bluuebunny/crossref_metadata_2025 huggingface dataset:
Titanate biomaterials with enhanced antiinflammatory properties
Authors: Contreras Ramiro , Sahlin Herman , Frangos John A.
Published: September 2006

While titanium implants are generally recognized as having excellent biocompatibility, the mechanistic basis for this has yet to be established. We previously demonstrated that TiO2, found on surfaces of titanium, has antioxidant properties that degrade the reactive oxygen species (ROS) which mediate the inflammatory response. We hypothesized that the antioxidant mechanism was similar to that known to mediate photocatalysis by titanium oxides. Specifically, we investigated whether the electronic or valence state of the surface titanium atoms mediates the catalytic degradation of ROS. Surface Ti(IV) atoms in TiO2 and SrTiO3 single crystal substrates were converted into Ti(III) while maintaining the bulk crystalline structure by vacuum annealing or Niobium doping. The degradation of both chemically‐induced and neutrophil‐derived ROS were significantly increased by changing the valence state of surface titanium. These results suggest that titanium‐mediated degradation of ROS is through a catalytic mechanism. Furthermore, we describe a series of novel biomaterials that have antioxidant properties superior to those of titanium. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Opposite effect of corticosteroids and long‐acting β2‐agonists on serum‐ and TGF‐β1‐induced extracellular matrix deposition by primary human lung fibroblasts
Authors: Goulet Stephanie , Bihl Michel P. , Gambazzi Franco , Tamm Michael , Roth Michael
Published: September 2006

Asthma and chronic obstructive pulmonary disease (COPD) are characterized by chronic airway inflammation and major structural lung tissue changes including increased extracellular matrix (ECM) deposition. Inhaled corticosteroids and long‐acting β2‐agonists (LABA) are the basic treatment for both diseases, but their effect on airway remodeling remains unclear. In this study, we investigated the effect of corticosteroids and LABA, alone or in combination, on total ECM and collagen deposition, gene expression, cell proliferation, and IL‐6, IL‐8, and TGF‐β1 levels by primary human lung fibroblasts. In our model, fibroblasts in 0.3% albumin represented a non‐inflammatory condition and stimulation with 5% FCS and/or TGF‐β1 mimicked an inflammatory environment with activation of tissue repair. FCS (5%) increased total ECM, collagen deposition, cell proliferation, and IL‐6, IL‐8, and TGF‐β1 levels. In 0.3% albumin, corticosteroids reduced total ECM and collagen deposition, involving the glucocorticoid receptor (GR) and downregulation of collagen, heat shock protein 47 (Hsp47), and Fli1 mRNA expression. In 5% FCS, corticosteroids increased ECM deposition, involving upregulation of COL4A1 and CTGF mRNA expression. LABA reduced total ECM and collagen deposition under all conditions partly via the β2‐adrenergic receptor. In combination, the drugs had an additive effect in the presence or absence of TGF‐β1 further decreasing ECM deposition in 0.3% albumin whereas counteracting each other in 5% FCS. These data suggest that the effect of corticosteroids, but not of LABA, on ECM deposition by fibroblasts is altered by serum. These findings imply that as soon as airway inflammation is resolved, long‐term treatment with combined drugs may beneficially reduce pathological tissue remodeling. J. Cell. Physiol. 210: 167–176, 2007. © 2006 Wiley‐Liss, Inc.
Penicillium commune spore production in solid‐state fermentation of coffee pulp at laboratory scale and in a helical ribbons rotating reactor
Authors: Nava Isaías , Gaime‐Perraud Isabelle , Huerta‐Ochoa Sergio , Favela‐Torres Ernesto , Saucedo‐Castañeda Gerardo
Published: October 2006

Penicillium commune was grown on coffee pulp (CP) by solid‐state fermentation (SSF). The effects of the duration of CP thermal treatment and the effects of incubation temperature on spore production yield were studied at laboratory scale. The effect of mixing during fermentation was assayed at pilot plant scale in a 70 L stainless steel non‐aseptic reactor equipped with helical ribbons for mixing solids. For thermal treatments of CP at 121 °C for 10, 20, 30 and 40 min, no significant difference in spore production yield was observed. Maximum sporulation yield was found at 25 °C; when the incubation temperature was higher than 30 °C, the sporulation yield decreased significantly. A spore production yield of 3.7 × 109 spores g−1 dry CP was obtained when continuous mixing (0.25 rpm) was used at pilot plant scale; however, a decrease in spore yield (1.4 × 109 spores g−1 dry CP) was observed under static conditions. Spore production was not affected when a scale factor between 79 and 105 was assayed from laboratory to pilot plant; at this level, the productivity obtained was 3.1 × 107 spores g−1 dry CP h−1. This value is similar to that found in other reports using natural substrates but working at a smaller scale. Copyright © 2006 Society of Chemical Industry
A comparison of slurry sampling electrothermal vaporization and slurry nebulization inductively coupled plasma mass spectrometry for the direct determination of trace impurities in titanium dioxide powder
Authors: Xiang Guoqiang , Hu Bin , Jiang Zucheng , Gong Chuqing
Published: September 2006

