bluuebunny/crossref_metadata_2025 huggingface dataset:
The Use of Performance Improvement Methods to Enhance Emergency Department Patient Satisfaction in the United States: A Critical Review of the Literature and Suggestions for Future Research
Authors: Boudreaux Edwin D. , Cruz Brian L. , Baumann Brigitte M.
Published: May 2006

Objectives:
The authors reviewed the evidence on performance improvement methods for increasing emergency department (ED) patient satisfaction to provide evidence‐based suggestions for clinical practice.

Methods:
Data sources consisted of searches through MEDLINE, CINAHL, PSYCHINFO, Cochrane Library, and Emergency Medicine Abstracts and a manual search of references. Articles were included if they reported a performance improvement intervention targeting patient satisfaction in the ED setting. Articles on studies not conducted in the United States or that failed to provide enough details to allow critical evaluation of the study were excluded. Two authors used structured evaluation criteria to independently review each retained study.

Results:
Nineteen articles met all selection criteria. Three studies found varying levels of support for multicomponent interventions, predominantly focused on implementation of clinical practice guidelines for specific presenting complaints and process redesign. Sixteen studies evaluated single‐component interventions, with the following having at least one supportive study: using alternating patient assignment to provider teams rather than “zone”‐based assignment, enhancing provider communication and customer service skills, incorporating information delivery interventions (e.g., pamphlets, video) that target patient expectations, using preformatted charts, and establishing ED‐based observation units for specific conditions such as asthma and chest pain.

Conclusions:
There is modest evidence supporting a range of performance improvement interventions for improving ED patient satisfaction. Further work is needed before specific, evidence‐based recommendations can be made regarding which process changes are most effective. Recommendations are made for improving the quality of performance improvement efforts in the ED setting.
Proliferative Activity of Human Thyroid Cells in Various Age Groups and Its Correlation with the Risk of Thyroid Cancer after Radiation Exposure
Authors: Saad Ali G. , Kumar Seena , Ron Elaine , Lubin Jay H. , Stanek Jerzy , Bove Kevin E. , Nikiforov Yuri E.
Published: May 2006

Context: The thyroid gland is vulnerable to the carcinogenic effects of ionizing radiation, and there is a well-documented inverse correlation between thyroid cancer and age at exposure, particularly for ages less than 20 yr. One of the factors responsible for this phenomenon may be more rapid cell proliferation in children.

Objective: The objective of this study was to determine the proliferative rate of normal human thyroid cells in different age groups.

Design: We used immunohistochemical analysis to determine the Ki-67 proliferative index in 117 thyroid glands obtained at autopsy, including 25 fetal thyroids (11–40 wk gestation), 55 childhood thyroids (0–19 yr), and 37 adult thyroids (20–60 yr).

Results: The rate of Ki-67 labeling in the three groups was 7.4 ± 6.10, 0.23 ± 0.15, and 0.08 ± 0.04% respectively, demonstrating an overall trend for diminishing proliferative activity of thyroid cells with increasing age. However, a lack of correlation was noted between the slopes of cancer risk calculated from previous studies of irradiated populations and proliferative rate in the pediatric age intervals of 0–4 and 5–9 yr, suggesting that other factors are likely to be responsible for the particularly high sensitivity to radiation-induced thyroid cancer among the youngest children.

Conclusions: Our findings of a general decrease in proliferative activity of thyroid cells with age may explain, at least in part, the higher risks of radiation-related thyroid cancer in children compared with adults. However, the variation in the rate of cell proliferation is unlikely to be responsible entirely for this phenomenon and other factors may also be involved.
Preparation of New Liquid Crystals with a Benzoyloxytropone Core
Authors: Mori Akira , Uchida Minoru , Takeshita Hitoshi
Published: May 2006

Compounds having liquid crystal properties with a tropolone core were synthesized: A series of 5-alkoxy-2-benzoyloxytropones showed the mesophase(s), whereas corresponding 5-alkoxy-2-benzyloxytropones did not. A [1,9] sigmatropy seems to play an important role to this mesomorphic behavior.
Effect of Proline in Basic and α-Helical Amphipathic Peptides on Acidic Liposomes and Their Antimicrobial Activity
Authors: Lee Sannamu , Park Nam Gyu , Kato Tamaki , Aoyagi Haruhiko , Kato Tetsuo
Published: May 2006

A helix-breaker amino acid, proline, was introduced into an antimicrobial peptide, Ac–(L–Leu–L–Ala–L–Arg–L–Leu)3–NHCH3 (43). The peptides [Pro6]43 (1), [Pro2,6]43 (2), and [Pro2,6,10]43 (3) were able to form α-helix in order of 1 > 2 > 3 in the presence of acidic liposomes, indicating that proline does not always behave as a strong helix-breaker in specific surroundings. The antimicrobial activity was found to be connected closely with their amphipathic property.
Chiral Environment around the Metal Center Observed by the Epoxidation with the Iron Complexes of Bleomycin and the Synthetic Analogue
Authors: Kaku Yumiko , Otsuka Masami , Ohno Masaji
Published: May 2006

cis-β-Methylstyrene is oxidized either with the Fe(III)–H2O2 or with the Fe(II)–O2 complex systems of bleomycin and the synthetic model ligand PYML-6 to give optically active epoxide, showing that the environment around the iron-nucleus is chiral enough to cause asymmetric epoxidation.
Magnesium Bromide Mediated Selective Conversion of Acetals into Thioacetals
Authors: Park Jung Ho , Kim Sunggak
Published: May 2006

