bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding our Galaxy: from the center to outskirts
Authors: Shen Z. Q. , Xu Y. , Han J. L. , Zheng X. W.
Published: July 2008

We describe the efforts to understand our Milky Way Galaxy, from its center to outskirts, including (1) the measurements of the intrinsic size of the galactic center compact radio source Sgr A*; (2) the determination of the distance from the Sun to the Perseus spiral arm; and (3) the revealing of large scale global magnetic fields of the Galaxy.

With high-resolution millimeter-VLBI observations, Shen et al. (2005) have measured the intrinsic size of the radio-emitting region of the galactic center compact radio source Sgr A* to be only 1 AU in diameter at 3.5 mm. When combined with the lower limit on the mass of Sgr A*, this provides strong evidence for Sgr A* being a super-massive black hole. Comparison with the intrinsic size detection at 7 mm indicates a frequency-dependent source size, posing a tight constraint on various theoretical models.

With VLBI phase referencing observations, Xu et al. (2006) have measured the trigonometric parallax of W3OH in the Perseus spiral arm with an accuracy of 10 μas and also its absolute velocity with an accuracy of 1 km s−1. This demonstrates the capability of probing the structure and kinematics of the Milky Way by determining distances to 12 GHz methanol (CH3OH) masers in star forming regions of distant spiral arms and Milky Way's outskirts.

With pulsar dispersion measures and rotation measures, Han et al. (2006) can directly measure the magnetic fields in a very large region of the Galactic disk. The results show that the large-scale magnetic fields are aligned with the spiral arms but reverse their directions many times from the most inner Norma arm to the outer Perseus arm.
Precise measurement of the dynamical masses in AB Doradus
Authors: Guirado J. C. , Martí-Vidal I. , Marcaide J. M.
Published: July 2008

The radio stars ABDor A and ABDor B (=Rst137B) are the main components of the ABDoradus system. Both stars are double (ABDor A/ABDor C and ABDor Ba/ABDor Bb) and usual targets of astrometric instruments at optical (Hipparcos), infrared (VLT), and radio (VLBI) wavelengths. From a combination of all astrometric data available, we have obtained precise limits to the dynamical mass of both binaries in AB Doradus. The determination of the mass of ABDor C (0.090±0.003 M⊙) is important, since this object constitutes one of the few calibration points used to test theoretical evolutionary models of low-mass young stars. Follow-up observations both in radio (VLBI) and optical wavelengths (VLT) should determine with high precision the dynamical mass of the four components of this system.
Dynamics of particles in slowly rotating black holes with dipolar halos
Authors: Han W. B.
Published: July 2008

In general, the model of galaxy assumes a central huge black hole surrounded by a massive halo, disk or ring. In this paper, we investigate the gravitational field structure of a slowly rotating black hole with a dipolar halo, and the dynamics and chaos of test particles moving in it. Using Poincaré sections and fast Lyapunov indicator (FLI) in general relativity, we investigate chaos under different dynamical parameters, and find that the FLI is suitable for detecting chaos and even resonant orbits.
Stellar parameters through high precision parallaxes
Authors: Jordi C. , Fabricius C. , Carrasco J. M. , Figueras F. , Masana E. , Voss H. , Luri X.
Published: July 2008

Before Hipparcos, the determination of absolute luminosity was usually done through calibrations based on a few stellar parallaxes measured at the highest precision. The Hipparcos mission meant a giant step on the knowledge of luminosities and fine structure of the HR diagram. The Gaia mission will go an enormous step further. Besides luminosities, Gaia will allow us to derive other stellar parameters like temperature and extinction, gravity, chemical composition, age and mass by the combination of astrometric and spectrometric data. Through simulations during the mission preparation, it has been shown that the astrometric parallax information is essential to deal with the degeneracy between gravity and chemical composition ([Fe/H] and [α/Fe]), that cannot be treated using only spectrophotometry. We show the expected HR diagram for the Gaia domain and the accuracies of stellar parameters.
Astrometry course at University of Tokyo
Authors: Fukushima T.
Published: July 2008

The astrometry course at Department of Astronomy, University of Tokyo, is reviewed as an example of educational efforts for top-class students, the possible candidates of professional astronomers, in Japan. The method of teaching is unique in the sense that it gives lectures by using incomplete text books both as MS Powerpoint slides posted at a web site, http://chiron.mtk.nao.ac.jp/~toshio/education.html, and as printed materials in the form of self-study notebooks. Also there are self-study notebooks on the related issues; the courses of relativistic astrometry, of rotational motions, of numerical astronomy, and of orbital motions, the last of which is under development.
Astrometric education in China
Authors: Jin W. J. , Zhu Z.
Published: July 2008

With measuring precision on the order of milli-arcseconds for ground-based survey facilities or even micro-arcseconds for space astrometric satellites, the importance of astrometric education continues to be important. The content of astrometric courses in China during the past fifteen years is reviewed and the current astrometric courses for undergraduate and graduate students at universities and observatories in China are presented. Finally the improvements of astrometric education in content and teaching methods are suggested.
ELSA – training the next generation of space astrometrists
Authors: Lindegren L. , Bijaoui A. , Brown A. G. A. , Drimmel R. , Eyer L. , Jordan S. , Kontizas M. , van Leeuwen F. , Muinonen K. , Pourbaix D. , Torra J. , Turon C. , de Vries J. , Zwitter T.
Published: July 2008

ELSA (European Leadership in Space Astrometry) is an EU-funded research project 2006–2010, contributing to the scientific preparations for the Gaia mission while training young researchers in space astrometry and related subjects. Nine postgraduate (PhD) students and five postdocs have been recruited to the network. Their research focuses on the principles of global astrometric, photometric, and spectroscopic measurements from space, instrument modelling and calibration, and numerical analysis tools and data processing methods relevant for Gaia.
China NEO Survey Telescope and its preliminary achievement
Authors: Zhao H. B. , Yao J. S. , Lu H.
Published: July 2008