A comparison of slurry sampling (SS)‐ETV‐ICP‐MS and slurry nebulization (SN)‐ICP‐MS for direct determination of trace impurities in titanium dioxide powder is made. The particle size effect, matrix effect and analytical characteristics of SSETV‐ICP‐MS and SN‐ICP‐MS are compared. The results have shown that SSETV‐ICP‐MS has a lower particle size effect and matrix effect compared to SN‐ICP‐MS. The analytical performance of the two methods reveals that SSETV‐ICP‐MS and SN‐ICP‐MS have similar relative detection limits (in the nanogram per liter level); however, the former has a lower absolute detection limit than the latter. Although the precision for SSETV‐ICP‐MS is a little worse than that for SN‐ICP‐MS, it is still acceptable for real sample analysis. The two methods were successfully applied for the determination of trace impurities in titanium dioxide powder samples with particle sizes of less than 50 nm, but only SSETV‐ICP‐MS could be applied for the determination of trace impurities in titanium dioxide powder samples with a particle size of 1 µm. Copyright © 2006 John Wiley & Sons, Ltd.
Carbon costs of nitrate reduction in broad bean (Vicia fabaL.) and pea (Pisum sativumL.) plants
Authors: Schilling Günther , Adgo Enyew , Schulze Joachim
Published: September 2006

The present study aimed at the assessment of carbon (C) costs for nitrate reduction by measuring the additional CO2amounts released from roots of nitrate‐fed plants in comparison with urea‐fed plants. Only roots were suitable for these determinations, because nitrate reduction in illuminated shoots is fed nearly exclusively by reducing equivalents coming directly from photosynthetic processes. Therefore, in a first experiment, the sites of nitrate reduction were determined in nodule‐free broad bean (Vicia fabaL.) and pea (Pisum sativumL.) plants grown in pots filled with quartz sand and supplied with KNO3. The extent of nitrate reduction in the various plant organs was determined by measuringin vitronitrate reductase activity andin situ15NO$ _3^- $reduction. Only between 9% and 16% of nitrate were reduced in roots of German pea cultivars, whilst 52% to 65% were reduced in broad bean roots. Therefore, C costs of the process could be determined only in broad bean, using an additional pot experiment. The C costs amounted to about 4.76 mol C (mol N)–1or 4 mg C (mg N)–1, similar to those measured earlier for N2fixation. The high proportion of nitrate reduction in shoots of pea plants implies that only very little C is required for this nitrate fraction. This can explain the better root growth of nitrate‐nourished pea plants in comparison with N2‐fixing organisms, which need C compounds for N2reduction in roots. Moreover, a different availability of photosynthates in roots of plant genotypes could explain physiologically the occurrence of “shoot and root reducers” in nature.
Genetic variation in nitrogen‐use efficiency of tef
Authors: Balcha Alemayehu , Gretzmacher Ralph , Vollmann Johann
Published: September 2006

Tef (Eragrostis tef (Zucc.) Trotter) is the ancient and most important cereal food crop of Ethiopia. A set of 20 tef genotypes was investigated in field experiments at three environments in Ethiopia to estimate genetic variation in nitrogen (N)‐use efficiency and in characters related to N accumulation as well as their relationships to grain yield. In each environment, genotypes representing both widely grown landraces and recently released cultivars were grown under three N‐fertilizer rates (0, 4, and 8 g m–2 N). In grain yield, modern cultivars were superior to landraces, whereas in other characters, differences were less clear. The variation in grain yield was significantly related to the variation in total grain N and total plant N. Grain yield weakly correlated with N‐utilization efficiency and N harvest index. Broad sense heritability was higher for grain yield, total grain N, total plant N, and N harvest index than for N‐use, N‐uptake, and N‐utilization efficiencies. The contribution of uptake efficiency to the variation in N‐use efficiency decreased from 75% to 55% and that of utilization efficiency increased from 22% to 43% at the 4 to 8 g m–2 N‐supply rate change. This study clearly suggests that tef N‐use efficiency would be increased by selecting genotypes with greater uptake efficiency at low N‐supply levels.
On the Crystal Structure of Isotactic cis‐1,4‐Poly(1,3‐pentadiene)
Authors: Napolitano Roberto
Published: September 2006

Summary: A comparison between the crystal structure of isotactic cis‐1,4‐poly(1,3‐pentadiene) previously predicted by molecular mechanics calculations and that successively determined by other authors by experimental data is reported. The agreement between the two structures is very good as far as the space group, the unit cell parameters and the conformation of the polymer chain are concerned. The mode of packing of the chains proposed in the experimental crystal structure is very similar to that found as relative minimum in the previous energy calculations. The coexistence, in different amounts, of these two modes of packing is suggested by the analysis of the simulated X‐ray spectra and by the results of new energy calculations.

A mode of packing of chains of isotactic cis‐1,4‐poly(1,3‐pentadiene).

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A mode of packing of chains of isotactic cis‐1,4‐poly(1,3‐pentadiene).
Compartmentalization in Atom Transfer Radical Polymerization (ATRP) in Dispersed Systems
Authors: Kagawa Yasuyuki , Zetterlund Per B. , Minami Hideto , Okubo Masayoshi
Published: September 2006

Summary: Compartmentalization in atom transfer radical polymerization (ATRP) in dispersed systems at low conversion (<10%) has been investigated by means of a modified Smith–Ewart equation focusing on the system n‐butyl acrylate/CuBr/4,4′‐dinonyl‐2,2′‐dipyridyl at 110 °C. Compartmentalization of both propagating radicals and deactivator was accounted for in the simulations. As the particle diameter (d) decreases below 70 nm, the polymerization rate (Rp) at 10% conversion increases relative to the corresponding bulk system, goes through a maximum at 60 nm, and thereafter decreases dramatically as d decreases further. This behavior is caused by the separate effects of compartmentalization (segregation and confined space effects) on bimolecular termination and deactivation. The very low Rp for small particles (d < 30 nm) is due to the pseudo first‐order deactivation rate coefficient being proportional to d−3.

