bluuebunny/crossref_metadata_2025 huggingface dataset:
Nitrogen dynamics and red pine growth following application of pelletized biosolids in Massachusetts, USA
Authors: Kelty Matthew J , Menalled Fabián D , Carlton Maggie M
Published: August 2004

Pelletized biosolids from municipal wastewater treatment were applied to a thinned red pine plantation to determine if there were treatment levels that could produce a fertilization growth response without resulting in unacceptable nitrate leaching. The pellets (total nutrient concentrations of 4.4% N, 1.4% P, 0.2% K) were applied at four levels (0, 200, 400, 800 kg/ha total N). Only 26% of labile organic N in the pellets was mineralized in the first year after application. Foliar N increased with increasing application rate, but other nutrients were unchanged. Red pine basal area growth was unchanged with low and medium levels, but decreased to 50% of control plots with the highest level. A decrease in foliar K/N ratio resulting from high N uptake with little additional K is hypothesized as the cause for the growth decline. The highest treatment level resulted in lysimeter nitrate-N concentrations increasing to 2 mg/L in the first year and 9 mg/L in the second, returning to control levels in the third; no increase occurred in other treatments. These results contrast with those found with liquid sludge applications, in which nearly all N mineralization and the highest nitrate leaching rates occurred in the first year. The slower release of inorganic N from pellets over 2 years may allow higher total N application rates without causing high nitrate leaching.
QUANTUM GRAVITY PHENOMENOLOGY, LORENTZ INVARIANCE AND DISCRETENESS
Authors: DOWKER FAY , HENSON JOE , SORKIN RAFAEL D.
Published: August 2004

Contrary to what is often stated, a fundamental spacetime discreteness need not contradict Lorentz invariance. A causal set's discreteness is in fact locally Lorentz invariant, and we recall the reasons why. For illustration, we introduce a phenomenological model of massive particles propagating in a Minkowski spacetime which arises from an underlying causal set. The particles undergo a Lorentz invariant diffusion in phase space, and we speculate on whether this could have any bearing on the origin of high energy cosmic rays.
QUASIPARTICLE UNIVERSES IN BOSE–EINSTEIN CONDENSATES
Authors: FISCHER UWE R.
Published: August 2004

Recent developments in simulating fundamental quantum field theoretical effects in the kinematical context of analogue gravity are reviewed. Specifically, it is argued that a curved spacetime generalization of the Unruh–Davies effect — the Gibbons–Hawking effect in the de Sitter spacetime of inflationary cosmological models — can be implemented and verified in an ultracold gas of bosonic atoms.
LOOKING FOR THE CHARGED HIGGS BOSON
Authors: ROY D. P.
Published: August 2004

This review starts with a brief introduction to the charged Higgs boson (H±) in the Minimal Supersymmetric Standard Model (MSSM). It then discusses the prospects of a relatively light H± boson search via top quark decay at Tevatron/LHC, and finally a heavy H± boson search at LHC. The viable channels for H± search are identified in both the cases, with particular emphasis on the H±→τν decay channel. The effects of NLO QCD correction in the SM as well as the MSSM are discussed briefly.
SEVERAL RELATED MODELS FOR MULTILAYER SANDWICH PLATES
Authors: HANSEN SCOTT W.
Published: August 2004

Mathematical models for multilayer sandwich plates consisting of alternating stiff and compliant layers are derived. Two main types of models are described. First an initial model (analogous to the three-layer Rao–Nakra model) is derived under Kirchhoff plate assumptions for the stiff layers and Mindlin shear-deformable displacement assumptions for the compliant layers. The second type of model can be obtained from the original model by dropping the in-plane and rotational inertia. The resulting model is a generalization of the well-known model of Mead and Markus. Well-posedness and continuous parameter dependence results are described. Some variations of the initial model corresponding to thin compliant layers are described and shown to be regular perturbations of the initial model.
A CELL-CENTERED SECOND-ORDER ACCURATE FINITE VOLUME METHOD FOR CONVECTION–DIFFUSION PROBLEMS ON UNSTRUCTURED MESHES
Authors: BERTOLAZZI ENRICO , MANZINI GIANMARCO
Published: August 2004

A MUSCL-like cell-centered finite volume method is proposed to approximate the solution of multi-dimensional steady advection–diffusion equations. The second-order accuracy is provided by an appropriate definition of the diffusive and advective numerical fluxes. The method is based on a least squares reconstruction of the vertex values from cell averages. The slope limiter, which is required to prevent the formation and growth of spurious numerical oscillations, is designed to guarantee that the discrete solution of the nonlinear scheme exists. Several theoretical issues regarding the solvability of the resulting discrete problems are thoroughly discussed. Finally, numerical experiments that validate the effectiveness of the approach are presented.
Trafficking of cholera toxin-ganglioside GM1 complex into Golgi and induction of toxicity depend on actin cytoskeleton
Authors: Badizadegan Kamran , Wheeler Heidi E. , Fujinaga Yukako , Lencer Wayne I.
Published: August 2004

