bluuebunny/crossref_metadata_2025 huggingface dataset:
On the Adult Morphology of Wuchereria sp. (malayi?) from a Monkey (Macaca irus) and from Cats in Malaya, and on Wuchereria pahangi n.sp. from a Dog and a Cat
Authors: Buckley J. J. C. , Edeson J. F. B.
Published: November 2009

Adult specimens or parts of specimens of Wuchereria were recovered from the lymphatic systems of a Kra monkey (Macaca irus) (1), domestic cats (4), a dog (1) and a Slow Loris (N. coucang), from areas of endemic human filariasis in Pahang, Malaya.

Morphological studies on this material revealed a new species, herein named W. pahangi, in the dog and in one cat; a species in the Kra monkey which is close to and probably identical with adults of W. malayi as described by Bonne el at. (1941) from man in Indonesia; but its relationships, and also those of the species from man in Indonesia, with the W. malayi described by Rao & Maplestone (1939) in India need further investigation. Three cats harboured a species which is close to that in the Kra monkey but its identity is sub judice until further material is available. Fragments only of a female worm, which included the tail, were recovered from the Slow Loris. It is thought that this material may be the new species W. pahangi.
Studies on Anafilaroides rostratus Gerichter, 1949 in Cats: II. The Life Cycle
Authors: Seneviratna P.
Published: November 2009

The first stage larva of Anafilaroides rostratus develops, after penetration into the foot of certain molluscs, Laevicaulis alte Fer. Mariella dussumieri Gray, Achatina fulica (Fer.) and Helix aspersa Müller. Two moults occur in the foot of these molluscs in 20–56 days depending on the temperature. After each moult the cuticle is shed. The details of development are described. The infective larvae are found in the foot of these molluscs. Natural infection was found in L. alte.

Mice and chickens can act as auxiliary hosts. Probably rats, other rodents and birds can also act in the same capacity.

The study of the development of the parasite in the cats is not complete. On ingestion the infective larvae penetrate the stomach wall and reach the lung where the third and the fourth moults occur. Exact times of the occurrence of the moults have not been definitely established. All moults are however completed by the 46th day; from then until the 58th day, immature helminths are found in the lungs. Fully gravid females are found on the 74th day, and larvae are first seen on the 78th day. The worms continue to produce larvae for more than 255 days after maturity. The duration of the life of the adult is probably considerably longer than one year.
Observations on Microfilaria fijiensis Yeh, Symes and Mataika, 1958 from Fruit Bats (Pteropus hawaiiensis) in Fiji
Authors: Symes C. B. , Mataika J. U.
Published: November 2009

During the course of studies on human filariasis in Fiji in the period 1954–50, two new microfilariae were found in fruit bats. The first was found in the blood of 38 bats out of 111 examined from various islands of the territory. It has recently been described and named Microfilaria fijiensis by Yeh, Symes and Mataika (1958).
A Modified Technique for Preliminary Screening of Compounds for Anthelmintic Activity against Eggs and Larvae of Bursate Nematodes of Sheep
Authors: Parnell I. W.
Published: November 2009

A technique is described for measuring the larvicidal activity of compounds against the free-living stages of bursate nematodes of sheep. Cultures were made in small glass tubes in 2 oz. “pomade” jars, and the larvicidal effects of the compounds were measured by comparing the number of infective larvae which were recovered from treated cultures with the numbers from the control cultures.

This technique provides another in vitro screening method for compounds which may be effective as anthelmintics against bursate nematodes.
The Development and Life History of Echinorhynchus truttae Schrank, 1788 (Acanthocephala)
Authors: Awachie J. B. E.
Published: November 2009

The details of the post-embryonic development of Echinorhynchus truttae in the intermediate host, Gammarus pulex, and the final host, Salmo truttae, are described.

The cystacanths of this species are sexually mature and are formed about 82 days after infection at room temperature, ca. 17°C.

Copulation takes place in the definitive host soon after the worms enter the pyloric region of the intestine. About 10 weeks after infection, mature eggs are passed out with the faeces of fish.
The Intermediate Host and the Cercaria of Gastrodiscoides hominis (Trematoda: Gastrodiscidae). Preliminary Report
Authors: Dutt S. C. , Srivastava H. D.
Published: November 2009

The planorbid snail Helicorbis coenosus (Benson) has been found experimentally to serve as the intermediate host of Gastrodiscoides hominis.

The cercaria of G. hominis is described. It is characterized by the presence of a pair of well-developed oral pouches, an alimentary tract having an oesophagus with a muscular bulb and two simple intestinal caeca, an excretory system with a cross-connection between the two main trunks and a reproductive system represented by rudimentary cell groups arranged in a manner similar to that found in the adult fluke.
Corynosoma strumosum (Rud.) and C. semerne (Forssell) (Acanthocephala) as Pathogenic Parasites of Farmed Minks in Finland
Authors: Nuorteva Pekka
Published: November 2009

The acanthocephalan parasites of seals, Corynosoma strumosum (Rud.) and C. semerne (Forssell) were found in one mink farm in the south western archipelago of Finland, where the minks suffered from a bloody and often fatal diarrhoeal anaemia. C. strumosum was found in the two victims of the disease examined, whereas C. semerne occurred in 75·3 per cent of the surviving minks. In a highly anaemic group of minks the mean incidence of C. semerne was 2·9 specimens per animal, whereas the incidence was 1·5 in a mildly anaemic group. The epidemiology of the disease is discussed.
On a Parasitic Nematode, Galebiella sp. Basir, 1941, from Aquatic Beetles in Egypt
Authors: Rostom Z. M. F.
Published: November 2009

The genus Galebiella Basir, 1941, has been recorded from Hydrous aculeatus Sol. (Coleoptera: Hydrophilidae) in the U.A.R. Female nematodes only were found, in the hindgut of the adult beetles.

