bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anthropogenic influences on Zuni agricultural soils
Authors: Homburg Jeffrey A. , Sandor Jonathan A. , Norton Jay B. 
Published: September 2005

AbstractFarmers in the Zuni area of the semiarid American Southwest have successfully cultivated maize and other crops for over three millennia without using artificial fertilizers. Zuni agricultural fields are among the oldest, more or less continuously cultivated areas in the United States. Traditional Zuni agriculture is based on runoff farming, a system whereby runoff and organic‐rich sediment generated in small watersheds are captured and directed onto fields for crop use. We conducted a study to compare soil properties associated with paired and unpaired cultivated, abandoned, and uncultivated fields to evaluate the long‐term effects of cultivation on soil quality. Sampling and analytical methods of this research are especially applicable to geoarchaeological studies of anthropogenic effects on soil fertility and agricultural sustainability in ancient and traditional historical farming systems. Results of the Zuni soil study indicate that cultivation has altered some soil properties, including bulk density, organic carbon, total nitrogen, and C:N ratios in paired fields, but there is no indication that agricultural soils are degraded. This assessment supports the perception of Zuni farmers that long‐term cultivation has not caused a decline in agricultural productivity. © 2005 Wiley Periodicals, Inc.
Experimental hearths and the thermal alteration of Caliche on the Southern High Plains
Authors: Backhouse Paul N. , Johnson Eileen , Brackenreed‐Johnston Alexander , Buchanan Briggs 
Published: September 2005

AbstractThroughout the Holocene, caliche has been a ubiquitous technological resource for the people of the Southern High Plains. Archaeological sites on the Southern High Plains often contain thermal features that appear to utilize caliche nodules in various cultural processes. These processes usually involve some degree of thermal dynamic alteration to the caliche, identified in the archaeological record as fire‐scorched or blackened nodules. Previous studies of the pyrodynamic properties of caliche have focused on quantification of color and fracture patterns within a laboratory setting, without direct involvement of cultural processes or problems associated with thermal features. Thermal alteration variables of caliche are examined from an actualistic perspective, utilizing previously excavated basin feature geometry and local caliche outcrops. Results indicate that sustained, intense heating of caliche (above 204°C) causes significant, but variable, structural transformations at the specimen level. The experimental use of shallow basin hearths demonstrates that hearth structures were easily capable of achieving and sustaining temperatures that would result in the physical alteration of individual caliche nodules, defined here as hearthstones. The broader implications of this study suggest that the interpretation of archaeological hearthstone assemblages should reflect variability, as observed during this experiment. © 2005 Wiley Periodicals, Inc.
Late Chiribaya agriculture and risk management along the arid Andean coast of southern Perú, A.D. 1200–1400
Authors: Zaro Gregory , Alvarez Adán Umire 
Published: September 2005

AbstractRecent investigations at the coastal spring site of Wawakiki in southern Perú have identified an intensive, late pre‐Hispanic agricultural production strategy along a sea cliff some 30 km north of the Ilo River. Excavations identified buried stone‐faced agricultural terraces underlying Spanish colonial and post‐colonial furrows, and long irrigation canals that transported water along steep hill slopes from inland springs. Depositional patterns, cultural debris, and calibrated radiocarbon age ranges suggest the site was farmed most intensively between A.D. 1200 and 1400, a period characterized by prolonged highland drought and recurrent El Niño–induced floods in southern Perú. Farmers transformed this arid coastal promontory into a productive agricultural landscape by exploiting multiple spring sources, steep canals, and stone‐faced terraces in an area where water is a very limited commodity and steep barren hills are highly prone to erosion. Furthermore, high‐relief terrain left much of the agricultural infrastructure well protected from periodic floods. © 2005 Wiley Periodicals, Inc.
Galectin‐3 expression in papillary thyroid carcinoma: Relation to histomorphologic growth pattern, lymph node metastasis, extrathyroid invasion, and tumor size
Authors: Cvejic Dubravka S. , Savin Svetlana B. , Petrovic Ivana M. , Paunovic Ivan R. , Tatic Svetislav B. , Havelka Marija J. 
Published: September 2005