In recent years, there has been an increasing appreciation for the hazards posed by Near Earth Objects (NEOs), those asteroids and periodic comets whose motions can bring them into the Earth's neighborhood. An NEO Survey Telescope (NEOST) was built in China to be taken part in the international NEO joint survey. This telescope is a 1.0/1.2m Schmidt telescope, equipped with a 4K by 4K CCD detector with a drift-scanning function. After adjusting the telescope and test observations, in December 2006 the NEOST began its NEO survey program. We have found 188 new asteroids including an NEO – 2007 JW2 and one periodic comet –P/2007 S1 (Zhao).
Self‐Assembled Poly(butadiene)‐b‐poly(ethylene oxide) Polymersomes as Paclitaxel Carriers
Authors: Li Shuliang , Byrne Belinda , Welsh JoEllen , Palmer Andre F.
Published: July 2008

In this work, self‐assembled poly(butadiene)‐ b‐poly(ethylene oxide) (PB‐PEO) polymersomes (polymer vesicles) and worm micelles were evaluated as paclitaxel carriers. Paclitaxel was successfully incorporated into PB‐PEO polymersomes and worm micelles. The loading capacity of paclitaxel inside PB‐PEO colloids ranged from 6.7% to 13.7% w/w, depending on the morphology of copolymer colloids and the molecular weight of diblock copolymer. Paclitaxel loaded OB4 (PB219‐PEO121) polymersome formulations were colloidally stable for 4 months at 4 °C and exhibited slow steady release of paclitaxel over a 5 week period at 37 °C. Evaluation of the in vitro cytotoxicity of paclitaxel‐polymersome formulations showed that the ability of paclitaxel‐loaded polymersomes to inhibit proliferation of MCF‐7 human breast cancer cells was less compared to paclitaxel alone. By increasing the concentration of paclitaxel in polymersomes from 0.02 to 0.2 μg/mL, paclitaxel‐polymersome formulations showed comparable activity in inhibiting the growth of MCF‐7 cells. Taken together, these results demonstrate that paclitaxel‐polymersomes have desirable restrained release profile and exhibit long‐term stability.
Screening von Expansivem Problemverhalten bei Kindern im Kindergartenalter für Eltern und Erzieherinnen (PEP-Screen)
Authors: Plück Julia , Hautmann Christopher , Brix Gabriele , Freund-Braier Inez , Hahlweg Kurt , Döpfner Manfred
Published: July 2008

Zusammenfassung. Indizierte Präventionsmaßnahmen erfordern Screening-Instrumente, die Frühformen, hier expansiven Problemverhaltens (Unaufmerksamkeit, Überaktivität, Impulsivität, Aggressivität), mit möglichst geringem Aufwand erfassen. Zu diesem Zweck wurden 13 Items des Elternfragebogens über das Verhalten von Kindern und Jugendlichen (CBCL/4-18) auf der Basis verschiedener Kriterien (Trennschärfeindizes, Faktorenladungen, Itemschwierigkeit, klinische Relevanz im Expertenurteil) für einen Kurzfragebogen ausgewählt, der im Schwerpunkt expansive Verhaltensauffälligkeiten bei Kindergartenkindern im Alter von drei bis sechs Jahren auf der Basis einer Beurteiler übergreifenden Skala aus Eltern- und Erzieherurteil (EL/ER) erfassen sollte. Die Ergebnisse zur Skala Expansives Verhalten mittels explorativer Faktorenanalysen an einer kleinen Ausgangsstichprobe (NER = 597/NEL = 424) konnten mit einem konfirmatorischen Vorgehen anhand einer umfangreicheren Replikationsstichprobe (NER = 2248/NEL = 1702) bestätigt und an einer weiteren Stichprobe (NER = 599/NEL = 521) aus einem anderen Erhebungsraum überprüft werden. In der anhand des Prozentrangs 85 der beurteilerübergreifenden Skala (7 Items) indizierten Gruppe konnte bei 20% der Kinder in der nachfolgenden intensiveren Untersuchung eine Diagnose nach DSM-IV aus dem entsprechenden Bereich vergeben werden.
Verteilung des Glaubens an eine gerechte Welt in der Allgemeinbevölkerung
Authors: Schmitt Manfred , Dalbert Claudia , Montada Leo , Gschwendner Tobias , Maes Jürgen , Reichle Barbara , Radant Matthias , Schneider Angela , Brähler Elmar
Published: July 2008

Zusammenfassung. Anhand einer Erwachsenenstichprobe von N = 4686 Personen (2584 Männer, 2101 Frauen) und einer Schülerstichprobe von N = 4382 Personen (1959 Schüler, 2379 Schülerinnen) wurden Normwerte (Prozentränge, T-Werte, z-Werte) für die Skala Allgemeiner Gerechte-Welt-Glaube [GWAL; Dalbert, C., Montada, L. & Schmitt, M. (1987) . Glaube an eine gerechte Welt als Motiv: Validierungskorrelate zweier Skalen. Psychologische Beiträge, 29, 596–615.] bestimmt. In der Erwachsenenstichprobe variiert der Gerechte-Welt-Glaube mit dem Geschlecht, dem Alter, der Herkunft (Ost-West), dem Familienstand, der Schulbildung und der Erwerbstätigkeit, wobei Herkunft und Schulbildung die größten Effekte haben. Neben unspezifischen Normen für Erwachsene wurden daher auch spezifische Normen für unterschiedliche Schulbildungen (Hauptschule, Realschule/POS, Fachhochschul-/Hochschulreife) getrennt für West- und Ostdeutsche ermittelt. Während bei Schüler/innen Geschlechts- und Altersunterschiede nur schwach mit dem Gerechte-Welt-Glauben variieren, determinieren Schultyp und Klassenstufe 9% bzw. 12% der GWAL-Varianz. Deshalb wurden neben unspezifischen Normen auch spezifische Normen für verschiedene Klassenstufen (5./6. Klasse, 7./8. Klasse, 9./10. Klasse und ab 11. Klasse) getrennt für Haupt-/Realschüler/innen und Gymnasiasten ermittelt.
Zum Menschenbild von Modersohn-Becker um 1900 (in memoriam 20.11.1907)
Authors: Becker-Glauch Wulf
Published: July 2008

