bluuebunny/crossref_metadata_2025 huggingface dataset:
The peopling of America: Craniofacial shape variation on a continental scale and its interpretation from an interdisciplinary view
Authors: González‐José Rolando , Bortolini Maria Cátira , Santos Fabrício R. , Bonatto Sandro L.
Published: May 2008

Twenty‐two years ago, Greenberg, Turner and Zegura (Curr. Anthropol. 27,477–495, 1986) suggested a multidisciplinary model for the human settlement of the New World. Since their synthesis, several studies based mainly on partial evidence such as skull morphology and molecular genetics have presented competing, apparently mutually exclusive, settlement hypotheses. These contradictory views are represented by the genetic‐based Single Wave or Out of Beringia models and the cranial morphology‐based Two Components/Stocks model. Here, we present a geometric morphometric analysis of 576 late Pleistocene/early Holocene and modern skulls suggesting that the classical Paleoamerican and Mongoloid craniofacial patterns should be viewed as extremes of a continuous morphological variation. Our results also suggest that recent contact among Asian and American circumarctic populations took place during the Holocene. These results along with data from other fields are synthesized in a model for the settlement of the New World that considers, in an integrative and parsimonious way, evidence coming from genetics and physical anthropology. This model takes into account a founder population occupying Beringia during the last glaciation characterized by high craniofacial diversity, founder mtDNA and Y‐chromosome lineages and some private autosomal alleles. After a Beringian population expansion, which could have occurred concomitant with their entry into America, more recent circumarctic gene flow would have enabled the dispersion of northeast Asian‐derived characters and some particular genetic lineages from East Asia to America and vice versa. Am J Phys Anthropol, 2008. © 2008 Wiley‐Liss, Inc.
Cognition 6 years after surgical or medical therapy for coronary artery disease
Authors: Selnes Ola A. , Grega Maura A. , Bailey Maryanne M. , Pham Luu D. , Zeger Scott L. , Baumgartner William A. , McKhann Guy M.
Published: May 2008

Objective

The choice of coronary artery bypass grafting (CABG) as an intervention for coronary artery disease has been clouded by concerns about postoperative cognitive decline. Long‐term cognitive decline after CABG has been reported, but without appropriate control subjects, it is not known whether this decline is specific to CABG or related to other factors such as cerebrovascular disease.

Methods

This prospective, observational study of patients with diagnosed coronary artery disease included 152 CABG and 92 nonsurgical cardiac comparison patients from one institution. The main outcome measure was within‐patient change in cognitive performance for eight cognitive domains from baseline to 12‐ and 72‐month follow‐up.

Results

Mild late cognitive decline was observed for both study groups, but despite greater than 80% power to detect a 0.2 standard deviation difference, there were no statistically significant differences between the surgical and nonsurgical patients in the degree of change from 12 to 72 months for any cognitive domain. There was also no difference between groups in the degree of change from baseline to 72 months or in the number of patients with a Mini‐Mental State Examination score in the clinically impaired range at 72 months.

Interpretation

Late cognitive decline does occur in patients who have undergone CABG surgery, but the degree of this decline does not differ from that observed in patients of similar age with coronary artery disease who have not undergone CABG. Therefore, late cognitive decline after CABG is not specific to the use of cardiopulmonary bypass. Ann Neurol 2008;63:581–590
Repairing the human brain after stroke. II. Restorative therapies
Authors: Cramer Steven C.
Published: May 2008

Spontaneous behavioral recovery is usually limited after stroke, making stroke a leading source of disability. A number of therapies in development aim to improve patient outcomes not by acutely salvaging threatened tissue, but instead by promoting repair and restoration of function in the subacute or chronic phase after stroke. Examples include small molecules, growth factors, cell‐based therapies, electromagnetic stimulation, device‐based strategies, and task‐oriented and repetitive training‐based interventions. Stage of development across therapies varies widely, from preclinical to late‐phase clinical trials. The optimal methods to prescribe such therapies require further studies, for example, to best identify appropriate patients or to guide features of dosing. Likely, anatomic, functional, and behavioral measures of brain state, as well as measures of injury, will each be useful in this regard. Considerations for clinical trials of restorative therapies are provided, emphasizing both similarities and points of divergence with acute stroke clinical trial design. Ann Neurol 2008;63:549–560
PPgMA/APTS compound coupling compatabilizer in PP/clay hybrid nanocomposite
Authors: Liaw Wen‐Chang , Huang Po‐Chen , Chen Chee‐Shan , Lo Chi‐Lang , Chang Ju‐Liang
Published: May 2008

