consequences, approving/disapproving social referents, and easy/difficult circumstances in continuing EBF for six months. Responses were translated into behavioural, normative, and control beliefs of the theory.

Results:  Findings suggest that respondents (1) value emotional and health benefits of continued EBF for six months; (2) feel the approval from family and friends but disapproval from the society; (3) view health professional’s position as positive and negative.

Conclusions:  Breastfeeding educators can more likely improve the EBF duration by addressing these salient beliefs. Identified beliefs provide a basis for the development of a quantitative instrument to further study the EBF behaviour.
Gene flow of Acanthaster planci (L.) in relation to ocean currents revealed by microsatellite analysis
Authors: YASUDA NINA , NAGAI SATOSHI , HAMAGUCHI MASAMI , OKAJI KEN , GÉRARD KARIN , NADAOKA KAZUO
Published: March 2009

Population outbreaks of the coral‐eating starfish, Acanthaster planci, are hypothesized to spread to many localities in the Indo‐Pacific Ocean through dispersal of planktonic larvae. To elucidate the gene flow of A. planci across the Indo‐Pacific in relation to ocean currents and to test the larval dispersal hypothesis, the genetic structure among 23 samples over the Indo‐Pacific was analysed using seven highly polymorphic microsatellite loci. The F‐statistics and genetic admixture analysis detected genetically distinct groups in accordance with ocean current systems, that is, the Southeast African group (Kenya and Mayotte), the Northwestern Pacific group (the Philippines and Japan), Palau, the North Central Pacific group (Majuro and Pohnpei), the Great Barrier Reef, Fiji, and French Polynesia, with a large genetic break between the Indian and Pacific Oceans. A pattern of significant isolation by distance was observed among all samples (P = 0.001, r = 0.88, n = 253, Mantel test), indicating restricted gene flow among the samples in accordance with geographical distances. The data also indicated strong gene flow within the Southeast African, Northwestern Pacific, and Great Barrier Reef groups. These results suggest that the western boundary currents have strong influence on gene flow of this species and may trigger secondary outbreaks.
Explaining educational inequalities in birthweight: the Generation R Study
Authors: Jansen Pauline W. , Tiemeier Henning , Looman Caspar W. N. , Jaddoe Vincent W. V. , Hofman Albert , Moll Henriëtte A. , Steegers Eric A. P. , Verhulst Frank C. , Mackenbach Johan P. , Raat Hein
Published: March 2009

Although low socio‐economic status has consistently been associated with lower birthweight, little is known about the factors whereby socio‐economic disadvantage influences birthweight. We therefore examined explanatory mechanisms that may underlie the association between the educational level of pregnant women, as an indicator of socio‐economic status, and birthweight. The study was embedded within a population‐based cohort study in the Netherlands. Information on maternal education, offspring's birthweight and several determinants of birthweight was available for 3546 pregnant women of Dutch origin.

Infants of the lowest educated women had a statistically significantly lower birthweight than infants of the highest educated women [difference adjusted for gender and gestational age: −123 g (95% CI −167, –79)]. Parity, age of the pregnant women, hypertension, parental height and parental birthweight, marital status, pregnancy planning, financial concerns, number of people in household, weight gain and smoking habits individually explained part of the differences in birthweight, while adjustment for working hours and body mass index resulted in increases in birthweight differences between the educational levels. After full adjustment, the difference in birthweight between lowest and highest education was reduced by 66%. Our study confirmed remarkable educational inequalities in birthweight, a large part of which was explained by pregnancy characteristics, anthropometrics, the psychosocial and material situation, and lifestyle‐related factors. Altering smoking habits may be an option to reduce educational differences in birthweight, as many lower‐educated women tend to continue smoking during pregnancy. In order to tackle inequalities in birthweight, it is important that interventions are accessible for pregnant women in lower socio‐economic strata.
Modelling the association of blood pressure during pregnancy with gestational age and body mass index
Authors: Thompson Mary Lou , Williams Michelle A. , Miller Raymond S.
Published: March 2009

Improved understanding of the determinants of blood pressure (BP) changes during pregnancy is essential for decreasing the morbidity and mortality borne by women and their families worldwide. While most epidemiological studies consider associations based on categorical risk factor classifications, using measurements on a continuous scale has been advocated as a means of gaining richer insights into biological processes. We modelled the relationship during pregnancy of continuous systolic (S) and diastolic (D) BP distributions with gestational age and pre‐pregnancy body mass index (BMI) using fractional polynomials. We used information, including antenatal BP values abstracted from medical records, from a prospective cohort of 1733 women recruited before 20 weeks' gestation.

