bluuebunny/crossref_metadata_2025 huggingface dataset:
Legal Basis of Consent for Health Care and Vaccination for Adolescents
Authors: English Abigail , Shaw Frederic E. , McCauley Mary M. , Fishbein Daniel B. ,   for the Working Group on Legislation, Vaccination, and Adolescent Health
Published: January 2008

State law is generally the controlling authority for whether parental consent is required or minors may consent for their own health care, including vaccination. At the federal level, no vaccination consent law exists; however, federal law requires that vaccine information statements be given to the parent or another person who is qualified under state law to consent to vaccination of a minor. All states allow minors to consent for their own health care in some circumstances on the basis of either (1) their status (eg, age, emancipation, marriage) or (2) the kind of health care services they are seeking (eg, family planning services, treatment of sexually transmitted disease). In each state, a specific analysis of laws will be required to determine the circumstances under which a minor can consent for vaccination.
Stilbene derivatives that are colchicine site microtubule inhibitors have antileukemic activity and minimal systemic toxicity
Authors: Cao Thai M. , Durrant David , Tripathi Ashutosh , Liu Jihua , Tsai Schickwann , Kellogg Glen E. , Simoni Daniele , Lee Ray M.
Published: January 2008

Stilbenes are a group of natural compounds with many biological activities. Two highly potent stilbenes, cis‐3,4′,5‐trimethoxy‐3′‐aminostilbene (stilbene 5c) and cis‐3,4′,5‐trimethoxy‐3′‐hydroxystilbene (stilbene 6c) induce G2/M cell‐cycle arrest and leukemic cell death in nanomolarity range without affecting normal bone marrow progenitor cells. The mechanism of stilbenes is mediated by interfering with microtubule polymerization through the colchicine‐binding site. Docking of the stilbenes into tubulin structure confirms that stilbenes fit into the colchicine‐binding pocket. Animal studies show that stilbenes are well tolerated in mice and are capable of inducing more than 50% leukemic cell death by a single dose injection. A 5‐day treatment with low‐dose stilbenes suppresses tumor growth in mice with established tumor xenografts. No major organ damage was detected by histological section. Our results indicate that stilbene 5c is a microtubule‐interfering agent and can be potentially useful in leukemic therapy. Am. J. Hematol., 2008. © 2008 Wiley‐Liss, Inc.
Identification of Putative Binding Sites of P‐glycoprotein Based on its Homology Model
Authors: Globisch Christoph , Pajeva Ilza K. , Wiese Michael
Published: January 2008

A homology model of P‐glycoprotein based on the crystal structure of the multidrug transporter Sav1866 is developed, incorporated into a membrane environment, and optimized. The resulting model is analyzed in relation to the functional state and potential binding sites. The comparison of modeled distances to distances reported in experimental studies between particular residues suggests that the model corresponds most closely to the first ATP hydrolysis step of the protein transport cycle. Comparison to the protein 3D structure confirms this suggestion. Using SiteID and Site Finder programs three membrane related binding regions are identified: a region at the interface between the membrane and cytosol and two regions located in the transmembrane domains. The regions contain binding pockets of different size, orientation, and amino acids. A binding pocket located inside the membrane cavity is also identified. The pockets are analyzed in relation to amino acids shown experimentally to influence the protein function. The results suggest that the protein has multiple binding sites and may bind and/or release substrates in multiple pathways.
Crystal growth, crystal structure and physical properties of polar orthorhombic tris(glycine) zinc chloride
Authors: Fleck M. , Becker P. , Bayarjargal L. , Ochrombel R. , Bohatý L.
Published: January 2008

Large single crystals of the polar (point group mm 2) compound tris(glycine) zinc chloride, (NH3CH2COO)3 · ZnCl2, were grown from aqueous solutions. The refractive indices were measured in the wavelength region from 365 nm to 1083 nm and an unpolarised absorption spectrum was recorded (transparency range from 260 to 1550nm). The phase matching conditions for second harmonic generation were analysed: both, type I (ss‐f) and type II (sf‐f) are possible in the red and near IR region. All five components of the piezoelectric tensor [dijk ] were determined; the maximum values of longitudinal and transverse piezoelectric effects are less than one half of d111 of α‐quartz. In addition, a redetermination of the crystal structure (including location of H atoms) is presented. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Clinical approaches to axis II comorbidity: commentary
Authors: Clarkin John F.
Published: January 2008

In a review of six clinical cases involving the treatment of a patient with two or more personality disorders according to theDiagnostic and Statistical Manual of Mental Disorders, Fourth Edition‐Text Revision(DSM‐IV; American Psychiatric Association,1994), five key decisions that have an impact on treatment emerged. The clinical cases are discussed and compared from the vantage points of the nature of personality disorder, extent and content of patient assessment, treatment focus and sequence, and the role of the patient–therapist relationship. The cases illuminate the complexity of these patients and the need for careful treatment construction. © 2008 Wiley Periodicals, Inc. J Clin Psychol: In Session 64: 1–9, 2008.
Environmentally friendly LC for the simultaneous determination of ascorbic acid and its derivatives in skin‐whitening cosmetics
Authors: Balaguer Angel , Chisvert Alberto , Salvador Amparo
Published: January 2008

