bluuebunny/crossref_metadata_2025 huggingface dataset:
Microwave‐assisted synthesis of a novel phosphorus‐containing spiroorthoester, characterization and cationic polymerization
Authors: Canadell J. , Mantecón A. , Cádiz V.
Published: July 2006

A new phosphorus‐containing spiroorthoester, (1,4,6‐trioxaspiro [4,4] nonan‐2‐yl)‐methyl 3‐[10‐(9,10‐dihydro‐9‐oxa‐9‐phosphaphenanthrene‐10‐oxide)]‐propanoate (SOE‐P), was synthesized under microwave irradiation with a short reaction time (1 h), because classical thermal heating did not lead to the desired product. The structure of the new monomer was confirmed by 1H, 13C, and 31P. SOE‐P was homopolymerized and copolymerized with phenylglycidyl ether with ytterbium triflate as a cationic initiator in DSC experiments. These reactions were monitored by FTIR/ATR, and the formation of poly(ether‐ester)s with a pendant bulky phosphorylated group was shown. © 2006Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4722–4730, 2006
Relationship between the liquid crystallinity and field‐effect‐transistor behavior of fluorene–thiophene‐based conjugated copolymers
Authors: Lim Eunhee , Kim Young Mi , Lee Jeong‐Ik , Jung Byung‐Jun , Cho Nam Sung , Lee Jaemin , Do Lee‐Mi , Shim Hong‐Ku
Published: July 2006

A series of fluorene–thiophene‐based semiconducting materials, poly(9,9′‐dioctylfluorene‐alt‐α,α′‐bisthieno[3,2‐b]thiophene) (F8TT2), poly(9,9′‐di(3,6‐dioxaheptyl)fluorene‐alt‐thieno[3,2‐b]thiophene) (BDOHF8TT), poly(9,9′‐di(3,6‐dioxaheptyl)fluorene‐alt‐bithiophene) (BDOHF8T2), and poly(9,9′‐dioctylfluorene‐co‐bithiophene‐co‐[4‐(2‐ethylhexyloxyl)phenyl]diphenylamine) (F8T2TPA), was synthesized through a palladium‐catalyzed Suzuki coupling reaction. F8TT2, BDOHF8TT, BDOHF8T2, and F8T2TPA films exhibited photoluminescence maxima at 523, 550, 522, and 559 nm, respectively. Solution‐processed field‐effect transistors (FETs) fabricated with all the copolymers except F8T2TPA showed p‐type organic FET characteristics. Studies of the differential scanning calorimetry scans and FETs of the polymers revealed that more crystalline polymers gave better FET device performance. The greater planarity and rigidity of thieno[3,2‐b]thiophene in comparison with bithiophene resulted in higher crystallinity of the polymer backbone, which led to improved FET performance. On the other hand, the random incorporation of the triphenylamine moiety into F8T2TPA caused the polymer chains to lose crystallinity, resulting in an absence of FET characteristics. With this study, we could assess the liquid‐crystallinity dependence of the field‐effect carrier mobility on organic FETs based on liquid‐crystalline copolymers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4709–4721, 2006
Psychosocial factors and patients' preferences for adjuvant chemotherapy in early breast cancer
Authors: Duric Vlatka M. , Butow Phyllis N. , Sharpe Louise , Boyle Frances , Beith Jane , Wilcken Nicholas R.C. , Heritier Stephane , Coates Alan S. , John Simes R. , Stockler Martin R.
Published: July 2006

Purpose: Many women who have had adjuvant chemotherapy for early breast cancer judge small benefits sufficient to make it worthwhile despite significant side effects and inconvenience. The rationality of these preferences has been questioned. We sought to better understand such preferences by assessing associations between preferences and psychosocial factors, and by asking women who judged negligible benefits sufficient to explain why.

Methods: We recruited 83 consecutive consenting women who had completed adjuvant chemotherapy for early breast cancer 3–34 months earlier. Preferences were elicited during a structured, scripted interview using four sets of validated, hypothetical trade‐off scenarios about the possible benefits of adjuvant chemotherapy on survival times (5 and 15 years) and rates (65 and 85% at 5 years). Women completed questionnaires measuring anxiety, depression, optimism, quality and quantity of social support, and illness perceptions.

Results: More than half the women judged benefits of 1 day or 0.1% sufficient to make adjuvant chemotherapy worthwhile. The most important factors in multivariable models were whether the woman had dependants and number of non‐specific symptoms attributed to breast cancer and adjuvant chemotherapy since completing treatment. The proportion of variance explained was modest. Preferences were not associated with: scores for anxiety, optimism, and perceived quality and quantity of social support. Explanations for judging negligible benefits sufficient included minimising regret, parenting concerns, doubts about the information provided and feeling that they had no choice.

