bluuebunny/crossref_metadata_2025 huggingface dataset:
Polycondensation of α‐amino acid esters in the presence of yttrium triflate as a Lewis acid
Authors: Nemoto Tadamasa , Ando Daisuke , Naka Kensuke , Chujo Yoshiki
Published: July 2006

To develop polycondensation methods for poly(α‐amino acid)s, we describe a first examination to use yttrium triflate as a Lewis acid for polycondensation of α‐amino acid esters. In the absence of Lewis acid, no polycondensation of 2‐methoxyphenyl glycinate (1b) at room temperature proceeded. While the polycondensation of 1b was carried out with 5 mol % yttrium triflate, a condensation product of glycine was obtained in 16% yield. Although polycondensation of 4‐nitrophenyl L‐leucinate (1c) and 4‐nitrophenyl L‐valinate (1d) were also promoted with 5 mol % yttrium triflate, the condensation products of both α‐amino acid esters were obtained in only a few percent yield. When 1d was polymerized in the presence of 100 mol % yttrium triflate, high molecular weight poly(L‐valine) was obtained in 91% yield. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4731–4735, 2006
Segmented block copolymers based on poly(propylene oxide) and monodisperse polyamide‐6,T segments
Authors: van der Schuur Martijn , Gaymans Reinoud J.
Published: July 2006

Polyether(ester amide)s with poly(propylene oxide) (PPO) and monodisperse poly(hexamethylene terephthalamide) segments were synthesized, and their structure–property relations were investigated. The length of the amide segments was varied from diamide to tetraamide to hexaamide segments, and therefore the number hydrogen bonds per amide segment increased from two to four to six. PPO was end‐capped with 20 wt % ethylene oxide and had number‐average molecular weights of 1000, 2300, and 4000 g/mol (including ethylene oxide tips). The morphology of the poly‐ether(ester amide)s was studied with transmission electron microscopy and atomic force microscopy, the thermal properties were studied with differential scanning calorimetry and dynamic mechanical thermal analysis, and the tensile properties were studied with dumbbell samples. The elastic behavior of the block copolymers was investigated with tensile and compression tests. These segmented copolymers had two sharp transitions: a glass‐transition temperature (Tg) of the PEO–PPO–PEO phase [where PEO is poly(ethylene oxide)] and a melting temperature (Tm) of the amide segments. The amide segments crystallized in nanoribbons with a high aspect ratio 1000. Tm increased with the amide segment length and with decreasing PEO–PPO–PEO content (solvent effect). The modulus increased strongly with the amide content. This modulus increase could be described by the Halpin–Tsai fiber composite model. Increasing the amide segment length surprisingly also improved the elasticity. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4769–4781, 2006
7‐Coumaryl permethrate and its cis‐ and trans‐isomers as new fluorescent substrates for examining pyrethroid‐ cleaving enzymes
Authors: Santo Orihuela Pablo L , Picollo María I , Audino Paola Gonzalez , Barrios Silvia , Zerba Eduardo , Masuh Héctor
Published: July 2006

New esterase substrates were synthesized using cis‐, trans‐ and cis‐trans‐permethrinic acid chloride and then used to measure pyrethroid‐cleaving enzymes in insects. The new substrates, namely cis‐, trans‐ and cis‐trans‐7‐coumaryl permethrates (7‐CP), show a structure very similar to permethrin insecticide and yield fluorescent products on hydrolysis. These substrates were hydrolyzed by a commercial porcine preparation that provided esterase‐specific activity, and were stable at different pH values (5.2–7.8). Studies made with house fly, Musca domestica (L.), homogenates showed that these compounds are appropriate for determining pyrethroid hydrolysis activity on individual insects. The measured activity of house fly esterase was 870 relative fluorescence units (RFU) min−1 with cis‐7‐CP as substrate, 1117 RFU min−1 with trans‐7‐CP as substrate and 1423 RFU min−1 with cis‐trans‐7‐CP as substrate. The fluorescent substrates for pyrethroid‐cleaving esterases described in this paper have advantages over methods already given in the literature. They are substrates with structures very similar to pyrethroids, the cleavage of which can be followed by an increase in fluorescence emission at 440 nm; it takes only about 5 min to measure the reaction, and moreover the high sensitivity of the fluorescence technique allows the quantification of esterase activity on individual insects. Copyright © 2006 Society of Chemical Industry
Hybrid HF‐DFT comparative study of SrZrO3and SrTiO3(001) surface properties
Authors: Evarestov R. A. , Bandura A. V. , Alexandrov V. E.
Published: July 2006

Hybrid HF‐DFT LCAO simulations of SrZrO3and SrTiO3(001) surface properties are performed in a single‐slab model framework. The SrZrO3(001) surface was studied by an ab initio method for the first time. Three slab models with different surface terminations including up to 8 atomic planes were used for calculation of the various surface characteristics (surface energies, atomic charges, density of electronic states). The dependence of the results on the chosen model and on the kind ofd‐element is analyzed. The dissimilarity in the surface oxygen atom contributions to the total density of states of two crystals is attributed to the more ionic nature of Zr–O bonds compared to Ti–O bonds. It is found that in the case of SrZrO3the electronic density is biased towards the SrO‐terminated surface and this surface should be more basic in nature than the SrO surface of SrTiO3crystal. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of stable carbon isotopes of organic acids and carbonaceous aerosols in the atmosphere
Authors: Fisseha R. , Saurer M. , Jäggi M. , Szidat S. , Siegwolf R. T. W. , Baltensperger U.
Published: July 2006

