bluuebunny/crossref_metadata_2025 huggingface dataset:
Vacancy Chains Provide Aggregate Benefits To Coenobita clypeatus Hermit Crabs
Authors: Lewis Sara M. , Rotjan Randi D.
Published: March 2009

Vacancy chain theory describes a unique mechanism for the sequential distribution of animal resources across multiple individuals. This theory applies to any resources, such as shelters or nest sites, that are discrete, reusable, and limited in use to single individuals or groups at one time. Hermit crabs rely on gastropod shells for shelter, and a single vacant shell can initiate a chain of sequential shell switches that distributes new resources across many individuals. Using the terrestrial hermit crab Coenobita clypeatus, we examined the previously untested theoretical prediction that this process will yield trickle‐down resource benefits to vacancy chain participants (aggregate benefits). In laboratory experiments, we measured improvements in shell quality when a single vacant shell was provided to groups of eight crabs. We found that crabs participating in vacancy chains (averaging 3.2 individuals) gained significant reductions in their shell crowding. In addition, vacancy chains terminated early when experimental groups included a single crab occupying a damaged shell, because damaged vacancies always remained unoccupied. Hermit crabs in damaged shells were more likely to win resource contests for high quality shells against size‐matched hermit crabs in crowded shells. Finally, field additions of many new shells to an island population of C. clypeatus hermit crabs reduced average shell crowding for crabs of all sizes, possibly from propagation of benefits through vacancy chains. These results provide empirical support for the theoretical prediction that vacancy chains should provide benefits distributed across many vacancy chain participants. Since shelter‐based vacancy chains likely occur in other animals, additional studies of vacancy chain processes should provide new insights into resource acquisition behaviors in diverse animal groups.
Trotskii and Lenin's Funeral, 27 January 1924: A Brief Note
Authors: THATCHER IAN D.
Published: March 2009

Leon Trotskii was fond of recalling Lenin's assessment of Stalin as a ‘cook making only peppery dishes’.1 Out of the many instances in which Trotskii presented Stalin as a sly manipulator, one of the most famous is when Stalin supposedly lied to Trotskii about the date of Lenin's funeral, in this way keeping his rival for power out of the limelight as Stalin posed as Lenin's nearest and dearest mourner. It is a simple and appealing way of making an accusation of mendacious cunning stick, for the first questions that seem to be asked of any funeral are ‘how was the turnout?,’‘who attended?’ This brief note seeks to clarify what Trotskii claimed about his absence from Lenin's funeral and in which texts, for there are different versions. It will also chart how historians have reported this incident. Finally, it will assess how far archival materials that became accessible after communism's collapse can shed new light.
Myocardial perfusion is preserved in patients with psoriasis without clinically evident cardiovascular disease
Authors: Yalcin H , Balci DD , Ucar E , Ozcelik N , Tasci C , Seyfeli E , Akgul F , Yalcin F
Published: March 2009

Background  Psoriasis is associated with a premature atherosclerosis due to the chronic inflammatory process. To evaluate the effect of disease process on myocardial perfusion, we planned to perform 99mTc‐MIBI myocardial perfusion single photon emission computed tomography (SPECT) in patients with psoriasis.

Methods  The study group consisted of 28 psoriasis patients (17 men, 11 women), aged 18‐76 years, and mean age 41.2 ± 14.1 years. The patients were selected among those who were older than 18 years and longer than 10 years of disease duration with more than two times of systemic treatment. All patients underwent 99mTc‐MIBI myocardial perfusion SPECT with the same day protocol.

Results  We detected various risk factors including smoking habits in 7, family history of cardiovascular disease in 4, hypertension in 1, hyperlipidemia in 9 patients. We completed myocardial perfusion SPECT for each patient and found normal perfusion pattern in SPECT images.

Conclusion  We detected that myocardial perfusion is preserved in the patients with psoriasis. The majority of acute heart attacks are caused by noncritical coronary stenosis and this may be an explanation for increased cardiovascular risk in these patients despite normal coronary perfusion.
A geographers’ imperative? Research and action in the aftermath of disaster
Authors: BRUN CATHRINE
Published: March 2009

After the Indian Ocean tsunami of 2004 a number of academics published texts in attempts to make sense of the disaster. Frustrations and feelings of inability to do something useful to assist were expressed. The academic discussions arising from the disaster may be linked with more general discussions around conducting relevant and responsible research in the social sciences. This paper addresses the role of researchers in the aftermath of the tsunami disaster in Sri Lanka and explores how the debate following the tsunami can move on to refine researchers’ roles in geography by way of participatory action research (PAR), a research strategy that has received limited attention in research on disasters. The paper begins by situating the debate in the spatial politics of humanitarian work and academic research. Then discussions that arose among geographers in the aftermath of the tsunami are presented and potentials for conducting responsible research by engaging with the field are introduced. In the final section, starting with the notion of responsible research, how PAR can potentially bring us forward in developing principles and tools for more responsible geographical research in the context of emergencies is discussed.
Effects of the Premier Hospital Quality Incentive Demonstration on Medicare Patient Mortality and Cost
Authors: Ryan Andrew M.
Published: March 2009

Objective. To evaluate the effects of the Premier Inc. and Centers for Medicare and Medicaid Services Hospital Quality Incentive Demonstration (PHQID), a public quality reporting and pay‐for‐performance (P4P) program, on Medicare patient mortality, cost, and outlier classification.