A compound coupling compatibilizer employing coupled use of γ‐(aminopropyl) triethoxy silane (APTS) and maleic anhydride‐graft‐polypropylene (PPgMA) was synthesized for the preparation of polypropylene (PP)/clay hybrid nanocomposites. The designed PPgMA/APTS compound coupling compatabilizer, through condensation of the amino groups of APTS with the anhydride groups of MA moieties in PPgMA, is capable of forming chemical bonding with the organo clay (org‐clay) while maintaining compatibility with the organic PP compartment. Various PPgMA to APTS ratios of these compound coupling compatibilizers were first reacted with clay to form PPgMA/clay masterbatches. The obtained masterbatches were then compounded with PP to produce PP/clay hybrid nanocomposites possessing different characteristics. The composition effects were studied. For org‐clay content of 5 wt %, intercalated‐exfoliated structure of the nanocomposite could be maintained for better reinforcement. Td of 484°C was achieved, indicating significant improvement over neat PP (Td was 386°C) in thermal property. The ultimate tensile strength (30% higher than control) and Young's modulus (57% higher than control) measurements also justified the application of the PPgMA/APTS compound coupling compatibilizer in the incorporation of org‐clay in PP matrix. The use of the PPgMA/APTS compound coupling compatibilizer can provide design flexibility in manufacturing PP/clay hybrid nanocomposites. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Diet factors responsible for the change of the glucose oxidase activity in labial salivary glands of Helicoverpa armigera
Authors: Hu Yong‐Hong , Leung David W.M. , Kang Le , Wang Chen‐Zhu
Published: May 2008

We investigated the change of the glucose oxidase (GOX) activity in labial salivary glands of Helicoverpa armigera larvae fed with the artificial diet or host plant tobacco and the major factors responsible for such a change. Throughout larval development, the labial salivary GOX activities in caterpillars reared on the artificial diet were remarkably higher than those fed with the plant. After fifth‐instar plant‐fed caterpillars were transferred to the artificial diet, their labial salivary GOX activity increased quickly, which was closely correlated with the time spent feeding on the artificial diet. The total sugar content of the artificial diet was 68 times higher than that of the tobacco leaves. We hypothesized that sugars and secondary metabolites are the possible causes of induction of GOX activity. When fifth‐instar caterpillars were fed with tobacco leaves coated with glucose or sucrose, their labial salivary GOX activity was significantly higher than those fed with leaves without sugar coating. Following native PAGE, 1 single band of the labial salivary GOX was observed in all the caterpillars fed with different diets, implying that only the activity of the isoenzyme was changed in response to different diets. Furthermore, the labial salivary GOX activity was determined after caterpillars were fed with artificial diets containing chlorogenic acid, rutin, and quercetin. The results showed that all these phenolic compounds had no effect on the GOX activity. We conclude that sugar in diets was a major factor influencing the labial salivary GOX activity of the larvae. Arch. Insect Biochem. Physiol. 2008. © 2008 Wiley‐Liss, Inc.
Molecular cloning and expression profiles of the acyl‐CoA‐binding protein gene from the cotton bollworm Helicoverpa armigera
Authors: Wang Jia‐Lin , Wang Jin‐Xing , Zhao Xiao‐Fan
Published: May 2008

Acyl‐CoA‐binding protein (ACBP), also known as the diazepam‐binding inhibitor (DBI), has been identified in diverse species and is evolutionarily conserved in plants and animals. In a recent study, an ACBP cDNA (HaACBP) encoding 85 amino acids was isolated from the cotton bollworm Helicoverpa armigera. The isolated protein is highly homologous to the ACBP present in the Bombyx mori midgut, where it is highly expressed. Northern and Western blot analyses revealed that HaACBP is expressed predominantly in the midgut. Moreover, Northern blotting revealed that HaACBP was probably stimulated by a high juvenile hormone titer at ecdysis and increased along with feeding at 12 h post‐ecdysis. Immunohistochemistry of the midgut revealed that HaACBP is localized in columnar cells. Data from the Northern blotting and immunohistochemistry suggested that HaACBP was expressed during the larval period and is probably responsible for nutrition absorption. However, Western blot analysis of the midgut at different developmental stages indicated that HaACBP was upregulated during larval molting and metamorphosis, which suggested that HaACBP expression was posttranscriptionally regulated. Arch. Insect Biochem. Physiol. 68:79–88, 2008. © 2008 Wiley‐Liss, Inc.
Starvation influences allatotropin gene expression and juvenile hormone titer in the female adult oriental armyworm, Mythimna separata
Authors: Zhang Lei , Luo Lizhi , Jiang Xingfu
Published: May 2008

The first day of adult life is the sensitive stage for shifting migrants into the resident morphs of the oriental armyworm (OAW), Mythimna separata (Walker). The juvenile hormone (JH) titer, expression of the allatotropin (AT) gene, and their relationship were investigated in adult female migrants starved in the sensitive stage, to understand the underlying mechanism of changing migrants into resident OAWs. Haemolymph JH titers of the starved female adults were mostly elevated earlier than in controls, although not all differences were statistically significant. JH I titers in the starved moths were significantly higher than those in the controls on 1, 2, and 5 days after treatment (DAT), respectively. JH II titers in the starved moths were significantly higher than the controls through the period tested except on 5 DAT. JH II is the most likely regulator in changing migrants into resident morphs. The relative quantities of AT expression in the starved moths were higher through the period tested except on 5 DAT. AT expression and JH titers appear to be positively correlated, especially for those in earlier days of the adult life. We infer that AT is the important regulator of JH levels. A model for the shifting of migrants into resident morphs in the OAW is proposed. Arch. Insect Biochem. Physiol. 68:63–70, 2008. © 2008 Wiley‐Liss, Inc.
An empirical investigation of the g‐index for 26 physicists in comparison with the h‐index, the A‐index, and the R‐index
Authors: Schreiber Michael
Published: May 2008