Conclusions: Preferences were highly variable and influenced by women's unique circumstances and attitudes, but not by their anxiety or optimism scores. Copyright © 2006 John Wiley & Sons, Ltd.
Electrostatic contribution to the binding stability of protein–protein complexes
Authors: Dong Feng , Zhou Huan‐Xiang
Published: July 2006

To investigate roles of electrostatic interactions in protein binding stability, electrostatic calculations were carried out on a set of 64 mutations over six protein–protein complexes. These mutations alter polar interactions across the interface and were selected for putative dominance of electrostatic contributions to the binding stability. Three protocols of implementing the Poisson‐Boltzmann model were tested. In vdW4 the dielectric boundary between the protein low dielectric and the solvent high dielectric is defined as the protein van der Waals surface and the protein dielectric constant is set to 4. In SE4 and SE20, the dielectric boundary is defined as the surface of the protein interior inaccessible to a 1.4‐Å solvent probe, and the protein dielectric constant is set to 4 and 20, respectively. In line with earlier studies on the barnase–barstar complex, the vdW4 results on the large set of mutations showed the closest agreement with experimental data. The agreement between vdW4 and experiment supports the contention of dominant electrostatic contributions for the mutations, but their differences also suggest van der Waals and hydrophobic contributions. The results presented here will serve as a guide for future refinement in electrostatic calculation and inclusion of nonelectrostatic effects. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Influence of Mn valence bond on ferromagnetic properties of corn‐like Zn1−xMnx O nanorods
Authors: Cong C. J. , Zhang K. L.
Published: July 2006

Corn‐like Zn1−x Mnx O nanorods were synthesized by the rheological phase reaction‐precursor method. X‐ray diffraction analysis reveals that nanocrystalline Zn1−x Mnx O has a wurtzite structure, and the lattice constants of Zn1−x Mnx O increase slightly with increasing Mn2+ contents. Transmission electron microscopy observation shows that the corn‐like Zn1−x Mnx O nanorods consisted of polycrystal nanoparticles, and the diameter of the nanoparticles is about 10–13 nm. The diameter and length of the nanorods are about 150–260 nm and 0.33–1.0 µm, respectively. X‐ray photoelectron spectroscopy measurement indicates that there are different Mn valence bonds in corn‐like Zn1−x Mnx O nanorods. Furthermore, two additional Raman peaks were observed. One peak is considered to have an origin related to the incorporation of Mn ions onto the Zn site of the ZnO lattice; the other may be attributed to the Mn‐based compounds phase. Magnetization measurements under field‐cooling conditions reveal that the Zn1−x Mnx O nanostructures exhibit ferromagnetic behaviors, and both the susceptibility and coercive force of Zn0.95Mn0.05O are larger than that of Zn0.97Mn0.03O and Zn0.93Mn0.07O. The difference of the ferromagnetic properties of Zn1−x Mnx O nanostructures may be attributed to the Mn2+ content. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Survey and mechanism of skin depigmenting and lightening agents
Authors: Parvez Shoukat , Kang Moonkyu , Chung Hwan‐Suck , Cho Chongwoon , Hong Moo‐Chang , Shin Min‐Kyu , Bae Hyunsu
Published: July 2006

The type and amount of melanin synthesized by the melanocyte, and its distribution pattern in the surrounding keratinocytes, determines the actual color of the skin. Melanin forms through a series of oxidative reactions involving the amino acid tyrosine in the presence of the enzyme tyrosinase.

Tyrosinase catalyses three different reactions in the biosynthetic pathway of melanin in melanocytes: the hydroxylation of tyrosine to l‐DOPA and the oxidation of l‐DOPA to dopaquinone; furthermore, in humans, dopaquinone is converted by a series of complex reactions to melanin.

Among the skin‐lightening and depigmenting agents, magnesium‐l‐ascorbyl‐2‐phosphate (MAP), hydroxyanisole, N‐acetyl‐4‐S‐cysteaminylphenol, arbutin (hydroquinone‐beta‐d‐glucopyranoside) and hydroquinone (HQ) are the most widely prescribed worldwide. However, with reports of potential mutagenicity and epidemics of ochronosis, there has been an increasing impetus to find alternative herbal and pharmaceutical depigmenting agents. A review of the literature reveals that numerous other depigmenting or skin‐lightening agents are either in use or in investigational stages. Some of these, such as kojic, glycolic and azelaic acids, are well known to most dermatologists. Others have been discovered and reported in the literature more recently.

Several depigmentation and lightening agents are discussed, including their historical background, biochemical characteristics, type of inhibition and activators from various sources. In addition, the clinical importance of mushroom tyrosinase as a recent prospect is discussed in this paper. Copyright © 2006 John Wiley & Sons, Ltd.
Electrospray ionization tandem mass spectrometry of biphenyl‐modified oligo(deoxy)ribonucleotides
Authors: Tromp Jan M. , Schürch Stefan
Published: July 2006

Antisense oligonucleotides and aptamers are important candidates for future therapeutic applications. Different structural modifications are introduced into oligonucleotides to obtain high affinity and binding specificity. Sequence elucidation of oligonucleotides incorporating a wide variety of modifications presents an analytical challenge, as the standard protocols cannot be applied. Mass spectrometry has the potential to solve complex structural problems. However, a better understanding of the fundamental aspects of gas‐phase dissociation of modified DNA and RNA is needed.

In this work the influence of specific chemical modifications on backbone dissociation is pointed out. Biphenyl‐modified oligo(deoxy)ribonucleotides, which incorporate C‐glycosidic bound abasic nucleobase substitutes, were subjected to collision‐induced dissociation in an electrospray tandem mass spectrometer, with the goal to investigate the role of nucleobase loss on backbone dissociation. DNA bearing biphenyl nucleobase substitutes show abundant [a‐B]‐ and w‐ions generated by cleavage of the 3′‐CO bonds, except for the phosphodiester groups adjacent to the biphenyl modifications. At these positions no dissociation was observed, demonstrating the dependence of DNA backbone dissociation on nucleobase loss. Also, no evidence for a base loss independent mechanism responsible for formation of w‐ions was found. RNA incorporating biphenyl nucleobase substitutes fragment into c‐ and y‐ions resulting from cleavage of the 5′‐PO bond. Adjacent to the biphenyl modifications no altered dissociation behavior was found. This leads to the conclusion that dissociation of RNA is independent of the 1′‐modification and, therefore, independent of nucleobase loss. Copyright © 2006 John Wiley & Sons, Ltd.
Effective solvation of alkaline earth ions by proline‐rich proteolytic peptides of galectin‐3 upon electrospray ionisation
Authors: Lehmann Wolf D. , Wei Junhua , Hung Chien‐Wen , Gabius Hans‐Joachim , Kirsch Dieter , Spengler Bernhard , Kübler Dieter
Published: July 2006

