bluuebunny/crossref_metadata_2025 huggingface dataset:
Old groundwater influence on stream hydrochemistry and catchment response times in a small Sierra Nevada catchment: Sagehen Creek, California
Authors: Rademacher Laura K. , Clark Jordan F. , Clow David W. , Hudson G. Bryant
Published: February 2005

The relationship between the chemical and isotopic composition of groundwater and residence times was used to understand the temporal variability in stream hydrochemistry in Sagehen basin, California. On the basis of the relationship between groundwater age and [Ca2+], the mean residence time of groundwater feeding Sagehen Creek during base flow is approximately 28 years. [Cl−]:[Ca2+] ratios in Sagehen Creek can be used to distinguish between two important processes: changes in the apparent age of groundwater discharging into the creek and dilution with snowmelt. The mean residence time of groundwater discharging into the creek is approximately 15 years during snowmelt periods. The results from this study have implications for hydrograph separation studies as groundwater is not a single, well‐mixed chemical component but rather is a variable parameter that predictably depends on groundwater residence time. Most current models of catchment hydrochemistry do not account for chemical and isotopic variability found within the groundwater reservoir. In addition, this study provides valuable insight into the long‐term hydrochemical response of a catchment to perturbations as catchment‐flushing times are related to the mean residence time of water in a basin.
Nonmigrating tides in equinox temperature fields from the Extended Canadian Middle Atmosphere Model (CMAM)
Authors: Ward William E. , Fomichev Victor I. , Beagley Stephen
Published: February 2005

The extended Canadian Middle Atmosphere model has been analyzed for wave 0, 1 and wave 2 temperature signatures associated with diurnal and semidiurnal migrating and nonmigrating tides. These waves are ubiquitous in the model data and have significant amplitudes relative to the migrating diurnal tide. They are formed both by forcing in the troposphere and through nonlinear interaction in the middle atmosphere. Superposition of the tidal signatures results in significant longitudinal variations in the local derived diurnal and semidiurnal amplitudes and localized regions of convective instability which may be a source for the inversion layers observed in the mesosphere and the bores seen in airglow data. It is conjectured that the dissipation of tidal components can only be understood when they are considered as a system and not as individual components. The superposed tidal fields have a strong geographic dependence. Associated airglow signatures and chemistry will exhibit similar variability.
Volcanic spreading of Vesuvius, a new paradigm for interpreting its volcanic activity
Authors: Borgia A. , Tizzani P. , Solaro G. , Manzo M. , Casu F. , Luongo G. , Pepe A. , Berardino P. , Fornaro G. , Sansosti E. , Ricciardi G. P. , Fusi N. , Di Donna G. , Lanari R.
Published: February 2005

We integrate geologic, structural, leveling and Differential SAR Interferometry data to show that Vesuvius began to spread onto its sedimentary substratum about 3,600 years ago. Moreover, we model the detected deformation with a solution of the lubrication approximation of the Navier‐Stokes equations to show that spreading may continue for about 7,200 years more. Correlation of volcanic spreading with phases of the eruptive activity suggests that Plinian eruptions, which are thought to pose the major hazard, are less likely to occur in the near future.
On the preferential occurrence of interplanetary shocks in July and November: Causes (solar wind annual dependence) and consequences (intense magnetic storms)
Authors: Echer E. , Gonzalez W. D. , Tsurutani B. T. , Vieira L. E. A. , Alves M. V. , Gonzalez A. L. C.
Published: February 2005

An annual dependence of interplanetary shock rate near 1 AU was found with preferential shock occurrence in July and in November. Although a solar origin for this dependence can not be discarded, it is shown that at least part of this shock distribution can be explained or caused by the annual dependence of solar wind parameters. Such annual dependence in plasma and magnetic field parameters makes the shock formation easier, in the second half year, due to the lower average solar wind bulk and characteristic speeds (Alfvenic and magnetosonic). These asymmetric interplanetary space propagation conditions are probably due to the Earth being exposed to solar wind from different solar magnetic hemispheres in both half years. Furthermore, the peaks in shock distribution are coincident with the peaks in the very intense geomagnetic storms distribution found by Clúa de Gonzalez et al. [2001]. It is suggested that the irregularity in geomagnetic activity is associated with the shock rate annual dependence. These results might imply that solar wind emitted from the opposite solar magnetic hemispheres has slightly different properties.
Influence of protons on Fe‐Mg interdiffusion in olivine
Authors: Hier‐Majumder S. , Anderson I. M. , Kohlstedt D. L.
Published: February 2005

We report the experimental measurement of Fe‐Mg interdiffusivity in olivine along the [001] crystallographic direction in a water‐saturated environment at pressures of 0.1 to 6 GPa and temperatures between 1373 and 1450 K. The concentration of water‐derived protons in olivine was controlled by varying the water fugacity. The oxygen fugacity was set by the Ni‐NiO solid state reaction, while the activity of silica was controlled by the presence of orthopyroxene. In this work, we report diffusivity as a function of temperature, pressure, and water fugacity following the relation Fe–Mg = exp [−(Q + PV*)/RT] m2s−1, where log(Do) = (−14.8 ± 2.7), r = 0.9 ± 0.3, Q = 220 ± 60 kJ/mol, and V* = (16 ± 6) × 10−6m3/mol. The approximately linear increase in diffusivity with increasing water fugacity is consistent with incorporation of protons associated with octahedral cation vacancies to form defect complexes. Our results indicate that cation diffusion in water‐saturated olivine is ∼50 times faster than under water‐absent conditions at a pressure of 5 GPa and a temperature of 1373 K.
Internal waves and undular bores in mesospheric inversion layers
Authors: Seyler C. E.
Published: February 2005