Simulated propagating radical concentration ([P•]) as a function of particle diameter (d) at 10% conversion for ATRP of n‐butyl acrylate ([nBA]0 = 7.1 M, [PBr]0 = [CuBr/dNbpy]0 = 35.5 mM) in a dispersed system at 110 °C. The dotted line indicates the simulated [P•] in bulk at 10% conversion.

magnified image

Simulated propagating radical concentration ([P•]) as a function of particle diameter (d) at 10% conversion for ATRP of n‐butyl acrylate ([nBA]0 = 7.1 M, [PBr]0 = [CuBr/dNbpy]0 = 35.5 mM) in a dispersed system at 110 °C. The dotted line indicates the simulated [P•] in bulk at 10% conversion.
Homozygous K5Cre transgenic mice have wavy hair and accelerated malignant progression in a murine model of skin carcinogenesis
Authors: Chan Edward L. , Peace Belinda E. , Toney Kenya , Kader Sarah A. , Pathrose Peterson , Collins Margaret H. , Waltz Susan E.
Published: September 2006

Mice with conditional gene deletions have been extremely valuable in allowing investigators to study the genes of interest in a tissue‐specific manner. The Cre‐loxP recombination system provides a powerful tool to produce targeted rearrangements of particular genes. The keratin 5‐Cre recombinase (K5Cre) transgenic mouse line has been used to generate skin specific gene deletions. We found that the K5Cre mice display a unique phenotype when bred to homozygosity. The K5Cre+/+ mice have a wavy hair coat and curly whiskers. Histologically, the hair follicles appear disoriented. Over time, the K5Cre+/+ mice develop patches of alopecia. These mice are also runted when compared to wild‐type controls. Fostering the K5Cre+/+ pups to wild‐type mothers results in normal weight gain, suggesting a maternal defect in milk production. When the K5Cre+/+ mammary glands were examined, we not only found a significant decrease in the number of mammary branches in the virgin females, but also a greater number of quiescent alveoli units in the lactating glands. When the K5Cre+/+ mice were bred to v‐Ha‐ras (Tg · AC) transgenic mice, the resulting Tg · AC+/− K5Cre+/+ offspring were utilized in a chemically induced skin carcinogenesis model. The mice were treated with 2.5 µg of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) weekly for 10 wk. No difference was observed in the time to onset of papilloma formation, the number of papillomas and the average papilloma volume between the Tg · AC+/− K5Cre+/+ mice and their corresponding controls. Surprisingly, however, the K5Cre+/+ papillomas displayed an accelerated tendency to malignant progression; in addition, the frequency of malignant transformation of the papillomas is significantly enhanced. Although the K5Cre+/+ mice resemble waved‐1 and ‐2 mutants, the molecular basis for the K5Cre+/+ phenotype is probably different. In conclusion, we discovered a unique phenotype associated with the K5Cre+/+ transgenic line. © 2006 Wiley‐Liss, Inc.
Lead promotes abasic site accumulation and co‐mutagenesis in mammalian cells by inhibiting the major abasic endonuclease Ape1
Authors: McNeill Daniel R. , Wong Heng‐Kuan , Narayana Avinash , Wilson David M.
Published: September 2006

Lead is a widespread environmental toxin, found in contaminated water sources, household paints, and certain occupational settings. Classified as a probable carcinogen by the International Agency for Research on Cancer (IARC), lead promotes mutagenesis when combined with alkylating and oxidizing DNA‐damaging agents. We previously reported that lead inhibits the in vitro repair activity of Ape1, the major endonuclease for repairing mutagenic and cytotoxic abasic sites in DNA. We investigated here whether lead targets Ape1 in cultured mammalian cells. We report a concentration‐dependent inhibition of apurinic/apyrimidinic (AP) site incision activity of Chinese hamster ovary (CHO) AA8 whole cell extracts by lead. In addition, lead exposure results in a concentration‐dependent accumulation of AP sites in the genomic DNA of AA8 cells. An increase in the oxidative base lesion 8‐oxoguanine was observed only at high lead levels (500 µM), suggesting that non‐specific oxidation plays little role in the production of lead‐related AP lesions at physiological metal concentrations—a conclusion corroborated by “thiobarbituric acid reactive substances” assays. Notably, Ape1 overexpression in AA8 (hApe1‐3 cell line) abrogated the lead‐dependent increase in AP site steady‐state levels. Moreover, lead functioned cooperatively to promote a further increase in abasic sites with agents known to generate AP sites in DNA (i.e., methyl methansulfonate (MMS) and hydrogen peroxide (H2O2)), but not the DNA crosslinking agent mitomycin C. Hypoxanthine guanine phosphoribosyltransferase (hprt) mutation analysis revealed that, whereas lead alone had no effect on mutation frequencies, mutagenesis increased in MMS treated, and to a greater extent lead/MMS treated, AA8 cells. With the hApe1‐3 cell line, the number of mutant colonies in all treatment groups was found to be equal to that of the background level, indicating that Ape1 overexpression reverses MMS‐ and lead‐associated hprt mutagenesis. Our studies in total indicate that Ape1 is a member of an emerging group of DNA surveillance proteins that are inhibited by environmental heavy metals, and suggest an underlying mechanism by which lead promotes co‐carcinogenesis. Published 2006 Wiley‐Liss, Inc.†
Holmes tremor: Application of modern neuroimaging techniques
Authors: Paviour Dominic C. , Jäger H. Rolf , Wilkinson Leonora , Jahanshahi Marjan , Lees Andrew J.
Published: September 2006

