bluuebunny/crossref_metadata_2025_split huggingface dataset:
Climate change effects on carbon and nitrogen mineralization in peatlands through changes in soil quality
Authors: Keller Jason K. , White Jeffrey R. , Bridgham Scott D. , Pastor John 
Published: December 2004

AbstractClimate change will directly affect carbon and nitrogen mineralization through changes in temperature and soil moisture, but it may also indirectly affect mineralization rates through changes in soil quality. We used an experimental mesocosm system to examine the effects of 6‐year manipulations of infrared loading (warming) and water‐table level on the potential anaerobic nitrogen and carbon (as carbon dioxide (CO2) and methane (CH4) production) mineralization potentials of bog and fen peat over 11 weeks under uniform anaerobic conditions. To investigate the response of the dominant methanogenic pathways, we also analyzed the stable isotope composition of CH4produced in the samples. Bog peat from the highest water‐table treatment produced more CO2than bog peat from drier mesocosms. Fen peat from the highest water‐table treatment produced the most CH4. Cumulative nitrogen mineralization was lowest in bog peat from the warmest treatment and lowest in the fen peat from the highest water‐table treatment. As all samples were incubated under constant conditions, observed differences in mineralization patterns reflect changes in soil quality in response to climate treatments. The largest treatment effects on carbon mineralization as CO2occurred early in the incubations and were ameliorated over time, suggesting that the climate treatments changed the size and/or quality of a small labile carbon pool. CH4from the fen peat appeared to be predominately from the acetoclastic pathway, while in the bog peat a strong CH4oxidation signal was present despite the anaerobic conditions of our incubations. There was no evidence that changes in soil quality have lead to differences in the dominant methanogenic pathways in these systems. Overall, our results suggest that even relatively short‐term changes in climate can alter the quality of peat in bogs and fens, which could alter the response of peatland carbon and nitrogen mineralization to future climate change.
Scale‐dependent climate signals drive breeding phenology of three seabird species
Authors: Frederiksen Morten , Harris Michael P. , Daunt Francis , Rothery Peter , Wanless Sarah 
Published: December 2004

AbstractBreeding at the right time is essential for animals in seasonal climates in order to ensure that the energy demands of reproduction, particularly the nutritional requirements of growing young, coincide with peak food availability. Global climate change is likely to cause shifts in the timing of peak food availability, and in order to adapt successfully to current and future climate change, animals need to be able to adjust the time at which they initiate breeding. Many animals use environmental cues available before the breeding season to predict the seasonal peak in food availability and adjust their phenology accordingly. We tested the hypothesis that regulation of breeding onset should reflect the scale at which organisms perceive their environment by comparing phenology of three seabird species at a North Sea colony. As predicted, the phenology of two dispersive species, black‐legged kittiwake (Rissa tridactyla) and common guillemot (Uria aalge), correlated with a large‐scale environmental cue (the North Atlantic Oscillation), whereas a resident species, European shag (Phalacrocorax aristotelis), was more affected by local conditions (sea surface temperature) around the colony. Annual mean breeding success was lower in late years for European shags, but not for the other two species. Since correlations among climate patterns at different scales are likely to change in the future, these findings have important implications for how migratory animals can respond to future climate change.
Mediating the War of Olives and Pines: Consensus‐Based Land‐Use Planning in a Multicultural Setting
Authors: Levine Hephzibah 
Published: December 2004