The linear theory of internal gravity waves and the nonlinear development of undular bores supported by mesospheric thermal inversion layers is presented. Whenever the buoyancy frequency has a local maximum as a result of a local increase in the potential temperature gradient, internal waves having a frequency between the maximum and minimum values of the buoyancy frequency can exist. Two‐dimensional nonlinear solutions of a simplified model show that long‐wavelength initial disturbances of finite amplitude, nonlinearly steepen, and form undulatory bores and that the analysis and numerical solutions presented show that mesospheric bores are consistent with nonlinear internal gravity waves trapped within a thermal inversion layer. The implications of linear theory and numerical solutions to the observations of mesospheric bores are discussed. In particular, the simulations agree with the observed separation of wave crests, which is in consistent with the notion that a mesospheric bore is composed of a train of solitary waves each with an amplitude‐dependent speed.
Use of dissolved and vapor‐phase gases to investigate methanogenic degradation of petroleum hydrocarbon contamination in the subsurface
Authors: Amos Richard T. , Mayer K. Ulrich , Bekins Barbara A. , Delin Geoffrey N. , Williams Randi L.
Published: February 2005

At many sites contaminated with petroleum hydrocarbons, methanogenesis is a significant degradation pathway. Techniques to estimate CH4 production, consumption, and transport processes are needed to understand the geochemical system, provide a complete carbon mass balance, and quantify the hydrocarbon degradation rate. Dissolved and vapor‐phase gas data collected at a petroleum hydrocarbon contaminated site near Bemidji, Minnesota, demonstrate that naturally occurring nonreactive or relatively inert gases such as Ar and N2 can be effectively used to better understand and quantify physical and chemical processes related to methanogenic activity in the subsurface. In the vadose zone, regions of Ar and N2 depletion and enrichment are indicative of methanogenic and methanotrophic zones, and concentration gradients between the regions suggest that reaction‐induced advection can be an important gas transport process. In the saturated zone, dissolved Ar and N2 concentrations are used to quantify degassing driven by methanogenesis and also suggest that attenuation of methane along the flow path, into the downgradient aquifer, is largely controlled by physical processes. Slight but discernable preferential depletion of N2 over Ar, in both the saturated and unsaturated zones near the free‐phase oil, suggests reactivity of N2 and is consistent with other evidence indicating that nitrogen fixation by microbial activity is taking place at this site.
Neurogenic double‐peaked vasoconstriction of human gastroepiploic artery is mediated by both α1‐ and α2‐adrenoceptors
Authors: Fukui Daisuke , Yang Xiao‐Ping , Chiba Shigetoshi
Published: February 2005

The contribution of postjunctional P2X receptors and subtypes of α‐adrenoceptors to vasoconstrictor responses following periarterial electrical nerve stimulation (PNS, 30 s trains of pulses at a frequency of 2, 4 or 8 Hz) was investigated in human gastroepiploic arteries.

The vasoconstrictor response to PNS at a stimulation of 4 or 8 Hz was a two‐peaked response, whereas at a frequency of 2 Hz it appeared only as a late peak. All vasoconstrictions evoked by PNS were abolished by phentolamine, a nonselective α‐adrenoceptor inhibitor, but not by α,β‐methylene ATP, a P2X receptor‐desensitizing agent.

The early peak to PNS at 4 or 8 Hz was abolished by prazosin, an α1‐adrenoceptor antagonist, while the late one still remained, although it was markedly inhibited. The responses remaining after prazosin were blocked by rauwolscine. The vasoconstrictor response to PNS at 2 Hz was not affected by prazosin (0.1 μM), but was abolished by rauwolscine (0.1 μM), an α2‐adrenoceptor antagonist.

OPC‐28326(10 μM), a newly developed vasodilator, which preferentially exerts its antagonistic actions on the α2B‐ and α2C‐adrenoceptors, significantly reduced the noradrenaline‐induced vasoconstriction in the absence or presence of prazosin. OPC‐28326 had a greater inhibitory effect on the late peak evoked by PNS than the early one. The neurogenic responses remaining after OPC‐28326 were abolished by prazosin.

The present results suggest that sympathetic vasoconstriction of the human gastroepiploic artery is mediated by both α1‐ and α2‐adrenoceptors postjunctionally, but not by P2X receptors. The α2‐adrenoceptors may be preferentially activated at a low frequency of stimulation, which induces a constriction more slowly than that by α1‐adrenoceptors. The existence of α2‐adrenoceptors may cause an enhancement of α1‐adrenoceptor‐induced responses.

British Journal of Pharmacology (2005) 144, 737–742. doi:10.1038/sj.bjp.0705975
Cardioprotective effect of an endothelin receptor antagonist during ischaemia/reperfusion in the severely atherosclerotic mouse heart
Authors: Gonon Adrian T , Bulhak Alexander , Bröijersén Anders , Pernow John
Published: February 2005

Endothelin (ET) receptor antagonists are cardioprotective during myocardial ischaemia and reperfusion through a nitric oxide (NO)‐dependent mechanism. The aim of the present study was to investigate whether the ET receptor antagonist, bosentan, is cardioprotective in atherosclerotic mice.

Buffer‐perfused hearts from apolipoprotein E/LDL receptor double knockout (KO) and wild‐type (WT) mice were subjected to global ischaemia and reperfusion.