A wet oxidation method for the compound‐specific determination of stable carbon isotopes (δ13C) of organic acids in the gas and aerosol phase, as well as of water‐soluble organic carbon (WSOC), is presented. Sampling of the organic acids was done using a wet effluent diffusion denuder/aerosol collector (WEDD/AC) coupled to an ion chromatography (IC) system. The method allows for compound‐specific stable carbon isotope analysis by collecting different fractions of organic acids at the end of the IC system using a fraction collector. δ13C analyses of organic acids were conducted by oxidizing the organic acids with sodium persulfate at a temperature of 100°C and determining the δ13C value of the resulting carbon dioxide (CO2) with an isotope ratio mass spectrometer. In addition, analysis of δ13C of the WSOC was performed for particulate carbon collected on aerosol filters. The WSOC was extracted from the filters using ultrapure water (MQ water), and the dissolved organic carbon was oxidized to CO2 using the oxidation method. The wet oxidation method has an accuracy of 0.5‰ with a precision of ±0.4‰ and provides a quantitative result for organic carbon with a detection limit of 150 ng of carbon. Copyright © 2006 John Wiley & Sons, Ltd.
Micro‐beam x‐ray fluorescence analysis of individual particles with correction for absorption effects
Authors: Bielewski M. , Wegrzynek D. , Lankosz M. , Markowicz A. , Chinea‐Cano E. , Akoto Bamford S.
Published: July 2006

A method of correction for absorption effects in micro‐beam x‐ray fluorescence analysis is described. A fast, energy‐dispersive, silicon drift detector (SDD) was used to measure the primary x‐ray beam transmitted through the sample. The absorption factors were calculated using the data acquired with the SDD. The possibility of using the coherently, incoherently and multiple scattered primary radiation for determining the mass of individual particles was examined. The proposed methods were validated with the use of NIST K3089 glass micro‐spheres of known composition. Copyright © 2006 John Wiley & Sons, Ltd.
Improved Long‐term Survival after Liver Resection for Hepatocellular Carcinoma in the Modern Era: Retrospective Study from HCV‐endemic Areas
Authors: Sasaki Atsushi , Iwashita Yukio , Shibata Kohei , Matsumoto Toshifumi , Ohta Masayuki , Kitano Seigo
Published: July 2006

Introduction

It remains unclear whether recent progress in perioperative management and treatment for recurrent hepatocellular carcinoma (HCC) has improved patient outcomes in hepatitis C virus‐endemic areas.

Methods

The clinicopathologic and follow‐up data of 218 consecutive HCC patients who underwent curative resection between 1982 and 2003 were analyzed. Patients were assigned to one of two groups: before 1992 (early group; n = 82) and 1992 and later (late group; n = 136). Factors influencing survival rates were investigated by multivariate analysis. The effects of the period during which the hepatic resection was done on the patients’ outcome were examined with respect to tumor size.

Results

The 5‐year cancer‐related and disease‐free survival rates were 51.4% and 20.4%, respectively. The late group showed better 5‐year cancer‐related survival than the early group (64.1% vs. 33.8%), but disease‐free survival did not differ significantly between the groups. On multivariate analysis, the period of the hepatic resection was identified as an independent prognostic factor for cancer‐related survival (relative risk 0.70, P < 0.01) but not disease‐free survival. There were no differences in the cancer‐related and disease‐free survival rates between the two groups for patients with tumors ≤ 25 mm. In patients with HCCs > 50 mm, both cancer‐related and disease‐free survival rates were better in patients in the late group.

Conclusions

During the past two decades, improvements in the treatment of recurrent HCC tumors have contributed to controlling large HCCs but not to controlling the multicentric development of HCCs. It may be important to control multicentric recurrence of HCC to improve patient survival in areas where the hepatitis C virus is endemic.
Necrotic Complications after Nipple‐ and Areola‐Sparing Mastectomy
Authors: Komorowski Andrzej L. , Zanini Vittorio , Regolo Lea , Carolei Adriana , Wysocki Wojciech M. , Costa Alberto
Published: July 2006

Objective

The objective was to analyze the frequency and factors influencing necrotic complication in female patients undergoing nipple‐ and areola‐sparing mastectomy.

Summary and background data

Nipple‐ and areola‐sparing mastectomy has recently been shown to yield satisfactory results in a carefully selected group of breast cancer patients. The technique includes extensive undermining of the nipple–areola complex, which may result in an increased rate of necrotic complications. We report our early experience with necrotic changes after nipple‐ and areola‐sparing mastectomy.

Methods

The medical records of 38 patients undergoing nipple‐ and areola‐sparing mastectomy were analyzed retrospectively.

Results

Mean age of the patient was 44.5 years (range 26–65). Necrotic complications occurred in 15.8% of patients and included: skin flap necrosis (1 case), partial nipple–areola complex necrosis (2 cases), and complete nipple–areola complex necrosis (3 cases). Two cases of capsular contraction were also recorded. Statistical analysis showed age below 45 years to be associated with a lower risk of necrotic complications (OR 4.51, P < 0.05).

