bluuebunny/crossref_metadata_2025 huggingface dataset:
A Stochastic Model for Cancer Risk
Authors: Schinazi Rinaldo B
Published: July 2006

We propose a simple stochastic model based on the two successive mutations hypothesis to compute cancer risks. Assume that only stem cells are susceptible to the first mutation and that there are a total of D stem cell divisions over the lifetime of the tissue with a first mutation probability μ1 per division. Our model predicts that cancer risk will be low if m = μ1D is low even in the case of very advantageous mutations. Moreover, if μ1D is low the mutation probability of the second mutation is practically irrelevant to the cancer risk. These results are in contrast with existing models but in agreement with a conjecture of Cairns. In the case where m is large our model predicts that the cancer risk depends crucially on whether the first mutation is advantageous or not. A disadvantageous or neutral mutation makes the risk of cancer drop dramatically.
The Effect of Preoperative Use of an Orthopedic Plate on Articulatory Function in Children with Cleft Lip and Palate
Authors: Suzuki Keiko , Yamazaki Yasuharu , Sezaki Kouichiro , Nakakita Nobuaki
Published: July 2006

Objective

To evaluate the effect of preoperative use of an orthopedic plate (OP) on postoperative articulatory function in children with cleft lip and palate.

Subjects

The subjects had complete unilateral or bilateral cleft lip and palate and were scheduled for a one-stage palatoplasty.

Main Outcome Measures

Tongue movements during sucking were analyzed by ultrasonography. Postoperative articulatory behavior was also assessed at 5 years 4 months of age.

Results

There was an excessive downward excursion of the rear portion of the tongue during sucking regardless of the use or nonuse of the OP. This indicated that infants with cleft palate could not create negative pressure in the oral cavity, even with the OP. However, the OP appeared effective for preventing irregular movements of the tongue during sucking. The proportion of subjects obtaining excellent articulation was significantly higher in the group using the OP until palatoplasty than in the group who did not continue using the OP. The proportion of subjects with disturbed articulatory function in the latter group was comparable with that in the control group, who never used the OP.

Conclusions

Continuous use of the OP up to the time of palatoplasty appeared to be effective for the postoperative articulatory function in children with complete cleft lip and palate. Inhibiting irregular movements of the tongue, the OP might assist in preventing “palatalized articulation.”
Facile Synthesis of a Monosulfonated Triphenylphosphane (TPPMS) Derived Ligand having Strong π‐Acceptor Character
Authors: Gulyás Henrik , Bacsik Zoltán , Szöllősy Áron , Bakos József
Published: July 2006

Two phenyl rings of triphenylphosphane have been modified by electron‐withdrawing trifluoromethyl groups. A methoxy group has been introduced at the para‐position of the third ring. Due to the activating effect of the methoxy group, the phosphane can be monosulfonated under mild conditions and with complete selectivity. The novel ligand, sodium 5‐[bis‐(4‐trifluoromethylphenyl)phosphanyl]‐2‐methoxybenzenesulfonate, has been obtained in quantitative yield, and it has an outstanding π‐acceptor capacity among the known sulfonated triarylphosphanes. It is not soluble in water but soluble in light alcohols and ionic liquids. Its solubility properties allow facile catalyst separation without water.
A Rapid and Reliable Assay for Regioselectivity Using Fluorescence Spectroscopy
Authors: Angelovski Goran , Keränen Mark D. , Linnepe Petra , Grudzielanek Stefan , Eilbracht Peter
Published: July 2006

The first report of a fluorescence‐based assay for the direct measurement of the regioselectivity of a reaction is described herein, developed from the desire to construct a quicker analytical method for the determination of the ratio of regioisomers obtained in the tandem hydroformylation/Fischer indole synthesis. The method allows for extremely rapid acquisition times, as the use of crude reaction mixtures is allowed. The assay is also shown to be overall very reliable, tolerating the presence of various functional groups and proceeding on average with a standard error of measurement comparable to that of NMR. As fluorescence is the only requirement for the employment of this analytical method, countless numbers of target‐specific assays can undoubtedly be developed based upon this initial finding.
Potassium Fluoride/Basic Alumina as Far Superior Heterogeneous Catalyst for the Chemoselective Conjugate Addition of Nitroalkanes to Electron‐Poor Alkenes Having Two Electron‐Withdrawing Groups in α‐ and β‐Positions
Authors: Ballini Roberto , Palmieri Alessandro
Published: July 2006

The chemoselective, conjugate addition of nitroalkanes to electron‐poor alkenes, with two electron‐withdrawing groups in the α‐ and β‐positions, can be easily performed at room temperature under solventless conditions using potassium fluoride/basic alumina as heterogeneous catalyst.
Rh and ABO maternal‐fetal incompatibility and risk of autism
Authors: Zandi Peter P. , Kalaydjian Amanda , Avramopoulos Dimitrios , Shao Huibo , Fallin M. Daniele , Newschaffer Craig J.
Published: July 2006

We hypothesized that maternal‐fetal incompatibility at the Rh or ABO loci may contribute to the risk of autism. There are biologically plausible reasons to believe such effects may play a role, and two previous epidemiologic studies have provided suggestive evidence. To further test this hypothesis, we genotyped the Rh and ABO loci in a sample of 389 independent case‐parent trios from the AGRE repository and analyzed the data using a modification of the log‐linear model for case‐parent trios in which the effects of maternal‐fetal genotype incompatibility are modeled jointly with the effects of the affected child's or mother's genotypes. We did not find any evidence that incompatibility at the Rh or ABO loci increases the risk of autism. Furthermore, we did not find any evidence for the presence of a high‐risk susceptibility allele at or near these two loci operating either through the mother or child. © 2006 Wiley‐Liss, Inc.
Effect of starvation on insulin production and insulin binding in Tetrahymena
Authors: Csaba G. , Kovács P. , Pállinger Éva
Published: July 2006