In an analysis of a combined chymotrypsin/AspN digest of galectin‐3 by positive ion nano‐electrospray ionisation mass spectrometry (nanoESI‐MS) several peptides were observed which showed metal adduct ions as their most abundant ion signals. The most prominent adduct ions were observed at m/z values corresponding to [M+40]2+, [M+41]3+, and [M+42]4+ ions. Detailed investigation of the [M+40]2+ ion of the peptide GAPAGPLIVPY showed that it was not, as originally expected, a [M+H+39K]2+ adduct ion but had the composition [M+40Ca]2+. This was verified by several approaches: (i) nanoESI‐MS/MS of the [M+Ca]2+ adduct ions resulted in the virtually exclusive formation of doubly charged fragment ions; (ii) mass determination by quadrupole time‐of‐flight (QTOF)‐MS provided a preliminary identification; and (iii) accurate mass measurement using nanoESI Fourier transform ion cyclotron resonance (FTICR)‐MS at a mass resolving power of 500 000 allowed the specific detection and identification of the isobaric ion pairs [M+40Ca]2+/[M+H+39K]2+ and [M+24Mg]2+/[M+H+23Na]2+. All peptides in the chymotryptic galectin‐3 digest without a basic residue (K or R) showed addition of calcium as the most prominent ionisation principle. A further common feature of these nonbasic peptides was the presence of several proline residues, which is assumed to be a factor promoting the intense addition of calcium. It was observed that the common trace levels of sodium and calcium in analytical grade solvents (about 1–10 µM) are sufficient to generate the [M+H+23Na]2+ and [M+40Ca]2+ ions as the most prominent species of the peptide GAPAGPLIVPY. We conclude that the sequence motifs P‐XX‐P and P‐XXX‐P favour the solvation of alkaline earth ions in ESI‐MS. In view of the successful detection of physiological Ca/protein interactions by ESI‐MS, this finding may point to a solvation of Ca2+ by galectin in solution. The findings open new routes of research in the study of metal/protein and metal/peptide interactions. Copyright © 2006 John Wiley & Sons, Ltd.
Quantitative analyses of β‐carotene and retinol in serum and feces in support of clinical bioavailability studies
Authors: Zhu Dongwei , Wang Yan , Pang Yan , Liu Ang , Guo Jian , Bouwman Carolien A. , West Clive E. , van Breemen Richard B.
Published: July 2006

Among more than 50 provitamin carotenoids, β‐carotene is the most metabolically active source of retinol. Despite diets rich in fruits and vegetables containing β‐carotene, vitamin A deficiency is the leading cause of blindness and childhood mortality in developing countries. In addition, the uncertainty of β‐carotene bioconversion into vitamin A suggests that new data are needed to update the nutritional guidelines in developed countries. Previously, we reported the development of a carotene/retinol plateau isotopic enrichment method (CarRet PIE) for the determination of β‐carotene bioavailability and bioconversion into retinol, which utilizes positive ion atmospheric pressure chemical ionization (APCI) liquid chromatography/mass spectrometry (LC/MS). While seeking to validate the CarRet PIE using a mass balance approach requiring fecal measurements of β‐carotene and retinol, interference was encountered that required substantial modifications of the LC/MS assay. Here we report a new LC/MS assay that is based on the detection of molecular anions of β‐carotene using negative ion APCI with a reversed‐phase C30 column for HPLC separation. Sample preparation required saponification to eliminate interfering triglycerides. The limit of detection (LOD) of β‐carotene was 0.25 pmol calculated on the basis of an injection of 20 µL of 0.0125 µM β‐carotene, and the limit of quantitation (LOQ) was 1.0 pmol based on the injection of 20 µL of 0.050 µM β‐carotene. The linear range was 1.1 to 2179 pmol on‐column. The wide linear range and low LOD and LOQ of this assay facilitated the sensitive and selective quantitative analysis of β‐carotene in both serum and fecal samples in support of an on‐going clinical investigation of β‐carotene bioavailability and bioconversion into vitamin A. Copyright © 2006 John Wiley & Sons, Ltd.
Simultaneous determination of isoflavones and lignans at trace levels in natural waters and wastewater samples using liquid chromatography/electrospray ionization ion trap mass spectrometry
Authors: Kang Jinguo , Price William E. , Hick Larry A.
Published: July 2006