Following reperfusion, the recovery of rate–pressure product (RPP; left ventricular developed pressure (LVDP) × heart rate) was equally impaired in WT and KO mice given vehicle (34±8 and 29±9%, respectively). The ETA/ETB receptor antagonist bosentan (10 μmol l−1) improved recoveries to 57±10% in WT and to 68±10% in KO mice (P<0.01). Similar effects were observed for the recovery of left ventricular end‐diastolic pressure (LVEDP), developed pressure and dP/dt.

Bosentan improved the recovery of coronary flow in both KO and WT mice. Recovery of coronary flow was significantly higher in the KO mice given bosentan (135±15%) than in the WT group (111±12%; P<0.01). ET‐1 (1 nmol l−1) impaired recovery of coronary flow in both WT and KO mice though this effect was more pronounced in the KO mice (P<0.01).

Coronary outflow of NO during reperfusion was enhanced in both KO and WT mice following bosentan administration.

The ETA/ETB receptor antagonist bosentan protects the atherosclerotic mouse heart from ischaemia/reperfusion injury. The observation that ET receptor blockade and stimulation have a greater effect on coronary flow in atherosclerotic hearts indicates an increased activation of the ET system in atherosclerotic coronary arteries.

British Journal of Pharmacology (2005) 144, 860–866. doi:10.1038/sj.bjp.0706117
Enhanced vascular reactivity of small mesenteric arteries from diabetic mice is associated with enhanced oxidative stress and cyclooxygenase products
Authors: Pannirselvam Malarvannan , Wiehler William B , Anderson Todd , Triggle Chris R
Published: February 2005

Vascular reactivity to the alpha‐adrenoceptor agonist phenylephrine (PE) was enhanced in small mesenteric arteries (SMA) from diabetic (db/db) mice under both high and low in vitro oxygen conditions.

Mechanical removal of the endothelium significantly attenuated the enhanced vascular reactivity of SMA from db/db mice.

Acute incubation of the SMA with sepiapterin, a precursor of tetrahydrobiopterin, and Nω‐nitro L‐arginine (L‐NA), an inhibitor of nitric oxide (NO) synthase (NOS), resulted in no significant change in the enhanced vascular reactivity to PE in db/db mice. Endothelial nitric oxide synthase (eNOS) mRNA and protein levels in SMA were not different between db/+ and db/db mice.

Acute incubation of SMA with a combination of polyethylene glycol superoxide dismutase and catalase significantly reduced the enhanced contraction to PE in db/db mice. There were higher levels of malondialdehyde, a marker of lipid peroxidation and basal superoxide as measured by dihydroethidium staining, in SMA from db/db mice compared to db/+ mice.

Acute incubation with indomethacin, a nonselective inhibitor of cyclooxygenase, SQ 29548, a selective thromboxane receptor antagonist and furegrelate, a thromboxane synthesis inhibitor, significantly attenuated the enhanced contraction to PE in SMA from db/db mice.

This study demonstrates that the enhanced contractility of SMA from db/db mice to PE was endothelium dependent and involves elevated reactive oxygen species, cyclooxygenase activity and thromboxane synthesis, but not changes in the eNOS/NO pathway.

British Journal of Pharmacology (2005) 144, 953–960. doi:10.1038/sj.bjp.0706121
Prenatal cocaine exposure increases apoptosis of neonatal rat heart and heart susceptibility to ischemia–reperfusion injury in 1‐month‐old rat
Authors: Bae Soochan , Zhang Lubo
Published: February 2005

Maternal cocaine administration during pregnancy increased apoptosis in near‐term fetal rat heart. The present study tested the hypothesis that prenatal cocaine exposure increases the heart susceptibility to ischemia/reperfusion injury in the offspring.

Pregnant Sprague–Dawley rats received cocaine (30 mg kg−1 day−1) or saline from days 15 to 21 of gestational age. Maternal body weights were not significantly different at the end of cocaine treatment, but body weights of offspring were decreased slightly at ages of 1, 3, and 7 days. Although heart‐to‐body weight ratio was not affected at all ages examined, prenatal cocaine significantly increased left ventricular myocyte size at an age of 30 days.

Additionally, prenatal cocaine increased DNA fragmentation measured in the hearts isolated from offspring of 1, 3, 7, and 21 days, but not of 30 days, with the peak at 3‐day neonates. Antiapoptotic (Bcl‐2 and Bcl‐XL) and proapoptotic (Bax and Bad) proteins were expressed in neonatal rat hearts of both groups. Prenatal cocaine exposure decreased levels of Bcl‐2 in 21‐day and increased Bax in 21‐ and 30‐day rat hearts.

In addition, hearts of 30‐day‐old male progeny were studied using the Langendorff preparation, and were subjected to 25 min of ischemia and 60 min of reperfusion. Preischemic baseline values of left ventricular (LV) function were the same between the two groups. However, prenatal cocaine exposure significantly attenuated postischemic recovery of LV function, and significantly increased elevated LV end diastolic pressure during reperfusion. This was associated with a significant increase in ischemia/reperfusion‐induced LV myocardial infarct size.

The results suggest that prenatal cocaine exposure induces abnormal apoptosis and myocyte hypertrophy in postnatal heart, leading to an increased heart susceptibility to ischemic insults in postnatal life.