Data Sources. The 2000–2006 Medicare inpatient claims, Medicare denominator files, and Medicare Provider of Service files.

Study Design. Panel data econometric methods are applied to a retrospective cohort of 11,232,452 admissions from 6,713,928 patients with principal diagnoses of acute myocardial infarction (AMI), heart failure, pneumonia, or a coronary‐artery bypass grafting (CABG) procedure from 3,570 acute care hospitals between 2000 and 2006. Three estimators are used to evaluate the effects of the PHQID on risk‐adjusted (RA) mortality, cost, and outlier classification in the presence of unobserved selection, resulting from the PHQID being voluntary: fixed effects (FE), FE estimated in the subset of hospitals eligible for the PHQID, and difference‐in‐difference‐in‐differences.

Data Extraction Methods. Data were obtained from CMS.

Principal Findings. This analysis found no evidence that the PHQID had a significant effect on RA 30‐day mortality or RA 60‐day cost for AMI, heart failure, pneumonia, or CABG and weak evidence that the PHQID increased RA outlier classification for heart failure and pneumonia.

Conclusions. By not reducing mortality or cost growth, this study suggests that the PHQID has made little impact on the value of inpatient care purchased by Medicare.
Subglacial erosion forms in northwest Ireland
Authors: KNIGHT JASPER
Published: March 2009

Subglacial erosional forms are commonly found on bedrock substrates inside the Late Weichselian ice margin in County Donegal, northwest Ireland, and can be used to provide detailed information on subglacial processes and environments. The erosional forms occur on spatial scales from whalebacks (tens of metres in scale), to asymmetric and channelized bedrock‐cut scours (tens of cm in scale) and striations (mm scale). Processes responsible for development of subglacial erosional forms occur along a continuum, from free meltwater existing as a laterally extensive sheet at the ice‐bed interface, to abrasion by basal ice. Channelized bedrock‐cut scours are particularly common in County Donegal, and show asymmetric and meandering thalwegs, U‐shaped cross‐profiles and steep lateral margins. Innermost parts of the scours are highly polished and have striations that follow thalweg direction. In places, bedrock surfaces are overlain by a delicate polish and thin calcite cement, and are buried beneath glacial till. Based on their morphology, the bedrock scours are interpreted as s‐forms caused by high‐pressure subglacial meltwater erosion. Striations within the scoured channels reflect periods of ice‐bed coupling and subglacial abrasion. The range of features observed here was used to consider relationships between subglacial topography, hydraulic processes and ice‐bed coupling. Precipitation of calcite cement took place in depressions on the bedrock surface by CO2 degassing. Infilling of depressions by glacial till formed a new type of ‘sticky spot’ related to spatial variations in subglacial water pressure. The temporal evolution of sticky spots reflects interactions within the subglacial environment between subglacial relief, hydraulic regime and ice‐bed coupling.
Late Middle Pleistocene glaciation in East Anglia, England
Authors: GIBBARD PHILIP L. , PASANEN ANTTI H. , WEST RICHARD G. , LUNKKA JUHA PEKKA , BOREHAM STEVE , COHEN KIM M. , ROLFE CHRISTOPHER
Published: March 2009

Investigation of a group of landforms and their underlying deposits on the eastern margin of the Fenland in East Anglia has demonstrated that they represent a series of glaciofluvial delta‐fan and related sediments. Section logging, borehole records and previous descriptions combine to indicate that the sediments were deposited in ice‐marginal deltaic settings in an ice‐marginal lake. The internal structure and form of the fan‐like deltas has been demonstrated using extensive ground‐penetrating radar investigation. The lake formed by the ice damming westward‐aligned river valleys. Together, this evidence confirms historical descriptions of a glaciation of the Fenland, and clarifies the interpretation of gravels of the eastern Fenland margin. Recent reinterpretations of the latter as of fluvial rather than glacial meltwater origin are shown to be incorrect. It is concluded, on the basis of regional correlation, supported by optically stimulated luminescence dating, that the glaciation occurred at c. 160 kyr, i.e. in the Wolstonian (=Saalian) Stage (broadly equivalent to MIS ?11b‐6). Comparison with The Netherlands' sequence shows a similarity of glacial marginal morphology, and the dates confirm the time equivalence with that during the late Saalian Drenthe Substage, Amersfoort ice‐pushed ridge complex. The implications include that the c. 200 kyr interval, between the Hoxnian (Holsteinian) temperate Stage and the Wolstonian glaciation, was a period during which fluvial and periglacial activity modified the landscape under cold climates, with organic sediments laid down during warmer events. Palaeolithic humans were periodically present during this interval, their artefacts having been reworked by the subsequent glaciation.
Metastable persistence of pelitic metamorphic assemblages at the root of a Cretaceous magmatic arc – Fiordland, New Zealand
Authors: DACZKO N. R. , MILAN L. A. , HALPIN J. A.
Published: March 2009

