bluuebunny/crossref_metadata_2025 huggingface dataset:
Raf‐1 expression may influence progression to androgen insensitive prostate cancer
Authors: Mukherjee R. , Bartlett J.M.S. , Krishna N.S. , Underwood M.A. , Edwards J.
Published: January 2005

BACKGROUND

Recent evidence has implicated the MAP kinase pathway with the development of androgen insensitive prostate cancer (AIPC). We have previously reported gene amplification of critical members of this pathway with the development of androgen insensitive disease.

METHODS

Protein expression of Raf‐1 was analyzed using immunohistochemistry (IHC) in a database of 65 paired tumor specimens obtained before and after the development of AIPC and correlated with other members of the pathway.

RESULTS

Patients whose Raf‐1 expression rose with development of AIPC had a significantly shorter median time to biochemical relapse compared to those whose expression fell or remained unchanged (1.16 vs. 2.62 years, P = 0.0005). In AIPC tumors, expression of Raf‐1 correlated significantly with expression of HER2 and with expression of c‐fos.

CONCLUSIONS

We conclude that the HER2/Raf‐1/AP‐1 axis may promote the development of AIPC, leading to early relapse. Members of the pathway may act as novel therapeutic targets for patients. © 2005 Wiley‐Liss, Inc.
Selective targeting of indel‐inferred differences in spatial structures of highly homologous proteins
Authors: Cherkasov Artem , Nandan Devki , Reiner Neil E.
Published: January 2005

Recent findings have shown that the protein elongation factor‐1α (EF‐1α) from the eukaryotic pathogen Leishmania donovani possesses virulence properties. This was unexpected, since it has greater than 80% sequence identity with its human homologue. Given that EF‐1α is essential for cell survival, in principle, it can be considered an attractive drug target. However, the challenge is to be able to selectively target the protein so as not to affect function of the human homologue. While a limited number of discrete differences were scattered throughout the sequence, most of the difference between these 2 homologues could be attributed to a 12–amino acid insert present in human EF‐1α and absent from the leishmania sequence. In the present study, we modeled the spatial differences in structures of human and L. donovani EF‐1α's inferred by this insertion–deletion (or “indel”). The protein models were used to develop antibodies directed specifically toward the deletion region of the pathogen protein. The strategy described allowed successful selective targeting of this putative leishmania virulence factor while avoiding recognition of the highly similar human EF‐1α homologue. These findings may establish a new strategy for the development of antagonists directed against certain pathogenic targets having close human homologues. Proteins 2005 © 2005 Wiley‐Liss, Inc.
A fuzzy clustering–ranking algorithm and its application for alarm operating optimization in chemical processing
Authors: Geng Zhiqiang , Zhu Qunxiong , Gu Xiangbai
Published: January 2005

Alarm overload in modern chemical plants presents many difficulties in decision and diagnosis. Management and optimization of alarm information are challenging work that must be confronted everyday. A new system alarm optimization technique, based on a fuzzy clustering–ranking (FCR) algorithm, is proposed according to the correlativity among process‐measured variables. The fuzzy clustering method is used to rationally group and cluster the information matrix of alarm variables to effectively decrease alarms under safety production. Moreover, the fuzzy difference driving (FDD) algorithm is used to rank the clustering center and alarm variables in every cluster, based on objective process characteristics. Furthermore, the validity of the proposed algorithm and solution is verified by application of a practical ethylene cracking furnace alarm system. The proposed method is an effective and reliable alarm‐management method that can optimize process operation and improve plant safety in the chemical industry. © 2005 American Institute of Chemical Engineers Process Saf Prog, 2005
Comparative acaricide susceptibility and detoxifying enzyme activities in field‐collected resistant and susceptible strains of Tetranychus urticae
Authors: Van Leeuwen Thomas , Van Pottelberge Steven , Tirry Luc
Published: January 2005

A field‐collected strain (MR‐VL) of the two‐spotted spider mite, Tetranychus urticae Koch, exhibited strong resistance to bifenthrin, dicofol and fenbutatin oxide in comparison with a susceptible laboratory strain (LS‐VL). The MR‐VL strain was screened for cross‐resistance with several currently used acaricides. Cross‐resistance was detected with clofentezine (RR = 2631), dimethoate (RR = 250), chlorfenapyr (RR = 154), bromopropylate (RR = 25), amitraz (RR = 17), flucycloxuron (RR = 15) and azocyclotin (RR = 7). Abamectin, acequinocyl, bifenazate, tebufenpyrad and spirodiclofen did not show any signs of cross‐resistance. Enhanced detoxification by increased activity of mono‐oxygenases (MO) and esterases is at least partially responsible for the observed resistance and cross‐resistance. MO assays with 7‐ethoxycoumarin (7‐EC) were optimised and 7‐ethoxy‐4‐trifluoromethylcoumarin (7‐EFC), a new MO‐substrate, was evaluated for the first time in T urticae and proved to be a good alternative to 7‐EC. Approximately 3‐ and 4‐fold higher MO activity was detected with 7‐EFC and 7‐EC respectively in the MR‐VL strain. Kinetic parameters of general esterase assays with 4‐nitrophenyl acetate and 1‐naphthyl acetate as substrate indicated that more esterases were present in the MR‐VL strain. A first attempt was made to classify the esterases present in T urticae. Acetyl‐, aryl‐ and carboxyl‐esterases were detected with the use of inhibitors after separation by native PAGE. Glutathione‐S‐transferases did not seem to play any role in the observed resistance and no differences were detected when the general oxidative capacities of the two strains were compared. Copyright © 2005 Society of Chemical Industry
Effect of hexaflumuron on mortality of the Western subterranean termite (Isoptera: Rhinotermitidae) during and following exposure and movement of hexaflumuron in termite groups
Authors: Haagsma Karl A , Rust Michael K
Published: January 2005

