bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase behavior of a suspension of colloidal hard rods and nonadsorbing polymer
Authors: Savenko S. V. , Dijkstra Marjolein
Published: June 2006

We study the phase behavior of a mixture of colloidal hard rods with a length-to-diameter ratio of L∕σc=5 and nonadsorbing ideal polymer. We map our binary mixture onto an effective one-component system by integrating out the degrees of freedom of the polymer coils. We derive a formal expression for the exact effective Hamiltonian of the colloidal rods, i.e., it includes all effective many-body interactions and it is related to the exact free volume available for the polymer. We determine numerically on a grid the free volume available for the ideal polymer coils “on the fly” for each colloidal rod configuration during our Monte Carlo simulations. This allows us to go beyond first-order perturbation theory, which employs the pure hard-rod system as reference state. We perform free energy calculations for the isotropic, nematic, smectic, and crystal phase using thermodynamic integration and common tangent constructions are used at fixed polymer fugacities to map out the phase diagram. The phase behavior is determined for size ratios q=σp∕σc=0.15, 0.5, and 1, where σp is the diameter of the polymer coils. The phase diagrams based on the full effective Hamiltonian are compared with those obtained from first-order perturbation theory, from simulations using the effective pair potential approximation to the effective Hamiltonian, and with those based on an empiric effective depletion potential for the rods. We find that the many-body character of the effective interactions stabilizes the nematic and smectic phases for large q, while the effective pair potential description overestimates the attractive interactions and favors, hence, a broad isotropic-crystal coexistence.
Plasma diagnostic system using optical fibers with high numerical aperture
Authors: Ohkuma Yasunori , Kanamaru Yuki , Hasegawa Yoshinori , Fujino Toshiyuki , Fujimoto Kayoko , Gota Hiroshi , Asai Tomohiko , Takahashi Tsutomu , Nogi Yasuyuki
Published: June 2006

A diagnostic system using optical fibers with high numerical apertures is constructed for investigating a structure of magnetically confined plasma. Since the fiber has no convex lens at its front facet, the radiation from all plasmas included in the viewing angle of the fiber is utilized. First, theoretical forms are derived to determine the structure of the plasma from optical signals of a few fibers arranged axisymmetrically around the plasma. Second, the numerical aperture is measured by a simple method using a circular fluorescent lamp. Third, the theoretical forms are ascertained by a mock-up experiment where a light source representing a model plasma is constructed by a matrix array of straight fluorescent lamps. In this experiment, the effect of a reflected light from a wall of a vacuum vessel is investigated. Finally, the optical system is applied to a field-reversed-configuration plasma. Obtained structures of the plasma for n=1 and 2 toroidal modes are compared with the results of the conventional method using the fibers with convex lenses. The former results agree well with the latter ones in spite of the use of one-sixth the number of fibers in the latter method.
Optical absorption and electrical transport in hybrid TiO2 and polymer nanocomposite films
Authors: Zhou Xi-Song , Li Zheng , Wang Ning , Lin Yuan-Hua , Nan Ce-Wen
Published: June 2006

Hybrid nanofilms of poly(2-methoxy-5-ethylhexyloxy-1,4-phenylene)vinylene (MEH-PPV) and anatase-TiO2 nanoparticles were prepared. The results showed that the optical absorption spectra and electrical transport properties of the TiO2∕MEH-PPV nanocomposite films were strongly dependent on the particle size and concentration of TiO2 nanoparticles in the hybrid films. In comparison with pure TiO2 nanofilms, the hybrid TiO2∕MEH-PPV films presented a shift of the absorption edge to the lower-energy region, and an obvious nonlinear current-voltage characteristic.
Iterative fluctuation charge model: A new variable charge molecular dynamics method
Authors: Ma Ying , Garofalini Stephen H.
Published: June 2006

In molecular simulations, calculation of environmentally dependent atomic charges is still a demanding task. Empirical and semiempirical methods have been proposed and applied to a wide range of problems with different success. In this paper, a new scheme based on the concept of electronegativity equalization is presented and its advantages over several other methods are discussed. This method is an extension of the fluctuation charge model [S. W. Rick, S. J. Stuart, and B. J. Berne, J. Chem. Phys. 101, 6141 (1994)]. By allowing multiple electronic iterations at each nuclear step, the condition of electronegativity equalization can be satisfied to a selected precision. Molecular dynamics simulations using this new method, as well as several other methods, are performed on α quartz. Analysis of the simulated results shows that it is advantageous to use the iterative fluctuation charge model in several different situations.
Aperture-size-controlled optical fiber tips for high-resolution optical microscopy
Authors: Chevalier N. , Sonnefraud Y. , Motte J. F. , Huant S. , Karrai K.
Published: June 2006

A method is developed to produce chemically etched optical tips for near-field and confocal microscopies with valuable properties such as large transmission and no lateral light leaks. Prior to metal coating, tips are coated with a dielectric material, MgF2, that is refraction-index-matched to silica. It is shown that adjusting the MgF2 layer thickness allows us to control the tip aperture size in the diameter range from 70to500nm. First, near-field fluorescence imaging of latex nanospheres with the smallest optical aperture tips confirms their ability to reach subwavelength optical resolution. In addition, thanks to their high transmission and collection efficiencies as well as their natural achromatism, it is proposed that the large optical aperture tips be advantageously substituted to high numerical aperture objectives in some confocal microscopes operating in constrained environments such as at low temperature.
Flame synthesis of aligned tungsten oxide nanowires
Authors: Xu Fusheng , Tse Stephen D. , Al-Sharab Jafar F. , Kear Bernard H.
Published: June 2006

