bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of viscosity of base fluid on thermal conductivity of nanofluids
Authors: Tsai Tsung-Han , Kuo Long-Sheng , Chen Ping-Hei , Yang Chin-Ting
Published: December 2008

This study aims to investigate the effect of viscosity of the base fluid on the thermal conductivity of nanofluids in which Fe3O4 nanoparticles are suspended in the base fluid composed of diesel oil and polydimethylsiloxane. Viscosity of the base fluid is varied by changing the volumetric fractions between both fluids. The measured thermal conductivity of nanofluids gradually approaches the value predicted by the Maxwell equation by increasing the viscosity. It demonstrates that the viscosity of nanofluids does affect the thermal conductivity of nanofluids, and the Brownian motion of suspended particles could be an important factor that enhances the thermal conductivity of nanofluids.
Enhanced field emission from ZnO nanotetrapods on a carbon nanofiber buffered Ag film by screen printing
Authors: Li Chi , Hou Kai , Yang Xiaxi , Qu Ke , Lei Wei , Zhang Xiaobing , Wang Baoping , Sun X. W.
Published: December 2008

Field emission properties of screen-printed ZnO nanotetrapods on a carbon nanofiber buffered Ag electrode were studied. The turn-on electric field (at a current of 0.1 μA/cm2) and maximum emission current are 0.6 V/μm and 2.8 mA/cm2 (at a field of 2.2 V/μm), which were significantly improved compared to the control device made of ZnO nanotetrapods on Ag directly without a carbon nanofiber buffer. The improved field emission is due to the better contact (both mechanical and electrical) formed with a carbon nanofiber buffer.
Ultrafast carrier capturing in GaInP/Er,O-codoped GaAs/GaInP laser diodes grown by organometallic vapor phase epitaxy
Authors: Terai Y. , Hidaka K. , Fujii K. , Takemoto S. , Tonouchi M. , Fujiwara Y.
Published: December 2008

Carrier capturing in GaInP/Er,O-codoped GaAs (GaAs:Er,O)/GaInP laser diodes (LDs) was investigated by means of the threshold current density (Jth) of laser emission. The Er-doped LDs showed laser emission of the GaAs band edge at room temperature, and its Jth increases with the Er flow rate during the growth. In the dependence of Jth on reciprocal cavity length, the effective gain factor of the LDs decreased by the codoping of Er and O. These results reveal that ultrafast capturing of injected carriers at an Er-related trap level is accomplished even in the stimulated emission region of GaAs. The fast capturing process allowed us to observe both the spontaneous intra-4f-shell emission due to Er3+ ions at 1.54 μm and the stimulated emission at the GaAs band edge (∼840 nm) in the Er-doped LDs.
Reduced hole mobility due to the presence of excited states in poly-(3-hexylthiophene)
Authors: Song J. Y. , Stingelin N. , Gillin W. P. , Kreouzis T.
Published: December 2008

The hole mobility in poly-(3-hexylthiophene) samples is measured by the dark injection transient technique in both hole only and ambipolar devices. By applying a small offset bias prior to the voltage step, electronic excited states are generated in the ambipolar but not in the hole only devices. The presence of excited states reduces the room temperature hole mobility (typically 5×10−5 cm2 V−1 s−1) by as much as 15% compared to that measured without offset, in contrast to the hole only devices where no significant mobility reduction is seen at the same, or indeed higher, current densities. We attribute the lower mobility to interactions between the charge carriers and the long lived triplet states and to an effective reduction in the number of transport sites available.
Power scaling of coherent terahertz pulses by stacking GaAs wafers
Authors: Jiang Yi , Ding Yujie J. , Zotova Ioulia B.
Published: December 2008

We demonstrate that the average output power of the terahertz pulses generated by difference-frequency generation in stacked GaAs wafers is scaled up by a factor of 160. Such power scaling is made possible by achieving first-order quasiphase matching for the efficient terahertz conversion in stacked 590 μm thick (110) GaAs wafers using two CO2 laser pulses. The highest average output power is measured to be 29.8 μW by stacking ten wafers.
Nonvolatile memory devices with high density ruthenium nanocrystals
Authors: Mao Ping , Zhang Zhigang , Pan Liyang , Xu Jun , Chen Peiyi
Published: December 2008

The nonvolatile memory transistor devices with embedded ruthenium (Ru) nanocrystals (NCs) are fabricated in a compatible way with conventional complementary metal-oxide semiconductor technology. The rapid thermal annealing for the whole gate stacks is used to form Ru NCs in pre-existed SiO2 matrix. Monocrystal Ru NCs with high density (3×1012 cm−2), small size (2–3 nm), and good uniformity both in spatial distribution and morphology are elaborated. A substantial memory window of 3.5 V is obtained and explained by the charging and effects of Ru NCs. The mechanisms of work function engineering are also discussed in this paper.
Carbon nanocone: A promising thermal rectifier
Authors: Yang Nuo , Zhang Gang , Li Baowen
Published: December 2008

With molecular dynamics simulations, we demonstrate very obvious thermal rectification in large temperature range from 200 to 400 K in nanocone. We also observe that the rectification of nanocone does not depend on the length very sensitively, which is in stark contrast with the nanotube thermal rectifier in which the rectification decreases dramatically as the length increases. Our work demonstrates that carbon nanocone is a promising practical phononic device.
Modification of the electrical characteristics of single wall carbon nanotubes through selective functionalization
Authors: Ni C. , Chattopadhyay J. , Billups W. E. , Bandaru P. R.
Published: December 2008