The effects of hexaflumuron consumption on the mortality of workers of the Western subterranean termite, Reticulitermes hesperus Banks, were observed following various exposures to a substrate treated with 14C‐labeled hexaflumuron at 5 g kg−1. Uptake of hexaflumuron by workers was rapid, peaking at approximately 280 ng hexaflumuron per termite 12 days after exposure. The onset of mortality began at day 8, with cumulative mortality reaching approximately 96% by day 45. Excretion of hexaflumuron from worker termites was rapid following various exposure periods, half‐lives ranging from 2.1 to 4.7 days. Trophallaxis among worker termites was efficient, hexaflumuron levels in recipient termites approaching two‐thirds of levels present in donor termites feeding continuously on hexaflumuron‐treated filter paper. The effect of donor‐to‐recipient group ratios was negligible on the amounts of hexaflumuron transferred from donors to recipients. In laboratory tests, hexaflumuron diffused from a feeding source within 7 days. The presence of additional food sources appeared to inhibit movement of hexaflumuron. Movement of hexaflumuron by cannibalism and coprophagy occurred, but was significant only when termites were starved. Hexaflumuron also appeared to adversely affect egg development by preventing hatch. Hexaflumuron was readily transferred through termite groups, effectively suppressing laboratory populations of R hesperus. Variable efficacy in field situations employing baiting with hexaflumuron in southern California may be a consequence of sporadic feeding at bait stations, the rapid clearance of hexaflumuron from individual termites, and the difficulties in bait presentation (low foraging activity, poor bait station foraging fidelity) inherent in the foraging characteristics of the Western subterranean termite. Copyright © 2005 Society of Chemical Industry
Negative ion electrospray mass spectra of the maculatin peptides from the tree frogs Litoria genimaculata and Litoria eucnemis
Authors: Brinkworth Craig S. , Bowie John H.
Published: January 2005

Collision‐induced fragmentations of deprotonated maculatin 1 peptides provide significant sequencing information. When the peptide lacks those residues which can fragment through their alpha side chains (e.g. Thr, Ser, Glu and Gln in this study) the basic α and β′ backbone cleavages occur from the [MH]− anion. When Thr, Ser, Glu and Gln are present, the ease of side‐chain fragmentation of these residues is: Thr (loss of MeCHO) > Ser (CH2O) > Glu (H2O) > Gln (NH3). When one of more of these residues is (are) present, the α and β′ cleavages often occur from a fragment rather than the [MH]− anion, e.g. for Thr, the [(MH)−MeCHO]− anion. These four residues also initiate γ backbone cleavage reactions. The relative abundances of peaks resulting from γ cleavage are Glu > Ser = Thr > Gln for maculatin 1 spectra. An unusual Gln19/Ile17 cyclisation/cleavage reaction occurs in maculatin spectra: the peptide [MH]− anion must adopt a helical conformation in order for these two groups to interact. Analogous fragmentations have been reported previously in the negative ion spectra of the caerin 1 peptides. Copyright © 2003 John Wiley & Sons, Ltd.
Analysis of tetracyclines in honey by high‐performance liquid chromatography/tandem mass spectrometry
Authors: Khong Seu‐Ping , Hammel Yves‐Alexis , Guy Philippe A.
Published: January 2005

A confirmatory method coupling liquid chromatography to tandem mass spectrometry (LC/MS/MS) is described for the determination of tetracycline, oxytetracycline, doxycycline and chlortetracycline in honey. Demeclocycline, another tetracycline molecule not reported for its usage in honey, was used as internal standard to quantify the four analytes. The sample preparation entails a clean‐up on an Oasis HLB solid‐phase extraction cartridge and analyses were realised by LC/MS/MS in selected reaction monitoring mode. The stability of tetracyclines was checked under various storage conditions at −20, +4 and +20°C (both under dark and light exposures). Indeed, tetracyclines are not stable molecules and the epimerisation phenomenon was evaluated in this work. Appropriate correction factors of the MS/MS responses of each epimer were studied for each of the four tetracyclines to accurately quantify them. Moreover, the matrix effects encountered during the LC/MS/MS analyses were also studied in spiked experiments from blank honey samples of various geographical origins and different flower types. Copyright © 2005 John Wiley & Sons, Ltd.
Ionization and fragmentation of N‐linked glycans as silver adducts by electrospray mass spectrometry
Authors: Harvey David J.
Published: January 2005