Magnesium bromide in ether is found to be a very effective and highly selective reagent for the conversion of acetals into the corresponding thioacetals in the presence of ketones.
Solid Phase Synthesis of Magainin 1 under Continuous Flow Conditions
Authors: Nozaki Sukekatsu
Published: May 2006

4-(Hydroxymethyl)phenoxymethyl copoly(styrene-1% divinylbenzene) resin beads loosely packed in a glass column was satisfactorily employed as a solid support for synthesis of magainin 1 under Fmocstrategy. The trieicosapeptide was synthesized in continuously flowing DMF under low pressure conditions. The antibiotic was obtained in an overall yield of 31% after HPLC purification.
Electricity Generation from Existing Multipurpose Dams in Turkey
Authors: Bakiş Recep
Published: May 2006

The aim of this article is to investigate the hydropower potential of multipurpose dams constructed with the purpose of supplying irrigation, domestic water supply, flood control, navigation, recreation, sanitation, and wildlife conservation but not for electricity generation in Turkey. One of the functions of multipurpose dams is to produce electricity when released water from the reservoir. More than 1175 dams in various sizes and types have been constructed so far in Turkey and according to the International Commission on Large Dams (ICOLD) definition, 555 dams have already been in operation by 2005. At the present research, out of 1175 dams, 78 multipurpose dams with an installed capacity less than 20 MW still in operation can be rehabilitated as small hydropower facilities. For this purpose, existing 78 of multipurpose dams which do not generate electricity so far have been investigated. By using these existing multipurpose dams, only minor new civil works and ready-to-use turbine generator are required, which reduces the cost of electricity generation. It has been calculated that the electricity generation using this potential is 1090.89 GWh/yr with 287.83 MW installed capacity. This potential will add an important monetary value to Turkish economy.
Performance Analysis of an Active Noise Cancellation Hearing Protector
Authors: Oinonen Mika , Raittinen Harri , Kivikoski Markku
Published: May 2006

When designing an active noise cancellation hearing protector, it is relatively easy to implement a laboratory prototype with high performance. However, when the device is taken out of the laboratory into real extremely noisy situations, it must be capable of producing very high sound pressure levels. In this paper, the factors, which limit the low frequency performance and dynamic range are analysed. The results show that the voltage swing of the loudspeaker amplifier and the force factor of the loudspeaker are two important limiting factors in extremely loud situations. A prototype of an active noise cancellation hearing protector was implemented and its performance was measured in an authentic noisy situation. The developed device attenuated 125 Hz tonal noise by 18 dB. The active noise cancellation system attenuated noise even at a sound pressure level of 118 dB SPL. This can be considered sufficient for most situations.
A New Quasi-Linearization Finite Difference Scheme for Large Deflection Analysis of Prismatic and Non-Prismatic Inextensible Slender Beams
Authors: Al-Sadder Samir Z. , Othman Raid A.
Published: May 2006

A new scheme called quasi-linearization finite differences is developed for large deflection analysis of prismatic and non-prismatic inextensible slender beams with different boundary conditions subjected to various types of continuous and discontinuous external loads in horizontal and vertical global directions.

Simultaneous equations of highly nonlinear and linear terms are obtained when casting the derived exact highly nonlinear governing differential equation using central finite differences on the nodes along the beam.

A quasi-linearization scheme is used to solve these equations based on successive corrections of the nonlinear terms in the simultaneous equations. The nonlinear terms in the simultaneous equations are assumed constant during each correction (iteration). Several representative numerical examples of prismatic and non-prismatic slender beams with different loading and boundary conditions are analyzed to illustrate the merits of the new adopted numerical scheme as well as its validity, accuracy and efficiency.

The results of the present scheme are checked using large displacement finite element analysis of MSC/NASTRAN program. A comparison between present scheme and MSC/NASTRAN results reveals excellent agreements. The advantage of the new scheme is that the load can be applied in one step with few iterations (3 to 6 iterations).
Natural Health Products in the Prevention and Treatment of Osteoporosis: Systematic Review of Randomized Controlled Trials
Authors: Whelan Anne Marie , Jurgens Tannis M , Bowles Susan K
Published: May 2006

Background:

Consumers are increasingly looking to natural health products to manage specific diseases such as osteoporosis. As a result, healthcare providers need evidence-based information on which to base recommendations regarding use and efficacy.

Objective:

To identify natural health products (NHPs, ie, dietary supplements) advocated for the prevention and treatment of osteoporosis and systematically review the evidence from randomized controlled trials for the effect of NHPs on bone mineral density (BMD)/fracture rate in women.

Methods:

MEDLINE, Natural Medicines Comprehensive Database, and the Internet were initially searched to identify NHPs advocated for prevention and treatment of osteoporosis. For NHPs having evidence to support their claim, the aforementioned sources, along with International Pharmaceutical Abstracts, the Cochrane Library, the International Bibliographic Information on Dietary Supplements, the Cumulative Index to Nursing & Allied Health, and HerbMed, were searched to locate randomized controlled trials published in English between 1966 and October 2004. Bibliographies of identified articles were also searched. Randomized controlled trials were selected if they evaluated the use of a single NHP in women, using BMD/fracture rate as the outcome measure. NHPs were excluded from further evaluation if a review had already been published. Data were extracted using predetermined criteria and studies appraised using the Jadad scale. Forty-five NHPs were identified that the authors claimed to be beneficial in prevention and treatment of osteoporosis, with 15 having evidence to support their claim. Calcium; copper; evening primrose oil; fish oils; fluoride; magnesium; manganese; strontium; vitamin D; and black, green, and oolong tea did not meet study criteria.