AbstractBackground.Galectin‐3 has been recently recognized as a promising presurgical marker of thyroid malignancy.Methods.Galectin‐3 expression was examined immunohistochemically in 202 specimens of papillary thyroid carcinoma (PTC) in relation to histomorphologic subtypes and clinicopathologic data.Results.The sensitivity of galectin‐3 immunostaining versus conventional histology was 98% (100 of 102) for classical PTC, 85.2% (46 of 54) for follicular variant, and 50% (23 of 46) for follicular/solid variant of PTC. All cases (n = 36) involving lymph node metastases and 42 of 45 cases with extrathyroid invasion expressed galectin‐3. However, among the galectin‐3–positive cases (n = 169), 133 were without lymph node metastases, and 127 were without extrathyroid invasion. Galectin‐3 expression was not related to the size of intrathyroid PTC.Conclusions.Galectin‐3 immunohistochemical expression itself is not an indicator of local metastatic spread or extrathyroid invasion of PTC, thus being irrelevant clinically from this aspect. Galectin‐3 is an excellent marker for classical PTC but must be used with caution in diagnosing unconventional variants of PTC because of the possibility of false‐negative results. © 2005 Wiley Periodicals, Inc. Head Neck 27: XXX–XXX, 2005
Signaling pathways implicated in α‐melanocyte stimulating hormone‐induced lipolysis in 3T3‐L1 adipocytes
Authors: Cho Kyung‐Joo , Shim Jung‐Hyun , Cho Min‐Chul , Choe Yong‐Kyung , Hong Jin‐Tae , Moon Dong‐Chul , Kim Jong‐Wan , Yoon Do‐Young 
Published: September 2005

AbstractMelanocortins, besides their central roles, have also recently been reported to regulate adipocyte metabolism. In this study, we attempted to characterize the mechanism underlying α‐melanocyte‐stimulating hormone (MSH)‐induced lipolysis, and compared it with that of the adrenocorticotrophin hormone (ACTH) in 3T3‐L1 adipocytes. Similar to ACTH, MSH treatment resulted in the release of glycerol into the cell supernatant. The activity of hormone‐sensitive lipase, a rate‐limiting enzyme, which is involved in lipolysis, was significantly increased by MSH treatment. In addition, a variety of kinases, including protein kinase A (PKA) and extracellular signal‐regulated kinase (ERK) were also phosphorylated as the result of MSH treatment, and their specific inhibitors caused a reduction in MSH‐induced glycerol release and HSL activity, indicating that MSH‐induced lipolysis was mediated by these kinases. These results suggest that PKA and ERK constitute the principal signaling pathways implicated in the MSH‐induced lipolytic process via the regulation of HSL in 3T3‐L1 adipocytes. J. Cell. Biochem. © 2005 Wiley‐Liss, Inc.
A density functional study of propylene glycol conversion to propanal and propanone of various acid‐catalyzed reaction models: A water‐addition effect
Authors: Rungnim Chompoonut , Ruangpornvisuti Vithaya 
Published: September 2005

AbstractThe acid‐catalyzed models on reaction mechanisms of pinacol rearrangement of propylene glycol conversion to propanal and propanone have been investigated using the density functional method at 298.15 K. Thermodynamic quantities of activation steps of four water‐addition models were obtained. The number of added water interacting with the transition states of three concerted pathways has obviously affected the product ratio. The relative energetic profiles of the conversion reactions of all solvation models have been comparatively displayed. Estimation of the percent ratio of product composition computed from activation free energies of each acid‐catalyzed reaction model was carried out. The percent ratios of propanal and propanone were decreased as the number of added water increased. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1592–1599, 2005
Effect of the axial cysteine ligand on the electronic structure and reactivity of high‐valent iron(IV) oxo‐porphyrins (Compound I): A theoretical study
Authors: Choe Yoong‐Kee , Nagase Shigeru 
Published: September 2005

AbstractThe effect of axial ligands on the reactivity of high‐valent iron(IV) oxo‐porphyrins (Compound I) was investigated using the B3LYP hybrid density functional method. We studied alkane hydroxylation using four models: Compound I with thiolate, imidazole, phenolate, and chloride anions as axial ligands. The first three ligands were employed as models for cysteinate, histidine, and tyrosinate, respectively. Our calculations show that anionic ligands and neutral ligands favor different electronic states for stationary points in the reaction coordinate, and the calculated energy barrier and energy of several reaction intermediates show similar values. A remarkable effect of axial ligands was found in the final product release step. Our calculations show that the thiolate ligand weakens a bond between heme and an alcohol. In contrast, the imidazole ligand significantly increases the interaction between heme and an alcohol, which causes the catalytic cycle to be less efficient. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 1600–1611, 2005
Elevated expression of hypoxia inducible factor‐2α in terminally differentiating growth plate chondrocytes
Authors: Stewart Alan J. , Houston Brian , Farquharson Colin 
Published: September 2005