Worms were especially abundant close to the pyloric valve and were found free in the gut lumen; a few of them were loosely attached to the gut wall.

The reaction of the hind- and midgut was almost the same yet the infection was restricted to the hindgut.

In many cases of infection the peritrophic membrane in the hindgut region became fragmented into longitudinal fibres. The intima, epithelium and muscle layers showed no changes at all.
Haemonchus longistipes Railliet & Henry, 1909 in goats in the Sudan
Authors: Hussein H. S. , Arzoun I. H. , Hussein M. F.
Published: November 2009

Haemonchus longistipes specimens were collected from experimentally infected Sudanese goats and camels for morphological studies. The specimens from goats were much smaller than those from camels, but their infectivity to camels was not affected by their passage in goats. Goats inhabiting the same areas as camels in the Sudan were found to be naturally infected with H. longistipes, but sheep were not and were resistant to experimental infection.
The effects of treatment with transfer factor, parasitic antigen and precipitated immunoglobulin on the parasitological and histopathological responses inHaemonchus contortusinfection in lambs under six months of age
Authors: MacKenzie Grace , Hunter A. R. , Ross J. G.
Published: November 2009

In lambs under six months of age infected with 10,000H. contortusthird stage larvae two effects were observed as a result of the treatment regimes administered: 1. Reduced adult worm burdens, indicating protection, occurred in the animals treated with combined transfer factor, adult parasitic antigen and precipitated immunoglobulin whereas other treatment combinations produced no significant effects. 2. Defined patterns of histological changes in the abomasa were associated with each treatment and cumulative effects were recognized when combined treatments were given. The responses induced by transfer factor treatment suggest the development of a hypersensitivity reaction outwith the changes seen in primaryH. contortuschallenge.
Prevalence of Angiostrongylus cantonensis infection in commensal rats in Bombay
Authors: Renapurkar D. M. , Bhopale M. K. , Limaye Lalita S. , Sharma K. D.
Published: November 2009

The prevalence Angiostrongylus cantonensis, a metastrongylid lungworm of rats, was investigated in three common species of rodents in the Greater Bombay area, namely, Rattus rattus, R. norvegicus and Bandicota bengalensis. In all, 737 R. norvegicus, 100 R. rattus and 100 B. bengalensis were examined and the presence of A. cantonensis infection was noticed in R. norvegicus (1·62%). About 800 slugs (Laevicaulis alte) were examined and were found to harbour third-stage larvae of Angiostrongylus.
On identifying Multiceps spp. by measurement of the large hook
Authors: Clapham Phyllis A.
Published: November 2009

The genus Multiceps has come under intense observation recently and the validity of the various species has been considered. The hook, being of a chitinous nature and therefore presumably of a less variable disposition than most other points, has been used for specific diagnosis, though as has been shown earlier, even this structure is not entirely satisfactory. But there is no other structure that is more satisfactory. When the information has been available, the blade length has been used as this is the most constant part of the hook. The small hook is of little or no diagnostic value. In many cases, however, only the range of the total length has been known.
The Degree of Heterodera Infectivity of Soil and its Determination
Authors: Fenwick D. W.
Published: November 2009

(1) A technique for measuring the infectivity of soil with Heterodera schachtii in terms of the number of larvae potentially capable of infecting plants per pound of soil is described.

(2) The liberation of the larvae is accomplished by subjecting the cysts recovered from one half-pound sample of soil to a given strength of calcium hypochlorite solution for four hours. The loss of larvae due to solution during this time was found to be negligible.

(3) It was shown that if the larvae liberated were made up to a suspension, then counts made on 0·15 cc. samples of this suspension fall into a Poisson distribution and hence the accuracy of the final determination is dependent only on the number of larvae counted.

(4) It was found that provided the soil to be examined was thoroughly mixed that it was unnecessary to examine more than one half-pound sample as there was no significant difference between the means from different samples.

(5) Figures of cyst counts tabulated alongside available larvae show the utter inadequacy of cyst counts as a measure of infectivity.

(6) No attempt is made in this paper to determine how many of the larvae are alive and viable, further research into this matter being contemplated.
Teddy Brown and the Art of Performing for the British Variety Stage
Authors: Double Oliver
Published: November 2009

British variety theatre has been largely ignored by theatre historians, in spite of its huge popularity in the early twentieth century. Here, Oliver Double examines variety through its exemplification in the work of one performer, Teddy Brown, a virtuoso xylophone player whose career coincided with the heyday of the variety stage between and just after the two world wars. The key historical and stylistic aspects of the form typified by Brown's success included the development of a stage persona, novelty, skill, participation, a distinctive musical style, and the ability to exploit the complex relationship between variety and the other types of popular entertainment of the time, notably cinema, revue, and radio. Former comedian Oliver Double is a Senior Lecturer in Drama at the University of Kent, and is the author of Stand-Up! On Being a Comedian (Methuen, 1997) and Getting the Joke: the Inner Workings of Stand-Up Comedy (Methuen, 2005). His stand-up comedy DVD Saint Pancreas is available from the University of Kent website.
Relative Tutte Polynomials for Coloured Graphs and Virtual Knot Theory
Authors: DIAO Y. , HETYEI G.
Published: November 2009