Zusammenfassung. Anknüpfend an den Tod und Leben vereinigenden Orakelspruch des ersten Teils 1 Musik-, Tanz- und Kunsttherapie, 18 (1), 1–16 (2007). wird versucht zu zeigen, wie dieser Leitfaden des Labyrinths in der Kunst zu verschiedenen Zeiten auftaucht und auch im Menschenbild von Paula Modersohn-Becker und in ihrer Arbeit am „Allgemeinen Menschen” (Ziegler) weiterwirkt, der durch das Individuum symbolisiert wird. Als Beispiele dienen „Die Gänsemagd” (Radierung), drei gezeichnete Frauenbildnisse, die „Frau mit Mohnblumen” (Gemälde) und die Entwicklung des Motivs „Bauernmädchen auf einem Stuhl”. Dabei ergeben sich transzendentale Spuren im Werk der Künstlerin.
County Council Politicians Attitudes Toward Suicide and Suicide Prevention
Authors: Knizek Birthe Loa , Hjelmeland Heidi , Skruibis Paulius , Fartacek Reinhold , Fekete Sandor , Gailiene Danute , Osvath Peter , Renberg Ellinor Salander , Rohrer Rudolf R.
Published: July 2008

The purpose of the present study was to compare county council politicians attitudes toward suicide and suicide prevention in five European countries. A questionnaire was distributed and here the responses to the open-ended questions are analyzed qualitatively. Considerable differences were found in what the politicians in the five countries believed to be the most important causes of suicide and how suicide can be prevented. There were also differences in to what degree the politicians revealed a judgmental attitude toward suicide, which seemed to be related to the magnitude of the problem in the respective countries. A certain implicit inconsistency in the logic directing the politicians responses was found when their views on causes to suicide and suicide prevention strategies were compared. The responses indicate a need for increased consciousness and knowledge about suicide and suicide prevention among politicians in all the five countries. This is important since they are responsible for initiating and funding suicide preventive efforts.
Years of Life Lost from Suicide in China, 1990–2000
Authors: Yip Paul S.F. , Liu Ka Y. , Law C.K.
Published: July 2008

Suicide is an important public health problem in China: It is the fifth leading cause of death in China, and suicide in China accounts for over 30% of the worlds overall suicide deaths. The substantial burden due to suicide has not been well recognized. This study aims to provide an estimate of the socioeconomic burden of the suicide problem in China in terms of years of life lost (YLL) and to discuss its implications. Suicide rates and the related YLL by age, gender, and region (urban/rural) from 1990 to 2000 were estimated using the most recent data from the Ministry of Health of China. The suicide rate in rural China was three times higher than that in urban areas. Suicide completers in rural areas shared 90% of total YLL. Rural women aged 25–39 years contributed the largest share of YLL. Our results show that some population subgroups contributed a disproportionate share to the disease burden of suicide. National strategies for suicide prevention should include targeted programs in catering the need of these specified subgroups in China.
CD45 Glycosylation controls T‐cell life and death
Authors: Earl L A , Baum L G
Published: July 2008

CD45, an abundant and highly glycosylated cell‐surface protein, is a critical regulator of T‐cell development. CD45 is differentially glycosylated throughout the life of a T cell, and the glycosylation state of CD45 controls recognition by various binding partners, affects intracellular signaling by the cytoplasmic tyrosine phosphatase domain and modulates the response of the T cell to antigen. Although the importance of CD45 during T‐cell development has been established, it is becoming increasingly clear that glycosylation of CD45 is a dynamic process that modifies T‐cell survival, activation and immune function. In this review, we address changes that occur in CD45 glycosylation during T‐cell development and differentiation, describe carbohydrate‐binding proteins that recognize differentially glycosylated forms of CD45, and discuss how differential glycosylation alters the T‐cell response to a variety of signals involved in selection, activation and apoptosis.
Ventral Posterior Complex of the Thalamus
Authors:   Allen Institute for Brain Science, Solan Beth , Ng Lydia , Morris John
Published: July 2008

This report contains a gene expression summary of the ventral posterior complex of the thalamus (VP), derived from the Allen Brain Atlas (ABA) in-situ hybridization (ISH) mouse data set. The structure’s location and morphological characteristics in the mouse brain are described using the Nissl data found in the Allen Reference Atlas. Using an established algorithm, the expression values of the VP were compared to the values of the macro/parent-structure, in this case the thalamus, for the purpose of extracting regionally specific gene expression data. The highest ranking ratios were then manually curated and verified. The 50 Select Genes were compiled for expression characterization. The experimental data for each gene may be accessed via the links provided; complementary sagittal data may also be accessed using the ABA. Correlation between gene expression in the VP and the rest of the brain, across all genes in the coronal dataset (~4300 genes), were derived computationally and are presented below. A gene ontology table (derived from DAVID Bioinformatics Resources 2007) is also included, highlighting possible functions of these 50 Select Genes.
Mg2+-dependent ATP occlusion at the first nucleotide-binding domain (NBD1) of CFTR does not require the second (NBD2)
Authors: Aleksandrov Luba , Aleksandrov Andrei , Riordan John R.
Published: July 2008

