bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitat degradation, topography and rainfall variability interact to determine seed distribution and recruitment in a sand dune grassland
Authors: Li Feng‐Rui , Zhao Li‐Ya , Zhang Hua , Liu Ji‐Liang , Lu Hai‐Yan , Kang Ling‐Fen
Published: July 2009

Question: Understanding the mechanisms underlying how habitat degradation, topography and rainfall variability interactively affect seed distribution and seedling recruitment is crucial for explaining plant community patterns and dynamics. Interactions between these major factors were studied together in a semiarid sand dune grassland.

Location: Eastern Inner Mongolia, China.

Methods: The study system used four sites of fixed, semifixed, semishifting and shifting sand dune grasslands, representing a gradient of habitat degradation. We investigated the density of germinable seeds deposited in the top 5 cm of soil and in situ seedling emergence (number of seedlings emerging early in the growing season) and establishment (number of plants recruited at the end of the growing season) at three topographic positions (dune top, windward and leeward sides) within each site over 2 years that differed in rainfall. Habitat characteristics (i.e. vegetation cover, plant species composition and diversity, soil moisture and nutrient availability and soil erodibility) of the four sites were also measured.

Results: Habitat degradation (i.e. decreased vegetation cover and enhanced wind erosion rate) significantly reduced the size of the germinable soil seed bank. On average, germinable seed number from the high‐vegetation cover fixed dune was 36‐fold larger than the low‐vegetation cover shifting dune, and eight‐ and two‐fold larger, respectively, than the semishifting and semifixed dunes with intermediate vegetation cover. We observed within‐habitat variability in seed distribution, but among‐topographic position variation differed among habitats. Seedling recruitment showed large between‐year, and among‐ and within‐habitat variability, but these variations varied significantly depending on the response variables evaluated (i.e. initial seedling density, final plant density, emergence rate and recruitment rate). Path analysis revealed complex density‐dependent positive and negative, direct and indirect effects of germinable seed density and initial seedling density on recruitment, but the relative importance of these density‐dependent effects varied depending on habitat type and rainfall availability.

Conclusion: Our results suggest that habitat degradation, microtopography and rainfall availability interact in shaping sand dune seed bank and plant community recruitment patterns and dynamics. Their effects were mainly mediated through changes in both the biotic and abiotic environment during the process of habitat deterioration.
Progression of Lipid Peroxidation Measured as Thiobarbituric Acid Reactive Substances, Damage to DNA and Histopathological Changes in the Liver of Rats Subjected to a Methionine–Choline‐Deficient Diet
Authors: Jordao Alceu Afonso , Zanutto Marcia Elena , Domenici Fernanda Aparecida , Portari Guilherme Vannucchi , Cecchi Andréa Oliveira , Zucoloto Sergio , Vannucchi Helio
Published: July 2009

Abstract:  Methionine–choline‐deficient diet represents a model for the study of the pathogenesis of steatohepatitis. Male rats were divided into three groups, the first group receiving a control diet and the other two groups receiving a methionine–choline‐deficient diet for 1 month (MCD1) and for 2 months (MCD2), respectively. The livers of the animals were collected for the determination of vitamin E, thiobarbituric acid reactive substances (TBARS), GSH concentration, DNA damages, and for histopathological evaluation. The hepatic TBARS and GSH content was higher (P < 0.05) in the groups receiving the experimental diet (MCD1 and MCD2) compared to control diet, and hepatic vitamin E concentration differed (P < 0.05) between the MCD1 and MCD2 groups, with the MCD2 group presenting a lower concentration. Damage to hepatocyte DNA was greater (P < 0.05) in the MCD2 group (262.80 DNA injuries/100 hepatocytes) compared to MCD1 (136.4 DNA injuries/100 hepatocytes) and control diet (115.83 DNA injuries/100 hepatocytes). Liver histopathological evaluation showed that steatosis, present in experimental groups was micro‐ and macro‐vesicular and concentrated around the centrolobular vein, zone 3, with preservation of the portal space. The inflammatory infiltrate was predominantly periductal and the steatosis and inflammatory infiltrate was similar in the MCD1 and MCD2 groups, although the presence of Mallory bodies was greater in the MCD2 group. The study describes the contribution of a methionine–choline‐deficient diet to the progression of steatosis, lipid peroxidation and hepatic DNA damage in rats, serving as a point of reflection about the role of these nutrients in the western diet and the elevated non‐alcoholic steatohepatitis rates in humans.
Evaluation of Temporal Artery Thermometry in Children 3–36 Months Old
Authors: Holzhauer Janet K. , Reith Vicky , Sawin Kathleen J. , Yen Kenneth
Published: July 2009

PURPOSE.  This study aims to determine whether temporal artery (TA) thermometer readings are accurate and better tolerated than rectal readings in young children.

DESIGN AND METHODS.  Paired rectal and TA temperature readings and Face Legs Activity Cry and Consolability (FLACC) scores were obtained.

RESULTS.  TA thermometry failed to detect rectal fever (38°C or greater) in approximately 20% of paired temperature readings. FLACC scores were significantly lower after TA readings than after rectal readings.