Aligned single-crystal WO2.9 nanowires are grown directly from tungsten substrates at high rates using a flame synthesis method. The nanowires have diameters of 20–50nm, lengths >10μm, coverage density of 109–1010cm−2, and growth rates >1μm∕min. Growth occurs by the vapor-solid mechanism, with local gas-phase temperature (∼1720K) and chemical species (O2, H2O, and H2) strategically specified at the substrate for self-synthesis. Advantages of this synthesis method are reduced processing times, absence of necessity for substrate pretreatment or catalysts, scalability for large-area surface coverage, high purity and yield of oriented nanowires, and continuous processing conditions.
Cobalt nanorods fully encapsulated in carbon nanotube and magnetization measurements by off-axis electron holography
Authors: Fujita Takeshi , Hayashi Yasuhiko , Tokunaga Tomoharu , Yamamoto Kazuo
Published: June 2006

Fully encapsulated face-centered-cubic (fcc) Co nanorods in multiwalled carbon nanotubes were produced by microwave plasma enhanced chemical vapor deposition. Quantitative magnetization measurements of the Co nanorods were carried out by off-axis electron holography using a theoretical cylindrical model. The component of magnetic induction was then measured to be 1.2±0.1T, which is lower than the expected saturation magnetization of fcc Co of 1.7T. The reason for the reduced magnetic component was discussed.
Homeland as Social Construct: Territorialization among Kazakhstan's Germans and Koreans
Authors: Diener Alexander
Published: June 2006

Among the most pressing tasks confronting leaders of the Central Asian states is the reconciliation of their desire to expedite legitimation of rule by reifying titular cultural paradigms with the need to construct inclusive civic modes of national self-conception. Kazakhstan is perhaps the best example from the region wherein the construction of a multicultural, inclusive homeland concept is essential to the future of the state. The poignancy of Kazakhstan's situation relates to the fact that its population consists of nearly equal numbers of titular and non-titular peoples, often living compactly in different regions of the state. Large-scale migration of predominately European ethnic minorities from Kazakhstan's territory since the late Soviet period has coupled with high birth rates among ethnic Kazakhs and the “return migration” of diasporic Kazakhs to elevate the titular community to a 53.4% majority (from 40.1 in 1989).
Meta‐analysis in sport and exercise research: Review, recent developments, and recommendations
Authors: Hagger M.S.
Published: June 2006

The purpose of this article is to provide a general overview of the principles and practice of conducting quantitative psychometric meta‐analytic reviews in the sport and exercise sciences and highlight some of the recent developments and recommendations from researchers regarding the conduct and validity of meta‐analytic methods. After outlining the historical context, the general principles involved in a quantitative cumulation of research findings across empirical studies is reviewed. Subsequently, recent controversies and issues surrounding the use of meta‐analysis are reviewed with examples provided from the sport and exercise psychology literature. Specifically, the basis for and selection of meta‐analytic models (use of fixed vs. random effects models), the treatment of data from theories that explicitly demand testing the effects of multiple independent variables on a dependent variable (use of multiple regression), and how to treat studies that contain multiple tests of a given effect (use of averaging and structural equation modeling methods) are covered. Recommendations are provided for researchers conducting meta‐analytic studies based on these issues.
Strategies in treatment of tendon overuse injury. The chronic painful tendon
Authors: Alfredson Håkan
Published: June 2006

The etiology and pathogenesis to chronic tendon pain is unknown, and treatment is known to be difficult. Treatment is often based on opinions and not findings in scientific studies.

Recent research, using the intra‐tendinous microdialysis technique, has shown that in chronic painful Achilles‐, patellar‐, and extensor carpi radialis brevis (ECRB) tendons, there were no signs (normal Prostaglandin‐2 levels) of a so‐called chemical inflammation. Furthermore, in biopsies from chronic painful Achilles tendons, pro‐inflammatory cytokines were not up‐regulated, again showing the absence of an intra‐tendinous inflammation. Consequently, if the purpose is to treat a chemical inflammation, there is no science backing up for treatment of theses conditions with anti‐inflammatory agents (NSAIDs, corticosteroidal injections). Interestingly, Substance‐P (SP) and Calcitonin Gene Regulated Peptide (CGRP) nerves have been demonstrated in close relation to vessels in biopsies from these chronic painful tendons, indicating the existence of a possible so‐called neurogenic inflammation.