Intestinal epithelial lipid rafts contain ganglioside GM1 that is the receptor for cholera toxin (CT). The ganglioside binds CT at the plasma membrane (PM) and carries the toxin through the trans-Golgi network (TGN) to the endoplasmic reticulum (ER). In the ER, a portion of the toxin unfolds and translocates to the cytosol to activate adenylyl cyclase. Activation of the cyclase leads to an increase in intracellular cAMP, which results in apical chloride secretion. Here, we find that an intact actin cytoskeleton is necessary for the efficient transport of CT to the Golgi and for subsequent activation of adenylyl cyclase. CT bound to GM1 on the cell membrane fractionates with a heterogeneous population of lipid rafts, a portion of which is enriched in actin and other cytoskeletal proteins. In this actin-rich fraction of lipid rafts, CT and actin colocalize on the same membrane microdomains, suggesting a possible functional association. Depolymerization or stabilization of actin filaments interferes with transport of CT from the PM to the Golgi and reduces the levels of cAMP generated in the cytosol. Depletion of membrane cholesterol, which also inhibits CT trafficking to the TGN, causes displacement of actin from the lipid rafts while CT remains stably raft associated. On the basis of these observations, we propose that the CT-GM1 complex is associated with the actin cytoskeleton via the lipid rafts and that the actin cytoskeleton plays a role in trafficking of CT from the PM to the Golgi/ER and the subsequent activation of adenylyl cyclase.
Regulation of dihydropyridine receptor gene expression in mouse skeletal muscles by stretch and disuse
Authors: Radzyukevich Tatiana L. , Heiny Judith A.
Published: August 2004

This study examined dihydropyridine receptor (DHPR) gene expression in mouse skeletal muscles during physiological adaptations to disuse. Disuse was produced by three in vivo models—denervation, tenotomy, and immobilization—and DHPR α1s mRNA was measured by quantitative Northern blot. After 14-day simultaneous denervation of the soleus (Sol), tibialis anterior (TA), extensor digitorum longus (EDL), and gastrocnemius (Gastr) muscles by sciatic nerve section, DHPR mRNA increased preferentially in the Sol and TA (+1.6-fold), whereas it increased in the EDL (+1.6-fold) and TA (+1.8-fold) after selective denervation of these muscles by peroneal nerve section. It declined in all muscles (−1.3- to −2.6-fold) after 14-day tenotomy, which preserves nerve input but removes mechanical tension. Atrophy was comparable in denervated and tenotomized muscles. These results suggest that factor(s) in addition to inactivity per se, muscle phenotype, or associated atrophy can regulate DHPR gene expression. To test the contribution of passive tension to this regulation, we subjected the same muscles to disuse by limb immobilization in a maximally dorsiflexed position. DHPR α1s mRNA increased in the stretched muscles (Sol, +2.3-fold; Gastr, +1.5-fold) and decreased in the shortened muscles (TA, −1.4-fold; EDL, −1.3-fold). The effect of stretch was confirmed in vitro. DHPR protein did not change significantly after 4-day immobilization, suggesting that additional levels of regulation may exist. These results demonstrate that DHPR α1s gene expression is regulated as an integral part of the adaptive response of skeletal muscles to disuse in both slow- and fast-twitch muscles and identify passive tension as an important signal for its regulation in vivo.
Diet-induced hyperphagia in the rat is influenced by sex and exercise
Authors: Eckel Lisa A. , Moore Shelley R.
Published: August 2004

Caloric intake is increased in rats fed a diet containing greater fat or sugar than that found in laboratory chow. Because such diet-induced hyperphagia has been studied primarily in sedentary male rats, our goal here was to investigate the effects of sex and exercise on caloric intake of a diet (chow supplemented with sweet milk) chosen for its ability to stimulate hyperphagia. Rats were housed individually in cages that provided access to running wheels, and daily caloric intake of chow alone and then chow plus sweet milk was monitored during sedentary and active conditions. In sedentary rats, chow intake was greater in males compared with females. Wheel running produced similar decreases in chow intake in both sexes. Availability of the chow plus milk diet increased caloric intake compared with that observed in chow-fed rats. This diet-induced hyperphagia was significantly greater in sedentary females (35.7 ± 3.1% increase) relative to sedentary males (9.1 ± 2.2% increase). In addition, 35% of sedentary females consuming the chow plus milk diet developed estrous cycle disruptions. Wheel running decreased intake of the chow plus milk diet in both sexes. In active males, diet-induced hyperphagia was abolished; caloric intake was reduced to that observed during chow feeding. In active female rats, diet-induced hyperphagia was attenuated but not abolished; caloric intake of the chow plus milk diet remained greater than that observed during chow feeding. We conclude that female rats are more vulnerable than male rats to this form of diet-induced hyperphagia.
Selectivity for the Human Body in the Fusiform Gyrus
Authors: Peelen Marius V. , Downing Paul E.
Published: August 2004

Functional neuroimaging studies have revealed human brain regions, notably in the fusiform gyrus, that respond selectively to images of faces as opposed to other kinds of objects. Here we use fMRI to show that the mid-fusiform gyrus responds with nearly the same level of selectivity to images of human bodies without faces, relative to tools and scenes. In a group-average analysis ( n = 22), the fusiform activations identified by contrasting faces versus tools and bodies versus tools are very similar. Analyses of within-subjects regions of interest, however, show that the peaks of the two activations occupy close but distinct locations. In a second experiment, we find that the body-selective fusiform region, but not the face-selective region, responds more to stick figure depictions of bodies than to scrambled controls. This result further distinguishes the two foci and confirms that the body-selective response generalizes to abstract image formats. These results challenge accounts of the mid-fusiform gyrus that focus solely on faces and suggest that this region contains multiple distinct category-selective neural representations.
Deficits in Movements of the Wrist Ipsilateral to a Stroke in Hemiparetic Subjects
Authors: Yarosh Cherylon A. , Hoffman Donna S. , Strick Peter L.
Published: August 2004