Results:

Results from randomized controlled trials evaluating dehydroepiandrosterone (DHEA), phytoestrogens, and vitamin K2 (menaquinone or menatetrenone) were promising; however, study limitations suggest the need for confirmatory evidence.

Conclusions:

Although no definitive conclusions can be drawn, the relative safety of phytoestrogens, DHEA, and vitamin K2 at the studied doses, as well as preliminary positive results from randomized controlled trials, provides some initial support for the use of these NHPs in the prevention and treatment of osteoporosis in women.
Comparison of the Achilles Express Ultrasonometer with Central Dual-Energy X-Ray Absorptiometry
Authors: Grabe Darren W , Cerulli Jennifer , Stroup Jeffrey S , Kane Michael P
Published: May 2006

Background:

Quantitative ultrasound (QUS) devices provide portable, easy-to-operate, low-cost options for point-of-care screening of bone mineral density (BMD). Community pharmacists should be aware of the precision, sensitivity, and specificity of these devices prior to their purchase.

Objective:

To determine the precision, sensitivity, and specificity of the Achilles Express ultrasonometer compared with central dual-energy X-ray absorptiometry (cDXA) as well as its utility as a bone density screening device in the community pharmacy setting.

Methods:

A prospective study in a community pharmacy and outpatient ambulatory clinic was conducted with 2 groups of white women. Group 1 participants were 25–35 years of age (young, healthy), and those in Group 2 were 45 years of age or older (postmenopausal). BMD assessments of the spine and the nondominant wrist and hip were performed using cDXA. Assessments of the heel were performed using the Achilles Express, a QUS device. The main outcome measures were correlation of t-scores between cDXA and QUS measurements using the Pearson correlation test.

Results:

Twenty-two (30 ± 4 years of age) and 31 (55 ± 17 years of age) women were enrolled into Groups 1 and 2, respectively. Significant correlations between QUS and hip and spine cDXA t-scores were found in both groups. Correlation coefficients for QUS versus hip cDXA were 0.51 (95% CI 0.11 to 0.77) and 0.70 (95% CI 0.46 to 0.85) in Groups 1 and 2, respectively. Correlation coefficients for the QUS versus spine cDXA were 0.64 (95% CI 0.31 to 0.84) and 0.60 (95% CI 0.31 to 0.79) in Groups 1 and 2, respectively. The QUS device has a sensitivity level of 88% and specificity of 71% to detect a hip cDXA t-score of less than –1.

Conclusions:

The Achilles Express ultrasonometer is a reasonable screening tool to detect low BMD in postmenopausal women.
Renal Tubular-cell Neoplasms in Black-footed Ferrets (Mustela nigripes)-38 Cases
Authors: Lair S. , Barker I. K. , Mehren K. G. , Williams E. S.
Published: May 2006

Thirty-eight cases of renal tubular cell neoplasms were diagnosed in 184 captive, adult (> 1-year-old), black-footed ferrets ( Mustela nigripes) examined from 1985 to 1996. This prevalence (20.7%) is one of the highest reported for this neoplasm in a population of animals. These tumors rarely metastasized (1/38), and usually were incidental postmortem findings, associated clinical disease being present in only 3 (8%) of the 38 cases. The prevalence of renal tubular cell neoplasms found at postmortem examination increased linearly with age, up to 67% in ferrets >8 years old. Both males (prevalence = 19%) and females (prevalence = 24%) were affected. Multiple renal tumors were common, and seven ferrets (18.4% of affected animals) had bilateral tumors. The cause of this neoplastic syndrome could not be determined. Since most of the animals affected by this condition were in their postreproductive years of life, the impact of this neoplastic syndrome on the captive propagation of this species is negligible.
The 2000 Canine Distemper Epidemic in Caspian Seals (Phoca caspica): Pathology and Analysis of Contributory Factors
Authors: Kuiken T. , Kennedy S. , Barrett T. , Van de Bildt M. W. G. , Borgsteede F. H. , Brew S. D. , Codd G. A. , Duck C. , Deaville R. , Eybatov T. , Forsyth M. A. , Foster G. , Jepson P. D. , Kydyrmanov A. , Mitrofanov I. , Ward C. J. , Wilson S. , Osterhaus A. D. M. E.
Published: May 2006

More than 10,000 Caspian seals ( Phoca caspica) were reported dead in the Caspian Sea during spring and summer 2000. We performed necropsies and extensive laboratory analyses on 18 seals, as well as examination of the pattern of strandings and variation in weather in recent years, to identify the cause of mortality and potential contributory factors. The monthly stranding rate in 2000 was up to 2.8 times the historic mean. It was preceded by an unusually mild winter, as observed before in mass mortality events of pinnipeds. The primary diagnosis in 11 of 13 seals was canine distemper, characterized by broncho-interstitial pneumonia, lymphocytic necrosis and depletion in lymphoid organs, and the presence of typical intracytoplasmic inclusion bodies in multiple epithelia. Canine distemper virus infection was confirmed by phylogenetic analysis of reverse transcriptase-polymerase chain reaction products. Organochlorine and zinc concentrations in tissues of seals with canine distemper were comparable to those of Caspian seals in previous years. Concurrent bacterial infections that may have contributed to the mortality of the seals included Bordetella bronchiseptica (4/8 seals), Streptococcus phocae (3/8), Salmonella dublin (1/8), and S. choleraesuis (1/8). A newly identified bacterium, Corynebacterium caspium, was associated with balanoposthitis in one seal. Several infectious and parasitic organisms, including poxvirus, Atopobacter phocae, Eimeria- and Sarcocystis-like organisms, and Halarachne sp. were identified in Caspian seals for the first time.
Renal Adenocarcinoma in a Ferret
Authors: Kawaguchi H. , Miyoshi N. , Souda M. , Maeda H. , Kawashima H. , Gejima K. , Uchida K. , Umekita Y. , Yoshida H.
Published: May 2006