Using ultrasonography (US) + color Doppler (CD), and immunhistochemical analyses of biopsies, a vasculo/neural(SP‐ and CGRP‐nerves) ingrowth in the chronic painful tendinosis tendon, but not in the pain‐free normal tendon, has recently been found. A specially designed treatment, using US‐ and CD‐guided injections of the sclerosing agent Polidocanol, targeting the neovessels outside the tendon, has in pilot studies on chronic painful Achilles‐, and patellar tendons been shown to cure the tendon pain in the majority of patients. A recent randomized double‐blind study, verified the importance of injecting the sclerosing substance Polidocanol.
MARK2/EMK1/Par-1Bα Phosphorylation of Rab11-Family Interacting Protein 2 Is Necessary for the Timely Establishment of Polarity in Madin-Darby Canine Kidney Cells
Authors: Ducharme Nicole A. , Hales Chadwick M. , Lapierre Lynne A. , Ham Amy-Joan L. , Oztan Asli , Apodaca Gerard , Goldenring James R.
Published: June 2006

Rab11a, myosin Vb, and the Rab11-family interacting protein 2 (FIP2) regulate plasma membrane recycling in epithelial cells. This study sought to characterize more fully Rab11-FIP2 function by identifying kinase activities modifying Rab11-FIP2. We have found that gastric microsomal membrane extracts phosphorylate Rab11-FIP2 on serine 227. We identified the kinase that phosphorylated Rab11-FIP2 as MARK2/EMK1/Par-1Bα (MARK2), and recombinant MARK2 phosphorylated Rab11-FIP2 only on serine 227. We created stable Madin-Darby canine kidney (MDCK) cell lines expressing enhanced green fluorescent protein-Rab11-FIP2 wild type or a nonphosphorylatable mutant [Rab11-FIP2(S227A)]. Analysis of these cell lines demonstrates a new role for Rab11-FIP2 in addition to that in the plasma membrane recycling system. In calcium switch assays, cells expressing Rab11-FIP2(S227A) showed a defect in the timely reestablishment of p120-containing junctional complexes. However, Rab11-FIP2(S227A) did not affect localization with recycling system components or the normal function of apical recycling and transcytosis pathways. These results indicate that phosphorylation of Rab11-FIP2 on serine 227 by MARK2 regulates an alternative pathway modulating the establishment of epithelial polarity.
Gab1 Is Required for Cell Cycle Transition, Cell Proliferation, and Transformation Induced by an Oncogenic Met Receptor
Authors: Mood Kathleen , Saucier Caroline , Bong Yong-Sik , Lee Hyun-Shik , Park Morag , Daar Ira O.
Published: June 2006

We have shown previously that either Grb2- or Shc-mediated signaling from the oncogenic Met receptor Tpr-Met is sufficient to trigger cell cycle progression in Xenopus oocytes. However, direct binding of these adaptors to Tpr-Met is dispensable, implying that another Met binding partner mediates these responses. In this study, we show that overexpression of Grb2-associated binder 1 (Gab1) promotes cell cycle progression when Tpr-Met is expressed at suboptimal levels. This response requires that Gab1 possess an intact Met-binding motif, the pleckstrin homology domain, and the binding sites for phosphatidylinositol 3-kinase and tyrosine phosphatase SHP-2, but not the Grb2 and CrkII/phospholipase Cγ binding sites. Importantly, we establish that Gab1-mediated signals are critical for cell cycle transition promoted by the oncogenic Met and fibroblast growth factor receptors, but not by progesterone, the natural inducer of cell cycle transition in Xenopus oocytes. Moreover, Gab1 is essential for Tpr-Met–mediated morphological transformation and proliferation of fibroblasts. This study provides the first evidence that Gab1 is a key binding partner of the Met receptor for induction of cell cycle progression, proliferation, and oncogenic morphological transformation. This study identifies Gab1 and its associated signaling partners as potential therapeutic targets to impair proliferation or transformation of cancer cells in human malignancies harboring a deregulated Met receptor.
Is Causal-Process Observation an Oxymoron?
Authors: Beck Nathaniel
Published: June 2006

When I first read King, Keohane, and Verba (1994) (KKV), I was excited by the general theme of what seemed to me the obvious, but usually unspoken, idea that all political scientists, both quantitative and qualitative, are scientists and governed by the same scientific standards. KKV, as Henry Brady (Brady and Collier 2004, chap. 3) cleverly notes, clearly were preaching to the qualitative researcher, and the subject of the sermon was that qualitative researchers should adopt many of the ideas standard in quantitative research. Thus, to abuse both the metaphor and KKV, one might compare KKV to the view of the Inquisition that we are all God's children. But, having sat through many talks based on case studies, it is clear to me that getting everyone to think about the nature of the scientific enterprise we are all engaged in can only be a good thing.
The deficiency ofAkt1is sufficient to suppress tumor development inPten+/−mice
Authors: Chen Mei-Ling , Xu Pei-Zhang , Peng Xiao , Chen William S. , Guzman Grace , Yang Ximing , Di Cristofano Antonio , Pandolfi Pier Paolo , Hay Nissim
Published: June 2006