We examined step-tracking movements of the wrist and associated EMG activity in seven patients (age range, 27–73 yr) and in seven normal subjects that were matched to patients in age, sex, and handedness. All patients exhibited a hemiparesis that resulted from a unilateral cerebrovascular accident (CVA) that included motor areas in the frontal lobe or their efferents. The lesion in three patients was in their dominant hemisphere. The patients were tested 1–48 mo following their CVA. They had great difficulty in performing or were unable to perform step-tracking movements with the contralesional wrist. In addition, the patients displayed striking deficits in wrist movements and muscle activity of the ipsilesional wrist. These movements were >50% slower than those of controls. The initial movement step routinely undershot the target and was only 63% as large as that of controls. The patients made wrist movements with marked directional errors requiring corrective responses. These errors were due largely to inappropriate temporal sequencing of muscle activity. The deficits in movement and muscle activity in the wrist ipsilesional to a CVA were marked, regardless of whether the lesion was in the dominant or nondominant hemisphere. These observations indicate that unilateral lesions can have significant bilateral effects on the generation and control of distal limb movements.
Continuity for some multilinear operators of integral operators on Triebel‐Lizorkin spaces
Authors: Lanzhe Liu
Published: August 2004

The continuityfor some multilinear operators related to certain
fractional singular integral operators on Triebel‐Lizorkin spaces is obtained. The operators include
Calderon‐Zygmund singular integral operator and fractional
integral operator.
Optimal order yielding discrepancy principle for simplified regularization in Hilbert scales: finite‐dimensional realizations
Authors: George Santhosh , Nair M. Thamban
Published: August 2004

Simplified regularization using finite‐dimensional approximations in the setting of Hilbert scales has been considered for obtaining stable approximate solutions to ill‐posed operator equations. The derived error estimates using an a priori and a posteriori choice of parameters in relation to the noise level are shown to be of optimal order with respect to certain natural assumptions on the ill posedness of the equation. The results are shown to be applicable to a wide class of spline approximations in the setting of Sobolev scales.
Conditional resolvability in graphs: a survey
Authors: Saenpholphat Varaporn , Zhang Ping
Published: August 2004

For an ordered set W = {w1, w2, …, wk} of vertices and
a vertex v in a connected graph G, the code of v with
respect to W is the k‐vector cW(v) = (d(v, w1), d(v, w2), …, d(v, wk)), where d(x, y) represents the distance
between the vertices x and y. The set W is a resolving set
for G if distinct vertices of G have distinct codes with
respect to W. The minimum cardinality of a resolving set for
G is its dimension dim(G). Many resolving parameters are
formed by extending resolving sets to different subjects in graph
theory, such as the partition of the vertex set, decomposition
and coloring in graphs, or by combining resolving property with
another graph‐theoretic property such as being connected,
independent, or acyclic. In this paper, we survey results and
open questions on the resolving parameters defined by imposing an
additional constraint on resolving sets, resolving partitions, or
resolving decompositions in graphs.
Assessment of the Automobile Assembly Paint Process for Energy, Environmental, and Economic Improvement
Authors: Roelant Geoffrey J. , Kemppainen Amber J. , Shonnard David R.
Published: August 2004

A coat of paint adds considerable value to an automobile. In addition to consuming up to 60% of the energy needed by automobile assembly plants, however, the painting process also creates both economic and environmental impacts. This study investigated the degree of cost and environmental impact improvement that can be expected when modifications are considered for existing paint processes through heat integration. In order to accomplish this goal, a mathematical model was created to describe the energy use, costs, and environmental impacts from energy consumption in an automobile assembly painting facility. The model agrees with measured energy consumption data for process heating and electricity demand to within about 15% for one Michigan truck facility from which model input parameters were obtained. Thermal pinch analysis determined an energy conservation target of 58% of paint process energy demand. A heat exchanger network optimization study was conducted in order to determine how closely the network design could achieve this target. The resulting heat exchanger network design was profitable based on a discounted cash flow analysis and may achieve reductions in total corporate energy consumption of up to 16% if implemented corporatewide at a major automobile manufacturer.
Decision Analysis Utilizing Data from Multiple Life‐Cycle Impact Assessment Methods: Part II: Model Development
Authors: Rahimi Mansour , Weidner Merrill
Published: August 2004