Ascorbic acid (AA), also known as vitamin C, is a very popular skin‐whitening agent used in cosmetics. However, the use of AA (and also its sodium or magnesium salts) in cosmetic products is limited owing to its labile oxidative properties. In order to avoid its early degradation, different derivatives have been designed, such as ascorbyl phosphate (APH; as magnesium or sodium salts) and ascorbyl palmitate (AP), and more recently the ascorbyl glucoside (AG). Bearing in mind that all these chemicals in skin‐whitening cosmetic products must be determined in order to control the efficacy of such products, this paper focuses on developing a wide‐ranging LC analytical method able to determine the above‐mentioned compounds simultaneously in cosmetic products. The chromatographic variables were studied and selected in order to achieve the total separation and subsequent determination of all the analytes involved. Thus, an octadecylsilica (C18) stationary phase and a mobile phase gradient of ethanol: 50 mM phosphate buffer at different pHs (containing 0.1 M NaCl) were used. Detection was carried out with a UV/visible spectrometry detector set at different wavelengths. The LOD ranged from 2 to 6 μg/mL depending on the analyte. The proposed method was validated by analysing a laboratory‐made and six commercial skin‐whitening cosmetic samples. The method allows any mixture of the four skin‐whitening agents studied to be both separated at good resolution and determined without interferences from samples, and moreover it does not require the use of either highly toxic organic solvents or hazardous chemicals.
Low‐ and zero‐sulphated ash, phosphorus and sulphur anti‐wear additives for engine oils
Authors: Spikes Hugh
Published: January 2008

Modern engine lubricant specifications include compositional constraints in terms of the permitted level of sulphated ash, phosphorus and sulphur (SAPS). This necessitates a reduction in the concentration of the additive zinc dialkyldithiophosphate (ZDDP) used in engine oils, and there is currently great interest in identifying anti‐wear additives that contain low or zero SAPS to partially or wholly replace ZDDP.

This paper reviews the main chemical classes that are reported in the literature as potential low‐ or zero‐SAPS anti‐wear agents. There are many such possible additives, although none appears to be quite as versatile as ZDDP. Instead, combinations of anti‐wear and extreme pressure additives are likely to be employed in the future. The literature reveals a strong imbalance in the amount and depth of research carried out on the various additive types, with a great deal of research on a few classes of additives and very little recent work on most others. Copyright © 2007 John Wiley & Sons, Ltd.
Lesion of the centromedian thalamic nucleus in MPTP‐treated monkeys
Authors: Lanciego Jose L. , Rodríguez‐Oroz Maria C. , Blesa Francisco J. , Alvarez‐Erviti Lydia , Guridi Jorge , Barroso‐Chinea Pedro , Smith Yoland , Obeso Jose A.
Published: January 2008

The caudal intralaminar nuclei are a major source of glutamatergic afferents to the basal ganglia. Experiments in the 6‐hydroxydopamine rat model have shown that the parafascicular nucleus is overactive and its lesion alleviates basal ganglia neurochemical abnormalities associated with dopamine depletion. Accordingly, removal of this excitatory innervation of the basal ganglia could have a beneficial value in the parkinsonian state. To test this hypothesis, unilateral kainate‐induced chemical ablation of the centromedian thalamic nucleus (CM) has been performed in MPTP‐treated monkeys. Successful lesions restricted to the CM boundaries (n = 2) without spreading over other neighboring thalamic nuclei showed an initial, short‐lasting, and mild change in the parkinsonian motor scale but no effect against levodopa‐induced dyskinesias. The lack of significant and persistent motor improvement leads us to conclude that unilateral selective lesion of the CM alone cannot be considered as a suitable surgical approach for the treatment of PD or levodopa‐induced dyskinesias. The role of the caudal intralaminar nuclei in the pathophysiology of movement disorders of basal ganglia origin remains to be clarified. © 2007 Movement Disorder Society
Identification of a de novo Lys304Gln mutation in the glycine receptor α‐1 subunit gene in a Korean infant with hyperekplexia
Authors: Kang Hoon‐Chul , Jeong You Su , Jae Chey Myung , Sam Baik Jong , Kim Jong‐Won , Ki Chang‐Seok
Published: January 2008

Startle disease or hyperekplexia (STHE; MIM 149400) is a rare disorder that is characterized by marked muscular hypertonia in infancy and an exaggerated startle response to unexpected acoustic or tactile stimuli. Mutations in the gene encoding the α‐1 subunit of the inhibitory glycine receptor (GLRA1) were reported as causes of STHE. Recently, we encountered a Korean male infant with generalized stiffness that was observed from the first 3 days of life. The abnormal startle response was evident from the fourth week of life, and he showed marked improvement in the startle response and muscle hypertonia after being administered phenobarbital and clonazepam. Direct sequencing analysis of the infant and his parents revealed a de novo variation (c.910A>C) in the GLRA1 gene, resulting in a novel Lys304Gln missense mutation. © 2007 Movement Disorder Society
Nail fold capillary observation in replanted severed fingers
Authors: Lu Wei , Wang Daping , Liu Lijun , Xiong Jianyi , He Qianwen
Published: January 2008