The tumor suppressor PTEN is frequently inactivated in human cancers. A major downstream effector of PTEN is Akt, which is hyperactivated via PTEN inactivation. It is not known, however, whether diminished Akt activity is sufficient to inhibit tumorigenesis initiated by Pten deficiency. Here we showed that the deficiency ofAkt1is sufficient to dramatically inhibit tumor development inPten+/−mice. Akt1 deficiency had a profound effect on endometrium and prostate neoplasia, two types of human cancer, in which PTEN is frequently mutated, and also affected thyroid and adrenal medulla tumors and intestinal polyps. Even haplodeficiency of Akt1 was sufficient to markedly attenuate the development of high-grade prostate intraepithelial neoplasia (PIN) and endometrial carcinoma. These results have significant implications for cancer therapy.
Interventions for treating the posterior interosseus nerve syndrome: a systematic review of observational studies
Authors: Huisstede Bionka M. A. , Miedema Harald S. , Van Opstal Twan , De Ronde Manon T. M. , Kuiper Judith I. , Verhaar Jan A. N. , Koes Bart W.
Published: June 2006

Abstract  For the posterior interosseus nerve syndrome (PINS), no randomised controlled trials or controlled clinical trials about the effectiveness of interventions are available; only case series can be found. Although the validity of case series is inferior to controlled trials, they may provide valuable data about the efficacy of treatment options. Therefore, we systematically reviewed all available observational studies on treatment of PINS. A literature search and additional reference checking was done. On the basis of previous checklists, we constructed a quality assessment and rating system to analyse the included case series. Studies with less than 50% of the maximum points on the methodological quality assessment were excluded from the analysis. The results are summarised according to a rating system for the strength of the scientific evidence. Six eligible case series for this review were found. After the data extraction and methodological quality assessment, two higher quality studies that evaluated the effectiveness of surgical decompression of the PIN were included in the final analysis. There is a tendency for the effectiveness of surgical decompression of the PIN in patients with PINS. The effectiveness of a conservative treatment for PINS is unknown because no higher quality studies are available. Additional high‐quality controlled studies are needed to assess the level of ‘conclusive evidence’ for surgical treatment. There is also a need for high‐quality controlled trials into the effectiveness of conservative treatments for PINS.
Small‐fibre neuropathy in female Fabry patients: reduced allodynia and skin blood flow after topical capsaicin
Authors: Moller Anette T. , Feldt‐Rasmussen Ulla , Rasmussen Åse K. , Sommer Claudia , Hasholt Lis , Bach Flemming W. , Kølvraa Steen , Jensen Troels S.
Published: June 2006

Abstract  Fabry disease is a rare X‐linked lysosomal storage disorder. The mutations result in a deficiency of the lysosomal enzyme α‐galactosidase A causing accumulation of glycosphingolipids in the vascular endothelial cells and many other tissues. Given the X‐linked inheritance, male patients are severely affected. Recently, attention has been drawn to female patients whether they also show signs of nerve involvement. An early sign of the disease is painful small‐fibre neuropathy. The aim of this study was to evaluate a small‐fibre dysfunction in female Fabry patients by using capsaicin applied topically. The response to capsaicin was evaluated by laser Doppler imaging. We found that the female Fabry patients had a significantly smaller increase in blood flow (p = 0.0003) after capsaicin application. The area of static mechanical allodynia and dynamic mechanical hyperalgesia was also significantly smaller (p = 0.006) in female Fabry patients. This indicates that female Fabry patients have a significant loss of small‐fibre function and demonstrates that it is possible to evaluate this by a non‐invasive method.
Recovery of neurophysiological features with time after rat sciatic nerve repair: a magneto‐neurographic study
Authors: Smit Xander , De Kool B. S. , Blok Joleen H. , Visser Gerhard H. , Hovius Steven E. R. , Van Neck Johan W.
Published: June 2006

Abstract  Experimental assessment of peripheral nerve regeneration in rats by electrophysiology is controversial due to low reproducibility of electrophysiological indicators and diminished quantitative evaluation in conventional experimental set‐ups. Magnetoneurography (MNG) counteracts these drawbacks by magnetically recording electrophysiological signals ex vivo, thereby providing accurate and quantitative data. In 50 rats, sciatic nerve transection was followed by direct repair. MNG outcome parameters, footprints [static toe spread factor (TSF); function] and muscle weight (MW) were studied for their recovery pattern from 2 to 24 weeks. By using MNG, we showed that the regeneration process still continues when functional recovery (static TSF) becomes stagnant. With regression analysis, MNG parameters amplitude, amplitude area and conduction velocity (CV) demonstrated moderate significant correlation with MW, whereas CV was not significantly associated with static TSF. No significant association exists between MW and static TSF. A Kaplan–Meier survival curve revealed that autotomy/contracture of rat hind paws was not related to decreased MNG outcome values. In conclusion, this study highlights and discusses the dissimilarities between direct (MNG) and indirect (static TSF and MW) assessment techniques of the regeneration process. We emphasise the significance of MNG as a direct derivative of axon regeneration in experimental rat studies. Additionally, we stress the must for right‐left ratios, as neurophysiological indicators vary with age, and we confute possible bias in footprint analysis caused by exclusion of autotomy/contracture animals.
The health of caregivers for children with disabilities: caregiver perspectives
Authors: Murphy N. A. , Christian B. , Caplin D. A. , Young P. C.
Published: June 2006

Background  There are an estimated 5.9 million children with severe disabilities in the USA, and most of them are cared for at home by their parents and families. Indirect evidence suggests that poor caregiver health may contribute to recurrent hospitalizations and out‐of‐home placements for children with chronic conditions and disabilities. Greater knowledge of caregiver health‐related needs would allow for the improvement of existing services and the development of new strategies to sustain caregivers in their vital roles. This study explores caregiver perspectives of the health implications of long‐term informal caregiving for children with disabilities.