PRACTICE IMPLICATIONS.  This study questions TA readings as an accurate substitute for rectal thermometry.
Fat uptake, shelf stability and sensory quality of rice crackers produced using soy and selected additives
Authors: Puyed Surekha S. , Prakash Jamuna
Published: July 2009

The effects of incorporating soy flour (at 20% level) and additives on fat uptake, shelf stability and keeping quality of a traditional deep‐fried snack prepared with rice and black gram was studied. The additives used for experimental products were citric acid (0.5%), pectin (0.5%) and potassium sulphate (1.0%) along with soy flour. Incorporation of soy decreased fat absorption to a significant extent in the products (22.6% as against 28.2% in control). This effect was further enhanced with pectin. Free fatty acids and peroxide values increased on storage gradually. However, the increase was lesser in products with soy. Products stored in metallized foil were better than the products stored in low density polyethylene. All the products were acceptable throughout the storage period. Incorporation of soy and potassium sulphate resulted in reduced fat uptake and improved sensory and keeping quality of product.
Differences in health status of older people aged 65 and above after total hip replacement compared with the normal population: a cross‐sectional study
Authors: Hørdam Britta , Søballe Kjeld , Pedersen Preben U.
Published: July 2009

Aim.  The aim of the study was to describe the health status of older patients with osteoarthrosis following total hip replacement and to compare their health status with population norms in order to analyse the need for a rehabilitation programme after total hip replacement.

Background.  Total hip replacement is a very efficient operation in terms of pain relief and improvement of walking ability. However, after the operation some patients still report low health status.

Method.  A cross‐sectional study including 287 older patients aged 65–74 and 75+ years who had had total hip replacement within the previous 12 months was performed. Patients from five Danish counties received a mailed questionnaire requesting information about their health status and demographic data. The Short‐Form 36 measures eight domains of importance of health. The scores related to each dimension are transformed to an interval scale ranging from 0 (worst score) to 100 (best score). Danish population norm data were used as reference point.

Results.  In total, 287 (91.4%) patients responded. The patients completed the questionnaire 207 (114) days after surgery within a range of 10–360 days. In all eight health domains patients reported significantly lower scores than the age specific norm population.

Conclusion.  Our results indicate that health status is scored lower for patients after total hip replacement. This implies that there might be a need for further postoperative rehabilitation based on the identification of problems experienced by patients in the postoperative period.

Relevance to clinical practice.  Patients health status is a predictor for well‐being, quality of life and survival. Older people need rehabilitation after surgery to reduce dysfunction and improve perception of health. Our results demonstrate a need for further studies examining problems experienced by patients in the postoperative period. Intervention research is needed before such a programme can be implemented.
Staying in ‘the stream of life’: rehabilitation of older people in their own homes following total hip replacement
Authors: Delmar Charlotte , Rasmussen Birgitte , Dolmer Ilone
Published: July 2009

Background.  According to World Health Organization (WHO), rehabilitation should be based on the person’s entire situation with a focus on body functions, level of activity, participation and environment. But different types of investigations show an unclear concept of rehabilitation in professional nursing.

Aims and objectives.  This study aims to identify older persons’ (≥75 years of age) experiences of the rehabilitation process after total hip replacement.

Design and methods.  Qualitative interviews were undertaken with six persons who were rehabilitated in their own homes following total hip replacement. The interviews were guided by Max van Manen’s phenomenological methodology with its focus on the life world as described through patients’ experience of time, space, body and interpersonal relations.

Results.  Staying in the stream of life confirmed the importance of the life world. What is essential in the rehabilitation process is to get back into everyday life as soon as possible and participate in activities which are meaningful and which are linked to being at home where ‘you can be who you are’. The home is the framework for being in the stream of life, and it provides the centre of gravity for the people’s welfare.

Conclusion.  Staying in the stream of life is about being the author of one’s own meaningful life. It takes into account life phenomena embodied in the maintenance aspect of health care; dignity in relation to identity and integrity; and an understanding of the dialectical relation between frailty and strength.

Relevance to clinical practice.  Rather than focusing exclusively on patient participation and goal‐directed activity, nursing actions should integrate life phenomena as key aspects of rehabilitation with older people in their own right.
Anti‐polymorphonuclear neutrophil antibodies in patients with leukopenia or neutropenia
Authors: RIERA N. E. , ROSSO SALTÓ M. , GALÁN V. , CANALEJO K. , KHOURY M. , AIXALÁ M. , KANTOR G. L. , VERMEULEN M. , BENGIÓ R. , DE BRACCO M. M. E.
Published: July 2009

Introduction:  Immune humoral neutropenia (Np) could be the consequence of anti‐polymorphonuclear neutrophil (PMN) antibodies, circulating immune complexes (CIC) and/or antibodies against myeloid precursors. Granulocyte immunofluorescence test (GIFT) and a leukoagglutination technique (LAGT) assays are recommended for its diagnosis.

Methods:  Fifty adult patients with secondary Np were screened for anti‐PMN. GIFT by flow cytometry from viable PMN and LAGT were employed. In addition, CIC levels, low expression of CD16b (CD16 blow), PMN phenotype and sera tumor necrosis factor‐alpha (TNF‐α) were also evaluated.

Results:  Direct IgG‐PMN binding (dir‐GIFT) was positive in 16% of the patients. Antibodies against autologous PMN were detected in 32% of the samples by indirect (ind)‐GIFT and demonstrated in 70% of the sera by both ind‐GIFT and/or LAGT. Predominance of human neutrophil alloantigen (HNA)‐1b and HNA‐2 expression was confirmed. CD16blow was detected in 16% of the patient’s PMN and TNF‐α in 68% of sera patients.