In this (two‐part) series of articles, we develop and present a series of life‐cycle‐assessment‐based (LCA‐based) decision analysis models, based on multiattribute value theory (MAVT), which utilize data from multiple life‐cycle impact assessment (LCIA) methods and/or levels of analysis. In part I of this series, we began the task of developing a theoretically sound decision analysis methodology for accomplishing this. We also provided a preliminary introduction to the concept of proxy attributes, which are central to our overall methodological approach. In this part, we expand the decision analysis model developed previously to include (1) the combination of end‐point indicators from multiple LCIA methods, (2) the combination of midpoint indicators, and (3) the combination of multiple end‐point and midpoint damage indicators in a single decision model. In our models, we consider the LCIA damage indicators to be proxy attributes for actual consequences. In order to combine the LCIA indicators (as proxy attributes) from multiple methods, the decision maker must make a combination of value‐ and factual‐based judgments concerning the actual consequences associated with the proxy attributes. We address the imprecise relationship between damage indicators and actual consequences in a way that we believe to be more appealing to most decision makers, based on linguistic variables (e.g., “much greater”) represented as fuzzy variables. By utilizing the methodological approaches presented here and in part I, an LCA practitioner or decision maker can construct theoretically based decision models utilizing damage indicators (including both end points and midpoints) from any combination of LCIA methods. Given the inherent limits of LCIA, we believe that decision models developed on this basis provide for better and more informed decision making, through the explicit assessment and treatment of individual decision‐maker preferences and the additional information provided through the use of data from multiple LCIA methods.
Energy Consumption in the Danish Fishery: Identification of Key Factors
Authors: Thrane Mikkel
Published: August 2004

Previous studies based on life‐cycle assessment (LCA) in Denmark and Sweden have shown that the fishery is the environmental “hot spot” in the life cycle of certain fish products. Within the fishery, fuel consumption is one of the most important factors addressed by LCA. The present study reveals that there are great differences in fuel consumption between fisheries targeting groundfish or shellfish and those targeting pelagic fish or industrial fish. Here, I show that fuel consumption per kilogram of caught fish varies considerably as a function of fishing gear and vessel size, even considering the same target species. I argue that these differences need to be addressed in the search for a fuel‐efficient fishery. Improvements in fuel efficiency may be consistent with other objectives, such as reduced impacts on seafloor habitats and reduced discard.
Preliminary inventory and classification of indigenous afromontane forests on the Blyde River Canyon Nature Reserve, Mpumalanga, South Africa
Authors: Lötter Mervyn C , Beck Hans T
Published: August 2004

Background

Mixed evergreen forests form the smallest, most widely distributed and fragmented biome in southern Africa. Within South Africa, 44% of this vegetation type has been transformed. Afromontane forest only covers 0.56 % of South Africa, yet it contains 5.35% of South Africa's plant species. Prior to this investigation of the indigenous forests on the Blyde River Canyon Nature Reserve (BRCNR), very little was known about the size, floristic composition and conservation status of the forest biome conserved within the reserve. We report here an inventory of the forest size, fragmentation, species composition and the basic floristic communities along environmental gradients.

Results

A total of 2111 ha of forest occurs on Blyde River Canyon Nature Reserve. The forest is fragmented, with a total of 60 forest patches recorded, varying from 0.21 ha to 567 ha in size. On average, patch size was 23 ha. Two forest communities – high altitude moist afromontane forest and low altitude dry afromontane forest – are identified. Sub-communities are recognized based on canopy development and slope, respectively. An altitudinal gradient accounts for most of the variation within the forest communities.

Conclusion

BRCNR has a fragmented network of small forest patches that together make up 7.3% of the reserve's surface area. These forest patches host a variety of forest-dependent trees, including some species considered rare, insufficiently known, or listed under the Red Data List of South African Plants. The fragmented nature of the relatively small forest patches accentuates the need for careful fire management and stringent alien plant control.
Effect of haemoperfusion on plasma paraquat concentration in vitro and in vivo
Authors: Hong Sae-Yong , Yang Jong-Oh , Lee Eun-Young , Kim Soo-Hyun
Published: August 2004

This study was to observe the paraquat (PQ) reduction rate after haemoperfusion (HP) on the groups of a relatively large number: 50 survivors out of 105 patients with acute PQ poisoning. We started off by measuring the clearance of haemodialysis (HD) and HP for the PQ in vitro. At the blood flow of 250 mL/min, the PQ clearance was greater in HP than in HD during the first 90 minutes: 215 versus 175 mL/min at 30 minutes, 213 versus 201 mL/min at 60 minutes, and 199 versus 179 mL/min at 90 minutes. The clearance in HP decreased rapidly after two hours. By the end of the dialysis, however, the final concentration in container decreased to 5.7 mg/mL in HD and 1.5 mg/mL in HP, which implied that although HD was cleared more effectively during the later stages, the overall elimination was greater in HP. Following this preliminary investigation, we performed HP on all the patients in order to assess the extracorporeal elimination.

One hundred and five patients who had swallowed one to three mouthfuls of PQ (24.5% w/v) solution were subjected to the in vivo study. The reduction rate of PQ was checked out by measuring the PQ concentration in plasma before and after four hours of HP. Seeing the reduction rate was significantly higher in the survivors group than in the nonsurvivors group (80.39 ± 19.9 versus 67.29 ± 19.2%, P <0.01), we concluded that adequate HP appears to be an indispensable treatment for patients with acute PQ poisoning.
Effects of active sunscreen ingredient combinations on the topical penetration of the herbicide 2,4-dichlorophenoxyacetic acid
Authors: Pont Adam R , Charron Anna R , Wilson Roselyn M , Brand Rhonda M
Published: August 2004