AbstractGrowth plate chondrocytes exist in a hypoxic environment where it is recognized that hypoxia‐inducible factor‐1α (HIF‐1α) is essential for their survival. Its regulation of chondrocyte viability may be mediated by the increased expression of vascular endothelial growth factor (VEGF) and glycolytic enzymes. However, the full chondrocyte response to hypoxia and the molecular control of VEGF expression in relation to growth plate differentiation and vascularization remains poorly understood. Using Percoll density gradient centrifugation, chick chondrocytes were separated into populations of different maturational phenotype. A differential display analysis of the populations showed highly upregulated expression of HIF‐2α mRNA during chondrocyte differentiation. HIF‐2α is a homologue of the HIF‐1α transcription factor, both of which play a role in the activation of a number of hypoxia responsive genes. HIF‐1α mRNA was also found to be expressed, although levels of expression were found to be similar in all of the chondrocyte fractions. The elevated expression of HIF‐2α during chondrocyte differentiation was accompanied by increased VEGF expression. Analysis of the murine chondrocyte cell line, ATDC5, which undergoes ordered maturation indicated that HIF‐2α, VEGF, placental growth factor, and glucose transporter‐1 expression all increased in parallel with chondrocyte differentiation. This observation was supported by immunohistochemistry on sections of mouse bone which showed staining corresponding to the presence of HIF‐2α in hypertrophic growth plate chondrocytes. The presence of HIF‐2α was also observed in articular chondrocytes but was restricted to the superficial tangential zone. HIF‐2α is, therefore, likely to be involved in the initiation of blood vessel formation and a metabolic shift in the growth plate, processes crucial for endochondral ossification. J. Cell. Physiol. 206: 435–440, 2006. © 2005 Wiley‐Liss, Inc.
Single cell analysis of PKC activation during proliferation and apoptosis induced by laser irradiation
Authors: Gao Xuejuan , Chen Tongsheng , Xing Da , Wang Fang , Pei Yihui , Wei Xunbin 
Published: September 2005

AbstractLaser irradiation has been shown to trigger cellular proliferation and apoptosis in various cell types. Studying the signaling pathways involved in the laser irradiation is important for understanding these processes. In present study, to monitor the protein kinase Cs (PKCs) activity in living cells in real time, we transfected and screened human lung adenocarcinoma cells (ASTC‐a‐1) stably expressing C kinase activity reporter (CKAR) constructed based on fluorescence resonance energy transfer (FRET) technique. The CKAR is a specific, reversible reporter of phosphorylation by PKCs and it can monitor the ongoing balance between PKCs and phosphatases. The increasing dynamics of PKCs activity is monitored during cell proliferation induced by low‐power laser irradiation (LPLI) (0.8 J/cm2) in serum‐starved ASTC‐a‐1 cells stably expressing CKAR reporter using FRET imaging on laser scanning confocal microscope and using spectrofluorometric analysis on a luminescence spectrometer, respectively. However, the decreasing dynamics of PKCs activity has been monitored in real time using FRET imaging for the cells treated with high fluence LPLI (60 J/cm2), which was previously found to induce cell apoptosis. Taken together, LPLI induces the ASTC‐a‐1 cell proliferation by specifically activating PKCs. However, PKCs activity decreases during cell apoptosis induced by high fluence LPLI. Our results indicate that PKCs play an important role in the laser irradiation‐induced biological effects. J. Cell. Physiol. 206: 441–448, 2006. © 2005 Wiley‐Liss, Inc.
Maitotoxin potently promotes Ca2+ influx in mouse spermatogenic cells and sperm, and induces the acrosome reaction
Authors: Treviño Claudia L. , De la Vega‐Beltrán José L. , Nishigaki Takuya , Felix Ricardo , Darszon Alberto 
Published: September 2005

AbstractMaitotoxin (MTX), a potent marine toxin, activates Ca2+ entry via nonselective cation channels in a wide variety of cells. The identity of the channels involved in MTX action remains unknown. In mammalian sperm, Ca2+ entry through store‐operated channels regulates a number of physiological events including the acrosome reaction (AR). Here we report that MTX produced an increase in the intracellular concentration of Ca2+ ([Ca2+]i) in spermatogenic cells that depended on extracellular Ca2+. Ni2+ and SKF96365 diminished the MTX‐activated Ca2+ uptake, at concentrations they inhibit store‐operated channels, and in a similar manner as they inhibit the Ca2+ influx activated following depletion of intracellular stores by thapsigargin (Tpg). In addition, MTX significantly increased [Ca2+]i in single mature sperm and effectively induced the AR with a half‐maximal concentration (ED50) of ∼1.1 nM. Notably, SKF96365 similarly inhibited the MTX‐induced increase in sperm [Ca2+]i and the AR triggered by the toxin, Tpg and zona pellucida. These results suggest that putative MTX‐activated channels may be involved in the Ca2+ influx required for mouse sperm AR. J. Cell. Physiol. 206: 449–456, 2006. © 2005 Wiley‐Liss, Inc.
Rate of oxygen consumption by isolated articular chondrocytes is sensitive to medium glucose concentration
Authors: Heywood Hannah K. , Bader Dan L. , Lee David A. 
Published: September 2005