Observation of circulation in replanted severed fingers often relies on the clinical experience of the doctor. This article discusses nail fold capillary loops (NFCL) observation in the monitoring of the perfusion and circumfluence of replanted digits. In our study, 30 patients with a total of 39 replanted digits were selected. The WX‐9A900 Microcirculation Checkout System (MCS) was adopted to perform evaluation of circulation postoperatively. The digits were monitored by clinical examination and MCS at 5‐ to 7‐h intervals for 24 h and then at 2‐days intervals for 14 days. Our results showed that seven digits were observed with inadequate venous circumfluence, and large, long NFCL presented within 6–12 h postoperatively. Among the replanted digits, two replants resulted in venous crisis that did respond to an arterial interdiction test, and needed venous grafts. Two digits were observed to have insufficient arterial supply, one of which resulted in arterial crisis. In this case, NFCL could not be observed and had no response to vein interdiction test. This case needed venous graft to rebuild blood perfusion, and survived eventually. We concluded therefore, that compared with the former studies, NFCL correlates closely with the perfusion and circumfluence of the replanted digits. MCS is noninvasive, reliable, and a direct method in postoperative monitoring of digit replanted. © 2008 Wiley‐Liss, Inc. Microsurgery, 2008.
Candidate genes involved in enhanced growth of human prostate cancer under high fat feeding identified by microarray analysis
Authors: Narita Shintaro , Tsuchiya Norihiko , Saito Mitsuru , Inoue Takamitsu , Kumazawa Teruaki , Yuasa Takeshi , Nakamura Akira , Habuchi Tomonori
Published: January 2008

BACKGROUND

Several studies have suggested that a high fat diet (HFD) may be a risk factor of prostate cancer (PCa). As a first step to delineate the molecular mechanisms underlying the enhanced progression of PCa under HFD, we investigated the differential gene expressions of a human PCa xenograft under HFD and a low fat diet (LFD).

METHODS

LNCaP cells were subcutaneously injected in 20 nude mice, which were equally divided into two groups, the HFD group and LFD group. Oligonucleotide microarray analyses were performed using mice xenografts from HFD and LFD, and the results of candidate genes with a significant differential expression were validated by quantitative RT‐PCR experiments. As for insulin‐like growth factor I receptor (IGF‐IR), protein expression levels were further examined by immunohistochemistry in xenograft tissues and in 78 radical prostatectomy specimens.

RESULTS

Tumor volume and serum PSA levels were significantly higher in the HFD group than in the LFD group (P < 0.001 and P = 0.006, respectively). We found 64 up‐regulated genes (0.19%) and 14 down‐regulated genes (0.04%) with more than twofold differences in the HFD xenograft. IGF‐IR, TNFRSF, and LPL showed striking differences in the quantitative RT‐PCR experiment. Immunostaining further revealed marked enhanced IGF‐IR expression in the HFD xenograft. In human PCa, the lowest IGF‐IR immunoreactivity group tended to have the lowest body mass index in both normal and PCa epithelium.

CONCLUSION

HFD induced remarkable up‐ and down‐regulation of mRNA of a substantial number of genes. Furthermore, the IGF‐I system may be involved in the HFD‐associated enhanced progression of PCa. Prostate 68: 321–335, 2008. © 2008 Wiley‐Liss, Inc.
Functional and computational studies of the ligand‐associated metal binding site of β3 integrins
Authors: Murcia Marta , Jirouskova Marketa , Li Jihong , Coller Barry S. , Filizola Marta
Published: January 2008

A combination of experimental and computational approaches was used to provide a structural context for the role of the β3 integrin subunit ligand‐associated metal binding site (LIMBS) in the binding of physiological ligands to β3 integrins. Specifically, we have carried out (1) adhesion assays on cells expressing normal αIIβ3, normal αVβ3, or the corresponding β3 D217A LIMBS mutants; and (2) equilibrium and nonequilibrium (steered) molecular dynamics (MD) simulations of eptifibatide in complex with either a fully hydrated normal αIIβ3 integrin fragment (αIIb β‐propeller and the β3 βA (I‐like), hybrid, and PSI domains) or the equivalent β3 D217A mutant. Normal αIIβ3 expressing cells adhered to immobilized fibrinogen and echistatin, whereas cells expressing the αIIβ3 D217A LIMBS mutant failed to adhere to either ligand. Similarly, the equivalent αVβ3 mutant was unable to support adhesion to vitronectin or fibrinogen. The αIIβ3 D217A mutation increased the binding of mAb AP5, which recognizes a ligand‐induced binding site (LIBS) in the β3 PSI domain, indicating that this mutation induced allosteric changes in the protein. Steered MD simulating the unbinding of eptifibatide from either normal αIIβ3 or the equivalent β3 D217A mutant suggested that the reduction in ligand binding caused by the LIMBS mutant required the loss of both the LIMBS and the metal ion‐dependent adhesion site (MIDAS) metal ions. Our computational results indicate that the LIMBS plays a crucial role in ligand binding to αIIβ3 by virtue of its effects on the coordination of the MIDAS. Proteins 2008. © 2008 Wiley‐Liss, Inc.
Risk Prediction for Development of Pancreatic Fistula Using the ISGPF Classification Scheme
Authors: Pratt Wande B. , Callery Mark P. , Vollmer Charles M.
Published: January 2008

Background:

The International Study Group on Pancreatic Fistula (ISGPF) classification scheme has become a useful system for characterizing the clinical impact of pancreatic fistula. We sought to identify predictive factors that predispose patients to fistula, specifically those with clinical relevance (grades B/C), and to describe the clinical and economic significance of risk stratification within this framework.

