bluuebunny/crossref_metadata_2025 huggingface dataset:
Differential synaptic organization of GABAergic bipolar cells and non‐GABAergic (glutamatergic) bipolar cells in the tiger salamander retina
Authors: Yang Chen‐Yu , Zhang Jun , Yazulla Stephen
Published: October 2004

The synaptic organizations of γ‐aminobutyric acid–immunoreactive (GABA‐IR, GABAergic) and non–GABA‐IR (non‐IR, glutamatergic) bipolar cells in salamander retina were compared by postembedding immunoelectron microscopy. A total of 238 presynaptic bipolar cell synapses were studied; 61 were GABA‐IR and 177 were non‐IR. Both groups were similar in that (1) they made asymmetrical ribbon synapses as well as asymmetrical non‐ribbon synapses; (2) they made ribbon synapses at dyads, triads, and monads; and (3) the vast majority of ribbon synapses (∼90%) were with dyads. The differences were that synapses of GABA‐IR bipolar cells had a higher proportion of (1) direct contact with ganglion cells, (2) non‐ribbon synapses, (3) output to GABA‐IR amacrine cells, and (4) output in sublamina a. Overall, the output of GABA‐IR ribbons was equally split between amacrine and ganglion cell processes, whereas for non‐IR ribbons, it was approximately 2:1 in favor of amacrine cells. The ribbon:non‐ribbon synapse ratio was approximately 1.2:1 (33:28) for GABA‐IR but approximately 2:1 (118:59) for non‐IR terminals. Thus, GABA‐IR bipolar cells made more direct contacts with ganglion cells and used a higher proportion of non‐ribbon synapses. GABA‐IR dyads were more likely to contact GABA‐IR amacrine profiles (52% vs. 38%). Finally, GABA‐IR ribbon synapses were more common in sublamina a than sublamina b (2:1), whereas non‐IR synapses were equally present in sublaminas a and b. This differential targeting of ganglion cells and amacrine cells in the OFF vs. ON layers indicates a difference in the role of bipolar cells in the generation of receptive field properties, depending on whether or not they use GABA as well as glutamate for their transmitter. J. Comp. Neurol. 455:187–197, 2003. © 2002 Wiley‐Liss, Inc.
Anomalous scaling for three‐dimensional Cahn‐Hilliard fronts
Authors: Korvola Timo , Kupiainen Antti , Taskinen Jari
Published: October 2004

We prove the stability of the one‐dimensional kink solution of the Cahn‐Hilliard equation under d‐dimensional perturbations for d ≥ 3. We also establish a novel scaling behavior of the large‐time asymptotics of the solution. The leading asymptotics of the solution is characterized by a length scale proportional to t1/3 instead of the usual t1/2 scaling typical to parabolic problems. © 2004 Wiley Periodicals, Inc.
Caloric restriction for longevity: II—The systematic neglect of behavioural and psychological outcomes in animal research
Authors: Vitousek Kelly M. , Manke Frederic P. , Gray Jennifer A. , Vitousek Maren N.
Published: October 2004

Research on caloric restriction for longevity (CRL) has generated hundreds of articles on the physiology of food deprivation, yet almost no data on consequences in other domains. The first paper in this series outlined the generally positive physical effects of CRL; the second analyses the meagre and sometimes disturbing record of research on behaviour, cognition and affect. The available evidence suggests that nutrient‐dense CRL in animals—just like nutrient‐poor semi‐starvation in people—is associated with a number of adverse effects. Changes include abnormal food‐related behaviour, heightened aggression and diminished sexual activity. Studies of learning and memory in underfed rodents yield inconsistent findings; no information is available on cognitive effects in primates. To date, the CRL field has ignored other variables that are crucial to the human case and known to be disrupted by chronic hunger, including sociability, curiosity and emotionality. Promotion of CRL for people is irresponsible in the absence of more reassuring data on the full range of expected outcomes. Eating disorder specialists should be contributing to scientific and public discussions of this increasingly prominent paradigm. Copyright © 2004 John Wiley & Sons, Ltd and Eating Disorders Association.
Colocalization of WT1 and cell proliferation reveals conserved mechanisms in temperature‐dependent sex determination
Authors: Schmahl Jennifer , Yao Humphrey H. , Pierucci‐Alves Fernando , Capel Blanche
Published: October 2004

Summary: During vertebrate development the gonad has two possible fates, the testis or the ovary. The choice between these fates is made by a variety of sex‐determining mechanisms, from the sex‐determining gene on the Y chromosome (Sry) in mammals, to nongenetic temperature‐dependent systems in many reptiles. Despite the differences in the mechanisms at the top of the sex‐determining cascade, the resulting morphology and many genes involved in early testis and ovarian development are common to most vertebrates, leading to the hypothesis that the underlying processes of sex determination are conserved. In this study, we examined the early steps of gonad development in the red‐eared slider turtle (Trachemys scripta), a species that uses the temperature of egg incubation to determine sex. A dramatic increase in cell proliferation was observed in the male gonad during the earliest stages of sex determination. Using the localization of Wilms' Tumor suppressor 1 (WT1), we determined that this proliferation increase occurred in a population that contained pre‐Sertoli cells. The proliferation of pre‐Sertoli cells has been documented during sex determination in both mice and alligators, suggesting that proliferation of this cell type has an important role in vertebrate testis organogenesis and the determination of male fate. genesis 35:193–201, 2003. © 2003 Wiley‐Liss, Inc.
BMP ligands act redundantly to pattern the dorsal telencephalic midline
Authors: Hébert Jean M. , Hayhurst Monica , Marks Melissa E. , Kulessa Holger , Hogan Brigid L.M. , McConnell Susan K.
Published: October 2004