J.E. Hirsch (2005) introduced the h‐index to quantify an individual's scientific research output by the largest number h of a scientist's papers that received at least h citations. To take into account the highly skewed frequency distribution of citations, L. Egghe (2006a) proposed the g‐index as an improvement of the h‐index. I have worked out 26 practical cases of physicists from the Institute of Physics at Chemnitz University of Technology, and compare the h and g values in this study. It is demonstrated that the g‐index discriminates better between different citation patterns. This also can be achieved by evaluating B.H. Jin's (2006) A‐index, which reflects the average number of citations in the h‐core, and interpreting it in conjunction with the h‐index. h and A can be combined into the R‐index to measure the h‐core's citation intensity. I also have determined the A and R values for the 26 datasets. For a better comparison, I utilize interpolated indices. The correlations between the various indices as well as with the total number of papers and the highest citation counts are discussed. The largest Pearson correlation coefficient is found between g and R. Although the correlation between g and h is relatively strong, the arrangement of the datasets is significantly different depending on whether they are put into order according to the values of either h or g.
A framework for describing correlated excitation of solar p‐modes
Authors: Chaplin W. J. , Elsworth Y. , Toutain T.
Published: May 2008

In a previous paper we suggested that, for a given p mode, the excitation function is the same as the component of the solar background noise that has an identical surface spherical harmonic projection (over the corresponding range of temporal frequency). An important consequence of this surmise is that the excitation of overtones of a given angular degree and azimuthal order will be correlated in time. In this note, we introduce the basic principles and a mathematical description of correlated mode excitation. We use simple, illustrative examples, involving two modes. Our treatment suggests that in the real observations, any signatures of the correlation would not appear as a correlation of the output amplitudes of overtones, but rather as subtle modifications to the power spectral density at frequencies between the central frequencies of the overtones. These modifications give a contribution to the observed peak asymmetries. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A modified peak‐bagging technique for fitting low‐𝓁 solar p‐modes
Authors: Fletcher S.T. , Chaplin W.J. , Elsworth Y. , New R.
Published: May 2008

We introduce a modified version of a standard power spectrum ‘peak‐bagging’ technique which is designed to gain some of the advantages that fitting the entire low‐degree p‐mode power spectrum simultaneously would bring, but without the problems involved in fitting a model incorporating many hundreds of parameters. Employing Monte‐Carlo simulations we show that by using this modified fitting code it is possible to determine the true background level in the vicinity of the p‐mode peaks. In addition to this we show how small biases in other mode parameters, which are related to inaccurate estimates of the true background, are also consequently removed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
YAOPBM – yet another peak bagging method
Authors: Korzennik S. G.
Published: May 2008

I present and discuss the fitting methodology I developed for very‐long time series (2088‐day‐long). This new method was first used to fit low degree modes, 𝓁 ≤ 25. That time series was also sub‐divided in somewhat shorter segments (728‐daylong) and also fitted for these low degrees, in order to measure changes with the solar activity level.

I have recently extended the fitting in several “directions”: 1) to substantially higher degrees (𝓁 ≤ 125), 2) to shorter time series (364‐ and 182‐day‐long), and, 3) to additional 728‐day‐long segments, covering now some 10 years of observations. I present and discuss issues related to this expansion, namely problems at low frequencies affecting the f and p1 modes, and the inadequacy of the leakage matrix at higher degrees. I also present some of the characteristics of the observed temporal changes in the resulting frequencies. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Update on g‐mode research
Authors: García R.A. , Jiménez A. , Mathur S. , Ballot J. , Eff‐Darwich A. , Jiménez‐Reyes S. J. , Pallé P. L. , Provost J. , Turck‐Chièze S.
Published: May 2008

Since the beginning of this century we have attended a blooming of the gravity‐mode research thanks to the unprecedented quality of the data available, either from space with SoHO, or from the ground‐based networks as BiSON or GONG. From the first upper limit of the gravity‐mode amplitudes fixed at 10 mm/s at 200 μ Hz given by Appourchaux et al. (2000), on one hand, a peak was supposed to be a component of the 𝓁 = 1, n = 1 mixed mode (García et al. 2001a, 2001b; Gabriel et al. 2002) and, on the other hand, a couple of patterns – multiplets – were attributed to gravity modes (Turck‐Chièze et al. 2004; Mathur et al. 2007). One of these patterns, found around 220 μ Hz, could be labeled as the 𝓁 = 2, n = –3 g mode, which is expected to be the one with the highest surface amplitude (Cox & Guzik 2004). Finally, in 2007, García et al. were able to measure the fingertips of the dipole gravity modes looking for their asymptotic properties. In the present paper we present an update of the recent developments on this subject with special attention to the 220 μ Hz region, the dipole asymptotic properties and the impact of the incoming g‐mode observations on the knowledge of the solar structure and rotation profile. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preliminary results on the determination of the theoretical nonadiabatic observable phase lag (ψT) using VIRGO color photometry
Authors: Simoniello R. , Garrido R. , Jiménez A.
Published: May 2008