A spontaneous case of renal tumor was observed in a 7-year-old ovariectomized female pet ferret ( Mustela putorius furo). Clinical signs included exhaustion, emaciation, anorexia, and stooping position. At necropsy, a solid and cystic mass replaced the left kidney and adrenal gland. The tumor was composed of pleomorphic epithelial cells with a large number of giant cells. Metastases were recognized in the lung, liver, greater omentum, right renal pelvis, and systemic lymph nodes. immunohistochemical stains revealed that the tumor cells were positive for CD10, cytokeratin (CAM 5.2), and Ki-67 (MIB-1). on the basis of morphologic and immunohistochemical features, the tumor was diagnosed as a pleomorphic renal adenocarcinoma. This type of neoplasm is very rare in all species and has never been reported in a ferret.
Gastric Adenocarcinoma and Chronic Gastritis in Two Related Persian Cats
Authors: Dennis M. M. , Bennett N. , Ehrhart E. J.
Published: May 2006

Two 12.5-year-old castrated male Persian cats from the same household, whose dams were littermates, presented simultaneously with gastric adenocarcinoma associated with proliferative and fibrosing gastritis. Intralesional adult Ollulanus tricuspis nematodes and rare surface-associated spiral-shaped bacteria were identified in one cat. No etiologic agents were identified in tissues from the second cat; however, gastric mucosa was examined following anthelmintic treatment. Clinical signs in each cat had commenced 2 months apart and included vomiting, hematemesis, intermittent melena, and weight loss. This is the first report of gastric adenocarcinoma occurring in housemate cats or cats of common descent. Carcinogenesis may have been influenced by shared undetermined genetic and environmental factors, possibly including Ollulanus tricuspis, spiral-shaped bacteria, or other etiologies for chronic gastritis that remain unidentified.
Immunophenotypic Characterization of Peripheral Blast Cells in a Leukemic Miniature Pig
Authors: Sipos W. , Gerner W. , Schilcher F. , Leeb C. , Groiss S. , Miller I. , Saalmüller A. , Schmoll F. , Schwendenwein I.
Published: May 2006

The health status of a 4-year-old female, dd-haplotype miniature pig deteriorated rapidly, so the animal finally had to be euthanized because of poor clinical condition. Necropsy revealed a massive leukocytic infiltration in the parenchymatous organs of the abdominal cavity. on hematologic cell counting, severe leukocytosis (69.3 X 109 cells/liter) and high-grade basophilia (6.9 X 109 cells/liter) were evident. cytologic examination, as well as analysis of expression of leukocyte differentiation antigens by means of flow cytometry, classified blasts, which accounted for about 22% of leukocytes, as biphenotypic cells co-expressing the myeloid marker SWC3 (CD172a) and the lymphoid markers CD5 and CD25. Hematologic features resembled those seen in humans with chronic myeloid leukemia at blast phase.
Canine Cardiac Mesothelioma with Granular Cell Morphology
Authors: Brower A. , Herold L. V. , Kirby B. M.
Published: May 2006

Cardiac mesothelioma with granular cell features was diagnosed in a 10-year-old Golden Retriever presenting with pericardial and abdominal effusions. The diagnosis was based on gross, morphologic, and immunohistochemical features. The immunohistochemical profile of the neoplasm was pancytokeratin positive, vimentin positive, and S-100 negative; most gross and morphologic features were consistent with both mesothelioma and granular cell tumor. To the authors' knowledge, the prognosis for either primary cardiac mesothelioma or granular cell tumor in the dog is unknown. At 4 months after thoracotomy, pericardectomy, and mass excision, this dog was alive and without clinical evidence of pericardial or abdominal effusions. We describe a granular morphologic variant of cardiac mesothelioma in a dog.
Systemic Granulomatous Disease and Sialometaplasia in a Dog with Bartonella Infection
Authors: Saunders G. K. , Monroe W. E.
Published: May 2006

Systemic granulomatous disease involving the spleen, heart, lymph nodes, omentum, liver, kidney, lung, mediastinum, and salivary glands developed in an 8-year-old Rottweiler. The dog also had sialometaplasia of both submandibular salivary glands. Bartonella henselae and B. vinsonii subsp. berkhoffii DNA was amplified from the salivary gland by polymerase chain reaction analysis. Bartonellae may be the cause of this systemic disease, but to the authors' knowledge, involvement of omentum, mediastinum, and salivary glands has not previously been reported in association with Bartonella infection. Bartonellae should be considered potential causes of sialometaplasia.
A characterization of two classes of locally truncated diagram geometries
Authors: Onofrei Silvia
Published: May 2006

Let Г = (P, ℒ) be a parapolar space which is locally A

n

−1, 3(IK) for some integer n > 6 and IK a field. There exists a class ID of 2-convex subspaces, each isomorphic to D
5, 5(IK), such that every symplecton of Г is contained in a unique element of ID. Let Г = (P, ℒ) be a parapolar space which is locally A

n

−1, 4(IK) for n = 7 or an integer n ≥ 9 and some field IK. Assume that Г satisfies the extra condition called the Weak Hexagon Axiom. Then there exists a class D of 2-convex subspaces, each isomorphic to D
6, 6(IK), such that every symplecton of Г is contained in a unique element of D. In both of the above cases Г is the homomorphic image of a truncated building.
Non-existence of 6-dimensional pseudomanifolds with complementarity
Authors: Bagchi Bhaskar , Datta Basudeb
Published: May 2006