We propose a scheme of carrier doping single-walled nanotubes, which involves the selective addition of organic functional groups. It is shown that electron transfer from/to the attached group can be used to diminish/enhance the intrinsic, ambient, p-type conduction. Dodecyl functional group attachment, in addition to compensating the positive hole carriers, has been shown to reduce hysteretic behavior in electrical transport.
Space, behavior, and environmental perception in open-plan offices: A prospective study
Authors: Rashid Mahbub , Wineman Jean , Zimring Craig
Published: December 2008

Abstract. This prospective research study was conducted at a government office which moved from an open-plan office with somewhat enclosed workspaces to another open-plan office with open workspaces. The study at the old office was conducted almost one year before the move, and the study at the new office was conducted more than one year after the move. The purpose of this study was threefold: (1) to measure and evaluate changes in patterns of accessibility and visibility due to changes in office layout, (2) to understand the effects of layout changes on observed behaviors, and (3) to determine the effects of layout changes on environmental perception. The study included the analysis of visibility and accessibility of each layout using space syntax techniques, field observations of behaviors, and questionnaire surveys of employees’ perceptions of privacy, job satisfaction, and commitment to the organization. During field observations, movement, visible copresence (ie the number of people visible from a space), and face-to-face interaction were observed along a predefined route in each office. Thirty-five people responded to the questionnaire survey at the old office. Out of the thirty five, only twenty nine were available for survey at the new office. On the basis of the questionnaire survey data, three multi-item scales were constructed in order to measure perceived privacy, job satisfaction, and commitment to organization. Results indicate better visibility and accessibility, increased face-to-face interaction, and improved perceived privacy at the new office. Results also show consistent effects of space on movement, and significant positive correlations between perceived privacy, job satisfaction, and commitment to the organization at these locations, despite significant design differences. Implications of the research results and limitations of the research design are discussed.
Land-Use-Change Modeling Using Unbalanced Support-Vector Machines
Authors: Huang Bo , Xie Chenglin , Tay Richard , Wu Bo
Published: December 2008

Modeling land-use change is a prerequisite to understanding the complexity of land-use-change patterns. This paper presents a novel method to model urban land-use change using support-vector machines (SVMs), a new generation of machine learning algorithms used in classification and regression domains. An SVM modeling framework has been developed to analyze land-use change in relation to various factors such as population, distance to roads and facilities, and surrounding land use. As land-use data are generally unbalanced, in the sense that the unchanged data overwhelm the changed data, traditional methods are incapable of classifying relatively minor land-use changes with high accuracy. To circumvent this problem, an unbalanced SVM has been adopted by enhancing the standard SVMs. A case study of Calgary land-use change demonstrates that the unbalanced SVMs can achieve high and reliable performance for land-use-change modeling.
Evaluating Project Deadweight Measures: Evidence from Finnish Business Subsidies
Authors: Tokila Anu , Haapanen Mika
Published: December 2008

An important problem in measuring the impacts of business subsidies is their separation from deadweight, which refers to changes that would have occurred even in the absence of intervention. Both public and private assessments have been used previously to study deadweigh, but so far little is known about how they correspond to each other. To address this issue we conducted a joint evaluation of the private and public assessments of deadweight for Finnish business projects. A unique dataset combines large register data with both public and private information on projects financed in 2000–03. First, our results suggest that the different measures for deadweight are greatly uncorrelated, and thus cannot be used as substitutes. Second, characteristics affecting the public and private measures of deadweight are identified using ordered probit models. We find that the public and private sectors emphasize different factors in their assessment of deadweight. Third, an upper bound for the level of deadweight spending is estimated at 73.8%.
Response of bahiagrass carbon assimilation and photosystem activity to below optimum temperatures
Authors: Kakani Vijaya G. , Boote Kenneth J. , Reddy K. Raja , Lang David J.
Published: December 2008

Photosynthesis and growth of tropical grasses are sensitive to cool season temperatures but information on the responsive mechanisms is limited in many species including bahiagrass (Paspalum notatum Flueggé). Therefore, an experiment was conducted in sunlit, controlled environment chambers to determine the effect of below optimum temperatures on leaf net photosynthesis (A) and chlorophyll fluorescence (F) and response to internal [CO2] (Ci) and photosynthetic photon flux density (PPFD) of A and F of bahiagrass. Five day/night temperatures of 14/6, 18/10, 22/14, 26/18 and 30/22°C were imposed from 55 to 100 days after transplanting for plants grown initially for 55 days at 30/22°C. Leaf A and F were measured from 1000 to 1400 hours between –1 to 35 days after imposing temperature treatments. Leaf A–F/Ci and A–F/PPFD response curves were measured between 11 and 20 days after start of temperature treatments. After 35 days of treatment, the cold acclimation response of leaf A was assessed by lowering temperature in all treatments to 6°C and measuring A and F for a 3-day period. Repeated-measures analysis showed significant effects of time, temperature and time × temperature. The reduction of A on the first day of cold shock was 64, 37, 61, 64 and 81% in plants previously grown at 14, 18, 22, 26 and 30°C, respectively, which indicates acclimation at 18°C. Below optimum temperature significantly lowered CO2-saturated net photosynthesis (Asat), carboxylation efficiency (CE) and electron transport rate (ETR) derived from A–F/Ci curves. Below optimum temperature also lowered light-saturated photosynthesis (Amax), Rd and ETR derived from A–F/PPFD curves. The relationship between φCO2 and φPSII showed that bahiagrass A was more sensitive than electron transport at below optimum temperatures, which may be associated with increased CO2 leakage and over-cycling of C4 acid cycle. The leaf-level photosynthesis parameters and their response functions will also help to improve algorithms for simulating forage growth under variable temperature conditions.
The promoter from SlREO, a highly-expressed, root-specific Solanum lycopersicum gene, directs expression to cortex of mature roots
Authors: Jones Matthew O. , Manning Kenneth , Andrews John , Wright Carole , Taylor Ian B. , Thompson Andrew J.
Published: December 2008