AbstractCartilage tissue engineering typically involves the culture of isolated chondrocytes within a scaffold material. The oxygen tension within the engineered tissue is known to be an essential parameter for implant success. This will be sensitive to the oxygen consumption behavior of the embedded chondrocytes, which remains to be characterized. We report that the oxygen consumption of bovine articular chondrocytes is sensitive to glucose deprivation below 2.7 mM, increasing from a basal level of 9.6 × 10−16 to <18.4 × 10−16 mol/cell · h in 1.3 mM glucose. Further studies examined the influence of selecting high (18.4 mM) or low (5.1 mM) glucose medium on the oxygen tension in 2 mm thick cellular agarose constructs. A relative upregulation of oxygen consumption was observed in constructs cultured in low glucose medium. This resulted in the near‐anoxic oxygen concentration of 5 µM oxygen in constructs seeded with 40 × 106 cells/ml, compared to 57 µM in the corresponding high glucose culture. The upregulation of oxygen consumption generally corresponded to the inhibition of glycolysis, which is consistent with the Crabtree phenomenon. Medium osmolarity (316–600 mOsm) had minimal effects on chondrocyte oxygen consumption rate. In conclusion, glucose availability is a critical parameter that regulates the oxygen tension within tissue engineered constructs. J. Cell. Physiol. 206: 402–410, 2006. © 2005 Wiley‐Liss, Inc.
Cartducin, a paralog of Acrp30/adiponectin, is induced during chondrogenic differentiation and promotes proliferation of chondrogenic precursors and chondrocytes
Authors: Maeda Takashi , Jikko Akitoshi , Abe Makoto , Yokohama‐Tamaki Tamaki , Akiyama Hironori , Furukawa Souhei , Takigawa Masaharu , Wakisaka Satoshi 
Published: September 2005

AbstractWe previously reported that CORS26 gene, isolated from C3H10T1/2 cells treated with transforming growth factor‐β1, was predominantly expressed in cartilage. Because the gene product is a kind of secretory protein produced by cartilage tissue, we named it “cartducin”. Cartducin shares a similar modular organization to adipocyte‐derived hormone, adiponectin. In this study, we investigated cartducin function during chondrogenesis and cartilage development. In situ hybridization analysis showed that cartducin transcripts were restricted to the proliferating chondrocytes in the growth plate cartilage. Whole‐mount in situ hybridization revealed that the first significant induction of cartducin expression occurred in the sclerotome, which contains a chondrogenic cell lineage between days 9.5 and 10.5 postcoitus (p.c.) during mouse embryogenesis. Chondrogenic differentiation by combined treatment with bone morphogenetic protein‐2 and insulin induced cartducin expression along with type II and IX collagen expression in chondrogenic progenitor N1511 cells. To elucidate the direct action of cartducin on the cells, recombinant cartducin protein was expressed in and purified from Escherichia coli. The recombinant cartducin potentially forms homo‐oligomers and promoted the proliferation of chondrogenic progenitor N1511 cells, and chondrocytic HCS‐2/8 cells in a dose‐dependent manner. On the other hand, cartducin did not affect the production of sulfated glycosaminoglycan (sGAG) in these cells. These findings indicate that cartducin is a novel growth factor and plays important roles in regulating both chondrogenesis and cartilage development by its direct stimulatory action on the proliferation of chondrogenic precursors and chondrocytes. J. Cell. Physiol. 206: 537–544, 2006. © 2005 Wiley‐Liss, Inc.
Age affects ERK1/2 and NRF2 signaling in the regulation of GCLC expression
Authors: Li Muyao , Liu Rui‐Ming , Timblin Cynthia R. , Meyer Suzanne G. , Mossman Brooke T. , Fukagawa Naomi K. 
Published: September 2005

