bluuebunny/crossref_metadata_2025 huggingface dataset:
A microscopic view on contact angle selection
Authors: Snoeijer Jacco H. , Andreotti Bruno
Published: May 2008

We discuss the equilibrium condition for a liquid that partially wets a solid on the level of intermolecular forces. By using a mean field continuum description, we generalize the capillary pressure from variation of the free energy and show at what length scale the equilibrium contact angle is selected. After recovering Young’s law for homogeneous substrates, it is shown how hysteresis of the contact angle can be incorporated in a self-consistent fashion. In all cases, the liquid-vapor interface takes a nontrivial shape, which is compared to models using a disjoining pressure.
Selective excitation of coupled CO vibrations on a dissipative Cu(100) surface by shaped infrared laser pulses
Authors: Tremblay Jean Christophe , Beyvers Stephanie , Saalfrank Peter
Published: May 2008

In a previous paper [Beyvers et al., J. Chem. Phys. 124, 234706 (2006)], the possibility to mode and state selectively excite various vibrational modes of a CO molecule adsorbed on a dissipative Cu(100) surface by shaped IR pulses was examined. Reduced-dimensionality models with stretching-only coordinates were employed to do so. This model is now extended with the goal to include rotational modes. First, we present an analysis of the bound states of the adsorbed CO molecule in full dimension; i.e., six-dimensional eigenstates are obtained by diagonalizing the six-dimensional Hamiltonian containing the semiempirical potential of Tully et al. [J. Vac. Sci. Technol. A 11, 1914 (1993)]. This is achieved by using a contracted iterative eigensolver based on the coupled two-term Lanczos algorithm with full reorthogonalization. Reduced-dimension subsystem eigenvectors are also computed and then used to study the selective excitation of the molecule in the presence of dissipation within the density matrix formalism for open systems. In the density matrix propagations, up to four degrees of freedom were included, namely, r (the C–O distance), Z (the molecule-surface distance), and ϕ and θ (the azimuthal and polar angles of the molecular axis with respect to the surface). Short, intense laser pulses are rationally engineered and further refined with optimal control theory, again with the goal for mode and state selective excitation. Also, IR-laser induced desorption is studied. For the calculations, the previous two-mode (r,Z) dipole surface is extended to include the angular dependence and the model for the coupling of the molecule to the surface electronic degrees of freedom is refined.
Room temperature terahertz quantum cascade laser source based on intracavity difference-frequency generation
Authors: Belkin Mikhail A. , Capasso Federico , Xie Feng , Belyanin Alexey , Fischer Milan , Wittmann Andreas , Faist Jérôme
Published: May 2008

We report on our progress in the development of a terahertz quantum cascade laser source based on intracavity terahertz difference-frequency mixing in a dual-wavelength mid-infrared quantum cascade laser with the active region engineered to possess giant second-order nonlinear susceptibility. In this letter, we demonstrate devices that operate in mid-infrared at λ1=8.9μm and λ2=10.5μm and produce terahertz output at λ≈60μm via difference-frequency generation with 7μW output power at 80K, 1μW output at 250K, and still approximately 300nW output at 300K.
Entropy of water calculated from harmonic approximation: Estimation of the accuracy of method
Authors: Zielkiewicz Jan
Published: May 2008

Some molecular dynamics simulations were performed for liquid TIP4P and SPC water at a constant density (1.00g∕cm3) and within the temperature range of 5–90°C. By using harmonic approximation, both the entropy of water SH and the specific heat cv were calculated, and the results were compared to literature data. It was found that harmonic approximation overestimates absolute entropy of TIP4P water by 5.6J∕molK (∼9.5%) at 278K, but only by 0.4J∕molK (∼0.5%) at 363K. The value of the specific heat, however, is strongly underestimated: for TIP4P and SPC model, we obtain 59.5 and 56.9J∕molK using harmonic approximation, while the correct values are 79.0 and 72.3J∕molK, respectively.
Solution of a linearized model of Heisenberg’s fundamental equation II
Authors: Brüning E. , Nagamachi S.
Published: May 2008

We propose to look at (a simplified version of) Heisenberg’s fundamental field equation [see Heisenberg, W., Introduction to the Unified Field Theory of Elementary Particles (Wiley, New York, 1966)] as a relativistic quantum field theory with a fundamental length, as introduced by Brüning and Nagamachi [J. Math. Phys. 45, 2199 (2004)], and give a solution in terms of Wick power series of free fields which converge in the sense of ultrahyperfunctions but not in the sense of distributions. The solution of this model has been prepared by Nagamachi and Brüning [arXiv:0804.1663] by calculating all n-point functions by using path integral quantization. The functional representation derived in this part is essential for the verification of our condition of extended causality. The verification of the remaining defining conditions of a relativistic quantum field theory is much simpler through the use of Wick power series. Accordingly in this second part, we use Wick power series techniques to define our basic fields and derive their properties.
Reaction mechanisms during plasma-assisted atomic layer deposition of metal oxides: A case study for Al2O3
Authors: Heil S. B. S. , van Hemmen J. L. , van de Sanden M. C. M. , Kessels W. M. M.
Published: May 2008