Conclusion:  Our results suggest that diagnosis of immune Np in the laboratory may be improved by focusing on patient’s PMN together with the assessment of cellular markers.
Pooled samples bias fungal community descriptions
Authors: AVIS P. G. , BRANCO S. , TANG Y. , MUELLER G. M.
Published: July 2009

We tested the accuracy of molecular analyses for recovering the species richness and structure of pooled fungal communities of known composition. We constructed replicate pools of 2–20 species and analysed these pools by two separate pooling‐DNA extraction procedures and three different molecular analyses (Automated Ribosomal Intergenic Spacer Analysis (ARISA), terminal restriction fragment length polymorphism (T‐RFLP) and clone library‐sequencing). None of the methods correctly described the known communities. Only clone library‐sequencing with high sequencing per pool (∼100 clones) recovered reasonable estimates of richness. Frequency data were skewed with all procedures and analyses. These results indicate that the error introduced by pooling samples is significant and problematic for ecological studies of fungal communities.
Myopia and later physical activity in adolescence: a prospective study: Table 1
Authors: Deere K , Williams C , Leary S , Mattocks C , Ness A , Blair S N , Riddoch C
Published: July 2009

Objectives:

To investigate associations between objectively measured physical activity (PA) and myopia in children.

Methods:

Children from the Avon Longitudinal Study of Parents and Children (ALSPAC) were asked to wear a uniaxial accelerometer for 7 days. Measures of counts per minute (cpm), minutes spent in moderate to vigorous activity (MVPA) and minutes of sedentary behaviour (msed) were derived from the accelerometer worn at age 12. Children were also examined, at age 10, using an autorefractor to estimate myopia. Social and parental factors were collected from pregnancy and physical measures of the child were recorded at age 12.

Results:

4880 children had valid PA and autorefraction data. In minimally adjusted models (age and gender) myopic children were less active than the other children: β = −49.9 cpm (95% CI −73.5 to −26.4, p = <0.001). The myopic group spent less time in MVPA than the other children: β = −3.2 minutes MVPA (95% CI −5.2 to −1.1, p = 0.003) and more time sedentary: β = 15.8 minutes (95% CI 5.8 to 25.8, p = 0.002). The effect sizes were attenuated by adjustment for social and behavioural confounders although myopia status in the better (less myopic on autorefraction) eye remained strongly associated with cpm and MVPA but less so for sedentary behaviour: β = −36.8 cpm (95% CI –67.8 to −5.8, p = 0.02), β = −2.7 MVPA (95% CI −5.3 to −0.1, p = 0.04), β = 10.1 msed (95% CI –2.9 to 23.1, p = 0.13).

Conclusion:

Myopic children may be more at risk of having lower levels of PA than their non-myopic peers, although the difference was modest.
Ankylosing spondylitis in sub-Saharan Africa
Authors: Belachew D A , Sandu N , Schaller B , Guta Z
Published: July 2009

Ankylosing spondylitis (AS) represents a chronic inflammatory bone disease of the axial skeleton that manifests as chronic back pain and progressive stiffness of the spine. It characteristically affects young adults with a peak age of onset between 20–30 years. In contrast to Western Europe and North America, the disease is rare in Sub-Saharan Africa where the majority of the population is HLA-B27 negative. Even in some African populations where HLA-B27 is prevalent (for example, in Gambia and Senegal, where 3–6% of the general population has HLA-B27), the disease is also said to be rare. However, some other genetic markers may be involved in the causation of AS in the HLA-B27 negative population, and when it occurs in this subgroup of patients it has a similar manifestation with HLA-B27 negative white patients and these patients rarely develop anterior uveitis. The clinical presentation of the disease in Africa is generally milder; most affected individuals do not have a family history of AS, the patients are older at onset of the disease, and the majority of them lack extra-articular manifestations such as anterior uveitis compared with the situation in Western Europe and North America. In conclusion, AS in sub-Saharan Africa seems to represent a subgroup of the disease, which may open the window to a greater understanding of the pathophysiology of the condition.
Do radiologists still need to report chest x rays?
Authors: Mehrotra P , Bosemani V , Cox J
Published: July 2009

Objective

Chest x rays (CXRs) are among the most difficult radiographs to interpret accurately. The aim of this study was to assess the ability of different grades and specialities of clinicians to evaluate a series of CXRs correctly.

Methods

60 clinicians of different grades and from different specialities were randomly recruited to interpret 15 CXRs within 30 min. Radiographs included normal (n = 5) and abnormal images of common medical emergencies (n = 10). Non-parametric statistical tests examined for significant differences in the ability of different grades and specialities of doctors to interpret CXRs.

Results

Senior doctors (consultants and registrars, n = 32) attained significantly higher scores than junior doctors (senior house officers, foundation 1 and 2 doctors, n = 28, p = 0.001). Specialists (consultants and registrars in radiology and respiratory medicine, n = 7) achieved significantly higher scores than non-specialists (all other consultants and registrars, n = 25, p = 0.0002). In addition, senior radiologists (consultants and registrars) attained significantly higher scores than senior doctors from other specialities (p = 0.002).