Four aluminosilicate‐bearing, amphibolite facies pelitic schists sampled from the root of the long‐lived eastern Gondwana continental magmatic arc now exposed in southwest Fiordland, New Zealand, record remarkably different P–T–t histories. The four samples were collected from within 20 km of each other within the Fanny Bay Group and Deep Cove Gneiss near Dusky Sound. Integrated petrography, mineral chemistry, mineral equilibria modelling and in situ electron microprobe chemical dating of monazite shows that the sample of the Fanny Bay Group south of the Dusky Fault records a Carboniferous history with peak conditions of 4–4.5 kbar at 570–590 °C, while one sample of the Deep Cove Gneiss from Long Island records a Cretaceous history with apparent peak conditions of 7.5 kbar at 650 °C. Two other samples of the Deep Cove Gneiss from Resolution Island record mixed Carboniferous and Cretaceous histories with apparent peak conditions of 7 kbar at 650 °C and 3–7 kbar at 640–720 °C. The metapelitic schists on Resolution Island were intruded by arc magmas including the voluminous high‐P Western Fiordland Orthogneiss, yet they lack mineralogical evidence of the Cretaceous high‐P (>12 kbar) event. Analysis of water isopleths in a model system shows that the amount of water accommodated in the rock mineral assemblage increases with pressure. With the exhaustion of all free water, and without the addition of external water, these rocks persisted metastably within the deep arc during the high‐P event. The emplacement of large volumes of diorite (i.e. the Western Fiordland Orthogneiss) into the root of the Early Cretaceous continental magmatic arc did not lead to regional granulite facies metamorphism of the country rock schists, as large volumes of amphibolite facies rock metamorphosed under medium‐P conditions persisted metastably in the deep arc crust.
Self‐Reported Sleep Duration and Hypertension in Older Spanish Adults
Authors: Lopez‐Garcia Esther , Faubel Raquel , Guallar‐Castillon Pilar , Leon‐Muñoz Luz , Banegas Jose R. , Rodriguez‐Artalejo Fernando
Published: March 2009

OBJECTIVES: To examine the association between self‐reported sleep duration, prevalent and incident hypertension, and control of high blood pressure in older adults.

DESIGN: Logistic regression models were used to investigate the associations of interest in a prospective cohort study conducted from 2001 to 2003.

SETTING: Cohort representative of the noninstitutionalized Spanish population.

PARTICIPANTS: Three thousand six hundred eighty‐six persons aged 60 and older.

MEASUREMENTS: Sleep duration was reported in 2001 by asking the participants “How many hours do you usually sleep per day (day and night)” and classified into categories (4–5, 6, 7, 8, 9, and 10–15 h/d. The outcome variables were prevalent hypertension (systolic blood pressure ≥140 mmHg, diastolic pressure ≥90 mmHg, or antihypertensive treatment in 2001), control of blood pressure (systolic blood pressure <140 mmHg and diastolic pressure <90 mmHg in subjects receiving antihypertensive treatment in 2001), and incident hypertension (diagnosis of hypertension during 2001–2003 in individuals with normal pressure in 2001).

RESULTS: Compared with sleeping 7 hours, sleeping more or fewer hours was not significantly associated with prevalent hypertension (odds ratios (ORs) ranged from 0.82 (95% confidence interval (CI)=0.64–1.05) to 1.10 (95% CI 0.83–1.46)), control of blood pressure (ORs ranged from 0.70 (95% CI 0.46–1.08) to 0.97 (95% CI 0.60–1.56)), or incident hypertension (OR ranged from 0.54 (95% CI 0.29–1.01) to 0.83 (95% CI 0.43–1.60)). The results were similar in both sexes.

CONCLUSION: Self‐reported sleep duration is not associated with hypertension in older adults.
Evaluation of an Elderly Faller by Medical Students and Rehabilitation Residents
Authors: Rolita Lydia , Ark Tavinder K. , Moroz Alex , Lanyi Valery , Southwell Julianne , Sutin David
Published: March 2009

As part of the development of a curriculum for medical students and rehabilitation residents at New York University School of Medicine, an Objective Structured Clinical Examination (OSCE) station was developed for formative evaluation. The goal was to determine the existing knowledge and competence of medical students and rehabilitation residents in the analysis and treatment of a geriatric patient with a history of falls. This OSCE station was designed to focus on three specific clinical skills needed in assessing the elderly faller. The OSCE station was a standardized patient (SP) encounter with a 75‐year‐old man presenting with falls. Seventy‐five medical students and 41 rehabilitation medicine residents participated in the study. There was high agreement between the SP and a geriatric physician used to assess performance on gait (Cronbach alpha=0.918) and orthostatic blood pressure (Cronbach alpha=0.887) assessment. Of the medical students, 43.5% did not check orthostatic blood pressure, 56.8% did not evaluate gait, and 92.0% did not consider assistive device prescription. Only 20.0% checked both orthostatic blood pressure and gait. Likewise, 73.8% of residents did not check orthostatic blood pressure, 38.1% did not evaluate gait and 92.9% did not consider assistive device prescription. Only 19.0% checked both orthostatic blood pressure and gait. The results of this examination are alarming and suggest that education regarding the approach to an elderly person who falls is inadequate, leaving students and residents poorly prepared to take care of the “silver tsunami.”
An Exercise Intervention for Breast Cancer Survivors With Bone Loss
Authors: Twiss Janice J. , Waltman Nancy L. , Berg Kris , Ott Carol D. , Gross Gloria J. , Lindsey Ada M.
Published: March 2009

Purpose: (a) to determine if 110 postmenopausal breast cancer survivors (BCS) with bone loss who participated in 24 months of strength and weight training (ST) exercises had improved muscle strength and balance and had fewer falls compared to BCS who did not exercise; and (b) to describe type and frequency of ST exercises; adverse effects of exercises; and participants’ adherence to exercises at home, at fitness centers, and at 36‐month follow up.