The embryonic telencephalon is patterned into several areas that give rise to functionally distinct structures in the adult forebrain. Previous studies have shown that BMP4 and BMP2 can induce features characteristic of the telencephalic midline in cultured explants, suggesting that the normal role of BMP4 in the forebrain is to pattern the medial lateral axis of the telencephalon by promoting midline cell fates. To test this hypothesis directly in vivo, the Bmp4 gene was efficiently disrupted in the telencephalon using a CRE/loxP approach. Analysis of Bmp4‐deficient telencephalons fails to reveal a defect in patterning, cell proliferation, differentiation, or apoptosis. The absence of a phenotype in the Bmp4‐deficient telencephalon along with recent genetic studies establishing a role for a BMP4 receptor, BMPRIA, in telencephalic midline development, demonstrate that loss of Bmp4 function in the telencephalon can be compensated for by at least one other Bmp gene, the identity of which has not yet been determined. genesis 35:214–219, 2003. © 2003 Wiley‐Liss, Inc.
Genetic screen for small body size mutants in C. elegans reveals many TGFβ pathway components
Authors: Savage‐Dunn Cathy , Maduzia Lisa L. , Zimmerman Cole M. , Roberts Andrew F. , Cohen Stephen , Tokarz Rafal , Padgett Richard W.
Published: October 2004

In the nematode Caenorhabditis elegans, a TGFβ‐related signaling pathway regulates body size and male tail morphogenesis. We sought to identify genes encoding components or modifiers of this pathway in a large‐scale genetic screen. Remarkably, this screen was able to identify essentially all core components of the TGFβ signaling pathway. Among 34 Small mutants, many mutations disrupt genes encoding recognizable components of the TGFβ pathway: DBL‐1 ligand, DAF‐4 type II receptor, SMA‐6 type I receptor, and SMA‐2, SMA‐3, and SMA‐4 Smads. Moreover, we find that at least 11 additional complementation groups can mutate to the Small phenotype. Four of these 11 genes, sma‐9, sma‐14, sma‐16, and sma‐20 affect male tail morphogenesis as well as body size. Two genes, sma‐11 and sma‐20, also influence regulation of the developmentally arrested dauer larval stage, suggesting a role in a second characterized TGFβ pathway in C. elegans. Other genes may represent tissue‐specific factors or parallel pathways for body size control. Because of the conservation of TGFβ signaling pathways, homologs of these genes may be involved in tissue specificity and/or crosstalk of TGFβ pathways in other animals. genesis 35:239–247, 2003. © 2003 Wiley‐Liss, Inc.
Analysis of 5′ nucleotidase and alkaline phosphatase by gene disruption in Dictyostelium
Authors: Rutherford Charles L. , Overall Danielle F. , Ubeidat Muatasem , Joyce Bradley R.
Published: October 2004

Summary: In Dictyostelium discoideum a phosphatase with a high pH optimum is known to increase in activity during cell differentiation and become localized to a narrow band of cells at the interface of prespore and prestalk cells. However, it was not clear if this activity is due to a classical “alkaline phosphatase” with broad range substrate specificity or to a “5′nucleotidase” with high substrate preference for 5′AMP. We attempted to disrupt the genes encoding these two phosphatase activities in order to determine if the activity that is localized to the interface region resides in either of these two proteins. During aggregation of 5nt null mutants, multiple tips formed rather than the normal single tip for each aggregate. In situ phosphatase activity assays showed that the wt and the 5nt gene disruption clones had normal phosphatase activity in the area between prestalk and prespore cell types, while the alp null mutants did not have activity in this cellular region. Thus, the phosphatase activity that becomes localized to the interface of the prestalk and prespore cells is alkaline phosphatase. genesis 35:202–213, 2003. © 2003 Wiley‐Liss, Inc.
Tissue‐specific developmental requirements of Drosophila tyrosine hydroxylase isoforms
Authors: Friggi‐Grelin Florence , Iché Magali , Birman Serge
Published: October 2004

Summary: Drosophila tyrosine hydroxylase (DTH) is a key enzyme in dopamine (DA) biosynthesis, which is expressed in neural and hypodermal DA‐synthesizing cells. We previously reported that two DTH isoforms are produced in flies through tissue‐specific alternative splicing that show distinct regulatory properties. We have now selectively expressed each DTH isoform in vivo in a pale (ple, i.e., DTH‐deficient) mutant background. We show that the embryonic lethality of ple can be rescued by expression of the hypodermal, but not the neural, DTH isoform in all DA cells, indicating that the hypoderm‐ isoform is absolutely required for cuticle biosynthesis and survival in Drosophila. In addition, we report new observations on the consequences of DTH overexpression in the CNS and hypoderm. Our results provide evidence that tissue‐specific alternative splicing of the DTH gene is a vital process in Drosophila development. genesis 35:260–269, 2003. © 2003 Wiley‐Liss, Inc.
The psychosocial aspects of donating blood stem cells: The sibling donor perspective
Authors: Williams Susan , Green Rachel , Morrison Anne , Watson Douglas , Buchanan Sister Susan
Published: October 2004