Conclusions

The nipple‐ and areola‐sparing mastectomy, although resulting in a relatively high frequency of necrotic complications, is a valuable surgical option for patients with small, peripheral tumors and for women undergoing prophylactic mastectomy. The procedure seems to be safer for women under 45 years of age.
Surgeon‐Performed Ultrasound for Preoperative Localization of Abnormal Parathyroid Glands in Patients with Primary Hyperparathyroidism
Authors: Kairys John C. , Daskalakis Constantine , Weigel Ronald J.
Published: July 2006

Background

The introduction of portable ultrasound equipment enables surgeons to perform ultrasound examinations in a clinic setting. This study was undertaken to evaluate surgeon‐performed ultrasound (SP‐US) in patients with primary hyperparathyroidism (PHPT).

Methods

Between July 2003 and March 2004, 65 patients with PHPT were evaluated with SP‐US and 48 of these patients underwent parathyroid surgery. Among this group of 48 evaluable patients, 47 had preoperative imaging with technetium‐99m sestamibi scanning (MIBI), and 12 had an additional ultrasound examination at an external radiology department (RP‐US).

Results

All patients were cured of PHPT and the operative findings were used to determine the true status of the parathyroid glands of each patient. Twenty‐four (50%) patients had concomitant thyroid nodules which were identified by SP‐US, and 4 (8.3%) patients had simultaneous thyroid operations, 2 of which were for thyroid cancer. Considering data for all patients, SP‐US had significantly higher sensitivity than MIBI or RP‐US (60% vs. 46%, P = 0.013, and 60% vs. 11%, P = 0.004 respectively). Among the patients with a single adenoma, SP‐US, MIBI, and RP‐US had sensitivities of 83%, 63%, and 13% respectively. The specificities of all three imaging techniques were uniformly high and were not significantly different from each other.

Conclusions

Surgeon‐performed ultrasound is an accurate modality for localizing abnormal parathyroid glands in patients with PHPT, with results that compare favorably with other parathyroid imaging modalities.
Pancreaticoduodenectomy with Mesentericoportal Vein Resection for Adenocarcinoma of the Pancreatic Head
Authors: Carrère Nicolas , Sauvanet Alain , Goere Diane , Kianmanesh Reza , Vullierme Marie‐Pierre , Couvelard Anne , Ruszniewski Philippe , Belghiti Jacques
Published: July 2006

Background

The value of mesentericoportal vein resection (VR) associated with pancreaticoduodenectomy (PD) for pancreatic‐head adenocarcinoma still remains controversial.

Methods

From 1989 to 2003, 45 consecutive patients with pancreatic‐head adenocarcinoma underwent PD with mesentericoportal VR due to intraoperative macroscopic involvement of the superior mesenteric or portal vein (VR+ group). They were compared with 88 patients who underwent PD for adenocarcinoma without VR over the same time period (VR− group) and matched for age, American Society of Anesthesiologists (ASA) score, pathological diagnosis, and nodal involvement. Preoperative features, intraoperative parameters, postoperative course, and survival were compared between the VR+ group and VR− group. Factors that may influence survival were determined by univariate and multivariate analyses.

Results

Mortality, morbidity, and mean hospital stay did not differ between the two groups (VR+ 4.4%, 56%, and 22.6 days, respectively; VR− 5.7%, 64%, 24.6 days, respectively). In the group VR+, vein invasion was histologically proven in 29 (64%) patients. Three‐year global survival and 3‐year disease‐free survival did not differ between the two groups: VR+ 22% and 14%, respectively; VR− 25% and 21%, respectively (log‐rank: P = 0.69 and P = 0.39, respectively). Neither VR nor histologically proven vein involvement significantly impacted survival duration. On multivariate analysis, tumor‐free margin was the most important prognostic factor.

Conclusions

Vein resection during PD can be performed safely. Patients with adenocarcinoma who require VR during PD have a survival not different from that of patients who undergo standard PD. Macroscopic isolated mesentericoportal vein involvement is not a contraindication for PD in patients with adenocarcinoma provided disease‐free margins can be obtained.
Isolation and Characterization of the First Putative Peroxidase Gene from Oilseed Rape (Brassica napus) which is Highly Homologous to HRPC
Authors: Wu Weisheng , Lu Jie , Wei Yamin , Wang Jin , Lin Juan , Cao Shuwen , Sun Xiaofen , Tang Kexuan
Published: July 2006

A new gene, designated as BnPrx (GenBank Accession No. DQ078754), was isolated from oilseed rape (Brassica napus) by SMART Rapid Amplification of cDNA Ends (RACE). The full-length cDNA is 1307 bp long and contains a 1062 bp open reading frame (ORF), which encodes a 354 amino acid peroxidase precursor, with a 31 aa N-terminal signal peptide and a 15 aa C-terminal propeptide. The putative protein has a molecular weight of 38.86 kDa and a calculated pI of 5.85. BnPrx shares high identity with HRPC (89%). BnPrx possesses all active residues and two Ca2+ sites present in Horseradish peroxidase isoenzymes C (HRPC) as well as six N-glycosylation sites. The predicted 3-D structure of BnPrx is very similar to that of HRPC. Assisted by genomic walking technology, the genomic DNA of BnPrx was also cloned, consisting of 3 introns and 4 exons. Thirty-two TATA boxes, 18 CAAT boxes and many cis-elements, such as WUN, MeJR, were found in its promoter region. Southern blot analysis indicated that BnPrx belonged to a small gene family. Northern blot analysis revealed that BnPrx was constitutively expressed in all tested tissues, including roots, stems and leaves, with the high expression in leaves and stems. The expression of BnPrx could be induced by methyl jasmonate (MeJA), salicylic acid (SA), cold and H2O2. The cloning and characterizing of BnPrx might not only help us understand the physiological function and molecular evolution of the large peroxidase gene family more comprehensively, but also provide an alternative way of seeking a more effective and economical substitute for HRPC.
Pleistocene Glaciation in the Southern Lake District of Chile
Authors: Porter Stephen C.
Published: July 2006