Methods  Forty parents/caregivers of children with disabilities residing in urban, suburban and rural regions of Utah completed questionnaires and participated in focus groups that explored their feelings regarding their current physical and emotional health and the factors that they viewed as either impairing or promoting their health. The sessions were audiotaped and transcribed. Summary statistics were generated for the questionnaire responses. Focus group content was analysed according to emerging themes and patterns in clusters of information.

Results  The caregiving experience was captured by five themes: (i) stress of caregiving; (ii) negative impact on caregiver health; (iii) sharing the burden; (iv) worry about the future; and (v) caregiver coping strategies. Forty‐one per cent of the caregivers reported that their health had worsened over the past year, and attributed these changes to a lack of time, a lack of control and decreased psychosocial energy.

Conclusions  Caregivers of children with disabilities describe negative physical, emotional and functional health consequences of long‐term, informal caregiving. They have important insights regarding those aspects of caregiving that have positive and negative influences on their health. Interventions that address these issues may have the potential to positively impact caregiver health.
Modelling water, carbon and nitrogen dynamics in soil covered with decomposing mulch
Authors: Findeling A. , Garnier P. , Coppens F. , Lafolie F. , Recous S.
Published: June 2006

A decomposing mulch of residues on the soil affects strongly the water, carbon and nitrogen cycling in the soil. The mulch generates complex and interacting effects that remain difficult to quantify and model. An original mulch module was developed and implemented in the PASTIS model to account for the main biological and physical effects of decomposing mulch. In the extended model, PASTISmulch, the formalism splits the mulch into a decomposable layer in contact with the soil and an overlying not decomposable layer that ‘feeds’ the former. The model was calibrated on laboratory data derived from mulched soil columns experiments. Two types of residues were tested: rape residues made of large elemental particles (length, 10 mm; width, 3–10 mm; thickness, 0.1–8 mm) with a C:N ratio of 29, and rye residues consisting of smaller particles (length, 10 mm; width, 2 mm; thickness, 0.1 mm) with a smaller C:N ratio of 16. Calibration showed that mulch parameters were dependent on the type of residue. The model run with calibrated parameters provided good simulations of the water, carbon and nitrogen dynamics, with global efficiencies greater than 0.8. The sensitivity analysis carried out on seven key parameters showed that the total mulch dry mass and the proportion of this dry mass in contact with the soil are decisive parameters. PASTISmulch highlighted that mulch decomposition was not a continuous process but occurred in the form of successive pulses that correspond to favourable hydric conditions.
Acceptance and denial: implications for people adapting to chronic illness: literature review
Authors: Telford Kerry , Kralik Debbie , Koch Tina
Published: June 2006

Aim.  This paper reports an exploration of the terms acceptance and denial by exploring the literature, with the aim of understanding the implications of using these concepts to categorize people's responses to living with chronic illness.

Background.  People learning to live with a chronic illness or condition may be judged and labelled by others as being in denial, particularly when they do not adhere to prescribed treatment regimes.

Method.  A literature search for the period between 1989 and 2003 was conducted using the electronic databases Medline, CINAHL, PSYCArticles, Health Source Nursing/Academic Edition, Academic Search Elite and Sociological Abstracts. Key terms used were ‘acceptance and denial’ and variations of such themes as ‘chronic illness’, ‘disability’, ‘adjustment’, ‘illness discourse’, ‘medical discourse’, ‘illness experience’, ‘labelling’, ‘self’ and ‘identity’.

Discussion.  The theoretical background of the common constructs ‘acceptance and denial’ are discussed using the psychoanalytic theories of Freud and Kubler‐Ross's work on death and dying. Healthcare professionals and lay people commonly refer to the terms acceptance and denial when describing a person's response to chronic illness. Those whose understanding of the illness experience relies on the acceptance–denial framework may not listen when people with chronic illness attempt to tell their own unique story of how they have experienced life with illness. Instead, their listening antennae may be focused on fitting aspects of the experience with stages of adjustment. When others use labels of acceptance and denial, people who are learning to live with a chronic illness may internalize these labels as reflections of the self. This may be most likely when the person using the label is perceived to have authority, such as a healthcare professional. The internalization of negative information associated with these labels may obstruct the reshaping of self‐identity that is fundamental when making a transition to living well with chronic illness.

Conclusion.  Healthcare professionals are urged to challenge the stage model of adjustment as a way of understanding the response to illness and to listen instead to the stories people tell. They are encouraged to privilege the person's experience as the basis for developing a sensitive, client‐focussed response that takes into account the wider social context of people's lives as well as the medical aspects.
Perceptions of lesbian, gay and bisexual people of primary healthcare services
Authors: Neville Stephen , Henrickson Mark
Published: June 2006

Aim.  This paper reports a study exploring people's perceptions of disclosure about lesbian, gay and bisexual identity to their primary healthcare providers.