The helioseismic instruments aboard the SOHO satellite make it possible to measure solar oscillations as variations of the irradiance (VIRGO) or as variations of the photospheric velocity (GOLF). Theoretically, phase differences between different photometric bands are expected to be around 0 degrees over the p‐mode frequency range. By using VIRGO (red) and VIRGO (blue) data, we find a mean phase shift of 8.05 ± 1.81°, whereas by using VIRGO (green) and VIRGO (blue) data, we got a mean value of –1.04 ± 0.19°. Hence, when the analysis includes the VIRGO infrared range, the Sun's atmosphere does not follow an exact adiabatic behavior. In this study, we use the phase shifts obtained by VIRGO (green) and VIRGO (blue) to determine the non‐adiabatic parameter phase lag (ψT) as a function of frequency. To this aim, we applied the non radial linearized formula put in the complex form by Garrido: we found a mean value of ψT = 179.95°. The lowest value being ψT = 179.90°, the departure from theoretical predictions is less then a tenth of a degree over the entire p mode frequency range. We can state that the solar atmosphere has a behavior close to the adiabatic case, when the phase shifts and amplitude ratios are computed using VIRGO (green) and VIRGO (blue) data. Nevertheless this small deviation is significant. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The visibility of low‐frequency solar acoustic modes
Authors: Broomhall A. M. , Chaplin W. J. , Elsworth Y. , Fletcher S. T.
Published: May 2008

We make predictions of the detectability of low‐frequency p modes. Estimates of the powers and damping times of these low‐frequency modes are found by extrapolating the observed powers and widths of higher‐frequency modes with large observed signal‐to‐noise ratios. The extrapolations predict that the low‐frequency modes will have small signal‐to‐noise ratios and narrow widths in a frequency‐power spectrum. Monte Carlo simulations were then performed where timeseries containing mode signals and normally distributed Gaussian noise were produced. The mode signals were simulated to have the powers and damping times predicted by the extrapolations. Various statistical tests were then performed on the frequency‐amplitude spectra formed from these timeseries to investigate the fraction of spectra in which the modes could be detected. The results of these simulations were then compared to the number of p‐modes candidates observed in real Sun‐as‐a‐star data at low frequencies. The fraction of simulated spectra in which modes were detected decreases rapidly as the frequency of modes decreases and so the fraction of simulations in which the low‐frequency modes were detected was very small. However, increasing the signal‐to‐noise (S/N) ratio of the low‐frequency modes by a factor of 2 above the extrapolated values led to significantly more detections. Therefore efforts should continue to further improve the quality of solar data that is currently available. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Laboratory performances of the solar multichannel resonant scattering spectrometer prototype of the GOLF‐New Generation instrument
Authors: Turck‐Chièze S. , Carton P.H. , Mathur S. , Barrière J.‐C. , Daniel‐Thomas P. , Lahonde‐Hamdoun C. , Loiseau D. , Nunio F. , Piret Y. , Robillot J.M.
Published: May 2008

This article quickly summarizes the performances and results of the GOLF/SoHO resonant spectrometer, thus justifying to go a step further. We then recall the characteristics of the multichannel resonant GOLF‐NG spectrometer and present the first successful performances of the laboratory tests on the prototype and also the limitations of this first technological instrument. Scientific questions and an observation strategy are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The effect of turbulent mixing on the g‐mode spectrum of MS stars
Authors: Montalbán J. , Miglio A. , Eggenberger P. , Noels A.
Published: May 2008

Understanding transport processes inside stars is one of the main goals of asteroseismology. Chemical turbulent mixing can affect the internal distribution of μ near the energy generating core, having an effect on the evolutionary tracks similar to that of overshooting. This mixing leads to a smoother chemical composition profile near the edge of the convective core, which is reflected in the behavior of the buoyancy frequency and, therefore, in the frequencies of gravity modes. We describe the effects of convective overshooting and turbulent mixing on the frequencies of gravity modes in B‐type main sequence stars. In particular, the cases of p‐g mixed modes in β Cep stars and high‐order modes in SPBs are considered. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A procedure for modelling asymptotic g‐mode pulsators: The case of γ Doradus stars
Authors: Moya A. , Suárez J.C. , Martín‐Ruiz S. , Amado P.J. , Rodríguez‐López C. , Grigahcène A. , Dupret M.A. , Rodríguez E. , Garrido R.
Published: May 2008

Mode identification is one of the first and main problems we encounter in trying to develop the complete potential of asteroseismology. In the particular case of g‐mode pulsators, this is still an unsolved problem, from both the observational and theoretical points of view. Nevertheless, in recent years, some observational and theoretical efforts have been made to find a solution. In this work we use the latest theoretical and computational tools to understand asymptotic g‐mode pulsators: 1) the Frequency Ratio Method, and 2) Time Dependent Convection. With these tools, a self‐consistent procedure for mode identification and modelling of these g‐mode pulsators can be constructed. This procedure is illustrated using observational information available for the γ Doradus star 9Aurigae. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of the stellar inclination angle upon theoretical errors of l = 1 p‐mode parameters
Authors: Ballot J. , Appourchaux T. , Toutain T.
Published: May 2008

The asteroseismic observations provided by current and future missions like CoRoT or Kepler will have a quality closer to those obtained for the Sun. In this context, tools and methods developed for helioseismology can be applied to other stars. In this paper, we focus on solar‐like oscillations of stars with an unknown rotation axis inclination and study, by means of maximum‐likelihood estimation, the errors on the determination of l = 1 p‐mode parameters. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Decisional comprehensiveness and firm performance: towards a more complete understanding
Authors: Miller C. Chet
Published: May 2008