Sunscreen use can reduce the incidence of certain skin cancers. However, a number of commercially available formulations have been shown to enhance the transdermal penetration of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). Most of the active ingredients used in these compounds can individually act as penetration enhancers. Commercial sunscreens frequently contain multiple active ingredients in order to provide broad sunscreen protection. The purpose of this study was therefore to examine the effect of these active ingredient combinations on the transdermal absorption of 2,4-D in vitro. All six of the combinations tested resulted in increased cumulative penetration ( P <0.01) and faster lag times ( P <0.05). The 2,4-D cumulative penetration in the presence of the OFF! Deepwoods combination was significantly greater than the absorption with either the individual ingredients or their average ( P <0.05). A systematic study designed to isolate the chemicals responsible for this enhancement demonstrated that with UV absorbers DEET synergistically increased the 2,4-D penetration and that DEET’s cumulative enhancement properties correlate with its concentration. By contrast, octocrylene significantly slowed the lag time when used in combinations and was the only active ingredient that showed any antagonistic effects on 2,4-D penetration. Because none of the active ingredient combinations were able to inhibit dermal uptake of 2,4-D, it seems that proper selection of inert ingredients may be the most feasible solution for reducing penetration enhancement.
TRA-1/GLIcontrols development of somatic gonadal precursors inC. elegans
Authors: Mathies Laura D. , Schvarzstein Mara , Morphy Kristin M. , Blelloch Robert , Spence Andrew M. , Kimble Judith
Published: August 2004

TRA-1/GLI is best known as a master regulator of sex determination in the nematode C. elegans, but its fly and vertebrate homologs (e.g. Ci,GLI) regulate embryonic patterning and cell proliferation. In this paper, we show that TRA-1/GLI controls development of the two somatic gonadal precursors(SGPs) in both XX and XO animals, in addition to its role in sex determination. Normally, SGPs reside at the poles of the gonadal primordium and divide according to intrinsic gonadal axes. In tra-1-null mutants, however, SGPs assume non-polar positions and the polarity of one SGP is reversed. Consistent with its SGP function, TRA-1 protein is present in SGPs during embryogenesis and early larval development. Previous studies have shown that the ehn-3 gene also affects SGP positions, and we report here that tra-1 and ehn-3 interact genetically. Whereas SGPs in tra-1 and ehn-3 single mutants are largely normal and generate many descendants, those in tra-1; ehn-3 double mutants do not mature or divide. Furthermore, tra-1 is a dominant enhancer of the ehn-3 gonadal defect, which includes the enhancement of a weak sexual transformation in the gonad. We cloned ehn-3, and found that it encodes a C2H2 zinc-finger protein. A rescuing EHN-3::GFP reporter is predominantly nuclear and expressed specifically in SGPs. The EHN-3 protein is therefore likely to regulate gene expression. We propose that TRA-1/GLI and EHN-3 have overlapping roles in regulation of multiple steps of SGP development. We speculate that regulation of SGP development may be an evolutionarily ancient role of TRA-1/GLI in nematode development.
Insulin acts as a myogenic differentiation signal for neural stem cells with multilineage differentiation potential
Authors: Bani-Yaghoub Mahmud , Kendall Stephen E. , Moore Daniel P. , Bellum Stephen , Cowling Rebecca A. , Nikopoulos George N. , Kubu Chris J. , Vary Calvin , Verdi Joseph M.
Published: August 2004

Reports of non-neural differentiation of neural stem cells (NSCs) have been challenged by alternative explanations for expanded differentiation potentials. In an attempt to demonstrate the plasticity of NSC, neurospheres were generated from single retrovirally labeled embryonic cortical precursors. In a defined serum-free insulin-containing media, 40% of the neurospheres contained both myogenic and neurogenic differentiated progeny. The number of NSCs displaying multilineage differentiation potential declines through gestation but does exist in the adult animal. In this system, insulin appears to function as a survival and dose-dependent myogenic differentiation signal for multilineage NSCs (MLNSC). MLNSC-derived cardiomyocytes contract synchronously, respond to sympathetic and parasympathetic stimulation, and regenerate injured heart tissues. These studies provide support for the hypothesis that MLNSCs exist throughout the lifetime of the animal, and potentially provide a population of stem cells for cell-based regenerative medicine strategies inside and outside of the nervous system.
Identification and in vivo role of the Armadillo-Legless interaction
Authors: Hoffmans Raymond , Basler Konrad
Published: August 2004

The Wnt signalling system controls many fundamental processes during animal development and its deregulation has been causally linked to colorectal cancer. Transduction of Wnt signals entails the association of β-catenin with nuclear TCF DNA-binding factors and the subsequent activation of target genes. Using genetic assays in Drosophila, we have recently identified a presumptive adaptor protein, Legless (Lgs), that binds toβ-catenin and mediates signalling activity by recruiting the transcriptional activator Pygopus (Pygo). Here, we characterize theβ-catenin/Lgs interaction and show: (1) that it is critically dependent on two acidic amino acid residues in the first Armadillo repeat ofβ-catenin; (2) that it is spatially and functionally separable from the binding sites for TCF factors, APC and E-cadherin; (3) that it is required in endogenous as well as constitutively active forms of β-catenin for Wingless signalling output in Drosophila; and (4) that in its absence animals develop with the same phenotypic consequences as animals lacking Lgs altogether. Based on these findings, and because Lgs and Pygo have human homologues that can substitute for their Drosophila counterparts, we infer that the β-catenin/Lgs binding site may thus serve as an attractive drug target for therapeutic intervention in β-catenin-dependent cancer progression.
Synergistic and antagonistic roles of the Sonic hedgehog N- and C-terminal lipids
Authors: Feng Jianchi , White Bryan , Tyurina Oksana V. , Guner Burcu , Larson Theresa , Lee Hae Young , Karlstrom Rolf O. , Kohtz Jhumku D.
Published: August 2004