Conclusion

To improve patient care, we suggest that all chest x rays should be reviewed at an early stage during a patient’s hospital admission by a senior clinician and reported by a radiologist at the earliest opportunity. We also suggest that structured teaching on CXR interpretation should be made available for newly qualified doctors, especially with the introduction of shortened training.
Concurrent outbreaks of Chikungunya and Dengue fever in Kandy, Sri Lanka, 2006–07: a comparative analysis of clinical and laboratory features
Authors: Kularatne S A M , Gihan M C , Weerasinghe S C , Gunasena S
Published: July 2009

Objectives

To compare the clinical and laboratory features of confirmed cases of Chikungunya and Dengue fever; to validate the clinical diagnosis based on serology.

Methods

Cases with a clinical diagnosis of Chikungunya and Dengue fever were recruited for seroconfirmation during a concurrent epidemic in 2006–07, at the General Hospital, Peradeniya, Sri Lanka.

Results

Of 54 patients with fever, serology confirmed 21 with Chikungunya infection, 20 with Dengue infection, and three co-infections, with sensitivity of the clinical diagnosis of 92% for Chikungunya fever and 95% for Dengue fever. The mean age of patients with Chikungunya fever was 45 years (range 21–74 years), and patients with Dengue fever was 30 years (range 15–63 years) (p = 0.005). Sixteen (70%) of Chikungunya fever patients were females, while 15 (71%) of those with Dengue fever were males (p = 0.007). Arthralgia was common to both groups (p = 0.155), while headache and a bleeding tendency were observed more in patients with Dengue fever. Twelve (57%) Chikungunya cases had acute arthritis compared with none in the Dengue group (p = 0.001), lasting mean 6 days (range 1–14 days). They developed chronic arthritic disability (range 1–6 months). Leucopenia was common to both Chikungunya and Dengue fever patients. However, thrombocytopenia was more pronounced in the Dengue patients (mean (SD) platelet count 75 (34)×109/l) than in the Chikungunya patients (117 (70)×109/l) (p = 0.001). In the Chikungunya group there was a positive correlation between duration of the illness and the platelet count (r = 0.181, p = 0.194), but the Dengue group showed a negative correlation (r = −0.309, p<0.001).

Conclusion

Most of the clinical and laboratory features of patients with Chikungunya and Dengue fever are similar. Arthritis is the pathgnomonic sign in patients with Chikungunya fever.
Diagnosis and treatment of acquired coronary artery disease in adults
Authors: Wilson J M
Published: July 2009

Coronary artery disease evolves, often unnoticed, over decades, often culminating in myocardial infarction. Metabolic and behavioural risk factors affect the development and progression of atherosclerotic lesions. The diagnosis may be arrived at clinically but typically involves confirmatory and prognostic laboratory tests and imaging studies. Treatment measures are aimed at controlling symptoms and preventing disease progression. In patients with clinically stable disease, treatment centres upon preventing disease progression using lifestyle modification, medical therapy and revascularisation for patients in whom medical treatment failure may be imminently fatal. In patients with acute coronary syndrome, urgent treatment is required in order to arrest lesion progression.
Management of the dialysis patient for the hospital physician
Authors: Power A , Duncan N , Goodlad C
Published: July 2009

As a relative shortage of organs limits transplantation rates in many countries, the number of patients on dialysis is increasing. Nephrologists in specialist centres supervise their dialysis, but increasingly in the context of acute medical emergencies, such patients present to district general hospitals. Experience in managing patients on dialysis varies among institutions. This review aims to provide a practical guide to aid general physicians involved in the delivery of hospital care, by outlining the principles of dialysis (haemodialysis and peritoneal dialysis) and examining relevant medical issues specific to dialysis patients.
Congenital and acquired conditions of the aortic root: multidetector computed tomography features
Authors: Vargas H A , Hoey E T D , Gopalan D , Agrawal S K B , Screaton N J , Gulati G S
Published: July 2009

The aortic root links the left ventricle and ascending aorta and functions as a support structure for the aortic valve. It can be affected by a variety of congenital and acquired conditions, some of which are potentially life threatening. Echocardiography and cardiac magnetic resonance imaging are established non-invasive imaging techniques for assessing the aortic root. Recent technological advances have allowed multidetector computed tomography to emerge as an alternative means of assessing this aortic segment. This pictorial essay reviews the anatomy of the aortic root and illustrates the salient computed tomography imaging features of a range of congenital and acquired conditions that may affect it.
PARAFERMIONS, PARABOSONS AND REPRESENTATIONS OF 𝔰𝔬(∞) AND 𝔬𝔰𝔭(1|∞)
Authors: STOILOVA N. I. , VAN DER JEUGT J.
Published: July 2009

The goal of this paper is to give an explicit construction of the Fock spaces of the parafermion and the paraboson algebra, for an infinite set of generators. This is equivalent to constructing certain unitary irreducible lowest weight representations of the (infinite rank) Lie algebra 𝔰𝔬(∞) and of the Lie superalgebra 𝔬𝔰𝔭(1|∞). A complete solution to the problem is presented, in which the Fock spaces have basis vectors labelled by certain infinite but stable Gelfand–Zetlin patterns, and the transformation of the basis is given explicitly. We also present expressions for the character of the Fock space representations.
THE COHOMOLOGICAL CREPANT RESOLUTION CONJECTURE FOR ℙ(1,3,4,4)
Authors: BOISSIÈRE S. , MANN E. , PERRONI F.
Published: July 2009