Root-specific promoters are valuable tools for targeting transgene expression, but many of those already described have limitations to their general applicability. We present the expression characteristics of SlREO, a novel gene isolated from tomato (Solanum lycopersicum L.). This gene was highly expressed in roots but had a very low level of expression in aerial plant organs. A 2.4-kb region representing the SlREO promoter sequence was cloned upstream of the uidA GUS reporter gene and shown to direct expression in the root cortex. In mature, glasshouse-grown plants this strict root specificity was maintained. Furthermore, promoter activity was unaffected by dehydration or wounding stress but was somewhat suppressed by exposure to NaCl, salicylic acid and jasmonic acid. The predicted protein sequence of SlREO contains a domain found in enzymes of the 2-oxoglutarate and Fe(II)-dependent dioxygenase superfamily. The novel SlREO promoter has properties ideal for applications requiring strong and specific gene expression in the bulk of tomato root tissue growing in soil, and is also likely to be useful in other Solanaceous crops.
Optimising methods for monitoring programs: Olympic marmots as a case study
Authors: Witczuk Julia , Pagacz Stanislaw , Mills L. Scott
Published: December 2008

Monitoring of rare and declining species is one of the most important tasks of wildlife managers. Here we present a large-scale, long-term monitoring program for Olympic marmot (Marmota olympus) throughout its range across a logistically challenging mountainous park. Our multiple-stage process of survey design accounts for the difficulty imposed by access to remote habitats and funding constraints. The Olympic marmot is endemic to the Olympic Mountains, Washington State, USA. Although nearly all of its range is enclosed within Olympic National Park, declines and local extirpations of the species have been documented. We considered several possible alternative survey approaches, and propose a monitoring program designed to reflect extinction–recolonisation dynamics using presence–absence data. The sampling design is based on annual surveys of a set of at least 25 randomly selected clusters (closely located groups of sites with record of current or historical occupancy by marmots), and supplemented by sampling 15 never-occupied sites to test for new colonisations. The monitoring plan provides a framework that park managers can use for assessing changes over time in Olympic marmot distribution across the range of the species. Our sampling design may serve as a useful case study for establishing monitoring programs for other species with clumped distributions.
Protective T cell immunity against respiratory syncytial virus is efficiently induced by recombinant BCG
Authors: Bueno Susan M. , González Pablo A. , Cautivo Kelly M. , Mora Jorge E. , Leiva Eduardo D. , Tobar Hugo E. , Fennelly Glenn J. , Eugenin Eliseo A. , Jacobs William R. , Riedel Claudia A. , Kalergis Alexis M.
Published: December 2008

Respiratory syncytial virus (RSV) is one of the leading causes of childhood hospitalization and a major health burden worldwide. Unfortunately, because of an inefficient immunological memory, RSV infection provides limited immune protection against reinfection. Furthermore, RSV can induce an inadequate Th2-type immune response that causes severe respiratory tract inflammation and obstruction. It is thought that effective RSV clearance requires the induction of balanced Th1-type immunity, involving the activation of IFN-γ-secreting cytotoxic T cells. A recognized inducer of Th1 immunity isMycobacterium bovisbacillus Calmette–Guérin (BCG), which has been used in newborns for decades in several countries as a tuberculosis vaccine. Here, we show that immunization with recombinant BCG strains expressing RSV antigens promotes protective Th1-type immunity against RSV in mice. Activation of RSV-specific T cells producing IFN-γ and IL-2 was efficiently obtained after immunization with recombinant BCG. This type of T cell immunity was protective against RSV challenge and caused a significant reduction of inflammatory cell infiltration in the airways. Furthermore, mice immunized with recombinant BCG showed no weight loss and reduced lung viral loads. These data strongly support recombinant BCG as an efficient vaccine against RSV because of its capacity to promote protective Th1 immunity.
The angiogenic response is dictated by β3 integrin on bone marrow–derived cells
Authors: Feng Weiyi , McCabe N. Patrick , Mahabeleshwar Ganapati H. , Somanath Payaningal R. , Phillips David R. , Byzova Tatiana V.
Published: December 2008

Angiogenesis is dependent on the coordinated action of numerous cell types. A key adhesion molecule expressed by these cells is the αvβ3 integrin. Here, we show that although this receptor is present on most vascular and blood cells, the key regulatory function in tumor and wound angiogenesis is performed by β3 integrin on bone marrow–derived cells (BMDCs) recruited to sites of neovascularization. Using knockin mice expressing functionally stunted β3 integrin, we show that bone marrow transplantation rescues impaired angiogenesis in these mice by normalizing BMDC recruitment. We demonstrate that αvβ3 integrin enhances BMDC recruitment and retention at angiogenic sites by mediating cellular adhesion and transmigration of BMDCs through the endothelial monolayer but not their release from the bone niche. Thus, β3 integrin has the potential to control processes such as tumor growth and wound healing by regulating BMDC recruitment to sites undergoing pathological and adaptive angiogenesis.
α–E-catenin binds to dynamitin and regulates dynactin-mediated intracellular traffic
Authors: Lien Wen-Hui , Gelfand Vladimir I. , Vasioukhin Valeri
Published: December 2008