The collection of peripheral blood progenitor cells (PBPC) by apheresis has become common in related allogeneic donors. However, the acceptability of the procedure to donors has not been documented. The purpose of this baseline case series study was to evaluate the psycho‐social dimensions of apheresis from the perspective of healthy sibling donors and to explore issues surrounding fully informed consent including voluntary donation. At the first interview to discuss donation, 17 consecutive human leucocyte antigens (HLA) identical sibling donors who chose to donate PBPC were recruited to the study. They then completed both scales of the State‐Trait Anxiety Inventory. The state scale was completed again immediately before first apheresis. At the end of the final apheresis, the donors were interviewed again by an independent researcher using a standardised questionnaire. All aspects of the procedure were well tolerated, including levels of anxiety and pain. Donors donated even if the relationship with their sibling was poor. However, some areas for improvement were highlighted. Eight (47%) donors were asked to donate by their sibling or another close relative, and this gave them no real volunteer status. Written information was judged important by 11 (65%) donors, but the material used was limited. The possibility of a poor outcome for the recipient was not well understood. The content of the written documentation and the management of confidentiality in terms of donor volunteer status needed to be addressed. A further study regarding the follow‐up needs of donors, including those where the outcome is poor, is underway. J. Clin. Apheresis 18:1–9, 2003. © 2003 Wiley‐Liss, Inc.
Modification of the leukapheresis procedure for use in rhesus monkeys (Macaca mulata)
Authors: Ageyama Naohide , Kimikawa Masaaki , Eguchi Kei , Ono Fumiko , Shibata Hiroaki , Yoshikawa Yasuhiro , Terao Keiji
Published: October 2004

One of the most serious problems in applying leukapheresis to human infants is the large extracorporeal blood volume (ECV), resulting in substantial loss of platelets and red blood cells (RBCs). In this study, we developed a safe and effective modified procedure to collect peripheral blood stem cells (PBSCs) from rhesus monkeys (Macaca mulata) using a Baxter CS3000+ Blood Cell Separator (Baxter, Deerfield, IL) with several devices that reduced chamber size and shortened the standard apheresis kit to decrease ECV from 130 to 70 ml. Pump speed was controlled by monitoring hematocrit values and platelet counts during leukapheresis. This system makes it possible to perform safe and effective leukapheresis in rhesus monkeys whose body weight is similar to that of human infants. A total of 12 leukapheresis procedures were performed in nine monkeys and resulted in the collection of sufficient numbers of white blood cells (mean, 1.38 × 109 cells/kg), CD34+ cells (mean, 17.80 × 106 cells/kg), mononuclear cells (mean, 3.67 × 108 cells/kg), and colony forming units (mean, 75.02 × 106 cells/kg) in all cases. In addition, no complications, such as anemia or trombocytopenia, occurred after leukapheresis. This modified leukapheresis procedure will be useful to test new approaches in gene therapy, perform organ transplantation using nonhuman primates, and collect PBSCs from human infants in a noninvasive manner. Our nonhuman primate model provides an important framework for such future clinical studies. J. Clin. Apheresis 18:26–31, 2003. © 2003 Wiley‐Liss, Inc.
A support group for patients who have recovered from thrombotic thrombocytopenic purpura‐hemolytic uremic syndrome (TTP‐HUS): The six‐year experience of the Oklahoma TTP‐HUS Study Group
Authors: Howard Mark A. , Duvall Deanna , Terrell Deirdra R. , Christopher Anne T. , Thomas Ira , Holloway Natalie , Vesely Sara K. , George James N.
Published: October 2004

A support group for patients who have recovered from thrombotic thrombocytopenic purpura‐hemolytic uremic syndrome (TTP‐HUS), named The Oklahoma TTP‐HUS Study Group, has been a successful program for 6 years. This group has met 3 times each year with an average attendance of 16 former patients; in addition, an average of 14 family members and friends have attended each meeting. Eighty‐four percent of patients who attended a meeting were women as compared to 68% women among those who did not attend (P = 0.016). Twenty‐three percent of patients who attended a meeting have relapsed as compared to 8% among those who did not attend (P = 0.006). There was also a difference in the rates of attendance among the different clinical categories of patients (P < 0.001). A survey of former patients, as well as their families and friends, documented that interest in learning more about TTP‐HUS and talking with other people who have had TTP‐HUS were principal motivations for attending the meetings. The meetings of The Oklahoma TTP‐HUS Study Group have been successful not only for support of former patients but also for research. Long‐term patient follow‐up has been facilitated and the group discussions have revealed previously unreported persistent problems with cognitive ability and endurance. A survey of member centers of the American Association of Blood Banks and America's Blood Centers revealed no similar programs for patients who have recovered from TTP‐HUS. The absence of a support group for TTP‐HUS in the national survey contrasts to the 274 patient support groups and related wellness/education classes, including some for rare disorders, currently active in the Oklahoma City metropolitan area. The experience of The Oklahoma TTP‐HUS Study Group suggests that it serves a previously unmet need. J. Clin. Apheresis 18:16–20, 2003. © 2003 Wiley‐Liss, Inc.
Detection of Staphylococcus aureus in peripheral blood stem cell cultures after sterilization of standard blood cultures
Authors: Schwaber Mitchell J. , Krasner Carolyn N. , Gold Howard S. , Venkataraman Lata , Avigan David E. , Karchmer Adolf W. , Uhl Lynne
Published: October 2004