A high‐performance liquid chromatography/electrospray ionization ion trap mass spectrometry (HPLC/ESI‐MSn) method has been developed for the trace determination of phytoestrogens in aquatic environmental samples. The method includes solid‐phase extraction (SPE) and analysis using liquid chromatography/electrospray ionization ion trap mass spectrometry. The aquatic environmental samples, influent of a wastewater treatment plant (WWTP) and creek water, were adjusted to pH ∼5 before extraction. The analyzed phytoestrogens were identified by an MSn method and quantified against a deuterated internal standard (genistein‐3′,5′,6,8‐D4). In negative ion mode, 0.1% formic acid was employed in acetonitrile/water mobile phase. The method detection limits ranged from 0.5 to 10 ng/L in WWTP influent and from 0.1 to 5 ng/L in creek water. Average SPE recoveries for the analyzed phytoestrogens ranged from 85 to 95%, with a relative standard deviation (RSD) (%) ranging from 3.9 to 6.5. The concentrations of the six analyzed phytoestrogens varied from 0.2 to 600 ng/L with high levels of enterolignans (enterolactone and enterodiol) found in the collected wastewater. The method is shown to be suitable for the determination of phytoestrogens in aquatic environmental samples at nano‐ and sub‐nanogram per liter levels. Copyright © 2006 John Wiley & Sons, Ltd.
Covering the Percutaneous Endoscopic Gastrostomy (PEG) Tube Prevents Peristomal Infection
Authors: Suzuki Yutaka , Urashima Mitsuyoshi , Ishibashi Yoshio , Abo Masahiro , Mashiko Hiroshi , Eda Yukimoto , Kusakabe Toshiro , Kawasaki Naruo , Yanaga Katsuhiko
Published: July 2006

Background

Because oropharyngeal bacteria can be brought through the abdominal wall during percutaneous endoscopic gastrostomy (PEG), peristomal infection is one of the most frequent complications in patients who undergo the procedure. This study aimed to determine whether covering the PEG tube with a sheath that could be detached in the stomach could help prevent peristomal infection.

Methods

In three community hospitals in Japan, data from 449 patients with swallowing dysfunction were prospectively collected between March 2000 and February 2002 for non‐covered PEG (n = 206) and between March 2002 and February 2004 for covered PEG (n = 243).

Results

After adjusting for hospital, age, gender, and underlying diseases, covering the PEG significantly reduced peristomal purulent infection compared with non‐covered PEG (odds ratio: 0.05; 95% confidence interval: 0.02–0.13). Body temperature, white blood cell count, and C‐reactive protein at day 3 after PEG placement, as well as duration of antibiotics usage, were significantly lower or shorter in patients treated with covered PEG than non‐covered PEG. In spite of the same frequencies in the two groups of methicillin‐resistant Staphylococcus aureus and Pseudomonas aeruginosa in oropharyngeal cultures before PEG placement, these organisms were detected significantly less frequently in peristomal lesions of patients who underwent covered PEG. Moreover, 28 patients treated with covered PEG received no antibiotic therapy, and 27 of them had no signs of peristomal infection.

Conclusions

These results suggest that covering the PEG tube, with or without providing antibiotic therapy, may prevent peristomal infection in spite of the presence of oropharyngeal bacterial flora after percutaneous endoscopic gastrostomy.
Exact Interval Estimation, Power Calculation, and Sample Size Determination in Normal Correlation Analysis
Authors: Shieh Gwowen
Published: July 2006

This paper considers the problem of analysis of correlation coefficients from a multivariate normal population. A unified theorem is derived for the regression model with normally distributed explanatory variables and the general results are employed to provide useful expressions for the distributions of simple, multiple, and partial-multiple correlation coefficients. The inversion principle and monotonicity property of the proposed formulations are used to describe alternative approaches to the exact interval estimation, power calculation, and sample size determination for correlation coefficients.
The Nature of Climate and Climatic Variations
Authors: Kutzbach John E.
Published: July 2006

The climate system consists of the atmosphere, the oceans, the cryosphere (land ice, snow, sea ice), the lithosphere, and the biomass. The behavior of the individual components of the system is governed by processes occurring over a broad range of time and space scales. The components are coupled by physical, biological, and chemical processes, and the coupled system seems capable of undergoing fluctuations on all time scales. In addition to these “internal” climatic processes, external processes (such as variability in the solar irradiance or human activities) must also be considered. Space and time scales of climatic variability are reviewed, with emphasis on the Holocene. Regional patterns of climatic variability may be associated with changes in the amplitude and longitudinal position of the long waves in the westerlies of midlatitudes, and with changes in the intensity and latitude of meridional circulation features such as the Hadley cell. Possible examples of this are mentioned. The variance spectrum of climatic time series is described and certain implications for climate modeling are suggested.
Physical Evidence of Quaternary Climatic Change
Authors: Flint Richard Foster
Published: July 2006

Changes of climate have characterized parts, and at times apparently all, of Earth's surface. Changes that have occurred during the Quaternary period have special significance because, being comparatively recent, they are revealed by physical geologic features that are still at or near the surface, as yet little damaged by erosion. Although some of these features can be interpreted in terms that are broadly quantitative, most are still only qualitative in that they are limited to specifying climatic parameters that are positive or negative relative to those prevailing today in the same area. The common parameters indicated by the physical evidence include temperature (mean annual or summer) and precipitation (mean annual or seasonal). More rarely directions and minimum speeds of effective winds can be specified. A useful basis for reconstructions of former climates is a checklist of the relict geologic features from which climatic inferences can be drawn. Such a list is given here.
Continental Ice Sheets and the Planetary Radiation Budget
Authors: Oerlemans J.
Published: July 2006

The interaction between continential ice sheets and the planetary radiation budget is potentially important in climate-sensitivity studies. A simple ice-sheet model incorporated in an energybalance climate model provides a tool for studying this interaction in a quantitative way. Experiments in which the ice-sheet model is coupled step by step to the climate model show that ice sheets hardly affect the zonal mean radiation balance because the albedo feedback due to sea ice and snow cover is dominating. The model requires a 5% drop in the solar constant to create ice sheets of ice-age size.