Background.  Disclosure of sexual identity to healthcare professionals is integral to attending to the health needs of lesbian, gay and bisexual populations, as non‐disclosure has been shown to have a negative impact on the health of these people. For example, an increased incidence of suicide, depression and other mental health problems have been reported.

Method.  From April to July 2004, a national survey of lesbian, gay and bisexual persons was carried out in New Zealand. Participants were recruited through mainstream and lesbian, gay and bisexual media and venues, and 2269 people completed the questionnaire, either electronically or via hard copy. The 133‐item instrument included a range of closed‐response questions in a variety of domains of interest.

Results.  In this paper, we report results from the health and well‐being domain. More women than men identified that the practitioner's attitude toward their non‐heterosexual identity was important when choosing a primary healthcare provider. Statistically significantly more women than men reported that their healthcare provider usually or always presumed that they were heterosexual and in addition more women had disclosed their sexual identity to their healthcare provider.

Conclusion.  Nurses need to reconsider their approach to all users of healthcare services by not assuming everyone is heterosexual, integrating questions about sexual identity into health interviews and ensuring that all other aspects of the assessment process are appropriate and safe for lesbian, gay and bisexual people.
Spiritual care: implications for nurses’ professional responsibility
Authors: Van Leeuwen René , Tiesinga Lucas J , Post Doeke , Jochemsen Henk
Published: June 2006

Aim.  This paper aimed to gain insight into the spiritual aspects of nursing care within the context of health care in the Netherlands and to provide recommendations for the development of care in this area and the promotion of the professional expertise of nurses.

Background.  International nursing literature suggests that caregivers are expected to pay attention to spiritual aspects of patient care. In Dutch nursing literature, the spiritual dimension is increasingly becoming a focus of attention. Despite this, there is a lack of empirical data from professional practice in the Netherlands.

Method.  Data were collected by means of focus group interviews. The sample was made up of the specialist fields of cardiology, oncology and neurology and divided into groups of patients, nurses and hospital chaplains. The interviews took place between May and December 2004. Data were qualitatively analysed using the computer programme Kwalitan.

Results.  Different spiritual themes emerged from the interviews. There were different expectations of the nurse's role with regard to spiritual aspects. The main themes derived from this research can be recognized as aspects of nursing competencies that are reported in the literature. However, the attention to spiritual aspects in the nursing process is not clear cut. It seems to be highly dependent on personal expression and personal commitment.

Conclusions.  The study raises questions about the nurse's professional role in spiritual care. The study shows that different factors (personal, cultural and educational) play a role in the fact that spiritual care is not structurally embedded in nursing care. Further research on the impact of that variable is recommended.

Relevance to clinical practice.  Nursing care implies care for the spiritual needs of patients. To provide this care, nurses need to be knowledgeable regarding the content of spiritual care and the personal, professional, cultural and political factors influencing it. They also need to be able to participate in policy and decision‐making discussions of spiritual care in clinical nursing practice.
Nursing competencies for spiritual care
Authors: Baldacchino Donia R
Published: June 2006

Aim and objectives.  The aim of this paper is to reveal the main nursing competencies for spiritual care, which emerged from data collecting from qualified nurses in Malta.

Background.  For nurses to deliver spiritual care, they must be competent to provide care on a physical, mental, social and spiritual level. As spiritual care may be influenced by culture, this study explored the competencies for spiritual care from the Maltese nurses’ perspective.

Methods.  A descriptive exploratory study investigated nurses’ competencies in the delivery of spiritual care to patients with myocardial infarction. Data were collected by means of an open‐ended questionnaire on qualified nurses (n = 77) followed by an in‐depth interview on a stratified random sample (n = 14) of nurses from the same respondents.

Results.  The four main nursing competencies identified were associated with the role of the nurse as a professional and as an individual person; delivery of spiritual care by the nursing process; nurses’ communication with patients, inter‐disciplinary team and clinical/educational organizations and safeguarding ethical issues in care.

Conclusion.  This study demonstrated the complexity of spiritual care, which requires nurses to increase their awareness of the uniqueness of each individual patient with regard to the connection between mind, body and spirit; the assessment of the spiritual status of patients during illness and the implementation of holistic care as recommended by the Nursing Code of Ethics.

Relevance to clinical practice.  These findings will enable nurses to consider the importance of spiritual care, which may allow them to help empower patients find meaning and purpose during times of illness. More emphasis should be put on spiritual care in the pre‐ and postregistration education. Further research to translate these main competencies into specific competencies will guide spiritual care.
Determination of intrathyroidal iodine by X‐ray fluorescence analysis in 60‐ to 65‐year olds living in an iodine‐sufficient area
Authors: MILAKOVIC M. , BERG G. , EGGERTSEN R. , NYSTRÖM E. , OLSSON A. , LARSSON A. , HANSSON M.
Published: June 2006

Objectives.  X‐ray fluorescence (XRF) is a non‐invasive method for determining the iodine content of the thyroid gland in vivo. In spite of the obvious clinical value of such a method in situations of iodine deficiency or iodine overload, the method has not so far been widely used. The objective was to investigate the applicability of the XRF method in a larger number of subjects.