AbstractWe previously reported that activator protein‐1 (AP‐1) DNA binding activity was increased in vascular smooth muscle cells (VSMC) from old rats when exposed to high glucose or tumor necrosis factor (TNF‐α) (Li et al., 2003. J Cell Physiol 197:418–425). We have now examined the relationship between the age‐dependent activation of the ERK1/2–AP‐1 pathway and modulation of constitutive gene expression of the catalytic subunit of glutamate‐cysteine ligase (GCLC) in response to high glucose and TNF‐α. GCLC mRNA levels were higher in VSMC from old rats compared to young, a pattern consistent with its protein levels. To determine whether age‐related activation of ERK1/2‐AP‐1 signaling is responsible for the up‐regulation of GCLC, the MEK inhibitors, PD98059 and U0126, were used to block ERK1/2 in VSMC from old rats. An increase in GCLC with inhibitors was observed, diminishing the likelihood of ERK1/2‐AP‐1 activation as the up‐regulating signal for GCLC. However, the transcription factor Nrf2 was higher in nuclei and accompanied by increased Nrf2‐ARE binding in VSMC from old rats. Furthermore, MEK inhibitors increased nuclear Nrf2 and Nrf2/ARE binding. These data suggest opposing effects of Nrf2 and ERK1/2 signaling in the modulation of GCLC expression in old animals. J. Cell. Physiol. 206: 518–525, 2006. © 2005 Wiley‐Liss, Inc.
Automatic tuning of flexible interventional RF receiver coils
Authors: Venook Ross D. , Hargreaves Brian A. , Gold Garry E. , Conolly Steven M. , Scott Greig C. 
Published: September 2005

AbstractMicrocontroller‐based circuitry was built and tested for automatically tuning flexible RF receiver coils at the touch of a button. This circuitry is robust to 10% changes in probe center frequency, is in line with the scanner, and requires less than 1 s to tune a simple probe. Images were acquired using this circuitry with a varactor‐tunable 1‐inch flexible probe in a phantom and in an in vitro porcine knee model. The phantom experiments support the use of automatic tuning by demonstrating 30% signal‐to‐noise ratio (SNR) losses for 5% changes in coil center frequency, in agreement with theoretical calculations. Comparisons between patellofemoral cartilage images obtained using a 3‐inch surface coil and the surgically‐implanted 1‐inch flexible coil reveal a worst‐case local SNR advantage of a factor of 4 for the smaller coil. This work confirms that surgically implanted coils can greatly improve resolution in small‐field‐of‐view (FOV) applications, and demonstrates the importance and feasibility of automatically tuning such probes. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Iterative RF pulse design for multidimensional, small‐tip‐angle selective excitation
Authors: Yip Chun‐yu , Fessler Jeffrey A. , Noll Douglas C. 
Published: September 2005

AbstractThe excitation k‐space perspective on small‐tip‐angle selective excitation has facilitated RF pulse designs in a range of MR applications. In this paper, k‐space‐based design of multidimensional RF pulses is formulated as a quadratic optimization problem, and solved efficiently by the iterative conjugate‐gradient (CG) algorithm. Compared to conventional design approaches, such as the conjugate‐phase (CP) method, the new design approach is beneficial in several regards. It generally produces more accurate excitation patterns. The improvement is particularly significant when k‐space is undersampled, and it can potentially shorten pulse lengths. A prominent improvement in accuracy is also observed when large off‐resonance gradients are present. A further boost in excitation accuracy can be accomplished in regions of interest (ROIs) if they are specified together with “don't‐care” regions. The density compensation function (DCF) is no longer required. In addition, regularization techniques allow control over integrated and peak pulse power. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.
Ghost artifact removal using a parallel imaging approach
Authors: Winkelmann Richard , Börnert Peter , Dössel Olaf 
Published: September 2005

AbstractParallel imaging techniques, which use several receive coils simultaneously, have been shown to enable a significant scan time reduction by subsampling k‐space. Nevertheless, the data acquired with multiple coils in parallel exhibit some redundancy if the number of receive coils exceeds the subsampling factor. This redundancy leads to an overdetermination of the reconstruction problem, which is generally used to optimize the signal‐to‐noise ratio (SNR). However, it can yield further information about the quality of the reconstructed image, and can thus be used to identify and correct image artifacts. While some known approaches try to solve this problem in k‐space, this study addresses it in the spatial domain and uses a modified SENSE reconstruction to reduce or completely remove ghost‐type artifacts arising from processes such as motion or flow during data acquisition. Phantom and in vivo studies show significant improvements in image quality after correction, and serve as a basis for the discussion of the performance and limitations of this new approach. Magn Reson Med, 2005. © 2005 Wiley‐Liss, Inc.