[M+Ag]+ ions were produced by electrospray from neutral high‐mannose, hybrid and complex N‐linked glycans obtained from bovine ribonuclease, chicken egg glycoproteins, bovine fetuin and porcine thyroglobulin by the addition of silver nitrate to the electrospray solvent. Both singly and doubly charged ions were produced but, as the signals were split between the two silver isotopes, sensitivity was not as high as with the sodium adducts reported earlier. Collision‐induced dissociation (CID) spectra were dominated by ions produced by glycosidic cleavages, mainly of the B‐ and Y‐type. Internal cleavage ions involving both B and Y cleavages were very prominent but cross‐ring fragments were generally of very low abundance or absent. Silver was very efficient at cleaving the glycosidic bonds, so much so that spectra tended to contain glycosidic ions at most possible combinations of the constituent monosaccharides. Copyright © 2005 John Wiley & Sons, Ltd.
A proof of a conjecture of Buck, Chan, and Robbins on the expected value of the minimum assignment
Authors: Wästlund Johan
Published: January 2005

We prove the main conjecture of the paper “On the expected value of the minimum assignment” by Marshall W. Buck, Clara S. Chan, and David P. Robbins [Random Structures Algorithms 21 (2002), 33–58]. This is an exact formula for the expected value of a certain type of random assignment problem. It generalizes the formula 1 + 1/4 + … 1/n2 for the n by n exp(1) random assignment problem. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2005
The effect of exercise on the intensity of low back pain in pregnant women
Authors: Garshasbi A. , Faghih Zadeh S.
Published: January 2005

Objective

To investigate the effect of exercise during pregnancy on the intensity of low back pain and kinematics of spine.

Method

A prospective randomized study was deigned. 107 women participated in an exercise program three times a week during second half of pregnancy for 12 weeks and 105 as control group. All filled a questionnaire between 17–22 weeks of gestation and 12 weeks later for assessment of their back pain intensity. Lordosis and flexibility of spine were measured by Flexible ruler and Side bending test, respectively, at the same times. Weight gain during pregnancy, Pregnancy length and neonatal weight were recorded.

Result

Low back pain intensity was increased in the control group. The exercise group showed significant reduction in the intensity of low back pain after exercise (p<0.0001). Flexibility of spine decreased more in the exercise group (p<0.0001). Weight gain during pregnancy, pregnancy length and neonatal weight were not different between the two groups.

Conclusion

Exercise during second half of the pregnancy significantly reduced the intensity of low back pain, had no detectable effect on Lordosis and had significant effect on flexibility of spine.
Oral misoprostol versus intracervical dinoprostone for induction of labor
Authors: Langenegger E.J. , Odendaal H.J. , Grové D.
Published: January 2005

Objectives: To compare oral misoprostol with dinoprostone for induction of labor and their effects on the fetal heart rate patterns. Methods: In a randomized controlled trial, 200 patients received either misoprostol 50 μg orally for every 4 h, or dinoprostone 0.5 mg intracervically for every 6 h. Cardiotocographic recordings, in 10‐min windows 30, 60, and 80 min after prostaglandin administration during induction and continuously during labor, were compared between the two groups. Primary outcome for effectiveness and safety was assessed in terms of the number of vaginal deliveries within 24 h and fetal heart rate abnormalities during induction and labor respectively. Results: Data from 96 patients in the misoprostol group and 95 in the dinoprostone group were analyzed. There were no significant differences in respect of the number of vaginal deliveries within 24 h (RR 1.12; 95% CI 0.88–1.42). The frequency of suspicious and pathological fetal heart rate patterns did not differ significantly but significantly more cardiotocographs in the dinoprostone group had non‐reassuring baseline variability 60 min after dose administration (RR 0.33; 95% CI 0.14–0.77). Maternal and neonatal outcomes did not differ significantly. Conclusion: Oral misoprostol is as effective as intracervical dinoprostone for induction of labor with no difference in the frequency of fetal heart rate abnormalities.
WHAT IS ARAB ISLAMIC RHETORIC? RETHINKING THE HISTORY OF MUSLIM ORATORY ART AND HOMILETICS
Authors: Halldén Philip
Published: January 2005

But about this same time, we were exposed to an even stranger kind of rhetoric, the rhetoric of the Middle Eastern world…. This was a rhetoric that seemed to play by none of the rules that had come down to us from a tradition of rhetoric that had been practiced by the reigning nations of the Western World for over 2000 years. And then there is the distinctive rhetoric of the Oriental world…. But those are rhetorics that we still have to study and analyze and codify.

—Edward P. J. Corbett, Classical Rhetoric for the Modern Student (1990), viii.
Does widowhood affect memory performance of older persons?
Authors: AARTSEN MARJA J. , VAN TILBURG THEO , SMITS CAROLIEN H. M. , COMIJS HANNIE C. , KNIPSCHEER KEES C. P. M.
Published: January 2005

Background. The loss of a spouse has been found to have a negative effect on physical and mental health and leads to increased mortality. Whether conjugal bereavement also affects memory functioning has largely been unexamined. The present study investigates the effect of widowhood on memory functioning in older persons.

Method. The sample consisted of 474 married women and 690 married men aged 60–85 years in 1992, followed up in 1995 and 1998. During the study 135 (28%) of the women and 69 (10%) of the men lost their spouse. Linear regression analysis was used to examine whether widowed men and women differed from those who had not been widowed in rate of memory change over 6 years. Cross-domain latent-change models were subsequently used to evaluate the extent to which changes in memory are related to changes in other domains of functioning that may be affected by widowhood.