Relative-age criteria permit deposits of successive Andean glacier advances in the southern Lake District of Chile to be divided into four mappable drift sheets, the oldest two of which overlie Tertiary bedrock along the eastern flank of the Cordillera de la Costa. Only the youngest drift (Llanquihue) is datable by radiocarbon. During the most extensive ice advance of the last glaciation the Lago Llanquihue glacier was about 95 km long and reached an estimated maximum thickness of between 1000 and 1300 m. Glacier equilibrium lines at that time lay about 1000 m below their present level and rose eastward with a gradient of about 5 m/km. Successive ice advances in the Lago Llanquihue basin, which resulted in construction of end moraines and associated outwash plains beyond the lake margin, culminated sometime before about 20,000 yr ago and between 20,000 and 19,000 yr ago. A later readvance, inferred from the sedimentary record of lake-level fluctuations in the basin, had begun by about 15,000 yr ago and culminated shortly after 13,000 yr ago. A comparable, but less-closely dated, record of ice advances is found northwest of Seno Reloncaví and on Isla Chiloé. Deglaciation following the latest advance is likely to have been rapid, for the major glacier lobes fronted on deep water bodies that would have promoted extensive calving.
Mineralogy and Phase Chemistry of Mount St. Helens Tephra Sets W and Y as Keys to Their Identification
Authors: Smith Diane R. , Leeman William P.
Published: July 2006

Voluminous and widespread tephras were produced frequently during the last 36,000 yr of volcanic activity at Mount St. Helens. Numerous tephra sets have been defined by D. R. Mullineaux, J. H. Hyde, and M. Rubin (1975, U.S. Geological Survey Journal of Research, 3, 329–335) on the basis of field relations, Fe–Mg phenocryst assemblage, and 14C chronology and are valuable marker beds for regional stratigraphic studies. In this study modal abundances and mineral compositions were determined (via petrographic and electron microprobe techniques) for numerous samples of individual layers within tephra sets W and Y to evaluate the degree of compositional variability within and between tephra layers and criteria by which to distinguish among Mount St. Helens and other Pacific Northwest tephras. Although individual layers within a set (e.g., We, Wn) cannot be distinguished from each other on the basis of mineralogic characteristics examined, mineral compositions allow distinction among layers W and Y and other Pacific Northwest tephras (e.g., Mazama, Glacier Peak). Fe–Ti oxide compositions and T–fO2 estimates derived using coexisting magnetite—ilmenite are especially useful due to the compositional homogeneity of these minerals both within and between samples of a given unit over a wide geographic area. The silicates show more compositional variability than the oxides, but SiO2/Al2O3 contents in hornblende and Fe/Mg ratios in hypersthene aid in distinguishing among Pacific Northwest tephras.
Changes During the Holocene in the Size of White-Tailed Deer (Odocoileus virginianus) from Central Illinois
Authors: Purdue James R.
Published: July 2006

White-tailed deer (Odocoileus virginianus) from central Illinois varied in size during the Holocene. The record, which extends back to 8450 yr B.P., indicates small deer through the mid-Holocene until 3650 yr B.P., after which size increases. Although influences of winter climate, seasonality, anthropogenic effects, and other ecological factors should not be discounted, an intriguing possible cause of the deer size shifts is insolation-driven summer climate and its influence on food resources. In the Holocene, small deer size is correlated with high summer insolation and with low winter insolation. Climatic models indicate that in spite of changes in insolation, Holocene winters did not vary greatly through time, especially in contrast to summers, which were dynamic. Physiological constraints peculiar to O. virginianus make critical the quality of summer forage for determining final adult size. Summer temperature averaged 2°C warmer than present during the middle Holocene, which increased evaporation and probably reduced the period of availability of high-quality forage low in fiber and high in protein. Consequently, less fuel for growth was consumed by mid-Holocene deer and only small body size was achieved. Other possible causes (e.g., Bergmann's rule, seasonality) of clinal variation are considered with reference to central Illinois deer, but at present the most parsimonious explanation appears to be the summer insolation hypothesis.
Coseismic Uplift of Holocene Marine Terraces in the Pakarae River Area, Eastern North Island, New Zealand
Authors: Ota Yoko , Hull Alan G. , Berryman Kelvin R.
Published: July 2006