Design: Findings reported are from a federally funded multicomponent intervention study of 223 postmenopausal BCS with either osteopenia or osteoporosis who were randomly assigned to an exercise (n=110) or comparison (n=113) group.

Methods: Time points for testing outcomes were baseline, 6, 12, and 24 months into intervention. Muscle strength was tested using Biodex Velocity Spectrum Evaluation, and dynamic balance using Timed Backward Tandem Walk. Adherence to exercises was measured using self‐report of number of prescribed sessions attended and participants’ reports of falls.

Findings: Mean adherence over 24 months was 69.4%. Using generalized estimating equation (GEE) analyses, compared to participants not exercising, participants who exercised for 24 months had significantly improved hip flexion (p=0.011), hip extension (p=0.0006), knee flexion (p<0.0001, knee extension (p=0.0018), wrist flexion (p=0.031), and balance (p=0.010). Gains in muscle strength were 9.5% and 28.5% for hip flexion and extension, 50.0% and 19.4% for wrist flexion and extension, and 21.1% and 11.6% for knee flexion and extension. Balance improved by 39.4%. Women who exercised had fewer falls, but difference in number of falls between the two groups was not significant.

Conclusions: Many postmenopausal BCS with bone loss can adhere to a 24 month ST exercise intervention, and exercises can result in meaningful gains in muscle strength and balance.

Clinical Relevance: More studies are needed for examining relationships between muscle strength and balance in postmenopausal BCS with bone loss and their incidence of falls and fractures.
Perceived and Unmet Needs of Adult Jordanian Family Members of Patients in ICUs
Authors: Omari Ferdous Hasan
Published: March 2009

Purpose: To identify the self‐perceived needs of adult Jordanians who have family members in ICUs and to explore whether those needs were being met.

Design: A descriptive, exploratory design was used. A convenience sample of 139 family members of 85 critically ill patients was recruited from ICUs located in three different types of hospitals in Irbid, a city in northern Jordan. The three types of hospitals included Ministry of Health, university health system, and private sector.

Methods: Family members who participated in this study were instructed to answer all the questionnaires that included: a demographic data form, the Critical Care Family Needs Inventory (CCFNI), and Needs Met Inventory (NMI).

Results: The findings showed that the 10 most important needs identified by adult Jordanian family members were in the Assurance and Information subscales. The need “to be assured that the best care possible is being given to the patient” was reported as the most important need. Use of the NMI indicated that none of the 10 most important needs were perceived as being met.

Conclusions: Jordanian ICU nurses should be prepared to care for families in crisis, and the focus of nursing practice should be moved from just patient‐centered care to a more holistic approach including family needs.

Clinical Relevance: Meeting family needs should be emphasized in nursing practice. Meeting these needs might help family members to cope better and be more supportive to their critically ill loved one.
Tai Chi and Health‐Related Quality of Life in Nursing Home Residents
Authors: Lee Linda Y. K. , Lee Diana T. F. , Woo Jean
Published: March 2009

Purpose:Health‐related quality of life (HRQOL) that is good is regarded as the goal of elderly residential care. However, limited evidence exists indicating a promising intervention that can achieve this goal. The aim of this study is to examine the effect of Tai Chi on HRQOL in nursing home residents.

Design:A nonequivalent pretest‐posttest control‐group design.

Methods:A convenience sample of 139 residents from six nursing homes in Hong Kong was used. The experimental group (n=66) joined a 26‐week Tai Chi program, while the control group (n=73) continued with usual daily activities. The physical and mental components of HRQOL were designated as the dependent variables. Resident satisfaction was considered as a covariate. Doubly multivariate repeated measures analysis of covariance was done to examine the intervention effect.

Findings:After adjusting for the confounding effect of resident satisfaction, a statistically significant difference (p<0.05) in the physical and mental components of HRQOL between the experimental and control groups was found. Findings showed significant improvement in HRQOL after residents practiced Tai Chi.

Conclusions:These investigators contribute additional knowledge about the health benefits of Tai Chi among nursing home residents and indicates support for its use in this population to improve HRQOL.

Clinical Relevance:Tai Chi has unique characteristics as a health exercise that is particularly suitable for nursing home residents. The inclusion of Tai Chi exercise in elderly residential care practice is recommended.
Antecedents of Severe and Nonsevere Medication Errors
Authors: Chang Yun‐Kyung , Mark Barbara A.
Published: March 2009

Purpose: To investigate if differences in antecedents of severe and nonsevere medication errors exist.

Design: A longitudinal study of 6 months of data from 279 nursing units in 146 randomly selected hospitals in the United States (US).

Methods: Antecedents of severe and nonsevere medication errors included work environment factors (work dynamics and RN hours), team factors (communication with physicians and nurses' expertise), person factors (nurses' education and experience), patient factors (age, health status, and previous hospitalization), and medication‐related support services. Generalized estimating equations with a negative binomial distribution were used with nursing units as the unit of analysis.