α–Epithelial catenin (E-catenin) is an important cell–cell adhesion protein. In this study, we show that α–E-catenin also regulates intracellular traffic by binding to the dynactin complex component dynamitin. Dynactin-mediated organelle trafficking is increased in α–E-catenin−/− keratinocytes, an effect that is reversed by expression of exogenous α–E-catenin. Disruption of adherens junctions in low-calcium media does not affect dynactin-mediated traffic, indicating that α–E-catenin regulates traffic independently from its function in cell–cell adhesion. Although neither the integrity of dynactin–dynein complexes nor their association with vesicles is affected by α–E-catenin, α–E-catenin is necessary for the attenuation of microtubule-dependent trafficking by the actin cytoskeleton. Because the actin-binding domain of α–E-catenin is necessary for this regulation, we hypothesize that α–E-catenin functions as a dynamic link between the dynactin complex and actin and, thus, integrates the microtubule and actin cytoskeleton during intracellular trafficking.
Modifications of residual viraemia in human immunodeficiency virus-1-infected subjects undergoing repeated highly active antiretroviral therapy interruptions
Authors: Palmisano Lucia , Giuliano Marina , Bucciardini Raffaella , Andreotti Mauro , Fragola Vincenzo , Pirillo Maria F. , Weimer Liliana E. , Mancini Maria G. , Vella Stefano
Published: December 2008

Residual viraemia is detectable in the majority of human immunodeficiency virus (HIV)-infected subjects with plasma HIV-1 RNA <50 copies ml−1. In the present study, the impact of repeated treatment interruptions on residual HIV-1 viraemia was investigated in 58 subjects enrolled in the ISS-PART, a multicentre, randomized clinical trial comparing 24 months of continuous (arm A) and intermittent (arm B) highly active antiretroviral therapy (HAART). Residual viraemia was measured by a modified Roche Amplicor HIV-1 RNA assay (limit of detection 2.5 copies ml−1). At baseline, the median value of residual viraemia was 2.5 copies ml−1in both arms; after 24 months, the median value was 2.5 in arm A and 8.3 in arm B. The median change from baseline to month 24 was significantly different between patients under continuous or intermittent HAART: 0 copies ml−1(range −125.2 to +82.7) of HIV-1 RNA in arm A versus 2.1 copies ml−1(range −80 to +46.8) in arm B (P=0.024). These results suggest that intermittent HAART tends to modify HIV-1 viraemia set point even if a virological response is achieved after HAART reinstitution.
Conditioned Place Preference Induced by Licit Drugs: Establishment, Extinction, and Reinstatement
Authors: Liu Yu , Le Foll Bernard , Liu Yanli , Wang Xi , Lu Lin
Published: December 2008

The conditioned place preference (CPP) model has been widely used to evaluate the rewarding effects of abused drugs, and recently, the extinction and reinstatement phases of this paradigm have been used to assess relapse to drug seeking. The vast majority of studies have focused on CPP induced by illicit drugs, such as psychostimulants and opioids. Although legal psychoactive drugs, such as ethanol, nicotine, and caffeine, are more widely used than illegal drugs, the establishment, extinction, and reinstatement of CPP produced by these licit drugs are less well understood. The present review discusses the extant research on CPP induced by legal drugs. We first describe the CPP model and discuss the behavioral procedures used to induce CPP for ethanol, nicotine, and caffeine. We then summarize the neuronal substrates that underlie CPP induced by these drugs from a genetic perspective. Finally, we draw on findings from pharmacological studies and discuss the neurotransmitters and neurohormones underlying CPP produced by ethanol, nicotine, and caffeine.
Grazing impact and phenology of the freshwater sponge Ephydatia muelleri and the bryozoans Plumatella emarginata and Fredericella sultana under experimental warming
Authors: VOHMANN ANDREAS , MUTZ MICHAEL , ARNDT HARTMUT , WEITERE MARKUS
Published: December 2008

1. Both the clearance rates (CR) and abundances of the freshwater sponge Ephydatia muelleri and the bryozoans Plumatella emarginata and Fredericella sultana were investigated from autumn to spring under different temperature regimes. The experiments were performed in bypass channels of the River Rhine (Cologne, Germany) in which temperature could be manipulated.

2. The impact of temperature increase on CRs depends upon the grazer: E. muelleri showed a clear increase in CRs with increasing temperature whereas P. emarginata was not significantly affected by experimental warming.

3. Distinct differences in food preference were found for the sponge (which is an efficient grazer of bacteria and small algae) and for the bryozoan P. emarginata (which feeds primarily on large algae, and with no significant grazing on bacteria).

4. In contrast to their temperature‐related patterns in CR, respiration of both P. emarginata and E. muelleri increased with temperature between 19 and 32 °C, suggesting that the risk of experiencing energy deficiency at high temperatures due to increased metabolic rates is particularly high for the bryozoan.

5. A temperature elevation of 3 °C above the natural Rhine temperature resulted in a delay in the disappearance of active tissue and formation of resting stages for E. muelleri in autumn. This delay ranged from 8 (beginning of gemmulation) to 22 days (termination of gemmulation). In contrast, there was no distinct effect of warming on the disappearance of active zooids of the two bryozoan species in autumn. However, warming can positively affect the maintenance of active zooids during winter in F. sultana. In spring, the appearance of active zooids of P. emarginata was clearly stimulated by temperature elevations, whereas the hatching of both F. sultana and E. muelleri was hardly affected by warming.