The Shh protein contains both N-terminal and C-terminal lipids. The functional redundancy of these lipid moieties is presently unclear. Here, we compare the relative roles of the N- and C-terminal lipids in early rat striatal neuronal differentiation, membrane association and multimerization,and ventralizing activity in the zebrafish forebrain. We show that these lipid act synergistically in cell tethering and the formation of a large (L)multimer (669 kDa). However, the C-terminal lipid antagonizes the rat striatal neuronal differentiation-inducing activity of the N-terminal lipid. In addition, multimerization is required but not sufficient for the differentiation-inducing activity. Based on the presence of different N- and C-lipid-containing Shh proteins in the rat embryo, and on their different activities, we propose that both N- and C-terminal lipids are required for the formation of multimers involved in long-range signaling, and that the C-terminal lipid may function in long-range signaling by reducing Shh activity until it reaches its long-range target. Comparative analysis of the ventralizing activities of different N- and C-terminal lipid-containing Shh proteins in the zebrafish forebrain shows that the presence of at least one lipid is required for signaling activity, suggesting that lipid modification of Shh is a conserved requirement for signaling in the forebrain of rodents and zebrafish.
A study on the characteristics of combustion with butane and propane in a retrofitted diesel engine
Authors: Choi Gyeung Ho , Bae Seok Choun , Han Sung Bin , Chung Yong Jong
Published: August 2004

The purpose of this study was to investigate the characteristics of combustion and exhaust-gas temperature of a liquefied petroleum gas (LPG) engine when using butane and propane as fuel. A conventional diesel engine was modified into a LPG engine that utilized an LPG fuel system instead of a diesel fuel injection pump. The study was performed with different compositions of butane and propane, such as 100 per cent butane, 100 per cent propane, 50 per cent butane—50 per cent propane, 70 per cent butane—30 per cent propane, and 30 per cent butane—70 per cent propane. The major conclusions of this work are as follows: MBT spark ignition timing was similar with different butane/propane fuel blends, except at the 100 per cent butane, 1200 r/min condition; engine torque and power were not influenced by varying butane/propane fuel blends; and exhaust gas temperature was increased at higher engine speeds, and it was decreased by a maximum of 15 with different butane/propane fuel blends.
Development of a piezoelectrically-controlled hydraulic actuator for a camless engine. Part 1: System design
Authors: Brader J S , Rocheleau D N
Published: August 2004

A camless engine proof-of-concept prototype was completed on the basis of the use of piezoelectric control of a hydraulic actuator. This novel approach was taken in an attempt to enhance earlier solenoid-based camless engine prototypes, several of which are reviewed as an introduction to camless engine technology. Following a historical review, an overview of the piezoelectrically- controlled camless engine actuator is discussed. The prototype system is capable of displacing an engine valve up to 12.4 mm, and valve actuation frequencies of up to 500 Hz have been obtained. The proof of concept can be considered successful, as it demonstrates the potential of piezoelectric control of hydraulics for use as an internal combustion engine valve actuator. Furthermore, in conjunction with variable timing, the piezoelectric control based pilot allows for direct regulation of other engine valve parameters including variable lift and seating velocity.
Interpretation of infrared spectra of dioctahedral smectites in the region of OH-stretching vibrations
Authors: Zviagina Bella B. , McCarty Douglas K. , Środoń Jan , Drits Victor A.
Published: August 2004

Dioctahedral smectite samples of a wide range of compositions (beidellites, montmorillonites, nontronites, Fe-rich montmorillonites and Al-rich nontronites) were studied by infrared (IR) spectroscopy. A special sample-preparation technique was used to eliminate the contribution of molecular water. The OH-stretching regions of the spectra were decomposed and curve-fitted, and the individual OH-stretching bands were assigned to all the possible types of OH-bonded cation pairs that involve Al, Mg and Fe. The integrated optical densities of the OH bands were assumed to be proportional to the contents of the specific types of OH-linked cation pairs with the absorption coefficients being the same for all individual OH bands. Good agreement between the samples’ octahedral cation compositions calculated from the IR data and those given by crystal-chemical formulae was obtained for a representative collection of samples in terms of a unique set of individual OH-band positions that vary within narrow wavenumber intervals. This has allowed us to minimize the ambiguity in spectra decomposition caused by the poor resolution of smectite spectra and confirmed the validity of the resulting band identification.

The bands associated with specific OH-bonded cation pairs in the spectra of smectites are, on the whole, shifted to greater wavenumbers with respect to the corresponding bands in micas. In addition to OH bands that refer to the smectite structure, AlOHAl and AlOHFe bands of the pyrophyllite structural fragments were identified. The band-position variation ranges overlap in a few cases (AlOHFe and MgOHMg; AlOHAl of smectite and AlOHFe of pyrophyllite-like component).