British Journal of Pharmacology (2005) 144, 900–907. doi:10.1038/sj.bjp.0706129
Dynamics of layered Jahn–Teller crystals of rare-earth compounds (Review)
Authors: Kut’ko V. I.
Published: February 2005

Spectroscopic data on crystals of rare-earth compounds having structural instability due to the cooperative Jahn–Teller effect are reviewed. Based on an analysis of these data, it is inferred that the dynamic coupling of low-frequency electronic excitations of the rare-earth ions with crystal lattice vibrations plays an essential role in the formation of the low-energy spectra of layered crystals. The role of this coupling in the formation of anomalies of various physical properties of crystals of rare-earth compounds with highly anisotropic structure is examined.
Kinetic properties and magnetic susceptibility of Pr0.67Ca0.33MnO3 under hydrostatic pressure
Authors: Itskevich E. S. , Kraidenov V. F. , Petrova E. A.
Published: February 2005

Measurements of the magnetic susceptibility χ, thermopower α, and resistivity ρ of the manganate Pr1−xCaxMnO3 with x=0.33 are made on single-crystal samples in the temperature range 77–300 K and at pressures up to P=13 kbar. At P⩾8.8 kbar a metal-insulator transition is observed. The phase transition temperatures and their pressure dependence are obtained: the temperature of a possible structural transition Tn≈250 K (∂Tn/∂P=−1.7 K/kbar); the charge-ordering temperature Tco≈230 K (∂Tco/∂P=−0.8 K/kbar); the Néel temperature TN≈140 K (∂TN/∂P=−1.1 K/kbar); the temperature of the appearance of a spontaneous ferromagnetic moment TC≈100 K (∂TC/∂P=−1.2 K/kbar), and the temperature of the metal-insulator transition TMI (∂TMI/∂P=2.8 K/kbar). The α(T) curve is dome-shaped and is shifted into the negative region with increasing pressure, twice changing sign with the variation of the temperature. As TC is approached the thermopower α<0, with |α|>500 μV/K.
Temperature anomalies of the resistivity and thermopower of polycrystalline copper subjected to plastic deformation
Authors: Dmitriev V. M. , Prentslau N. N. , Svetlov V. N. , Stepanov V. B.
Published: February 2005

The results of an experimental study of the resistivity ρ and thermopower in the temperature range 4.2–300 K are presented for commercial-grade copper subjected to plastic deformation at room temperature. A number of inter-correlated anomalies, due to dislocations, are observed in the temperature dependence of the resistivity and thermopower. The probable cause of these anomalies is the resonance scattering of free electrons and thermal phonons by electrons localized near the dislocations.
Co-Opting Voluntarism? Exploring the Implications of Long-Term Care Reform for the Nonprofit Sector in Ontario
Authors: Skinner Mark W , Rosenberg Mark W
Published: February 2005

Within public policy discourse on health care restructuring and voluntarism, the nonprofit sector is now expected to play an active and direct role in the provision of health care services. The viability of the nonprofit sector to take up this role, however, remains unclear. This paper explores the changing role of nonprofit organisations with respect to the provision of long-term care in Ontario, Canada, where extensive restructuring of public services occurred during the 1990s. Drawing on a critical review of legislation, government policies and documents, and stakeholder reports, the authors present a comparative study of two distinct long-term care reform models, featuring public and private provision, respectively, which were developed by ideologically opposed provincial governments. The results indicate that despite unanimous promotion of voluntarism (and the attendant ascendancy of the nonprofit sector) as a central feature of health care restructuring, the divergent reform models actually trap nonprofit organisations between direct incorporation within public provision on the one hand, and direct free-market competition on the other. The findings suggest that underscoring long-term care reform in Ontario, and elsewhere, is the co-option of the nonprofit sector, which resonates with concern for its ability to replace effectively the public provision of health care services. The results also point to the need to conceptualise the consequent actions taken by nonprofit organisations in order to inform current debates surrounding health care restructuring and voluntarism.
Individual Determinants of Participation in Community Development in Indonesia
Authors: Beard Victoria A
Published: February 2005

Given the new decentralization legislation in Indonesia, citizen participation is an increasingly important factor in planning and development policies. Yet policymakers have inadequate information about the types of individuals likely to contribute their knowledge, time, and economic resources to the development process. This paper provides a background and conceptual framework for understanding citizen participation in community development as well as the related components of civil society and social capital in Indonesia. A series of logistic and ordinary least squares regression models are used to analyze the effect of individual demographic and socioeconomic characteristics on the likelihood of participation in community development. I conclude that participatory community development (1) restricts women's participation beyond the role of family caretaker, and (2) has a limited capacity to help the poor.
Multiple Visioning: New Ways of Constructing Transnational Spatial Visions
Authors: Zonneveld Wil
Published: February 2005

In many parts of Europe, but also at the level of the European Union and the much higher level of the Council of Europe, the creation of spatial visions is now underway. However, these spatial visions often lack an essential ingredient of spatial planning, namely maps. This omission may seem paradoxical, because maps are essential for communicating ideas with a spatial dimension. The vast spatial and political complexities at transnational and European levels are addressed by elementary processes of visioning and mapmaking. Because maps are social constructs, no single, optimal map will exist. Transnational visioning therefore implies the creation of multiple maps and multiple visions.
Variation for seed coat and pod wall percentage and other traits in a germplasm collection and historical cultivars of lupins
Authors: Clements J. C. , Dracup M. , Buirchell B. J. , Smith C. G.
Published: February 2005