Organizational prosperity and even survival can be threatened unless strategic decisions are made through an effective process. But what does an effective decision‐making process look like? Analysts and executives have struggled over the years to answer this question. Recently, however, empirical research has produced a consistent answer for one of the most fundamental aspects of strategic decision‐making: comprehensiveness. This recent work suggests that higher levels of comprehensiveness are positive for firms facing turbulent conditions but are irrelevant for firms facing stable conditions. While this consistency would seem to be positive, it presents a puzzle: Why are comprehensiveness and performance unrelated in stable environments? In such environments, problems generally believed to plague comprehensive decision‐making are less severe. The theory building and empirical results of the present research suggest a solution to the puzzle: comprehensiveness and performance exhibit a relationship more complex than previous studies have been designed to detect. Copyright © 2008 John Wiley & Sons, Ltd.
Herding by attribution of privileged information
Authors: Quiamzade Alain , L'Huillier Jean‐Paul
Published: May 2008

We study a situation where agents take extreme actions and how these actions are imitated by others. First, Experiment 1 showed that an expert first mover had an advantage in obtaining herding by others on his investment decision, when compared to a non‐expert first mover. Experiment 2 showed that this advantage only appeared when the first mover's investment was out‐of‐the‐ordinary (in fact, highly aberrant). We obtained the same level of herding in Experiment 3 when the first mover had privileged information, instead of being an expert. Second, Experiment 4 showed that when people observed the same out‐of‐the‐ordinary investment and did not know whether the first mover had privileged information or not, they herded on him as if he had privileged information. In fact, our data revealed that participants thought that the unknown first mover had privileged information. Furthermore, herding was statistically indistinguishable from the condition where observers knew unambiguously that the first mover had privileged information. Copyright © 2008 John Wiley & Sons, Ltd.
Ultralong Carbon–Carbon Bonds in Dispirobis(10‐methylacridan) Derivatives with an Acenaphthene, Pyracene, or Dihydropyracylene Skeleton
Authors: Kawai Hidetoshi , Takeda Takashi , Fujiwara Kenshu , Wakeshima Makoto , Hinatsu Yukio , Suzuki Takanori
Published: May 2008

Acenapthalene, pyracene, and dihydropyracylene attached to two units of spiroacridan are a novel class of hexaphenylethane (HPE) derivatives that have an ultralong CC bond (1.77–1.70 Å). These sterically challenged molecules were cleanly prepared by CC bond formation through two‐electron reduction from the less‐hindered dications. These ultralong bonds were realized based on several molecular‐design concepts including enhanced “front strain” through “multiclamping” by means of fusing or bridging aryl groups in the HPE molecule. The lengths of these ultralong bonds and their relation to the conformation (torsional angle) were also validated by means of theoretical calculations. Bond‐fission experiments revealed that the bonds are more easily cleaved than standard covalent bonds to produce the corresponding dication upon oxidation with an increase in the length of the CC bond.
Hormone‐dependent expression of fasciclin II during ganglionic migration and fusion in the ventral nerve cord of the moth Manduca sexta
Authors: Himes Katherine E. , Klukas Kathleen A. , Fahrbach Susan E. , Mesce Karen A.
Published: May 2008

The ventral nerve cord of holometabolous insects is reorganized during metamorphosis. A prominent feature of this reorganization is the migration of subsets of thoracic and abdominal larval ganglia to form fused compound ganglia. Studies in the hawkmoth Manduca sexta revealed that pulses of the steroid hormone 20‐hydroxyecdysone (20E) regulate ganglionic fusion, but little is known about the cellular mechanisms that make migration and fusion possible. To test the hypothesis that modulation of cell adhesion molecules is an essential component of ventral nerve cord reorganization, we used antibodies selective for either the transmembrane isoform of the cell adhesion receptor fasciclin II (TM‐MFas II) or the glycosyl phosphatidylinositol‐linked isoform (GPI‐MFas II) to study cell adhesion during ganglionic migration and fusion. Our observations show that expression of TM‐MFas II is regulated temporally and spatially. GPI‐MFas II was expressed on the surface of the segmental ganglia and the transverse nerve, but no evidence was obtained for regulation of GPI‐MFas II expression during metamorphosis of the ventral nerve cord. Manipulation of 20E titers revealed that TM‐MFas II expression on neurons in migrating ganglia is regulated by hormonal events previously shown to choreograph ganglionic migration and fusion. Injections of actinomycin D (an RNA synthesis inhibitor) or cycloheximide (a protein synthesis inhibitor) blocked ganglionic movement and the concomitant increase in TM‐MFas II, suggesting that 20E regulates transcription of TM‐MFas II. The few neurons that showed TM‐MFas II immunoreactivity independent of endocrine milieu were immunoreactive to an antiserum specific for eclosion hormone (EH), a neuropeptide regulator of molting. J. Comp. Neurol. 509:319–339, 2008. © 2008 Wiley‐Liss, Inc.
Tauopathy with paired helical filaments in an aged chimpanzee
Authors: Rosen Rebecca F. , Farberg Aaron S. , Gearing Marla , Dooyema Jeromy , M. Long Patrick , Anderson Daniel C. , Davis‐Turak Jeremy , Coppola Giovanni , Geschwind Daniel H. , Paré Jean‐Francois , Duong Timothy Q. , Hopkins William D. , Preuss Todd M. , Walker Lary C.
Published: May 2008