We report central venous catheter (CVC)‐associated Staphylococcus aureus bacteremia detected by apheresis product culture after sterilization of standard blood cultures. A 64‐year‐old man with non‐Hodgkin's lymphoma underwent peripheral blood stem cell (PBSC) collection. Five days after placement of a CVC, inflammation was evident at the insertion site. The CVC was removed and cephalexin was begun. Discharge at the site contained neutrophils and gram‐positive cocci in pairs and clusters. Cultures of the discharge, of blood drawn via the CVC, of the CVC tip and of the apheresis product collected that day grew methicillin‐susceptible S. aureus (MSSA). Cephalexin was discontinued in favor of oxacillin. Three days after removal of the CVC, PBSC collections were resumed via a contralateral CVC. Three sets of standard blood cultures drawn the day the new CVC was placed and the following day were negative, yet apheresis product cultures from each of these days grew MSSA. PBSC collections were halted, the CVC was removed, and oxacillin was continued via a peripherally inserted central catheter. Transesophageal echocardiography after two weeks of therapy revealed thickened mitral leaflets and damage to the posterior leaflet. Transthoracic echocardiography 11 weeks preceding this study had demonstrated normal mitral valve anatomy and function. Oxacillin was continued for six weeks, after which PBSC collections were resumed. Pulsed‐field gel electrophoresis of the MSSA isolates revealed a clonal pattern. Cultures of apheresis product may be more sensitive to the presence of bacteremia than standard blood cultures, and they should guide clinical decisions when the bacteria isolated are potential pathogens or suggest clinical infection. J. Clin. Apheresis 18:37–39, 2003. © 2003 Wiley‐Liss, Inc.
Plasmapheresis for severe lipemia: Comparison of serum‐lipid clearance rates for the plasma‐exchange and double‐filtration variants
Authors: Yeh Jiann‐Horng , Lee May‐Fen , Chiu Hou‐Chang
Published: October 2004

Patients with extremely high triglyceride levels and associated lipemia are at high risk for acute pancreatitis. To evaluate plasmapheresis efficacy for severe hypertriglyceridemia, 18 patients who had not responded to previous therapies were selected for either the plasma‐exchange (PE) or double‐filtration (DF) treatment variants. After treatment, the mean serum concentrations for triglyceride and cholesterol fell significantly from 1,977.1 and 436.7 mg/dl to 692.6 and 222 mg/dl, respectively. The cholesterol‐removal rate was significantly higher for the PE group (P = 0.0082), which also had a lower incidence of hemolysis during the plasmapheresis treatment (P = 0.0430). Improved clearance of serum triglyceride was strongly associated with a lower level of maximal transmembrane pressure (TMP; P = 0.0030), reduced plasmapheresis duration (P = 0.0035), and higher rates of plasma (P = 0.0255) and blood flow (P = 0.0480) during plasmapheresis. In comparison to reports in the literature, the removal rates for serum lipids were lower in our study, possibly as a consequence of early saturation of the plasma separator resulting from blockage caused by the extremely high level of triglyceride‐containing lipoproteins. Therefore, PE may be more suitable for the initial treatment of severe hypertriglyceridemia as saturation is prevented. Increasing blood and plasma flow rates, reduction of the TMP level, and reducing effective plasmapheresis duration will improve the clearance of serum lipids during treatment. J. Clin. Apheresis 18:32–36, 2003. © 2003 Wiley‐Liss, Inc.
Quality of packed red blood cells and platelet concentrates collected by multicomponent collection using the MCS plus device
Authors: Leitner G.C. , Jilma‐Stohlawetz P. , Stiegler G. , Weigel G. , Horvath M. , Tanzmann A. , Höcker P. , Fischer M.B.
Published: October 2004

The demand for blood components is constantly increasing, while the exclusion criteria for donors are strengthened in order to reach maximal safety for donors and patients. To counterbalance reduced availability of volunteers, multicomponent collections (MCC) is an attractive approach to produce more than one component during a single apheresis procedure from one donor, such as packed red blood cells (PRBCs) and platelet concentrates (PCs). Further, the exposures of patients to a limited number of donors reduces the possibility of alloimmunization and transfusion‐related diseases. We measured the quality of PRBCs and PCs obtained by MCC, using the MCS+ device with the LDPRBC program, Revision B, and compared them with the quality of manually collected PRBCs and PCs collected with the Revision C2 of the MCS+. We found higher pH levels and lower hemolysis assessed by means of fHb and K+ in the supernatant of PRBCs over the whole storage period of 42 days in MCC‐derived PRBCs. The functional metabolism assessed by intracellular ATP was higher in PRBCs collected by MCC than in manually collected units. Furthermore, PCs obtained during MCC showed an increase in p‐selectin expression on day 5 of storage compared to PCs collected with the Revision C2 of the MCS+. The p‐selectin expression on MCC platelets was within the range of p‐selectin expression found in PCs obtained by other apheresis devices. These results indicate less storage lesion in MCC‐derived PRBCs compared to manually collected units and no compromise in the quality of MCC PCs obtained in the same apheresis procedure. J. Clin. Apheresis 18:21–25, 2003. © 2003 Wiley‐Liss, Inc.
PVD‐Niedertemperaturbeschichtung für Bauteile zur Integration tribologischer Funktionen in die Oberfläche
Authors: Bobzin K. , Lugscheider E. , Maes M.
Published: October 2004

Die Realisierung neuer, komplexer Schichtsysteme und vor allem die Niedertemperaturbeschichtung für Bauteile sind mit einem enormen Prozessaufwand verbunden. Mithilfe modernster Prozesstechnik, insbesondere der Pulstechnologie, können zunehmend leistungsfähigere Werkstoffsysteme entwickelt werden, die den hohen Anforderungen in den Bauteilprüfständen standhalten. Für die Bauteilbeschichtung spielen sowohl die Temperatursenkung bis unter 160 °C als auch Reinigungsprozesse eine entscheidende Rolle. Plasmaätzprozesse müssen an die Grundwerkstoffe angepasst und optimiert werden. Des weiteren sind gute Reibeigenschaften bei Bauteilen häufig entscheidender als der Verschleißschutz.