Plasma-assisted atomic layer deposition (ALD) of metal oxide films is increasingly gaining interest, however, the underlying reaction mechanisms have rarely been addressed. In this work, a case study is presented for the plasma-assisted ALD process of Al2O3 based on Al(CH3)3 dosing and O2 plasma exposure. A complementary set of time-resolved in situ diagnostics was employed, including spectroscopic ellipsometry, quartz crystal microbalance, mass spectrometry, and optical emission spectroscopy. The saturation of the Al(CH3)3 adsorption reactions was investigated, as well as the reaction products created during both the precursor dosing and the plasma exposure step. The generality of the observations was cross-checked on a second commercial ALD reactor. The main observations are as follows: (i) during the precursor dosing, the Al(CH3)3 predominantly binds bifunctionally to the surface at 70°C through a reaction in which H is abstracted from the surface and CH4 is released into the gas phase; (ii) during the plasma exposure, O radicals in the plasma are consumed at the surface by combustionlike reactions with the surface −CH3 ligands, producing mainly H2O, CO2, and CO; (iii) small gas phase densities of CH4 and higher hydrocarbons (C2Hx) are also present during the O2 plasma exposure step indicating complementary surface reactions including a secondary thermal ALD-like reaction by the H2O produced at the surface; (iv) the plasma and its optical emission are strongly affected by the surface reaction products released in the plasma. In the latter respect, optical emission spectroscopy proved to be a valuable tool to study the surface reaction products during the plasma exposure as well as the saturation of the surface reactions. The implications of the experimental observations are addressed and it is discussed that the reaction mechanisms are generic for plasma-assisted ALD processes based on metal organic precursors and O2 plasma as oxidant source.
Light-induced detuning of a quartz crystal wafer with temperature-compensated cut
Authors: Zong Yun , Xu Fei , Su Xiaodi , Knoll Wolfgang
Published: May 2008

This paper reports the light-induced detuning effect of a quartz crystal wafer with a temperature-compensated cut. Upon incidence of light on its front electrode, the crystal wafer displays a reversible increase in the resonant frequency. The amplitude of this frequency increase is found to be light wavelength dependent and proportional to the light intensity. A larger frequency increase will be visible if the electrode is coated with materials of higher absorbance or is in contact to media of lower thermal conductivity, which points to a thermal nature of the effect. If a p-polarized laser beam is incident on the quartz crystal wafer bearing a gold grating electrode, the photon energy can possibly be coupled into the electrode via the resonant excitation of a surface plasmon mode. There, a strict correlation is found between the amplitude of the detuned resonant frequency and the intensity loss in the surface plasmon resonance reflectivity signals. This correlation allows for the integration of a surface plasmon grating coupler in a quartz crystal microbalance in a very simple configuration.
Ex situ doping of silicon nanowires with boron
Authors: Ingole S. , Aella P. , Manandhar P. , Chikkannanavar S. B. , Akhadov E. A. , Smith D. J. , Picraux S. T.
Published: May 2008

An ex situ proximity technique is demonstrated for the electrical doping of silicon nanowires with spin on dopant (SOD) used as the boron source. The technique is based on solid-state diffusion and is comprised of two stages: predeposition and drive in. During predeposition, a predetermined amount of boron is introduced into the near surface region of the nanowires by holding the SOD source in close proximity to the nanowires. The boron concentration in the nanowires is controlled by the appropriate selection of predeposition temperature and time, with 800 and 950 °C and 5–10 min used in the present studies. The boron is then diffused further into the nanowires during the drive-in stage. The doped nanowires were characterized using scanning electron microscopy, secondary ion mass spectrometry, transmission electron microscopy, and four-probe electrical transport measurements. The high temperatures employed in this doping process do not result in any observable damage to these 120–180 nm diameter nanowires and good control over the dopant concentration in the range from 1018 to 1020 cm−3 is obtained. This ex situ doping technique provides a useful alternative to the methods currently available for electrical doping of nanowires, which are predominantly in situ techniques.
Circular dichroism spectroscopy of small molecular aggregates: Dynamical features and size effects
Authors: Seibt Joachim , Dehm Volker , Würthner Frank , Engel Volker
Published: May 2008

Circular dichroism (CD) spectra of small molecular aggregates, taking monomer vibrational motion into account, are calculated by employing wave packet propagation techniques. The spectra are related to the population and exciton transfer in the aggregates. It is investigated as to how far this dynamics can be directly extracted from the CD spectra. The method is applied to aggregates of perylene bisimides where temperature dependent spectra have recently been recorded in our laboratory [V. Dehm et al., Org. Lett. 9, 1085 (2007)].
The positive bias temperature instability of n-channel metal-oxide-semiconductor field-effect transistors with ZrO2 gate dielectric
Authors: Hsu De-Cheng , Chang Ingram Yin-ku , Wang Ming-Tsong , Juan Pi-Chun , Wang Y. L. , Lee Joseph Ya-min
Published: May 2008