Design and subjects.  The study comprised 37 individuals, aged 60–65 years, who had spent their entire life with iodine supplementation through iodinated table salt. Individuals with (previous) thyroid disease were excluded. The individual thyroid function had previously been evaluated by measurements of thyroid‐related hormones, thyroid volume and 131‐Iodine (131I) uptake which indicated a sufficient iodine intake of the population in the area. Iodine in the right thyroid lobe in each subject was examined using XRF.

Results.  The mean thyroid iodine concentration was 0.4 mg mL−1, corresponding to a mean total iodine content of 5.2 mg (range 0.9–20.2). There was a pronounced difference between individuals. No correlation was found between iodine concentration and 131I uptake or thyroid volume. Neither was iodine content and 131I uptake correlated.

Conclusions.  In a population living under iodine‐sufficient conditions, a large variation of iodine stored in the thyroid is compatible with euthyroidism. Determination of the iodine pool by XRF investigation is feasible in a clinical setting and the method offers a unique possibility to study the intrathyroidal iodine pool in subjects with thyroid disease. The low radiation dose enables the use of the method in pregnant women and also in young individuals.
Sex Differences in Oestrogen‐Induced p44/42 MAPK Phosphorylation in the Mouse Brain In Vivo
Authors: Barabás K. , Szegõ É. M. , Kaszás A. , Nagy G. M. , Juhász G. D. , Ábrahám I. M.
Published: June 2006

In addition to the classical direct genomic mechanisms of action, oestrogen also exerts poorly understood, nonclassical effects on the signalling system in neurones. In the present study, we investigated whether sex differences exist in gonadectomy‐ and oestrogen‐induced effects on p44/42 mitogen‐activated protein kinase (MAPK) phosphorylation in specific brain regions of mice. We demonstrate that MAPK immunoreactivity was not altered by gonadectomy or oestrogen treatment in either sex. However, we show that the level of phosphorylated MAPK (pMAPK) within the anteroventral periventricular nucleus (AVPV) was consistently higher in males than females irrespective of gonadal steroid hormone status. In addition, gonadectomy was found to decrease pMAPK immunoreactivity within the piriform cortex of males. Oestrogen increased pMAPK immunoreactivity in the medial preoptic area and AVPV of females, but failed to have the same effect in male mice. Overall, these results demonstrate a marked sex difference in oestrogen‐induced alteration of MAPK phosphorylation in the brain in vivo.
Alteration in Hypothalamic Neuropeptide Y (NPY) Secretion May Underlie Female Reproductive Ageing: Induction of Steroid‐Induced Luteinising Hormone Surge by NPY in Ovariectomised Aged Rats
Authors: Sahu A.
Published: June 2006

A large body of evidence suggests that a defect in the hypothalamic function may be the primary cause of reproductive ageing in female rats. We have previously shown that luteinising hormone (LH)‐surge associated changes in hypothalamic neuropeptide Y (NPY) gene expression and median eminence (ME) NPY levels seen in young rats do not occur in middle‐aged (MA) rats. The present study examined whether hypothalamic NPY release is altered during the steroid‐induced LH surge in ovariectomised (OVX) MA rats, and whether exogenous NPY initiates steroid‐induced LH surge in OVX old rats. In the first study, NPY release from the ME‐arcuate nucleus, as assessed by the push–pull cannula technique, was significantly increased before and during the progesterone‐induced LH surge in oestrogen (E2)‐primed ovariectomised young rats (2–3 months old). This antecedent increase in NPY release seen in young rats was not apparent in MA rats (11–13 months old) in association with a delayed and attenuated LH surge. In the second study, whereas progesterone failed to induce LH surges in E2‐primed ovariectomised old rats (23–25 months old), intracerebroventricular NPY (0.1–0.5 µg) injections at 1100, 1200 and 13.00 h resulted in LH surge induction in E2 + progesterone‐primed ovariectomised old rats. Because increased hypothalamic NPY synthesis and release is obligatory for the preovulatory LH discharge in young rats, the present findings suggest that alteration in NPY release from the ME‐arcuate nucleus contributes to the delayed and reduced LH surges in MA rats and may be involved in the subsequent loss of the LH surges in old rats.
Sleep and Rest Regulation in Young and Old Oestrogen‐Deficient Female Mice
Authors: Vyazovskiy V. V. , Kopp C. , Wigger E. , Jones M. E. E. , Simpson E. R. , Tobler I.
Published: June 2006

The effect of circulating oestrogen deficiency on sleep regulation and locomotor activity was investigated in aromatase cytochrome P450 deficient mice (ArKO) and wild‐type (WT) controls. Sleep was recorded in 3‐month old mice during a 24‐h baseline day, 6‐h sleep deprivation (SD) and 18‐h recovery, and activity was recorded at the age of 3, 9 and 12 months. In mice deficient of oestrogen, the total amount of sleep per 24 h was the same as in WT controls. However, in ArKO mice, sleep was enhanced in the dark period at the expense of sleep in the light phase, and was more fragmented than sleep in WT mice. This redistribution of sleep resulted in a damped amplitude of slow‐wave activity (SWA; power between 0.75–4.0 Hz) in non‐rapid eye movement sleep across 24 h. After SD, the rebound of sleep and SWA was similar between the genotypes, suggesting that oestrogen deficiency does not affect the mechanisms maintaining the homeostatic balance between the amount of sleep and its intensity. Motor activity decreased with age in both genotypes and was lower in ArKO mice compared to WT at all three ages. After SD, the amount of rest in 3‐month old WT mice increased above baseline and was more consolidated. Both effects were less pronounced in ArKO mice, reflecting the baseline differences between the genotypes. The results indicate that despite the pronounced redistribution of sleep and motor activity in oestrogen deficient mice, the basic homeostatic mechanisms of sleep regulation in ArKO mice remain intact.
Anthrax oedema toxin induces anthrax toxin receptor expression in monocyte‐derived cells
Authors: Maldonado‐Arocho Francisco J. , Fulcher Jennifer A. , Lee Benhur , Bradley Kenneth A.
Published: June 2006