Die Entwicklung des Schichtsystems ZrCg basiert auf der Idee, verschleißfeste und reibmindernde PVD‐Schichten (Physical Vapour Deposition) zu erzeugen, die nach einer Einlaufphase eine glatte Oberfläche mit einem nahezu stationären Verschleißzustand erreichen. Die Gradierung wird durch eine kontinuierliche Erhöhung des Reaktivgasflusses des Kohlenstoffträgergases erzeugt. An der Oberfläche der Schicht bildet sich dann eine scherweiche Lage aus Kohlenstoff und innerhalb der Schicht bildet sich beim Durchlaufen der stöchiometrischen Zusammensetzung von C und Zr die Hartstoffphase ZrC. Um eine gute Anbindung an den Grundwerkstoff zu gewährleisten, beginnt der Beschichtungsprozess mit einer weicheren, metallischen Zr‐Schicht als Haftvermittler. Die bisher entwickelten Systeme ZrCg zeigen ein hohes Potenzial für die Bauteilbeschichtung und unterschiedliche Varianten konnten an Triboprüfständen für Getriebe, Axiallager und hydraulische Verdrängereinheiten bereits erfolgreich getestet werden.

Neben Kohlenstoffschichten zeigen CrN‐Schichten ein großes Potenzial für die Bauteilbeschichtung. Zwar sind Cr‐Basis‐Schichten weicher als Ti‐Basis‐Schichten, dennoch liegen ihre Härtewerte aber deutlich über denen der niedriglegierten Stahlsubstrate, so dass eine Verbesserung des Abrasionswiderstandes erreicht wird. Ein wesentlicher Vorteil der Cr‐Basis‐Schichten ist ihr niedriges E‐Modul, durch das Cr‐Basis‐Schichten bei Wechselbelastungen im Impact‐Test deutlich höhere Standzeiten erreichen. Eine Weiterentwicklung der CrN‐Schichten stellt das System (Crx,Al1‐x)N dar, das umfangreich untersucht wurde. Neben einer sehr guten Korrosionsschutzwirkung zeichnet sich (Crx,Al1‐x)N durch einen hohen Adhäsionswiderstand aus. Durch die Zugabe von AlN zum CrN lässt sich die Härte bei gleichzeitiger Senkung des E‐Moduls, steigern.
Abrasive wear mechanisms of VPS‐ and HVOF‐sprayed TiC‐Ni based nanocrystalline coatings
Authors: Qi X. , Aust E. , Eigen N. , Gärtner F. , Bormann R.
Published: October 2004

Nanocrystalline coatings have a high potential for various engineering applications, e.g. against wear of rolls in the paper fabrication and as corrosion protection. Using vacuum plasma spray (VPS) and high velocity oxy‐fuel (HVOF) spray techniques, coating materials are exposed to high flame temperatures only for less than a millisecond. Therefore, high‐energy milled powders can be used as feedstock material without losing its nanocrystalline microstructure during the thermal spray process. In this way, homogeneous, dense nanocrystalline coatings can be produced, which show enhanced hardness, thus obtaining promising superior wear resistance. In the present study, (Ti,Mo)(C,N)‐45vol.%NiCo nanocrystalline coatings were prepared by VPS‐ and HVOF‐spraying of high‐energy milled powders. Abrasive wear tests JIS H 8615 with varying number of strokes and scratch tests with a Vickers indenter were applied to produce wear traces on the polished surfaces of the nanocrystalline coatings. Abrasive wear behaviour was analyzed by investigating the surface morphologies with optical microscopy (OM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). Experimental results indicate that the VPS‐coating has higher abrasive wear resistance than the HVOF‐coating according to the JIS H8615 test. The abrasive wear mechanism of VPS‐sprayed nanocrystalline coatings can be delineated as cutting plus ploughing. For HVOF‐sprayed nanocrystalline coatings the abrasive wear mechanism can be described as cutting plus material delamination.
Search for cerebral G cluster neurons responding to taste stimulation with seaweed in Aplysia kurodai by the use of calcium imaging
Authors: Yoshida Ryusuke , Nagahama Tatsumi
Published: October 2004

The calcium imaging method can detect the spike activities of many neurons simultaneously. In the present experiments, this method was used to search for unique neurons contributing to feeding behavior in the cerebral ganglia of Aplysia kurodai. We mainly explored the neurons whose cell bodies were located in the G cluster and the neuropile region posterior to this cluster on the ventral surface of the cerebral ganglia. When the extract of the food seaweed Ulva was applied to the tentacle‐lip region, many neurons stained with a calcium‐sensitive dye, Calcium Green‐1, showed changes in fluorescence. Some neurons showed rhythmic responses and others showed transient responses, suggesting that these neurons may be partly involved in the feeding circuits. We also identified three motor neurons among these neurons that showed rhythmic fluorescence responses to the taste stimulation. One of them was a motor neuron shortening the anterior tentacle (ATS), and the other two were motor neurons producing lip opening‐like (LOG) and closing‐like (LCG) movements, respectively. Application of the Ulva extract to the tentacle‐lip region induced phase‐locked rhythmic firing activity in these motor neurons, suggesting that these neurons may contribute to the rhythmic patterned movements of the anterior tentacles and lips during the ingestion of seaweed. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 299–314, 2003
Invertebrate D2 type dopamine receptor exhibits age‐based plasticity of expression in the mushroom bodies of the honeybee brain
Authors: Humphries Merideth A. , Mustard Julie A. , Hunter Stacey J. , Mercer Alison , Ward Vernon , Ebert Paul R.
Published: October 2004