If the feedback between surface elevation and ice-mass balance is included (in a very crude way), the ice-sheet size (L, measured southward from 70°N) becomes much more sensitive to in insolation. For a range of normalized solar constants, roughly from 0.98 to 1.02, two stable solutions exist: L ⋍ 0 and L ⋍ 2000 km. This result demonstrates that the response of ice sheets to insolation variations is far from linear. It also stresses the need for explicit modeling of the ice-mass balance of ice sheets, particularly its dependence on surface elevation.
A Paleoclimate Model of Northern Hemisphere Ice Sheets
Authors: Birchfield G.E. , Weertman Johannes , Lunde Albert T.
Published: July 2006

A model for predicting the growth and decay of ice sheets based on the astronomical theory of climate change is presented. The purpose of the study in part is to isolate the role of the ice-sheet physics and earth response under varying ice load by simplifying to the extreme the role of the hydrosphere-atmosphere. Ice sheet physics and the response of the lithosphere-asthenosphere under the ice load are modeled explicitly. Insolation anomalies (taken at a fixed latitude) directly force latitudinal displacement of the snow line. Accumulation rate a, and ablation rate a′ evaluated at mean sea level are specificed as external constants; a,a′ decrease linearly with ice sheet elevation. Rough tuning of the model to the general shape of the ice-volume record of the last two major glacials determines the external constants. Model predictions of the ages of several events in the last major glaciation compare well with the radiological ages. The six glacial terminatios (I–VI) over the last 600,000 yr are identified and the predicted ages compare reasonably well with the δ18O record for two deep-sea cores. A direct comparison of model power spectra of ice volume as a function of period with spectra of the δ18O record shows apparent underprediction of power near 100,000 yr. When a quantitative but heuristic method for taking into account the “red noise” spectrum evident in the geological records is used, a much more favorable comparison is possible. The model prediction lends support to the hypothesis that the nonlinearity of the ice-sheet physics is responsible for the 100,000-yr periodicity in the geological record of the late Pleistocene.
Correlation Between Long-Term Pedogenic CaCO3 Formation Rate and Modern Precipitation in Deserts of the American Southwest
Authors: Marion Giles M.
Published: July 2006

The rates of CaCO3 formation in desert soils of the American Southwest are highly variable and potentially useful in estimating the age of soil profiles. The objective of this study was to examine the correlation between the long-term rate of CaCO3 formation (LTR) and modern mean annual precipitation (MAP) and temperature (MAT). LTR is not significantly related to temperature but is linearly related to MAP [LTR = 0.0150(MAP − 37), r2 = 0.924]. The slope of the regression is significantly different from 0.0 and is equivalent to a calcium concentration of 6.0 mg liter−1 in rainfall. However, the intercept term, which suggests a lower limit of precipitation for CaCO3 formation of 37 mm, is not significantly different from 0.0. The LTR-MAP relationship may be useful in estimating the age of soil profiles by the CaCO3 method in the desert Southwest.
Stratigraphy and Paleoecology of Pleistocene Interstadial Sediments, Central British Columbia
Authors: Clague John J. , Hebda Richard J. , Mathewes Rolf W.
Published: July 2006

Two exposures of organic-rich interstadial sediments in central British Columbia provide information on middle Wisconsinan environments and climates near the center of the region subsequently covered by the late Wisconsinan Cordilleran Ice Sheet. Interstadial sediments at Bullion Pit overlie drift of early Wisconsinan or older age and underlie thick drift of late Wisconsinan age. Alluvium (or colluvium) and peat were deposited on the floor of the ancestral Quesnel River valley 46,000–40,000 14C yr ago when the vegetation consisted of spruce forest with dry openings and local fens and the climate was colder and perhaps drier than today. This is broadly consistent with paleoclimatic reconstructions for the same time interval for Babine Lake, 400 km to the northwest, and for Meadow Creek, 400 km to the southeast. Plant-rich pond sediments containing tephra layers and vertebrate remains are exposed between two drifts in a ravine at Mexican Hill, 30 km east of Quesnel. Although they may be contemporaneous with the Bullion Pit beds, the nonglacial sediments at Mexican Hill more likely were deposited sometime after the warmest part of the last interglaciation, but prior to 50,000 yr B.P. At that time, the vegetation at Mexican Hill probably was parkland. The present vegetation at Mexican Hill is boreal forest; thus, a drier and possibly cooler climate is indicated.
Lake evolution during the past 30,000 years in China, and its implications for environmental change
Authors: Fang Jin-qi
Published: July 2006

Throughout China over the last 30,000 years high lake levels were reached during 30,000–24,000, 22,500-20,000, and 9500-3500 yr B.P. Lake recovery after the last glacial maximum (LGM) apparently was much slower, and involved stronger regional differences, than was lake regression during the onset of the last glaciation. According to the character of lake development during the last 18,000 years, three regions and six subregions have been distinguished. In the Tibetan Plateau and alpine regions of western China the plentiful supply of meltwater may have caused lakes to recover and reach their highest levels fust after the LGM. Lake hydrology in central and northern China was directly controlled by rainfall and evaporation, and most lakes reached their highest levels between 9500 and 3500 yr B.P. In the lowlands of eastern China lake recovery was closely tied with channel aggradation and water level rise of rivers, which are associated with Holocene sea level rise and human agricultural activities. Most lakes recovered and were most extensive in the middle and late Holocene.
Thermoluminescence and Excess 226Ra Decay Dating of Late Quaternary Fluvial Sands, East Alligator River, Australia
Authors: Murray Andrew , Wohl Ellen , East Jon
Published: July 2006