Holocene marine terraces along 15 km of the northeastern coast of North Island record episodic tectonic uplift. A maximum of seven terraces are arranged in staircase fashion and lie about 20 km above the subduction interface between the Pacific and Australian plates. The highest (T1) corresponds with the maximum of the Holocene marine transgression about 6700 14C yr B.P. Younger terraces are marine abrasion platforms overlain by thin beach deposits. Radiocarbon ages of marine shells from beach deposits indicate that uplift above marine conditions occurred ca. 6700(T1), 5500(T2), 3900(T3), 2500(4), 1600(T5), 1000(T6), and slightly younger than 600(T7) yr B.P. Uplift probably occurred coseismically. The maximum late Holocene uplift rate in the study area is 8 mm/yr. Altitudinal distribution of terraces suggests deformation exists as a ca. 20-km elongate dome, broken at the southern end by the Pakarae fault, which trends across the dome. Rupture on this fault has accompanied the growth of the dome but is not responsible for it. Bathymetric profiling suggests that an active fault, parallel to and about 5 km offshore, is probably responsible for the episodic coastal uplift.
Environmental Change in the Yangtze River Delta Since 12,000 Years B.P.
Authors: Liu Kam-Biu , Sun Shuncai , Jiang Xinhe
Published: July 2006

A 52-m core from Qidong at the tip of the Yangtze River (Chang Jiang) delta provides a history of sea-level change, deltaic development, and vegetational and climatic changes during the last 12,000 yr. About 12,000 yr ago, when sea level was about 60 m below the present level, the coring site was situated in the innermost part of the exposed continental shelf. The late-Pleistocene vegetation on the uplands of the Lower Yangtze River valley was a mixed forest of deciduous and broadleaved evergreen trees in which Betula, Ulmus, Tsuga, and Cupressaceae were slightly more abundant than at present. Abies and Picea were probably present as relict populations on mountains bordering the region. Rapidly rising sea level converted the Qidong area to a coastal or estuarine environment between 11,000 and 10,800 yr B.P., leading to widespread development of wetlands dominated by Gramineae and Cyperaceae. During the next 2500 yr coastal erosion due to marine transgression obliterated the sedimentary record. Deltaic sedimentation predominated from 8300 to 3800 yr B.P., as the Yangtze River delta prograded by successively building a series of estuarine sand bars. During the mid-Holocene, the climate was slightly warmer and more humid than at present, allowing the subtropical broadleaved evergreen trees to increase their populations. Pinus and Quercus became more abundant after 3800 yr B.P. in response to climatic cooling. The present deltaic plain in Qidong formed less than 200 yr ago.
Brief Report: School exclusion drug use and delinquency in adolescence
Authors: McCrystal Patrick , Higgins Kathryn , Percy Andrew
Published: July 2006

Fifty‐one young people aged 14–15 years considered to be at a high risk to substance abuse and exhibiting antisocial behavior, primarily because they longer attended mainstream school, participated in this research by completing a questionnaire to measure drug use and delinquent behaviour. The findings suggest that many of them may have already developed a high propensity to drug abuse and antisocial behaviour compared with their peers in mainstream education. As they were all excluded from school, they were not accessing school based prevention programmes delivered to their contemporaries at school suggesting that additional and specialized resources are required to fully meet their needs.
Mono‐ and dicotyledonous plant‐specific RNA editing sites are correctly edited in both in organello systems
Authors: Bolle Nina , Kempken Frank
Published: July 2006

We set out to analyse the phylogenetic distribution of cox2 RNA editing sites. Database searches have revealed the presence of mono‐ and dicotyledonous‐specific RNA editing sites. Therefore, to better understand tRNA editing system in plants, we developed a new dicotyledonous in organello RNA editing system using cauliflower mitochondria and analysed the transcription of the cox2 gene for both maize and Arabidopsis. These results were compared with those obtained from a maize mitochondrial in organello system. Surprisingly, both the mono‐ and dicotyledonous cox2 transcripts were efficiently edited in the mitochondrial cauliflower and maize in organello systems, respectively, even for RNA editing sites not present in the endogenous cox2 sequences. Taken together, our observations support a self‐guiding‐transcript model for RNA editing in higher plants.
Human and mouse hemoglobin association with the transgenic mouse erythrocyte membrane
Authors: Chen Qiuying , Balazs Tania C. , Nagel Ronald L. , Hirsch Rhoda Elison
Published: July 2006

Transgenic mouse models of hemoglobinopathies unravel pathophysiological mechanisms; yet the validity of the red blood cell (RBC) model of human hemoglobin (hHb) enveloped by a mouse (m) membrane has been questioned. Isoelectric focusing of hHb and mHb from transgenic mRBC shows a greater association of mHb to the mouse membrane compared to normal hHbA, supporting a species‐specific Hb‐mRBC membrane interaction. Enhanced hmutant Hb (HbE, HbS and HbC)‐mRBC membrane affinities correlates with enhanced membrane lipid peroxidation and parallel those reported in hRBC, lending support to transgenic mRBC as models of hemoglobinopathies. Species‐specific Hb‐membrane interaction may be overridden by Hb charge and conformational alterations.
Improving emergency obstetric care in Mozambique: The story of Sofala
Authors: Santos C. , Diante D. , Baptista A. , Matediane E. , Bique C. , Bailey P.
Published: July 2006

Objective: The 5‐year project in the province of Sofala was designed to improve access, quality and utilization of emergency obstetric care (EmOC) by strengthening rural hospitals and health centers and ultimately the health system's capacity to respond to emergencies more quickly and effectively. Methods: Implementation consisted of attention to infrastructure, human resource development, transportation and communication systems, and management. Specific management aspects that were targeted for improvement included: supportive supervision, logistics for supplies, equipment and drugs, record keeping, monitoring and evaluation, and quality improvement techniques such as maternal death audits. Results: Access to EmOC improved with an increase in the number of fully functional EmOC facilities from 4 to 18. The number of women with obstetric complications who were admitted for treatment in participating facilities tripled, and the proportion of those women dying declined by half. Conclusions: Close collaboration and partnership with the provincial health directorate make the sustainability of many results likely while the replication of much of the Sofala model to other provinces is promising for the national strategy to reduce maternal mortality.
Proximal ureteral ectopia causing hydronephrosis in a kitten
Authors: D'Ippolito Paola , Nicoli Stefano , Zatelli Andrea
Published: July 2006