We have isolated a cDNA clone from the honeybee brain encoding a dopamine receptor, AmDop2, which is positively coupled to adenylyl cyclase. The transmembrane domains of this receptor are 88% identical to the orthologous Drosophila D2 dopamine receptor, DmDop2, though phylogenetic analysis and sequence homology both indicate that invertebrate and vertebrate D2 receptors are quite distinct. In situ hybridization to mRNA in whole‐mount preparations of honeybee brains reveals gene expression in the mushroom bodies, a primary site of associative learning. Furthermore, two anatomically distinct cell types in the mushroom bodies exhibit differential regulation of AmDop2 expression. In all nonreproductive females (worker caste) and reproductive males (drones) the receptor gene is strongly and constitutively expressed in all mushroom body interneurons with small cell bodies. In contrast, the large cell‐bodied interneurons exhibit dramatic plasticity of AmDop2 gene expression. In newly emerged worker bees (cell‐cleaning specialists) and newly emerged drones, no AmDop2 transcript is observed in the large interneurons whereas this transcript is abundant in these cells in the oldest worker bees (resource foragers) and older drones. Differentiation of the mushroom body interneurons into two distinct classes (i.e., plastic or nonplastic with respect to AmDop2 gene expression) indicates that this receptor contributes to the differential regulation of distinct neural circuits. Moreover, the plasticity of expression observed in the large cells implicates this receptor in the behavioral maturation of the bee. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 315–330, 2003
Developmental changes in the modulation of respiratory rhythm generation by extracellular K+ in the isolated bullfrog brainstem
Authors: Winmill Rachel E. , Hedrick Michael S.
Published: October 2004

This study tested the hypothesis that voltage‐dependent, respiratory‐related activity in vitro, inferred from changes in [K+]o, changes during development in the amphibian brainstem. Respiratory‐related neural activity was recorded from cranial nerve roots in isolated brainstem–spinal cord preparations from 7 premetamorphic tadpoles and 10 adults. Changes in fictive gill/lung activity in tadpoles and buccal/lung activity in adults were examined during superfusion with artificial CSF (aCSF) with [K+]o ranging from 1 to 12 mM (4 mM control). In tadpoles, both fictive gill burst frequency (fgill) and lung burst frequency (flung) were significantly dependent upon [K+]o (r2 > 0.75; p < 0.001) from 1 to 10 mM K+, and there was a strong correlation between fgill and flung (r2 = 0.65; p < 0.001). When [K+]o was raised to 12 mM, there was a reversible abolition of fictive breathing. In adults, fictive buccal frequency (fbuccal), was significantly dependent on [K+]o (r2 = 0.47; p < 0.001), but [K+]o had no effect on flung (p > 0.2), and there was no significant correlation between fbuccal and flung. These data suggest that the neural networks driving gill and lung burst activity in tadpoles may be strongly voltage modulated. In adults, buccal activity, the proposed remnant of gill ventilation in adults, also appears to be voltage dependent, but is not correlated with lung burst activity. These results suggest that lung burst activity in amphibians may shift from a “voltage‐dependent” state to a “voltage‐independent” state during development. This is consistent with the hypothesis that the fundamental mechanisms generating respiratory rhythm in the amphibian brainstem change during development. We hypothesize that lung respiratory rhythm generation in amphibians undergoes a developmental change from a pacemaker to network‐driven process. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 278–287, 2003
The heparan sulfate proteoglycan agrin modulates neurite outgrowth mediated by FGF‐2
Authors: Jung Kim Min , Cotman Susan L. , Halfter Willi , Cole Gregory J.
Published: October 2004

Although the role of agrin in the formation of the neuromuscular junction is well established, other functions for agrin have remained elusive. The present study was undertaken to assess the role of agrin in neurite outgrowth mediated by the heparin‐binding growth factor basic fibroblast growth factor (FGF‐2), which we have shown previously to bind to agrin with high affinity and that has been shown to mediate neurite outgrowth from a number of neuronal cell types. Using both an established neuronal cell line, PC12 cells, and primary chick retina neuronal cultures, we find that agrin potentiates the ability of FGF‐2 to stimulate neurite outgrowth. In PC12 cells and retinal neurons agrin increases the efficacy of FGF‐2 stimulation of neurite outgrowth mediated by the FGF receptor, as an inhibitor of the FGF receptor abolished neurite outgrowth in the presence of agrin and FGF‐2. We also examined possible mechanisms by which agrin may modulate neurite outgrowth, analyzing ERK phosphorylation and c‐fos phosphorylation. These studies indicate that agrin augments a transient early phosphorylation of ERK in the presence of FGF‐2, and augments and sustains FGF‐2 mediated increases in c‐fos phosphorylation. These data are consistent with established mechanisms where heparan sulfate proteoglycans such as agrin may increase the affinity between FGF‐2 and the FGF receptor. In summary, our studies suggest that neural agrin contributes to the establishment of axon pathways by modulating the function of neurite promoting molecules such as FGF‐2. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 261–277, 2003
Single‐cell analysis reveals cell‐specific patterns of expression of a family of putative voltage‐gated sodium channel genes in the leech
Authors: Blackshaw Susanna E. , Henderson Leslie P. , Malek Julie , Porter Donna M. , Gross Robert H. , Angstadt James D. , Levasseur Sarah M. , Maue Robert A.
Published: October 2004