An enigmatic feature of age‐related neurodegenerative diseases is that they seldom, if ever, are fully manifested in nonhuman species under natural conditions. The neurodegenerative tauopathies are typified by the intracellular aggregation of hyperphosphorylated microtubule‐associated protein tau (MAPT) and the dysfunction and death of affected neurons. We document the first case of tauopathy with paired helical filaments in an aged chimpanzee (Pan troglodytes). Pathologic forms of tau in neuronal somata, neuropil threads, and plaque‐like clusters of neurites were histologically identified throughout the neocortex and, to a lesser degree, in allocortical and subcortical structures. Ultrastructurally, the neurofibrillary tangles consisted of tau‐immunoreactive paired helical filaments with a diameter and helical periodicity indistinguishable from those seen in Alzheimer's disease. A moderate degree of Aβ deposition was present in the cerebral vasculature and, less frequently, in senile plaques. Sequencing of the exons and flanking intronic regions in the genomic MAPT locus disclosed no mutations that are associated with the known human hereditary tauopathies, nor any polymorphisms of obvious functional significance. Although the lesion profile in this chimpanzee differed somewhat from that in Alzheimer's disease, the copresence of paired helical filaments and Aβ‐amyloidosis indicates that the molecular mechanisms for the pathogenesis of the two canonical Alzheimer lesions—neurofibrillary tangles and senile plaques—are present in aged chimpanzees. J. Comp. Neurol. 509:259–270, 2008. © 2008 Wiley‐Liss, Inc.
Cardiorespiratory dynamics during transitions between mechanical and spontaneous ventilation in intensive care
Authors: Burykin Anton , Buchman Timothy G.
Published: May 2008

Life support devices (e.g., heart pacemakers, ventilators, dialysis machines) are commonly thought to affect mainly their target organ system. This preliminary study attempts to determine the extent to which mechanical support of one organ system (lungs by mechanical ventilator) affects functions of other systems (heart and blood vessels). We studied changes in cardiorespiratory interactions and in dynamics of cardiovascular system during scheduled transitions (spontaneous breathing trials, SBT) between mechanical and spontaneous ventilation in critically ill patients. This initial study population consisted of 13 patients admitted to a surgical intensive care unit (ICU) following surgery, trauma, or complications who were judged candidates for liberation from the ventilator. We collected continuous respiratory, cardiac (ECG), and perfusion (blood pressure and pulse oximetry) signals of mechanically ventilated patients before, during, and after SBT. The data were analyzed using spectral analysis, phase dynamics, and entropy measures. We found that the mechanical ventilation not only drives lung dynamics but also affects the dynamics of cardiac and vascular systems. Spontaneous cardiovascular rhythms are entrained by the mechanical ventilator and are drawn into synchrony. Sudden interruption of mechanical ventilation typically leads to rapid desynchronization. This synchronization is restored upon reinstitution of mechanical ventilation. The initial data suggest that therapies intended to support one organ system may propagate unanticipated effects to other organ systems. Moreover, sustained therapies may disturb mechanisms that promote natural synchronization and variability and thereby adversely affect recovery of normal organ system interactions. We suggest that new measures and displays of synchronization not only could provide insight into the organ–organ coupling but also could yield information to optimize the function of devices used to support the critically ill patient. © 2008 Wiley Periodicals, Inc. Complexity, 2008
Pathogenesis of osteoarthritis: Chondrocyte replicative senescence or apoptosis?
Authors: Takács‐Buia Luminita , Iordachel Catalin , Efimov Nicolae , Caloianu Maria , Montreuil Jean , Bratosin Daniela
Published: May 2008

Background:

The aim of this study was to investigate by flow cytometry cellular viability and apoptosis of human chondrocytes isolated from osteoarthritic cartilage and to correlate replicative senescence with apoptosis of these cells.

Methods:

To understand the mechanisms underlying the process of cell death in cartilage destruction, we investigated by flow cytometry cellular viability (Cell viability calcein‐AM assay) and apoptosis (Light scattering properties of chondrocytes, study of chondrocyte death using Annexin‐V‐FITC and propidium iodide double‐labeling, caspase‐3 activity determination) of human chondrocytes isolated from osteoarthritic and nonosteoarthritic cartilage. Senescent cells were characterized using the senescence‐associated‐β‐galactosidase marker (SA‐β‐Gal marker) by staining with chromogenic substrate (X‐Gal) to produce blue coloration of SA‐β‐Gal‐positive cells and microscopy analysis.

Results:

The results we obtained show that between 25 and 40% of chondrocytes were in apoptosis and all of them were SA‐β‐Gal‐positive.