Results. Older adults who lost a spouse during follow-up showed a greater decline in memory over 6 years than those who remained married. A higher level of depressive symptoms at baseline was related to lower levels of memory functioning and a greater decline. Memory decline was unrelated to changes in depressive symptoms and physical health.

Conclusions. Loss of the spouse is related to a greater decline in memory in older adults. The absence of an association with physical functioning and the weak association with mental functioning suggest that losing a spouse has an independent effect on memory functioning.
Memory and verbal learning functions in twins with bipolar-I disorder, and the role of information-processing speed
Authors: KIESEPPÄ TUULA , TUULIO-HENRIKSSON ANNAMARI , HAUKKA JARI , VAN ERP THEO , GLAHN DAVID , CANNON TYRONE D. , PARTONEN TIMO , KAPRIO JAAKKO , LÖNNQVIST JOUKO
Published: January 2005

Background. Euthymic bipolar-I disorder (BP I) patients and their siblings have shown impairments in verbal learning and memory functions compared with controls, suggesting that these impairments may be genetic in origin. Reduced information-processing speed has been associated with impaired memory in the elderly, and recently in schizophrenia. The authors compared verbal learning and memory functioning in twins with BP I and co-twins to control twins, and examined whether the observed deficits are related to information-processing speed.

Method. Finnish Medical and Population Registers and Twin Cohorts were used to identify the BP I and control twins. Neuropsychological tests assessing verbal learning and memory, working memory, facial recognition, visual memory, and information-processing speed were administered to 26 BP I twins, 19 non-bipolar co-twins, and 114 controls. Group differences were analyzed by generalized estimation equation modeling.

Results. BP I patients, but not co-twins, showed impairments in all memory tests compared with controls. Female co-twins showed impairment in verbal learning and memory. Information-processing speed had a significant effect on encoding and learning efficiency.

Conclusions. This study showed for the first time that information-processing speed is related to memory functioning and verbal learning in BP I in a population-based, representative and euthymic sample. Furthermore, the data support the view that defects in verbal memory may be related to the genetic factors predisposing to BP I in females.
Did Peter ever go to Rome?
Authors: Goulder Michael D.
Published: January 2005

Paul and Acts suggest that after Easter Peter lived in Jerusalem and had special responsibility for the mission to Palestine. 1 Clement mentions his two-plus labours (cf. Acts 3–4, 5, 12), but not Rome and not martyrdom. It places him second of seven chronologically ordered victims of jealousy between AD 40 and 70. Asc. Is. 4:2–3 is about Nero redivivus, not the historical Nero, and has nothing to do with Peter. By AD 100 legends were forming about his sojourn in Rome (1 Peter) and his martyrdom (John 21). He probably died in his bed in Jerusalem about AD 55.
Introduction
Authors: Crago Martha
Published: January 2005

This Special Issue of Applied Psycholinguistics contains a set of articles on research related to the genetics of developmental language disorders. The guest editors, Mabel Rice and Steven Warren, have assembled cross-disciplinary perspectives on the topic. In doing so, they highlight essential questions concerning the biological mechanism of innateness, the contributions of environment, the measurement of complex behavior, the nature of genetic structure, and the acquisition of language by various groups of young children. The intersection of these questions, one with another, provides a unique contribution of both theoretical and practical consequence for the field of psycholinguistics.
Moving toward a unified effort to understand the nature and causes of language disorders
Authors: RICE MABEL L. , WARREN STEVEN F.
Published: January 2005

The nature and causes of language disorders are research topics familiar to the readership ofApplied Psycholinguistics. Current inquiries place these topics in a dynamic and sprawling multidisciplinary context manifested through investigations of linguistic acquisition, cognitive development, genetics, neurocortical processes, cognitive neurolinguistics, behavioral phenotypes, and language intervention. This list is not complete by any means, but it does suggest the wide front of the current search for better knowledge about what causes language disorders and the dimensions of language acquisition that are affected. Although there is considerable momentum underway in current inquiries, the full potential for scientific advancement is hampered by fragmentation in the field, in part attributable to partitioning by diagnostic categories of affectedness. Investigators (and their funding sources) often focus on a particular clinical group, such as specific language impairment (SLI), autism/autism spectrum disorders (ASD), Williams syndrome (WS), Down syndrome (DS), or fragile X syndrome (FXS). Although this is not exclusively the case, it is relatively difficult to carry out comparative studies across the multiple clinical conditions in which language disorders appear and to monitor developments across such a wide front of investigation. The consequence is that findings are distributed across different publication outlets and different groups of scholars, a situation that can limit our appreciation of the ways in which language disorders are manifest, and the identification of common etiological factors.
Language symptoms of developmental language disorders: An overview of autism, Down syndrome, fragile X, specific language impairment, and Williams syndrome
Authors: RICE MABEL L. , WARREN STEVEN F. , BETZ STACY K.
Published: January 2005

Language deficits occur in a variety of developmental disorders including autism spectrum disorders, Down syndrome, fragile X syndrome, specific language impairment, and Williams syndrome. This paper describes the specific pattern of linguistic deficits in each of these disorders in terms of speech production, semantic, and syntactic abilities as well as the relationship between cognitive and linguistic skills and the presence of a deviant or delayed pattern of development. In the spirit of synthesis across diverse literatures, preliminary comparisons among the language profiles of these disorders are made. The full picture, however, is incomplete given the current state of the literature, which tends to focus on the analysis of a narrow range of linguistic phenomena within a single disorder. The field is in need of research that systematically compares these disorders and leads to detailed descriptions of linguistic phenotypes of each disorder.
Electrophysiology in the study of developmental language impairments: Prospects and challenges for a top-down approach
Authors: PHILLIPS COLIN
Published: January 2005