Tetrahymena pyriformis GL was starved for 24 h and then the immunologically demonstrable insulin content and FITC‐insulin binding were measured by flow cytometry and localization was studied by confocal microscopy. The amount of endogeneous insulin as well as FITC insulin binding, was highly significantly elevated. Glucose feeding for 30 min abolished the elevation of FITC‐insulin binding. In starved cells, insulin‐binding sites disappeared from the surface and FITC‐insulin was bound inside the cells, within large food vacuoles. Endogeneous insulin was dispersed in the cytoplasm both in the control and starved cells and food vacuoles did not contain it. The results call attention to the stimulatory effect of starvation on insulin production in Tetrahymena, in parallel with the internal storage of insulin receptors, which points to an autocrine mechanism. Copyright © 2006 John Wiley & Sons, Ltd.
Alpha‐tocopherol, beta‐carotene and melatonin administration protects cyclophosphamide‐induced oxidative damage to bladder tissue in rats
Authors: Sadir Serdar , Deveci Salih , Korkmaz Ahmet , Oter Sukru
Published: July 2006

Cyclophosphamide (CP) has potential urotoxicity such as hemorrhagic cystitis (HC). 2‐Mercaptoethane sulfonate (mesna) has been widely used as an effective agent against CP‐induced cystitis, but significant HC has still been encountered clinically. In recent studies, mesna was shown to be more effective if combined with antioxidants. The purpose of this study was to evaluate the effects of antioxidants, α‐tocopherol, β‐carotene and melatonin on CP‐induced bladder damage in rats, even if used without mesna administration. Male Spraque–Dawley rats weighing 180–210 g were divided into 5 groups. Four groups received a single dose of CP (100 mg/kg) intraperitoneally with the same time intervals. Group 2 received CP only, group 3 received β‐carotene (40 mg/kg/day), group 4 received α‐tocopherol (40 mg/kg/day) and group 5 received melatonin (10 mg/kg/day) both before and the day after CP injection. Group 1 served as control. Bladder histopathology, as well as malondialdehyde (MDA) and iNOS levels, and excretion of nitrite‐nitrates (NOx) in urine were evaluated. CP injection resulted in severe histological changes and macroscopic hematuria. α‐Tocopherol and melatonin showed meaningful protection against bladder damage. Protection by β‐carotene was also significant but weaker. MDA levels increased significantly with CP injection and all antioxidants ameliorated this increase in bladder tissue. CP also elevated the NOx level in urine and iNOS activity in bladder. Only melatonin was able to decrease these parameters. In conclusion, there is no doubt that oxidants have a role in the pathogenesis of CP‐cystitis. Antioxidants, especially melatonin and α‐tocopherol, may help to ameliorate bladder damage induced by CP. Copyright © 2006 John Wiley & Sons, Ltd.
VCD spectroscopic investigation of enantiopure cyclic β‐lactams obtained through lipolase‐catalyzed enantioselective ring‐opening reaction
Authors: Vass Elemér , Hollósi Miklós , Forró Enikő , Fülöp Ferenc
Published: July 2006

A direct enzymatic method for the preparation of cyclic β‐lactams and β‐amino acids was recently developed, involving the Lipolase‐catalyzed enantioselective hydrolysis of racemic β‐lactams in an organic solvent. Vibrational circular dichroism (VCD) spectroscopy combined with quantum chemical calculations at ab initio (DFT) level of theory has now been applied to determine the absolute configuration and conformation of a series of cyclic β‐lactams (1–10). The absolute configuration of 8 was derived from X‐ray crystallography. Only indirect evidence was available for 1, 2, 5, 6, and 7. The absolute configuration of the new lactams 3, 4, 9, and 10 was not known previously. The VCD analysis indicated the homochirality of the studied lactams. The conformation of the flexible β‐lactams was also predicted from the VCD data. Even in the cases where multiple conformers are allowed, the predominance of one conformer was found, with the exception of 2, being present as a mixture of four conformers. β‐Lactams tend to form H‐bonded dimers. The fine structure of the amide I VCD band suggested that only a small population of H‐bonded dimers is formed in deuterated chloroform. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Cytoarchitecture of fibroblast growth factor receptor 2 (FGFR‐2) immunoreactivity in astrocytes of neurogenic and non‐neurogenic regions of the young adult and aged rat brain
Authors: Chadashvili Tamuna , Peterson Daniel A.
Published: July 2006

Fibroblast growth factors (FGFs) are polypeptides that exert diverse biological effects on many cell types and tissues during embryogenesis and adulthood. In the adult brain, FGF‐2 is primarily expressed by astrocytes and select groups of neurons. It has been shown that FGF‐2 is neuroprotective and can stimulate proliferation of NSCs in neurogenic regions of the adult mammalian brain. Cellular responses to FGFs are mediated through membrane‐spanning tyrosine kinase receptors in conjunction with low affinity binding to heparin sulfate proteoglycans. Four FGF receptors (FGFR1–4) have been cloned and characterized to date. In this study, we describe the anatomical distribution of FGFR‐2 in young and aged rat brains. We demonstrate that the olfactory bulb, hippocampus, and cerebellum display the most robust FGFR‐2 expression and observed age‐related decrease in FGFR‐2 levels in some but not all brain regions. In addition, we identified astrocytes as the primary source of FGFR‐2 expression using immunofluorescence confocal microscopy. The astrocyte populations in the neurogenic areas, the subventricular zone (SVZ) and the subgranular zone (SGZ) of the dentate gyrus, express high levels of FGFR‐2 protein, which points to its possible involvement in neurogenesis. We also explored the role of FGFR‐2 in response to perforant pathway lesion and observed enhanced FGFR‐2 expression by astrocytes surrounding the lesion. Thus, FGF‐2 biological effects on astrocytes appear to be mediated through FGFR‐2‐dependent mechanisms, and this may provide an indirect route by which FGF‐2 acts on neuronal populations. J. Comp. Neurol. 498:1–15, 2006. © 2006 Wiley‐Liss, Inc.
Photoreceptor morphogenesis in the Drosophila compound eye: R1–R6 rhabdomeres become twisted just before eclosion
Authors: Baumann Otto , Lutz Kathleen
Published: July 2006