6. The study demonstrated different patterns in the thermal ecology of the two freshwater bryozoans and the sponge in comparison to other filter feeders, particularly mussels. Such patterns need to be considered when predicting the impact of temperature on pelagic‐benthic coupling in aquatic habitats.
The role of light for fish–zooplankton–phytoplankton interactions during winter in shallow lakes – a climate change perspective
Authors: BRAMM METTE ELISABETH , LASSEN MAJBRITT KJELDAHL , LIBORIUSSEN LONE , RICHARDSON KATHERINE , VENTURA MARC , JEPPESEN ERIK
Published: December 2008

1. Variations in the light regime can affect the availability and quality of food for zooplankton grazers as well as their exposure to fish predation. In northern lakes light is particularly low in winter and, with increasing warming, the northern limit of some present‐day plankton communities may move further north and the plankton will thus receive less winter light.

2. We followed the changes in the biomass and community structure of zooplankton and phytoplankton in a clear and a turbid shallow lake during winter (November–March) in enclosures both with and without fish and with four different light treatments (100%, 55%, 7% and <1% of incoming light).

3. In both lakes total zooplankton biomass and chlorophyll‐a were influenced by light availability and the presence of fish. Presence of fish irrespective of the light level led to low crustacean biomass, high rotifer biomass and changes in the life history of copepods. The strength of the fish effect on zooplankton biomass diminished with declining light and the effect of light was strongest in the presence of fish.

4. When fish were present, reduced light led to a shift from rotifers to calanoid copepods in the clear lake and from rotifers to cyclopoid copepods in the turbid lake. Light affected the phytoplankton biomass and, to a lesser extent, the phytoplankton community composition and size. However, the fish effect on phytoplankton was overall weak.

5. Our results from typical Danish shallow eutrophic lakes suggest that major changes in winter light conditions are needed in order to have a significant effect on the plankton community. The change in light occurring when such plankton communities move northwards in response to global warming will mostly be of modest importance for this lake type, at least for the rest of this century in an IPCC A2 scenario, while stronger effects may be observed in deep lakes.
The demography of coarse wood in north temperate lakes
Authors: MARBURG ANNA E. , BASSAK SARAH B. , KRATZ TIMOTHY K. , TURNER MONICA G.
Published: December 2008

1. Exchange of material across habitat boundaries is a key process in riparian zones. The movement of coarse wood from lakeshore forests to the littoral zone, where it provides habitat for aquatic organisms, is not well understood. In 2003, we resampled coarse wood within the littoral zone of four lakes in Northern Wisconsin (U.S.A.), that had originally been surveyed in 1996, to quantify the spatial arrangement of littoral coarse wood and estimate input, loss and movement rates.

2. All four lakes had a clumped pattern of littoral coarse wood, and the locations of clusters were similar in both census years. Littoral coarse wood was more abundant than expected on moderate to steep slopes, on southern shorelines, and in areas with sparse residential development.

3. All four lakes had a net accumulation of coarse wood; rates of wood input ranged from 0.5 to 1.9 logs km−1 year−1, i.e. there was more wood in 2003 than 1996. Movement rates of tagged logs varied 14‐fold among lakes, with a maximum in one lake of 42% of logs recovered in 2003 more than 20 m from their 1996 location. Median distance moved ranged from 22 to 323 m among the four lakes.

4. Areas of persistently high wood density may be keystone habitats whose presence enables the persistence of populations of certain aquatic organisms. Conservation of locations with high wood density may be important to maintain target densities of coarse wood of lakes with human development.
Low‐frequency symmetric waves in fluid‐filled boreholes and pipes with radial layering
Authors: Sidorov A. , Bakulin A. , Kashtan B. , Ziatdinov S. , Alexandrov D.
Published: December 2008

Many tasks in geophysics and acoustics require estimation of mode velocities in cylindrically layered media. For example, acoustic logging or monitoring in open and cased boreholes need to account for radial inhomogeneity caused by layers inside the borehole (sand screen, gravel pack, casing) as well as layers outside (cement, altered and unaltered formation layers). For these purposes it is convenient to study a general model of cylindrically layered media with inner fluid layer and free surface on the outside. Unbounded surrounding media can be described as a limiting case of this general model when thickness of the outer layer is infinite. At low frequencies such composite media support two symmetric modes called Stoneley (tube) and plate (extensional) wave. Simple expressions are obtained for these two mode velocities valid at zero frequency. They are written in a general form using elements of a propagator matrix describing axisymmetric waves in the entire layered composite. This allows one to apply the same formalism and compute velocities for n‐layered composites as well as anisotropic pipes. It is demonstrated that the model of periodical cylindrical layers is equivalent to a homogeneous radially transversely isotropic media when the number of periods increases to infinity, whereas their thickness goes to zero. Numerical examples confirm good validity of obtained expressions and suggest that even small number of periods may already be well described by equivalent homogeneous anisotropic media.
CD28 and inducible costimulator (ICOS) signalling can sustain CD154 expression on activated T cells
Authors: Kaminski Denise A. , Lee Byung O. , Eaton Sheri M. , Haynes Laura , Randall Troy D.
Published: December 2008