ATP binding to the first and second NBDs (nucleotide-binding domains) of CFTR (cystic fibrosis transmembrane conductance regulator) are bivalent-cation-independent and -dependent steps respectively [Aleksandrov, Aleksandrov, Chang and Riordan (2002) J. Biol. Chem. 277, 15419–15425]. Subsequent to the initial binding, Mg2+ drives rapid hydrolysis at the second site, while promoting non-exchangeable trapping of the nucleotide at the first site. This occlusion at the first site of functional wild-type CFTR is somewhat similar to that which occurs when the catalytic glutamate residues in both of the hydrolytic sites of P-glycoprotein are mutated, which has been proposed to be the result of dimerization of the two NBDs and represents a transient intermediate formed during ATP hydrolysis [Tombline and Senior (2005) J. Bioenerg. Biomembr. 37, 497–500]. To test the possible relevance of this interpretation to CFTR, we have now characterized the process by which NBD1 occludes [32P]N3ATP (8-azido-ATP) and [32P]N3ADP (8-azido-ADP). Only N3ATP, but not N3ADP, can be bound initially at NBD1 in the absence of Mg2+. Despite the lack of a requirement for Mg2+ for ATP binding, retention of the NTP at 37 °C was dependent on the cation. However, at reduced temperature (4 °C), N3ATP remains locked in the binding pocket with virtually no reduction over a 1 h period, even in the absence of Mg2+. Occlusion occurred identically in a ΔNBD2 construct, but not in purified recombinant NBD1, indicating that the process is dependent on the influence of regions of CFTR in addition to NBD1, but not NBD2.
RNA interference targeting the ACE gene reduced blood pressure and improved myocardial remodelling in SHRs
Authors: He Junhua , Bian Yunfei , Gao Fen , Li Maolian , Qiu Ling , Wu Weidong , Zhou Hua , Liu Gaizhen , Xiao Chuanshi
Published: July 2008

The purpose of the present study was to investigate the effects on blood pressure and myocardial hypertrophy in SHRs (spontaneously hypertensive rats) of RNAi (RNA interference) targeting ACE (angiotensin-converting enzyme). SHRs were treated with normal saline as vehicle controls, with Ad5-EGFP as vector controls, and with recombinant adenoviral vectors Ad5-EGFP-ACE-shRNA, carrying shRNA (small hairpin RNA) for ACE as ACE-RNAi. WKY (Wistar–Kyoto) rats were used as normotensive controls treated with normal saline. The systolic blood pressure of the caudal artery was recorded. Serum levels of ACE and AngII (angiotensin II) were determined using ELISA. ACE mRNA and protein levels were determined in aorta, myocardium, kidney and lung. On day 32 of the experiment, the heart was pathologically examined. The ratios of heart weight/body weight and left ventricular weight/body weight were calculated. The serum concentration of ACE was lower in ACE-RNAi rats (16.37±3.90 ng/ml) compared with vehicle controls and vector controls (48.26±1.50 ng/ml and 46.67±2.82 ng/ml respectively; both P<0.05), but comparable between ACE-RNAi rats and WKY rats (14.88±3.15 ng/ml; P>0.05). The serum concentration of AngII was also significantly lower in ACE-RNAi rats (18.24±3.69 pg/ml) compared with vehicle controls and vector controls (46.21±5.06 pg/ml and 44.93±4.12 pg/ml respectively; both P<0.05), but comparable between ACE-RNAi rats and WKY rats (16.06±3.11 pg/ml; P>0.05). The expression of ACE mRNA and ACE protein were significantly reduced in the myocardium, aorta, kidney and lung in ACE-RNAi rats compared with that in vehicle controls and in vector controls (all P<0.05). ACE-RNAi treatment resulted in a reduction in systolic blood pressure by 22±3 mmHg and the ACE-RNAi-induced reduction lasted for more than 14 days. In contrast, blood pressure was continuously increased in the vehicle controls as well as in the vector controls. The ratios of heart weight/body weight and left ventricular weight/body weight were significantly lower in ACE-RNAi rats (3.12±0.23 mg/g and 2.24±0.19 mg/g) compared with the vehicle controls (4.29±0.24 mg/g and 3.21±0.13 mg/g; P<0.05) and the vector controls (4.43±0.19 mg/g and 3.13±0.12 mg/g; P<0.05). The conclusion of the present study is that ACE-silencing had significant antihypertensive effects and reversed hypertensive-induced cardiac hypertrophy in SHRs, and therefore RNAi might be a new strategy in controlling hypertension.
Prevailing against Cost-Leader Competitors in the Pharmaceutical Industry
Authors: Tomer Gil
Published: July 2008

Development of a new innovative drug is costly and risky, yet offers the company protection against competition and high returns on its investment. Years after, generic products are launched and the price of the drug sharply reduces. In recent years, research-based pharmaceutical companies have deployed a tactic, deployed in consumer products markets such as razors and disposable diapers, to deal with generic competition in shape of introduction of a line-extension product for its older drug. In many cases this newer version does not carry with it enough benefits, yet gives the company fresh monopolistic protection against competition. The widespread development of line-extension drugs is replacing the development of new chemical entities. Such a reduction in true innovation slows the stream of new medications flowing into the market. In addition, line-extension switching may force customers to change to newer, more expensive products and may prevent realisation of the cost saving introduced by the generic competitors. Owing to marked differences between pharmaceuticals and other products, line-extension switching may offer no or little benefit to customers, in comparison to older drugs. While low-risk levels and future revenues make new line-extension drugs lucrative to the company, they may not contribute any proportional social benefit to society.
Expression-based screening identifies the combination of histone deacetylase inhibitors and retinoids for neuroblastoma differentiation
Authors: Hahn Cynthia K. , Ross Kenneth N. , Warrington Ian M. , Mazitschek Ralph , Kanegai Cindy M. , Wright Renee D. , Kung Andrew L. , Golub Todd R. , Stegmaier Kimberly
Published: July 2008