The photosensitive microvilli of Drosophila photoreceptors R1–R6 are not aligned in parallel over the entire length of the visual cells. In the distal half of each cell, the microvilli are slightly tilted toward one side and, in the proximal half, extremely toward the opposite side. This phenomenon, termed rhabdomere twisting, has been known for several decades, but the developmental and cell biological basis of rhabdomere twisting has not been studied so far. We show that rhabdomere twisting is also manifested as molecular polarization of the visual cell, because phosphotyrosine‐containing proteins are selectively partitioned to different sides of the rhabdomere stalk in the distal and proximal sections of each R1–R6 photoreceptor. Both the asymmetrical segregation of phosphotyrosine proteins and the tilting of the microvilli occur shortly before eclosion of the flies, when eye development in all other aspects is considered to be essentially complete. Establishment of rhabdomere twisting occurs in a light‐independent manner, because phosphotyrosine staining is unchanged in dark‐reared wild‐type flies and in mutants with defects in the phototransduction cascade, ninaE17 and norpAP24. We conclude that antiphosphotyrosine immunofluorescence can be used as a light microscopic probe for the analysis of rhabdomere twisting and that microvilli tilting represents a type of planar cell polarity that is established by an active process in the last phase of photoreceptor morphogenesis, just prior to eclosion of the flies. J. Comp. Neurol. 498:68–79, 2006. © 2006 Wiley‐Liss, Inc.
A multicriterion classification approach for assessing the impact of environmental policies on the competitiveness of firms
Authors: Hontou V. , Diakoulaki D. , Papagiannakis L.
Published: July 2006

The key objective of the European Union's environmental policy is to successfully combine environmental protection with sustainable economic growth in the long term. Nowadays, it is increasingly recognized that environmental policies, besides increasing production cost, may at the same time give incentives to firms for undertaking innovative actions and/or developing and exploiting differentiation opportunities. Both differentiation capacity and cost increase are strongly dependent on a multiplicity of internal and external factors, such as energy intensity, type of technology used, characteristics of the competitive environment etc. The present paper presents a multicriterion approach for classifying firms into discrete categories of possible impact, according to their sensitivity to cost increases and their differentiation potential. The resulting environment–competitiveness matrix can be exploited for establishing sustainability strategies and designing effective policies in the industrial sector. Copyright © 2006 John Wiley & Sons, Ltd and ERP Environment.
Study of the Reaction of 3‐Formylrifamycin SV with Gaseous Ammonia and Acetone
Authors: Bujnowski Krzysztof , Synoradzki Ludwik , Zevaco Thomas , Dinjus Eckhard , Augustynowicz‐Kopeć Ewa , Zwolska Zofia
Published: July 2006

In the second stage of our study concerning the search for new antibacterial rifamycin antibiotics, reaction of the aldehydes 3‐formylrifamycin SV (1) and 25‐O‐deacetyl‐3‐formylrifamycin SV with ammonia and acetone has been investigated. A new synthetic method for the preparation of a new group of rifamycin derivatives with a cyclic substituent at C‐3 having a 4‐piperidone structure, represented by compounds 6a, 6b, and 7a, has been developed. The structures of the compounds and a reaction mechanism have been proposed on the basis of mass spectrometry results as well as 1D and 2D 1H and 13C NMR analysis. The results of the in vitro tests confirm the antituberculous activity of the synthesized compounds. Furthermore, 6a, which is isolated in good yield, is a promising substrate for a new class of rifamycin derivatives. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Chemoenzymatic Preparation of Enantiopure Isomers of 4‐Aminochroman‐3‐ol and 1‐Amino‐1,2,3,4‐tetrahydronaphthalen‐2‐ol
Authors: Recuero Verónica , de Gonzalo Gonzalo , Brieva Rosario , Gotor Vicente
Published: July 2006

Enantiomerically pure N‐protected cis‐4‐aminochroman‐3‐ol (key precursor in the synthesis of novel HIV second‐generation protease inhibitors), its trans isomer and both cis‐ and trans‐1‐amino‐1,2,3,4‐tetrahydronaphthalen‐2‐ol, useful chiral catalysts in organic synthesis, have been successfully prepared through a lipase‐catalyzed kinetic acylation of the alcohol moiety, employing as substrates the corresponding N‐benzyloxycarbonyl‐protected derivatives. Of the biocatalysts tested, Pseudomonas cepacea and Candida antarctica B lipases showed excellent enantioselectivities in the acylation processes depending on the reaction conditions employed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Joule heating effects on separation efficiency in capillary zone electrophoresis with an initial voltage ramp
Authors: Xuan Xiangchun , Hu Guoqing , Li Dongqing
Published: July 2006