To understand the molecular basis of nervous system function in the leech, Hirudo medicinalis, we have isolated four novel cDNAs encoding putative voltage‐gated sodium (Na) channel α subunits, and have analyzed the expression of these genes in individual neurons of known function. To begin, degenerate oligonucleotide primers were used in combination with pre‐existing cDNA libraries and reverse transcriptase‐coupled polymerase chain reactions (RT‐PCR). The putative leech Na channel cDNAs (LeNas) exhibit a higher degree of sequence homology to Na channel genes in other species than to voltage‐gated calcium or potassium channel genes, including those expressed in leech. All LeNa cDNAs contain sequences corresponding to regions of functional importance in Na channel α subunits, including the “S4 region” involved in activation, the “pore loops” responsible for ion selectivity, and the “inactivation loop” between the third and fourth domains, though the latter lacks the highly conserved “IFM” motif critical for mammalian Na channel inactivation. Sequences corresponding to important determinants of tetrodotoxin sensitivity are found in some, but not all, LeNa cDNAs, consistent with prior electrophysiological evidence of Na channel heterogeneity in the leech with respect to this toxin. Subsequently, two different sets of isoform‐specific primers and methods of RT‐PCR, including a sensitive, fluorescence‐based “real time” RT‐PCR, were used to analyze LeNa isoform expression in functionally distinct neurons. The results from both approaches were consistent, and not only demonstrated that individual neurons often express more than one LeNa isoform, but also revealed cell‐specific patterns of Na channel isoform expression in the leech nervous system. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 355–371, 2003
Sex differences in rabbit masseter motoneuron firing behavior
Authors: English Arthur W. , Widmer Charles G.
Published: October 2004

To evaluate whether sex differences in the proportions of fibers of different phenotypes in the masseter muscle might be the result of differences in the behavior of their motoneurons, we studied the firing patterns of masseter motoneurons in adult male and female rabbits. Activity in individual motoneurons was determined from high spatial resolution EMG recordings made during cortically evoked rhythmic activation of the masticatory muscles. Although some motoneurons could be said to fire according to slow‐tonic or fast‐phasic patterns, most did not. In both sexes a substantial range of median firing rates and median firing durations was found. In adult males, masseter motoneurons fired more rapidly than those recorded from adult females. No significant sex differences in motoneuron firing duration were found. These results are consistent with the hypothesis that androgen‐induced differences in rabbit masseter muscle fiber phenotype are a reflection of differences in motoneuron firing rate. Whether this effect of androgen is directly upon the motoneurons or is the result of a response of muscle fibers to androgen remains to be investigated. © 2003 Wiley Periodicals, Inc. J Neurobiol 55: 331–340, 2003
Examination of Morphological Changes that Affect Gas Permeation through Thermally Damaged Explosives
Authors: Parker Gary R. , Peterson Paul D. , Asay Blaine W , Dickson Peter M. , Perry W. Lee , Henson Bryan F. , Smilowitz Laura , Oldenborg Michael R.
Published: October 2004

Photomicrography and software‐based quantitative image analysis were used to examine microstructural morphology of samples of a plastic bonded explosive, PBX 9501, which had been thermally damaged under varied confinement conditions. Samples were damaged to an advanced state, as would be attained just prior to cook‐off. We observed significant changes in morphology, when compared to pristine material, which contribute to higher gas permeability. Changes included the formation of channels and pores, as well as fracturing of the HMX crystalline component. We discuss both qualitative and quantitative observations of morphology and whether they are likely to affect sensitivity and behavior of PBX 9501.
Physicochemical Parameters of Nitramines Influencing Shock Sensitivity
Authors: van der Heijden Antoine E. D. M. , Bouma Richard H. B. , van der Steen Albert C.
Published: October 2004

TNO Prins Maurits Laboratory has actively followed and contributed to the research on the development of insensitive munitions (IM). One of the initial research topics at TNO focused on the improvement of the shape of RDX crystals and its relation to the shock sensitivity. The variation of crystal shape has been studied by crystallization from different solvents and/or by post‐treatment of the crystals. The role of the mean particle size on shock sensitivity was also included in these analyses. The decrease in shock sensitivity is even more pronounced when controlling the internal quality of crystals. In the meantime research has shifted to other energetic materials as well – in particular HMX and CL‐20 – in this way revealing step by step the important physicochemical parameters which play a role in determining the shock sensitivity of formulations containing these types of nitramines. Various characterization techniques, to determine the internal and external quality of crystals will be discussed, and their relation to shock sensitivity in PBXs will be shown. Two different grades of I‐RDX have been subjected to different characterization tests. The objective is to gain more understanding about which of the physicochemical parameters enables one to discriminate between a reduced sensitivity RDX and normal RDX.
Preheating Sensitization of a TATB Composition Part one: Chemical Evolution
Authors: Belmas Robert , Bry Alain , David Claire , Gautier Laurent , Keromnès Anne , Poullain Didier , Thevenot Gilles , Gallic Christian Le , Chenault Jacques , Guillaumet Gérald
Published: October 2004

We analyze the evolution of the sensitivity of a TATB composition after thermal cycles at elevated temperatures. Sensitization due to thermal cycles is of variable magnitude depending on the kind of the second stimulus (mechanical or thermal). In order to investigate the possible mechanisms which govern these phenomena, we perform an extensive study of the evolution of the chemistry and microstructure of our composition and we determine the sensitivity of our explosive to various stimuli after various temperature/duration cycles. This first paper is devoted to the study of TATB chemical evolutions. We present the results obtained for explosive decomposition, furazan generation, gas analyses and solid residue characterization.
A Few Remarks About the Gurney Energy of Condensed Explosives
Authors: Danel Jean‐Francois , Kazandjian Luc
Published: October 2004