Methods:

Overall, 233 consecutive pancreatoduodenectomies were performed between October 2001 and March 2007 in our institution. Pancreatic fistula is defined according to the ISGPF classification scheme. Logistic regression analysis was performed to identify risk factors for pancreatic fistula development. These features were then analyzed to determine whether additive risk severity equates to worsening clinical and economic impact.

Results:

Fistulas of any extent occurred in 60 patients, but only 31 (14%) were clinically relevant. There are no identifiable risk factors for grade A biochemical fistulas. Multivariate analysis shows that small pancreatic duct size (<3 mm); soft gland texture; ampullary, duodenal, cystic, or islet cell pathology; and increased intraoperative blood loss (> 1,000 ml) are associated with clinically relevant fistulae. An additive effect is further illustrated, in which clinical and economic outcomes progressively worsen as risk profile increases. Each additional risk factor increases the odds of developing a clinically relevant fistula by 52%.

Conclusions:

For pancreatoduodenectomy, small duct size; soft gland texture; ampullary, duodenal, cystic, or islet cell pathology; and increased intraoperative blood loss are convincing risk factors for the development clinically relevant fistulae as judged by ISGPF classification. As risk profile accrues, patients suffer more complications, encounter longer hospital stays, and incur greater hospital costs. These outcomes can be predicted in the operating room through accurate delineation of high‐risk glands.
Modern Sequential Analysis and Its Applications to Computerized Adaptive Testing
Authors: Bartroff Jay , Finkelman Matthew , Lai Tze Leung
Published: January 2008

After a brief review of recent advances in sequential analysis involving sequential generalized likelihood ratio tests, we discuss their use in psychometric testing and extend the asymptotic optimality theory of these sequential tests to the case of sequentially generated experiments, of particular interest in computerized adaptive testing. We then show how these methods can be used to design adaptive mastery tests, which are asymptotically optimal and are also shown to provide substantial improvements over currently used sequential and fixed length tests.
Expressed sequence tags from cynomolgus monkey (Macaca fascicularis) liver: A systematic identification of drug‐metabolizing enzymes
Authors: Uno Yasuhiro , Suzuki Yutaka , Wakaguri Hiroyuki , Sakamoto Yoshiko , Sano Hitomi , Osada Naoki , Hashimoto Katsuyuki , Sugano Sumio , Inoue Ituro
Published: January 2008

The liver, a major organ for drug metabolism, is physiologically similar between monkeys and humans. However, the paucity of identified genes has hampered a deep understanding of drug metabolism in monkeys. To provide such a genetic resource, 28 655 expressed sequence tags (ESTs) were generated from a cynomolgus monkey liver full‐length enriched cDNA library, which contained 23 unique ESTs homologous to human drug‐metabolizing enzymes. Our comparative genomics approach identified nine lineage‐specific candidate ESTs, including three drug‐metabolizing enzymes, which could be important for understanding the physiological differences between monkeys and humans.
How wide is the riparian zone of small streams in tropical forests? A test with terrestrial herbs
Authors: Drucker Debora Pignatari , Costa Flávia Regina Capellotto , Magnusson William E.
Published: January 2008

Although it is well known that riparian zones can contribute strongly to between-habitat beta diversity, for most taxa it is not clear how far this ‘zone’ extends, and whether it corresponds to easily recognizable topographic features. Forty 200-m2 plots were installed in a terra firme tropical forest to detect compositional variation in terrestrial herbs from the margins of small streams to the uplands. Plots were ordinated by their dissimilarity in species composition with non-metric multidimensional scaling. The riparian zone around streams was distinct in understorey herb composition from upland areas for about 100 m from the streams, or about 70 m asl in elevation, the exact distance depending on the size of the stream valley. However, the only assemblage that was almost completely distinct occurred as a narrow band a few metres wide along the streams. The rest of the riparian zone appears to represent an ecotone with continuous change, most of which occurs out to a distance of about half the width of the riparian zone as we defined it. Although riparian zones are legally protected in Brazil, they are frequently degraded. The complex factors leading to zonation around streams need to be understood to effectively manage these areas.
Prosodically-conditioned variability in children's production of French determiners
Authors: DEMUTH KATHERINE , TREMBLAY ANNIE
Published: January 2008

Researchers have long noted that children's grammatical morphemes are variably produced, raising questions about when and how grammatical competence is acquired. This study examined the spontaneous production of determiners by two French-speaking children aged 1 ; 5–2 ; 5. It found that determiners were produced earlier with monosyllabic words, and later with disyllabic and trisyllabic words. This suggests that French-speaking children's early determiners are prosodically licensed as part of a binary foot, with determiners appearing more consistently only once prosodic representations become more complex. This study therefore provides support for the notion that grammatical morphemes first appear in prosodically licensed contexts, suggesting that some of the early variability in morphological production is systematic and predictable.
A comparison between the hourly autoscaled and manually scaled characteristics from the Chilton ionosonde from 1996 to 2004
Authors: Bamford R. A. , Stamper R. , Cander L. R.
Published: January 2008