An analytical model is developed to quantify the Joule heating effects on the separation efficiency in CZE with an initial voltage ramp. This model considers the temporal variations of nonuniform temperature and flow fields in the course of voltage ramping. The temperature dependence of electrical conductivity, dynamic viscosity, and mass density of the fluid is also taken into account. We demonstrate that the application of an initial voltage ramp delays the development of pressure‐driven flows induced passively by the axial temperature gradients. The thermal dispersion is thus significantly reduced, resulting in a higher theoretical plate number in CZE. Such improvement in the separation efficiency is apparent in noncoated capillaries at high electric fields with an appropriate voltage ramp‐up time. These predictions are consistent with previous observations in both aqueous and nonaqueous CZE that took place in uncoated capillaries. In coated capillaries where the EOF is suppressed, however, our model predicts a lower plate number in the presence of an initial voltage ramp.
Carbon nanotube/poly(methyl methacrylate) composite electrode for capillary electrophoretic measurement of honokiol and magnolol in Cortex Magnoliae Officinalis
Authors: Yao Xiao , Xu Xuejiao , Yang Pengyuan , Chen Gang
Published: July 2006

This paper describes the development and the application of a novel carbon nanotube/poly(methyl methacrylate) (CNT/PMMA) composite electrode as a sensitive amperometric detector of CE. The composite electrode was fabricated on the basis of the in situ polymerization of a mixture of CNT and prepolymerized methylmethacrylate in the microchannel of a piece of fused‐silica capillary under heat. The performance of this unique system has been demonstrated by separating and detecting honokiol and magnolol in traditional Chinese medicine, Cortex Magnoliae Officinalis. Factors influencing their separation and detection processes were examined and optimized. Honokiol and magnolol were well separated within 7 min in a 40 cm long capillary at a separation voltage of 15 kV using a 50 mM borate buffer (pH 9.2). The new CNT‐based CE detector offered significantly lower operating potentials, yielded substantially enhanced S/N characteristics, and exhibited resistance to surface fouling and hence enhanced stability. It demonstrated long‐term stability and reproducibility with RSDs of less than 5% for the peak current (n = 9) and should also find a wide range of applications in microchip CE, flowing injection analysis, and other microfluidic analysis systems.
Levodopa can worsen tremor associated with dystonia
Authors: Hensman Davina J. , Bain Peter G.
Published: July 2006

A patient with tremor associated with spasmodic dysphonia developed a marked exacerbation of her upper limb tremor whilst on co‐careldopa (Sinemet CR) that improved when the drug was withdrawn. © 2006 Movement Disorder Society
Chorea induced by globus pallidus externus stimulation in a dystonic patient
Authors: Mouton Servane , Xie‐Brustolin Jing , Mertens Patrick , Polo Gustavo , Damier Philippe , Broussolle Emmanuel , Thobois Stéphane
Published: July 2006

Bilateral high‐frequency stimulation of the internal part of the pallidum has proven its efficacy in improving motor symptoms of dystonia. In Parkinson's disease, the stimulation of the external pallidum (GPe) can induce dyskinesias. This has never been described in dystonia. We report here a case of abnormal movements induced by the stimulation of GPe in a dystonic patient and discuss the pathophysiological mechanisms. © 2006 Movement Disorder Society
Interplay of relativistic and nuclear effects in few‐electron atoms and ions
Authors: Sapirstein J.
Published: July 2006

After the basic physics of the Schrödinger equation is solved for in atomic systems, discrepancies with experiment arise from relativistic effects, quantum electrodynamic effects, and the fact the nucleus is not a point‐like particle. While the nuclear effects are small, valuable nuclear physics information can be obtained from high‐precision exeriments if the non‐nuclear part of the problem can be controlled with similar precision. Recent progress in the accurate evaluation of relativistic and QED effects will be described, which gives information on a number of few‐nucleon nuclei where theoretical progress has also been made by nuclear theorists. Examples of this interplay will be given, including a study of the so‐called “halo” nucleus helium‐6 through isostope shift experiments and the charge radii determination of the proton. In addition, the more complicated nuclear problem of the magnetization distribution in the bismuth nucleus will be shown to be probed because of experimental and theoretical advances in the study of hyperfine splitting in hydrogen‐like and lithium‐like bismuth. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Theoretical studies of the effect of pair scattering process on two‐gap superconductivity in Eliashberg theory
Authors: Nagao Hidemi , Kawabe Hiroyuki
Published: July 2006

Two‐gap superconductivity is investigated from the viewpoint of strong electron–phonon coupling including effective electron–electron interaction within an extension of the Eliashberg theory. The two‐band Eliashberg theory is extended to a more general formalism, including the pair scattering process between two bands. We present a coupled extended Eliashberg equation. We discuss the contribution of effective electron–electron interaction and the electron–phonon coupling to two‐gap superconductivity in relation to frequency dependence, using the extended Eliashberg equation and a model for phonon spectral density. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Reconstructing Past Climatic Anomalies in the North Pacific and Western North America from Tree-Ring Data
Authors: Blasing T.J. , Fritts H.C.
Published: July 2006

Winter climatic anomalies in the North Pacific sector and western North America are statistically calibrated with tree-ring data in western North America and reconstructed back to AD 1700. The results are verified using climatic data from the last half of the 19th century, which is prior to the calibration period. Climatic conditions reconstructed for 18th and 19th century winters are then summarized and compared with the 20th century record.
The Relevance of Old World Archaeology to the First Entry of Man into New Worlds: Colonization Seen from the Antipodes
Authors: Hallam Sylvia J.
Published: July 2006

Following several discussions in recent numbers of Quaternary Research on the peopling of the Americas, this paper suggests that movements into the New World should be viewed in the wider context of subsistence, technology, and movement around the western littorals of the Pacific, resulting in the colonization not of one but of two new continents by men out of Asia. Specific points which have been raised by these recent papers are reviewed in the light of Australian, Wallacian, and East Asian data.