The biological outcome of receptor‐mediated signalling often depends on the duration of engagement. Because CD40 signalling is controlled by the regulated expression of its ligand, CD154, the mechanisms that regulate CD154 expression probably determine the strength and duration of CD40 signalling. Here, we demonstrate that CD154 expression on the surface of mouse CD4 T cells can be separated into an early phase, occurring between 0 and 24 hr after T‐cell activation, and a later extended phase, occurring after 24 hr. The early phase of CD154 expression did not require costimulation and was probably influenced by the strength of T‐cell receptor (TCR) signalling alone. However, later CD154 expression was highly dependent on costimulation through either CD28 or inducible costimulator (ICOS). Although CD28 signalling interleukin (IL)‐2 secretion, ICOS not, suggesting that costimulation enhance CD154 expression independently of IL‐2 production. In fact, anti‐CD28 treatment could still induce late‐phase CD154 on anti‐CD3‐stimulated CD4 T cells expressing a mutated form of CD28 that not lead to the induction of IL‐2. However, this CD154 induction was somewhat weaker than that of wild‐type CD28‐expressing cells, suggesting that direct signalling and IL‐2‐mediated signalling co‐operatively responsible for the levels of CD154 induced by CD28. Finally, we show that the second phase of CD154 expression negatively regulated B‐cell terminal differentiation and antibody secretion. These results demonstrate that TCR signalling and costimulation each regulate different phases of CD154 expression and control the biological outcome of CD40 signalling on B cells.
Transcriptional signatures in response to wheat germ agglutinin and starvation in Drosophila melanogaster larval midgut
Authors: Li H.‐M. , Sun L. , Mittapalli O. , Muir W. M. , Xie J. , Wu J. , Schemerhorn B. J. , Sun W. , Pittendrigh B. R. , Murdock L. L.
Published: December 2008

One function of plant lectins such as wheat germ agglutinin is to serve as defences against herbivorous insects. The midgut is one critical site affected by dietary lectins. We observed marked cellular, structural and gene expression changes in the midguts of Drosophila melanogaster third instar larvae that were fed wheat germ agglutinin. Some of these changes were similar to those observed in the midguts of starved D. melanogaster. Dietary wheat germ agglutinin caused shortening, branching, swelling, distortion and in some cases disintegration of the midgut microvilli. Starvation was accompanied primarily by shortening of the microvilli. Microarray analyses revealed that dietary wheat germ agglutinin evoked differential expression of 61 transcripts; seven of these were also differentially expressed in starved D. melanogaster. The differentially transcribed gene clusters in wheat germ agglutinin‐fed larvae were associated with (1) cytoskeleton organization; (2) digestive enzymes; (3) detoxification reactions; and (4) energy metabolism. Four possible transcription factor binding motifs were associated with the differentially expressed genes. One of these exhibited substantial similarity to MyoD, a transcription factor binding motif associated with cellular structures in mammals. These results are consistent with the hypothesis that wheat germ agglutinin caused a starvation‐like effect and structural changes of midgut cells of D. melanogaster third‐instar larvae.
Comparison of a dietary survey and the duplicate plate method for determining dietary fluoride ingested by young children: a pilot study
Authors: MARTINEZ‐MIER E. ANGELES , KELLY SUE A. , ECKERT GEORGE J. , JACKSON RICHARD D.
Published: December 2008

Background.  Investigators have attempted to establish the diet's contribution to the total body burden of fluoride in response to a reported trend towards an increase in fluoride intake.

Aim.  The aim of this study was to compare the suitability of two methods to collect dietary data for fluoride intake assessment.

Design.  Assessments were made in 12 children using the duplicate plate and dietary diary methods following a randomized cross‐over design. Foods and beverages were analysed for fluoride, and total fluoride intake per day was calculated. Results from each method were compared.

Results.  Mean beverage fluoride intake was estimated at 316 ± 120 and 422 ± 195 µg/day utilizing the diary and duplicate plate methods, respectively. Mean food fluoride intake was estimated at 188 ± 48 µg/day using the diary, whereas it was 130 ± 41 µg using the duplicate plate method. Total fluoride intake was 504 ± 138 and 552 ± 192 µg/day utilizing the diary and duplicate methods. Large variations in daily fluoride intake from both beverages and food were observed between and within children.

Conclusions.  Both methods had inherent shortcomings and sources of error. The duplicate method was more labour intensive and costly; however, the diary method required a large number of assumptions. A combination of both methods seems to be most suitable to obtain reliable data.
Host genetic architecture in single and multiple infections
Authors: WEGNER K. M. , BERENOS C. , SCHMID‐HEMPEL P.
Published: December 2008

Hosts are often target to multiple simultaneous infections by genetically diverse parasite strains. The interaction among these strains and the interaction of each strain with the host was shown to have profound effects on the evolution of parasite traits. Host factors like genetic architecture of resistance have so far been largely neglected. To see whether genetic architecture differs between different kinds of infections we used joint scaling analysis to compare the genetic components of resistance in the red flour beetle Tribolium castaneum exposed to single and multiple strains of the microsporidian Nosema whitei. Our results indicate that additive, dominance and epistatic components were more important in single infections whereas maternal components play a decisive role in multiple infections. In detail, parameter estimates of additive, dominance and epistatic components correlated positively between single and multiple infections, whereas maternal components correlated negatively. These findings may suggest that specificity of host–parasite interactions are mediated by genetic and especially epistatic components whereas maternal effects constitute a more general form of resistance.
Effect of Docosahexaenoic Acid on Quality of Cryopreserved Boar Semen in Different Breeds
Authors: Kaeoket K , Sang‐urai P , Thamniyom A , Chanapiwat P , Techakumphu M
Published: December 2008