The positive bias temperature instability of n-channel metal-oxide-semiconductor field-effect transistors with ZrO2 gate dielectric was studied. It was observed that the degradation in threshold voltage (ΔVT) has an exponential dependence on the stress time in the temperature range from 25to75°C. The measurement of subthreshold slope (ΔS) during stress indicates that the degradation in VT is due to the interface trap charges Qit. The extracted activation energy of 0.3–0.5eV is related to a degradation dominated by the release of atomic hydrogen in the Si–ZrO2 interface.
An efficient algorithm for solving nonlinear equations with a minimal number of trial vectors: Applications to atomic-orbital based coupled-cluster theory
Authors: Ziółkowski Marcin , Weijo Ville , Jørgensen Poul , Olsen Jeppe
Published: May 2008

The conjugate residual with optimal trial vectors (CROP) algorithm is developed. In this algorithm, the optimal trial vectors of the iterations are used as basis vectors in the iterative subspace. For linear equations and nonlinear equations with a small-to-medium nonlinearity, the iterative subspace may be truncated to a three-dimensional subspace with no or little loss of convergence rate, and the norm of the residual decreases in each iteration. The efficiency of the algorithm is demonstrated by solving the equations of coupled-cluster theory with single and double excitations in the atomic orbital basis. By performing calculations on H2O with various bond lengths, the algorithm is tested for varying degrees of nonlinearity. In general, the CROP algorithm with a three-dimensional subspace exhibits fast and stable convergence and outperforms the standard direct inversion in iterative subspace method.
Comparative study of electroabsorption in InGaN∕GaN quantum zigzag heterostructures with polarization-induced electric fields
Authors: Sari Emre , Ozel Tuncay , Koc Aslı , Ju Jin-Woo , Ahn Haeng-Keun , Lee In-Hwan , Baek Jong-Hyeob , Demir Hilmi Volkan
Published: May 2008

We present a comparative study on InGaN∕GaN quantum zigzag structures embedded in p-i-n diode architecture that exhibit blue-shifting electroabsorption in the blue when an electric field is externally applied to compensate for the polarization-induced electric field across the wells. With the polarization breaking their symmetry, the same InGaN∕GaN quantum structures redshift their absorption edge when the external field is applied in the same direction as the well polarization. Both computationally and experimentally, we investigate the effects of polarization on electroabsorption by varying compositional content and structural parameters and demonstrate that electroabsorption grows stronger with weaker polarization in these multiple quantum well modulators.
Room temperature ferromagnetism in diluted magnetic semiconductor Zn1−xCrxTe nanoparticles synthesized by chemical method
Authors: Niwayama Yutaka , Kura Hiroaki , Sato Tetsuya , Takahashi Migaku , Ogawa Tomoyuki
Published: May 2008

Nanoparticles of diluted magnetic semiconductor Zn1−xCrxTe with various Cr concentrations were synthesized by a chemical method, and their magnetic properties were investigated. The synthesized nanoparticles show ferromagnetism, and the saturation magnetization increased with increasing Cr concentration in the range from x=0.002tox=0.02. The Zn0.98Cr0.02Te nanoparticles showed ferromagnetism above room temperature, where the Curie temperature TC was estimated to be about 520K. This is much higher than the reported value of TC in the Zn1−xCrxTe thin films.
Wavelength selective coupler with vertical gratings on silicon chip
Authors: Ikeda Kazuhiro , Nezhad Maziar , Fainman Yeshaiahu
Published: May 2008

We propose a wavelength selective coupler using vertical grating structure on silicon chip and discuss the operation principle and the analytic design procedure. The transmission spectra expected by the procedure agree with finite difference time domain simulation results. We then fabricate the designed wavelength selective coupler and demonstrate the expected operation. The available wavelength-division-multiplexing bandwidth of this device is not limited by free spectral range as in ring resonators. We also propose some applications of the wavelength selective coupler.
The toad ahead: challenges of modelling the range and spread of an invasive species
Authors: Phillips Benjamin L. , Chipperfield Joseph D. , Kearney Michael R.
Published: May 2008

An ability to predict the rate at which an organism spreads its range is of growing importance because the process of spread (during invasion by an exotic species) is almost identical to that occurring at the expanding range margins of a native species undergoing range shifts in response to climate change. Thus, the methods used for modelling range spread can also be employed to assess the distributional implications of climate change. Here we review the history of research on the spread of cane toads in Australia and use this case study to broadly examine the benefits and pitfalls of various modelling approaches. We show that the problems of estimating the current range, predicting the future range, and predicting the spread rate are interconnected and inform each other. Generally, we argue that correlative approaches to range-prediction are unsuitable when applied to invasive species and suggest that mechanistic methods are beginning to look promising (despite being more difficult to execute), although robust comparisons of correlative versus mechanistic predictions are lacking. Looking to the future, we argue that mechanistic models of range advance (drawing from both population ecology and environmental variation) are the approaches most likely to yield robust predictions. The complexity of these approaches coupled with the steady rise in computing power means that they have only recently become computationally tractable. Thus, we suggest that the field is only recently in a position to incorporate the complexity necessary to robustly model the rate at which species shift their range.
The genetics of mammalian invasions: a review
Authors: Searle Jeremy B.
Published: May 2008