The percentiles for SBP and DBP changed over pregnancy, with DBP percentiles decreasing initially, followed by an increase starting about mid‐second trimester. Modelling the joint impact of BMI and gestational age on mean BP indicated an increase in mean BP with increasing BMI that was attenuated at higher BMI levels, later in pregnancy. This attenuation persisted in a variety of sub‐analyses which explored the possibility that it was caused by confounding or by influential groupings of subjects. Estimated longitudinal percentiles that characterise the BP distribution across gestation may facilitate evaluation of BP during pregnancy. BP patterns observed over pregnancy and, in particular, the attenuation of BP increases at high BMI, late in pregnancy, can provide insights towards elucidating the mechanisms that drive BP changes during pregnancy.
Emotional intelligence: Part 1: The development of scales and psychometric testing
Authors: Akerjordet Kristin , Severinsson Elisabeth
Published: March 2009

Abstract  This article, the first in a series of four, describes the development of two scales for deductive and inductive measurement of emotional intelligence (EI), based on the literature and the identification of the psychometric properties of the scales. The data collection comprised two parts: (i) a literature search on the subject of emotional intelligence; and (ii) psychometric testing of the scales. The Emotional Intelligence Scale, comprising 23 items, and the Emotional Reactions and Thoughts Scale, containing 25 items, were tested on a sample of 250 postnatal mothers. The response rate was 80%. An explorative factor analysis was used to investigate the construct validity of the underlying dimensions of emotional intelligence and yielded a three‐factor solution for the Emotional Intelligence Scale and a four‐factor solution for the Emotional Reactions and Thoughts Scale. The internal consistency of the scales was satisfactory. How well the factor solutions fit in clinical practice remains to be validated.
Glutamate induces directed chemotaxis of microglia
Authors: Liu Guo Jun , Nagarajah Rajini , Banati Richard B. , Bennett Max R.
Published: March 2009

Microglia in the brain possess dynamic processes that continually sample the surrounding parenchyma and respond to local insults by rapidly converging on the site of an injury. One of the chemotaxic agents responsible for this response is ATP. Here we show that the transmitter glutamate is another such chemotaxic agent. Microglia exposed to glutamate increase their cell membrane ruffling and migrate to a source of glutamate in cell culture and in spinal cord slices. This chemotaxis is meditated by α‐amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid (AMPA) and metabotropic glutamate receptors on the microglia. Chemotaxis is dependent on redistribution of actin filaments in the cells and on tubulin following receptor activation. Thus glutamate, which is released at synapses as well as from damaged cells, can mediate rapid chemotaxic responses from microglial cells.
Recovery of motor and cognitive function after cerebellar lesions in a songbird – role of estrogens
Authors: Spence Rory D. , Zhen Yin , White Stephanie , Schlinger Barney A. , Day Lainy B.
Published: March 2009

In addition to its key role in complex motor function, the cerebellum is increasingly recognized to have a role in cognition. Songbirds are particularly good models for the investigation of motor and cognitive processes but little is known about the role of the songbird cerebellum in these processes. To explore cerebellar function in a songbird, we lesioned the cerebellum of adult female zebra finches and examined the effects on a spatial working memory task and on motor function during this task. There is evidence for steroid synthesis in the songbird brain and neurosteroids may have an impact on some forms of neural plasticity in adult songbirds. We therefore hypothesized that neurosteroids would affect motor and cognitive function after a cerebellar injury. We found that cerebellar lesions produced deficits in motor and cognitive aspects of a spatial task. In line with our prediction, birds in which estrogen synthesis was blocked had impaired performance in our spatial task compared with those that had estrogen synthesis blocked but estrogen replaced. There was no clear effect of estrogen replacement on motor function. We also found that lesions induced expression of the estrogen synthetic enzyme aromatase in reactive astrocytes and Bergmann glia around a cerebellar lesion. These data suggest that the cerebellum of songbirds mediates both motor and cognitive function and that estrogens may improve the recovery of cognitive aspects of cerebellar function after injury.