Contents

During the cryopreservation process, the level of polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), in the sperm plasma membrane decreases significantly because of lipid peroxidation, which may contribute to sperm loss quality (i.e. fertility) of frozen–thawed semen. The aim of this study was to investigate the effect of supplementation of DHA (fish oil) in freezing extender II on frozen–thawed semen quality. Semen from 20 boars of proven motility and morphology, were used in this study. Boar semen was split into four groups, in which the lactose–egg yolk (LEY) extender used to resuspend the centrifuged sperm pellet was supplemented with various levels of fish oil to reach DHA level of 1X (group I, control, no added fish oil), 6X (group II), 12X (group III) and 18X (group IV). Semen solutions were frozen by using a controlled rate freezer. After cryopreservation, frozen semen was thawed and evaluated for progressive motility, viability by using SYBR‐14/Ethidiumhomodimer‐1 (EthD‐1) staining and acrosome integrity by using FITC‐PNA/EthD‐1 staining. There was a significantly higher (p < 0.001) percentage of progressive motility, viability and acrosome integrity in DHA (fish oil) supplemented groups than control group. Generally, there seemed to be a dose‐dependent effect of DHA, with the highest percentage of progressive motility, viability and acrosome integrity in group‐III. In conclusion, supplementation of the LEY extender with DHA by adding fish oil was effective for freezing boar semen as it resulted in higher post‐thaw plasma membrane integrity and progressive motility.
Efficacy of a Treatment with hCG 4 days After AI to Reduce Pregnancy Losses in Lactating Dairy Cows After Synchronized Ovulation
Authors: Fischer‐Tenhagen C , Thiele G , Heuwieser W , Tenhagen B‐A
Published: December 2008

Content

The objective of the study was to investigate whether a treatment with hCG 4 days after AI could reduce pregnancy losses in lactating dairy cows. Cows of a dairy herd presented to the veterinarian in a fixed reproductive management protocol were treated with an Ovsynch protocol if no corpus luteum (CL) could be palpated per rectum (Group OV). Cows with a CL received cloprostenol (0.15 mg). After 2 days, these cows were treated with buserelin (0.01 mg) and received timed AI 16–20 h later (Group PG). In both treatment protocols, cows were assigned to two groups to receive 2500 IU of hCG i.v. 4 days after AI or to serve as untreated controls (Groups OV‐hCG, OV‐Control, PG‐hCG and PG‐Control). Pregnancy diagnosis was carried out 27 days after AI via ultrasonography and 39 days after AI by rectal palpation. Pregnancy losses were defined as cows being pregnant on day 27 but not pregnant on day 39 after AI. Pregnancy rate (PR) by day 27 did not differ among the four groups (35.4, 35.0, 37.0 and 38.0% for Groups OV‐hCG, OV‐Control, PG‐hCG and PG‐Control, respectively). Pregnancy losses between day 27 and day 39 after AI were smaller in hCG treated animals in summer but not in autumn and spring. Pregnancy rate by day 39 after AI was higher in PG than in OV groups, but independent of hCG‐treatment. In conclusion, treatment with hCG 4 days after AI did not significantly increase PR on 39 days after AI. A positive effect of hCG on pregnancy losses during the summer months warrants further investigation.
Ovarian Follicular Dynamics: A Review with Emphasis on the Bovine Species. Part I: Folliculogenesis and Pre‐antral Follicle Development
Authors: Aerts JMJ , Bols PEJ
Published: December 2008

Contents

Recent scientific research into pre‐antral follicular dynamics has resulted in the discovery of a wide range of hormones and local factors that influence primordial follicle activation and contribute to follicular development. The putative role of several of these mediators in the follicle growth process has been elucidated by genetic and molecular investigations. Crucial questions, such as the mechanism for primordial follicle initiation and the interplay between oocyte and granulosa cells in this process, remain however unresolved. This review article commences with a description of the embryogenesis of the ovary and follicles. Next, the different stages in the development from primordial to pre‐antral follicle are discussed. Thereafter, a short overview of the various in vitro models for the study of follicular dynamics is presented. Finally, an in‐depth discussion of pre‐antral follicle development engages in the current hypotheses regarding primordial follicle activation, and the role of gonadotrophins and angiogenesis.
AN AuTOPSY CASE OF IMPETIGO HERPETIFORMIS HEBRA
Authors: Fukuda Yoshiro , Yoshizawa Hisayoshi , Shimada Hiroyuki
Published: December 2008

A 24 years old male case who died of suicide in a peak of Impetigo herpetiformis was reported. Initially he developed skin eruptions at the age of 6 years. During the last twenty‐three months, skin eruptions relapsed sixteen times. Intensive therapy of adreno‐cortical hormone, sex hormone and antibiotics were given. Pathological findings of endocrine and genital organs were considered to be caused by the intensive hormone therapy, No etiological finding was found in internal organs pathologically. Staphylococci aureus and epidermis were found only once in blood, twice in the pustules. However, secondary infection could not be ruled out. This case indicated that I.h. was a disease of only skin.
MOTOR NEURON DISEASE REPORT OF TWO CASES
Authors: Isida Yoiti , Kawai Sadao , Nagasima Isamu , Sato Kazuo , Niibe Hideo , Takeda Fumikazu
Published: December 2008

Two autopsy cases of moter neuron disease, progressive spinal muscular atrophy and amyotrophic lateral sclerosis, were presented. In both cases, the process was essentially degenerative with selective or predominant involvement of motor neuron system. Topographical studies, however, revealed unusual concomitants, involvement of the upper neuron in the former case and of extra pyramidal motor nuclei in the latter. No factors of etiological significance was demonstrated.
THROMBOTIC MICROANGIOPaTHY IN PaTIENTS WITH MALIGNANT TUMOR
Authors: Komori Ryo
Published: December 2008

1. Three cases of thrombotic thrombocytopenic purpura associated with malignancies, leukemia in one case and gastric carcinoma in two cases are reported.