Conclusions:

These results demonstrate that the death of osteoarthritic chondrocytes is an apoptotic phenomenon which is preceded by an accelerated mechanism of replicative senescence. © 2008 Clinical Cytometry Society
The New Energetic Compounds 1,5‐Diaminotetrazolium and 5‐Amino‐1‐methyltetrazolium Dinitramide – Synthesis, Characterization and Testing
Authors: Klapötke Thomas M. , Stierstorfer Jörg
Published: May 2008

The new energetic compounds 1,5‐diamino‐1H‐tetrazol‐4‐ium dinitramide (1) and 5‐amino‐1‐methyl‐1H‐tetrazol‐4‐ium dinitramide (2) were synthesized by the reaction of potassium dinitramide with 1,5‐diamino‐1H‐tetrazolium perchlorate and 5‐amino‐1‐methyl‐1H‐tetrazolium perchlorate, respectively. Both compounds were fully characterized by single‐crystal X‐ray diffraction, IR and Raman spectroscopy, multinuclear (1H, 13C, 14N, 15N) NMR spectroscopy, differential scanning calorimetry, and mass spectrometry. In addition, their sensitivities towards impact, friction, and electrical discharge were investigated. The heats of formation were calculated (CBS‐4M) in an extensive computational study. The detonation parameters of 1 and 2 were calculated by using the EXPLO5 software. The calculations yielded auspicious values for potential application as highly explosive compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Chromosome aberrations and telomere length modulation in bone marrow and spleen cells of melphalan‐treated p53+/− mice
Authors: Sgura Antonella , De Amicis Andrea , Stronati Laura , Cinelli Serena , Pacchierotti Francesca , Tanzarella Caterina
Published: May 2008

The p53 gene regulates cell cycle and apoptotic pathways after induction of DNA damage. Telomeres, capping chromosome ends, are involved in maintaining chromosome stability; alterations of their length have been related to increased levels of chromosomal aberrations. To study a possible interaction between chromosome aberrations, telomere dysfunction, and p53, we investigated via painting analysis the induction and persistence of chromosome aberrations in bone marrow and spleen cells of p53+/− (and wild type) mice exposed for 4, 13, or 26 weeks to 2 mg/kg melphalan (MLP), a chemotherapeutic agent with carcinogenic potential. In addition, telomere length was evaluated in bone marrow cells by quantitative fluorescence in situ hybridization (Q‐FISH). Chromosome aberrations were significantly increased in both tissues after MLP treatment. The p53 genotype did not influence the response of spleen cells, whereas a slight but significant increase of the aberration frequency was measured in the bone marrow of p53+/− mice exposed to MLP for 13 weeks with respect to the level detected in the matched wild‐type group. The main finding of our still preliminary results on telomere length modulation was again a difference between the two genotypes. In bone marrow cells of wild‐type mice, MLP treatment was associated with telomere shortening, while in p53+/− mice telomere elongation was the prevalent response to MLP exposure. In agreement with previous literature data, our in vivo study suggests that even the lack of a single functional copy of the p53 gene might have an impact on the quantity and quality of chromosome alterations induced in cycling cells by a clastogenic exposure. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Brief novelty exposure facilitates dentate gyrus LTP in aged rats
Authors: Sierra‐Mercado Demetrio , Dieguez Dario , Barea‐Rodriguez Edwin J.
Published: May 2008

Aging is associated with a decreased capacity for dentate gyrus (DG) granule cell depolarization as well as reduced perforant path activation. Although it is well established that the maintenance of DG long‐term potentiation (LTP) over days is impaired in aged, as compared to young animals, the threshold for inducing this LTP has never been investigated in aged, awake animals. In addition, although exposure to novelty prior to θ‐burst stimulation (TBS) increases both the induction and longevity of DG LTP in adult rats, the effects of exposure to novelty on LTP in aged rats have never been investigated. Here, we report that although TBS delivered in the home cage induces robust and long‐lasting DG LTP in young rats, TBS fails to induce DG LTP in aged rats. Interestingly, delivery of TBS to aged rats exploring novel environments induces robust and long‐lasting LTP, with the induction, but not the longevity, of this LTP being similar in magnitude to that observed in young rats delivered TBS in the home cage. These results indicate that although TBS‐induced DG LTP is impaired in aged, as compared to young rats, TBS during exploration of novel environments is sufficient to rescue age‐related deficits in DG LTP. We discuss these observations in the context of previous findings suggesting that the facilitation of LTP by exposure to novel environments results as a consequence of reduced network inhibition in the DG and we suggest that, in spite of age‐related changes in the DG, this capacity persists in aged rats and represents a nondietary and nonpharmacological way to facilitate DG LTP during aging. © 2008 Wiley‐Liss, Inc.
Effects of aging on agmatine levels in memory‐associated brain structures
Authors: Liu Ping , Chary Sree , Devaraj Renuka , Jing Yu , Darlington Cynthia L. , Smith Paul F. , Tucker Ian G. , Zhang Hu
Published: May 2008

Agmatine is a metabolite of L‐arginine by arginine decarboxylase. Recent evidence suggests that it exists in mammalian brain and is a novel neurotransmitter. The present study measured agmatine levels in several memory‐associated brain structures in aged (24‐month‐old), middle‐aged (12‐month‐old), and young (4‐month‐old) male Sprague Dawley rats using liquid chromatography/mass spectrometry. Agmatine levels were significantly decreased in the CA1, but increased in the CA2/3 and dentate gyrus, subregions of the hippocampus in aged and middle‐aged rats relative to the young adults. In the prefrontal cortex, a dramatic decrease in agmatine level was found in aged rats as compared with middle‐aged and young rats. There were significantly increased levels of agmatine in the entorhinal and perirhinal cortices in aged relative to middle‐aged and young rats. In the postrhinal and temporal cortices, agmatine levels were significantly increased in aged and middle‐aged rats as compared with young adults. The present findings, for the first time, demonstrate age‐related changes in agmatine levels in memory‐associated brain structures and raise a novel issue of the potential involvement of agmatine in the aging process. © 2008 Wiley‐Liss, Inc.
Distinct, but compensatory roles of PAK1 and PAK3 in spine morphogenesis
Authors: Boda Bernadett , Jourdain Lorena , Muller Dominique
Published: May 2008