Thermoluminescence (TL) dating was applied to seven samples of siliceous fluvial sands from the East Alligator River of Northern Australia, giving ages ranging from modern to 6000 yr B.P. Two methods of estimating the equivalent dose (ED), total bleach and regenerative, were applied to the 90- to 125-μm quartz fraction of the samples in order to determine the reliability and internal consistency of the technique. High-resolution γ and α spectroscopy were used to measure radionuclide contents; these measurements revealed an excess 226Ra activity compared with 230Th. This excess decreased with depth, and was used directly to derive mean sedimentation rates, and thus sediment ages. Both this method and one 14C date confirmed the validity of the TL values, which increased systematically with depth and were consistent with site stratigraphy. TL was of limited use in the dating of these late Holocene deposits because of age uncertainties of 500 to 1600 yr, resulting from a significant residual ED. This residual probably resulted from incomplete bleaching during reworking upstream of the sampling site. For Pleistocene deposits, the residual ED will be less significant because of higher total EDs, and TL dates will be correspondingly more accurate.
The Last Glacial Maximum on Spitsbergen, Svalbard
Authors: Mangerud Jan , Bolstad Magne , Elgersma Anne , Helliksen Dag , Landvik Jon Y. , Lønne Ida , Lycke Anne Katrine , Salvigsen Otto , Sandahl Tom , Svendsen John Inge
Published: July 2006

Most scientists have concluded previously that the west coast of Spitsbergen, Svalbard, remained ice-free during the late Weichselian, between 25,000 and 10,000 yr B.P. We conclude that the glaciation was more extensive. Terraces that were postulated to have been ice-free are covered by a thin, late Weichselian till. Sudden drop in the marine limit and basal radiocarbon dates of raised glaciomarine sediments demonstrates that the glaciers in the main fjords, Isfjorden and Van Mijenfjorden, terminated west (outside) of the fjord mouths. Basal radiocarbon dates from glaciomarine clay above till in cores from the continental shelf west of Spitsbergen yielded ages of about 12,500 yr B.P., from which we conclude that the ice extended to the shelf edge. Based on the extent of amino acid diagenesis in radiocarbon-dated molluscs, the duration of the maximum extension of the late Weichselian glaciation was short, certainly less than 10,000 years. During the ice-free period preceding that glaciation, at least back to 40,000 yr B.P., the glaciers on Svalbard were not significantly larger than at present, as shown by marine deposits close to the glacier snouts. Many radiocarbon dates place deglaciation of the outer coast at about 12,500 yr B.P. At about 10,000 yr B.P., the rest of the archipelago rapidly became ice-free.
Patterns of Holocene Climatic Change in the Midwestern United States
Authors: Wright H. E.
Published: July 2006

The Holocene pollen sequence in the Minnesota area is “asymmetric” around the so-called prairie period: the early Holocene is dominated by elm (with pine in the north) and the late Holocene by oak. The elm zone is interpreted as a manifestation of summer monsoonal rains enhanced by the Milankovitch insolation maximum, and the pine in the north is interpreted as a result of summer cooling near the retreating ice sheet. As the summer insolation waned during the Holocene, its associated monsoonal rains from the Caribbean moisture source lasted longer in the south (northeastern Iowa and southern Wisconsin), where the inferred mesic elm forest changed to prairie as late as 5000 yr B.P., compared to 8000 yr. B.P. in Minnesota (and 9000 yr B.P. in the Dakotas).
FROM LONG-TERM PATTERNS OF SEASONAL HUNGER TO CHANGING EXPERIENCES OF EVERYDAY POVERTY: NORTHEASTERN GHANA C. 1930–2000
Authors: DESTOMBES JÉRÔME
Published: July 2006

This article is a West African case-study of the nutritional history of everyday poverty. It draws on unusually rich statistical evidence collected in northeastern Ghana. In the 1930s, pioneer colonial surveys revealed that seasonal poor diet was pervasive, by contrast with undernourishment. They pave the way for constructing a new set of anthropometric data in Nangodi, a savanna polity where John Hunter completed a classic study of seasonal hunger in the 1960s. A re-survey of the same sections and lineages c. 2000, during a full agricultural cycle, shows a significant improvement in nutritional statuses, notably for women.
‘SEA KAFFIRS’: ‘AMERICAN NEGROES’ AND THE GOSPEL OF GARVEYISM IN EARLY TWENTIETH-CENTURY CAPE TOWN
Authors: VINSON ROBERT TRENT
Published: July 2006

This article demonstrates that black British West Indians and black South Africans in post-First World War Cape Town viewed ‘American Negroes’ as divinely ordained liberators from South African white supremacy. These South-African based Garveyites articulated a prophetic Garveyist Christianity that provided common ideological ground for Africans and diasporic blacks through leading black South African organizations like the Universal Negro Improvement Association and African Communities League (UNIA), the African National Congress (ANC) and the Industrial and Commercial Workers Union (ICU). This study utilizes a ‘homeland and diaspora’ model that simultaneously offers an expansive framework for African history, redresses the relative neglect of Africa and Africans in African diaspora studies and demonstrates the impact of Garveyism on the country's interwar black freedom struggle.
BODY, POWER AND SACRIFICE IN EQUATORIAL AFRICA
Authors: BERNAULT FLORENCE
Published: July 2006