There is a good deal of interest in the application of neurocognitive techniques to investigate the underpinnings of developmental language impairments (DLIs). Electrophysiological techniques such as electroencephalography and magnetoencephalography offer the promise of the ability to track brain activity with precision in time and space. This article describes a number of findings from studies of normal adults and children that are relevant to neurocognitive studies of developmental language impairments and outlines a series of challenges that should be met in order for electrophysiological measures to realize their promise.
Planning studies of etiology
Authors: SMITH SHELLEY D. , MORRIS COLLEEN A.
Published: January 2005

Knowledge of the environmental and genetic etiologies of complex cognitive disorders can guide strategies for diagnosis, prevention, and therapy, but disentangling the various causes can be very challenging. Two basic approaches can be used in identifying genetic factors, a top-down approach, in which phenotypic descriptions are used to discover genes that influence those phenotypes, and a bottom-up approach, comparing the phenotypic effects of genes that are known to cause syndromes that include cognitive disabilities. Thorough characterization of phenotypes throughout development is critical to both of these methods. These strategies have been applied to the characterization of genetic etiologies for reading disability, language disorders, attention-deficit hyperactivity disorder, and autism.
Dissection of molecular mechanisms underlying speech and language disorders
Authors: FISHER SIMON E.
Published: January 2005

Developmental disorders affecting speech and language are highly heritable, but very little is currently understood about the neuromolecular mechanisms that underlie these traits. Integration of data from diverse research areas, including linguistics, neuropsychology, neuroimaging, genetics, molecular neuroscience, developmental biology, and evolutionary anthropology, is becoming essential for unraveling the relevant pathways. Recent studies of theFOXP2gene provide a case in point. Mutation ofFOXP2causes a rare form of speech and language disorder, and the gene appears to be a crucial regulator of embryonic development for several tissues. Molecular investigations of the central nervous system indicate that the gene may be involved in establishing and maintaining connectivity of corticostriatal and olivocerebellar circuits in mammals. Notably, it has been shown thatFOXP2was subject to positive selection in recent human evolution. Consideration of findings from multiple levels of analysis demonstrates thatFOXP2cannot be characterized as “the gene for speech,” but rather as one critical piece of a complex puzzle. This story gives a flavor of what is to come in this field and indicates that anyone expecting simple explanations of etiology or evolution should be prepared for some intriguing surprises.
Spectral and angular characterization of laser-produced proton
beams from dosimetric measurements
Authors: BRESCHI E. , BORGHESI M. , CAMPBELL D. H. , GALIMBERTI M. , GIULIETTI D. , GIZZI L. A. , ROMAGNANI L. , SCHIAVI A. , WILLI O.
Published: January 2005

In this paper, we report the first results of dosimetric analysis of
broad-spectrum, multi-MeV laser accelerated proton beams obtained
during experiments at the Rutherford Appleton Laboratory using the
Chirped Pulse beam of the Vulcan laser. The spectra are retrieved by a
numerical analysis that allows the reconstruction of the energetic
profile of the proton beam from data obtained using radiochromic
film.
Coupling of longitudinal and transverse motion of accelerated
electrons in laser wakefield acceleration
Authors: REITSMA A.J.W. , JAROSZYNSKI D.A.
Published: January 2005

The acceleration dynamics of electrons in a laser wakefield
accelerator is discussed, in particular the coupling of longitudinal
and transverse motion. This coupling effect is important for electrons
injected with a velocity below the laser pulse group velocity. It is
found that the electron bunch is adiabatically focused during the
acceleration and that a finite bunch width contributes to bunch
lengthening and growth of energy spread. These results indicate the
importance of a small emittance for the injected electron bunch.
A study of the parameters of particles ejected from a laser plasma
Authors: DORIA D. , LORUSSO A. , BELLONI F. , NASSISI V. , TORRISI L. , GAMMINO S.
Published: January 2005

We report on the results concerning the characteristics and the
behavior of expanding plasma generated by a Laser Ion Source (LIS). The
LIS technique is an efficient means in producing of multi-charged ions
utilizing pulsed laser beams. In order to extract Cu ions, in this
experiment an XeCl excimer UV laser was employed, providing a power
density on the target surface up to 5 × 108
W/cm2. Two typologies of diagnostic systems were
developed in order to detect the plasma current and the ion energy. The
time-of-flight (TOF) measurements were performed exploiting either a
Faraday cup or an Ion Energy Analyzer (IEA). This latter allowed
getting quantitative information about the relative ion abundances,
their kinetic energy and their charge state. To study the plasma
characteristics we measured the total etched material per pulse at 70
mJ. It was 0.235 μg and the overall degree of ionization, 16%. The
angular distribution of the ablated material was monitored by optical
transmission analysis of the deposited film as a function of the angle
with respect to the normal to the target surface. Applying a high
voltage to an extraction gap a multi-charged ion beam was obtained;
different peaks could be distinguished in the TOF spectrum, resulting
from the separation of ions of hydrogen, adsorbed compounds in the
target and copper.
Fusion cross-sections for inertial fusion energy
Authors: LI XING ZHONG , LIU BIN , CHEN SI , WEI QING MING , HORA HEINRICH
Published: January 2005