The proposed Nahal Tzalmon national park lies in the Galilee region of northern Israel. It encompasses land of unique natural beauty, some of which is occupied by Arab‐Israeli families. Statutory plans defining the park's boundaries were enacted more than twenty years ago. Despite ongoing preparation, however, the park has not yet opened to the public, in part because of continuous conflict between the Israeli government authorities and the resident families over property rights affecting construction, land use, and nature preservation.In 2000, after a long period of stagnation and discord, the Joint Environmental Mediation Service ( JEMS), guided by its founding organizations — the Consensus Building Institute and the Israel–Palestine Center for Research and Information — led a mediation process in the region. This was the first such process in the history of Israeli land‐use planning. The mediation resulted in a settlement that was agreed to and signed by nearly all parties on July 8, 2004. The agreement allows residents to remain on their land and it includes incentives, such as park employment, to ensure that they help preserve the natural environment. Plans based on this agreement are currently undergoing state ratification, although several implementation challenges are yet to be resolved.This case points to the importance of having a mediation team knowledgeable about and sensitive to local cultural norms and the difficulties of ensuring appropriate representation in the absence of a strong civic culture and organized advocacy groups. It also highlights the requisite for ensuring that all parties thoroughly understand the consensus building process and how it fits in with established bureaucratic procedures, as well as the critical need to secure strong support from implementing agencies at the outset.
Chronic ultraviolet radiation modulates epidermal differentiation as it up‐regulates transglutaminase 1 and its substrates
Authors: Lee Dae‐Sung , Quan Gen , Choi Jee‐Young , Kim Soo‐Youl , Lee Seung‐Chul 
Published: December 2004

Background: Ultraviolet radiation (UVR) stimulates cellular mitosis, which leads to epidermal hyperplasia. On the basis of hypothesis that chronic UVR may modulate differentiation as well as epidermal hyperplasia, we evaluated the modulation of markers of epidermal differentiation, such as transglutaminase 1 (TGase 1), filaggrin and loricrin, by chronic UVR in vivo.Methods: Total TGase activities assay or in situ TGase activities were measured in human and mouse skin. TGase 1 expression was identified by immunohistochemical staining in human skin. In the human, the pre‐auricular skin of face was used for samples of chronic UVR, and the post‐auricular skin was selected as non‐UVR control. The changes of filaggrin and loricrin were identified by western immunoblots.Results: In human and mouse epidermis, chronic UVR induced the increase of in situ TGase activities or total TGase activities as it up‐regulated TGase 1 expression in the epidermis. As the substrates of TGase 1, chronic UVR induced the up‐regulation of filaggrin and loricrin in mouse epidermis as well. At the same time, chronic UVR induced the marked epidermal hyperplasia in human and mouse skin.Conclusion: Chronic UVR stimulates epidermal differentiation as it up‐regulates TGase 1 and its substrates. The modified epidermal differentiation is balanced with epidermal hyperplasia, leading to the maintenance of epidermal homeostasis in the UV‐irradiated epidermis.
Flt3 ligand and the Flt3 receptor regulate hematopoietic cell migration by modulating the SDF-1α(CXCL12)/CXCR4 axis
Authors: Fukuda Seiji , Broxmeyer Hal E. , Pelus Louis M. 
Published: December 2004

AbstractFlt3 ligand (FL) enhances hematopoietic cell proliferation and facilitates hematopoietic stem cell mobilization in vivo, while the stromal-derived factor 1α (SDF-1α, CXC ligand 12 [CXCL12])/CXC receptor 4 (CXCR4) axis is critical for their homing and trafficking. We investigated if FL and its receptor, Flt3, functionally interact with CXCL12/CXCR4 to regulate hematopoietic cell migration. FL stimulated chemokinetic activity when used alone, but synergistically enhanced short-term migration of CD34+ cells, Ba/F3 cells expressing human Flt3 (Ba/F3-Flt3), and human RS4;11 acute leukemia cells, induced by CXCL12. Moreover, overexpression of constitutively activated internal tandem duplication (ITD)–Flt3 mutants in Ba/F3 cells dramatically enhanced migration toward CXCL12. In Ba/F3-Flt3 cells, synergistic cell migration to FL plus CXCL12 was associated with enhanced phosphorylation of mitogen-activated protein kinase p42/p44 (MAPKp42/p44), cyclic adenosine monophosphate response element binding protein (CREB), and Akt, and was partially inhibited by pretreatment of cells with selective inhibitors for MAPKp42/p44, protein kinase A (PKA), or phosphatidylinositol 3–kinase (PI3-kinase), implicating these pathways in migration to FL plus CXCL12. In contrast, prolonged exposure of CD34+ or Ba/F3-Flt3 cells to FL down-regulated CXCR4 expression, inhibited CXCL12-mediated phosphorylation of MAPKp42/p44, CREB, and Akt, and impaired migration toward CXCL12. These findings suggest that FL/Flt3 may facilitate hematopoietic cell migration/homing and mobilization by enhancing or inhibiting CXCL12/CXCR4 signaling pathways and that the FL/Flt3 axis participates in trafficking of normal and transformed hematopoietic cells.
SATB1 family protein expressed during early erythroid differentiation modifies globin gene expression
Authors: Wen Jie , Huang Suming , Rogers Heather , Dickinson Liliane A. , Kohwi-Shigematsu Terumi , Noguchi Constance Tom 
Published: December 2004