The discovery of new small molecules and their testing in rational combination poses an ongoing problem for rare diseases, in particular, for pediatric cancers such as neuroblastoma. Despite maximal cytotoxic therapy with double autologous stem cell transplantation, outcome remains poor for children with high-stage disease. Because differentiation is aberrant in this malignancy, compounds that modulate transcription, such as histone deacetylase (HDAC) inhibitors, are of particular interest. However, as single agents, HDAC inhibitors have had limited efficacy. In the present study, we use an HDAC inhibitor as an enhancer to screen a small-molecule library for compounds inducing neuroblastoma maturation. To quantify differentiation, we use an enabling gene expression-based screening strategy. The top hit identified in the screen was
all-trans
-retinoic acid. Secondary assays confirmed greater neuroblastoma differentiation with the combination of an HDAC inhibitor and a retinoid versus either alone. Furthermore, effects of combination therapy were synergistic with respect to inhibition of cellular viability and induction of apoptosis. In a xenograft model of neuroblastoma, animals treated with combination therapy had the longest survival. This work suggests that testing of an HDAC inhibitor and retinoid in combination is warranted for children with neuroblastoma and demonstrates the success of a signature-based screening approach to prioritize compound combinations for testing in rare diseases.
Locust retinoid X receptors: 9-
Cis
-retinoic acid in embryos from a primitive insect
Authors: Nowickyj Shaun M. , Chithalen James V. , Cameron Don , Tyshenko Michael G. , Petkovich Martin , Wyatt Gerard R. , Jones Glenville , Walker Virginia K.
Published: July 2008

The retinoid X receptor (RXR) is activated by its often elusive cognate ligand, 9-
cis
-retinoic acid (9-
cis
-RA). In flies and moths, molting is mediated by a heterodimer ecdysone receptor consisting of the ecdysone monomer (EcR) and an RXR homolog, ultraspiracle (USP); the latter is believed to have diverged from its RXR origin. In the more primitive insect,
Locusta migratoria
(Lm), RXR is more similar to human RXRs than to USPs. LmRXR was detected in early embryos when EcR transcripts were absent, suggesting another role apart from ecdysone signaling. Recombinant LmRXRs bound 9-
cis
-RA and all-
trans
-RA with high affinity (IC
50
= 61.2–107.7 nM;
K
d
= 3 nM), similar to human RXR. To determine whether specific binding had functional significance, the presence of endogenous retinoids was assessed. Embryos were extracted by using modified Bligh and Dyer and solid-phase protocols to avoid the oily precipitate that makes this material unsuitable for assay. These extracts contained retinoids (5.4 nM) as assessed by RA-inducible Cyp26A1-promoter luciferase reporter cell lines. Furthermore, the use of HPLC and MS confirmed the presence of retinoids and identified in any embryo, 9-
cis
-RA, in addition to all-
trans
-RA. We estimate that whole embryos contain 3 nM RA, including 9-
cis
-RA at a concentration of 1.6 nM. These findings strongly argue for a functional role for retinoids in primitive insects and favor a model where signaling through the binding of 9-
cis
-RA to its RXR is established relatively early in evolution and embryonic development.
Nonequilibrium generation of information in copolymerization processes
Authors: Andrieux David , Gaspard Pierre
Published: July 2008

We consider general fluctuating copolymerization processes, with or without underlying templates. The dissipation associated with these nonequilibrium processes turns out to be closely related to the information generated. This shows in particular how information acquisition results from the interplay between stored patterns and dynamical evolution in nonequilibrium environments. In addition, we apply these results to the process of DNA replication.
Identification of bacteria and bacteria-associated chemical cues that mediate oviposition site preferences byAedes aegypti
Authors: Ponnusamy Loganathan , Xu Ning , Nojima Satoshi , Wesson Dawn M. , Schal Coby , Apperson Charles S.
Published: July 2008

The yellow fever mosquito,Aedes aegypti, the global vector of dengue and yellow fever, is inexorably linked to water-filled human-made containers for egg laying and production of progeny. Oviposition is stimulated by cues from water containers, but the nature and origin of these cues have not been elucidated. We showed that mosquito females directed most of their eggs to bamboo and white-oak leaf infusions, and only a small fraction of the eggs were laid in plain water containers. In binary choice assays, we demonstrated that microorganisms in leaf infusions produced oviposition-stimulating kairomones, and using a combination of bacterial culturing approaches, bioassay-guided fractionation of bacterial extracts, and chemical analyses, we now demonstrate that specific bacteria-associated carboxylic acids and methyl esters serve as potent oviposition stimulants for gravidAe. aegypti. Elucidation of these compounds will improve understanding of the chemical basis of egg laying behavior ofAe. aegypti, and the kairomones will likely enhance the efficacy of surveillance and control programs for this disease vector of substantial global public health importance.
HDAC6 is a specific deacetylase of peroxiredoxins and is involved in redox regulation
Authors: Parmigiani R. B. , Xu W. S. , Venta-Perez G. , Erdjument-Bromage H. , Yaneva M. , Tempst P. , Marks P. A.
Published: July 2008

Eighteen histone deacetylases (HDACs) are present in humans, categorized into two groups: zinc-dependent enzymes (HDAC1–11) and NAD
+
-dependent enzymes (sirtuins 1–7). Among zinc-dependent HDACs, HDAC6 is unique. It has a cytoplasmic localization, two catalytic sites, a ubiquitin-binding site, and it selectively deacetylases α-tubulin and Hsp90. Here, we report the discovery that the redox regulatory proteins, peroxiredoxin (Prx) I and Prx II are specific targets of HDAC6. Prx are antioxidants enzymes whose main function is H
2
O
2
reduction. Prx are elevated in many cancers and neurodegenerative diseases. The acetylated form of Prx accumulates in the absence of an active HDAC6. Acetylation of Prx increases its reducing activity, its resistance to superoxidation, and its resistance to transition to high-molecular-mass complexes. Thus, HDAC6 and Prx are targets for modulating intracellular redox status in therapeutic strategies for disorders as disparate as cancers and neurodegenerative diseases.
Regulated programmed lysis of recombinant
Salmonella
in host tissues to release protective antigens and confer biological containment
Authors: Kong Wei , Wanda Soo-Young , Zhang Xin , Bollen Wendy , Tinge Steven A. , Roland Kenneth L. , Curtiss Roy
Published: July 2008