Unambiguous interpretation of the OH-stretching vibrations was found to be possible only for smectite samples with known chemical compositions, so that IR data cannot be used for quantitative determination of octahedral cation composition of mixtures of dioctahedral 2:1 phyllosilicates. In the case of the studied monomineral smectites with known chemical compositions, IR data provided information on the short-range order/disorder in the distribution of octahedral cations along cation-OH-cation directions. This information can be employed, in conjunction with the data of other spectroscopic and diffraction techniques, in the analysis of short-range octahedral cation distribution.
Role of smectites and Al-substituted goethites in the catalytic condensation of arginine and glucose
Authors: Gonzalez Javier M. , Laird David A.
Published: August 2004

The polyphenol theory of humic-substance formation has been studied extensively; however, an alternative theory, that humic substances are formed through the condensation of amino acids and reducing sugars (Maillard reaction), has not been explored to the same extent. The general objectives of this study were to determine whether smectites and goethites catalyze the abiotic polymerization of arginine and glucose to form humic-like compounds. The effects of smectite type, saturating cation, and the degree of Al substitution in goethites on the polymerization reaction were also studied. Four cation-saturated smectites and four Al-substituted goethites were incubated abiotically with solutions containing a mixture of arginine + glucose for 21 days at 37°C. After the incubations, total C recovered ranged from 80.6 to 123.8% and from 100.5 to 105.1% for the smectite and goethite systems, respectively. At the end of the incubations, 21.4–50.3% of the added C and 16.5–90% of the added N were sorbed on the various smectites, and 6.2–9.0% of the added C and 2.3–4.6% of added N was sorbed on the goethites in a form that could not be desorbed by washing with 100 mM CaCl2. X-ray diffraction analysis indicated that some of the sorbed C was intercalated in the smectites and FTIR analysis provided evidence of new absorption bands at 1650 and 1668 cm−1, which are consistent with Maillard reaction products. Thus, it is concluded that smectites catalyze the condensation of arginine and glucose to form humic-like products. Goethites, however, have little or no ability to catalyze this reaction.
Mixed-layer kaolinite-smectite minerals in a red-black soil sequence from basalt in Sardinia (Italy)
Authors: Vingiani Simona , Righi Dominique , Petit Sabine , Terribile Fabio
Published: August 2004

Clay minerals from soils of a red-black soil complex developed from basaltic parent material in Sardinia are formed along a short toposequence (200 m). At the foot of the sequence, a clay-rich, black Vertisol forms, whereas at the summit, the soil is a dark reddish-brown Inceptisol. X-ray diffraction, infrared spectroscopy (FTIR), cation exchange capacity (CEC) and permanent and variable charges analyses were used, and the data show that clay minerals varied according to soil horizon and topographic position of the soil. Clay minerals in the Inceptisol are dominated by kaolinite and mixed-layer kaolinitesmectite (K-S, K:S >0.5), whereas the Vertisol contains smectites and K-S with K:S proportions <0.5. In the Vertisol, the proportion of kaolinitic layers in the K-S increases from the C horizon (K:S ∼0.35–0.40) to the Ap horizon (K:S ∼0.40–0.45). This soil clay-mineral distribution, in relation to topography, is similar to that reported for other (kaolinitic) red-black (smectitic) soil associations in subtropical and tropical areas. The sequence forms by downward drainage on summits and slopes, and buildup of ions in ‘lows’ produces smectites. Fourier transform infrared spectra indicate that two types of smectite are formed in the C horizon of the Vertisol; one is more ferric (Fe-beidellite, nontronite), the other more aluminous. Mineralogical evolution in the soil profile (from C to Ap horizon) shows a decreasing proportion of ferric smectite layers (compared to the more aluminous smectite layers). This would indicate that ferric smectite layers are preferentially transformed (or dissolved) to give kaolinite layers, with Fe precipitating as oxides and/or oxy-hydroxides or retained partly in kaolinite layers. Because the surface properties of clay minerals are related to mineralogy, the CEC (33–41 cmol kg−1) in the brown Inceptisol is ∼50% pH-dependent charge while in the Vertisol up to ∼75% of the CEC (48–61 cmol kg−1) comes from accessible permanent charges.
Desiccants
Authors: Cohen Alan P.
Published: July 2004

Desiccants are classified by four drying mechanisms: chemical reaction, physical absorption with constant relative humidity, physical absorption with variable relative humidity, and physical adsorption. Solid desiccant materials including activated alumina, silica gel, molecular sieves, and lithium chloride are commonly used in both static and dynamic drying. Other solids such as barium oxide, calcium chloride, calcium oxide, calcium sulfate, clays, metal halides, perchlorates, phosphorus pentoxide, sodium and potassium hydroxides, are used mainly in static drying.

Desiccants must be chemically compatible with the material being dried, and, if in doubt, the compatibility should be tested prior to use. Ideally, the desiccant and the material should not react to avoid producing harmful or undesirable by‐products. The water capacity of some static desiccants and the efficiency (or effectiveness) of various desiccants in drying air and laboratory solvents vary widely. The dynamics of closed‐system drying involves the exponential decay of the water content over time.