The application of selective resonant tunneling model is extended
from d + t fusion to other light nucleus fusion reactions, such as d +
d fusion and d + 3He. In contrast to traditional formulas,
the new formula for the cross-section needs only a few parameters to
fit the experimental data in the energy range of interest. The features
of the astrophysical S-function are derived in terms of this model. The
physics of resonant tunneling is discussed.
Quantum effects in laser-beam Compton interaction and stimulated
electron-positron annihilation in a strong field
Authors: SMETANIN I.V. , NAKAJIMA K.
Published: January 2005

Quantum effects in spontaneous and stimulated Compton laser-beam
interactions are considered in the frame of the Klein–Gordon
theory. We derive a quantum kinetic equation to describe the laser
cooling of electron beams. Nonlinear theory of coherent π-pulse
generation in the quantum X-ray Compton FEL is presented. A scheme of
coherent stimulated annihilation of electron-positron pairs and
stimulated emission of γ-ray photons is proposed.
Developments in inertial fusion energy and beam fusion at magnetic confinement
Authors: HORA HEINRICH
Published: January 2005

The 70-year anniversary of the first nuclear fusion reaction of hydrogen isotopes by Oliphant, Harteck, and Rutherford is an opportunity to realize how beam fusion is the path for energy production, including both branches, the magnetic confinement fusion and the inertial fusion energy (IFE). It is intriguing that Oliphant's basic concept for igniting controlled fusion reactions by beams has made a comeback even for magnetic confinement plasma, after this beam fusion concept was revealed by the basically nonlinear processes of the well-known alternative of inertial confinement fusion using laser or particle beams. After reviewing the main streams of both directions some results are reported—as an example of possible alternatives—about how experiments with skin layer interaction and avoiding relativistic self-focusing of clean PW–ps laser pulses for IFE may possibly lead to a simplified fusion reactor scheme without the need for special compression of solid deuterium–tritium fuel.
Parameters of a fast ion jet generated by an intense ultrashort
laser pulse on an inhomogeneous plasma foil
Authors: ANDREEV A.A. , OKADA T. , PLATONOV K.Yu. , TORAYA S.
Published: January 2005

Analysis and simulations of fast particles produced by a
high-intensity short laser pulse interacting with a foil target are
performed. Initially, the plasma density distribution of the foil
target has a smooth gradient with the scale length of plasma density
varying across it. The absorbed laser energy is transferred to fast
electrons, which penetrate in the foil and are partially ejected from
the foil rear. These electrons produce an electric field that causes an
ion beam to be emitted from the foil. We analyze the mechanism of ion
acceleration in the foil plasma and the influence of the density
gradient and other laser and plasma parameters on ion acceleration. The
angular distributions of the ejected electrons and ions are
calculated.
No doubt about offset latency
Authors: BAIR WYETH
Published: January 2005

Neuronal response latency usually refers to the time between the presentation of a visual stimulus and the elevation in firing rate that follows. Expanding on this idea, the concept of response offset latency refers to the time between the removal of a stimulus (or its replacement with one that is less effective) and the resulting decline in firing rate. The initial observation that offset latency is usually shorter than onset latency (Bair et al., 2002) has been called into question on the basis of the pulsatile nature of visual stimuli presented on a CRT (Gawne & Woods, 2003). Here, a counter argument is presented in support of the results of Bair et al., 2002.
Color vision sensitivity in normally dichromatic species and humans
Authors: VAN ARSDEL RICHARD E. , LOOP MICHAEL S.
Published: January 2005

Spectral-sensitivity functions for large, long-duration increments presented on a photopic white background indicate that wavelength-opponent mechanisms mediate detection in both normal and dichromatic humans. Normal humans exhibit high color-vision sensitivity as they discriminate the color of spectral flashes at detection-threshold intensities. However, dichromatic humans require stimuli up to about 0.4 log units above detection intensity to see certain colors. This low color-vision sensitivity in human dichromats may be an abnormal condition involving a defect in postreceptoral color processing. To test this hypothesis, we determined color-discrimination thresholds in normally dichromatic species: chipmunk, 13-lined ground squirrel, and tree shrew. For comparison, we also tested humans with normal and abnormal (deutan) color vision with the same apparatus and methods. Animals were trained to perform spatial two-choice discrimination tasks for food reward. Detection thresholds were determined for increments of white, 460 nm, 540 nm, 560 nm, 580 nm, 500 nm/long-pass, and 500 nm/short-pass on white backgrounds of 1.25 cd/m2, 46 cd/m2, and 130 cd/m2. Animals were also trained to respond to the colored increments when paired with the white increment when both were at equally detectable intensities Color-discrimination thresholds were determined by dimming stimulus pairs (coloredvs. white) until the subjects could no longer make the discriminations. Results indicated that the normally dichromatic species could discriminate colored stimuli from white at a mean intensity of 0.1 (±0.1) log units above detection threshold. The ability of normally dichromatic species to discriminate color near detection-threshold intensity is consistent with increment spectral-sensitivity functions that indicate detection by wavelength-opponent mechanisms. In keeping with previous studies, normal human trichromats discriminated color near detection-threshold intensities but humans with deutan color vision required suprathreshold intensities to discriminate the color of middle and long wavelengths. This high color-vision sensitivity of normally dichromatic species suggests that the low color-vision sensitivity in dichromatic humans is an abnormal condition and indicates a possible defect in their postreceptoral color-vision processing.
Transmission of single photon signals through a binary synapse in the mammalian retina
Authors: BERNTSON AMY , SMITH ROBERT G. , TAYLOR W. ROWLAND
Published: January 2005