Accessions totalling 1425 from the Australian Lupin Collection representing 9 Old World lupin species and Lupinus mutabilis Sweet, a New World species, were sampled for seed coat and pod wall percentage, seed weight, and number of seeds per pod. These traits are of importance to the breeding objective of lowering seed coat and pod wall proportions in crop lupins. Seed coat percentage mean values among the species ranged from 12.7 in L. mutabilis to 33.7 in L. pilosus L. The 4 species that have been subject to selection (L. mutabilis, L. albus L., L. angustifolius L., and L. luteus L.) had lower mean seed coat percentages than the other species with little domestication. The rough-seeded lupin species had higher seed coat percentages relative to the smooth-seeded species except for L. micranthus Guss., which had 31.5% seed coat and small seeds. Within L. angustifolius there was no difference between the mean seed coat percentage values for wild v. domesticated or hard v. soft-seeded entries, although wild accessions of L. angustifolius tended to have lower seed weight, higher pod wall percentage, and more seeds per pod than domesticated accessions. There was no correlation in L. angustifolius germplasm between seed coat percentage and pod wall percentage, indicating that selection for one will not influence the other character. Accessions with the lowest seed coat percentage were from Turkey, Greece, and Cyprus, and those with the lowest average pod wall percentage were from Spain and Cyprus. Mean pod wall percentages ranged from 30.9 in L. albus to 57.1 in L. micranthus; figures that are high compared with other legumes. Large ranges in seed weight were found particularly in L. albus, L. pilosus, and L. angustifolius.
In addition to the germplasm collection, 21 Australian cultivars, released from 1967 to 1999, were evaluated at one site over 2 years for the same traits. There was a negative correlation between seed coat percentage and seed weight for both L. angustifolius historical cultivars and germplasm, indicating that further reductions in seed coat percentage could be achieved by crossing large seeded types with low seed coat types. Pod wall percentage was negatively correlated with both year of release and yield, and positively correlated with days to flowering. These data support other findings that breeding for the reduction of pod wall can lead to yield improvements. The germplasm collection assessed here provides lines with lower seed coat and pod wall compared with what is available in breeding lines or cultivars.
Disease resistance genes in a doubled haploid population of two-rowed barley segregating for malting quality attributes
Authors: Emebiri L. C. , Platz G. , Moody D. B.
Published: February 2005

Malting barley (Hordeum vulgare L.) improvement involves selection for many quality traits, but the search for and deployment of resistance genes has continued to be an equally important endeavour. As an aid to phenotypic selection in breeding programs, gene mapping can serve to characterise genes known to exist in elite breeding lines. In the present study, 180 doubled haploid lines derived from the cross of VB9524/ND11231*12 were screened for disease resistance under field and greenhouse conditions. Quantitative trait locus (QTL) mapping and classical genetic linkage approaches were used to identify and map QTLs for resistance to powdery mildew (Blumeria graminis f.sp. hordei), net form of net blotch (Pyrenophora teres f. teres) and stem rust (Puccinia graminis f.sp. tritici). The analyses offered a comparison between QTL mapping and traditional genetic linkage analysis. Both approaches identified a QTL for powdery mildew resistance on chromosome 1H, which mapped to the approximate genomic location of the Mla6 gene. Similarly, both methods identified a major QTL for resistance to net form of net blotch on chromosome 6H and for stem rust resistance on chromosome 7H. The QTL for stem rust resistance on 7H mapped to the approximate location of the Rpg1 gene. Classical linkage analysis identified the 3 QTLs with major effects, but was unable to detect 3 other loci with minor effects.
Yield loss and fungicide control of stem rust of wheat
Authors: Loughman R. , Jayasena K. , Majewski J.
Published: February 2005

Yield loss in wheat from natural infections with Puccinia graminis f.sp. tritici ranged from 10 to 45% in 3 experiments over 2 years. Fungicide reduced subsequent stem rust severity on plant parts that were only slightly infected at the time of fungicide application, but was not effective on plant parts that were more heavily infected when treated. Fungicide control of stem rust was economic in a range of situations. Fungicide applied at head emergence with low disease incidence (5% of stems) increased yield by 0.3 t/ha. When applied prior to head emergence with high disease incidence at low disease severity, yield increased by 0.8–1.5 t/ha, depending on duration of control. At a high disease incidence and moderate disease severity, yield increases of 0.4–0.6 t/ha were observed. Grain quality was also significantly improved with fungicide. Fungicide was more effective when applied immediately following detection compared with a 3-week delay. Folicur was more effective at reducing disease and increasing yield or quality than Impact or Triad.
Seed yield, oil content, and fatty acid composition of stock (Matthiola incana) under saline irrigation
Authors: Heuer Bruria , Ravina Israela , Davidov Sara
Published: February 2005

The influence of irrigation with saline water on the seed yield, oil content, and quality of stock (Matthiola incana), an oilseed plant rich in omega-3, was studied under greenhouse and field conditions as part of a study to assess the potential of stock to replace low cash field crops in areas of marginal water use due to water scarcity. Water of electrical conductivity ≤6 dS/m did not have a negative effect on yield parameters. Total yield, seed number, and oil content were not affected by salinity, whereas the content of omega-3 was significantly increased.
Aggregation promoting C-terminal truncation of α-synuclein is a normal cellular process and is enhanced by the familial Parkinson's disease-linked mutations
Authors: Li Wenxue , West Neva , Colla Emanuela , Pletnikova Olga , Troncoso Juan C. , Marsh Laura , Dawson Ted M. , Jäkälä Pekka , Hartmann Tobias , Price Donald L. , Lee Michael K.
Published: February 2005