We have devised and constructed a biological containment system designed to cause programmed bacterial cell lysis with no survivors. We have validated this system, using
Salmonella enterica
serovar Typhimurium vaccines for antigen delivery after colonization of host lymphoid tissues. The system is composed of two parts. The first component is
Salmonella typhimurium
strain χ8937, with deletions of
asdA
and arabinose-regulated expression of
murA
, two genes required for peptidoglycan synthesis and additional mutations to enhance complete lysis and antigen delivery. The second component is plasmid pYA3681, which encodes arabinose-regulated
murA
and
asdA
expression and C2-regulated synthesis of antisense
asdA
and
murA
mRNA transcribed from the P22 P
R
promoter. An arabinose-regulated
c2
gene is present in the chromosome. χ8937(pYA3681) exhibits arabinose-dependent growth. Upon invasion of host tissues, an arabinose-free environment, transcription of
asdA
,
murA
, and
c2
ceases, and concentrations of their gene products decrease because of cell division. The drop in C2 concentration results in activation of P
R
, driving synthesis of antisense mRNA to block translation of any residual
asdA
and
murA
mRNA. A highly antigenic α-helical domain of
Streptococcus pneumoniae
Rx1 PspA was cloned into pYA3681, resulting in pYA3685 to test antigen delivery. Mice orally immunized with χ8937(pYA3685) developed antibody responses to PspA and
Salmonella
outer membrane proteins. No viable vaccine strain cells were detected in host tissues after 21 days. This system has potential applications with other Gram-negative bacteria in which biological containment would be desirable.
Aryl hydrocarbon receptor regulates Stat1 activation and participates in the development of Th17 cells
Authors: Kimura Akihiro , Naka Tetsuji , Nohara Keiko , Fujii-Kuriyama Yoshiaki , Kishimoto Tadamitsu
Published: July 2008

IL-17-producing T helper cells (Th17) have been recently identified as a previously undescribed subset of helper T cells. Here, we demonstrate that aryl hydrocarbon receptor (Ahr) has an important regulatory function in the commitment of Th17 cells. Ahr was robustly induced under Th17-polarizing conditions. Ahr-deficient naïve T cells showed a considerable loss in the ability to differentiate into Th17 cells when induced by TGF-β plus IL-6. We were able to demonstrate that Ahr interacts with Stat1 and Stat5, which negatively regulate Th17 development. Whereas Stat1 activation returned to its basal level in Ahr wild type naïve T cells 24 h after stimulation with TGF-β plus IL-6, Stat1 remained activated in Ahr-deficient naïve T cells after stimulation. These results indicate that Ahr participates in Th17 cell differentiation through regulating Stat1 activation, a finding that constitutes additional mechanisms in the modulation of Th17 cell development.
Egyptian reforms post-2005 and the politics of succession: implications and consequences for the future Egyptian reform process
Authors: Zahid Mohammed
Published: July 2008

Egyptian economic reforms have been an on-going process since the Egyptian government adopted liberal market reforms in 1991 (Kienle 2001, 2004), influenced by a number of internal socio-economic factors, including growing levels of poverty, heightened inflation, high levels of corruption and rising levels of unemployment, in particular among new university graduates. These factors were exerting heavy pressure on a highly bureaucratic and inefficient state (Bayat 1997). However, the ensuing economic reforms resulted in tightened fiscal and monetary polices, and a subsequent increased and heightened socio-economic crisis in Egypt, which the Egyptian government attempted to control by imposing increasingly authoritarian measures, with political de-liberalization evident in both urban and rural areas (Kienle 2001). This led, at the turn of the millennium, to a period of failed economic reforms and increased levels of authoritarianism, which coincided with the political rise of the president’s son, Gamal Mubarak, whose economic and business credentials have led to optimism concerning the possibility of future reform and change in Egypt. This paper examines the electoral promises made by Hosni Mubarak in the 2005 presidential elections and the ensuing economic and political implications for the political succession in Egypt, leading to conclusions about the future processes of economic and political reform in Egypt and the impact upon them of the political succession
The undeclared cyberspace war between Hezbollah and Israel
Authors: Al-Rizzo Hasan M.
Published: July 2008

The self explanatory title of this article adds a new dimension to the regional conflict. The use of cyberspace warfare in the Middle East is a topic that has been rarely addressed and the article provides interesting insights into various aspects and developments in this new type of conflict.
Challenges facing the Arab world in the twenty-first century: an overview
Authors: al-Alkīm Hassan Hamdan
Published: July 2008

This article is a broad and sober assessment of the state of the Arab world. The writer draws a grim picture about prospects for improvements. The Arabs have not benefited from the changes that have swept the world because of the high cost attached to them. Current conditions in the Arab world are the main obstacle facing Arab reformers. In grappling with a civilizational challenge in which Arabs apparently have no choice or role, they suffer from an identity and cultural alienation crisis which impairs their ability to deal with the changes needed.
Democracy and the re-consolidation of authoritarian rule in Egypt
Authors: Abdulbaki Louay
Published: July 2008