(1) The earliness of watercraft is evidenced by chronology of the human diaspora through Wallacia and Greater Australia.

(2) The simplistic nomenclature of chopper-flake traditions masks considerable complexity and technological potential, revealed in detailed Antipodean studies.

(3) These traditions also have great potential for adapting to differing ecological zones, evidenced within Greater Australia; and for technological and economic innovation there, through Southeast Asia, and to Japan and the north Asian littoral.

(4) The history of discovery and the nature of the evidence from Australia cannot validly be used to controvert early dates in the Americas.

(5) Demographic data from Australia suggest that total commitment to a rapid-spread “bowwave” model for the peopling of new continents may be unwise.
Resistivity Investigation of an Infilled Kettle Hole
Authors: Thompson R.
Published: July 2006

An electrical resistivity survey of a lacustrine infilled basin in drift (Abbot Moss, N. England) clearly revealed the morphometry and internal structure of the basin. The technique also delimited extensions to the basin, which are buried beneath colluvium outside the present area of peat accumulation. Resistivity drilling has definite advantages over hand boring particularly for deposits formed between deglaciation and the onset of limnic sedimentation, or for sequences containing inpenetrable sand horizons. Geophysical techniques can provide an overall framework and gross stratigraphy of limnic deposits within which more detailed conventional Quaternary studies can be assessed.
The Mode and Mechanism of the Last Deglaciation: Oceanic Evidence
Authors: Ruddiman W. F. , McIntyre A.
Published: July 2006

Changes in ocean temperature, carbonate productivity, and ice-rafted detritus in the North Atlantic suggest that half of the Northern Hemisphere ice volume at the last glacial maximum had disappeared by 13,000 yr B.P., despite the still-extensive limits of the ice sheets. This early thinning of the ice sheets occurred during a time when summer insolation values were slowly rising but when pollen evidence south of the ice margins indicates cold, dry air masses. We infer that this rapid early ice disintegration (16,000–13,000 yr B.P.) was caused by oceanic mechanisms: (1) rising sea level, causing increased calving along ice margins; (2) the chilling of the sea-surface by icebergs and meltwater, reducing moisture extraction by the atmosphere and transport to the ice sheets; and (3) winter freezing of the low-salinity meltwater layer, suppressing local moisture extraction and the regional influx of moisture-bearing storms from lower latitudes in winter and hence starving the ice sheets. These oceanic feedback mechanisms were strongest from 16,000 to 13,000 yr B.P., and weaker but still active from that date until the end of deglaciation at 6000 yr B.P.
Invertebrate Fossils (Insecta: Trichoptera, Diptera, Coleoptera) from the Pleistocene Scarborough Formation at Toronto, Ontario, and their paleoenvironmental Significance
Authors: Williams Nancy E. , Westgate John A. , Williams D. Dudley , Morgan Anne , Morgan Alan V.
Published: July 2006

Larval caddisfly, chironomid, and beetle remains have been recovered from the Pleistocene Scarborough Formation in the Toronto region of southern Ontario. Three stratigraphic levels were sampled at the northeastern end of the Scarborough Bluffs; the youngest horizon yielded 16 chironomid taxa, 33 caddisfly taxa, and 28 beetle taxa, whereas the two older levels yielded somewhat less diverse assemblages. Only one taxon in each of the caddisfly and chironomid groups was identified from the presumed correlative beds at Woodbridge, Ontario, but numerous beetle fragments were recovered, several of which have been specifically identified and match species found previously in the upper part of the Scarborough Formation. The youngest sampled assemblage in the Scarborough Formation at the northeastern end of the Scarborough Bluffs is interpreted as indicating cool climatic conditions in a boreal forest environment, given the present-day distributions and feeding habits of these river, lake, and terrestrial taxa. The mean July temperature at this time was probably about 15°C, as compared to the present-day value of 20.5°C. The forest was poorer in deciduous species during deposition of the older part of the formation as preserved here. These results agree well with previous interpretations based on plant remains. We suggest that both aquatic and terrestrial insects are good indicators of macroclimate.
Latest Pleistocene Increase in Wind Intensity Recorded in Eolian Sediments from Central Alaska
Authors: Bigelow Nancy , Begét Jim , Powers Roger
Published: July 2006

A brief increase in wind intensity between ca. 11,100 and 10,700 yr B.P. is recorded by a sharp increase in sediment grain size at eolian sections along the Nenana River in central Alaska. This occurred at the same time as the Younger Dryas climatic reversal in northern Europe and an increase in the vigor of atmospheric circulation recorded by Greenland ice cores. Climatic fluctuations in high latitude areas during Younger Dryas time may reflect variations in the CO2 content of the atmosphere.
Taphonomy of Guanaco Bones in Tierra del Fuego
Authors: Borrero Luis Alberto
Published: July 2006

Guanaco carcasses are deposited in great quantities in Cabo San Pablo, Tierra del Fuego (Argentina), as a result of winter stress. Taphonomic studies indicate that the gnawing action of foxes on guanaco (Lama guanicoe) carcasses produces only very tenuous marks on the bones. Lack of sustained interest in the carcasses by carnivores results in slow disarticulation. The articulated and disarticulated bones are exposed to heavy trampling by guanacos, a process that produces vertical migration of small/dense bones and fracturing of the most weathered bones. An understanding of this ongoing process is important for local archaeology, since modern bones are migrating into archaeological contexts. A regional approach to taphonomy is the most appropriate instrument to solve this and other related problems.
Intestinal contents of a late Pleistocene mastodont from midcontinental north America
Authors: Lepper Bradley T. , Frolking Tod A. , Fisher Daniel C. , Goldstein Gerald , Sanger Jon E. , Wymer Dee Anne , Ogden J.Gordon , Hooge Paul E.
Published: July 2006