We introduce the concept of a relative Tutte polynomial of coloured graphs. We show that this relative Tutte polynomial can be computed in a way similar to the classical spanning tree expansion used by Tutte in his original paper on this subject. We then apply the relative Tutte polynomial to virtual knot theory. More specifically, we show that the Kauffman bracket polynomial (and hence the Jones polynomial) of a virtual knot can be computed from the relative Tutte polynomial of its face (Tait) graph with some suitable variable substitutions. Our method offers an alternative to the ribbon graph approach, using the face graph obtained from the virtual link diagram directly.
Prophets in the Wilderness: An Ecology of Ministerial Organization Participation in Public Affairs
Authors: Djupe Paul A. , Niles Franklyn C.
Published: November 2009

Studies of interest groups typically sample from organizations or lobbyists registered with a government – those already engaged in political action. Because of this design choice, the questions asked of organizational systems are constrained. We take a different tack, pursuing investigation of one organizational form, ministerial organizations (MOs), in a wide variety of systems to ask about whether and how they engage in public affairs across ecologies. Specifically, we ask: What pressures affect whether MOs engage a public versus private purpose? How do MOs forage in public affairs, with what size and diversity of coalition? The data result from a hyper-network survey of MO contacts, identified by a national sample of United Methodist Church clergy. We find, contrary to assertions in previous work that religious interest groups respond to ecological pressures in a similar manner as other interest groups.
Seasonality of monoterpene emission potentials in Quercus ilex and Pinus pinea: Implications for regional VOC emissions modeling
Authors: Keenan Trevor , Niinemets Ülo , Sabate Santi , Gracia Carlos , Peñuelas Josep
Published: November 2009

VOC emissions from terrestrial ecosystems provide one of the principal controls over oxidative photochemistry in the lower atmosphere and the resulting air pollution. Such atmospheric processes have strong seasonal cycles. Although similar seasonal cycles in VOC emissions from terrestrial ecosystems have been reported, regional emissions inventories generally omit the effect of seasonality on emissions. We compiled measurement data on seasonal variations in monoterpene emissions potentials for two evergreen species (Quercus ilex and Pinus pinea) and used these data to construct two contrasting seasonal response functions for the inclusion in monoterpene emission models. We included these responses in the Niinemets et al. model and compared simulation results to those of the MEGAN model, both with and without its predicted seasonality. The effect of seasonality on regional monoterpene emissions inventories for European Mediterranean forests dominated by these species was tested for both models, using the GOTILWA+ biosphere model platform. The consideration of seasonality in the Niinemets et al. model reduced total estimated annual monoterpene emissions by up to 65% in some regions, with largest reductions at lower latitudes. The MEGAN model demonstrated a much weaker seasonal response than that in the Niinemets et al. model, and did not capture the between species seasonality differences found in this study. Results suggest that previous regional model inventories based on one fixed emission factor likely overestimate regional emissions, and species‐specific expressions of seasonality may be necessary. The consideration of seasonality both largely reduces monoterpene emissions estimates, and changes their expected seasonal distribution.
Longitudinal in vivo Imaging Reveals Balanced and Branch-Specific Remodeling of Mature Cortical Pyramidal Dendritic Arbors after Stroke
Authors: Brown Craig E , Boyd Jamie D , Murphy Timothy H
Published: November 2009

The manner in which fully mature peri-infarct cortical dendritic arbors remodel after stroke, and thus may possibly contribute to stroke-induced changes in cortical receptive fields, is unknown. In this study, we used longitudinal in vivo two-photon imaging to investigate the extent to which brain ischemia can trigger dendritic remodeling of pyramidal neurons in the adult mouse somatosensory cortex, and to determine the nature by which remodeling proceeds over time and space. Before the induction of stroke, dendritic arbors were relatively stable over several weeks. However, after stroke, apical dendritic arbor remodeling increased significantly (dendritic tip growth and retraction), particularly within the first 2 weeks after stroke. Despite a threefold increase in structural remodeling, the net length of arbors did not change significantly over time because dendrite extensions away from the stroke were balanced by the shortening of tips near the infarct. Therefore, fully mature cortical pyramidal neurons retain the capacity for extensive structural plasticity and remodel in a balanced and branch-specific manner.
In vivoQuantification of Monoamine Oxidase A in Baboon Brain: A PET Study Using [11C]befloxatone and the Multi-Injection Approach
Authors: Bottlaender Michel , Valette Héric , Delforge Jacques , Saba Wadad , Guenther Ilonka , Curet Olivier , George Pascal , Dollé Frédéric , Grégoire Marie-Claude
Published: November 2009