Abnormal biology of α-synuclein (α-Syn) is directly implicated in the pathogenesis of Parkinson's disease and other α-synucleinopathies. Herein, we demonstrate that C-terminally truncated α-Syn (α-SynΔC), enriched in the pathological α-Syn aggregates, is normally generated from full-length α-Syn independent of α-Syn aggregation in brains and in cultured cells. The accumulation of α-SynΔC is enhanced in neuronal cells as compared with nonneuronal cells. Significantly, the expression of familial Parkinson's disease-linked mutant α-Syn is associated with the enhanced cellular accumulation of α-SynΔC. Moreover, substoichiometric amounts of α-SynΔC enhance thein vitroaggregation of the more abundant full-length α-Syn. Finally, cases of α-synucleinopathy exhibit increases in the total soluble α-Syn and a higher proportion of soluble α-SynΔC, a condition favoring the aggregation of α-Syn. Collectively, our results indicate that the biology behind the generation and accumulation of α-SynΔC is likely to have relevance for the initiation and the progression of α-Syn aggregationin vivo.
The role of latitude in mobilism debates
Authors: Irving Edward
Published: February 2005

In the early 1920s, the continental displacement theory of Wegener, latitude studies of Köppen and Wegener, and Argand's ideas on mountain building led to the first mobilistic paleogeography. In the 1930s and 1940s, many factors caused its general abandonment. Mobilism was revived in the 1950s and 1960s by measurements of long-term displacement of crustal blocks relative to each other (tectonic displacement) and to Earth's geographic pole (latitudinal displacement). Also, short-term or current displacements can now be measured. I briefly outline the categories of tectonic and current displacement and focus on latitudinal displacement. Integration of tectonic and latitudinal displacement in the early 1970s completed the new mobilistic paleogeography, in which the transformation of rock magnetization directions into paleopoles and latitudes and the finite rotation of spherical plates about pivot points play complementary roles; this new synthesis now provides a quantitative basis for studying long-term evolution of Earth's surface features and climate, the changing environments in which life evolves.
De novodesign of an IL-4 antagonist and its structure at 1.9 Å
Authors: LaPorte Sherry L. , Forsyth Charles M. , Cunningham Brian C. , Miercke Larry J. , Akhavan David , Stroud Robert M.
Published: February 2005

An IL-4 antagonist was designed based on structural and biochemical analysis of unbound IL-4 and IL-4 in complex with its high-affinity receptor (IL-4Rα). Our design strategy sought to capture a protein–protein interaction targeting the high affinity that IL-4 has for IL-4Rα. This strategy has impact due to the potential relevance of IL-4Rα as a drug target in the treatment of asthma. To mimic the IL-4 binding surface, critical side chains for receptor binding were identified, and these side chains were transplanted onto a previously characterized,de novo-designed four-helix protein called designed helical protein 1 (DHP-1). This first-generation design resolved the ambiguity previously described for the connectivity between helices in DHP-1 and resulted in a protein capable of binding to IL-4Rα. The second-generation antagonist was based upon further molecular modeling, and it succeeded in binding IL-4Rα better than the first-generation. This protein, termed DHP-14-AB, yielded a protein with a cooperative unfolding transition (\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \setlength{\oddsidemargin}{-69pt} \begin{document} \begin{equation*}{\Delta}{\mathrm{G}}_{{\mathrm{u}}}^{0}=8.1{\;}{\mathrm{kcal}}/{\mathrm{mol}}\end{equation*}\end{document}) and an IC50of 27 μM when in competition with IL-4 whereas DHP-1 had no affinity for IL-4Rα. The crystal structure of DHP-14-AB was determined to 1.9-Å resolution and was compared with IL-4. This comparison revealed how design strategies targeting protein–protein interactions require high-resolution 3D data and the incorporation of orientation-specific information at the level of side-chains and secondary structure element interactions.
Global profiling of
Shewanella oneidensis
MR-1: Expression of hypothetical genes and improved functional annotations
Authors: Kolker Eugene , Picone Alex F. , Galperin Michael Y. , Romine Margaret F. , Higdon Roger , Makarova Kira S. , Kolker Natali , Anderson Gordon A. , Qiu Xiaoyun , Auberry Kenneth J. , Babnigg Gyorgy , Beliaev Alex S. , Edlefsen Paul , Elias Dwayne A. , Gorby Yuri A. , Holzman Ted , Klappenbach Joel A. , Konstantinidis Konstantinos T. , Land Miriam L. , Lipton Mary S. , McCue Lee-Ann , Monroe Matthew , Pasa-Tolic Ljiljana , Pinchuk Grigoriy , Purvine Samuel , Serres Margrethe H. , Tsapin Sasha , Zakrajsek Brian A. , Zhu Wenhong , Zhou Jizhong , Larimer Frank W. , Lawrence Charles E. , Riley Monica , Collart Frank R. , Yates John R. , Smith Richard D. , Giometti Carol S. , Nealson Kenneth H. , Fredrickson James K. , Tiedje James M.
Published: February 2005

The γ-proteobacterium
Shewanella oneidensis
strain MR-1 is a metabolically versatile organism that can reduce a wide range of organic compounds, metal ions, and radionuclides. Similar to most other sequenced organisms, ≈40% of the predicted ORFs in the
S. oneidensis
genome were annotated as uncharacterized “hypothetical” genes. We implemented an integrative approach by using experimental and computational analyses to provide more detailed insight into gene function. Global expression profiles were determined for cells after UV irradiation and under aerobic and suboxic growth conditions. Transcriptomic and proteomic analyses confidently identified 538 hypothetical genes as expressed in
S. oneidensis
cells both as mRNAs and proteins (33% of all predicted hypothetical proteins). Publicly available analysis tools and databases and the expression data were applied to improve the annotation of these genes. The annotation results were scored by using a seven-category schema that ranked both confidence and precision of the functional assignment. We were able to identify homologs for nearly all of these hypothetical proteins (97%), but could confidently assign exact biochemical functions for only 16 proteins (category 1; 3%). Altogether, computational and experimental evidence provided functional assignments or insights for 240 more genes (categories 2–5; 45%). These functional annotations advance our understanding of genes involved in vital cellular processes, including energy conversion, ion transport, secondary metabolism, and signal transduction. We propose that this integrative approach offers a valuable means to undertake the enormous challenge of characterizing the rapidly growing number of hypothetical proteins with each newly sequenced genome.
Ricinosomes and endosperm transfer cell structure in programmed cell death of the nucellus during
Ricinus
seed development
Authors: Greenwood John S. , Helm Michael , Gietl Christine
Published: February 2005