Findings: None of the antecedents allowed predicting both types of medication errors. Nurses' expertise had a negative and medication‐related support services had a positive association with nonsevere medication errors. Nurses' educational level had a significant nonlinear relationship with severe medication errors only: As the percentage of unit BSN‐prepared nurses increased, severe medication errors decreased until the percentage of BSN‐prepared nurses reached 54%. In contrast, RN experience had a statistically significant relationship with nonsevere medication errors only and nursing units with more experienced nurses reported more nonsevere medication errors.

Conclusions: Severe and nonsevere medication errors might have different antecedents.

Clinical Relevance: Error prevention and management strategies should be targeted to specific types of medication errors for best results.
Validity of Instruments for Measuring Autonomy and Control Over Nursing Practice
Authors: Weston Marla J.
Published: March 2009

Purpose: To review the psychometric properties and evaluate the estimates of validity of commonly used instruments to measure autonomy and control over nursing practice.

Design: Literature review and evaluation of psychometric properties.

Methods: Nursing research reports published in English in peer‐reviewed journals between 1990 and 2007 were examined. Psychometric properties and the actual instrument were reviewed to determine validity for measuring autonomy and control over nursing practice.

Findings and Conclusions: Instruments used to measure autonomy and control over nursing practice are frequently imprecise or inaccurate for measuring the concept of interest. Valid instruments are available to allow measurement of the concepts of clinical autonomy, work autonomy, and control over nursing practice. Clear definitions and valid measures are helpful when communicating and synthesizing nursing knowledge concerning these concepts.

Clinical Relevance: Evaluating the validity of instruments for measuring clinical autonomy, work autonomy, and control over nursing practice can be helpful when organizing and synthesizing the literature related to these concepts, so that strategies to improve professional practice environments becomes more clear.
Light Microscopic Observations, Ultrastructure, and Molecular Phylogeny of Hicanonectes teleskopos n. g., n. sp., a Deep‐Branching Relative of Diplomonads
Authors: PARK JONG SOO , KOLISKO MARTIN , HEISS AARON A. , SIMPSON ALASTAIR G.B.
Published: March 2009

ABSTRACT. We describe Hicanonectes teleskopos n. g., n. sp., a heterotrophic flagellate isolated from low‐oxygen marine sediment. Hicanonectes teleskopos has a ventral groove and two unequal flagella, and rapidly rotates during swimming. At the ultrastructural level H. teleskopos is a “typical excavate”: it displays flagellar vanes, a split right microtubular root, “I,”“B,” and “C” fibres, a singlet microtubular root, and a possible composite fibre. Small subunit rRNA (SSU rRNA) gene phylogenies and an “arched” B fibre demonstrate that H. teleskopos belongs to Fornicata (i.e. diplomonads, retortamonads, and relatives). It forms a clade with the deep‐branching fornicate Carpediemonas, with moderate‐to‐strong bootstrap support, although their SSU rRNA gene sequences are quite dissimilar. Hicanonectes differs from Carpediemonas in cell shape, swimming behaviour, number of basal bodies (i.e. 4 vs. 3), number of flagellar vanes (i.e. 2 vs. 3), anterior root organization, and by having a cytopharynx. Like Carpediemonas and Dysnectes, Hicanonectes has conspicuous mitochondrion‐like organelles that lack cristae and superficially resemble the hydrogenosomes of parabasalids, rather than the mitosomes of their closer relatives the diplomonads (e.g. Giardia).
Pilomatricoma can differentiate not only towards hair matrix and hair cortex, but also follicular infundibulum, outer root sheath and hair bulge
Authors: Kurokawa Ichiro , Yamanaka Kei‐ichi , Senba Yuko , Sugisaki Hitomi , Tsubura Airo , Kimura Tetsunori , Mizutani Hitoshi
Published: March 2009

Abstract:  Pilomatricoma is believed to differentiate towards the hair matrix and hair cortex. To elucidate the origin of differentiation in pilomatricoma, we studied the expression of epithelial keratin (K) and filaggrin (filament aggregating protein) in pilomatricoma. An immunohistochemical study has been made of 53 cases of pilomatricoma using 10 monospecific anti‐keratin antibodies and anti‐filaggrin antibody. Basophilic cells, transitional cells and shadow cells did not react with epithelial keratins and filaggrin antibodies as well as hair matrix and hair cortex. Instead, infundibular‐type epithelium was positive for K1, K10 and filaggrin. Epithelium showing trichilemmal keratinization was positive for K14 and K16. The hair bulge‐like structure was positive for K19. The differentiation of pilomatricoma is diversified, and is heterogeneous in epithelial keratin and filaggrin expression. Our results for keratin and filaggrin expression suggested that pilomatricoma can differentiate not only towards hair matrix and hair cortex, but also follicular infundibulum, outer root sheath and hair bulge.
On the relationship between abiotic stress and co‐occurrence patterns: an assessment at the community level using soil lichen communities and multiple stress gradients
Authors: Maestre Fernando T. , Martínez Isabel , Escolar Cristina , Escudero Adrián
Published: March 2009