[11C]befloxatone is a high-affinity, reversible, and selective radioligand for the in vivo visualization of the monoamine oxidase A (MAO-A) binding sites using positron emission tomography (PET). The multi-injection approach was used to study in baboons the interactions between the MAO-A binding sites and [11C]befloxatone. The model included four compartments and seven parameters. The arterial plasma concentration, corrected for metabolites, was used as input function. The experimental protocol—three injections of labeled and/or unlabeled befloxatone—allowed the evaluation of all the model parameters from a single PET experiment. In particular, the brain regional concentrations of the MAO-A binding sites ( B′max) and the apparent in vivo befloxatone affinity ( Kd) were estimated in vivo for the first time. A high binding site density was found in almost all the brain structures (170±39 and 194±26 pmol/mL in the frontal cortex and striata, respectively, n=5). The cerebellum presented the lowest binding site density (66±13 pmol/mL). Apparent affinity was found to be similar in all structures ( KdVR=6.4±1.5 nmol/L). This study is the first PET-based estimation of the Bmaxof an enzyme.
Invited Review Article: The Josephson bifurcation amplifier
Authors: Vijay R. , Devoret M. H. , Siddiqi I.
Published: November 2009

We review the theory, fabrication, and implementation of the Josephson bifurcation amplifier (JBA). At the core of the JBA is a nonlinear oscillator based on a reactively shunted Josephson junction. A weak input signal to the amplifier couples to the junction critical current I0 and results in a dispersive shift in the resonator plasma frequency ωp. This shift is enhanced by biasing the junction with a sufficiently strong microwave current Irf to access the nonlinear regime where ωp varies with Irf. For a drive frequency ωd such that Ω=2Q(1−ωd/ωp)>3, the oscillator enters the bistable regime where two nondissipative dynamical states OL and OH, which differ in amplitude and phase, can exist. The sharp I0 dependent transition from OL to OH forms the basis for a sensitive digital threshold amplifier. In the vicinity of the bistable regime (Ω<3), analog amplification of continuous signals is also possible. We present experimental data characterizing amplifier performance and discuss two specific applications—the readout of superconducting qubits (digital mode) and dispersive microwave magnetometry (analog mode).
Vibration analysis of nanoplates under uniaxial prestressed conditions via nonlocal elasticity
Authors: Murmu T. , Pradhan S. C.
Published: November 2009

In this article, nonlocal elasticity theory is applied to investigate the vibration response of nanoplates under uniaxially prestressed conditions. Nonlocal elasticity theory takes into account the small-size effects when dealing with nanostructures. Nonlocal governing equations of the prestressed nanoplate are derived and presented. Differential quadrature method is being utilized and numerical frequency solutions are obtained. Influence of small scale and uniaxial preload on the nonlocal frequency solutions is investigated. It is observed that the frequencies for nanoplates under uniaxially prestressed conditions employing classical plate theory are overestimated compared to nonlocal plate solutions. Considering the nonlocal effects, smaller critical compressive load is required to reach the buckling state of a flexural mode compared to the classical plate theory. The present research work thus reveals that the nonlocal parameter, aspect ratios, boundary conditions, and initial uniaxial prestress have significant effects on vibration response of the nanoplates.
Well-posedness of Einstein’s equation with redshift data
Authors: Winfield Christopher J.
Published: November 2009

We study the solvability of a system of ordinary differential equations derived from null geodesics of the Lemaître–Tolman–Bondi metric with data given in terms of a so-called redshift parameter. Data are introduced along these geodesics by the luminosity distance function. We check our results with luminosity distance depending on the cosmological constant and with the well-known Freedman-Robertson-Walker (FRW) model.
Scaling and correlation of vorticity fluctuations in turbulent channels
Authors: Panton Ronald L.
Published: November 2009

Data from direct numerical simulations have been correlated to examine the effects of Reynolds number on vorticity fluctuation profiles. Three different scalings are found: two in the inner region and the third in the outer region. In the inner region a two-term asymptotic expansion is required to represent the mean square vorticity profiles; ⟨ωω⟩#=⟨ωω⟩0#+⟨ωω⟩1+u∗/U0. The first scaling ⟨ωω⟩0#=⟨ωω⟩0/(u∗3U0/ν2) is for inactive motions that do not generate Reynolds shear stress. It applies to the streamwise and spanwise components. However, the zero-order term is zero for the normal vorticity component. The scrubbing of the inactive motions over the wall generates vorticity, which is a maximum at the wall, and diffuses out to about y+=50 before it decays. The fluctuating viscous wall shear stress is due entirely to this motion, and as a result the stress ratio (rms/mean) τ′/τ0=CU0/u∗ depends on the Reynolds number. The second scaling ⟨ωω⟩1+=⟨ωω⟩1/(u∗4/ν2), the same scaling as the Reynolds shear stress, is active motions. All three components participate in these motions, which are zero at the wall, rise to a peak at about y+=13–20, and fall to zero at about y+=400. This is consistent with the fact that the Reynolds shear stress is identically zero at the wall. The third scaling correlates data in the outer region using the Kolmogorov time scale ⟨ωω⟩/(u∗3/hν). Matching between the inner and outer regions has a common part (the equivalent of the log law) of ∼C/y+ or ∼C/Y for all three components. All components decrease further and become isotropic as the centerline is approached. Scaling with the Kolmogorov scale implies that dissipation is the important activity. The correlated data are fitted to simplified equations that can be formed into composite expansions to predict profiles at any Reynolds number.
Improvement of the ab initio embedded cluster method for luminescence properties of doped materials by taking into account impurity induced distortions: The example of Y2O3:Bi3+
Authors: Réal Florent , Ordejón Belén , Vallet Valérie , Flament Jean-Pierre , Schamps Joël
Published: November 2009