2. Using the fluorescent antibody method, it is concluded that the thrombi of arterioles and capillaries in these cases are composed of platelets and fibrin (or fibrinogen).

3. The pathogenic mechanism of thrombotic microangiopathy associated with malignancies is discussed.
A CASE OF DIPROSOPUS
Authors: Arai Tsuneto , Masaki Shin , Nikaido Masakazu
Published: December 2008

Diprosopus monauchenos tetrophthalmus triotus monoris, which is a rare malformation, was reported. This diprosopus was delivered from a 38 years old primipara and was accompanied by acrania, encephalomeningocele, duplication of spinal column and rachischisis.
Electron Microscopic Study on Normal Rat Peritoneal Mesothelium and its Changes in Absorption of Particulate Iron Dextran Complex
Authors: Fukata Hiroji
Published: December 2008

Abstract

Fine structures of peritoneal mesothelium of normal rat omentum and its changes in absorption of iron dextran complex were studied by means of electron microscope. Peritoneal mesothelium resembles endothelial sheet of blood‐ and lymph‐vessels without specific pores, and also has abundant pinocytic vesicles throughout the cytoplasm. In the mesothelium of both normal and experimental cases, there are no free openings comparable to “Stomata or Stigmata”, on the existence of which many observers have discussed from the findings in photo‐ microscopic studies. Iron dextran particles injected intraperitoneally seem to be able to pass through the cytoplasm of the cell and can enter the interstitial space by “Transmembranation (Tanaka) or Diffusion” as well as “Pinocytosis”.

A part of them are gathered within membrane closed round vesicles (Segresomes, Tanaka) by a phagocyte‐like action of the mesothelial cells.
HISTOCHEMICAL STUDIES ON ACHD MUCOPOLYSACCHARIDES
Authors: Sugiyama Taketoshi
Published: December 2008

Some new methods for demonstration and differentiation of acid mucopolysaccharides were described.

Cationic surfactive resin‐azo dye method could be used for all kinds of acid mucopolysaccharide demonstration.

Neutral red method was found to differentiate sulfated and non‐sulfated groups on one section.

Two principles to identify keratosulfate in mesenchymal tissues were studied;

Hyaluronidase‐methylation‐saponification method can differentiate keratosulfate B which are both sensitive to testicular hyaluronidase.

Sugar reactions: Molisch reaction, carbazol‐sulfuric acid reaction, etc. can demonstrate the presence of galactose‐containing keratosulfate in the frozen sections.

By using these together with well established methods a differential table was made.

The author is deeply grateful to Dr. SHIDA and Dr. KUSHIDA of the General Institute for Medical Biochemistry, Kyoto, Kowa Co., Kaken Yakukako Co., and Hodogaya Chemical Industry Co. for the supply of several kinds of samples.
AN AUTOPSY CASE OF CONGENITAL APLASTIC ANEMIA ASSOCIATED WITH INTENSIVE HYPOPLASIA OF THYMUS GLAND*
Authors: Utsumi Kunisuke , Kuribayashi Nobuo
Published: December 2008

The authors have reported an autopsy case of congenital aplastic anemia associated with intensive hypoplasia of thymus gland and treated with a large amount of fresh blood transfusion and corticosteroids.

There were complete fatty change of the bone marrows, intensive general anemia and hemorrhagic diathesis, intensive hypoplasia of the thymus gland, marked atrophy of the spleen, lymph nodes and other lymphatic tissues, and calcified foci with hemorrhagic softening of the brain.

As to the pathogenesis, a close similarity of the present case with those reported by De Vaal, Hitzig and Gitlin was pointed out. The authors regard that there is an undeniable close relation between congenital aplastic anemia and thymic hypoplasia.
HUMAN CYTOMEGALOVIRUS INFECTION: ELECTRON AND LIGHT MICROSCOPIC OBSERVATIONS OF THE PAROTID GLANDS OF AN AUTOPSY CASE
Authors: Kawanishi Hidenori , Takeda Toshio , Matsumoto Masao
Published: December 2008

HCMV infection in the parotid gland removed at autopsy from a 5‐month‐old male infant with generalized cytomegalic inclusion disease was investigated electron‐ and light‐ microscopically, and virus invasion, synthesis and release in the host cell were described and compared with the results of in vivo experiments previously reported.

In the infected nucleus several types of inclusions were formed, and a virus‐synthesizing matrix was seen to produce numerous developmental forms of the virus, usually with, but infrequently without, a variable core. Three unusual structures were seen in the nucleus of cytomegalic inclusion cells! tortuous strings, bamboo‐like virus‐synthesizing bodies and intranuclear sacs containing vesicles. The coat of mature HCMV in the cytoplasm appeared to be a triple‐layered structure. The release of viruses into the parotid glandular lumen occurred by emiocytosis.