AbstractSpecial AT-rich binding protein 1 (SATB1) nuclear protein, expressed predominantly in T cells, regulates genes through targeting chromatin remodeling during T-cell maturation. Here we show SATB1 family protein induction during early human adult erythroid progenitor cell differentiation concomitant with ϵ-globin expression. Erythroid differentiation of human erythroleukemia K562 cells by hemin simultaneously increases γ-globin and down-regulates SATB1 family protein and ϵ-globin gene expression. Chromatin immunoprecipitation using anti-SATB1 anti-body shows selective binding in vivo in the β-globin cluster to the hypersensitive site 2 (HS2) in the locus control region (LCR) and to the ϵ-globin promoter. SATB1 overexpression increases ϵ-globin and decreases γ-globin gene expression accompanied by histone hyperacetylation and hypomethylation in chromatin from the ϵ-globin promoter and HS2, and histone hypoacetylation and hypermethylation associated with the γ-globin promoter. In K562 cells SATB1 family protein forms a complex with CREB-binding protein (CBP) important in transcriptional activation. In cotransfection experiments, increase in ϵ-promoter activity by SATB1 was amplified by CBP and blocked by E1A, a CBP inhibitor. Our results suggest that SATB1 can up-regulate the ϵ-globin gene by interaction with specific sites in the β-globin cluster and imply that SATB1 family protein expressed in the erythroid progenitor cells may have a role in globin gene expression during early erythroid differentiation. (Blood. 2005;105:3330-3339)
Enhancing the immunostimulatory function of dendritic cells by transfection with mRNA encoding OX40 ligand
Authors: Dannull Jens , Nair Smita , Su Zhen , Boczkowski David , DeBeck Christian , Yang Benjamin , Gilboa Eli , Vieweg Johannes 
Published: December 2004

AbstractThe objective of this study was to investigate whether the immunostimulatory properties of human monocyte-derived dendritic cells (DCs) could be enhanced by triggering OX40/OX40L signaling. Since monocyte-derived DCs possess only low-cell surface levels of OX40L in the absence of CD40 signaling, OX40L was expressed by transfection of DCs with the corresponding mRNA. We show that OX40L mRNA transfection effectively enhanced the immunostimulatory function of DCs at multiple levels: OX40L mRNA transfection augmented allogeneic and HLA class II epitope-specific CD4+ T-cell responses, improved the stimulation of antigen-specific cytotoxic T lymphocytes (CTLs) in vitro without interfering with the prostaglandin E2 (PGE2)–mediated migratory function of the DCs, and facilitated interleukin 12 p70 (IL-12p70)–independent T helper type 1 (Th1) polarization of naive CD4+ T-helper cells. Furthermore, vaccination of tumor-bearing mice using OX40L mRNA–cotransfected DCs resulted in significant enhancement of therapeutic antitumor immunity due to in vivo priming of Th1-type T-cell responses. Our data suggest that transfection of DCs with OX40L mRNA may represent a promising strategy that could be applied in clinical immunotherapy protocols, while circumventing the current unavailability of reagents facilitating OX40 ligation.
Über die Reaktion von Benzhydroxamsäureestern mit Diazomethan
Authors: Blaser R. , Imfeld P. , Schindler O. 
Published: December 2004