New ab initio embedded-cluster calculations devoted to simulating the electronic spectroscopy of Bi3+ impurities in Y2O3 sesquioxide for substitutions in either S6 or C2 cationic sites have been carried out taking special care of the quality of the environment. A considerable quantitative improvement with respect to previous studies [F. Réal et al. J. Chem. Phys. 125, 174709 (2006); F. Réal et al. J. Chem. Phys. 127, 104705 (2007)] is brought by using environments of the impurities obtained via supercell techniques that allow the whole (pseudo) crystal to relax (WCR geometries) instead of environments obtained from local relaxation of the first coordination shell only (FSR geometries) within the embedded cluster approach, as was done previously. In particular the uniform 0.4 eV discrepancy of absorption energies found previously with FSR environments disappears completely when the new WCR environments of the impurities are employed. Moreover emission energies and hence Stokes shifts are in much better agreement with experiment. These decisive improvements are mainly due to a lowering of the local point-group symmetry (S6→C3 and C2→C1) when relaxing the geometry of the emitting (lowest) triplet state. This symmetry lowering was not observed in FSR embedded cluster relaxations because the crystal field of the embedding frozen at the genuine pure crystal positions seems to be a more important driving force than the interactions within the cluster, thus constraining the overall symmetry of the system. Variations of the doping rate are found to have negligible influence on the spectra. In conclusion, the use of WCR environments may be crucial to render the structural distortions occurring in a doped crystal and it may help to significantly improve the embedded-cluster methodology to reach the quantitative accuracy necessary to interpret and predict luminescence properties of doped materials of this type.
Dielectric properties of single crystalline PrO2(111)/Si(111) heterostructures: Amorphous interface and electrical instabilities
Authors: Seifarth O. , Walczyk Ch. , Lupina G. , Dabrowski J. , Zaumseil P. , Weidner G. , Müssig H.-J. , Schroeder T.
Published: November 2009

Single crystalline PrO2(111)/Si(111) heterostructures are flexible buffers for global Ge integration on Si. A combined materials science–electrical characterization is carried out to study the influence of postdeposition annealing in 1 bar oxygen at 300–600 °C on the dielectric properties of PrO2(111)/Si(111). The materials science transmission electron microscopy and x-ray reflectometry studies reveal that postdeposition oxidation of the PrO2(111)/Si(111) boundary results in an amorphous interface (IF) layer, which grows in thickness with temperature. Nondestructive depth profiling synchrotron radiation-based x-ray photoelectron spectroscopy and x-ray absorption spectroscopy methods demonstrate that this amorphous IF layer is composed of two Pr-silicate phases, namely, with increasing distance from Si, a SiO2-rich and a SiO2-poor Pr silicate. The electronic band offset diagram shows that the wide band gap dielectric Pr silicate results in higher band offsets with respect to Si than the medium band gap dielectric PrO2. The electrical characterization studies by C-V measurements show that (a) well-behaved dielectric properties of the PrO2(111)/IF/Si(111) are achieved in a narrow postdeposition oxidation window of 400–450 °C and that (b) defects are distributed over the Pr-silicate IF layer. Temperature-dependent J-V studies report furthermore that the formation of the single crystalline PrO2/amorphous Pr-silicate bilayer structure on Si(111) results in (a) improved insulating properties and (b) strong electrical instability phenomena in the form of a Maxwell–Wagner instability and dielectric relaxation.
Electron accumulation at nonpolar and semipolar surfaces of wurtzite InN from generalized infrared ellipsometry
Authors: Darakchieva V. , Schubert M. , Hofmann T. , Monemar B. , Hsiao Ching-Lien , Liu Ting-Wei , Chen Li-Chyong , Schaff W. J. , Takagi Y. , Nanishi Y.
Published: November 2009

The free electron properties of nonpolar (112¯0)-oriented and semipolar (101¯1)-oriented wurtzite InN films are studied by generalized infrared ellipsometry (GIRSE). We demonstrate the sensitivity of GIRSE to the surface charge accumulation layer and find a distinct surface electron accumulation to occur at all surfaces. The obtained surface electron sheet densities are found to vary from 0.9×1013 to 2.3×1014 cm−2 depending on the surface orientation and bulk electron concentration. The upper limits of the surface electron mobility parameters of 417–644 cm2/V s are determined and discussed in the light of electron confinement at the surface.
Alpha particle detection with GaN Schottky diodes
Authors: Polyakov A. Y. , Smirnov N. B. , Govorkov A. V. , Markov A. V. , Kozhukhova E. A. , Gazizov I. M. , Kolin N. G. , Merkurisov D. I. , Boiko V. M. , Korulin A. V. , Zalyetin V. M. , Pearton S. J. , Lee I.-H. , Dabiran A. M. , Chow P. P.
Published: November 2009