After reconsidering the definition and characteristics of the Gurney energy, we explain some points related to the evaluation and practical use of this quantity. We correct a recently published relationship between the detonation velocity of an explosive and its Gurney energy at infinite expansion. Then, in the framework of cylinder tests, we indicate that the Gurney energy gives only a rough evaluation of experimental results; it can, however, be reasonably used to compare the ability of explosives to accelerate metals. Besides, the value γ=3 classically evoked for the polytropic gamma of the detonation products generally leads to significant errors in the evaluation of the Gurney energy at infinite expansion.
Deflagration of HMX‐Based Explosives at High Temperatures and Pressures
Authors: Maienschein Jon Lee , Wardell Jeffrey Francis , DeHaven Martin Raymond , Black Collin Kevin
Published: October 2004

We measure the deflagration behavior of energetic materials at extreme conditions (up to 520 K and 1 GPa) in the LLNL High Pressure Strand Burner, thereby obtaining reaction rate data for prediction of violence of thermal explosions. The apparatus provides both temporal pressure history and flame time‐of‐arrival information during deflagration, allowing direct calculation of deflagration rate as a function of pressure. Samples may be heated before testing. Here we report the deflagration behavior of several HMX‐based explosives at pressures of 10–600 MPa and temperatures of 300–460 K. We find that formulation details are very important to overall deflagration behavior. Formulations with high binder content (≥15 wt%) deflagrate smoothly over the entire pressure range regardless of particle size, with a larger particle size distribution leading to a slower reaction. The deflagration follows a power law function with the pressure exponent being unity. Formulations with lower binder content (≤10 wt% or less) show physical deconsolidation at pressures over 100–200 MPA, with transition to a rapid erratic deflagration 10–100 times faster. High temperatures have a relatively minor effect on the deflagration rate until the HMX β→δ phase transition occurs, after which the deflagration rate increases by more than a factor of 10.
Communication support system adapted to a user's background knowledge and the topic context
Authors: Sumi Kaoru , Nishida Toyoaki
Published: October 2004

This paper proposes a technique for interpolating the information in a real‐time conversation via computer between a speaker and listener to compensate for differences in the knowledge presumed for the conversation and introduces Telme, a communications support system that uses this technique. The basic premises are that the system infers the context of the current topic based on the terms used by the speaker and infers the listener's degree of knowledge from the listener's questions and a history of operations such as operations for saving certain data. It then supplements the text information of the words dictated by the speaker with information that the listener should require based on those inferences and displays it on the screen. The degree of knowledge is inferred based on the user's conceptual space, which was generated by using multiple conceptual spaces that were created based on the views and opinions of specialists in various fields. The user's conceptual space, which consists of a set of key words having interrelationships, is adapted to the user by functions for inferring those relationships and the user's degree of knowledge through the user's interactions with the computer. This paper proposes a technique, explains basic mechanisms, and reports on and examines application examples and evaluation experiments. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(7): 87–98, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10115
Quantitative examinations for human arm trajectory planning in three‐dimensional space
Authors: Yamanaka Kazuhiro , Wada Yasuhiro , Kawato Mitsuo
Published: October 2004

The following two characteristics of point‐to‐point human arm movement on a plane have been well demonstrated: (1) The path is roughly a straight line but slightly curved. (2) The velocity profile is bell shaped with a single peak. Several models have been proposed to explain these features. Four criteria for trajectory planning based on optimal principles have been proposed: the minimum hand jerk criterion, the minimum angle jerk criterion, the minimum torque change criterion, and the minimum commanded torque change criterion. It has been shown that trajectories generated by the minimum commanded torque change model correspond well with measured trajectories in a horizontal and sagittal work space. However, it was very difficult to establish a robust method for obtaining an optimal trajectory based on the minimum commanded torque change criterion, because of the need to solve a nonlinear optimization problem. Recently, Wada and colleagues proposed a new method to stably calculate optimal trajectories based on the minimum commanded torque change criterion. The method can obtain trajectories satisfying the Euler–Poisson equations with sufficiently high accuracy. We show that optimal trajectories based on the minimum commanded torque change criterion in three‐dimensional space can be calculated by applying the method. Finally, we show that the measured trajectory is closest to the minimum commanded torque change trajectory by statistical examination of many point‐to‐point trajectories in three‐dimensional space. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(7): 43–54, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.10323
Does the vestibular (otolith) system contribute to stabilizing vision during linear transient head movement?
Authors: Hikita Shinichi , Kasai Takeshi
Published: October 2004

When the head is suddenly translated, eye movement of the vestibular (otolith) system and of the visual (smooth pursuit) system possibly contribute to stabilization of vision. To investigate how these two systems work together, we compared the eye velocity while fixating on a visual target (LVORv) or a remembered target (LVORr) during head translation with that of smooth pursuit (SP). Latency of LVORv and LVORr responses proved much shorter than that of pursuit. The eye velocity of LVORv response was close to the addition of those in LVORr and SP responses until 216 ms from motion onset. These findings suggest that the neural command signal of the otolith system is linearly added to those of the pursuit system. © 2003 Wiley Periodicals, Inc. Syst Comp Jpn, 34(7): 1–9, 2003; Published online in Wiley InterScience (www.interscience. wiley.com). DOI 10.1002/scj.10400