The ricinosome (precursor protease vesicle) is an organelle found exclusively in plant cells. Ricinosomes contain a 45-kDa pro-cysteine endopeptidase (CysEP) with a C-terminal KDEL endoplasmic reticulum retention signal. CysEP is a member of a unique group of papain-type cysteine peptidases found specifically in senescing and ricinosome-containing tissues. During seed development in the castor oil plant (
Ricinus communis
L.), the cells of the nucellus are killed as the major seed storage organ, the cellular endosperm, expands and begins to accumulate reserves. The destruction of the maternal seed tissues is a developmentally programmed cell death. Terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling revealed that nuclear DNA fragmentation occurs in the nucellar cells adjacent to the expanding endosperm. These cells exhibit ultrastructural features consistent with programmed cell death, including vesiculation of the cytosol, development of irregularly shaped nuclei, vacuolar collapse, and shrinkage of the cytoplasm. Ricinosomes containing the CysEP were identified in the nucellar cells by light and electron microscopy and immunocytochemistry. Both proCysEP and mature CysEP are present in protein extracts of the nucellar tissues during seed development. Upon collapse of the nucellar cells, the content of the ricinosomes is released into the cytoplasm, where the activated CysEP digests the remaining proteinaceous cellular debris. Digestion products of the nucellar cells are presumed taken up by the outermost cells of the endosperm, which have labyrinthine ingrowths of the outer walls typical of transfer cells.
Mesenteric B cells centrally inhibit CD4+T cell colitis through interaction with regulatory T cell subsets
Authors: Wei Bo , Velazquez Peter , Turovskaya Olga , Spricher Karsten , Aranda Richard , Kronenberg Mitchell , Birnbaumer Lutz , Braun Jonathan
Published: February 2005

Inflammatory bowel disease reflects an aberrant mucosal CD4+T cell response to commensal enteric bacteria. In addition to regulatory T cell subsets, recent studies have revealed a protective role of B cells in murine CD4+T cell colitis, but the relationship of their action to T cell immunoregulation is unknown. Here we report that mesenteric lymph node (MLN) B cells protect mice from colitis induced by Gαi2–/–CD4+T cells. Protection required the transfer of both B cells and CD8α+T cells; neither cell type alone was sufficient to inhibit CD4+T cell-mediated colitis. Similar results were also observed in colitis induced by CD4+CD45RBhiT cells. Immunoregulation was associated with localization of B cells and expansion of CD4–CD8–CD3+NK1.1+T cells in the secondary lymphoid compartment, as well as expansion of CD4+CD8α+T cells in the intestinal intraepithelial compartment. MLN B cells from Gαi2–/–mice were deficient in a phenotypic subset and failed to provide cotransfer colitis protection. These findings indicate that protective action of B cells is a selective trait of MLN B cells acquired through a Gαi2-dependent developmental process and link B cells with the formation of regulatory T cells associated with mucosal immune homeostasis.
NFATc2 and T-bet contribute to T-helper-cell-subset-specific regulation of IL-21 expression
Authors: Mehta Devangi S. , Wurster Andrea L. , Weinmann Amy S. , Grusby Michael J.
Published: February 2005

T helper (Th) 2 cells selectively express IL-21 in addition to the classic Th2 cytokines IL-4, IL-5, and IL-13. In contrast to these clustered Th2 cell cytokine genes, the IL-21 gene resides on a different chromosome and is not coordinately regulated by the same locus control region that directs the expression of other Th2 cytokines. We demonstrate that the proximal promoter of IL-21 controls its Th-cell-subset-specific expression through the action of NFATc2 and T-bet. Whereas NFATc2 directly binds to and activates transcription of the IL-21 promoter in Th2 cells, T-bet represses IL-21 transcription by inhibiting the binding of NFATc2 to the promoter in Th1 cells. These data suggest that there are multiple mechanisms by which Th-cell-subset-specific cytokine genes are regulated.
Parkin-deficient mice are not a robust model of parkinsonism
Authors: Perez Francisco A. , Palmiter Richard D.
Published: February 2005

Mutations in the human
parkin
gene cause autosomal recessive juvenile parkinsonism, a heritable form of Parkinson's disease (PD). To determine whether mutations in the mouse
parkin
gene (
Park2
) also result in a parkinsonian phenotype, we generated mice with a targeted deletion of
parkin
exon 2. Using an extensive behavioral screen, we evaluated neurological function, motor ability, emotionality, learning, and memory in aged Parkin-deficient mice. The behavioral profile of Parkin-deficient mice on a B6;129S4 genetic background was strikingly similar to that of control mice, and most differences were not reproducible by using coisogenic mice on a 129S4 genetic background. Moreover, catecholamine levels in the striatum, olfactory bulb, and spinal cord of Parkin-deficient mice were normal. In contrast to previous studies using independently generated Parkin-deficient mice, we found no evidence for nigrostriatal, cognitive, or noradrenergic dysfunction. Understanding why Parkin-deficient mice do not exhibit robust signs of parkinsonism could advance knowledge and treatment of PD.
Effects of cholinergic deafferentation of the rhinal cortex on visual recognition memory in monkeys
Authors: Turchi Janita , Saunders Richard C. , Mishkin Mortimer
Published: February 2005