Salvage excavations of a nearly complete and remarkably well-preserved skeleton of an American mastodont (Mammut americanum) in Licking County, Ohio, yielded a discrete, cylindrical mass of plant material found in association with articulated vertebrae and associated ribs. This material is interpreted as intestinal contents of the mastodont and paleobotanical analyses indicate that the mastodont diet included significant amounts of low, herbaceous vegetation. Enteric bacteria (Enterobacter cloacae), isolated from a sample of this material, are believed to represent survivors or descendants of the intestinal microflora of the mastodont. This is the first report of the isolation of bacteria associated with late Pleistocene megafauna.
Postpartum evaluation of stress urinary incontinence among primiparas
Authors: Eftekhar T. , Hajibaratali B. , Ramezanzadeh F. , Shariat M.
Published: July 2006

Objective: To assess the prevalence of postpartum stress urinary incontinence (SUI); the relationship between postpartum SUI and mode of delivery; and the association between SUI and other obstetric factors.

Method: In this prospective study, 1000 primiparas with no history of UI were recruited and followed up for 4 months after delivery. The χ2 and Fisher's Exact tests were used to calculate the effects of the nominal variables.

Result: The prevalence of postpartum SUI was 14.1%, and the mode of delivery was significantly associated with SUI. The prevalence rates were 15.9% after vaginal delivery, 10.7% after elective cesarean section (CS), and 25% after CS performed for obstructed labor. The prevalence of postpartum SUI was similar following spontaneous vaginal delivery and CS performed for obstructed labor (P = .21). Meanwhile, elective CS with no trial of labor was found to be associated with a significantly lower prevalence of postpartum SUI (P = .01; χ2 = 12.42). A maternal body mass index greater than 30 before pregnancy and fetal weight higher than 3000 g appeared to be associated with an increased rate of SUI (P = .001; χ2 = 17.6 and P = .000; χ2 = 22.5, respectively).

Conclusion: Elective CS significantly reduced the rate of postpartum SUI.
Ossiculoplasty: a UK survey
Authors: Dhanasekar G , Khan H K , Malik N , Wilson F , Raut V V
Published: July 2006

The aim of this study was to assess and quantify the current surgical practice of ossiculoplasty among British otolaryngology consultants, using a postal questionnaire. Ossiculoplasty is not a very common procedure. It is only performed by otologists with a special interest in ossiculoplasty. Among the 280 respondents (response rate 51.9 per cent), only 179 (63.9 per cent) performed ossiculoplasty. The majority of the consultants (86.5 per cent) used artificial prostheses, and 63.7 per cent used patients' own ossicles (autografts). Most of the consultants (77.6 per cent) performed ossiculoplasty with primary tympanoplasty surgery rather than with primary cholesteatoma surgery (46.3 per cent). The majority of the consultants (50.8 per cent) performed less than 10 ossiculoplasties per year.

This is the first survey on ossiculoplasty surgery in the United Kingdom.
Spectrum analysis of plasma produced by pulsed laser ablation of GaAs
Authors: LIU AI HUA
Published: July 2006

A time-resolved diagnostic technique was used to investigate the emission spectra from the plasmas produced by 1.06 μm, 10 ns pulsed laser ablation of semiconductor GaAs. The characteristics of the species in plasma produced at different ambient pressure were analyzed. The full width at half maximum of the spectral line was measured and analyzed according to obtained spectra of the excited atoms; several line broadening factors were estimated according to our experimental conditions and the results indicate that the Stark broadening is the main broadening mechanism. Under the assumption of local thermodynamic equilibrium, the time evolution of electron number density was deduced from the Stark broadening measurements.
IN THIS ISSUE
Authors: MORGAN CRAIG
Published: July 2006

This issue contains two reviews on cognitive reserve and decline, and five further papers examine various aspects of cognition and psychiatric disorder. Three papers focus on aspects of depression, and three individual papers examine a variety of topics.
Mass Media and the Generation of Conflict: West Germany's Long Sixties and the Formation of a Critical Public Sphere
Authors: VON HODENBERG CHRISTINA
Published: July 2006

From the 1950s to 1970s the West German public sphere underwent a rapid politicisation which was part of the ongoing socio-cultural democratisation of the Federal Republic. This article examines the role of the mass media and journalistic elites in bringing about this change. It analyses how and when political coverage in the media evolved from an instrument of consensus to a forum of conflict. Arguing that generational shifts in journalism were crucial to this process, two generations, termed the ‘45ers’ and the ‘68ers’, are described in regard to their professional ethos and their attitudes toward democracy, mass culture, German traditions and Western models.
Langzeitverlauf nach thyreostatischer Therapie bei Basedow-Hyperthyreose
Authors: Wille  , Müller  , Noth  , Bürgi  , Diem
Published: July 2006