The stress‐gradient hypothesis (SGH) predicts a shift from predominant competition to facilitation as abiotic stress increases. Most empirical tests of the SGH have evaluated the interactions between a single or a few pairs of species, have not considered the effects of multiple stress factors, and have not explored these interactions at nested spatial scales. We sampled 63 0.25‐m2 plots, each subdivided into 100 5×5 cm and 25 10×10 cm sampling squares, in a semi‐arid Mediterranean environment to evaluate how co‐occurrence patterns among biological soil crusts (BSC)‐forming lichens changed along natural stress gradients driven by water and nutrient (N, P, K) availability. According to the SGH, we tested the hypothesis that the fine‐scale spatial arrangement of BSC‐forming lichens should shift from prevailing interspecific segregation to aggregation as abiotic stress increases. Co‐occurrence patterns ranged from significant species segregation to aggregation at the two spatial scales studied. When using the 5×5 cm grid, more plots showed significant species segregation than aggregation. At this sampling scale, co‐occurrence increased as water and nutrient availability decreased and increased, respectively. Small increases in soil pH promoted species co‐occurrence. Interspecific segregation was promoted as the cover of highly competitive species, such as Diploschistes diacapsis, increased. No significant relationships between co‐occurrence and the surrogates of abiotic stress were observed when data was arranged in a 10×10 cm grid. Our co‐occurrence analyses partially supported predictions from the SGH, albeit the results obtained were dependent on the type of abiotic stress and the spatial scale considered. They show the difficulties of predicting how co‐occurrence patterns change along complex stress gradients, and highlight the need of incorporating the effects of abiotic stress promoted by different resources, such as water and nutrients, into the conceptual framework of the SGH.
In defence of writing: a social semiotic perspective on digital media, literacy and learning
Authors: Skaar Håvard
Published: March 2009

From a learning perspective, social semiotics researchers tend to focus on the liberation latent in the multimedia options available through the new media. It is true that digital media democratise the possibilities open to the general public of a more varied and comprehensive text production than ever before, both in and outside school. Participating in this text production naturally implies a richer potential for learning. But digital technology also allows us to opt out of, and thus avoid, semiotic work. With this as the starting point, the present article sets out to highlight the pedagogical benefits associated with the written mode, precisely in an age when the digital media are making multimodal forms of expression increasingly available to us all.
Using inclusion, high demands and high expectations to resist the deficit syndrome: a study of eight Grade three classes overachieving in reading
Authors: Damber Ulla
Published: March 2009

The main objective of this study was to explore how teachers and classroom factors contribute to students' successful literacy learning. Eight Grade three classes, achieving at higher levels than expected with regard to socio‐economic background and language factors, were identified in a multicultural Stockholm district and statistically described. In‐depth interviews were performed to add the teachers' voices in order to get fuller descriptions of classroom life about literature‐based work and the creation of an inclusive classroom climate. The teachers' narratives illustrate how resistance to the deficit syndrome and avoidance of colour blindness were enacted in the classrooms and contributed to create positive conditions for literacy learning. The results indicated inclusion, high demands and high expectations as key concepts depicting these classrooms. The findings are discussed in relation to Vygotsky's theories, Bernstein's code theory, and critical language theory.
Properties of Porous Si3N4/BN Composites Fabricated by RBSN Technique
Authors: Liu Ji‐Xuan , Yuan Bo , Zhang Guo‐Jun , Kan Yan‐Mei , Wang Pei‐Ling
Published: March 2009

Reaction bonding of silicon nitride (RBSN) technique combined with slip‐casting shaping process was used to fabricate porous Si3N4/BN ceramic composites. Si/BN slurry with chemical stability, good dispersibility, and viscosity was prepared using glycerol trioleate (GTO) covering on Si surface and poly(acrylic acid) (PAA) as dispersant. The hydrolysis of Si was strongly prevented by GTO coating. The dispersibility of covered Si and BN suspensions were improved by PAA dispersant. Twenty volume percent covered Si/BN slurries with low viscosity were successfully casted. The cast bodies were dried at room temperature, debindered at 750°C and nitrided below 1450°C. The nitrided samples mainly consist of α‐Si3N4, β‐Si3N4, and h‐BN. The composites exhibit homogeneous microstructure consisting of faceted particles, α‐Si3N4 nanowires and a large amount of pores. The porosity is 52.64% and the pore size is in the range of 60–300 nm. The composites show compressive strength of 16.6±1.5 MPa. The dielectric constant of the composite is about 3.1 and the dielectric loss is below 0.5% under different frequencies.
Nondestructive Evaluation (NDE) for Characterizing Oxidation Damage in Cracked Reinforced Carbon–Carbon
Authors: Roth Don J. , Jacobson Nathan S. , Rauser Richard W. , Wincheski Russell A. , Walker James L. , Cosgriff Laura A.
Published: March 2009

In this study, coated reinforced carbon–carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter's thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using nondestructive evaluation (NDE) methods. These specimens were heat treated in air at 1143°C and 1200°C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3 mm. Single‐sided NDE methods were used because they might be practical for on‐wing inspection, while X‐ray micro‐computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon–carbon materials. An RCC sample having a naturally cracked coating and subsequent oxidation damage was also studied with X‐ray micro‐CT. This effort is a follow‐on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating.
Ambulatory or Home Measurement of Blood Pressure?
Authors: Gosse Philippe , Coulon Paul
Published: March 2009