In a previous paper ([10]) the second author showed that if M is a pseudomanifold with complementarity other than the 6-vertex real projective plane and the 9-vertex complex projective plane, then M must have dimension ≥ 6, and—in case of equality—M must have exactly 12 vertices. In this paper we prove that such a 6-dimensional pseudomanifold does not exist. On the way to proving our main result we also prove that all combinatorial triangulations of the 4-sphere with at most 10 vertices are combinatorial 4-spheres.
Localization of Diacylglycerol Lipase-α around Postsynaptic Spine Suggests Close Proximity between Production Site of an Endocannabinoid, 2-Arachidonoyl-glycerol, and Presynaptic Cannabinoid CB1 Receptor
Authors: Yoshida Takayuki , Fukaya Masahiro , Uchigashima Motokazu , Miura Eriko , Kamiya Haruyuki , Kano Masanobu , Watanabe Masahiko
Published: May 2006

2-Arachidonoyl-glycerol (2-AG) is an endocannabinoid that is released from postsynaptic neurons, acts retrogradely on presynaptic cannabinoid receptor CB1, and induces short- and long-term suppression of transmitter release. To understand the mechanisms of the 2-AG-mediated retrograde modulation, we investigated subcellular localization of a major 2-AG biosynthetic enzyme, diacylglycerol lipase-α (DAGLα), by using immunofluorescence and immunoelectron microscopy in the mouse brain. In the cerebellum, DAGLα was predominantly expressed in Purkinje cells. DAGLα was detected on the dendritic surface and occasionally on the somatic surface, with a distal-to-proximal gradient from spiny branchlets toward somata. DAGLα was highly concentrated at the base of spine neck and also accumulated with much lower density on somatodendritic membrane around the spine neck. However, DAGLα was excluded from the main body of spine neck and head. In hippocampal pyramidal cells, DAGLα was also accumulated in spines. In contrast to the distribution in Purkinje cells, DAGLα was distributed in the spine head, neck, or both, whereas somatodendritic membrane was labeled very weakly. These results indicate that DAGLα is essentially targeted to postsynaptic spines in cerebellar and hippocampal neurons, but its fine distribution within and around spines is differently regulated between the two neurons. The preferential spine targeting should enable efficient 2-AG production on excitatory synaptic activity and its swift retrograde modulation onto nearby presynaptic terminals expressing CB1. Furthermore, different fine localization within and around spines suggests that the distance between postsynaptic 2-AG production site and presynaptic CB1 is differentially controlled depending on neuron types.
Involvement of Basal Protein Kinase C and Extracellular Signal-Regulated Kinase 1/2 Activities in Constitutive Internalization of AMPA Receptors in Cerebellar Purkinje Cells
Authors: Tatsukawa Tetsuya , Chimura Takahiko , Miyakawa Hiroyoshi , Yamaguchi Kazuhiko
Published: May 2006

AMPA receptor (AMPAR) internalization provides a mechanism for long-term depression (LTD) in both hippocampal pyramidal neurons and cerebellar Purkinje cells (PCs). Cerebellar LTD at the parallel fiber (PF)–PC synapse is the underlying basis of motor learning and requires AMPAR activation, a large Ca2+influx, and protein kinase C (PKC) activation. However, whether these requirements affect the constitutive AMPAR internalization in PF–PC synapses remains unclarified. Tetanus toxin (TeTx) infusion into PCs decreased PF-EPSC amplitude to 60% within 20–30 min (TeTx rundown), without change in paired-pulse facilitation ratio or receptor kinetics. Immunocytochemically measured glutamate receptor 2 (GluR2) internalization ratio decreased at the steady state of TeTx rundown. TeTx rundown did not require AMPAR activity nor an increase in intracellular Ca2+concentration. TeTx rundown was suppressed partially by the inhibition of either conventional PKC or mitogen-activated protein kinase kinase (MEK) and completely by the inhibition of both kinases. The background PKC activity was shown to be sufficient, because a PKC activator did not facilitate TeTx rundown. The inhibition of protein phosphatase 1/2A (PP1/2A) enhanced TeTx rundown slightly, and both inhibition of PP1/2A and activation of PKC maximized it, but one-half of AMPARs at PF–PC synapses remained in the TeTx-resistant pool. The inhibition of actin depolymerization suppressed TeTx rundown and decreased the GluR2 internalization ratio. In contrast, the inhibition of actin polymerization enhanced TeTx rundown and increased the GluR2 internalization ratio. We suggest that the regulation of actin polymerization is involved in the surface expression of AMPARs and the surface expressing AMPARs are constitutively internalized through both basal PKC and MEK–ERK1/2 (extracellular signal-regulated kinase 1/2) activities at PF–PC synapses.
Perceptual Learning Directs Auditory Cortical Map Reorganization through Top-Down Influences
Authors: Polley Daniel B. , Steinberg Elizabeth E. , Merzenich Michael M.
Published: May 2006