Most monitoring ionosonde stations now rely on automatic processing rather than manual processing to provide ionospheric characteristics. A systematic assessment was made of the quality of all the key ionospheric characteristics scaled automatically from hourly ionograms from the midlatitude Chilton ionosonde in the United Kingdom, by comparing them with the definitive values produced by manual scaling. The data for the study were a nearly continuous series of hourly values covering the majority of solar cycle 23 from 1996 to the end of 2004. This period includes solar maximum and minimum conditions and quiet and disturbed intervals, and the investigation is the first comprehensive examination of the performance of automatic scaling without any data preselection over such an extended period. The accuracy of autoscaled values during storm periods was examined against the global storm index Dst for the whole 9‐year data set. Geomagnetic conditions were found to have only a small effect on autoscaling performance, with the most important identifiable cause of error being the truncation of automatic layer traces due to broadcast interference. Overall, the performance of the autoscaling algorithms was found to be acceptable, with the characteristics foF2, h′E, M(3000)F2, and MUF(3000)F2 within defined error bounds for more than 90% of the time and all characteristics within these bounds more than 80% of the time.
Do stable atmospheric layers exist?
Authors: Lovejoy S. , Tuck A. F. , Hovde S. J. , Schertzer D.
Published: January 2008

The notion of stable atmospheric layers is a classical idealization used for understanding atmospheric dynamics and thermodynamics. Using state of the art drop sonde data and using conditional, dynamical and convective stability criteria we show that apparently stable layers are typically composed of a hierarchy of unstable layers themselves with embedded stable sublayers, and unstable sub‐sub layers etc. i.e. in a Russian Matryoshka doll‐like fractal hierarchy. We therefore argue that the notion of stable atmospheric layers is untenable and must be replaced by modern scaling notions.
A dynamic density functional theory for particles in a flowing solvent
Authors: Rauscher Markus , Domínguez Alvaro , Krüger Matthias , Penna Florencia
Published: January 2008

We present a dynamic density functional theory (dDFT) which takes into account the advection of the particles by a flowing solvent. For potential flows, we can use the same closure as in the absence of solvent flow. The structure of the resulting advected dDFT suggests that it could be used for nonpotential flows as well. We apply this dDFT to Brownian particles (e.g., polymer coils) in a solvent flowing around a spherical obstacle (e.g., a colloid) and compare the results with direct simulations of the underlying Brownian dynamics. Although numerical limitations do not allow for an accurate quantitative check of the advected dDFT both show the same qualitative features. In contrast to previous works which neglected the deformation of the flow by the obstacle, we find that the bow wave in the density distribution of particles in front of the obstacle as well as the wake behind it are reduced dramatically. As a consequence, the friction force exerted by the (polymer) particles on the colloid can be reduced drastically.
Computation of interfacial properties via grand canonical transition matrix Monte Carlo simulation
Authors: Grzelak Eric M. , Errington Jeffrey R.
Published: January 2008

We examine two free-energy-based methods for studying the wetting properties of a fluid in contact with a solid substrate. Application of the first approach involves examination of the adsorption behavior of a fluid at a single substrate, while the second technique requires investigation of the properties of a system confined between two parallel substrates. Both of the techniques rely upon computation and analysis of the density dependence of a system’s surface free energy and provide the contact angle and solid-vapor and solid-liquid interfacial tensions for substrate-fluid combinations within the partial wetting regime. Grand canonical transition matrix Monte Carlo simulation is used to obtain the required free-energy curves. The methods examined within this work are general and are applicable to a wide range of molecular systems. We probe the performance of the methods by computing the interfacial properties for two systems in which an atomistic fluid interacts with a fcc crystal. For both of the systems studied we find good agreement between our results and those obtained via the mechanical definition of the interfacial tension.
Stress-induced band gap tuning in ⟨112⟩ silicon nanowires
Authors: Lu A. J. , Zhang R. Q. , Lee S. T.
Published: January 2008

We show via density functional calculations that the electronic band structures of ⟨112⟩-oriented hydrogenated silicon nanowires (SiNWs) could be significantly altered by axial stresses. In particular, an axial compression could cause an indirect-to-direct band gap transition in ⟨112⟩ SiNWs. As direct energy band may induce strong light-emission properties of Si, the possibility of indirect-to-direct band transition via axial stress has fundamental implications in exploiting SiNWs for optoelectronic applications.
The size effect of nanoindentation on ZnO nanofilms
Authors: Cao Guoxin , Chen Xi
Published: January 2008

Nanoindentation behaviors of zinc oxide (ZnO) nanofilms with different film thicknesses are studied by using both molecular mechanics (MM) simulations and continuum analyses. It is found that there is a significant size effect on the indentation modulus obtained from MM simulations, which is absent in the continuum studies. The indentation modulus increases with the film thickness, and it also increases with the indentation depth; the trend of such a variation also depends on the film thickness. The contributions of the contact size effect, film thickness size effect, and microstructural size effect (surface effect) are elucidated and their couplings are explored. In addition, the substrate effect and nonlinear hyperelastic effect are incorporated to explain the size dependence of elastic indentation behaviors of ZnO nanofilms.
Measurement of temperature of laser cooled atoms by one-dimensional expansion in a magneto-optical trap
Authors: Pradhan S. , Jagatap B. N.
Published: January 2008