AbstractBenzhydroxamsäure und im Phenylkern substituierte Analoge bilden mit α‐Halogencarbonsäureestern Benzhydroxamsäureester (IV in Tab.1). Diese reagierten mit Diazomethan stereospezifisch zu den entsprechenden syn‐Methyl‐benzhydroximsäureestern (V in Tab.1.). Die Zuordnung der Stereochemie basiert auf dem Aufbau von XIV und XVIII aus den beiden 3‐O‐Methyl‐benzhydroxamsäuren XII und XIII, deren Stereochemie gesichert ist.
Stoffwechselprodukte von Mikroorganismen. 75. Mitteilung [1]. Synthese des Ferrichroms; 2. Teil
Authors: Keller‐Schierlein W. , Maurer B. 
Published: December 2004

AbstractFerrichrome, a biologically active sideramine isolated from cultures of several strains of fungi, was synthesized starting from δ‐nitro‐L‐norvaline and glycine. The intermediate trinitro‐cyclohexapeptide 17 could be obtained in high yield by SCHWYZER's method from the corresponding open‐chain hexapeptide 16.
Konstitution von Palustridin
Authors: Green C. L. , Mayer C. , Eugster C. H. 
Published: December 2004

AbstractPalustridine (I, C18H31N3O3), which co‐occurs with palustrine in Equisetum palustre L., has been shown to be Nb‐formyl‐palustrine. Hydrolysis with dilute mineral acid yields palustrine, and formylation of the latter gives palustridine. The mass spectral fragmentation pattern differs from that of palustrine, and is very similar to that of Nb‐acetylpalustrine. The earlier proposed skeleton of palustrine is independently confirmed.
Zur Kenntnis der VAN SLYKE‐Reaktion des Muscimols und anderer 3‐Hydroxyisoxazole. 32. Mitteilung über Inhaltsstoffe von Fliegenpilzen
Authors: Fràter‐Schröder M. , Good R. , Eugster C. H. 
Published: December 2004

Abstract3‐Hydroxyisoxazole werden unter sehr milden Bedingungen zu instabilen N‐Nitrosoverbindungen nitrosiert, welche in verdünnter Essigsäure rasch in N2O und CO2 zerfallen. Die Reaktion kann als Mikromethode zur Erkennung von 3‐Hydroxyisoxazolen benutzt werden.Die Synthese mehrerer neuer 3‐Hydroxyisoxazole wird angegeben.
Protonenresonanzspektren von Pteridinen (VI). Mono‐ und Dikationen von 2‐Amino‐4‐oxo‐3, 4‐dihydropteridinen
Authors: Dieffenbacher A. , Philipsborn W. 
Published: December 2004

AbstractProton NMR. spectra of 18 pteridines have been measured in strongly acidic solutions. In trifluoroacidic acid mono‐cations are formed whereas in fluorosulfonic acid double protonation occurs. For the first time di‐cations of pteridines are described, and the structures of these species are determined by NMR. and UV. data. The chemical shifts of the NH2 protons in the mono‐cations and of the methyl protons in the mono‐ and di‐cations follow linear correlations with the basic pKa values. From NMR. variable temperature measurements the energy barrier to internal rotation in the amidinium system has been ddtermined for both cations. The results are discussed with particular regard to the structure of the mono‐and di‐cations.
Zur Deutung des UV.‐Spektrums von Pyridin‐N‐oxid
Authors: Seibold K. , Wagnière G. , Labhart H. 
Published: December 2004