Despite the introduction of important liberalization measures, Egypt still suffers from serious democratic deficits. Mubarak’s inconsistent political reforms, especially since the 2005 legislative elections, have raised many questions and revived the discussion on whether Egypt is heading in a democratic direction. This article contributes to this discussion by investigating the political process under Mubarak’s regime and critically analysing the 2005 legislative elections and the 2007 constitutional amendments. It argues that the behaviour of the Egyptian regime since the 2005 elections, particularly with the introduction of the 2007 constitutional amendments, demonstrates its determination to re-consolidate its authoritarian practices.
Shc coordinates signals from intercellular junctions and integrins to regulate flow-induced inflammation
Authors: Liu Yunhao , Sweet Daniel Timothy , Irani-Tehrani Mohamad , Maeda Nobuyo , Tzima Ellie
Published: July 2008

Atherosclerotic plaques develop in regions of the vasculature associated with chronic inflammation due to disturbed flow patterns. Endothelial phenotype modulation by flow requires the integration of numerous mechanotransduction pathways, but how this is achieved is not well understood. We show here that, in response to flow, the adaptor protein Shc is activated and associates with cell–cell and cell–matrix adhesions. Shc activation requires the tyrosine kinases vascular endothelial growth factor receptor 2 and Src. Shc activation and its vascular endothelial cadherin (VE-cadherin) association are matrix independent. In contrast, Shc binding to integrins requires VE-cadherin but occurs only on specific matrices. Silencing Shc results in reduction in both matrix-independent and matrix-dependent signals. Furthermore, Shc regulates flow-induced inflammatory signaling by activating nuclear factor κB–dependent signals that lead to atherogenesis. In vivo, Shc is activated in atherosclerosis-prone regions of arteries, and its activation correlates with areas of atherosclerosis. Our results support a model in which Shc orchestrates signals from cell–cell and cell–matrix adhesions to elicit flow-induced inflammatory signaling.
Calreticulin inhibits commitment to adipocyte differentiation
Authors: Szabo Eva , Qiu Yuanyuan , Baksh Shairaz , Michalak Marek , Opas Michal
Published: July 2008

Calreticulin, an endoplasmic reticulum (ER) resident protein, affects many critical cellular functions, including protein folding and calcium homeostasis. Using embryonic stem cells and 3T3-L1 preadipocytes, we show that calreticulin modulates adipogenesis. We find that calreticulin-deficient cells show increased potency for adipogenesis when compared with wild-type or calreticulin-overexpressing cells. In the highly adipogenic crt−/− cells, the ER lumenal calcium concentration was reduced. Increasing the ER lumenal calcium concentration led to a decrease in adipogenesis. In calreticulin-deficient cells, the calmodulin–Ca2+/calmodulin-dependent protein kinase II (CaMKII) pathway was up-regulated, and inhibition of CaMKII reduced adipogenesis. Calreticulin inhibits adipogenesis via a negative feedback mechanism whereby the expression of calreticulin is initially up-regulated by peroxisome proliferator–activated receptor γ (PPARγ). This abundance of calreticulin subsequently negatively regulates the expression of PPARγ, lipoprotein lipase, CCAAT enhancer–binding protein α, and aP2. Thus, calreticulin appears to function as a Ca2+-dependent molecular switch that regulates commitment to adipocyte differentiation by preventing the expression and transcriptional activation of critical proadipogenic transcription factors.
TWEAK-FN14 signaling induces lysosomal degradation of a cIAP1–TRAF2 complex to sensitize tumor cells to TNFα
Authors: Vince James E. , Chau Diep , Callus Bernard , Wong W. Wei-Lynn , Hawkins Christine J. , Schneider Pascal , McKinlay Mark , Benetatos Christopher A. , Condon Stephen M. , Chunduru Srinivas K. , Yeoh George , Brink Robert , Vaux David L. , Silke John
Published: July 2008

Synthetic inhibitor of apoptosis (IAP) antagonists induce degradation of IAP proteins such as cellular IAP1 (cIAP1), activate nuclear factor κB (NF-κB) signaling, and sensitize cells to tumor necrosis factor α (TNFα). The physiological relevance of these discoveries to cIAP1 function remains undetermined. We show that upon ligand binding, the TNF superfamily receptor FN14 recruits a cIAP1–Tnf receptor-associated factor 2 (TRAF2) complex. Unlike IAP antagonists that cause rapid proteasomal degradation of cIAP1, signaling by FN14 promotes the lysosomal degradation of cIAP1–TRAF2 in a cIAP1-dependent manner. TNF-like weak inducer of apoptosis (TWEAK)/FN14 signaling nevertheless promotes the same noncanonical NF-κB signaling elicited by IAP antagonists and, in sensitive cells, the same autocrine TNFα-induced death occurs. TWEAK-induced loss of the cIAP1–TRAF2 complex sensitizes immortalized and minimally passaged tumor cells to TNFα-induced death, whereas primary cells remain resistant. Conversely, cIAP1–TRAF2 complex overexpression limits FN14 signaling and protects tumor cells from TWEAK-induced TNFα sensitization. Lysosomal degradation of cIAP1–TRAF2 by TWEAK/FN14 therefore critically alters the balance of life/death signals emanating from TNF-R1 in immortalized cells.
Sequential signals toward podosome formation in NIH-src cells
Authors: Oikawa Tsukasa , Itoh Toshiki , Takenawa Tadaomi
Published: July 2008