At very low light levels the sensitivity of the visual system is determined by the efficiency with which single photons are captured, and the resulting signal transmitted from the rod photoreceptors through the retinal circuitry to the ganglion cells and on to the brain. Although the tiny electrical signals due to single photons have been observed in rod photoreceptors, little is known about how these signals are preserved during subsequent transmission to the optic nerve. We find that the synaptic currents elicited by single photons in mouse rod bipolar cells have a peak amplitude of 5–6 pA, and that about 20 rod photoreceptors converge upon each rod bipolar cell. The data indicates that the first synapse, between rod photoreceptors and rod bipolar cells, signals a binary event: the detection, or not, of a photon or photons in the connected rod photoreceptors. We present a simple model that demonstrates how a threshold nonlinearity during synaptic transfer allows transmission of the single photon signal, while rejecting the convergent neural noise from the 20 other rod photoreceptors feeding into this first synapse.
Functionally intact glutamate-mediated signaling in bipolar cells of the TRKB knockout mouse retina
Authors: ROHRER BAERBEL , BLANCO ROMAN , MARC ROBERT E. , LLOYD MARCIA B. , BOK DEAN , SCHNEEWEIS DAVID M. , REICHARDT LOUIS F.
Published: January 2005

In the juvenile trkB knockout (trkB−/−) mouse, retina synaptic communication from rods to bipolar cells is severely compromised as evidenced by a complete absence of electroretinogram (ERG)b-wave, even though the inner retina appears anatomically normal (Rohrer et al., 1999). Since it is well known that theb-wave reflects light-dependent synaptic activation of ON bipolar cellsviatheir metabotropic glutamate receptor, mGluR6, we sought to analyze the anatomical and functional integrity of the glutamatergic synapses at these and other bipolar cells in thetrkB−/−mouse. Although rod bipolar cells from wild-type juvenile mice were determined to be immunopositive for trkB, postsynaptic metabotropic and ionotropic glutamate receptor-mediated pathways in ON and OFF bipolar cells were found to be functionally intact, based on patch electrode recordings, using brief applications (“puffs”) of glutamate or its analog, 2-amino-4-phosphonobutyric acid (APB), a selective agonist for mGluR6 receptors. Ionotropic glutamate receptor function was assayed in OFF-cone bipolar and horizontal cells by applying exogenous glutamatergic agonists in the presence of the channel-permeant guanidinium analogue, 1-amino-4-guanidobutane (AGB). Electron-microscopic analysis revealed that the ribbon synapses between rods and postsynaptic rod bipolar and horizontal cells were formed at the appropriate age and appear to be structurally intact, and immunohistochemical analysis did not detect profound defects in the expression of excitatory amino acid transporters involved in glutamate clearance from the synaptic cleft. These data indicate that there does not appear to be evidence for postsynaptic deficits in glutamatergic signaling in the ON and OFF bipolar cells of mice lacking trkB.
Decorrelation of neural activity during fixational instability: Possible implications for the refinement of V1 receptive fields
Authors: RUCCI MICHELE , CASILE ANTONINO
Published: January 2005

Early in life, visual experience appears to influence the refinement and maintenance of the orientation-selective responses of neurons in the primary visual cortex. After eye opening, the statistical structure of visually driven neural responses depends not only on the stimulus, but also on how the stimulus is scanned during behavior. Modulations of neural activity due to behavior may thus play a role in the experience-dependent refinement of cell response characteristics. To investigate the possible influences of eye movements on the maturation of thalamocortical connectivity, we have simulated the responses of neuronal populations in the lateral geniculate nucleus (LGN) and V1 of the cat while images of natural scenes were scanned in a way that replicated the cat's oculomotor activity. In the model, fixational eye movements were essential to attenuate neural sensitivity to the broad correlational structure of natural visual input, decorrelate neural responses, and establish a regime of neural activity that was compatible with a Hebbian segregation of geniculate afferents to the cortex. We show that this result is highly robust and does not depend on the precise characteristics of the model.
Normal photoresponses and alteredb-wave responses to APB in themdxCv3mouse isolated retina ERG supports role for dystrophin in synaptic transmission
Authors: GREEN DANIEL G. , GUO HAO , PILLERS DE-ANN M.
Published: January 2005