AbstractFrom measurements of the influence of an electric field on the absorption spectrum of pyridine‐N‐oxide it is concluded that the 330 nm band is polarized perpendicular to the dipole moment, while the 280 nm transition moment lies parallel. Furthermore from these experiments the dipole moments in both excited states have been determined (Table 1). PARISER‐PARR‐POPLE‐calculations as well as CNDO‐calculations admit an assignment of the 330 nm band to anA1→B1, π → π* transition and of the 280 nm band to anA1→A1, π → π* transition. Thereby energy, polarization, intensity of the transition, and the dipole moments of the excited states have been taken into consideration. This assignment does not exclude the possibility of a weakn‐π* transition at approximately the same wavelength as theA1→B1transition.
Lösungsmitteleffekte in Kernresonanzspektren gesättigter Kohlenwasserstoffe (III). Unterscheidung unpolarer und polarer Effekte bei Steroiden
Authors: Winkler T. , von Philipsborn W. 
Published: December 2004

AbstractBenzene‐induced proton NMR. solvent shifts of methyl and methylene groups in 25 acyclic and cyclic saturated hydrocarbons have been studied. The dependence of magnitude and sign of these unpolar effects upon the molecular shape is again demonstrated. Solvent shifts in polar solutes (hydroxy‐ and keto‐steroids) are shown to originate from a superposition of polar and unpolar effects. The implications for the interpretation of small solvent shifts in polar solutes are discussed.
Tetrafluordiazabuten‐Derivate aus Chlorcyan
Authors: Alt K. O. , Weis C. D. 
Published: December 2004

AbstractCyanogenchloride reacts in liquid hydrogenfluoride with fluorides of some aliphatic hydrocarbons to yield derivatives of 2,4,4,4‐tetrafluoro‐1,3‐diazabut‐2‐ene. The mechanism of its formation is explained in terms of an intermediate fluorinated linear dimerization product of cyanogenchloride. Reactions of the N‐trifluoromethylgroup are reported.
Utilisation d'ylides du phosphore non stabilisés en chimie des sucres. II. Action du méthylthiométhylène‐triphénylphosphorane sur les aldéhydo‐surces
Authors: Tronchet J. M. J. , Jaccard‐Thorndahl Mme S. , Baehler Br. 
Published: December 2004

AbstractThe action of methylthiomethylene‐triphenylphosphorane on 2,3: 4,5‐di‐O‐isopropylidene‐Aldehydo‐‐L‐arabinose led with good yield to the corresponding unsaturated sugar which underwent electrophilic addition with a high regiospecificity. This provides a useful new route for a one‐carbon chain extension in the carbohydrate series.
Organische Phosphorverbindungen XXXVIII. Darstellung und Eigenschaften von Tris‐(dialkoxyphosphonyl‐methyl)‐, Tris‐(alkoxyphosphinyl‐methyl)‐und Tris‐(oxophosphoranyl‐methyl)‐phosphinsäureestern sowie der entsprechenden Säuren [1]
Authors: Maier Ludwig 
Published: December 2004

AbstractTris‐chloromethyl‐phosphine oxide, (ClCH2)3 PO(I), is obtained by chlorination of (HOCH2)3PO with PCl5 or (C6H5)3PCl2, and also by oxidation of (CICH2)3PO and (ClCh2)2(CH3)PO. High yields of tris‐(dialkyloxyphosphonly‐methyl)‐phosphine oxides, [RO2(O)PCH2]2PO (II) (RCH3, C2H5, iso‐C3H7, n‐C4H9, 2‐ ethyl‐hexyl), tris (alkyloxyphosphinyl‐methyl)‐phosphine oxides, [R2(O)PCH2]3PO(R = C6H5, CH3) are obtained by heating tris‐chloromethyl‐phosphine oxides, [(RO) (R′) (O)PCH2]3PO (R = C4H9, R′ C6H5) and tris‐(oxophosphoranyl‐phosphine oxides with phosphites, phosphonites and phosphinites, respectively, at 170–180°C for several hours. Compounds II possess an extraordinarily high absorption capacity. Thus a warm. 2% solution of II (R = C2H5) in benzene solidifies completely on cooling so that no benzene can be poured off.Tris‐dihydroxyphosphonyl‐methyl)‐phosphine oxide, [(HO)2(O)PCH2]3PO, obtained by hydrolysis of II (R  C2H5) with refluxing conc. HCl or by thermal decomposition of II (R  iso‐C3H7) at 190°, titrates in aqueous solution as a hexabasic acid with breaks at pH = 4,4 (three equivalents) and pH = 10,7 (three equivalents). It forms crystalline salts with amines, alkali and alkaline earth metals, and is an excellent chelating agent.The 1H‐ and 31−P‐NMR. spectra of all the compounds prepared are discussed.
Photochemische Reaktionen. 52. Mitteilung [1]. Zur Photochemie von α,β‐ungesättigten cyclischen Ketonen: Spezifische Reaktionen der n,π*‐ und π,π*‐Triplettzustände von O‐Acetyl‐testosteron und 10‐Methyl‐Δ1,9‐octalon‐(2)
Authors: Belluš D. , Kearns D. R. , Schaffner K. 
Published: December 2004