Desiccants used in dynamic applications include both liquids and solids. Solid adsorbents are often used in drying systems with multiple beds, and sometimes in rotating wheels. The largest users of solid desiccants are the hydrocarbon processing, insulating glass drying, and packaging industries.
Hydrogen Induced Polarization–Nuclear‐Spin Hyperpolarization in Catalytic Hydrogenations without the Enrichment of Para‐ or Orthohydrogen
Authors: Jonischkeit Thorsten , Woelk Klaus
Published: August 2004

During the last 40 years, Prof. Dr. Joachim Bargon, to whom several articles in this issue are dedicated, has contributed more than 90 scientific publications to the understanding of NMR hyperpolarization phenomena such as chemically induced dynamic nuclear polarization (CIDNP) or parahydrogen induced polarization (PHIP). Both techniques are extremely useful for elucidating the mechanisms and kinetics of chemical reactions involving radicals or catalytic hydrogenations, respectively. To honor Joachim Bargon's scientific achievements, we dedicate to him an additional, newly discovered and somewhat unexpected twist to the PHIP methodology. Accordingly, NMR spectra exhibit the unique, enhanced absorption and emission patterns of PHIP not only if the hydrogen for the catalytic reactions is enriched in one of its nuclear spin states (parahydrogen or orthohydrogen) but also if it is at its thermodynamic equilibrium. Thermally equilibrated gaseous hydrogen is obtained from commercially available hydrogen gas bombs or from electrolytic hydrogen generators. The new finding is explained with the quantum mechanical properties of the small, highly symmetric hydrogen molecule.
Conformationally Restricted Arene Intermediates in the Intermolecular Heck Arylation of Vinylarenes
Authors: Hii King Kuok (Mimi) , Claridge Timothy D. W. , Giernoth Ralf , Brown John M.
Published: August 2004

The NMR observation of σ‐benzylpalladium intermediates at low temperature, formed by reaction of arylpalladium diphosphine cations with simple vinylarenes, indicates restricted rotation in the adjacent aryl ring. The stability of the intermediate is greater in the dppp than in the dppf series. By a combination of NMR techniques, it was possible to characterise the intermediate, and to consider permissible structures.
Efficient Synthesis of Tris(acetonitrile)‐(η5‐cyclopentadienyl)‐ ruthenium(II) Hexafluorophosphate via Ruthenocene
Authors: Kündig E. Peter , Monnier Florian R.
Published: August 2004

[Ru(η5‐C5H5)(CH3CN)3][PF6] (1), a versatile precursor to catalysts containing the CpRu+ complex fragment, can be obtained in high yield via Cp/naphthalene exchange in ruthenocene. This new route via the complex [RuCp(naphthalene)][PF6] (4) avoids both highly toxic thallium reagents and the need for a photoreactor.
Demographic trends and biological status of historic populations from Central Poland: The Ostrów Lednicki microregion
Authors: Budnik Alicja , Liczbińska Grażyna , Gumna Izabela
Published: July 2004

The microregion of Ostrów Lednicki in the province of Wielkopolska was the center of the formation of the Polish State in Early Middle Ages. The analysis of skeletal remains and parish records from the region documented the biological status of inhabitants and its changes over a millennium. The study material comprised 424 human skeletons from an Early Medieval burial ground on Lake Lednica, records of 2,704 deaths from the registers of the Roman Catholic parish of Dziekanowice, made between 1818–1903, data on the deaths of 929,192 inhabitants of rural areas all over the province Wielkopolska obtained from Prussian statistical materials for the years 1865–1900, and comparative data from the literature. Assuming both a stationary population model and a stable population model with nonzero natural increase, parameters of life tables and measures of opportunity for natural selection (Crow's index Im, potential gross reproductive rate Rpot, and the biological state index Ibs) were calculated for the Early Middle Ages and for the two periods of the 19th century which were characterized by different laws of land ownership and thus different rural economies. In the first period, peasants were tenants, whereas in the second, they were given freehold of the land they cultivated. Causes of death were also analyzed. A distinct increase in longevity from the early Middle Ages to the end of the 19th and the beginning of the 20th century was found. This was related to a higher level of demographic development in the parish of Dziekanowice during the 19th century, which was achieved earlier than in other areas of Poland. This was confirmed by genetic measures: coefficients of exogamy and coefficients of kinship. The reasons were related to the historical prominence of this region and to its proximity to the first two capitals of the Polish state, Gniezno and Poznań. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
New method for surname studies of ancient patrilineal population structures, and possible application to improvement of Y‐chromosome sampling
Authors: Manni Franz , Toupance Bruno , Sabbagh Audrey , Heyer Evelyne
Published: July 2004

Several studies showed that surnames are good markers to infer patrilineal genetic structures of populations, both on regional and microregional scales. As a case study, the spatial patterns of the 9,929 most common surnames of the Netherlands were analyzed by a clustering method called self‐organizing maps (SOMs). The resulting clusters grouped surnames with a similar geographic distribution and origin. The analysis was shown to be in agreement with already known features of Dutch surnames, such as 1) the geographic distribution of some well‐known locative suffixes, 2) historical census data, 3) the distribution of foreign surnames, and 4) polyphyletic surnames. Thus, these results validate the SOM clustering of surnames, and allow for the generalization of the technique. This method can be applied as a new strategy for a better Y‐chromosome sampling design in retrospective population genetics studies, since the idenfication of surnames with a defined geographic origin enables the selection of the living descendants of those families settled, centuries ago, in a given area. In other words, it becomes possible to virtually sample the population as it was when surnames started to be in use. We show that, in a given location, the descendants of those individuals who inhabited the area at the time of origin of surnames can be as low as ∼20%. This finding suggests 1) the major role played by recent migrations that are likely to have distorted or even defaced ancient genetic patterns, and 2) that standard‐designed samplings can hardly portray a reliable picture of the ancient Y‐chromosome variability of European populations. Am J Phys Anthropol 126:214–228, 2005. © 2004 Wiley‐Liss, Inc.