A 2-month-old, female cat was presented for abdomen dilation. The patient was undernourished, and severe left hydronephrosis was diagnosed after clinical, ultrasonographical and radiographical examination. Although pyelography was performed in order to visualise the ureteral course, surgery was necessary to reach a final aetiological diagnosis and treatment. At gross examination, the left ureter crossed the renal capsula at the level of the caudal renal pole, and the subcapsular ureteral segment was markedly dilated. Distal to the renal capsula, the left ureter was very thin when compared to the right. The parenchyma of the left kidney, as suggested by ultrasonographical evaluation, was extremely reduced in thickness. An ureteronephrectomy was performed. Histopathological evaluation revealed glomerular sclerosis and diffuse parenchymal fibrosis. Severe hydronephrosis derived from an altered renal pelvic anatomy and abnormal ureteral course determining functional stenosis. Diagnosis of congenital anomaly before development of complications such as hydronephrosis could have allowed a surgical renal capsulectomy and obstruction relief. To the author's knowledge, this is the first report of severe hydronephrosis associated to altered renal pelvic anatomy and proximal ureteral ectopia in cat.
Why do Internet commerce firms incorporate logistics service providers in their distribution channels?
Authors: Rabinovich Elliot , Knemeyer A. Michael , Mayer Chad M.
Published: July 2006

The Internet has redefined information‐sharing boundaries in distribution channels and opened new avenues for managing logistics services. In the process, firms have started to incorporate new service providers in their commercial interactions with customers over the Internet. This paper studies conceptually and empirically why Internet commerce firms (ICFs) have established relationships with these providers. Focusing on logistics services in outbound distribution channels, we rely on transaction cost theory to reveal that low levels of asset specificity and uncertainty drive Internet commerce firms to establish these relationships. Moreover, we apply strategic network theory to show that Internet commerce firms seek these providers because they offer access to relationship networks that bundle many complementary logistics services. In addition, logistics service providers make these services available across new and existing relationships between the Internet commerce firms, their customers, and their vendors.
Posterior fossa arachnoid cyst presenting with isolated sensorineural hearing loss
Authors: Thinakara-Rajan T , Janjua A , Srinivasan V
Published: July 2006

Arachnoid cysts are benign cysts occurring in the intra-arachnoid space and containing cerebrospinal fluid. They constitute approximately 1 per cent of all intracranial masses. They are uncommon in the posterior cranial fossa. Common presenting symptoms include headaches, seizures, focal neurologic signs and vague dizziness. Magnetic resonance imaging is the preferred method of investigation, and the treatment for symptomatic cysts is generally surgical drainage.

We report the unusual presentation of a young patient with a posterior fossa arachnoid cyst that manifested in the form of isolated unilateral sensorineural hearing loss. The patient underwent posterior fossa craniotomy and marsupialization of the cyst. To our knowledge, posterior fossa arachnoid cyst presenting with isolated hearing loss alone has not been reported in the English literature. A review of the literature pertaining to posterior fossa arachnoid cysts, including the clinical features, diagnosis and management, is also presented.
We Will No Longer Be Servile: Aprismo in 1930s Ayacucho
Authors: HEILMAN JAYMIE PATRICIA
Published: July 2006

This article challenges the notion that the APRA party's poor electoral showings in Peru's southern sierra during the 1930s reflected regional lack of interest in the party and that APRA held little appeal for indigenous peasants. Focusing on two rural districts in the department of Ayacucho, the article reveals that APRA was indeed a formidable presence in rural Ayacucho during the 1930s. With its calls for regional inclusion and decentralisation, APRA appealed to progressive hacendados, schoolteachers and even wealthy peasants, who linked APRA's national discourses to their local struggles for political power and land.
Designing Freedom, Regulating a Nation: Socialist Cybernetics in Allende's Chile
Authors: MEDINA EDEN
Published: July 2006

This article presents a history of ‘Project Cybersyn’, an early computer network developed in Chile during the socialist presidency of Salvador Allende (1970–1973) to regulate the growing social property area and manage the transition of Chile's economy from capitalism to socialism. Under the guidance of British cybernetician Stafford Beer, often lauded as the ‘father of management cybernetics’, an interdisciplinary Chilean team designed cybernetic models of factories within the nationalised sector and created a network for the rapid transmission of economic data between the government and the factory floor. The article describes the construction of this unorthodox system, examines how its structure reflected the socialist ideology of the Allende government, and documents the contributions of this technology to the Allende administration.
Contact tracing strategies in heterogeneous populations
Authors: EAMES K. T. D.
Published: July 2006