This review takes a broad perspective on mammalian invasions and considers genetic aspects of both natural colonisation and conservation-related translocations as a backdrop to the genetics of introductions of wildlife-management concern. Genetics can help characterise invading populations in useful ways and can reveal, with greater or lesser precision, the geographical sources of invasions, their timing and how many individuals were involved. Invading mammals may affect the genetics of natives indirectly or directly, and it is important to be able to document this. There is a need to consider both ‘organism invasion’ and ‘gene invasion’. Genetics often provides an unexpected perspective on invasion biology. Examples illustrating all these points are provided through the article.
Automatic Time–Motion Study of a Multistep Preoperative Process
Authors: Meyer Mark A. , Seim Andreas R. , Fairbrother Pamela , Egan Marie T. , Sandberg Warren S.
Published: May 2008

Background

Hospitals use time-motion studies to monitor process effectiveness and patient waiting. Manual tracking is labor-intensive and potentially influences system performance. New technology known as indoor positioning systems (IPS) may allow automatic monitoring of patient waiting and progress. The authors tested whether an IPS can track patients through a multistep preoperative process.

Methods

The authors used an IPS between October 14, 2005, and June 13, 2006, to track patients in a multistep ambulatory preoperative process: needle localization and excisional biopsy of a breast lesion. The process was distributed across the ambulatory surgery and radiology departments of a large academic hospital. Direct observation of the process was used to develop a workflow template. The authors then developed software to convert the IPS data into usable time-motion data suitable for monitoring process efficiency over time.

Results

The authors assigned tags to 306 patients during the study period. Eighty patients never underwent the procedure or never had their tag affixed. One hundred seventy-seven (78%) of the remaining 226 patients successfully matched the workflow template. Process time stamps were automatically extracted from the successful matches, measuring time before radiology (mean +/- SD, 77 +/- 35 min), time in radiology (105 +/- 35 min), and time between radiology and operating room (80 +/- 60 min), which summed to total preoperative time (261 +/- 67 min).

Conclusions

The authors have demonstrated that it is possible to use a combination of IPS technology and sequence alignment pattern matching software to automate the time-motion study of patients in a multidepartment, multistep process with the only day-of-surgery intervention being the application of a tag when the patient arrives.
Anesthetic Propofol Enhances Plasma γ-Tocopherol Levels in Patients Undergoing Cardiac Surgery
Authors: Cavalca Viviana , Colli Susanna , Veglia Fabrizio , Eligini Sonia , Zingaro Lorenzo , Squellerio Isabella , Rondello Nicola , Cighetti Giuliana , Tremoli Elena , Sisillo Erminio
Published: May 2008

Background

Propofol (2,6-diisopropylphenol) is an anesthetic drug with antioxidant and antiinflammatory properties, documented both in vitro and in experimental models of ischemia-reperfusion injury and septic shock. These properties have been related to the similarity of its chemical structure to that of endogenous tocopherols, which are phenol-containing radical scavengers. This study evaluated the effects of propofol on alpha- and gamma-tocopherol (alpha- and gamma-T) levels and on selected markers of oxidant-antioxidant and inflammatory status in patients undergoing cardiac surgery.

Methods

Patients were randomly assigned for anesthesia with either propofol (propofol group, n = 22) or sevoflurane (control group, n = 21). Plasma levels of alpha- and gamma-T, individual antioxidant capacity, malondialdehyde, and interleukin 10 were measured before, during, and after anesthesia. In addition, levels of the proinflammatory prostaglandin E2 as a marker of cyclooxygenase-2 activity and those of interleukin 10 were measured in whole blood cultured with bacterial lipopolysaccharide.

Results

Gamma-T levels increased significantly during surgery in propofol group (P < 0.0001 vs. control group). By contrast, alpha-T similarly decreased in both groups. Malondialdehyde and interleukin 10 increased markedly and individual antioxidant capacity decreased, without differences between groups. Prostaglandin E2 levels measured 24 h after anesthesia induction were significantly lower in the propofol than in the control group. In vitro studies highlighted the different capacity of gamma- and alpha-T to impair prostaglandin E2 synthesis by human monocytes challenged with bacterial lipopolysaccharide.

Conclusions

The antiinflammatory properties of propofol that may be linked to its effect on gamma-T levels could be relevant in controlling the inflammatory response that accompanies tissue injury during reperfusion.
Nasal Ventilation Is More Effective than Combined Oral–Nasal Ventilation during Induction of General Anesthesia in Adult Subjects
Authors: Liang Yafen , Kimball William R. , Kacmarek Robert M. , Zapol Warren M. , Jiang Yandong
Published: May 2008

Background

The authors hypothesized that nasal mask ventilation may be more effective than combined oral-nasal mask ventilation during induction of general anesthesia. They tested this hypothesis by comparing the volume of carbon dioxide removed per breath with nasal versus combined oral-nasal mask ventilation in nonparalyzed, apneic, adult subjects during induction of general anesthesia.

Methods

Fifteen adult subjects receiving general anesthesia were ventilated first with a combined oral-nasal mask and then with only a nasal mask. The patient's head was maintained in a neutral position, without head extension or lower jaw thrust. Respiratory parameters were recorded simultaneously from both the nasal and oral masks regardless of ventilation approach.