We discuss a simple time of flight technique for measurement of temperature of a cold cloud in a magneto-optical trap (MOT). The technique is based on spatiotemporal fluorescence imaging of the cloud that is allowed to undergo one-dimensional expansion in the presence of the orthogonal two-dimensional configuration of laser beams by temporal modulation of a pair of counterpropagating trapping beams in the MOT. We show that, in the time scale 0⩽t<5ms, the expansion of the cloud is ballistic and the temperature can be extracted from the time variation of the rms size of the cloud in the expansion direction. The reliability of the technique has been established by comparing the results with release and recapture method, and also by fitting them to the known temperature scaling law.
An analytical study of two-dimensional buckling of thin films on compliant substrates
Authors: Song J. , Jiang H. , Choi W. M. , Khang D. Y. , Huang Y. , Rogers J. A.
Published: January 2008

A stiff thin film on a heated compliant substrate may buckle when the system is cooled due to the thermal expansion mismatch between the film and substrate. Highly ordered and disordered herringbone patterns (wavy structures) then emerge as the system continues to cool. We have established an analytic approach to study one-dimensional, checkerboard, and ordered herringbone buckling patterns. The analytical approach gives the buckle wave length and amplitude in terms of the thin film and substrate elastic properties, thin film thickness, and the thermal strain. It is shown that the herringbone mode has the lowest energy, which explains why this mode is frequently observed in experiments. These classes of materials might be interesting as a route to high performance electronics with full, two-dimensional stretchability.
The effect of dopants on the dielectric constant of HfO2 and ZrO2 from first principles
Authors: Fischer Dominik , Kersch Alfred
Published: January 2008

Based on first-principles calculations, we elucidate the influence of dopants on the dielectric properties of the high-k materials HfO2 and ZrO2. Our calculations demonstrate that by doping the tetragonal phase can become energetically more favorable than the monoclinic phase present at ambient conditions. The stabilization of the tetragonal phase increases the dielectric constant significantly. A series of dopants was investigated to understand the efficiency and the mechanism of the stabilization process. The calculations reveal that at a moderate doping level (∼12%) only some of the dopants stabilize the tetragonal phase and that Si is the most efficient stabilizer atom.
Ferroelectric and piezoelectric properties of 0.948(K0.5Na0.5)NbO3–0.052LiSbO3 lead-free piezoelectric thick film by aerosol deposition
Authors: Ryu Jungho , Choi Jong-Jin , Hahn Byung-Dong , Park Dong-Soo , Yoon Woon-Ha
Published: January 2008

Lead-free, piezoelectric thick films of 0.948(K0.5Na0.5)NbO3–0.052LiSbO3 were fabricated by aerosol deposition and the effect of postannealing temperature on the dielectric, ferroelectric, and piezoelectric properties was investigated. The thickness of the films ranged from 5to17μm and highly dense films were obtained after deposition at room temperature. With increasing annealing temperature, the dielectric and ferroelectric properties were markedly increased. The maximum ferroelectric and dielectric properties of ε3T∕ε0=1012, Pr=15.5μC∕cm2, and d33=50pm∕V were obtained after annealing at 800°C for 1h. Above this temperature, the film exhibited rapid property degradation as it was decomposed due to Na2O evaporation.
Mounting fossil vertebrates
Authors: CROUCHER RON
Published: January 2008

The mounting of a fossil skeleton is a special and generally rare event for the museum preparator. The fossil must first be found then excavated, transported and carefully prepared, before consideration can be given to mounting it. Whilst the basic techniques of mounting are well known to specialists, the author emphasises innovations in the methods he has used during his 30 years as a preparator.
The Scandinavian Caledonides: a complexity of collisions
Authors: STEPHENS MICHAEL B.
Published: January 2008

Thrust sheets dominate the structural framework of the Scandinavian Caledonides. Sheets at lower tectonostratigraphic levels comprise the shortened margin of the continent Baltica and, at higher levels, terranes derived outboard from this continent in oceanic or foreign continental environments. Amalgamation of these terranes with the margin of Baltica occurred during closure of the Iapetus Ocean in the early Palaeozoic. Closure involved subduction of oceanic crust, extensional tectonics and continent‐arc collisions during the late Cambrian and early Ordovician, and ultimate continent‐continent collision during the Silurian and Devonian.
Mud diapirism: the origin of melanges in accretionary complexes?
Authors: BARBER TONY , BROWN KEVIN
Published: January 2008

Chaotic melange deposits, a mixture of blocks in a clay matrix, have commonly been attributed to the mechanism of submarine slumping. In the oceans at the present day slumping does not occur on a sufficiently large scale to produce the quantities of melange seen in ancient accretionary complexes. In modern accretionary complexes, massive shale diapirism produces large volumes of melange, and is an entirely adequate mechanism to account for melanges in ancient complexes.
A new look at the Lower Greensand using ground–penetrating radar
Authors: BRISTOW CHARLIE
Published: January 2008

The Wobum Sands Formation is Aptian to Albian in age and forms part of the lower Greensand Group, which crops out in the Weald Basin, East Anglia and the Isle of Wight. The sands are thought to have accumulated in a narrow tidal seaway connecting the Boreal Sea to the Tethys Ocean and early North Atlantic Ocean. Here I present new information on the geometry and internal character of large sedimentary structures exposed in sand pits near Leighton Buzzard, which have been imaged using ground–penetrating radar.
Carboniferous fossil forests
Authors: SCOTT ANDREW C. , CALDER JOHN H.
Published: January 2008