PAK1 and PAK3 belong to a family of protein kinases that are effectors of small Rho GTPases. In humans, mutations of PAK3 have been associated with mental retardation and result in in vitro studies in defects of spine morphogenesis. The functional specificities of PAK1 and PAK3 remain, however, unclear. Here, we investigated using loss and gain of function experiments how PAK1 and PAK3 affect spine morphology in hippocampal slice cultures. We find that while knockdown of PAK3 is associated with an increase in thin, elongated, immature‐type spines, downregulation of PAK1 does not alter spine morphology. Conversely, expression of a constitutively active form of PAK3 remains without effect, while expression of constitutively active PAK1 results in the formation of spines with smaller head diameters. Interestingly, expression of constitutively active PAK1 can rescue the long spine phenotype induced by suppression of PAK3. We conclude that while PAK1 and PAK3 share distinct roles in the regulation of spine morphogenesis, their activity may overlap allowing the compensation of the PAK3 deficit by PAK1. This result opens interesting perspectives in the context of reversing the spine defects associated with PAK3 mutations. © 2008 Wiley‐Liss, Inc.
Is α‐lipoic acid a scavenger of reactive oxygen species in vivo? Evidence for its initiation of stress signaling pathways that promote endogenous antioxidant capacity
Authors: Petersen Shay Kate , Moreau Régis F. , Smith Eric J. , Hagen Tory M.
Published: May 2008

The chemical reduction and oxidation (redox) properties of α‐lipoic acid (LA) suggest that it may have potent antioxidant potential. A significant number of studies now show that LA and its reduced form, dihydrolipoic acid (DHLA), directly scavenge reactive oxygen species (ROS) and reactive nitrogen species (RNS) species and protect cells against a host of insults where oxidative stress is part of the underlying etiology. However, owing to its limited and transient accumulation in tissues following oral intake, the efficacy of nonprotein‐bound LA to function as a physiological antioxidant has been questioned. Herein, we review the evidence that the micronutrient functions of LA may be more as an effector of important cellular stress response pathways that ultimately influence endogenous cellular antioxidant levels and reduce proinflammatory mechanisms. This would promote a sustained improvement in cellular resistance to pathologies where oxidative stress is involved, which would not be forthcoming if LA solely acted as a transient ROS scavenger. © 2008 IUBMB IUBMB Life, 60(6): 362–367, 2008
Bcl‐2 family proteins: The sentinels of the mitochondrial apoptosis pathway
Authors: Wong W. Wei‐Lynn , Puthalakath Hamsa
Published: May 2008

Bcl‐2 family members are the arbiters of mitochondrial apoptotic pathway, which is conserved through evolution. The stoichiometry of pro‐ versus antiapoptotic Bcl‐2 family members in the cell determines whether the cell lives or dies. This fine balance is regulated at the transcriptional or posttranslational level in response to various cellular cues. These signals are transmitted through the upstream molecules in the pathway, that is, the BH3‐only molecules that results in the activation of the adaptor molecules, Bax and Bak, at the mitochondrial surface ensuing mitochondrial dysfunction and apoptosis. Understanding the activation process offers a great potential in the therapeutic intervention of many diseases such as cancer and autoimmune disorders. © 2008 IUBMB IUBMB Life, 60(6): 390–397, 2008
Prosaposin is an AR‐target gene and its neurotrophic domain upregulates AR expression and activity in prostate stromal cells
Authors: Koochekpour S. , Lee T.‐J. , Sun Y. , Hu S. , Grabowski G.A. , Liu Z. , Garay J.
Published: May 2008

Recent studies have introduced prosaposin (PSAP) as a pleiotrophic growth factor for prostate cancer (PCa). We have previously reported that PSAP or one of its known active molecular derivatives, saposin C functions as an androgen‐agonist and androgen‐regulated gene (ARG) for androgen‐sensitive (AS) PCa cell lines. Due to the potential significance of androgen receptor (AR)‐expressing stroma in PCa, we evaluated a possible bi‐directional paracrine regulatory interactions between DHT and PSAP in AR‐positive prostate stromal (PrSt) cells. We report that saposin C in a ligand‐independent manner increased AR expression, its nuclear content, and tyrosine phosphorylation. DHT treatment of PrSt cells increased PSAP expression. We also demonstrated both serum‐ and androgen‐inducibility of a previously characterized hormone‐responsive element (HRE) located in the proximal region of PSAP promoter. In addition, conditioned‐media derived from PrSt cells and bone fibroblasts (i.e., MSF) differentially increased PSAP‐promoter activity in androgen‐independent (AI) PC‐3 and AS LNCaP cells. Our data for the first time demonstrate that not only saposin C or PSAP regulates AR expression/activity, but also function as an ARG in PrSt. Ligand‐independent activation of AR by PSAP or saposin C in PCa and stromal cells may contribute not only to prostate carcinogenesis at an early stage, but also in AI progression of the disease in an androgen‐deprived tumor microenvironment. J. Cell. Biochem. 104: 2272–2285, 2008. © 2008 Wiley‐Liss, Inc.