We prove the cohomological crepant resolution conjecture of Ruan for the weighted projective space ℙ(1,3,4,4). To compute the quantum corrected cohomology ring, we combine the results of Coates–Corti–Iritani–Tseng on ℙ(1,1,1,3) and our previous results.
COMPLEXITY OF VILLAMAYOR'S ALGORITHM IN THE NON-EXCEPTIONAL MONOMIAL CASE
Authors: BLANCO R.
Published: July 2009

We study monomial ideals, always locally given by a monomial, like a reasonable first step to estimate in general the number of monoidal transformations of Villamayor's algorithm of resolution of singularities. The resolution of a monomial ideal [Formula: see text] is interesting due to its identification with the particular toric problem [Formula: see text].

In the special case, when all the exponents aiare greater than or equal to the critical value c, we construct the largest branch of the resolution tree which provides an upper bound involving partial sums of Catalan numbers. This case will be called "minimal codimensional case". Partial sums of Catalan numbers (starting 1,2,5,…) are 1,3,8,22,…. These partial sums are well known in Combinatorics and count the number of paths starting from the root in all ordered trees with n + 1 edges. Catalan numbers appear in many combinatorial problems, counting the number of ways to insert n pairs of parenthesis in a word of n + 1 letters, plane trees with n + 1 vertices,…, etc.

The non-minimal case, when there exists some exponent ai0smaller than c, will be called "case of higher codimension". In this case, still unresolved, we give an example to state the foremost troubles.

Computation of examples has been helpful in both cases to study the behavior of the resolution invariant. Computations have been made in Singular (see [8]) using the desing package by Bodnár and Schicho, see [4].
UNIQUENESS THEOREM OF MEROMORPHIC MAPPINGS INTO ℙN (ℂ) SHARING 2N + 3 HYPERPLANES REGARDLESS OF MULTIPLICITIES
Authors: CHEN ZHIHUA , YAN QIMING
Published: July 2009

In this paper, we prove a uniqueness theorem of meromorphic mappings from ℂn into ℙN(ℂ) sharing 2N + 3 hyperplanes in ℙN(ℂ) located in general position without counting multiplicities.
MATRIX SUBADDITIVITY INEQUALITIES AND BLOCK-MATRICES
Authors: BOURIN JEAN-CHRISTOPHE
Published: July 2009

We give a number of subadditivity results and conjectures for symmetric norms, matrices and block-matrices. Let A, B, Z be matrices of same size and suppose that A, B are normal and Z is expansive, i.e. Z*Z ≥ I. We conjecture that [Formula: see text] for all non-negative concave function f on [0,∞) and all symmetric norms ‖ · ‖ (in particular for all Schatten p-norms). This would extend known results for positive operator to all normal operators. We prove these inequalities in several cases and we propose some related open questions, both in the positive and normal cases. As nice applications of subadditivity results we get some unusual estimates for partitioned matrices. For instance, for all symmetric norms and 0 ≤ p ≤ 1, [Formula: see text] whenever the partitioned matrix is Hermitian or its entries are normal. We conjecture that this estimate for f(t) = tp remains true for all non-negative concave functions f on the positive half-line. Some results for general block-matrices are also given.
REALIZATION OF MINIMAL C*-DYNAMICAL SYSTEMS IN TERMS OF CUNTZ–PIMSNER ALGEBRAS
Authors: LLEDÓ FERNANDO , VASSELLI EZIO
Published: July 2009

In the present article, we provide several constructions of C*-dynamical systems [Formula: see text] with a compact group [Formula: see text] in terms of Cuntz–Pimsner algebras. These systems have a minimal relative commutant of the fixed-point algebra [Formula: see text] in [Formula: see text], i.e. [Formula: see text], where [Formula: see text] is the center of [Formula: see text], which is assumed to be non-trivial. In addition, we show in our models that the group action [Formula: see text] has full spectrum, i.e. any unitary irreducible representation of [Formula: see text] is carried by a [Formula: see text]-invariant Hilbert space within [Formula: see text].

First, we give several constructions of minimal C*-dynamical systems in terms of a single Cuntz–Pimsner algebra [Formula: see text] associated to a suitable [Formula: see text]-bimodule ℌ. These examples are labelled by the action of a discrete Abelian group ℭ (which we call the chain group) on [Formula: see text] and by the choice of a suitable class of finite dimensional representations of [Formula: see text]. Second, we present a more elaborate contruction, where now the C*-algebra [Formula: see text] is generated by a family of Cuntz–Pimsner algebras. Here, the product of the elements in different algebras is twisted by the chain group action. We specify the various constructions of C*-dynamical systems for the group [Formula: see text], N ≥ 2.
Chameleon Coatings: Adaptive Surfaces to Reduce Friction and Wear in Extreme Environments
Authors: Muratore C. , Voevodin A.A.
Published: July 2009