Forests of Carboniferous age, first described in detail in the nineteenth century, are often illustrated in textbooks, but their ecological and evolutionary significance has been largely overlooked or, worse, misrepresented. It has often been thought that the standing fossil forests found rooted in coals represent relicts of the peat‐forming vegetation. Recent research has suggested that this is not always the case and that many of the standing trees represent an essentially non‐peat‐forming wetland (‘clastic swamp’) vegetation comprising a distinctive set of genera and species of plants. Recent investigation of several famous examples ‐ Weaklaw, Arran and Joggins as well as new examples such as Mary Lee and Table Head ‐ is throwing new light on the ecological and evolutionary significance of these fossil forests.
EPR STUDIES ON CHLAMYDOMONAS REINHARDI
Authors: Weaver Ellen C. , Weaver Harry E.
Published: January 2008

Abstract— Observations of the two light induced EPR resonances in intact cells of Chlamy domonas reinhardi are presented. An action spectrum for the amplitude of the narrow, rapidly‐decaying R signal made with dilute suspensions has a peak at 680 mµ, lending support to the theory that this signal is due to chlorophylla. The decay mechanism for these spins apparently involves the oxygen‐producing system, since factors attenuating this activity enhance the R signal, and in some cases decrease or abolish the broad, slowly‐decaying S signal. It is pro posed that this latter resonance can be attributed to the seniiquinone of plastoquinone which may be maintained in n paramagnetic state by means of light energy absorbed by priiiiary or accessory pigments.
THE PHOTOCHEMICAL INTERACTION OF DEOXYRIBONUCLEIC ACID AND PROTEIN IN VIVO AND ITS BIOLOGICAL IMPORTANCE*,†
Authors: Smith Kendric C.
Published: January 2008

Summary When bacteria are irradiated with u.v. light there is a dose dependent decrease in the amount of DNA that can subsequently be extracted free of protein with detergent. This appears to be due to the crosslinking of the DNA with protein and the precipitation of the linked DNA when the denatured proteins are precipitated in the procedure used for the isolation of the DNA. The type of linkage between the DNA and the protein is unknown except that it resists the sequential attack of 2% sodium lauryl sulfate and 0.5 M KCI or 55% CsCI. The main evidence that the loss of DNA in vivo is due to the crosslinking of DNA and protein is that the crosslinking of DNA and protein can be demonstrated in vitro. X‐rays do not crosslink DNA and protein in vivo, but acridine orange and visible light cause the crosslinking of DNA and protein both in vivo and in vitro.

By pulse labeling the DNA of bacteria with tritated thymine it can be shown that newly synthesized DNA is most sensitive to crosslinking and that this sensitivity shows a cyclic response keyed to the generation time of the bacteria. Under conditions of thymine starvation where the intrinsic sensitivity of the cells to killing by u.v. is markedly increased, there is a parallel increase in the sensitivity of the DNA of these cells to be crosslinked to protein. The similarity in the time sequence of these two events strongly suggests that the crosslinking may play an important role in the loss of viability following u.v. irradiation.
ENERGY TRANSFER AND CYTOCHROME FUNCTION IN A NEW TYPE OF PHOTOSYNTHETIC BACTERIUM*
Authors: Olson John M. , Nadler Kenneth D.
Published: January 2008

Abstract— The excitation spectrum for bacteriochlorophyll b fluorescence at 1027 mp in Rhodopseudomas sp. NHTC 133 indicates that the efficiency of energy transfer from carotenoid to bacteriochlorophyll b is between 27 and 28 per cent.

Light‐induced absorbancy changes in anaerobic whole cells indicated the oxidation of three c‐type cytochromes (C‐550.5, C‐553, C‐558) and one b‐type cytochrome or cytochromoid C (C‐560). At low light intensities C‐553 is the main cytochrome oxidized, while at high light intensities mainly C‐558 is oxidized in addition to C‐553. The light responses of the heme proteins appear to be similar to those observed previously in purple and green photosyn‐thetic bacteria. No light‐induced shifts in carotenoid absorption bands were detected.

In bacterial extracts C‐553 and C‐558 are bound to the chromatophores, while C‐550.5 is soluble.
The
pervasive
discourse
Authors: Nieuwdorp Eva
Published: January 2008

In this article I argue for a critical analysis and re-evaluation of the term pervasive. Due to ambiguous definitions in both the discourse on computing and gaming, this term has become theoretically entangled with others. This has led to multiple definitions, and also, in the case of gaming, to the neglect of the different perspectives in which a game can be pervasive. In the current nascent stage of research into pervasive gaming, in which attempts are being made to theorize this concept, I argue for an analytical overview of the use of the term pervasive in order to understand the different perspectives in which it is used.
Improving the efficacy of automated sign language practice tools
Authors: Brashear Helene
Published: January 2008