Ni/GaN Schottky diode radiation detectors were fabricated on 3-μm-thick unintentionally doped n-GaN films grown by molecular beam epitaxy (MBE) and metal organic chemical vapor deposition (MOCVD) and on 12-μm-thick undoped n-GaN layers prepared by epitaxial lateral overgrowth (ELOG). The reverse current of all detector structures was <10−9 A for bias voltages necessary for detector operation, with the level of background donor doping of <1015 cm−3. With this doping level the space charge region of the Schottky diode could be extended to the entire thickness of the films. The charge collection efficiency of the detectors was close to 100% for MOCVD and ELOG detectors for α-particles with range comparable to the thickness of the layer. Electrical properties and deep trap spectra were also studied. The collection efficiency decreased when the concentra-tion of deep electron traps, particularly Ec-0.6 eV traps, increased in MBE grown films.
Experimental investigation on enhanced mass transfer in nanofluids
Authors: Fang Xiaopeng , Xuan Yimin , Li Qiang
Published: November 2009

Experiment on mass diffusion of fluorescent Rhodamine B in Cu-water nanofluids is carried out to investigate enhancement effect of mass transfer in binary nanofluid. An optical experimental system is designed to measure the diffusion coefficient of Rhodamine B in the nanofluid with different nanoparticle volume fractions under different temperatures. The effects of nanoparticles and fluid temperature on mass diffusion inside the nanofluid are discussed from the experimental data. The experimental results show that the diffusion coefficient of fluorescent Rhodamine B in nanofluids is bigger than that in de-ionized water.
Transfer of graphene layers grown on SiC wafers to other substrates and their integration into field effect transistors
Authors: Unarunotai Sakulsuk , Murata Yuya , Chialvo Cesar E. , Kim Hoon-sik , MacLaren Scott , Mason Nadya , Petrov Ivan , Rogers John A.
Published: November 2009

This letter presents a simple method for transferring epitaxial sheets of graphene on silicon carbide to other substrates. The graphene was grown on the (0001) face of 6H-SiC by thermal annealing at 1550 °C in a hydrogen atmosphere. Transfer was accomplished using a peeling process with a bilayer film of gold/polyimide, to yield graphene with square millimeters of coverage on the target substrate. Raman spectroscopy provided evidence that the transferred material is single layer. Back gated field-effect transistors fabricated on oxidized silicon substrates with Cr/Au as source-drain electrodes exhibited ambipolar characteristics with hole mobilities of ∼100 cm2/V-s, and negligible influence of resistance at the contacts.
Nanomechanical mass detection using nonlinear oscillations
Authors: Dai Mai Duc , Eom Kilho , Kim Chang-Wan
Published: November 2009

Nanomechanical resonators have allowed the in vitro molecular recognition. Most of detection is implemented in harmonic oscillation regime, albeit nanomechanical resonators can easily reach the nonlinear oscillation regime. In this letter, we have studied the nanomechanical mass detection using nonlinear oscillators based on continuum elastic model. It is shown that nonlinear oscillation leads to the unique resonant frequency shift due to mass adsorption, quite different from that in harmonic oscillation. Moreover, the effect of mechanical tension on the mass detection in nonlinear oscillation is also discussed. This study highlights the nonlinear oscillation for label-free detection.
Three-dimensional nanoparticle tracking and simultaneously membrane profiling during endocytosis of living cells
Authors: Wang Chun-Chieh , Liang Chia-Pin , Lee Chau-Hwang
Published: November 2009

By utilizing a wide-field optical profiling technique and a bright-field particle-tracking algorithm, we record the tracks of gold nanoparticles as well as the topography of cell membranes during the endocytosis processes. The motion of 60 nm gold particles relative to the membrane is directly visualized without fluorescence labeling. The positioning accuracy of gold nanoparticles in three dimensions is nearly 20 nm. On the basis of the simultaneous particle tracks and membrane topography, we estimate the internalization efficiency of transferrin-coated gold nanoparticles on fibroblasts.
Distinct ubiquitin ligases act sequentially for RNA polymerase II polyubiquitylation
Authors: Harreman Michelle , Taschner Michael , Sigurdsson Stefan , Anindya Roy , Reid James , Somesh Baggavalli , Kong Stephanie E. , Banks Charles A. S. , Conaway Ronald C. , Conaway Joan W. , Svejstrup Jesper Q.
Published: November 2009

The proteasome degrades proteins modified by polyubiquitylation, so correctly controlled ubiquitylation is crucial to avoid unscheduled proteolysis of essential proteins. The mechanism regulating proteolysis of RNAPII has been controversial since two distinct ubiquitin ligases (E3s), Rsp5 (and its human homologue NEDD4) and Elongin-Cullin complex, have both been shown to be required for its DNA-damage-induced polyubiquitylation. Here we show that these E3s work sequentially in a two-step mechanism. First, Rsp5 adds mono-ubiquitin, or sometimes a ubiquitin chain linked via ubiquitin lysine 63 that does not trigger proteolysis. When produced, the K63 chain can be trimmed to mono-ubiquitylation by an Rsp5-associated ubiquitin protease, Ubp2. Based on this mono-ubiquitin moiety on RNAPII, an Elc1/Cul3 complex then produces a ubiquitin chain linked via lysine 48, which can trigger proteolysis. Likewise, for correct polyubiquitylation of human RNAPII, NEDD4 cooperates with the ElonginA/B/C-Cullin 5 complex. These data indicate that RNAPII polyubiquitylation requires cooperation between distinct, sequentially acting ubiquitin ligases, and raise the intriguing possibility that other members of the large and functionally diverse family of NEDD4-like ubiquitin ligases also require the assistance of a second E3 when targeting proteins for degradation.
The response of heterotrophic activity and carbon cycling to nitrogen additions and warming in two tropical soils
Authors: CUSACK DANIELA F. , TORN MARGARET S. , McDOWELL WILLIAM H. , SILVER WHENDEE L.
Published: November 2009