Results

The volume of carbon dioxide removed per breath during nasal mask ventilation (median, 5.0 ml; interquartile range, 3.4-8.8 ml) was significantly larger than that during combined oral-nasal mask ventilation (median, 0.0 ml; interquartile range, 0.0-0.4 ml; P = 0.001); even the peak inspiratory airway pressure during nasal ventilation (16.7 +/- 2.7 cm H2O) was lower than that during combined oral-nasal ventilation (24.5 +/- 4.7 cm H2O; P = 0.002). The expiratory tidal volume during nasal ventilation (259.8 +/- 134.2 ml) was also larger than that during combined oral-nasal ventilation (98.9 +/- 103.4 ml; P = 0.003).

Conclusions

Nasal mask ventilation was more effective than combined oral-nasal mask ventilation in apneic, nonparalyzed, adult subjects during induction of general anesthesia. The authors suggest that nasal mask ventilation, rather than full facemask ventilation, be considered during induction of anesthesia.
The dynamics of bottom–up and top–down control in a New England salt marsh
Authors: Sala N. M. , Bertness M. D. , Silliman B. R.
Published: May 2008

Traditionally, salt marsh ecosystems were thought to be controlled exclusively by bottom–up processes. Recently, this paradigm has shifted to include top–down control as an additional primary factor regulating salt‐marsh community structure. The most recent research on consumer impacts in southern US marshes has shown that top–down forces often interact with biotic and abiotic factors, such as secondary fungal infection in grazer‐induced wounds, soil nutrients and climatic variation, to influence ecosystem structure. In a more northern salt marsh, located in New England, we examined the separate and interactive effects of nutrient availability, insect herbivory and secondary fungal infection, on growth of the foundation species, Spartina alterniflora. We used a factorial design with two levels of nutrients (control and addition) insects (control and removal) and fungi (control and removal). Nutrient addition increased plant biomass by 131% in the absence of herbivores. When insect consumers were allowed access to fertilized plots, biomass was reduced by nearly 45% when compared with treatments with nutrients and insecticide. In contrast, insect herbivores did not affect plant biomass in unfertilized control treatments. These differences suggest that consumer effects are triggered under high nutrient levels only. We also found that secondary fungal infections in grazer‐induced wounds, in contrast to lower latitude marshes, did not significantly impact primary production. Our results suggest that while New England salt marshes may typically be under bottom–up control, eutrophication can trigger dual control with inclusion of top–down regulation. However, unlike lower latitude marshes, consumer control of plant growth in northern US salt marshes is not dependent on herbivores facilitating fungal infections that then control grass growth, suggesting that the intensity of disease mediated top–down control by small grazers may be regulated by climate and/or grazer identity that co‐vary with latitude.
The spatial distribution of badgers, setts and latrines: the risk for intra‐specific and badger‐livestock disease transmission
Authors: Böhm Monika , Palphramand Kate L. , Newton‐Cross Geraldine , Hutchings Michael R. , White Piran C. L.
Published: May 2008

The spatial distribution of wildlife hosts and the associated environmental distribution of their excretory products are important factors associated with the risk of disease transmission between wildlife and livestock. At a landscape scale, heterogeneous distribution of a wildlife host will create regional hot spots for disease risk, while at the farm level, distributional patterns of wildlife excretory products as well as habitat use are of primary importance to the assessment of disease risk to livestock. In the UK, badgers have been implicated in the transmission of bovine tuberculosis to cattle. In this study, we focus on the spatial and social organization and habitat use of badgers as well as the distributions of their excretions at latrine and sett sites to assess intra‐ and inter‐species (badger–cattle) disease risk. Across the study site, badger latrines and setts were found in prominent clusters, at distances of up to 250 and 200 m respectively. This was partly due to small‐scale clustering of latrines around sett sites, so that disease risk may be higher within the vicinity of setts. The clustered distribution suggests that sites of high risk for TB transmission may be localised within farms. Exclusion of cattle from the few sett and latrine sites within their grazing pasture is therefore likely to provide an effective way of reducing the risk of disease transmission. We also found evidence of social sub‐division within badger social groups based on differences in the use of main and outlier setts. This may contribute to localised clusters of infection within the badger population, resulting in heterogeneous patterns of environmental disease risk to the wider host community. A greater understanding of variation in host behaviour and its implications for patterns of disease will allow the development of more targeted and effective management strategies for wildlife disease in group‐living hosts.
Geographic variation in seed removal of a myrmecochorous herb: influence of variation in functional guild and species composition of the disperser assemblage through spatial and temporal scales
Authors: Manzaneda Antonio J. , Rey Pedro J.
Published: May 2008