Bacillus anthracis, the causative agent of anthrax, secretes two bipartite toxins that help the bacterium evade the immune system and contribute directly to pathogenesis. Both toxin catalytic moieties, lethal factor (LF) and oedema factor (OF), are internalized into the host‐cell cytosol by a third factor, protective antigen (PA), which binds to cellular anthrax toxin receptors (ANTXRs). Oedema factor is an adenylate cyclase that impairs host defences by raising cellular cAMP levels. Here we demonstrate that oedema toxin (PA + OF) induces an increase in ANTXR expression levels in macrophages and dendritic cells resulting in an increased rate of toxin internalization. Furthermore, we show that increases in ANTXR mRNA levels depends on the ability of OF to increase cAMP levels, is mediated through protein kinase A‐directed signalling and is monocyte‐lineage‐specific. To our knowledge, this is the first report of a bacterial toxin inducing host target cells to increase toxin receptor expression.
Study of an alternate glyoxylate cycle for acetate assimilation by Rhodobacter sphaeroides
Authors: Alber Birgit E. , Spanheimer Regina , Ebenau‐Jehle Christa , Fuchs Georg
Published: June 2006

Organisms, which grow on organic substrates that are metabolized via acetyl‐CoA, are faced with the problem to form all cell constituents from this C2‐unit. The problem was solved by the seminal work of Kornberg and is known as the glyoxylate cycle. However, many bacteria are known to not contain isocitrate lyase, the key enzyme of this pathway. This problem was addressed in acetate‐grown Rhodobacter sphaeroides. An acetate‐minus mutant identified by transposon mutagenesis was affected in the gene for β‐ketothiolase forming acetoacetyl‐CoA from two molecules of acetyl‐CoA. This enzyme activity was missing in this mutant, which grew on acetoacetate and on acetate plus glyoxylate. A second acetate/acetoacetate‐minus mutant was affected in the gene for a putative mesaconyl‐CoA hydratase, an enzyme which catalyses the hydration of mesaconyl‐CoA to β‐methylmalyl‐CoA. β‐Methylmalyl‐CoA is further cleaved into glyoxylate and propionyl‐CoA. These results as well as identification of acetate‐upregulated proteins by two‐dimensional gel electrophoresis lead to the proposal of a new pathway for acetate assimilation. In a first part, affected by the mutations, two molecules of acetyl‐CoA and one molecule CO2 are converted via acetoacetyl‐CoA and mesaconyl‐CoA to glyoxylate and propionyl‐CoA. In a second part glyoxylate and propionyl‐CoA are converted with another molecule of acetyl‐CoA and CO2 to l‐malyl‐CoA and succinyl‐CoA.
Revisiting the glyoxylate cycle: alternate pathways for microbial acetate assimilation
Authors: Ensign Scott A.
Published: June 2006

The glyoxylate cycle, identified by Kornberg et al. in 1957, provides a simple and efficient strategy for converting acetyl‐CoA into anapleurotic and gluconeogenic compounds. Studies of a number of bacteria capable of growth with C2 compounds as the sole carbon source have revealed that they lack the key glyoxylate cycle enzyme isocitrate lyase, suggesting that alternative pathway(s) for acetate assimilation exist in these bacteria. Recent studies of acetate assimilation in methylotrophs and purple phototrophs have revealed remarkable and complex new pathways for assimilation of acetate in the absence of isocitrate lyase. The details of these new pathways are the subject of this MicroCommentary.
Determinants of chemoreceptor cluster formation in Escherichia coli
Authors: Kentner David , Thiem Sebastian , Hildenbeutel Markus , Sourjik Victor
Published: June 2006

Chemotactic stimuli in bacteria are sensed by large sensory complexes, or receptor clusters, that consist of tens of thousands of proteins. Receptor clusters appear to play a key role in signal processing, but their structure remains poorly understood. Here we used fluorescent protein fusions to study in vivo formation of the cluster core, which consists of receptors, a kinase CheA and an assisting protein CheW. We show that receptors aggregate through their cytoplasmic domains even in the absence of other chemotaxis proteins. Clustering is further enhanced by the binding of CheW. Surprisingly, we observed that some fragments of CheA bind receptor clusters well in the absence of CheW, although the latter does assist the binding of full‐length CheA. The resulting mode of receptor cluster formation is consistent with an experimentally observed flexible stoichiometry of chemosensory complexes and with assumptions of recently proposed computer models of signal processing in chemotaxis.