Nitrogen (N) deposition is projected to increase significantly in tropical regions in the coming decades, where changes in climate are also expected. Additional N and warming each have the potential to alter soil carbon (C) storage via changes in microbial activity and decomposition, but little is known about the combined effects of these global change factors in tropical ecosystems. In this study, we used controlled laboratory incubations of soils from a long‐term N fertilization experiment to explore the sensitivity of soil C to increased N in two N‐rich tropical forests. We found that fertilization corresponded to significant increases in bulk soil C concentrations, and decreases in C loss via heterotrophic respiration (P< 0.05). The increase in soil C was not uniform among C pools, however. The active soil C pool decomposed faster with fertilization, while slowly cycling C pools had longer turnover times. These changes in soil C cycling with N additions corresponded to the responses of two groups of microbial extracellular enzymes. Smaller active C pools corresponded to increased hydrolytic enzyme activities; longer turnover times of the slowly cycling C pool corresponded to reduced activity of oxidative enzymes, which degrade more complex C compounds, in fertilized soils. Warming increased soil respiration overall, and N fertilization significantly increased the temperature sensitivity of slowly cycling C pools in both forests. In the lower elevation forest, respired CO2 from fertilized cores had significantly higher Δ14C values than control soils, indicating losses of relatively older soil C. These results indicate that soil C storage is sensitive to both N deposition and warming in N‐rich tropical soils, with interacting effects of these two global change factors. N deposition has the potential to increase total soil C stocks in tropical forests, but the long‐term stability of this added C will likely depend on future changes in temperature.
The optimal mode of delivery for the haemophilia carrier expecting an affected infant is vaginal delivery
Authors: LJUNG R.
Published: November 2009

Summary.  The optimal mode of delivery of a haemophilia carrier expecting a child is still a matter of uncertainty and debate. The aim of this commentary/review is to suggest that normal vaginal delivery should be the recommended mode of delivery for the majority of carriers, based on review of studies on obstetric aspects of haemophilia. About 2.0–4.0% of all haemophilia boys born in countries with a good standard of health care will suffer from ICH during the neonatal period. This is an average figure including all modes of delivery and regardless of whether the carrier status of the mother or the haemophilia status of the foetus was known or not at the time of delivery. On the basis of current literature, one may conclude that the risk of serious bleeding in the neonate affected with haemophilia is small in conjunction with normal vaginal delivery. It should be possible to further reduce the low frequency of complications if appropriate precautions are taken when planning the delivery in pregnant woman with known carrier status, if the sex of the foetus is known and, even more, when the haemophilia status of the foetus is known. Instrumental delivery such as use of vacuum extraction and foetal scalp monitors must be avoided at delivery of carriers.
Nurses' satisfaction with shiftwork and associations with work, home and health characteristics: a survey in the Netherlands
Authors: Peters Velibor P.J.M. , De Rijk Angelique E. , Boumans Nicolle P.G.
Published: November 2009

Title.  Nurses' satisfaction with shiftwork and associations with work, home and health characteristics: a survey in the Netherlands.

Aim.  This paper is a report of a study conducted to determine if satisfaction with irregular working hours that are a form of shiftwork operates as a mediator between work and home characteristics and health problems.

Background.  Shiftwork contributes to health problems, decreased well‐being and poorer health habits. It also affects employees’ decisions to leave the healthcare sector. Although many nurses voluntarily work shifts, there have been few studies of their satisfaction with irregular working hours when these are a form of shiftwork.

Methods.  A survey was carried out with 144 nurses working in three nursing homes and one care home in the Netherlands. Questionnaires were distributed in 2003 to 233 nurses who worked shifts (response rate 60%). The questionnaire contained items on work and home characteristics, satisfaction with irregular working hours that are a form of shiftwork and health. A new scale to measure satisfaction with irregular working hours was constructed.

Results.  All work characteristics, but no home characteristics, were associated with satisfaction with irregular working hours. The work characteristics ‘job demands’ and the home characteristics ‘autonomy at home’ and ‘home demands’ were associated with health. Satisfaction with irregular working hours did not mediate between work/home characteristics and health. Those reporting more social support, lower job demands and more job autonomy were more satisfied with their irregular working times that were a form of shiftwork.

Conclusions.  Satisfaction with irregular working hours is a useful construct that requires further longitudinal study. The results also underline the importance of considering home characteristics when predicting health outcomes.
Nurses’ attitudes towards perinatal bereavement care
Authors: Moon Fai Chan , Gordon Arthur David
Published: November 2009

Title.  Nurses’ attitudes towards perinatal bereavement care.

Aim.  This paper is a report of a study conducted to explore the factors associated with nurses and midwives’ attitudes towards perinatal bereavement care.

Background.  Caring for and supporting parents whose infant has died is extremely demanding, difficult and stressful. In some situations nurses may experience personal failure, feel helpless, and need to distance themselves from bereaved parents because they feel unable to deal with the enormity of the parental feelings of loss.

Method.  A correlational questionnaire study using convenience sampling was carried out in Singapore in 2007 with 185 nurses/midwives in one obstetrics and gynaecology unit.