The ecological influence of changes in the functional guild and species composition of ant assemblages on ant‐dispersal mutualisms is still poorly known. Using a multi‐scale approach over an 800 km range within the Iberian Peninsula, we tested the hypothesis that variation in seed removal rate was related to functional guild rather than to species composition variations of disperser assemblages in the myrmecochore herb Helleborus foetidus. At least two premises must be confirmed to validate this hypothesis: 1) ant assemblages that are dissimilar in species composition but with similar functional guild composition will not differ significantly in seed removal, and 2) assemblages with different functional guild composition will render different seed removal services. We conducted 3328 ant‐visitor censuses on 462 individual plants to identify both the species composition and functional guild variation of the ant‐disperser assemblage, and the plant seed removal rate. Functional guild composition of the ant assemblage was determined by the proportion of visits of ants acting as legitimate dispersers, facultative dispersers or elaiosome predators. Results showed that ant‐seed dispersal success seemed to be more sensitive to species composition changes of the ant assemblage than to functional guild shifts. However, this sensitivity was scale‐dependent. Thus, at the fine, inter‐individual scale, seed removal covaried with the species and functional guild composition of the ant assemblages; at the inter‐populational scale, differences in seed removal tended to be related to the dissimilarity of the assemblage species composition rather than the assemblage functional guild; finally, inter‐regional differences in seed removal were unrelated to dissimilarities of the ant assemblage composition or functional guild. Though differences in seed removal and the relative frequency of the legitimate dispersers tended to be positively correlated, none of the above premises were fully confirmed in this study. Therefore, our results did not support in full the hypothesis that the variation in seed removal was explained by shifts in functional guild composition, rather than shifts in species composition.
Functional roles of N‐glycans in cell signaling and cell adhesion in cancer
Authors: Zhao Yan‐Yang , Takahashi Motoko , Gu Jian‐Guo , Miyoshi Eiji , Matsumoto Akio , Kitazume Shinobu , Taniguchi Naoyuki
Published: May 2008

Glycosylation is one of the most common post‐translational modification reactions and nearly half of all known proteins in eukaryotes are glycosylated. In fact, changes in oligosaccharide structures are associated with many physiological and pathological events, including cell growth, migration, differentiation, tumor invasion, host–pathogen interactions, cell trafficking, and transmembrane signaling. Emerging roles of glycan functions have been highly attractive to scientists in various fields of life science as they open a field, “Functional Glycomics”, that is a comprehensive study of the glycan structures in relation to functions. In particular, the N‐glycans of signaling molecules including receptors or adhesion molecules are considered to be involved in cellular functions. This review will focus on the roles of glycosyltransferases involved in the biosynthesis of N‐glycan branching and identification of cell surface receptors as their target proteins. We also suggest that the modulation of N‐glycans of those receptors alters their important functions such as cell signaling and cell adhesion which are implicated in cancer invasion and metastasis. (Cancer Sci 2008; 99: 1304–1310)
Report of a workshop on malignant lymphoma: a review of molecular and clinical risk profiling
Authors: Gleissner B. , Küppers R. , Siebert R. , Glass B. , Trümper L. , Hiddemann W. , Dreyling M.
Published: May 2008

Molecular genetic analysis adds important information for lymphoma biology and classification, but the latter is challenged by recent improvement of combined chemo‐immunotherapy. In aggressive lymphoma, molecular profiling identifies risk groups with certain genetic background but still the International Prognostic Index (IPI) remains the most important clinically applicable predictor of outcome. In follicular lymphoma (FL), the importance of the meshwork of bystander cells becomes increasingly evident. As combined immuno‐chemotherapy improved the prognosis of the patients, several clinical trials indicated that the FLIPI still efficiently discriminates patients at risk for transformation and relapse, although several mechanisms of transformation seem to exist. In mantle cell lymphoma it has been proven that pathogenesis and prognosis mainly depend on deregulation of the cell cycle. A reliable clinical risk score could be established.
CD66a (CEACAM1) expression by mouse natural killer cells
Authors: Thirion Gaëtan , Feliu Ana Agusti , Coutelier Jean‐Paul
Published: May 2008

CD66a (CEACAM1), an adhesion molecule that has regulatory function on T lymphocytes, was found to be expressed on a minority of mouse natural killer (NK) cells, especially in the liver. CD66a expression on NK cells depended on their differentiation stage, with highest levels on immature CD49b−NK cells. Expression of CD66a on NK cells was strongly enhanced by in vitro activation with interleukin‐12 (IL‐12) and IL‐18. However, in vivo NK cell stimulation by infection with lactate dehydrogenase‐elevating virus did not lead to strong CD66a expression, even on activated interferon‐‐γ‐producing NK cells. These results indicate that CD66a expression is differently regulated, depending on the NK cell activation pathway, which may lead to distinct regulatory mechanisms of the functional subpopulations of these cells.
Oral infections in immunocompromised patients
Authors: Heimdahl Anders , Nord Carl Erik
Published: May 2008

Abstract. The number of immunocompromised patients has increased during recent years, mainly because of more aggressive anti‐cancer treatment and increased survival periods for end‐stage cancer patients. Congenital and acquired immunodeficiencies are also more frequently recognized in dental practice due to increased diagnostic knowledge and increased numbers of HIV‐infected persons. Oral complications and infections are related to the type and severeness of the immunodeficiency. Low amounts of immunoglobulins are known to play a role in many bacterial infections, e.g., upper respiratory tract infections, but have not yet been associated with specific oral conditions. T‐cell defects tend to increase suspectibility towards oral infections with fungi and virus, and are also associated with periodontal disease in HIV‐infected patients. Defects in the phagocytic system increase the risk of periodontal disease in certain patient groups. Severe granulocytopenia as observed, e.g., in leukemic patients increases the risk of septicemia with oral micro‐organisms.
Oral infections related to radiation and immunosuppressive therapy
Authors: Nikoskelainen Jukka
Published: May 2008