Podosomes (also termed invadopodia in cancer cells) are actin-rich adhesion structures with matrix degradation activity that develop in various cell types. Despite their significant physiological importance, the molecular mechanism of podosome formation is largely unknown. In this study, we investigated the molecular mechanisms of podosome formation. The expression of various phosphoinositide-binding domains revealed that the podosomes in Src-transformed NIH3T3 (NIH-src) cells are enriched with PtdIns(3,4)P2, suggesting an important role of this phosphoinositide in podosome formation. Live-cell imaging analysis revealed that Src-expression stimulated podosome formation at focal adhesions of NIH3T3 cells after PtdIns(3,4)P2 accumulation. The adaptor protein Tks5/FISH, which is essential for podosome formation, was found to form a complex with Grb2 at adhesion sites in an Src-dependent manner. Further, it was found that N-WASP bound all SH3 domains of Tks5/FISH, which facilitated circular podosome formation. These results indicate that augmentation of the N-WASP–Arp2/3 signal was accomplished on the platform of Tks5/FISH-Grb2 complex at focal adhesions, which is stabilized by PtdIns(3,4)P2.
TWEAKing death
Authors: Ashwell Jonathan D.
Published: July 2008

Smac mimetics (inhibitor of apoptosis [IAP] antagonists) are synthetic reagents that kill susceptible tumor cells by inducing degradation of cellular IAP (cIAP) 1 and cIAP2, nuclear factor κB activation, tumor necrosis factor (TNF) α production, TNF receptor 1 occupancy, and caspase-8 activation. In this issue of The Journal of Cell Biology, Vince et al. (see p. 171) report remarkable similarities in the events leading to tumor cell death triggered by the cytokine TWEAK (TNF-like weak inducer of apoptosis) and IAP antagonists. Although the mechanistic details differ, a common and necessary feature that is also shared by TNF receptor 2 signaling is reduction in the level of cIAP1 and, in some cases, cIAP2 and TNF receptor-associated factor 2. These findings not only extend our appreciation of how cell death pathways are kept in check in tumors, they reinforce the possible utility of induced cIDE (cIAP deficiency) in the selective elimination of neoplastic cells.
Distinct roles of apolipoprotein components within the trypanosome lytic factor complex revealed in a novel transgenic mouse model
Authors: Molina-Portela Maria Pilar , Samanovic Marie , Raper Jayne
Published: July 2008

Humans express a unique subset of high-density lipoproteins (HDLs) called trypanosome lytic factors (TLFs) that kill many Trypanosoma parasite species. The proteins apolipoprotein (apo) A-I, apoL-I, and haptoglobin-related protein, which are involved in TLF structure and function, were expressed through the introduction of transgenes in mice to explore their physiological roles in vivo. Transgenic expression of human apolipoprotein L-I alone conferred trypanolytic activity in vivo. Coexpression of human apolipoprotein A-I and haptoglobin-related protein (Hpr) had an effect on the integration of apolipoprotein L-I into HDL, and both proteins were required to increase the specific activity of TLF, which was measurable in vitro. Unexpectedly, truncated apolipoprotein L-I devoid of the serum resistance gene interacting domain, which was previously shown to kill human infective trypanosomes, was not trypanolytic in transgenic mice despite being coexpressed with human apolipoprotein A-I and Hpr and incorporated into HDLs. We conclude that all three human apolipoproteins act cooperatively to achieve maximal killing capacity and that truncated apolipoprotein L-I does not function in transgenic animals.
Chirita guihaiensis sp. nov. (Gesneriaceae) from Guangxi, China
Authors: Wei Yi‐Gang , Pan Bo , Tang Wen‐Xiu
Published: July 2008

Chirita guihaiensis sp. nov. (Gesneriaceae) is described and illustrated. Chirita guihaiensis resembles C. macrodonta D. Fang & D. H. Qin, but is distinguished by its entire bracts, lack of tri‐nerved sepals, dark purple corolla, and broader corolla tube with purple stripes inside and with the orifice 1.2–2 cm in diameter. However, C. guihaiensis may also be mistaken for C. rotundifolia (Hemsl.) Wood. and C. cordifolia W. T. Wang, but it differs from all these species as in the key presented in the paper.
Family ties: molecular phylogeny of crab spiders (Araneae: Thomisidae)
Authors: Benjamin Suresh P. , Dimitrov Dimitar , Gillespie Rosemary G. , Hormiga Gustavo
Published: July 2008

The first quantitative phylogenetic analysis of three sequenced genes (16S rRNA, cytochromecoxidase subunit I, histone 3) of 25 genera of crab spiders and 11 outgroups supports the monophyly of Thomisidae. Four lineages within Thomisidae are recovered. They are informally named here as theBorboropactusclade,Epidiusclade,Stephanopisclade and theThomisusclade, pending detailed morphology based cladistic work. TheThomisusclade is recovered as a strongly supported monophyletic group with a minimal genetic divergence. Philodromidae previously widely considered a subfamily of Thomisidae do not group within thomisids and is excluded from Thomisidae. However, Aphantochilinae previously generally considered as a separate family falls within theThomisusclade and is included in Thomisidae. The recently proposed new family Borboropactidae is rejected, as it is paraphyletic.

© The Willi Hennig Society 2008.
Parsimony analysis of ecological succession, a powerful tool for interpreting changes in community structure
Authors: Wenzel John W. , Luque Gloria M.
Published: July 2008

We apply cladistic parsimony analysis to data sets from successional ecology, borrowing data from studies of the recovery of different communities, including ants in Spain, ants and birds in Australia, and butterflies in Costa Rica. Resultant parsimony analysis demonstrate increasing diversity, rooted at the poorest site and year, extending to either the various (rich) control sites, or with branches indicating alternative assemblages of species in some study sites. This analysis produces graphical summaries that are useful to evaluate the path of succession (species following one another). We demonstrate that the product of cladistic analysis compares favorably with methods commonly used in ecology, explicitly revealing a hierarchy that may relate closely to a time series, includes rare species, and illustrates how individual species relate to observed patterns. We detail certain operational considerations that influence the performance of the cladistic method, and we discuss the robustness of the method. This technique may be applied to study of the patterns of assemblage of natural or disturbed communities, both when and where each species appears as well as the order of appearance of species to develop a rich community.

© The Willi Hennig Society 2008.