Holmes tremor has a characteristic rest, intention, and postural component. The syndrome arises as a consequence of a lesion in the upper brainstem and cerebral peduncles, which, it is postulated, interrupts the cerebello‐rubrothalamic pathway. Ataxia, ophthalmoplegia, and bradykinesia are associated features. We present a case of Holmes tremor secondary to a midbrain cavernoma. Modern neuroimaging techniques in this case confirm that a combination of damage to the cerebello‐rubrothalamic pathway and the nigrostriatal pathway is required for the full Holmes tremor syndrome to occur. © 2006 Movement Disorder Society
Neuropsychological profile of DYT1 dystonia
Authors: Balas Meirav , Peretz Chava , Badarny Samih , Scott Richard B. , Giladi Nir
Published: September 2006

The common belief that primary dystonia is a purely motor disorder has recently been challenged. We examined separately the cognitive profiles of symptomatic (SYM) and nonsymptomatic (N‐SYM) groups of carriers of DYT1 mutation using a comprehensive neuropsychological test battery. Self‐report inventories of anxiety, depression, and pain levels were also administered, as well as manual motor dexterity assessment. Each group was matched with healthy controls by age, sex, mother tongue, and education. No significant differences between the SYM group to its control group were found on cognitive tests evaluating verbal and nonverbal abstract abilities, attention, information processing speed, and spatial organization. However, the SYM group showed increased verbal memory retroactive interference. Interestingly, the patients also showed higher semantic fluency performance. No significant differences between the N‐SYM group to controls were found. It was concluded that symptomatic DYT1 mutation carriers do not suffer the distinctive cognitive decline that is seen in other primary degenerative extrapyramidal disorders. © 2006 Movement Disorder Society
Prevalence of tic disorder in two schools in the Basque country: Results and methodological caveats
Authors: Linazasoro Gurutz , Van Blercom Nadège , Ortiz De Zárate Carmen
Published: September 2006

Different studies have shown that the prevalence of tic disorder is highly variable, depending on the methodology employed. The aim of this study was to determine the prevalence of tic disorder among children of two schools. The study was conducted in three successive steps: information to parents and teachers by way of speeches and projection of videotapes; anonymous fulfilling of an ad hoc questionnaire by teachers and parents and identification of children as “possible tic disorder” according to the questionnaire; and confirmation of the presence of tics by direct observation of children at school (20 minutes in each classroom). Eight hundred sixty‐seven children were included. Age ranged from 4 to 16 years. Ninety percent of parents and 99% of teachers fulfilled the questionnaire. Seventy‐one children had tics according to parents' and 50 according to teachers' opinion (both coincided in 23 cases). Fifty‐seven cases were identified after direct observation in the classroom (prevalence of 6.5%). The vast majority of tics were mild in severity and duration. Prevalence obtained in this study was comparable with data reported in studies using a similar methodology, which is higher than results shown in early studies addressed with less rigid methodology. Most of identified cases were quite mild, not leading to major functional disability. In spite of the methodology employed, it is possible that some cases were lost. © 2006 Movement Disorder Society
Ginsenoside Re promotes human sperm capacitation through nitric oxide‐dependent pathway
Authors: Zhang Hong , Zhou Qingming , Li Xiaoda , Zhao Weiping , Wang Yanling , Liu Hui , Li Ning
Published: September 2006

The regulation of sperm capacitation is important for successful fertilization. Ginsenosides, the biologically effective components of ginseng, have been found to enhance intracellular nitric oxide (NO) production and the latter has recently been indicated to play a significant role in modulation of sperm functions. We investigated the effect of Ginsenoside Re on human sperm capacitation in vitro and the mechanism by which the Ginsenosides play their roles. Spermatozoa were separated by Percoll and incubated with 0, 1, 10, or 100 µM of Ginsenoside Re. The percentages of spontaneous and lysophosphatidylcholine (LPC)‐induced acrosome reaction (AR), as a measure of sperm capacitation, were assayed with fluorescein isothiocyanate‐conjugated Pisum sativum agglutinin (FITC‐PSA). The intracellular cGMP level was measured by [3H] cGMP radioimmunoassay system. The results showed that the percentages of both spontaneous and LPC‐induced AR and intracellular cGMP level were significantly enhanced by Ginsenoside Re with a concentration‐dependent manner. Sodium nitroprusside (SNP, 100 nM), a NO donor, mimicked the effects of Ginsenoside Re. And pretreatment with a NOS inhibitor Nω‐nitro‐l‐arginine methyl ester (L‐NAME, 100 µM) or a NO scavenger N‐acetyl‐l‐cysteine (LNAC, 1 mM) completely blocked the effects of Ginsenoside Re. Furthermore, the AR‐inducing effect of Ginsenoside Re was significantly reduced in the presence of the soluble guanylate cyclase inhibitor LY83583 or cGMP‐dependent protein kinase (PCK) inhibitor KT5823, whereas addition of the cGMP analogue 8‐Br‐cGMP significantly increased the AR of human spermatozoa. Data suggested that Ginsenoside Re is beneficial to sperm capacitation and AR, and that the effect is accomplished through NO/cGMP/PKG pathway. Mol. Reprod. Dev. 74: 497–501, 2007. © 2006 Wiley‐Liss, Inc.
Change in psychological resources of younger and older cancer patients during chemotherapy
Authors: Pinquart Martin , Fröhlich Cornelia , Silbereisen Rainer K.
Published: September 2006