Hintergrund und Ziel: Die thyreostatische Therapie stellt in Europa bei Patienten mit Erstmanifestation einer Basedow-Hyperthyreose die Therapie der Wahl dar. Die Resultate von Langzeitverlaufsstudien berichten über kontroverse Daten bezüglich Remissions- bzw. Rezidivraten. Hauptuntersuchungsziel waren die Remissions- bzw. Rezidivraten. Sekundär untersuchten wir laborchemische und klinische Befunde (Thyreotropin-Rezeptor-AK (TRAK)-Titer, initiale Therapiedauer, Alter, Struma) bezüglich der Verwertbarkeit als prognostische Faktoren. Patienten und Methoden: Es wurden retrospektiv Daten von 94 Patienten mit Erstmanifestation einer Basedow-Hyperthyreose (1990–1995), welche initial thyreostatisch behandelt wurden, analysiert. 18 Patienten gingen im Follow-up verloren, die verbliebenen 76 (65 Frauen, 11 Männer, Alter 16–76 Jahre) wurden während 99 (± 22) Monaten (Mittelwert ± Standardabweichung) beobachtet. Die prognostischen Faktoren wurden mittels logistischer Regressionsanalyse bestimmt. Ergebnisse: 16 Patienten wurden unmittelbar nach der primären thyreostatischen Behandlung einer (meist) subtotalen Schilddrüsenresektion (N = 5) oder einer Radiojodtherapie (N = 11) zugeführt. 60 Patienten wurden während 19 (± 16) Monaten behandelt und waren zum Zeitpunkt des Absetzens der Thyreostatika euthyreot. Bei 13 Patienten (21.7%) trat eine Vollremission ein, die während 89 (± 23) Monaten nach Therapiestopp (bis zum Zeitpunkt der Datenerhebung) anhielt, bei 42 Patienten (70%) trat eine Rezidivhyperthyreose auf, bei vier Patienten (6.7%) konnten die Thyreostatika nicht abgesetzt werden, bei einem Patient (1.7%) trat eine Späthypothyreose auf. Die Rezidivrate korrelierte invers mit der Dauer der initialen thyreostatischen Therapie (p < 0.05). Das Alter der Patienten bei Diagnosestellung korrelierte tendenziell ebenfalls invers mit der Rezidivrate (p = 0.055). Dem TRAK-Titer bei Diagnosestellung und zum Zeitpunkt des Sistierens der primären thyreostatischen Therapie konnte keine Bedeutung zugeschrieben werden (p > 0.05). Ebenfalls keine prognostische Bedeutung hatte die Strumagrösse bei Diagnosestellung (p > 0.05). Folgerung: Auch bei initial erfolgreicher Behandlung mit Thyreostatika war die Rezidivrate in unserer Patientenpopulation sehr gross. Zwei mögliche negative prognostische Faktoren bezüglich Rezidiventwicklung sind kurze initiale thyreostatische Therapiedauer und junges Alter bei Diagnosestellung. Die TRAK-Titer haben in unserer Patientenpopulation keine prognostische Bedeutung. Ebenso kann keine Korrelation der Strumagrösse mit einer Rezidiventwicklung nachgewiesen werden.
Von der Sonne gebräunt und doch nicht gesund!
Authors: Spörri  , Mullis
Published: July 2006

Wir beschreiben eine Notfallsituation einer 10-jährigen Patientin mit unspezifischen intestinalen Symptomen und grosser Müdigkeit in einem Schockzustand. Die rasche Bestimmung der Blutgaswerte, der Elektrolyte und Glukose führt uns schnell zur Diagnose einer lebensbedrohlichen Addison-Krise. Die Pathophysiologie und Therapie dieser Entität wird kurz beschrieben, wobei man beachten muss, dass im Kindesalter die Ätiologie der Addison-Krise alters- und geschlechtsspezifisch ist. Die Familienanamnese der Patientin ist stark belastet mit Autoimmunopathien. Auch bei ihr konnte ein Autoimmungeschehen diagnostiziert werden. Dies in Form einer Polyendokrinopathie mit Autoimmunadrenalitis und Zöliakie. Unter einer Erhaltungstherapie mit Florinef® (Mineralkortikoid), Hydrocorton® (Hydrocortison) und glutenfreier Diät ist die Patientin heute symptomfrei.
Akute Methämoglobinämie bei Vergiftung
Authors: von Orelli-Straubhaar  , Ronsdorf
Published: July 2006

Eine akute Zyanose durch Methämoglobinbildung bei einer Vergiftung mit Anilin wird hier beschrieben. Die Diskrepanz zwischen der Pulsoxymetrie (tiefe Sättigung) und dem PaO2 (normwertig) wird als Sättigungslücke (saturation gap) bezeichnet und weist auf eine Methämoglobinämie hin.
Is ambient noise tomography across ocean basins possible?
Authors: Lin Fan‐Chi , Ritzwoller Michael H. , Shapiro Nikolai M.
Published: July 2006

Based on year‐long cross‐correlations of broad‐band seismic records obtained at sixty‐six stations within or adjacent to the Pacific Basin, we show that broad‐band ambient noise is observed to propagate coherently between island stations and between island and continent stations. For many station pairs, high signal‐to‐noise ratio (SNR) fundamental mode Rayleigh wave Green functions are observed, which establishes the physical basis for ambient noise tomography across the Pacific. Similar trends for continental and oceanic stations are observed in the relationship between the ambient noise level at a station and the “noise coherence distance” – the longest distance at which a high SNR cross‐correlation signal is observed for a station. Because locally generated noise obscures long distance coherent noise, situating stations at quiet locations on islands is necessary for the success of ambient noise tomography. Local noise poses a particular challenge at atoll sites and, on the basis of analysis of data from station H2O, at ocean bottom sites at periods above ∼25 sec.
Pump-probe experiments at 1.54μm on silicon-rich silicon oxide waveguides
Authors: Forcales M. , Smith N. J. , Elliman R. G.
Published: July 2006