Adaptive nanocomposite coating materials that automatically and reversibly adjust their surface composition and morphology via multiple mechanisms are a promising development for the reduction of friction and wear over broad ranges of ambient conditions encountered in aerospace applications, such as cycling of temperature and atmospheric composition. Materials selection for these composites is based on extensive study of interactions occurring between solid lubricants and their surroundings, especially with novel in situ surface characterization techniques used to identify adaptive behavior on size scales ranging from 10−10 to 10−4 m. Recent insights on operative solid-lubricant mechanisms and their dependency upon the ambient environment are reviewed as a basis for a discussion of the state of the art in solid-lubricant materials.
Materials for Optical Lithography Tool Application
Authors: Sewell Harry , Mulkens Jan
Published: July 2009

This review of materials development for optical lithography covers two areas: materials for optical steppers and scanners, and materials for EUV lithography. In the former, materials development for advanced immersion lenses and for high-index immersion lens is discussed, whereas in the latter, materials used in multilayer EUV mirrors and to generate EUV photons are discussed.
High-κ/Metal Gate Science and Technology
Authors: Guha Supratik , Narayanan Vijay
Published: July 2009

High-κ/metal gate technology is on the verge of replacing conventional oxynitride dielectrics in state-of-the-art transistors for both high-performance and low-power applications. In this review we discuss some of the key materials issues that complicated the introduction of high-κ dielectrics, including reduced electron mobility, oxygen-based thermal instabilities, and the absence of thermally stable dual-metal electrodes. We show that through a combination of materials innovations and engineering ingenuity these issues were successfully overcome, thereby paving the way for high-κ/metal gate implementation.
Nanoimprint Lithography Materials Development for Semiconductor Device Fabrication
Authors: Costner Elizabeth A. , Lin Michael W. , Jen Wei-Lun , Willson C. Grant
Published: July 2009

The term nanoimprint lithography (NIL) describes a number of processes used to form nanoscale structures by molding or embossing. Step and flash imprint lithography (S-FIL, a trademark of Molecular Imprints, Inc.) is a variant of NIL that can be performed at room temperature and low pressure. In S-FIL, a low-viscosity liquid imprint material is hardened in a patterned template by exposure to UV light. S-FIL is ideally suited to integrated-circuit device fabrication. Materials development for S-FIL has progressed significantly since its introduction in 1999. We discuss the status of materials development, with specific emphasis on the imprint material and functional materials, template fabrication and release layers, and S-FIL process variations.
Recent Progress in Theoretical Prediction, Preparation, and Characterization of Layered Ternary Transition-Metal Carbides
Authors: Wang Jingyang , Zhou Yanchun
Published: July 2009

Layered ternary carbides contain alternative stacking of structural slabs in the unit cells. Many mechanical and structural features are inherited with respect to their binary carbide counterparts, and some novel properties also appear because of new chemical bonds and atomic coordination at the boundaries of different slabs. In this review, we highlight important recent achievements that focus on theoretical prediction, microstructure characterization preparation, and macroscopic properties of newly developed layered ternary transition-metal carbides. These results provide insights into understanding the relationship between the structure (including crystal structure, chemical bonding, and microstructure) and the properties of these layered ternary carbides and further highlight their technological applications as high-temperature and ultrahigh-temperature structural materials.
Immersion Lithography: Photomask and Wafer-Level Materials
Authors: French Roger H. , Tran Hoang V.
Published: July 2009

Optical immersion lithography utilizes liquids with refractive indices >1 (the index of air) below the last lens element to enhance numerical aperture and resolution, enabling sub-40-nm feature patterning. This shift from conventional dry optical lithography introduces numerous challenges requiring innovations in materials at all imaging stack levels. In this article, we highlight the recent materials advances in photomasks, immersion fluids, topcoats, and photoresists. Some of the challenges encountered include the fluids' and photomask materials' UV durability, the high-index liquids' compatibility with topcoats and photoresists, and overall immersion imaging and defectivity performance. In addition, we include a section on novel materials and methods for double-patterning lithography—a technique that may further extend immersion technology by effectively doubling a less dense pattern's line density.
Materials for Magnetoresistive Random Access Memory
Authors: Slaughter J.M.
Published: July 2009

MRAM technology is based on the storage of data in stable magnetic states using devices that have a large magnetoresistance effect, so that the data can be read by determining the resistance of the device. MRAM is inherently nonvolatile and the magnetic states can be switched extremely fast and with no wear out. In this article, we review the fundamentals of MRAM technology, explain the innovations that have overcome barriers to commercialization, and describe areas where further innovation can advance the technology most significantly. The influence of key structural and magnetic properties of materials used in magnetic tunnel junctions, and optimization of those devices for read and write performance in memory arrays, is discussed in detail. The various approaches to writing data in MRAM arrays are described and compared, with emphasis on toggle MRAM, the type that is in commercial production, and on spin-torque MRAM, which shows great promise for future improvements in power and density. In the final section, we summarize recent demonstrations of advanced MRAM technology.
Molecular Electronics
Authors: Heath James R.
Published: July 2009

Molecular electronics describes the field in which molecules are utilized as the active (switching, sensing, etc.) or passive (current rectifiers, surface passivants) elements in electronic devices. This review focuses on experimental aspects of molecular electronics that researchers have elucidated over the past decade or so and that relate to the fabrication of molecular electronic devices in which the molecular components are readily distinguished within the electronic properties of the device. Materials, fabrication methods, and methods for characterizing electrode materials, molecular monolayers, and molecule/electrode interfaces are discussed. A particular focus is on devices in which the molecules or molecular monolayer are sandwiched between two immobile electrodes. Four specific examples of such devices, in which the electron transport characteristics reflect distinctly molecular properties, are discussed.
Phase Change Materials
Authors: Raoux Simone
Published: July 2009