Ambulatory blood pressure monitoring (ABPM) and home blood pressure (HBPM) monitoring have been shown to be superior to conventional measurement of blood pressure in terms of reproducibility, relationship to the impact of high blood pressure on target organs, and the prediction of cardiovascular events. Nevertheless, these 2 techniques have yet to find their place in the diagnosis of hypertension and during evaluation of the efficacy of antihypertensive treatment. Although these 2 methods do not give identical results in approximately 20% of cases, their diagnostic performance and prognostic value are quite comparable. Although ABPM remains a valuable tool in clinical research, its utilization in routine clinical practice is limited by cost and availability. HBPM is increasingly employed for informed and well‐managed patients, and it can help to improve control of the patient’s blood pressure. Physicians involved in the management of hypertensive patients should be aware of its value in order to assist patients in their care.
Floods in Tabasco, Mexico: a diagnosis and proposal for courses of action
Authors: Aparicio J. , Martínez‐Austria P.F. , Güitrón A. , Ramírez A.I.
Published: March 2009

From 28 to 30 October 2007, exceptional rainfall fell in the Grijalva River Basin, in Chiapas and Tabasco, Mexico, producing huge runoff and flooding in about 70% of the Tabasco flatlands. More than 1 million people were affected, mostly in the city of Villahermosa. In southeastern Mexico, flooding damages have increased in the last decades, due to population growth and human settlements developing in areas prone to flooding. A preliminary analysis is made of the causes of the disaster and of the possible courses of action that could be taken to prevent similar situations in the future. The hydrometeorological occurrence of the phenomenon is reviewed, and the operation and management of dams and other flood control system components, including forecast and alert procedures, are assessed. Recommendations are made on integrated flood management, joint operational policies of infrastructure, a territorial ordinance plan, forecast needs, social participation, training, and information dissemination among the population and stakeholders.
A panel of microsatellite loci from two species of octopus, Pareledone turqueti (Joubin, 1905) and Pareledone charcoti (Joubin, 1905)
Authors: STRUGNELL JAN M. , ALLCOCK A. LOUISE , WATTS PHILLIP C.
Published: March 2009

Eighteen dinucleotide microsatellite loci were isolated from two octopus species, Pareledone turqueti and Pareledone charcoti, which are endemic to the Southern Ocean. Genetic diversity was assessed in samples of P. charcoti and P. turqueti from Elephant Island and Shag Rocks respectively. All except one locus (which has proved to be polymorphic in other species) were variable in the focal species and amplified between six and 30 and between four and 28 alleles for P. charcoti and P. turqueti respectively; mean expected heterozygosities varied between 0.38 and 0.95 (P. charcoti) and between 0.34 and 0.97 (P. turqueti), with significant (P < 0.05) departures from Hardy–Weinberg equilibrium at seven loci; three of these loci provided significant (P < 0.05) evidence for null alleles. Two pairs of loci isolated from P. turqueti demonstrated significant (P < 0.05) linkage disequilibrium. We are presently using these genetic markers to quantify spatial genetic structure in the genus Pareledone.
Characterization of Mauritius parakeet (Psittacula eques) microsatellite loci and their cross‐utility in other parrots (Psittacidae, Aves)
Authors: RAISIN CLAIRE , DAWSON DEBORAH A. , GREENWOOD ANDREW G. , JONES CARL G. , GROOMBRIDGE JIM J.
Published: March 2009

We characterized 21 polymorphic microsatellite loci in the endangered Mauritius parakeet (Psittacula eques). Loci were isolated from a Mauritius parakeet genomic library that had been enriched separately for eight different repeat motifs. Loci were characterized in up to 43 putatively unrelated Mauritius parakeets from a single population inhabiting the Black River Gorges National Park, Mauritius. Each locus displayed between three and nine alleles, with the observed heterozygosity ranging between 0.39 and 0.96. All loci were tested in 10 other parrot species. Despite testing few individuals, between seven and 21 loci were polymorphic in each of seven species tested.
Selaginella bifida sp. nov. (Selaginellaceae: Pteridophyta) from Rodrigues Island, Mauritius
Authors: Delmail David
Published: March 2009

Selaginella bifida D. Delmail, a new species of the Selaginellaceae from Rodrigues Island, (Mascarene archipelago, Mauritius) is described and illustrated. The new species is related to S. rodrigueziana Baker in phenotypic appearance, but differs by having ciliate lateral leaf margins and bifid microsporophyll apices.
Mapping of direction and muscle representation in the human primary motor cortex controlling thumb movements
Authors: Z’Graggen W. J. , Conforto A. B. , Wiest R. , Remonda L. , Hess C. W. , Kaelin‐Lang A.
Published: March 2009

Larger body parts are somatotopically represented in the primary motor cortex (M1), while smaller body parts, such as the fingers, have partially overlapping representations. The principles that govern the overlapping organization of M1 remain unclear. We used transcranial magnetic stimulation (TMS) to examine the cortical encoding of thumb movements in M1 of healthy humans. We performed M1 mapping of the probability of inducing a thumb movement in a particular direction and used low intensity TMS to disturb a voluntary thumb movement in the same direction during a reaction time task. With both techniques we found spatially segregated representations of the direction of TMS‐induced thumb movements, thumb flexion and extension being best separated. Furthermore, the cortical regions corresponding to activation of a thumb muscle differ, depending on whether the muscle functions as agonist or as antagonist for flexion or extension. In addition, we found in the reaction time experiment that the direction of a movement is processed in M1 before the muscles participating in it are activated. It thus appears that one of the organizing principles for the human corticospinal motor system is based on a spatially segregated representation of movement directions and that the representation of individual somatic structures, such as the hand muscles, overlap.
Optimal Path Planning for Robotic Insertion of Steerable Electrode Arrays in Cochlear Implant Surgery
Authors: Zhang Jian , Roland J. Thomas , Manolidis Spiros , Simaan Nabil
Published: March 2009