The primary sensory cortex is positioned at a confluence of bottom-up dedicated sensory inputs and top-down inputs related to higher-order sensory features, attentional state, and behavioral reinforcement. We tested whether topographic map plasticity in the adult primary auditory cortex and a secondary auditory area, the suprarhinal auditory field, was controlled by the statistics of bottom-up sensory inputs or by top-down task-dependent influences. Rats were trained to attend to independent parameters, either frequency or intensity, within an identical set of auditory stimuli, allowing us to vary task demands while holding the bottom-up sensory inputs constant. We observed a clear double-dissociation in map plasticity in both cortical fields. Rats trained to attend to frequency cues exhibited an expanded representation of the target frequency range within the tonotopic map but no change in sound intensity encoding compared with controls. Rats trained to attend to intensity cues expressed an increased proportion of nonmonotonic intensity response profiles preferentially tuned to the target intensity range but no change in tonotopic map organization relative to controls. The degree of topographic map plasticity within the task-relevant stimulus dimension was correlated with the degree of perceptual learning for rats in both tasks. These data suggest that enduring receptive field plasticity in the adult auditory cortex may be shaped by task-specific top-down inputs that interact with bottom-up sensory inputs and reinforcement-based neuromodulator release. Top-down inputs might confer the selectivity necessary to modify a single feature representation without affecting other spatially organized feature representations embedded within the same neural circuitry.
Synchronization between Background Activity and Visually Evoked Potential Is Not Mirrored by Focal Hyperoxygenation: Implications for the Interpretation of Vascular Brain Imaging
Authors: Koch Stefan P. , Steinbrink Jens , Villringer Arno , Obrig Hellmuth
Published: May 2006

We performed an electroencephalography and optical topography study simultaneously exploring electrophysiological and vascular response magnitude as a function of stimulus frequency. To elicit a response in the visual cortex, subjects were exposed to flicker frequencies varying from 1 to 25 Hz (1 Hz steps, eyes closed). Extending the standard view to compare magnitudes of the evoked neuronal to the evoked vascular response, we additionally investigated modulations of α-power, a marker of “background” EEG activity.

The results show two discrepancies between the electrophysiological and vascular response: (1) VEP and α-power exhibit a discontinuous peak when stimulating at the individual α-frequency (IAF) (∼10–11 Hz), indicating resonance between background oscillations and evoked response; this is not mirrored by the vascular response. (2) The vascular response, in contrast, steadily increases up to a maximum at 7–8 Hz and slightly decreases with higher frequencies. This continuous frequency dependence is partly reflected by the decrease in α-power up to frequencies of 8–9 Hz and a slight increase in α-power beyond the IAF resonance. Although indicating an inverse relationship between α-power and vascular response, the frequency dependence of the evoked response does not show such a correlation.

Thus, electrophysiological resonance between an individual's α-frequency and isofrequent stimulation is not mirrored by the vascular response. Also, spontaneous background EEG activity is an important modulator of the vascular response magnitude. We discuss these deviations from a simple one-to-one translation between evoked potential and vascular response amplitude in the light of questions concerning synchronization, attenuation, and induction of background oscillations such as the α-rhythm.
Plasticity of Temporal Pattern Codes for Vocalization Stimuli in Primary Auditory Cortex
Authors: Schnupp Jan W. H. , Hall Thomas M. , Kokelaar Rory F. , Ahmed Bashir
Published: May 2006

It has been suggested that “call-selective” neurons may play an important role in the encoding of vocalizations in primary auditory cortex (A1). For example, marmoset A1 neurons often respond more vigorously to natural than to time-reversed twitter calls, although the spectral energy distribution in the natural and time-reversed signals is the same. Neurons recorded in cat A1, in contrast, showed no such selectivity for natural marmoset calls. To investigate whether call selectivity in A1 can arise purely as a result of auditory experience, we recorded responses to marmoset calls in A1 of naive ferrets, as well as in ferrets that had been trained to recognize these natural marmoset calls. We found that training did not induce call selectivity for the trained vocalizations in A1. However, although ferret A1 neurons were not call selective, they efficiently represented the vocalizations through temporal pattern codes, and trained animals recognized marmoset twitters with a high degree of accuracy. These temporal patterns needed to be analyzed at timescales of 10–50 ms to ensure efficient decoding. Training led to a substantial increase in the amount of information transmitted by these temporal discharge patterns, but the fundamental nature of the temporal pattern code remained unaltered. These results emphasize the importance of temporal discharge patterns and cast doubt on the functional significance of call-selective neurons in the processing of animal communication sounds at the level of A1.
A Hot-Sensing Cold Receptor: C-Terminal Domain Determines Thermosensation in Transient Receptor Potential Channels
Authors: Brauchi Sebastian , Orta Gerardo , Salazar Marcelo , Rosenmann Eduardo , Latorre Ramon
Published: May 2006

Temperature transduction in mammals is possible because of the presence of a set of temperature-dependent transient receptor potential (TRP) channels in dorsal root ganglia neurons and skin cells. Six thermo-TRP channels, all characterized by their unusually high temperature sensitivity (Q10> 10), have been cloned: TRPV1–4 are heat activated, whereas TRPM8 and TRPA1 are activated by cold. Because of the lack of structural information, the molecular basis for regulation by temperature remains unknown. In this study, we assessed the role of the C-terminal domain of thermo-TRPs and its involvement in thermal activation by using chimeras between the heat receptor TRPV1 and the cold receptor TRPM8, in which the entire C-terminal domain was switched. Here, we demonstrate that the C-terminal domain is modular and confers the channel phenotype regarding temperature sensitivity, channel gating kinetics, and PIP2(phosphatidylinositol-4,5-bisphophate) modulation. Thus, thermo-TRP channels contain an interchangeable specific region, different from the voltage sensor, which allows them to sense temperature stimuli.
Regulatory roles for mitochondria in the peri-implantation mouse blastocyst: possible origins and developmental significance of differential ΔΨm
Authors: Van Blerkom Jonathan , Cox Heather , Davis Patrick
Published: May 2006