Phase change materials (PCMs) can exist in at least two different phases (an amorphous and one or more crystalline phases), and they can be switched repeatedly between these phases. The different phases have distinctly different physical properties such as electrical conductivity, optical reflectivity, mass density, or thermal conductivity. These differences and the repeatability of the switching give these materials the ability to store information. Rewritable compact discs, digital versatile discs, and Blu-ray™ discs store information in thin films of PCMs, using the difference in reflectivity between the phases as the storage mechanism. A novel solid-state memory technology that applies the difference in electrical resistivity is currently being developed, and possible future applications include reconfigurable logic. This article reviews the unique set of properties of PCMs and their current and future applications.
Plasticity of Micrometer-Scale Single Crystals in Compression
Authors: Uchic Michael D. , Shade Paul A. , Dimiduk Dennis M.
Published: July 2009

This review examines the recent literature that has focused on uniaxial compression experiments of single crystals at the micrometer scale. Collectively, the studies discovered new regimes of plastic flow that are size-scale dependent and that occur in the absence of strong strain gradients. However, the quantitative comparison of the flow curves between independent studies is hampered by differences in the particular implementations of the testing methodology. Modeling of microcompression experiments using 3-D discrete dislocation simulations has provided valuable insight into the mechanisms that control plastic flow in FCC metals. These efforts identified the importance of the initial dislocation density and distribution of mobile dislocation segments, the influence of free surfaces on that distribution, as well as altered multiplication and hardening responses due to the finite source statistics. Microcrystal experiments also provide a new pathway to characterize the global system dynamics of dislocation ensembles and associated stochastic processes.
Paradoxes of China's Economic Boom
Authors: Whyte Martin King
Published: July 2009

China's stunning economic performance for the past three decades was not only unexpected but contradicts much received wisdom in the study of development. Four paradoxes posed by China's record are critically examined: (a) China's traditional culture and institutions as obstacles to development; (b) the necessity of big bang comprehensive reforms to transform a centrally planned economy into a market economy; (c) the perils of state-directed economic development (especially when the state is composed of lifelong communist bureaucrats); and (d) the necessity of getting the institutions right in order to foster development, particularly by establishing secure private property rights. Reasons why China was able to defy expectations and the received wisdom and develop so successfully are discussed. The Chinese case indicates that countries cannot succeed at development by a standard cookbook approach but must tailor their development policies and institutions to their distinctive history, potentials, and limitations.
Ethnicity, Race, and Nationalism
Authors: Brubaker Rogers
Published: July 2009

This article traces the contours of a comparative, global, cross-disciplinary, and multiparadigmatic field that construes ethnicity, race, and nationhood as a single integrated family of forms of cultural understanding, social organization, and political contestation. It then reviews a set of diverse yet related efforts to study the way ethnicity, race, and nation work in social, cultural, and political life without treating ethnic groups, races, or nations as substantial entities, or even taking such groups as units of analysis at all.
Social Class Differentials in Health and Mortality: Patterns and Explanations in Comparative Perspective
Authors: Elo Irma T.
Published: July 2009

Social class inequalities in health and mortality have become an increasingly prominent topic of study among sociologists, demographers, economists, and social epidemiologists. Considerable progress has been made in documenting such inequalities in a wide variety of settings using multiple measures of health and all-cause and cause-specific mortality. That social class inequalities are pervasive is now well established, but factors that underlie them are less clearly understood. This review discusses various measures used to define social class in studies of health inequalities. It then reviews the literature on patterns of these inequalities in developed countries as well as their potential explanations. Promising new research approaches include those that employ a life course perspective in the study of health inequalities and those that integrate multiple levels of analysis, including biological pathways that are likely to be involved in translating cumulative adversity to poor health.
Solid-Surface Characterization by Wetting
Authors: Marmur Abraham
Published: July 2009

The current status of the theories that are required for characterization of solid surfaces by equilibrium contact angles is reviewed. Some important aspects, which are not yet completely understood, are explained and listed as future challenges. The theoretical conclusions are integrated into a methodology and technique for contact angle measurement and interpretation that avoid existing pitfalls.
Intergenerational Family Relations in Adulthood: Patterns, Variations, and Implications in the Contemporary United States
Authors: Swartz Teresa Toguchi
Published: July 2009

Recent research suggests that intergenerational relations—the relationships between adult children and their parents in particular—are becoming increasingly important to Americans. Two main social forces appear to be driving these changes: marital instability and broader demographic shifts. Intergenerational relationships involve both affective ties and more instrumental forms of support such as financial resources or child care. Although actual material assistance tends to be episodic and primarily responsive to specific needs, these relationships appear to be durable and flexible and often fill in when marriage or other emotional attachments deteriorate. As such, intergenerational family relations may reflect adaptations to contemporary, postmodern economic and cultural conditions. Variations in these general patterns and dynamics are also exhibited, the most striking of which are those involving race and class. These variations are driven largely by social structure and position and suggest that intergenerational relations constitute an important and largely hidden aspect of how families contribute to the reproduction of social inequality in society. These findings reinforce the value of extending both scholarly and cultural notions of family beyond the traditional nuclear family model.
Effects of FR‐91 on Immune Cells from Healthy Individuals and from Patients with Non‐Hodgkin Lymphoma
Authors: Lombardi V. R. M. , Martínez E. , Chacón R. , Etcheverría I. , Cacabelos R.
Published: July 2009