This article revisits the trope of the traffic in body parts in colonial and postcolonial Equatorial Africa. Current analyses, mostly written by anthropologists and sociologists, explain these rumors by the destructive integration of Africa in the world's economy and the commodification of the human body. While acknowledging their fertility, I argue that these approaches fail to understand how, during the colonial era, Europeans and Africans participated in the re-enchanting of the human body. The first part of the article examines Equatorial African conceptions of the body as central in the crafting of power and social reproduction, and reconstructs how these views were disturbed by colonial intrusion. The second part turns to European discourses and suggests that the colonial situation revealed significant contradictions in the western fiction of a modern disconnect between the body and power. The series of political and moral transgressions triggered by the conquest made apparent how Europeans themselves envisioned political survival as a form of positive exchange revolving around the body-fetish. The third section puts these ideas to the test of funeral practices to show how, in the colony, black and white bodies became re-sacralized as political resources. Building on these findings, the conclusion questions anthropologists' and historians' tendency to draw epistemic boundaries between western and African imaginaries.
African Urban Spaces in Historical Perspective. Edited by STEVENJ.SALM and TOYINFALOLA. Rochester NY: University of Rochester Press, 2005. Pp. xl+395. £50/$75 (ISBN 1-58046-163-8). Urbanization and African Cultures. Edited by TOYINFALOLA and STEVENJ.SALM. Durham NC: Carolina Academic Press, 2005. Pp. xv+464. $45, paperback (ISBN 0-89089-558-9).
Authors: BURTON ANDREW
Published: July 2006

The profile of African urban history has risen considerably of late, with the appearance of a number of important monographs and edited collections. What is more, with the plethora of younger scholars as well as more established historians now exploring Africa's urban pasts, its profile is set to rise further. African Urban Spaces in Historical Perspective represents the latest contribution to this emerging sub-field. A companion volume, Urbanization and African Cultures, is of a more interdisciplinary character. Both are drawn from contributions to a 2003 University of Texas conference.

African Urban Spaces will be of more interest to readers of this journal, not only because of its historical focus but also its higher quality and greater cohesion. It covers an impressive geographical and temporal range, with chapters on primary and secondary cities throughout Africa, spanning the precolonial past to the present. It is introduced by one of the pioneers of Africa's urban history, Catherine Coquery-Vidrovitch, who teases themes from the collection and signals promising avenues for future research. However, poor referencing mars the introduction, a symptom of the apparently loose editorial role exercised over the book as a whole. Greater intervention could have strengthened the collection considerably: not only to ensure consistent referencing (authors variously adopt endnotes and social science/intratext systems) and to minimize typographical errors, but more seriously to tighten the sloppier passages and chapters. The quality of the chapters varies considerably, some representing useful scholarly contributions, others being pedestrian accounts offering little or nothing new.
Rescates and Anglo-Spanish Trade in the Caribbean during the French Revolutionary Wars, ca. 1797–1804
Authors: PEARCE ADRIAN J.
Published: July 2006

Rescates (ransoms) consisted of the repurchase by Spanish and Spanish American merchants of ships and cargoes taken as prizes during wartime and sold in the British West Indies. This is the first detailed study of the subject, drawing on archives in Britain, Spain and the Americas. It is argued that rescates typified a broader range of legal ruses designed to protect Anglo-Spanish trade in the Americas from both wartime disruption and customs interference. As a mechanism for the legal protection of commerce promoted by both the British and the Spaniards, rescates enjoyed considerable success during the war that commenced in 1796, especially with respect to trade between the British ports in the Caribbean, Cuba and Mexico. They thus played a key role in the strong and sustained growth which characterised trade between the British and Spanish empires during these years.
Computational biology in the study of cardiac ion channels and cell electrophysiology
Authors: Rudy Yoram , Silva Jonathan R.
Published: July 2006

1. Prologue 58

2. The Hodgkin–Huxley formalism for computing the action potential 59

2.1 The axon action potential model 59

2.2 Cardiac action potential models 62

3. Ion-channel based formulation of the action potential 65

3.1 Ion-channel structure 65

3.2 Markov models of ion-channel kinetics 66

3.3 Role of selected ion channels in rate dependence of the cardiac action potential 71

3.4 Physiological implications of IKs subunit interaction 77

3.5 Mechanism of cardiac action potential rate-adaptation is species dependent 78

4. Simulating ion-channel mutations and their electrophysiological consequences 81

4.1 Mutations in SCN5A, the gene that encodes the cardiac sodium channel 82

4.1.1 The ΔKPQ mutation and LQT3 82

4.1.2 SCN5A mutation that underlies a dual phenotype 87

4.2 Mutations in HERG, the gene that encodes IKr: re-examination of the ‘gain of function/loss of function’ concept 94

4.3 Role of IKs as ‘repolarization reserve’ 100

5. Modeling cell signaling in electrophysiology 102

5.1 CaMKII regulation of the Ca2+ transient 102

5.2 The β-adrenergic signaling cascade 105

6. Epilogue 107

7. Acknowledgments 108

8. References 109

The cardiac cell is a complex biological system where various processes interact to generate electrical excitation (the action potential, AP) and contraction. During AP generation, membrane ion channels interact nonlinearly with dynamically changing ionic concentrations and varying transmembrane voltage, and are subject to regulatory processes. In recent years, a large body of knowledge has accumulated on the molecular structure of cardiac ion channels, their function, and their modification by genetic mutations that are associated with cardiac arrhythmias and sudden death. However, ion channels are typically studied in isolation (in expression systems or isolated membrane patches), away from the physiological environment of the cell where they interact to generate the AP. A major challenge remains the integration of ion-channel properties into the functioning, complex and highly interactive cell system, with the objective to relate molecular-level processes and their modification by disease to whole-cell function and clinical phenotype. In this article we describe how computational biology can be used to achieve such integration. We explain how mathematical (Markov) models of ion-channel kinetics are incorporated into integrated models of cardiac cells to compute the AP. We provide examples of mathematical (computer) simulations of physiological and pathological phenomena, including AP adaptation to changes in heart rate, genetic mutations in SCN5A and HERG genes that are associated with fatal cardiac arrhythmias, and effects of the CaMKII regulatory pathway and β-adrenergic cascade on the cell electrophysiological function.
In Search of Soviet Salvation: Young People Write to the Stalinist Authorities
Authors: FÜRST JULIANE
Published: July 2006