CopyCat is an America Sign Language (ASL) game, which uses gesture recognition technology to help young Deaf children practice ASL skills. Our database of signing samples was collected from user studies of Deaf children playing a Wizard of Oz version of the game at the Atlanta Area School for the Deaf. We have created an automatic sign language recognition system for the game. We believe that we can improve the accuracy of this system by characterizing and modeling disfluencies found in the children's signing.
Control of Flow Over a Bluff Body
Authors: Choi Haecheon , Jeon Woo-Pyung , Kim Jinsung
Published: January 2008

In this review, we present control methods for flow over a bluff body such as a circular cylinder, a 2D bluff body with a blunt trailing edge, and a sphere. We introduce recent major achievements in bluff-body flow controls such as 3D forcing, active feedback control, control based on local and global instability, and control with a synthetic jet. We then classify the controls as boundary-layer controls and direct-wake modifications and discuss important features associated with these controls. Finally, we discuss some other issues such as Reynolds-number dependence, the lowest possible drag by control, and control efficiency.
Density Stratification, Turbulence, but How Much Mixing?
Authors: Ivey G.N. , Winters K.B. , Koseff J.R.
Published: January 2008

We examine observations of turbulence in the geophysical environment, primarily from oceans but also from lakes, in light of theory and experimental studies undertaken in the laboratory and with numerical simulation. Our focus is on turbulence in density-stratified environments and on the irreversible fluxes of tracers that actively contribute to the density field. Our understanding to date has come from focusing on physical problems characterized by high Reynolds number flows with no spatial or temporal variability, and we examine the applicability of these results to the natural or geophysical-scale problems. We conclude that our sampling and interpretation of the results remain a first-order issue, and despite decades of ship-based observations we do not begin to approach a reliable sampling of the overall turbulent structure of the ocean interior.
T Follicular Helper (TFH) Cells in Normal and Dysregulated Immune Responses
Authors: King Cecile , Tangye Stuart G. , Mackay Charles R.
Published: January 2008

T cell help for antibody production is a fundamental aspect of immune responses. Only recently has a better understanding of the cellular and molecular mechanisms for T cell help emerged. A subset of T cells, termed T follicular helper cells (TFHcells), provides a helper function to B cells and represents one of the most numerous and important subsets of effector T cells in lymphoid tissues. TFHcells are distinguishable from Th1 and Th2 cells by several criteria, including chemokine receptor expression (CXCR5), location/migration (B cell follicles), and function (B cell help). Central to the function of CD4+T cells is IL-21, a “helper” cytokine produced by TFHcells that potently stimulates the differentiation of B cells into Ab-forming cells through IL-21R. Consequently, dysregulation of TFHcell function, and over- or under-expression of TFHcell–associated molecules such as ICOS or IL-21, most likely contributes to the pathogenesis of certain autoimmune diseases or immunodeficiencies.
The Health and Cost Benefits of Work Site Health-Promotion Programs
Authors: Goetzel Ron Z. , Ozminkowski Ronald J.
Published: January 2008

We review the state of the art in work site health promotion (WHP), focusing on factors that influence the health and productivity of workers. We begin by defining WHP, then review the literature that addresses the business rationale for it, as well as the objections and barriers that may prevent sufficient investment in WHP. Despite methodological limitations in many available studies, the results in the literature suggest that, when properly designed, WHP can increase employees' health and productivity. We describe the characteristics of effective programs including their ability to assess the need for services, attract participants, use behavioral theory as a foundation, incorporate multiple ways to reach people, and make efforts to measure program impact. Promising practices are noted including senior management support for and participation in these programs. A very important challenge is widespread dissemination of information regarding success factors because only ∼7% of employers use all the program components required for successful interventions. The need for more and better science when evaluating program outcomes is highlighted. Federal initiatives that support cost-benefit or cost-effectiveness analyses are stressed, as is the need to invest in healthy work environments, to complement individual based interventions.
Direct observation of failing fibers in muscles of dystrophic mice provides mechanistic insight into muscular dystrophy
Authors: Claflin Dennis R. , Brooks Susan V.
Published: January 2008

Duchenne muscular dystrophy is caused by the absence of the protein dystrophin. Dystrophin's function is not known, but its cellular location and associations with both the force-generating contractile core and membrane-spanning entities suggest a role in mechanically coupling force from its intracellular origins to the fiber membrane and beyond. We report here the presence of destructive contractile activity in lumbrical muscles from dystrophin-deficient ( mdx) mice during nominally quiescent periods following exposure to mechanical stress. The ectopic activity, which was observable microscopically, resulted in longitudinal separation and clotting of fiber myoplasm and was absent when calcium (Ca2+) was removed from the bathing medium. Separation and clotting of myoplasm were also produced in dystrophin-deficient muscles by local application of a Ca2+ ionophore to create membrane breaches in the absence of mechanical stress, whereas muscles from control mice tolerated ionophore-induced entry of Ca2+ without damage. These observations suggest a failure cascade in dystrophin-deficient fibers that 1) is initiated by a stress-induced influx of extracellular Ca2+, causing localized activation to continue after cessation of stimulation, and 2) proceeds as the persistent local activation, combined with reduced lateral mechanical coupling between the contractile core and the extracellular matrix, results in longitudinal separation of myoplasm in nonactivated regions of the fiber. This mechanism invokes both the membrane stabilization and the mechanical coupling functions frequently proposed for dystrophin and suggests that, whereas the absence of either function alone is not sufficient to cause fiber failure, their combined absence is catastrophic.