Psychological resources were investigated in 150 recently diagnosed adult cancer patients and in 150 healthy control group members. Before the start of chemotherapy, cancer patients reported higher levels of optimism, purpose in life than their healthy peers, and self‐esteem (only younger patients) whereas no between‐group differences emerged for internal locus of control. However, the mobilization of psychological resources was limited to younger patients, and varied by item content. Over a 9‐month period, most psychological resources of cancer patients showed a small but significant decline, and patients with higher illness‐related stressors (e.g. stronger functional impairments, low perceived success of therapy) were more likely to decline in resources. We conclude that in line with cognitive adaptation theory cancer diagnosis leads to an initial mobilization of psychological resources in younger patients, but that over the course of therapy psychological resources decline to a level that would be expected in healthy adults. Copyright © 2006 John Wiley & Sons, Ltd.
Identification of genes potentially involved in the acquisition of androgen‐independent and metastatic tumor growth in an autochthonous genetically engineered mouse prostate cancer model
Authors: Morgenbesser Sharon D. , McLaren Rajashree P. , Richards Brenda , Zhang Mindy , Akmaev Viatcheslav R. , Winter Scott F. , Mineva Nora D. , Kaplan‐Lefko Paula J. , Foster Barbara A. , Cook Brian P. , Dufault Michael R. , Cao Xiahong , Wang Clarence J. , Teicher Beverly A. , Klinger Katherine W. , Greenberg Norman M. , Madden Stephen L.
Published: September 2006

BACKGROUND

A major focus of prostate cancer research has been to identify genes that are deregulated during tumor progression, potentially providing diagnostic markers and therapeutic targets.

METHODS

We have employed serial analysis of gene expression (SAGE) and microarray hybridization to identify alterations that occur during malignant transformation in the Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) model. Many of these alterations were validated by real‐time PCR (rtPCR).

RESULTS

We identified several hundred mRNAs that were deregulated. Cluster analysis of microarray profiles with samples from various stages of the disease demonstrated that androgen‐independent (AI) primary tumors are similar to metastases; 180 transcripts have expression patterns suggesting an involvement in the genesis of late‐stage tumors, and our data support a role for phospholipase A2 group IIA in the acquisition of their highly aggressive characteristics.

CONCLUSIONS

Our analyses identified well‐characterized genes that were previously known to be involved in prostate cancer, validating our study, and also uncovered transcripts that had not previously been implicated in prostate cancer progression. Prostate 67:83–106, 2007. © 2006 Wiley‐Liss, Inc.
Theoretical study of XCN− (XF,Cl) anions
Authors: Bhattacharyya I. , Bera N. C. , Das A. K.
Published: October 2006

Geometrical parameters, vibrational frequencies, zero‐point energy, dipole moment, NBO atomic charges of FCN−, ClCN− and their isomers, and the isomerization energy of FCN− and ClCN− are studied in detail using the ab initio MP2, CCSD, CCSD(T), and density functional B3LYP methods. The results are compared with the existing data reported using various theoretical methods in conjunction with different basis sets. The effect of electron correlation on the structural properties of these molecular anions is discussed. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Sequential Reactions with Amine‐Terminated Monolayers and Isolated Molecules on H/Si(111)
Authors: Eves Brian J. , Fan Chaoyang , Lopinski Gregory P.
Published: October 2006

A simple method for preparing monolayers with terminal amine functionality is demonstrated. A gas‐phase photochemical reaction of 1,3‐diaminopropane with a H‐terminated Si(111) surface results in the molecules covalently attaching to the surface, primarily through the formation of a SiN bond. These monolayers are characterized by scanning tunneling microscopy (STM) and high‐resolution electron energy loss spectroscopy (HREELS). The reactivity of the terminal amine is confirmed by exposing the monolayer to benzaldehyde, resulting in the formation of an imine link and the grafting of phenyl rings onto the surface. For short irradiation times, this reaction leads to the formation of isolated amine groups on an otherwise pristine H‐terminated surface. STM and HREELS studies of the benzaldehyde reaction on these low‐coverage surfaces (less than 0.005 monolayers) indicate that the reaction is restricted to the reactive amine groups, leaving the remainder of the surface unaffected. This simple approach for a sequential coupling reaction is expected to facilitate attachment of more complex molecules (molecular switches, biomolecules) for single‐molecule STM studies.
The mineral content of dairy cattle feed resources in Nakuru district, Kenya
Authors: Wekesa FW , Abdulrazak SA , Mukisira EA , Muia JMK
Published: September 2006

The feed resources commonly used by farmers in the Nakuru district of Kenya had mineral contents below the levels recommended for ruminants, so it was concluded that strategic mineral supplementation of rations seems necessary. Copyright © 2006 John Wiley & Sons, Ltd
Das neue ternäre Borid Mg8Pt4B und die neue intermetallische Verbindung PtMg2
Authors: Schmitt Ruth , Glaser Jochen , Meyer H.‐Jürgen
Published: October 2006

The New Ternary Boride Mg8Pt4B and the New Intermetallic Compound PtMg2

The new magnesium platinum boride Mg8Pt4B was obtained from a reaction of the elements in sealed niobium tubes. It crystallizes isotypically with Mg8Rh4B in the cubic space group $Fd{\bar 3}m$ with a =12.2481(1) Å and can be structurally derived from the Ti2Ni structure type, where boron occupies cavities, which are formed by four magnesium and four platium atoms. The new intermetallic compound PtMg2 was also prepared by reaction of the elements in a sealed Nb container and adopts the tetragonal CuAl2 type structure, space group I4/mcm with a = 6.334(1) Å and c = 5.621(1) Å.
Halide Abstraction by Na[B{C6H3(CF3)2‐3,5}4]: Synthesis and Structural Characterization of the Rhodium(I) Cations [(η6‐arene)Rh(PPh3)2]+ (Arene = benzene, toluene)
Authors: Buttler Oliver , Al‐Fawaz Amal , Kays Deborah L. , Day Joanna K. , Ooi Li‐Ling , Aldridge Simon
Published: October 2006