Results.  Regression models showed that nurses/midwives with religious beliefs and those with more positive attitudes to the importance of hospital policy and training for bereavement care were statistically significantly more likely to have a positive attitude towards perinatal bereavement care. Nurses emphasized their need for increased knowledge and training on how to cope with bereaved parents and requested greater support from team members and the hospital.

Conclusion.  Bereavement counselling education and preceptorship supervision are recommended to reduce this stressful experience, increase the confidence and expertise of novices, and lead to increased quality of care for bereaved parents.
Dundee Ready Education Environment Measure: psychometric testing with Chinese nursing students
Authors: Wang Jian , Zang Shuang , Shan Tianming
Published: November 2009

Title.  Dundee Ready Education Environment Measure: psychometric testing with Chinese nursing students.

Aim.  This paper is a report of the psychometric testing of the Dundee Ready Education Environment Measure with Chinese nursing students.

Background.  Although the Dundee Ready Education Environment Measure has been widely used to measure educational environments in the healthcare professions, no psychometric evaluation of the measure with Chinese nursing students has been reported.

Method.  Data from 214 nursing students were collected during a 2‐month period between December, 2004 and January, 2005. Exploratory factor analysis, internal consistency reliability and Cronbach’s alpha were examined.

Results.  Five factors were found by principal components analysis with Oblimin with Kaiser Normalization rotation. The original factor names were maintained, but items in each factor changed. These five factors all achieved eigenvalues >1, and in total accounted for 52·186% of the variance. Cronbach’s alpha ranged from 0·623 to 0·9 across factors, with an overall alpha of 0·949.

Conclusion.  The Chinese version of the Dundee Ready Education Environment Measure could be a valuable measurement for nursing educators in professional development programmes and nursing curriculum design. Further studies need in different Chinese nursing schools and larger sample sizes to be conducted to validate its stability and factor structure.
Response of the prairie–forest border to climate change: impacts of increasing drought may be mitigated by increasing CO2
Authors: Wyckoff Peter H. , Bowers Rachel
Published: November 2009

1.
Quercus macrocarpa (bur oak) is the dominant tree species along much of the prairie–forest border in the northern‐central United States, and movement of Q. macrocarpa in response to climate change may determine the rate at which the prairie–forest ecotone shifts. To investigate likely controls over Q. macrocarpa performance at the edge of its range, we used tree rings to establish the links between drought, growth‐rate and mortality for three sites spanning the prairie–forest border in Minnesota.

2.
Quercus macrocarpa growth during the 20th century correlates strongly with the Palmer Drought Severity Index (PDSI) and more weakly with raw temperature and precipitation values for all three sites. However, the sensitivity of annual growth rates to drought has steadily declined over time as evidenced by increasing growth residuals and higher growth rates for a given PDSI value after 1950 compared with the first half of the century. We hypothesize that increased atmospheric carbon dioxide concentration may lead to increased water‐use efficiency, although we cannot rule out other environmental factors.

3. Because growth is an excellent predictor of Q. macrocarpa mortality, growth–climate relationships provide information on whether oak forests will contract, because of individual tree death, when climate changes. For Q. macrocarpa, declining sensitivity of growth to drought translates into lower predicted mortality rates at all sites. At one site, declining moisture sensitivity yields a 49% lower predicted mortality from a severe drought (PDSI = −8, on par with the worst 1930s ‘American Dust Bowl’ droughts in our study region).

4. Unless the changing relationship between growth and climate is incorporated into forest simulation models, the predicted rate of established tree dieback in a warmer, drier climate may be exaggerated.

5.
Synthesis. Adult Quercus macrocarpa trees appear to be increasingly insensitive to drought‐induced mortality. Because the species is dominant at the prairie–forest ecotone in the northern‐central United States, movement of the ecotone in response to climate change may be delayed for decades.
Detection and identification of Bartonella sp. in fleas from carnivorous mammals in Andalusia, Spain
Authors: MÁRQUEZ F. J. , MILLÁN J. , RODRÍGUEZ‐LIÉBANA J. J. , GARCÍA‐EGEA I. , MUNIAIN M. A.
Published: November 2009

A total of 559 fleas representing four species (Pulex irritans, Ctenocephalides felis, Ctenocephalides canis and Spilopsyllus cuniculi) collected on carnivores (five Iberian lynx Lynx pardinus, six European wildcat Felis silvestris, 10 common genet Genetta genetta, three Eurasian badger Meles meles, 22 red fox Vulpes vulpes, 87 dogs and 23 cats) in Andalusia, southern Spain, were distributed in 156 pools of monospecific flea from each carnivore, and tested for Bartonella infection in an assay based on polymerase chain reaction (PCR) amplification of the 16 S–23 S rRNA intergenic spacer region. Twenty‐one samples (13.5%) were positive and the sequence data showed the presence of four different Bartonella species. Bartonella henselae was detected in nine pools of Ctenocephalides felis from cats and dogs and in three pools of Ctenocephalides canis from cats; Bartonella clarridgeiae in Ctenocephalides felis from a cat, and Bartonella alsatica in Spilopsyllus cuniculi from a wildcat. DNA of Bartonella sp., closely related to Bartonella rochalimae, was found in seven pools of Pulex irritans from foxes. This is the first detection of B. alsatica and Bartonella sp. in the Iberian Peninsula. All of these Bartonella species have been implicated as agents of human diseases. The present survey confirms that carnivores are major reservoirs for Bartonella spp.