Abstract. The frequency of oral infection complications after cytotoxic chemotherapy andradiochemotherapy is significant, often contributing to serious septic infectious complications. Generally, the more intense the cytotoxic therapy, the more common are the oral infection complications. In the present review, the spectrum of oral infections related to radiation and immunosuppressive therapy are evaluated and the different local and systemic treatment modalities are presented.
Daytime sleepiness and neural cardiac modulation in sleep‐related breathing disorders
Authors: LOMBARDI CAROLINA , PARATI GIANFRANCO , CORTELLI PIETRO , PROVINI FEDERICA , VETRUGNO ROBERTO , PLAZZI GIUSEPPE , VIGNATELLI LUCA , DI RIENZO MARCO , LUGARESI ELIO , MANCIA GIUSEPPE , MONTAGNA PASQUALE , CASTIGLIONI PAOLO
Published: May 2008

Sleep‐related breathing disorders are common causes of excessive daytime sleepiness, a socially and clinically relevant problem. Mechanisms responsible for daytime sleepiness are still largely unknown. We investigated whether specific alterations in autonomic cardiac modulation during sleep, commonly associated with sleep‐related breathing disorders, are related to excessive daytime sleepiness. Fifty‐three patients with sleep‐related breathing disorders underwent nocturnal polysomnography. Excessive daytime sleepiness was diagnosed as a Multiple Sleep Latency Test response less than or equal to 600 s. We explored the relation of excessive daytime sleepiness, objectively determined, with indices of autonomic cardiac regulation, such as baroreflex sensitivity and heart rate variability, with polysomnographic indices of the severity of sleep‐related breathing disorders and with quality of sleep. Patients with excessive daytime sleepiness, when compared with patients without, had significantly lower baroreflex sensitivity and significantly higher low‐to‐high frequency power ratio of heart rate variability during the different stages of nocturnal sleep. By contrast, no differences were found in indices quantifying the severity of sleep‐related breathing disorders or sleep quality. We demonstrated that excessive daytime sleepiness is accompanied by a deranged cardiac autonomic control at night, the latter probably reflecting autonomic arousals not detectable in the EEG. As abnormal autonomic regulation is also known to be associated with increased cardiovascular risk, a possible relation between excessive daytime sleepiness and cardiovascular events in patients with sleep‐related breathing disorders deserves to be investigated in future studies.
Leukotriene inhibition in small animal medicine
Authors: GOODMAN L. , COLES T. B. , BUDSBERG S.
Published: May 2008

Leukotrienes are important mediators of inflammatory and allergic conditions in people and are suspected to play an important role in tumorigenesis and tumor growth of several different tumor types. Based on this, researchers are making great progress in identifying novel pharmacologic targets for several human diseases. Leukotriene inhibition has resulted in therapeutic benefit in clinical trials involving people with osteoarthritis, allergic asthma, and atopic dermatitis. Despite this progress and the possibility that leukotriene inhibition may also play an important therapeutic role in veterinary patients, parallel advances have not yet been made in veterinary medicine. This article summarizes leukotriene function and synthesis. It also reviews the published literature regarding potential therapeutic applications of leukotriene inhibition in both human and veterinary medicine, focusing primarily on osteoarthritis, NSAID induced gastrointestinal mucosal damage, allergic asthma, atopic dermatitis, and cancer.
Pharmacokinetics of lidocaine following the application of 5% lidocaine patches to cats
Authors: KO J. C. H. , MAXWELL L. K. , ABBO L. A. , WEIL A. B.
Published: May 2008

Lidocaine patches have been used to provide local analgesia in dogs and cats. We conducted this study to assess the systemic and local absorption of lidocaine from topical patches in cats. Eight 2‐year‐old cats received either intravenous lidocaine at 2 mg/kg or one 700 mg lidocaine patch placed on the lateral thorax for 72 h, in a cross‐over randomized repeated measures design. Plasma was collected at specific times and the skin was biopsied at the time of patch removal for the quantitative analysis of lidocaine and its major metabolite, monoethylglycinexylidide (MEGX), by gas chromatography with mass spectrometry. Percent absorption time plots for systemic lidocaine appearance were constructed using the Loo‐Riegelman method. Approximately, constant rate absorption was observed from 12–72 h after patch application at a mean ± SD rate of 109 ± 49 μg/kg/h, resulting in steady‐state lidocaine plasma concentrations of 0.083 ± 0.032 μg/mL and MEGX concentrations of 0.012 ± 0.009 μg/mL. Overall bioavailability of transdermal lidocaine was 6.3 ± 2.7%, and only 56 ± 29% of the total lidocaine dose delivered by the patch reached systemic circulation. Skin lidocaine concentrations were much higher than plasma concentrations, at 211 ± 113 μg/g in the thoracic skin beneath the patch and 2.2 ± 0.6 μg/g in the contralateral thoracic skin without the patch. As both lidocaine and MEGX were recovered from contralateral skin, it is likely that lidocaine accumulated in the skin from low systemic concentrations of circulating lidocaine over the 72‐h period of patch application. Plasma lidocaine concentrations remained well below systemically toxic concentrations, and no obvious clinical side effects were observed in any of the cats. The low systemic absorption rate coupled with high local lidocaine concentrations on the skin support the safe use of lidocaine patches in cats.
Associations of birthweight and infant growth with body composition at age 15 – the COMPASS study
Authors: Eriksson Marit , Tynelius Per , Rasmussen Finn
Published: May 2008