Excitotoxic lesion studies have confirmed that the rhinal cortex is essential for visual recognition ability in monkeys. To evaluate the mnemonic role of cholinergic inputs to this cortical region, we compared the visual recognition performance of monkeys given rhinal cortex infusions of a selective cholinergic immunotoxin, ME20.4-SAP, with the performance of monkeys given control infusions into this same tissue. The immunotoxin, which leads to selective cholinergic deafferentation of the infused cortex, yielded recognition deficits of the same magnitude as those produced by excitotoxic lesions of this region, providing the most direct demonstration to date that cholinergic activation of the rhinal cortex is essential for storing the representations of new visual stimuli and thereby enabling their later recognition.
Serine racemase: Activation by glutamate neurotransmission via glutamate receptor interacting protein and mediation of neuronal migration
Authors: Kim Paul M. , Aizawa Hiroyuki , Kim Peter S. , Huang Alex S. , Wickramasinghe Sasrutha R. , Kashani Amir H. , Barrow Roxanne K. , Huganir Richard L. , Ghosh Anirvan , Snyder Solomon H.
Published: February 2005

Serine racemase (SR), localized to astrocytic glia that ensheathe synapses, converts
l
-serine to
d
-serine, an endogenous ligand of the NMDA receptor. We report the activation of SR by glutamate neurotransmission involving α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid receptors via glutamate receptor interacting protein (GRIP) and the physiologic regulation of cerebellar granule cell migration by SR. GRIP physiologically binds SR, augmenting SR activity and
d
-serine release. GRIP infection of neonatal mouse cerebellum
in vivo
enhances granule cell migration. Selective degradation of
d
-serine by
d
-amino acid oxidase and pharmacologic inhibition of SR impede migration, whereas
d
-serine activates the process. Thus, in neuronal migration, glutamate stimulates Bergmann glia to form and release
d
-serine, which, together with glutamate, activates NMDA receptors on granule neurons, chemokinetically enhancing migration.
Dopamine D1 receptors involved in locomotor activity and accumbens neural responses to prediction of reward associated with place
Authors: Tran Anh Hai , Tamura Ryoi , Uwano Teruko , Kobayashi Tsuneyuki , Katsuki Motoya , Ono Taketoshi
Published: February 2005

Predicting reward is essential in learning approach behaviors. Dopaminergic activity has been implicated in reward, movement, and cognitive processes, all essential elements in learning. The nucleus accumbens (NAc) receives converging inputs from corticolimbic information-processing areas and from mesolimbic dopamine neurons originating in the ventral tegmental area. Previously, we reported that in mice, a dopamine D2 receptor knockout (D2R-KO) eliminated the prereward inhibitory response, increased place-field size of NAc neurons, and reduced locomotor activity without marked change in intracranial self-stimulation (ICSS) behavior. The present study investigated the specific contribution of dopamine D1 receptor (D1R) in mediating reward, locomotor activity, and spatial associative processes and in regulating NAc neural responses. In contrast to D2R-KO animals, here we find D1R-KO in mice selectively eliminated the prereward excitatory response and decreased place-field size of NAc neurons. Furthermore, D1R-KO impaired ICSS behavior, seriously reduced locomotor activity, and retarded acquisition of a place learning task. Thus, the present results suggest that D1R may be an important determinant in brain stimulation reward (ICSS) and participates in coding for a type of reward prediction of NAc neurons and in spatial learning.
Cold stress-induced protein Rbm3 binds 60S ribosomal subunits, alters microRNA levels, and enhances global protein synthesis
Authors: Dresios John , Aschrafi Armaz , Owens Geoffrey C. , Vanderklish Peter W. , Edelman Gerald M. , Mauro Vincent P.
Published: February 2005

The expression of Rbm3, a glycine-rich RNA-binding protein, is enhanced under conditions of mild hypothermia, and Rbm3 has been postulated to facilitate protein synthesis at colder temperatures. To investigate this possibility, Rbm3 was overexpressed as a c-Myc fusion protein in mouse neuroblastoma N2a cells. Cells expressing this fusion protein showed a 3-fold increase in protein synthesis at both 37°C and 32°C compared with control cells. Although polysome profiles of cells expressing the fusion protein and control cells were similar, several differences were noted, suggesting that Rbm3 might enhance the association of 40S and 60S ribosomal subunits at 32°C. Studies to assess a direct interaction of Rbm3 with ribosomes showed that a fraction of Rbm3 was associated with 60S ribosomal subunits in an RNA-independent manner. It appeared unlikely that this association could explain the global enhancement of protein synthesis, however, because cells expressing the Rbm3 fusion protein showed no substantial increase in the size of their monosome and polysome peaks, suggesting that similar numbers of mRNAs were being translated at approximately the same rates. In contrast, a complex that sedimented between the top of the gradient and 40S subunits was less abundant in cells expressing recombinant Rbm3. Further analysis showed that the RNA component of this fraction was microRNA. We discuss the possibility that Rbm3 expression alters global protein synthesis by affecting microRNA levels and suggest that both Rbm3 and microRNAs are part of a homeostatic mechanism that regulates global levels of protein synthesis under normal and cold-stress conditions.