Studies of mitochondria in mouse and human oocytes and preimplantation stage embryos have focused primarily on their metabolic capacity to generate ATP. However, it is becoming increasingly apparent that mitochondria are also regulatory agents in other processes involved in the establishment of developmental competence, including calcium homeostasis and apoptosis. The magnitude of the inner mitochondrial membrane potential, or its polarity (ΔΨm), is a physiochemical property of mitochondria related to levels of organelle activity, and differences in the magnitude and spatial distribution of high- and low-polarized mitochondria have been suggested to influence oocyte and early embryo competence. Here, we investigated mitochondrial polarity in normal and diapausing peri-implantation-stage mouse blastocysts, and their corresponding outgrowths, for indications of cell-type-specific regulatory functions or activities in which these organelles may be engaged. The results demonstrate that cell-type- and location-specific domains of differential ΔΨm exist in the peri-implantation blastocyst and remain unchanged during blastocyst outgrowth and during delayed implantation, which for the latter, is accompanied by the suppression of mitochondrial oxidative phosphorylation. Our findings demonstrate that cell-type-specific ΔΨm in the peri-implantation blastocyst is not an intrinsic property of the corresponding mitochondria but one that can be mediated by the dynamics of intercellular contact. Cells with high- or low-polarized mitochondria are differentially affected by photosensitization, with developmental consequences related to embryo behavior and outgrowth performance. Differences in polarity are discussed with respect to the participation of mitochondria in regulatory and morphogenetic processes in the normal peri-implantation embryo. The persistence of high ΔΨm in the diapausing embryo is suggested to be associated with the regulation of levels of cytoplasmic free calcium and the ability of the embryo to reactivate development when delayed implantation terminates.
Glucose utilization and the PI3-K pathway: mechanisms for cell survival in preimplantation embryos
Authors: Riley Joan K , Moley Kelle H
Published: May 2006

The maintenance of optimal glucose utilization during the preimplantation period is critical for embryo survival. A decrease in glucose transport during preimplantation development has been linked to the early steps of programmed cell death in these embryos. Decreased glucose transport is not thought to be simply a consequence of cell death, rather it is thought to be a trigger that can initiate the apoptotic cascade. Extensive apoptosis during the preimplantation period may manifest later in pregnancy as a malformation – or miscarriage, if cell loss is excessive. Phosphatidylinositol 3-kinase (PI3-K) is a known regulator of a number of physiologic responses including cellular proliferation, growth, and survival as well as glucose metabolism. Studies performed in other cell systems have demonstrated that the PI3-K pathway plays a critical role in maintaining glucose transport and metabolism. This review will present the current evidence that suggests that PI3-K is vital for preimplantation embryo survival and development. In addition, data demonstrating that PI3-K activity is important for glucose metabolism during this early developmental period will be discussed.
Effect of glycerol and cholesterol-loaded cyclodextrin on freezing-induced water loss in bovine spermatozoa
Authors: Li G , Saenz J , Godke R A , Devireddy R V
Published: May 2006

Recent experimental data show that incubating bovine sperm with cholesterol-loaded cyclodextrin (CLC) before cryopreservation increases the percentages of motile and viable cells recovered after freezing and thawing, compared with control sperm. In the present study, we report the effect of incubating bovine sperm with CLC on the subzero water transport response and the membrane permeability parameters (reference membrane permeability (Lpg) and activation energy (ELp)). Water transport data during freezing of bovine sperm cell suspensions were obtained at a cooling rate of 20 °C/min under three different conditions: 1. in the absence of cryoprotective agents (CPAs); 2. in the presence of 0.7 M glycerol; and 3. in the presence of 1.5 mg/ml CLC and 0.7 M glycerol. With previously published values, the bovine sperm cell was modeled as a cylinder of length 39.8 μm and radius 0.4 μm, with osmotically inactive cell volume (Vb) of 0.61 Vo, where Vo is the isotonic cell volume. By fitting a model of water transport to the experimentally obtained data, the best-fit water transport parameters (Lpg and ELp) were determined. The predicted best-fit permeability parameters ranged from Lpg = 0.02 to 0.036 μm/min-atm and ELp = 26.4 to 42.1 kcal/mol. These subzero water transport parameters are significantly different from the suprazero membrane permeability values (obtained in the absence of extracellular ice) reported in the literature. Calculations made of the theoretical response of bovine spermatozoa at subzero temperatures suggest that the optimal cooling rate to cryopreserve bovine spermatozoa is 45–60 °C/min, agreeing quite closely with experimentally determined rates of freezing bovine spermatozoa.
Towards an Artificial Phonological Loop: An Assistive Device for Working Memory and Attentional Control
Authors: Bogen D.
Published: May 2006