ThemdxCv3mouse is a model for Duchenne muscular dystrophy (DMD). DMD is an X-linked disorder with defective expression of the protein dystrophin, and which is associated with a reducedb-wave and has other electro- retinogram (ERG) abnormalities. To assess potential causes for the abnormalities, we recorded ERGs from pieces of isolated C57BL/6J andmdxCv3mouse retinas, including measurements of transretinal and intraretinal potentials. The ERGs from the isolatedmdxCv3retina differ from those of control retinas in that they show reducedb-wave amplitudes and increasedb-wave implicit times. Photovoltages obtained by recording across the photoreceptor outer segments of the retinas did not differ from normal, suggesting that the likely causes of the reducedb-wave are localized to the photoreceptor to ON-bipolar synapse. At a concentration of 50 μM, the glutamate analog DL-2-amino-4-phosphonobutyric acid (APB) blocks theb-wave component of the ERG, by binding to sites on the postsynaptic membrane. The On-bipolar cell contribution to the ERG was inferred by extracting the component that was blocked by APB. We found that this component was smaller in amplitude and had longer response latencies in themdxCv3mice, but was of similar overall time course. To assess the sensitivity of sites on the postsynaptic membrane to glutamate, the concentration of APB in the media was systematically varied, and the magnitude of blockage of the light response was quantified. We found that themdxCv3retina was 5-fold more sensitive to APB than control retinas. The ability of lower concentrations of APB to block theb-wave inmdxCv3suggests that the ERG abnormalities may reflect alterations in either glutamate release, the glutamate postsynaptic binding sites, or in other proteins that modulate glutamate function in ON-bipolar cells.
Central regulation of photosensitive membrane turnover in the lateral eye ofLimulus. II. Octopamine actsviaadenylate cyclase/cAMP-dependent protein kinase to prime the retina for transient rhabdom shedding
Authors: RUNYON SCOTT L. , WASHICOSKY KEVIN J. , BRENNEMAN* RANDALL J. , KELLY JEREMY R. , KHADILKAR RASHMI V. , HEACOCK KEVIN F. , MCCORMICK SHAELAN M. , WILLIAMS KELLY E. , JINKS ROBERT N.
Published: January 2005

Why photoreceptors turn over a portion of their photoreceptive membrane daily is not clear; however, failure to do so properly leads to retinal degeneration in vertebrates and invertebrates. Little is known about the molecular mechanisms that regulate shedding and renewal of photoreceptive membrane. Photoreceptor cells in the lateral eye of the horseshoe crabLimulusturn over their photoreceptive membrane (rhabdom) in a brief, synchronous burst in response to dawn each morning. Transient rhabdom shedding (TRS), the first phase of rhabdom turnover inLimulus, is triggered by dawn, but requires a minimum of 3–5 h of overnight priming from the central circadian clock (Chamberlain & Barlow, 1984). We determined previously that the clock primes the lateral eye for TRS using the neurotransmitter octopamine (OA) (Khadilkar et al., 2002), and report here that OA primes the eye for TRS through a Gs-coupled, adenylate cyclase (AC)/cyclic adenosine 3′,5′-monophosphate (cAMP)/cAMP-dependent protein kinase (PKA) signaling cascade. Long-term intraretinal injections (6–7 h @ 1.4 μl/min) of the AC activator forskolin, or the cAMP analogs Sp-cAMP[S] and 8-Br-cAMP primed the retina for TRS in eyes disconnected from the circadian clock, and/or in intact eyes during the day when the clock is quiescent. This suggests that OA primes the eye for TRS by stimulating an AC-mediated rise in intracellular cAMP concentration ([cAMP]i). Co-injection of SQ 22,536, an AC inhibitor, or the PKA inhibitors H-89 and PKI (14-22) with OA effectively antagonized octopaminergic priming by reducing the number of photoreceptors primed for TRS and the amount of rhabdom shed by those photoreceptors compared with eyes treated with OA alone. Our data suggest that OA primes the lateral eye for TRS in part through long-term phosphorylation of a PKA substrate.
Vision in the southern hemisphere lampreyMordacia mordax: Spatial distribution, spectral absorption characteristics, and optical sensitivity of a single class of retinal photoreceptor
Authors: COLLIN SHAUN P. , HART NATHAN S. , WALLACE KATE M. , SHAND JULIA , POTTER IAN C.
Published: January 2005

The dorso-laterally located eyes of the southern hemisphere lampreyMordacia mordax(Agnatha) contain a single morphological type of retinal photoreceptor, which possesses ultrastructural characteristics of both rods and cones. This photoreceptor has a large refractile ellipsosome in the inner segment and a long cylindrical outer segment surrounded by a retinal pigment epithelium that contains two types of tapetal reflectors. The photoreceptors form a hexagonal array and attain their peak density (33,200 receptors/mm2) in the ventro-temporal retina. Using the size and spacing of the photoreceptors and direct measures of aperture size and eye dimensions, the peak spatial resolving power and optical sensitivity are estimated to be 1.7 cycles deg−1(minimum separable angle of 34′7′′) and 0.64 μm2steradian (white light) and 1.38 μm2steradian (preferred wavelength or λmax), respectively. Microspectrophotometry reveals that the visual pigment located within the outer segment is a rhodopsin with a wavelength of maximum absorbance (λmax) at 514 nm. The ellipsosome has very low absorptance (<0.05) across the measured spectrum (350–750 nm) and probably does not act as a spectral filter. In contrast to all other lampreys studied, the optimized receptor packing, the large width of the ellipsosome-bearing inner segment, together with the presence of a retinal tapetum in the photophobicMordacia, all represent adaptations for low light vision and optimizing photon capture.