Letters have always been an important medium between rulers and subjects in the Soviet Union and Russia. This article looks at letters from young people to Soviet party officials, newspapers and youth organizations, using them as texts in their own right rather than as sources for the events they describe. A close and detailed analysis of the letters' language, structure and style reveals the subjective universe of their authors and the function of letters both in the personal life of their writers and in the Soviet system overall. Particular attention is paid to letters that employ confessionary narratives. The eschatological trajectory of other Soviet autobiographical texts, which chart the inevitable progress from an unenlightened state to ideological conviction, is reversed in these letters, leading the reader from a happy Soviet life to a point of confusion and ideological doubt. While the crises, which are at the heart of these letters, reveal the difficulties of young people in making sense of the Soviet world around them, they also demonstrate the extent to which young people's norms, values and language were infused by Bolshevik thought. The process of letter writing was thus both an affirmation of the system and a testimony to its failings.
Surface Microanalysis with Slow Electrons
Authors: Bauer Ernst G.
Published: July 2006

Microanalysis on the 10-nm level using imaging, diffraction, and spectroscopy of slow photo-emitted and reflected electrons is discussed. The instrumentation that uses a cathode lens is briefly reviewed, and a number of applications illustrate the power of this microanalysis method.
AES Studies on the Ti/N Compositionally Gradient Film Deposited
onto Ti-6Al-4V Alloy by Reactive DC Sputtering
Authors: Sonoda Tsutomu , Watazu Akira , Katou Kiyotaka , Asahina Tadashi
Published: July 2006

Deposition of Ti/N compositionally gradient film onto Ti-6Al-4V
alloy substrates was carried out by reactive DC sputtering, not only to
improve the blood compatibility of the alloy but also to relax the stress
concentrated at the interface between the film and the alloy substrate.
The compositional gradient was realized by varying continuously the
nitrogen content in Ar-N2 sputter gas during deposition. In
Auger electron spectroscopy (AES) analysis, Auger spectra were acquired in
the N(E) mode using the beam brightness modulation (BBM) method to
overcome the problem of the peak overlap of the principal Auger nitrogen
transition peak (N-KLL) with one of titanium peaks (Ti-LMM). The deposited
film appeared to be uniform and adhesive. TiN formation at the surface of
the film was assumed, because of its yellow gold color and the X-ray
diffraction (XRD) pattern for it. Under scanning electron microscopy, it
was found that the surface had fine particles dispersed on a smooth
accumulated deposit and that this depositing method improved the
structural property of the film at the surface. According to AES in-depth
profiles, the nitrogen (N) concentration in the film gradually decreased
in the depth direction from the surface toward the alloy, confirming that
a Ti/N compositionally gradient film had formed on the alloy
substrate.
Introduction: Selected Papers from the EMAS–IUMAS Workshop in Florence, Italy
Authors: Rinaldi Romano
Published: July 2006

This issue of Microscopy and Microanalysis presents nine of
the articles from the 9th Workshop of the European Microbeam Analysis
Society (EMAS) on “Modern Developments and Applications in Microbeam
Analysis” held in conjunction with the 3rd Meeting of the
International Union of Microbeam Analysis Societies (IUMAS) in Florence,
Italy, on May 22–26, 2005.
Editorial
Authors:   WTE/JWS
Published: July 2006

COURT, MEET THY PUBLIC

The public stir caused by recent rulings of the European Court of Justice opens a new window on the EU judiciary's condition and especially on its relations with the public. In the Pupino judgment, the Court ordered Italian colleagues to align domestic rules of criminal procedure with the EU ones by way of construction, whenever possible. The Environmental Framework decision ruling was about a legislative act meant to have states protect the environment by the use of criminal sanctions.
Nomination of Constitutional Justices in Post-Communist Countries: Trial, Error, Conflict in the Czech Republic
Authors: Kühn Zdeněk , Kysela Jan
Published: July 2006

Selection and nomination of constitutional justices – American model of judicial review in post-communist countries – Tensions between parliamentary supremacy and excessive activism of Constitutional Courts – Possibility of reappointment and the independence of justices – Lack of cooperation between President and Senate in the Czech Republic – Politicization of judicial nomination and democracy.
The Composite Case for National Parliaments in the European Union: Who Profits from Enhanced Involvement
Authors: Kiiver Philipp
Published: July 2006

National parliaments near-universally endorsed in the European Union constitution-building process – Case for national parliaments a composite one: different scholarly approaches and national and European institutions support a greater role for national parliaments for different reasons – The overall endorsement of national parliaments remains a balancing act between competing agendas – Future reforms and treaty-drafting efforts most likely will continue to favour approaches of open-ended political content – No risk for the national governments nor Union institutions.