Contact tracing is a well-established disease control measure that seeks to uncover cases by following chains of infection. This paper examines mathematical models of both single-step and iterative contact tracing schemes and analyses the ability of these procedures to trace core groups and the sensitivity of the intervention to the timescale of tracing. An iterative tracing process is shown to be particularly effective at uncovering high-risk individuals, and thus it provides a powerful public health tool. Further targeting of tracing effort is considered. When the population exhibits like-with-like (assortative) mixing the required effort for eradication can be significantly reduced by preferentially tracing the contacts of high-risk individuals; in populations where individuals have reliable information about their contacts, further gains in efficiency can be realized. Contact tracing is, therefore, potentially an even more potent tool than its present usage suggests.
The ‘Chechen Problem’: Handling an Awkward Legacy, 1918–1958
Authors: WERTH NICOLAS
Published: July 2006

The study of the ‘Chechen problem’ from the civil war period to the aftermath of the 20th Congress of the CPSU highlights a major topic in recent historiography of the Soviet period: the resistance to the regime. The various ways in which the Chechens resisted sovietisation over several decades provide a fine illustration of the highly complex notion of ‘social resistance’ in the Soviet Union. In the Chechen case, the manifestation and expression of resistance were rooted either in deeply ingrained social identities, community and tradition or in national and universal strategies of popular collective action. But the ‘Chechen problem’ also provides a good example of the different reactions and policies of the Soviet state when faced with this kind of ‘multi-dimensional’ resistance. These policies changed and evolved over the years: armed operations aimed at the ‘eradication of Chechen banditry’ in the 1920s and 1930s, total deportation in 1944 and, after 1956, the removal of most of the limitations imposed on the ‘punished’ national group.
Einfluss des Fähigkeitsselbstkonzepts auf die Intelligenz- und Konzentrationsleistung
Authors: Eckert Carolin , Schilling Daniela , Stiensmeier-Pelster Joachim
Published: July 2006

Zusammenfassung. In zwei laborexperimentellen Studien wurde der Einfluss des Fähigkeitsselbstkonzepts auf Testleistung in Abhängigkeit davon untersucht, ob vor bzw. während der Aufgabenbearbeitung Erfolg oder Misserfolg erlebt wurde. In Studie 1 bearbeiteten 70 Studierende den Konzentrations-Belastungstest d2, nachdem sie zuvor Erfolg oder Misserfolg in einem Gedächtnistest hatten. In Studie 2 bearbeiteten 55 Studierende Zahlenreihenaufgaben aus einem Intelligenztest, wobei die Hälfte zu Beginn der Aufgabenbearbeitung mit Misserfolg konfrontiert wurde. Vor beiden Experimenten wurde das Fähigkeitsselbstkonzept über Fragebogen erhoben. Es zeigte sich in beiden Studien, dass nach Misserfolg Probanden mit niedrigem Fähigkeitsselbstkonzept eine signifikant schlechtere Leistung erbrachten als Personen mit hohem Fähigkeitsselbstkonzept und als Personen mit niedrigem Fähigkeitsselbstkonzept, die keinen Misserfolg erlebt hatten. Die Diskussion der Ergebnisse erfolgt im Hinblick auf die Testdiagnostik und die pädagogische Praxis.
Kommentar zum Schwerpunktthema: Entwicklung von Fähigkeitsselbstkonzepten
Authors: Filipp Sigrun-Heide
Published: July 2006

Zusammenfassung. Die Beiträge des Themenhefts werden im Hinblick auf vier Leitfragen diskutiert: Wie lässt sich die Binnenstruktur von Fähigkeitsselbstkonzepten modellieren und beschreiben? Wie lässt sich die Genese von Fähigkeitsselbstkonzepten nachzeichnen, und welche Faktoren tragen zu ihrer Modifizierbarkeit bei? Welche Auswirkungen besitzen Fähigkeitsselbstkonzepte auf künftige Leistungen, und wie werden sie umgekehrt durch Leistungsrückmeldungen beeinflusst? Inwieweit sind Fähigkeitsselbstkonzepte durch Interventionsmaßnahmen modifizierbar?
Natural marine seepage blowout: Contribution to atmospheric methane
Authors: Leifer Ira , Luyendyk Bruce P. , Boles Jim , Clark Jordan F.
Published: July 2006

The release of methane sequestered within deep‐sea methane hydrates is postulated as a mechanism for abrupt climate change; however, whether emitted seabed methane reaches the atmosphere is debatable. We observed methane emissions for a blowout from a shallow (22 m) hydrocarbon seep. The emission from the blowout was determined from atmospheric plume measurements. Simulations suggest a 1.1% gas loss to dissolution compared to ∼10% loss for a typical low‐flux bubble plume. Transfer to the atmosphere primarily was enhanced by the rapid upwelling flows induced by the massive discharge. This mechanism could allow methane suddenly released from deeper (>250 m) waters to contribute significantly to atmospheric methane budgets.
Statistical characterization of the meteor trail distribution at the South Pole as seen by a VHF interferometric meteor radar
Authors: Lau Elías M. , Avery Susan K. , Avery James P. , Janches Diego , Palo Scott E. , Schafer Robert , Makarov Nikolai A.
Published: July 2006

A VHF meteor radar system was installed at the geographical South Pole in 2001. The purpose of this system is to measure the horizontal wind field in the mesosphere–lower thermosphere (MLT) region and to understand the large‐scale dynamics of the Antarctic polar region. The radar operated for a few months in 2001 and with minor interruptions since that time. In this paper we will describe the meteor radar system, the data detection and collection process, and the postprocessing software that was developed to extract information from the meteor echoes collected with the interferometer that is part of the radar system. Finally, the main features of the meteor distribution will be presented and discussed. Our results show that the meteor activity peaks during the Antarctic summer. Furthermore, it occurs mostly in a small region around the ecliptic plane roughly ∼20° wide in terms of elevation angle spread.
Annual sea level amphidromes in the South China Sea revealed by merged altimeter data
Authors: Zhang Caiyun , Wang Bin , Chen Ge
Published: July 2006