Halide abstraction from [(Ph3P)2Rh(μ‐Cl)]2 by the sodium salt of the weakly coordinating [BArf4]− anion [Arf = C6H3(CF3)2‐3,5] in the presence of excess arene offers a convenient, high‐yielding route to the half‐sandwich cations [(arene)Rh(PPh3)2]+[BArf4]− [arene = benzene (1), toluene (2)]. Crystalline samples of 1 and 2 are isomorphous [a = 13.1270(2), b = 15.3030(2), c = 17.5760(3) Å, α = 74.620(1), β = 81.533(1), γ = 88.540(1)° for 1] and feature the arene ligand bound to the rhodium atom in η6 fashion.
The Code of Ethics of The National Society of Genetic Counselors
Authors:   National Society of Genetic Counselors
Published: September 2006

This document is the revised Code of Ethics of the National Society of Genetic Counselors that was adopted in January 2006 after majority vote of the full members of the NSGC. The explication of the revisions is published in this volume of the Journal of Genetic Counseling. This is the third revision to the Code of Ethics since its original adoption in 1992.
Contemporary medical therapy for polycystic ovary syndrome
Authors: Lanham M.S.M. , Lebovic D.I. , Domino S.E.
Published: September 2006

Polycystic ovary syndrome is a multi‐system endocrinopathy with long‐term metabolic and cardiovascular health consequences. Patients typically present due to symptoms of irregular menstruation, hair growth, or infertility; however, recent management options are aimed at further treating underlying glucose–insulin abnormalities as well as androgen excess for proactive control of symptoms. By a 2003 international consensus conference, diagnosis is made by two out of three criteria: chronic oligoovulation or anovulation after excluding secondary causes, clinical or biochemical evidence of hyperandrogenism (but not necessarily hirsutism due to inter‐patient variability in hair follicle sensitivity), and radiological evidence of polycystic ovaries. Traditional medical treatment options include oral contraceptive pills, cyclic progestins, ovulation induction, and anti‐androgenic medications (aldosterone antagonist, 5α‐reductase antagonist, and follicle ornithine decarboxylase inhibitor). Recent pharmacotherapies include insulin‐sensitizing medications metformin and two thiazolidinediones (rosiglitazone/Avandia® and pioglitazone/Actos®), a CYP19 aromatase inhibitor (letrozole/Femara®), and statins to potentially lower testosterone levels.
Holocene Climate Variability and Cultural Evolution in the Near East from the Dead Sea Sedimentary Record
Authors: Migowski Claudia , Stein Mordechai , Prasad Sushma , Negendank Jörg F.W. , Agnon Amotz
Published: September 2006

A comprehensive record of lake level changes in the Dead Sea has been reconstructed using multiple, well dated sediment cores recovered from the Dead Sea shore. Interpreting the lake level changes as monitors of precipitation in the Dead Sea drainage area and the regional eastern Mediterranean palaeoclimate, we document the presence of two major wet phases (∼ 10–8.6 and ∼ 5.6–3.5 cal kyr BP) and multiple abrupt arid events during the Holocene. The arid events in the Holocene Dead Sea appear to coincide with major breaks in the Near East cultural evolution (at ∼ 8.6, 8.2, 4.2, 3.5 cal kyr BP). Wetter periods are marked by the enlargement of smaller settlements and growth of farming communities in desert regions, suggesting a parallelism between climate and Near East cultural development.
London, Barbican
Authors: Anderson Martin
Published: October 2006

London, Barbican: Salonen's ‘Wing on Wing’
‘Lulu’ in English
Authors: Rickards Guy
Published: October 2006

BERG Opera: Lulu. Lisa Saffer (sop), Susan Parry (mezzo), Robert Hayward (bar), John Graham-Hall (ten), Gwynne Howell (bass), Robert Poulton (bar), Stuart Kale (ten), Anna Burford, Graeme Danby (bass), Alan Oke (ten), Roger Begley (bass), Claire Mitcher (sop), Paul Napier-Burrows (bass), Jane Powell (mezzo), Moira Harris (sop), Toby Stanford-Allen (bar). English National Opera Orchestra c. Paul Daniel. Chandos Opera In English CHAN 3130 (3-CD set).
St Albans Abbey
Authors: Barlow Jill
Published: October 2006

St Albans Abbey: Joseph Phibbs's ‘Tenebrae’
Recent Ned Rorem CDs
Authors: Johnson Bret
Published: October 2006

ROREM: Flute Concerto; Violin Concerto; Pilgrims for strings. Philippe Quint (vln), Jeffrey Khaner (fl), Royal Liverpool Philharmonic Orchestra c. José Serebrier. Naxos American Classics 8.559278.

ROREM: The Auden Songs; The Santa Fe Songs. Christopher Lemmings (ten), Sara Fulgoni (mezzosop), Chamber Domaine. Black Box BBM 1104.