Size at birth and postnatal growth have been positively associated with obesity in adulthood. However, associations between postnatal growth and body composition later in life have rarely been studied. The overall purpose was to explore the associations between birthweight, weight gain during first year of life and height, weight, body mass index, fat free mass index (FFMI), fat mass index, % fat mass (FM) and waist circumference in adolescence.

The COMPASS study is a population‐based study of adolescents from a well‐defined area in Stockholm County, Sweden. Birth characteristics and weight during childhood were collected from registers and child health centre records, and body composition at age 15 years was measured by bioelectric impedance by trained nurses. Complete data were available for 2453 adolescents. Associations between predictor and outcome variables were assessed with linear regression modelling.

Birthweight was positively associated with all outcome variables, except for %FM among girls. FFMI increased by 0.49 kg/m2[95% CI 0.34, 0.63] (boys) and 0.25 kg/m2[0.12, 0.38] (girls) per 1 SD increase in birthweight. Increased weight gain in infancy showed strong, positive associations with all measures of body composition. FFMI increased by 0.73 kg/m2[0.60, 0.87] (boys) and 0.63 kg/m2[0.50, 0.76] (girls) per unit increase in weight z‐score during first year of life. The effect of increased weight gain in infancy was not modified by birthweight. Birthweight and postnatal growth were both positively related to body composition in adolescence. Increased weight gain during the first year of life had stronger effect than prenatal growth, suggesting infancy to be a more critical period.
Ethnic differences in term birthweight: the role of constitutional and environmental factors
Authors: Goedhart Geertje , Van Eijsden Manon , Van Der Wal Marcel F. , Bonsel Gouke J.
Published: May 2008

It is not clear to what extent ethnic differences in the term birthweight distribution are constitutional or pathological. This study explored term birthweight heterogeneity between ethnic groups and the explanatory role of constitutional and environmental factors. As part of a prospective cohort study, the Amsterdam Born Children and their Development study, 8266 pregnant women filled out a questionnaire during early pregnancy. Ethnic groups were categorised as: native Dutch group; first and second generation Surinamese, Antillean, Turkish, Moroccan, Ghanaian and other non‐Dutch groups. Only singleton livebirths with ≥37.0 weeks of gestation and with complete data were included for analysis (n = 7118). We performed linear regression analyses to estimate the association between ethnicity and, for gestational age, standardised birthweight at term, adjusted for constitutional (fetal gender, parity, maternal age, maternal height) and environmental (education, cohabitation status, maternal body mass index, smoking, alcohol consumption, depression, work stress) determinants respectively.

Mean birthweight ranged from 3223 g (second generation Surinamese newborns) to 3548 g (Dutch newborns). Adjustment for constitutional factors substantially reduced the ethnic differences in birthweight, while adjustment for environmental factors provided little additional explanation. Surinamese [first generation: regression coefficient (b) = −98.3 g, P < 0.001; second generation: b = −159.3 g, P < 0.001], first generation Antillean (b = −102.0 g, P = 0.037), and Ghanaian newborns (b = −120.7 g, P = 0.001) remained significantly smaller than Dutch newborns after adjustment for all determinants. Term birthweight differences between Dutch newborns and Turkish, Moroccan and other non‐Dutch newborns were largely explained by constitutional rather than environmental determinants, limiting the need for prevention. Surinamese, Antillean and Ghanaian (mainly black) newborns remained unexplainably smaller after adjustment, leaving the possibility of either unknown constitutional or pathological underlying mechanisms.
Palaeoenvironmental significance of Late Permian palaeosols in the South‐Eastern Iberian Ranges, Spain
Authors: DE LA HORRA RAÚL , BENITO Ma ISABEL , LÓPEZ‐GÓMEZ JOSE , ARCHE ALFREDO , BARRENECHEA JOSÉ F. , LUQUE JAVIER
Published: May 2008

The Late Permian (Wuchiapingian) Alcotas Formation in the SE Iberian Ranges consists of one red alluvial succession where abundant soil profiles developed. Detailed petrographical and sedimentological studies in seven sections of the Alcotas Formation allow six different types of palaeosols, with distinctive characteristics and different palaeogeographical distribution, to be distinguished throughout the South‐eastern Iberian Basin. These characteristics are, in turn, related to topographic, climatic and tectonic controls. The vertical distribution of the palaeosols is used to differentiate the formation in three parts from bottom to top showing both drastic and gradual vertical upwards palaeoenvironmental changes in the sections. Reconstruction of palaeoenvironmental conditions based on palaeosols provides evidence for understanding the events that occurred during the Late Permian, some few millions of years before the well‐known Permian‐Triassic global crisis.