The immune system is subject to destruction and dysfunction as a result of attacks by pathogenic and environmental agents. In addition, many clinical situations exist in which it is desirable to stimulate or suppress the immune system. The present study evaluated the screening efficacy of flow cytometric lymphocyte subset typing in peripheral blood mononuclear cells from healthy individuals (HI) and from patients with non‐Hodgkin lymphoma (NHL) treated with different concentrations of FR‐91, a standardized lysate of microbial cells belonging to the Bacillus genus, and in vitro cytokine production. Increased expression of subset markers (CD3, CD4, CD8) in NHL and CD3 in HI suggests an immunomodulating effect of FR‐91. In addition the results of cytokine production also demonstrated a clear effect of FR‐91 on both populations. A significant increase of IL‐6, IL‐12, IFN‐γ
and TNF‐α was observed in the HI group after treatment with FR‐91. In a similar manner an increase of IL‐2, IL‐6, IL‐12, IFN‐γ
and TNF‐α was also observed in the NHL group. In conclusion FR‐91 seems to affect lymphocyte subpopulations, in vitro cytokine production, as well as mitogen‐induced lymphocyte activation in a dose‐dependent manner in both healthy individuals and NHL patients.
A Phytogeographical Classification of the North American Pacific Coast Based on Climate, Vegetation and a Floristic Analysis of Vascular Plants
Authors: Peinado Manuel , Macías Miguel Ángel , Aguirre Juan Luis , Delgadillo José
Published: July 2009

This study was designed to explore floristic variation along the Pacific coast from Cook Inlet, Alaska, to the southern tip of Baja California, Mexico. Data corresponding to 965
phytosociological relevés (including 686 vascular plants) obtained by sampling 279 coastal sites
were examined. Using an objective classification system (Average Linkage Clustering), floristic
data acquired in fieldwork were related to the macroclimates of the study area. The registered taxa
were grouped into phytogeographical elements, giving rise to a phytogeographical classification in
which eight floristic provinces were distinguished. Floristic differences among provinces were
correlated with palaeoclimatic and palaeogeographical events. The boreal and temperate provinces
show high percentages of broadly distributed elements, whose origins can be found in the
Boreotropical or Arcto-Tertiary geoflora that dominated the Northern Hemisphere during the
Tertiary. The floristically richest provinces are the three that occupy the Mediterranean zone, since
these provinces harbour elements of Arcto-Tertiary and Madro-Tertiary geofloras. The flora of
tropical Baja California is characterised by a high number of taxa related to Neotropical flora,
especially to those showing links with South America.
Generalized Hyers‐Ulam Stability of Generalized (N, K)‐Derivations
Authors: Eshaghi Gordji M. , Rassias J. M. , Ghobadipour N.
Published: July 2009

Let 3 ≤ n, and 3 ≤ k ≤ n be positive integers. Let A be an algebra and let X be an A‐bimodule. A ℂ‐linear
mapping d : A → X is called a generalized (n, k)‐derivation if
there exists a (k − 1)‐derivation δ : A → X such that
d(a1a2 ⋯ an) = δ(a1)a2 ⋯ an + a1δ(a2)a3 ⋯ an + ⋯+a1a2 ⋯ ak−2δ(ak−1)ak ⋯ an + a1a2 ⋯ ak−1d(ak)ak+1 ⋯ an + a1a2 ⋯ akd(ak+1)ak+2 ⋯ an + a1a2 ⋯ ak+1d(ak+2)ak+3 ⋯ an + ⋯+a1 ⋯ an−1d(an) for all a1, a2, …, an ∈ A. The main purpose of this paper is
to prove the generalized Hyers‐Ulam stability of the generalized
(n, k)‐derivations.
MicroRNA‐Biogenesis and Pre‐mRNA Splicing Crosstalk
Authors: Shomron Noam , Levy Carmit
Published: July 2009

MicroRNAs (miRNAs) are often hosted in introns of protein‐coding genes. Given that the same transcriptional unit can potentially give rise to both miRNA and mRNA transcripts raises the intriguing question of the level of interaction between these processes. Recent studies from transcription, pre‐mRNA splicing, and miRNA‐processing perspectives have investigated these relationships and yielded interesting, yet somewhat controversial findings. Here we discuss major studies in the field.
Dephosphorylation of Centrins by Protein Phosphatase 2C and
Authors: Thissen Marie-Christin , Krieglstein Josef , Wolfrum Uwe , Klumpp Susanne
Published: July 2009

In the present study, we identified protein phosphatases dephosphorylating centrins previously phosphorylated by protein kinase CK2. The following phosphatases known to be present in the retina were tested: PP1, PP2A, PP2B, PP2C, PP5, and alkaline phosphatase. PP2C and were capable of dephosphorylating P--centrin1 most efficiently. PP2C was inactive and the other retinal phosphatases also had much less or no effect. Similar results were observed for centrins 2 and 4. Centrin3 was not a substrate for CK2. The results suggest PP2C and to play a significant role in regulating the phosphorylation status of centrins in vivo.