Annual phase‐amplitude characteristics of sea level anomaly (SLA) in the South China Sea (SCS) are investigated by a merged SLA data set derived from simultaneous measurements of Envisat, Geosat‐Follow‐on (GFO), Jason‐1, and TOPEX/Poseidon (T/P) from January 2004 to December 2005. Four annual amphidromes instead of two are revealed and their locations, surrounding the Vietnam eddy, distinguish two distinctive regimes of annual variations in the SCS, a basin scale monsoon regime and a local Vietnam eddy regime. Their existence suggests that the annual amphidrome is not only a common feature on global scale, but also a phenomenon in regional seas. However, the locations of these amphidromes in the SCS vary considerably from year to year, in contrast to the annual amphidomes found in the tropical ocean basins, which are much more stable.
Reduction of surface temperature in ocean slicks
Authors: Marmorino G. O. , Smith G. B.
Published: July 2006

Airborne infrared imagery collected over the ocean reveals slicks that are 0.1° to nearly 0.4°C cooler than the surrounding water surface. These thermal contrasts are analyzed within a framework of surfactant–turbulence interaction. Slicks are shown to be a potential source of error in the remote retrieval of sea surface temperature, but a slick's thermal contrast is also a potential source of information about the ambient thermal boundary layer.
Contactless electromodulation spectroscopy of AlGaN∕GaN heterostructures with a two-dimensional electron gas: A comparison of photoreflectance and contactless electroreflectance
Authors: Kudrawiec R. , Syperek M. , Motyka M. , Misiewicz J. , Paszkiewicz R. , Paszkiewicz B. , Tłaczała M.
Published: July 2006

Photoreflectance (PR) and contactless electroreflectance (CER) spectroscopies have been applied to study optical transitions in undoped and Si-doped AlGaN∕GaN heterostructures at room temperature. Spectral features related to excitonic and band-to-band absorptions in GaN layer and band-to-band absorption in AlGaN layer have been resolved and analyzed. In addition, a broad spectral feature related to two-dimensional electron gas has been observed for the Si-doped heterostructure. It has been found that some of the mentioned optical transitions are not observed in CER spectra whereas they are very strong in PR spectra. This phenomenon is associated with different mechanisms of the modulation of built-in electric field in the investigated structure. A combination of PR and CER gives the possibility of a richer interpretation of both PR and CER spectra.
Correlating ion energies and CF2 surface production during fluorocarbon plasma processing of silicon
Authors: Martin Ina T. , Zhou Jie , Fisher Ellen R.
Published: July 2006

Ion energy distribution (IED) measurements are reported for ions in the plasma molecular beam source of the imaging of radicals interacting with surfaces (IRIS) apparatus. The IEDs and relative intensities of nascent ions in C3F8 and C4F8 plasma molecular beams were measured using a Hiden PSM003 mass spectrometer mounted on the IRIS main chamber. The IEDs are complex and multimodal, with mean ion energies ranging from 29to92eV. Integrated IEDs provided relative ion intensities as a function of applied rf power and source pressure. Generally, higher applied rf powers and lower source pressures resulted in increased ion intensities and mean ion energies. Most significantly, a comparison to CF2 surface interaction measurements previously made in our laboratories reveals that mean ion energies are directly and linearly correlated to CF2 surface production in these systems.
Phonon modes and electron-phonon interactions in cylindrical quantum wires: Macroscopic and microscopic analyses for device applications
Authors: Crouse David
Published: July 2006

The macroscopic and microscopic analyses of phonon modes that has been done in past works for two-dimensional quantum wells are developed in this work for one-dimensional quantum wires. Inconsistencies and errors in past works on phonon modes in quantum size structures are discussed including the correct form of the Lorentz factor that should be used and the proper quantization of the phonon modes. Connections between the macroscopic and microscopic approaches are described. Longitudinal optical and surface longitudinal optical phonon modes are calculated. The free polarization Hamiltonian and electron-phonon interaction Hamiltonian are developed. The application of this analysis to the development of high operating temperature quantum wire infrared photodetectors is discussed.
Preparation of a hologram composed of a striped gold layer using photographic materials
Authors: Kuge Ken’ichi , Nakao Tomoaki , Goto Yoshimasa , Omatsu Takashige , Hasegawa Akira
Published: July 2006

We prepare a diffraction grating composed of the gold layer on a glass plate using the gold deposition development in photographic materials and following baking process. A high-resolution image with a spatial resolution of over 4000lines∕mm was obtained. A diffraction grating composed of gold particles in a gelatin layer was prepared by development in a gold-thiocyanate complex solution. The grating was then baked to burn out the gelatin layer and fuse the gold particles. The thickness of the grating composed of the gold layer was less than 10nm. After baking the grating had a bright gold luster and showed a clear higher-order diffraction on the reflecting side, while it showed only first-order diffraction before baking. The maximum efficiency of the first-order diffraction beam on the grating before baking was 8.8%. After baking, the maximum efficiency of the reflected diffraction beam was 1.6%. Using this method, it is possible to prepare stable holograms even in severe environments.