Optical pump-probe measurements were performed on slab waveguides containing excess silicon in the form of nanoclusters or nanocrystals and erbium. The measurements were performed by prism coupling a 1.54μm probe beam into a waveguide formed by silicon-rich oxide and monitoring its intensity and temporal response as the waveguide was optically pumped from above with a chopped 477nm excitation source. Induced absorption (losses) of the 1.54μm probe beam in erbium-doped and undoped silicon-rich silicon oxide waveguides was observed in all cases. For the samples containing only well-defined nanocrystals, a fast (∼60μs) induced absorption component associated with free carriers within the silicon nanocrystals is reported, while for samples containing defective nanocrystals or nanoclusters, a much slower (>10min) component is observed. The free carrier absorption is shown to be reduced by delaying the probe beam relative to the pump beam in cases where it dominates.
A wave function based
ab initio
nonequilibrium Green’s function approach to charge transport
Authors: Albrecht Martin , Song Bo , Schnurpfeil Alexander
Published: July 2006

We present an ab initio nonequilibrium approach to calculate the current across a molecular junction. The method rests upon a wave function based description of the central region of the junction combined with a tight binding approximation for the electrodes in the frame of the Keldysh Green’s function formalism. In addition we present an extension so as to include effects of the two-particle propagator. Our procedure is demonstrated for a dithiolbenzene molecule between silver electrodes. The full current-voltage characteristic is calculated. Specific conclusions for the contribution of correlation and two-particle effects are derived. The latter are found to contribute about 5% to the current. The order of magnitude of the current coincides with experiments.
Molecular dynamics and interactions of aqueous and dichloromethane solutions of polyvinylpyrrolidone
Authors: Shirota Hideaki , Castner Edward W.
Published: July 2006

We have investigated the dynamics of polyvinylpyrrolidone solutions (PVP, Mw=10000) on time scales from 20fsto42ps using femtosecond optically heterodyne-detected Raman-induced Kerr effect spectroscopy. To compare the dynamics of polymer solutions with those of the analogous monomer, we also characterized solutions of 1-ethyl-2-pyrrolidone (EP). Dynamics of both PVP and EP solutions have been characterized for sample concentrations of 6.4, 12.7, 24.5, 33.3, and 40.7wt%. The longest time scale relaxations observed in the Kerr transients for these solutions occur on the picosecond time scale and are best fit to triexponential functions. The intermediate and slow relaxation time constants for PVP and EP solutions are concentration dependent. The time constants for the PVP solutions are not consistent with the predictions of hydrodynamic models, while the analogous time constants for the EP solutions do display hydrodynamic scaling. The predominant relaxation of the polymer is assigned to reorientations of the pyrrolidone side group or torsional motions of the constitutional repeat unit, with additional relaxation pathways including hydrogen bond reorganization in aqueous solution and segmental motion of multiple repeat units. The vibrational dynamics of PVP and EP solutions occur on the femtosecond time scale. These dynamics are analyzed with a focus on the additional degrees of freedom experienced by EP relative to PVP that result from the absence of the tether from the pyrrolidone group on the main chain backbone. The intermolecular Kerr spectra of PVP in H2O and CH2Cl2 differ because H2O can donate a hydrogen bond to the carbonyl acceptor group on the pyrrolidone ring, while CH2Cl2 cannot.
Acoustic phonon confinement in silicon nanolayers: Effect on electron mobility
Authors: Donetti L. , Gámiz F. , Roldán J. B. , Godoy A.
Published: July 2006

We demonstrate the confinement of acoustic phonons in ultrathin silicon layers and study its effect on electron mobility. We develop a model for confined acoustic phonons in an ideal single-layer structure and in a more realistic three-layer structure. Phonon quantization is recovered, and the dispersion relations for distinct phonon modes are computed. This allows us to obtain the confined phonon scattering rates and, using Monte Carlo simulations, to compute the electron mobility in ultrathin silicon on insulator inversion layers. Thus, comparing the results with those obtained using the bulk phonon model, we are able to conclude that it is very important to include confined acoustic phonon models in the electron transport simulations of ultrathin devices, if we want to reproduce the actual behavior of electron transport in silicon layers of nanometric thickness.
Ultraviolet emission from porous silicon photosynthesized in aqueous alkali fluoride solutions
Authors: Uchida Kaoru , Tomioka Katsuhiro , Adachi Sadao
Published: July 2006

Stable ultraviolet (UV) photoluminescence (PL) has been observed at room temperature in porous silicon (PSi) fabricated by photoetching in aqueous alkali fluoride solutions. The aqueous solutions used are 1M NaF and 1M KF. They give an alkaline reaction caused by partial hydrolysis. The PL peaks at ∼3.3eV have a full width at half maximum of ∼0.1eV, which is much smaller than those reported previously (⩾0.5eV). Spectral analyses suggest that both quantum confinement and surface passivation effects enable the observation of UV emission in NaF- and KF-prepared PSi samples.
The doping effect of multiwall carbon nanotube on MgB2∕Fe superconductor wire
Authors: Kim J. H. , Yeoh W. K. , Qin M. J. , Xu X. , Dou S. X.
Published: July 2006

We evaluated the doping effect of two types of multiwall carbon nanotubes (CNTs) with different aspect ratios on MgB2∕Fe monofilament wires. Relationships between microstructure, magnetic critical current density (Jc), critical temperature (Tc), upper critical field (Hc2), and irreversibility field (Hirr) for pure and CNT doped wires were systematically studied for sintering temperature from 650to1000°C. As the sintering temperature increased, Tc for short CNT doped sample slightly decreased, while Tc for long CNT doped sample increased. This indicates better reactivity between MgB2 and short CNT due to its small aspect ratio, and substitution of carbon (C) from short CNT for boron (B) occurs. In addition, short CNT doped samples sintered at high temperatures of 900 and 1000°C exhibited excellent Jc, and this value was approximately 104A∕cm2 in fields up to 8T at 5K. This suggests that short CNT is a promising carbon source for MgB2 superconductor with excellent Jc. In particular, inclusion of nanosized MgO particles and substitution of C into the MgB2 lattice could result in strong flux pinning centers.