ROREM: Works for Choir and Organ. Harvard University Choir dir. Murray Forbes Somerville with Carson Cooman (organ). Black Box BBM 1102.
Further reviews
Authors: Rickards Guy
Published: October 2006

SESSIONS: String Quintet; Canons (to the memory of Stravinsky); 6 Pieces for solo cello; String Quartet No 1 in E minor. The Group for Contemporary Music. Naxos 8.559261.
Tropopause and hygropause variability over the equatorial Indian Ocean during February and March 1999
Authors: MacKenzie A. R. , Schiller C. , Peter T. , Adriani A. , Beuermann J. , Bujok O. , Cairo F. , Corti T. , DiDonfrancesco G. , Gensch I. , Kiemle C. , Krämer M. , Kröger C. , Merkulov S. , Oulanovsky A. , Ravegnani F. , Rohs S. , Rudakov V. , Salter P. , Santacesaria V. , Stefanutti L. , Yushkov V.
Published: September 2006

Measurements of temperature, water vapor, total water, ozone, and cloud properties were made above the western equatorial Indian Ocean in February and March 1999. The cold‐point tropopause was at a mean pressure‐altitude of 17 km, equivalent to a potential temperature of 380 K, and had a mean temperature of 190 K. Total water mixing ratios at the hygropause varied between 1.4 and 4.1 ppmv. The mean saturation water vapor mixing ratio at the cold point was 3.0 ppmv. This does not accurately represent the mean of the measured total water mixing ratios because the air was unsaturated at the cold point for about 40% of the measurements. As well as unsaturation at the cold point, saturation was observed above the cold point on almost 30% of the profiles. In such profiles the air was saturated with respect to water ice but was free of clouds (i.e., backscatter ratio <2) at potential temperatures more than 5 K above the tropopause and hygropause. Individual profiles show a great deal of variability in the potential temperatures of the cold point and hygropause. We attribute this to short timescale and space‐scale perturbations superimposed on the seasonal cycle. There is neither a clear and consistent “setting” of the tropopause and hygropause to the same altitude by dehydration processes nor a clear and consistent separation of tropopause and hygropause by the Brewer‐Dobson circulation. Similarly, neither the tropopause nor the hygropause provides a location where conditions consistently approach those implied by a simple “tropopause freeze drying” or “stratospheric fountain” hypothesis.
Modeled current and future soil thermal regime for northeast Canada
Authors: Sushama L. , Laprise R. , Allard M.
Published: September 2006

Deepening of the active layer (i.e., the seasonally thawed layer overlying permafrost) was noted since the beginning of the 1990s in northern Canada, which has already caused substantial environmental and socioeconomic consequences. There is a strong consensus among projections of climate models used to study anticipated climate changes on the rise of the global average temperatures over the next century, with maximal changes being projected for high‐latitude cold regions such as the permafrost regions. Given these projections, an evaluation of changes in the soil thermal regime becomes desirable for a number of reasons including assessments of possible ecosystem responses and impacts on man‐made infrastructures. Such an evaluation of changes in the soil thermal regime for northeastern Canada is presented in this paper using a one‐dimensional heat conduction model. Projected changes are estimated as the difference between two simulations of the soil model corresponding to the IPCC IS92a future scenario (2041–2070), which has effective CO2 concentration increasing at 1% per year (2041–2070), and current (1961–1990) climates. The surface temperature and snow cover from time series of transient climate simulations with the Canadian Regional Climate Model (CRCM) are used to drive the soil model. Results suggest significant warming trends in the annual mean, maximal and minimal near‐surface soil temperatures, with the mean annual soil surface temperature increasing by 3°–6°C for the continuous permafrost zone and by 2°–4°C for the rest of the permafrost zones in northeastern Canada. Results also suggest significant deepening of the active layer for the period 2041–2070, with its thickness increasing by more than 50% for most of the continuous permafrost region.
A simple analytical model for subauroral polarization stream (SAPS)
Authors: Lyatsky W. , Tan Arjun , Khazanov G. V.
Published: October 2006

The subauroral polarization streams (SAPS), associated with strong electric fields in the subauroral region, play an important role in energization and transporting electrons and ions in the inner magnetosphere. A new mechanism for SAPS generation is considered. The mechanism is based on a self‐consistent solution for plasma convection in nightside magnetosphere. In accordance with most researchers, we suggest that SAPS appears between the ion and electron Alfven layers in the nightside magnetosphere. However, our model for the SAPS generation does not require the ion Alfven layer to be located closer to the Earth than the electron Alfven layer. Rather the opposite, we assume that due to lower temperature of plasma‐sheet electrons, the electron Alfven layer at the nightside is located predominantly if not entirely inside the ion Alfven layer. This mechanism explains the generation of the SAPS in a wide longitudinal sector from the evening to post‐midnight, and the magnitudes of potential drop across the SAPS region and the electric field in the stream are well consistent with experimental data. We also obtained simple formulas deriving the parameters of the polarization stream.
Assessment of MODIS‐derived visible and near‐IR aerosol optical properties and their spatial variability in the presence of mineral dust
Authors: Redemann J. , Zhang Q. , Schmid B. , Russell P. B. , Livingston J. M. , Jonsson H. , Remer L. A.
Published: September 2006