AbstractThe photochemistry of the conjugated cyclohexenones O‐acetyl testosterone (1) and 10‐methyl‐Δ1,9‐octalone‐(2) (24) has been investigated in detail. The choice of reaction paths of both ketones depends strongly on the solvent used. In t‐butanol, a photostationary equilibrium 1 ⇄ 3 is reached which is depleted solely by the parallel rearrangement 1 → 5 (Chart 1; for earlier results on these reactions see [2a] [6] [7]). In benzene, double bond shift 1 → 16 (Chart 3) occurs instead, which is due to hydrogen abstraction from a ground‐state ketone by the oxygen of an excited ketone as the primary photochemical process. In toluene, the major reaction is solvent incorporation (1 → 17, Chart 4) through hydrogen addition to the β‐carbon of the enone, accompanied by double bond shift and formation of saturated dihydroketone as the minor reactions. Contrary in part to an earlier report [19], the photochemical transformation of the bicyclic enoné 24 exhibit a similar solvent dependence. The corresponding products 25–29 are summarized in Chart 5 and Table 1.Sensitization and quenching experiments established the triplet nature of the above reactions of 1 and 24. Based on STERN‐VOLMER analyses of the quenching data (cf. Figures 2, 4–8, and Table 3), rearrangement, double bond reduction and toluene addition are attributed to one triplet state of the enones which is assigned tentatively as 3(π, π*) state, and the double bond shift is attributed to another triplet assigned as 3(n, π*) state (cf. Figure 9).The stereospecific rearrangement of the 1α‐deuterated ketone 2 to the 4β‐deuterio isomer 4 shows the reaction to proceed with retention at C‐1 and inversion at C‐10.The 4‐substituted testosterone derivatives 33–36 (Chart 8) were found to be much less reactive in general than 1. In particular, 4‐methyl ketone 33 remains essentially unchanged on irradiation in t‐butanol, benzene and toluene.
Spectres de masse des composés organiques. 4e communication. Fragmentation de l'hexane
Authors: Liardon Rémy , Gäumann Tino 
Published: December 2004

AbstractWith the help of metastable peaks and high resolution, and by making extensive use of deuterated species we determined the main paths of fragmentation of hexane. Beside the simple splitting of a CC‐bond there are a series of internal rearrangement reactions. The loss of neutral fragments from alkyl ions is often, but not always, statistical. A small primary (0.96) and an even smaller (0.99) secondary isotope effect for a hydrogen transfer can be observed.
Kinetische Untersuchungen über Substitutionsreaktionen an Metallkomplexen. 11. Mitteilung [1]. Die Bildung von Tetrakis(triäthylphosphit)nickel(0) aus Nickelocen — eine Reaktion dritter Ordnung
Authors: Werner H. , Harder V. , Deckelmann E. 
Published: December 2004

AbstractNickelocene Ni(π‐C5H5)2 reacts with triethylphosphite in dioxane at 50–70° to give Ni[P(OC2H5)3]4. Kinetic studies confirm a third‐order rate law for this ligand substitution process with the activation parameters Ea = 6.8 kcal/mole and ΔS≠ = −53.8 e. u. The mechanistic implications of these results are discussed.