We describe the initial development of an artificial phonological loop (APL), a new technology to assist individuals with impairment of the working memory system. The phonological loop, along with the visuospatial sketchpad, is one of the two slave short‐term memory subsystems that comprise working memory, a cognitive function closely associated with the control of attention. In the phonological loop, phonological (speech) information lasting for 1–2 second is maintained active by repetitive, subvocal (silent speech) rehearsal. Deficits in working memory, specifically in the phonological loop, occur in many disorders, including attention‐deficit disorder and Alzheimer’s disease. In these disorders, it appears that the ability for phonological rehearsal is intact, but the regulation or triggering of the rehearsal process is inadequate, thus causing the contents of working memory to be lost. The purpose, then, of the APL is to facilitate the phonological loop by artificially extending the duration of phonological rehearsals. The APL mimics the natural phonological loop by providing audible vocal echoes to take the place of subvocal rehearsals. In this system, the user talks to him/herself in short (1–2 second) phrases; the device records these phrases, stores them in electronic memory, and then repeats— i.e., echoes—the phrases multiple times over an extended period. Two versions of this device have been developed: the Echo‐APL and the Rearticulation‐APL. In the Echo‐APL, only echoing is involved. In the Rearticulation‐APL, however, the user re‐vocalizes (rearticulates) the phrase in response to an audible cue. The device repeats the cue until it detects (hears) the re‐vocalization. Future research and development of the APL will require extensive testing and careful evaluation of possible echo-schedules: the predefined program controlling inter‐echo time intervals and echo‐amplitude (echo loudness). The APL essentially exteriorizes the silent phonological loop and makes it audible. It is a system that helps the user to “talk to him/herself” to keep ideas in mind.
Lanthanum molybdenum oxide: Low-temperature synthesis and characterization
Authors: Basu S. , Devi P. Sujatha , Maiti H.S. , Lee Y. , Hanson J.C.
Published: May 2006

A recently developed fast oxide ion conductor, namely lanthanum molybdenum oxide (La2Mo2O9, LAMO), was synthesized instantaneously by a citrate-nitrate auto-ignition process at a fixed citrate to nitrate ratio of 0.3 and characterized by thermal analysis, x-ray diffraction, impedance spectroscopy, and thermal expansion measurements. Crystalline LAMO has formed instantaneously during the combustion process. The signature of the order–disorder transition of stoichiometric LAMO around 570 °C was evident from differential thermal analysis, differential scanning calorimetry electrical conductivity, and thermal expansion measurements. Though the in situ x-ray measurements did not indicate any clear evidence of a phase transition, a stepwise change in the lattice parameter near the vicinity of the transition temperature was apparent thereby confirming the phase transition to be of first order in nature. The thermal expansion coefficient of LAMO was calculated to be 13.92 × 10−6/°K at 950 °C. The present method formed phase pure LAMO instantaneously and produced sintered samples with high conductivity, namely, 0.052 S/cm at 800 °C and 0.08 S/cm at 950 °C compared to LAMO prepared through various other solution routes.
Two-dimensional imaging of the potential distribution within a core/shell nanowire by electron holography
Authors: Chung Jayhoon , Rabenberg Lew
Published: May 2006

Electrostatic potentials within a core/shell nanowire structure, composed of an intrinsic germanium core surrounded by its oxide and a heavily doped germanium shell, were investigated by electron holographic analysis on its cross-section. The potential distribution resulting from interface charges as well as dopants was successfully imaged. The surface potential, screening length, and doping concentration for the heavily doped germanium shell were determined quantitatively from the potential image. These characteristics were compared with values obtained from a numerical solution of Poisson's equation.
Inhomogeneous nano-mechanical properties in the multi-phase microstructure of long-term aged type 316 stainless steel
Authors: Ohmura T. , Tsuzaki K. , Sawada K. , Kimura K.
Published: May 2006

Microstructure-related local deformation behavior was evaluated using nanoindentation techniques for a type 316 austenitic stainless steel used in energy generation plants. The sample was aged for 39,332 h (4.5 years) at 700 °C. The microstructure included the σ phase precipitated at grain boundaries and in grain interiors. The nanohardnesses of the σ phase and the matrix in the aged and virgin samples were evaluated quantitatively. The hardness of the σ phase was found to be extremely high in the order of 17 GPa, which is much higher than the value of about 3.4 GPa for the matrix in the aged sample. The hardnesses of the σ phase at the grain boundary and the adjoining matrix were the same as those in the grain interior. Moreover, the hardness of the matrix of the aged sample was about 30% lower than that of the virgin sample while the Vickers hardness as a macroscopic strength of the aged sample was about 45% higher than that of the virgin one. The deformation and fracture behavior in a local region was discussed in terms of the inhomogeneous mechanical properties in the multi-phase microstructure.
Deformation behavior of Zr–Al–Cu–Ni–Sn metallic glasses
Authors: Bae D.H. , Lee S.W. , Kwon J.W. , Yi S. , Park J.S.
Published: May 2006

A highly deformable Zr–Al–Cu–Ni–Sn alloy system without any catastrophic failure has been developed and the underling mechanism for exceptional plasticity has been investigated in terms of structural characteristics and atomic movement kinetics. The as-cast Zr61.7Al8Ni13Cu17Sn0.3bulk metallic glass has many local nanoscale ordering features. They can play a critical role in nucleating abundant shear bands that sufficiently accommodate global plasticity. During deformation at room temperature, the ordered regions do not grow, providing a structural stability, possibly from the sluggish atomic movement kinetics. Thermal activation energy for crystallization of the Zr61.7Al8Ni13Cu17Sn0.3alloy is estimated as 3.96 eV, which is about 2.8 times higher than that of the Z41.2Ti13.8Cu12.5Ni10Be22.5alloy [Vitreloy 1 (Vit1)] and the dynamic mass flow rate is around 10 times slower than that of Vit1. A thermomechanical estimation of compressive strain rates under constant stress shows a sluggish atomic movement upon the addition of Sn.