This paper presents an optimal path planning method of steerable electrode arrays for robot-assisted cochlear implant surgery. In this paper, the authors present a novel design of steerable electrode arrays that can actively bend at the tip. An embedded strand in the electrode array provides an active steering degrees-of-freedom (DoF). This paper addresses the calibration of the steerable electrode array and the optimal path planning for inserting it into planar and three-dimensional scala tympani models. The goal of the path planning is to minimize the intracochlear forces that the electrode array applies on the walls of the scala tympani during insertion. This problem is solved by designing insertion path planning algorithms that provide best fit between the shape of the electrode array and the curved scala tympani during insertion. Optimality measures that account for shape discrepancies between the steerable electrode array and the scala tympani are used to solve for the optimal path planning of the robot. Different arrangements of DoF and insertion speed force feedback (ISFF) are simulated and experimentally validated in this paper. A quality of insertion metric describing the gap between the steerable electrode array and the scala tympani model is presented and its correspondence to the insertion force is shown. The results of using 1DoF, 2DoF, and 4DoF electrode array insertion setups are compared. The 1DoF insertion setup uses nonsteerable electrode arrays. The 2DoF insertion setup uses single axis insertion with steerable electrode arrays. The 4DoF insertion setup allows full control of the insertion depth and the approach angle of the electrode with respect to the cochlea while using steerable electrode arrays. It is shown that using steerable electrode arrays significantly reduces the maximal insertion force (59.6% or more) and effectively prevents buckling of the electrode array. The 4DoF insertion setup further reduces the maximal electrode insertion forces. The results of using ISFF for steerable electrodes show a slight decrease in the insertion forces in contrast to a slight increase for nonsteerable electrodes. These results show that further research is required in order to determine the optimal ISFF control law and its effectiveness in reducing electrode insertion forces.
A Scaling Parameter for Predicting Pressure Wave Reflection in Stented Arteries
Authors: Charonko John J. , Ragab Saad A. , Vlachos Pavlos P.
Published: March 2009

A one-dimensional finite-difference model was developed to predict pressure wave reflections in stented arteries, and a parametric study of variations in stent and vessel properties was performed, including stent stiffness, length, and compliance transition region, as well as vessel radius and wall thickness. The model was solved using a combination of weighted essentially nonoscillatory and Runge–Kutta methods. Over 100 cases were tested and the magnitudes of the predicted waves were less than 0.5 mm Hg for all cases, less than 1% of the normal pulse pressure of 40 mm Hg. It was also shown that reasonable variations in these parameters could induce changes in reflection magnitude of up to ±50%. The relationship between each of these properties and the resulting wave reflection could be described in a simple manner, and the effect of all of them together could, in fact, be encompassed by a single nondimensional parameter titled “stent authority.” It is believed that stent authority is a novel way of relating the energy imposed upon the arterial wall by the stent to the fraction of the incident pressure energy that is reflected from the stented region. Based on these results, it is believed that stent design can have a significant effect on pressure wave reflections; however, it was concluded that their small magnitudes make clinical relevance of these waves unlikely, regardless of design.
Prevention of Death in Bacterium-Infected Mice by a Synthetic Antimicrobial Peptide, L5, through Activation of Host Immunity
Authors: Okuyama-Nishida Yukiko , Akiyama Nobuko , Sugimori Giichi , Nomura Kazuhide , Ogawa Kenji , Homma Koichi J. , Sekimizu Kazuhisa , Tsujimoto Masafumi , Natori Shunji
Published: March 2009

In our previous study, we found that the antibacterial peptide KLKLLLLLKLK-NH2(L5) and itsd-enantiomer (DL5) activate neutrophils to produce superoxide anions (O2−) and prevent death due to infection by methicillin-resistantStaphylococcus aureus, suggesting that these peptides may elicit in vivo antimicrobial activities through host inflammatory responses mediated by neutrophils. In this study, we investigated the mechanisms behind in vivo antimicrobial prophylaxis by the use of L5 for the treatment of bacterial infection introduced via intra-abdominal implantation. We found that the intraperitoneal treatment with L5 before bacterial infection markedly reduced rates of death due to infection. Treatments with L5 were highly effective in preventing death due to intraperitoneal inoculation of not onlyS. aureusSmith but alsoEnterococcus faecalisSR1004 andEscherichia coliEC14. The intra-abdominal administration of L5 induced accumulation of neutrophils, increased levels of reactive oxygen species, and augmented antibacterial activity in the abdominal cavity. In addition, administration of L5 upregulated the expression of theMig/CXCL9chemokine gene in thioglycolate-elicited peritoneal macrophages. Our results suggested that the prevention of death by treatment of infected mice with L5 might occur primarily through the activation of a host immune response.