Mineral dust aerosol is among the most difficult aerosol species to measure quantitatively from space. In this paper, we evaluate MODIS retrievals of spectral aerosol optical depth (AOD) from the visible to the near‐IR off the US West Coast using measurements taken by the NASA Ames Airborne Tracking Sunphotometer, AATS‐14, during the EVE (Extended‐MODIS‐λ Validation Experiment, 2004) campaign in April of 2004. In EVE, a total of 35 and 49 coincident over‐ocean suborbital measurements at the nominal level‐2 retrieval scale of 10 km × 10 km were collected for Terra and Aqua, respectively. For MODIS‐Terra about 80% of the AOD retrievals are within the estimated uncertainty, Δτ = ±0.03 ± 0.05τ; this is true for both the visible (here defined to include 466–855 nm) and near‐IR (here defined to include 1243–2119 nm) retrievals. For MODIS‐Aqua about 45% of the AOD retrievals are within Δτ = ±0.03 ± 0.05τ; the fraction of near‐IR retrievals that fall within this uncertainty range is about 27%. We found an rms difference of 0.71 between the sunphotometer and MODIS‐Aqua estimates of the visible (553–855 nm) Ångstrom exponent, while the MODIS‐Terra visible Ångstrom exponents show an rms difference of only 0.29 when compared to AATS. The cause of the differences in performance between MODIS‐Terra and MODIS‐Aqua could be instrument calibration and needs to be explored further. The spatial variability of AOD between retrieval boxes as derived by MODIS is generally larger than that indicated by the sunphotometer data.
Atmospheric collapse and transport of carbon dioxide into the subsurface on early Mars
Authors: Kurahashi‐Nakamura Takasumi , Tajika Eiichi
Published: September 2006

The present climate of Mars is extremely cold and dry, and is characterized by a very thin CO2atmosphere. On the other hand, geological evidence suggests that the Martian climate in the past might have been warm and wet, suggesting that the atmospheric CO2pressure would have been several bars higher. However, the fate of the abundant CO2is still unclear. Here we propose a possible scenario for the evolution of CO2on Mars. Numerical results suggest that CO2in the early atmosphere would have reduced by a runaway condensation to form large CO2ice caps. Then, the large CO2ice caps should have shrunk by basal melting and most of CO2has percolated into subsurface of the ice caps. The CO2would have formed clathrate hydrate and carbonate minerals, and may still reside in the subsurface of Mars. This could explain the apparent shortage of CO2on the present Martian surface.
Eruption early warning at Vesuvius: The A.D. 1631 lesson
Authors: Bertagnini Antonella , Cioni Raffaello , Guidoboni Emanuela , Rosi Mauro , Neri Augusto , Boschi Enzo
Published: September 2006

Knowledge of past precursor patterns is crucial for the correct interpretation of monitoring data and reliable volcano forecasting. In the case of Vesuvius, one of the world's riskiest volcanoes, very little information is available about unrest signals following long periods of quiescence. The translation and analysis of three Latin treatises written from eye‐witnesses immediately after the A.D. 1631 subplinian eruption allowed us to reconstruct the sequence of precursors. The progression in the signals was remarkably clear starting at least two to three weeks before the event. Widespread gas emission from the ground coupled with deformation was followed by an increase in seismic activity in the eight days before the eruption. Seismicity escalated both in frequency and intensity in the night before the eruption, heralding the opening of fissures on the volcanic cone. The details of phenomena occurring in the medium‐term (months before the eruption) are difficult to evaluate, though it is worth noticing that no major tectonic earthquakes were felt in the area of the volcano. Civil protection preparedness plans should be organized in order to complete the evacuation of people in a time span significantly shorter than the duration of expected short‐term precursors.
CD8
+
regulatory T cells generated by neonatal recognition of peripheral self-antigen
Authors: Reibke Roland , Garbi Natalio , Ganss Ruth , Hämmerling Günter J. , Arnold Bernd , Oelert Thilo
Published: September 2006

In comparison with CD4
+
regulatory T cells, the generation and function of immunomodulatory CD8
+
T cells is less well defined. Here we describe the existence of regulatory anti-K
b
-specific CD8
+
T cells that are rendered tolerant during neonatal life via antigen contact exclusively on keratinocytes. These regulatory T cells maintain tolerance during adulthood as they prevent K
b
-specific graft rejection by naïve CD8
+
T cells. Third-party immune responses remain unaffected. Up-regulation of TGF-β1 and granzyme B in the regulatory CD8
+
T cell population suggests the involvement of these molecules in common suppressive pathways shared with CD4
+
regulatory T cells. In summary, CD8
+
regulatory T cells can be induced extrathymically through antigen contact on neonatally accessible parenchymal cells and maintain tolerance throughout adult life.
NMR structural and kinetic characterization of a homeodomain diffusing and hopping on nonspecific DNA
Authors: Iwahara Junji , Zweckstetter Markus , Clore G. Marius
Published: September 2006

Nonspecific protein–DNA interactions are inherently dynamic and involve both diffusion of the protein along the DNA and hopping of the protein from one DNA molecule or segment to another. Understanding how gene regulatory proteins interact nonspecifically with DNA in terms of both structure and dynamics is challenging because the experimental observables are an ensemble average of many rapidly exchanging states. By using a variety of NMR spectroscopic techniques, including relaxation analysis, paramagnetic relaxation enhancement, and residual dipolar couplings, we have characterized structural and kinetic aspects of the interaction of the HoxD9 homeodomain with a nonspecific, 24-bp DNA duplex in a system in which the protein is not constrained to any particular site. The data reveal that HoxD9 binds to nonspecific DNA with the same binding mode and orientation as that observed in the specific complex. The mobility, however, of Arg side-chains contacting the DNA is increased in the nonspecific complex relative to the specific one. The kinetics of intermolecular translocation between two different nonspecific DNA molecules have also been analyzed and reveal that at high DNA concentrations (such as those present
in vivo
) direct transfer from one nonspecific complex to another nonspecific DNA molecule occurs without going through the intermediary of free protein. This finding provides a simple mechanism for accelerating the target search
in vivo
for the specific site in a sea of nonspecific sites by permitting more effective sampling of available DNA sites as the protein jumps from one segment to another.