bluuebunny/crossref_metadata_2025 huggingface dataset:
The psychological and physiological responses of sedentary individuals to prescribed and preferred intensity exercise
Authors: Parfitt Gaynor , Rose Elaine A. , Burgess William M.
Published: January 2006

Objectives Affective valence responses to exercise may influence adherence. According to a newly proposed dual‐mode model, affective responses have been proposed to vary depending on whether exercise is undertaken above or below the anaerobic threshold. With the model in mind, the study objectives were to explore the impact of an above‐lactate, below‐lactate, and self‐selected exercise condition on acute affective responses in sedentary individuals.

Design Using a repeated measures design, 12 volunteers participated in two prescribed intensity exercise conditions (above and below‐lactate threshold) and one self‐selected intensity exercise condition. The three conditions were randomized.

Method An incremental walking protocol was used to identify exercise intensities that would elicit above‐ and below‐lactate threshold work rates for each participant. The exercise conditions were completed on different days and each lasted for 20 minutes. Physiological and affective responses were recorded pre‐exercise, during exercise, and post‐exercise.

Results Affective responses were more negative in the above‐lactate condition during exercise compared with the below‐lactate and self‐selected conditions. There were no differences between the conditions post‐exercise. Participants exercised around the lactate threshold and at a significantly higher intensity in the self‐selected compared with the below‐lactate condition. Inter‐individual variability in responses was greatest below the lactate threshold, with similar levels of variability in the self‐selected and above‐lactate conditions.

Conclusions Data are consistent with the proposals of the dual‐mode model and support the use of self‐selected intensity with sedentary individuals to promote positive affective responses.
The eternal quest for optimal balance between maximizing pleasure and minimizing harm: The compensatory health beliefs model
Authors: Rabia Marjorie , Knäuper Bärbel , Miquelon Paule
Published: January 2006

Particularly in the health domain, humans thrive to reach an equilibrium between maximizing pleasure and minimizing harm. We propose that a cognitive strategy people employ to reach this equilibrium is the activation of Compensatory Health Beliefs (CHBs). CHBs are beliefs that the negative effects of an unhealthy behaviour can be compensated for, or “neutralized,” by engaging in another, healthy behaviour. “I can eat this piece of cake now because I will exercise this evening” is an example of such beliefs. Our theoretical framework aims at explaining why people create CHBs and how they employ CHBs to regulate their health behaviours. The model extends current health behaviour models by explicitly integrating the motivational conflict that emerges from the interplay between affective states (i.e., cravings or desires) and motivation (i.e., health goals). As predicted by the model, previous research has shown that holding CHBs hinder an individual's success at positive health behaviour change, and may explain why many people fail to adhere to behaviour change programs such as dieting or exercising. Moreover, future research using the model and implications for possible interventions are discussed.
Deactivation of Phosphorylated and Nonphosphorylated Rhodopsin by Arrestin Splice Variants
Authors: Burns Marie E. , Mendez Ana , Chen Ching-Kang , Almuete Aileen , Quillinan Nidia , Simon Melvin I. , Baylor Denis A. , Chen Jeannie
Published: January 2006

Arrestins constitute a family of small cytoplasmic proteins that mediate deactivation of G-protein-coupled receptors (GPCRs) and are known to be essential for cascade inactivation and receptor desensitization. Alternative splicing produces an array of arrestin gene products that have widely different specificities for their cognate receptorsin vitro, but the differential functions of these splice variantsin vivoare essentially unknown. Bovine rod photoreceptors express two splice variants of visual arrestin (p44 and p48) that display different affinities for the GPCR rhodopsin. To determine the functions of these splice variants in intact cells, we expressed a transgene encoding either a truncated form of murine arrestin (mArr1–369, or m44) or the long (p48) isoform in mouse rods lacking endogenous arrestin (Arr–/–). Morphological analysis showed that expression of either variant attenuated the light-induced degeneration that is thought to result from excessive cascade activity in Arr–/–rods. Suction electrode recordings from individual rods indicated that the expression of either m44 or p48 splice variants could restore normal kinetics to Arr–/– dim flash responses, indicating that both isoforms can bind to and quench phosphorylated rhodopsin rapidly. To our surprise, only the full-length variant was able to alter the kinetics of responses in rods lacking both arrestin and rhodopsin kinase, indicating that p48 can also quench the activity of nonphosphorylated rhodopsin.
Requirement of Adenylate Cyclase 1 for the Ephrin-A5-Dependent Retraction of Exuberant Retinal Axons
Authors: Nicol Xavier , Muzerelle Aude , Rio Jean Paul , Métin Christine , Gaspar Patricia
Published: January 2006

The calcium-stimulated adenylate cyclase 1 (AC1) has been shown to be required for the refinement of the retinotopic map, but the mechanisms involved are not known. To investigate this question, we devised a retinotectal coculture preparation that reproduces the gradual acquisition of topographic specificity along the rostrocaudal axis of the superior colliculus (SC). Temporal retinal axons invade the entire SC at 4 din vitro(DIV) and eliminate exuberant branches caudally by 12 DIV. Temporal and nasal axons form branches preferentially in the rostral or caudal SC, respectively. Retinal explants from AC1-deficient mice, AC1brl/brl, maintain exuberant branches and lose the regional selectivity of branching when confronted with wild-type (WT) SC. Conversely, WT retinas correctly target AC1brl/brlcollicular explants. The effects of AC1 loss of function in the retina are mimicked by the blockade of ephrin-A5 signaling in WT cocultures. Video microscopic analyses show that AC1brl/brlaxons have modified responses to ephrin-A5: the collapse of the growth cones occurs, but the rearward movement of the axon is arrested. Our results demonstrate a presynaptic, cell autonomous role of AC1 in the retina and further indicate that AC1 is necessary to enact a retraction response of the retinal axons to ephrin-A5 during the refinement of the retinotopic map.
Two Signaling Pathways Regulate the Expression and Secretion of a Neuropeptide Required for Long-Term Facilitation inAplysia
Authors: Hu Jiang-Yuan , Wu Fang , Schacher Samuel
Published: January 2006

Activation of several signaling pathways contributes to long-term synaptic plasticity, but how brief stimuli produce coordinated activation of these pathways is not understood. InAplysia, the long-term facilitation (LTF) of sensory neuron synapses by 5-hydroxytryptamine (serotonin; 5-HT) requires the activation of several kinases, including mitogen-activated protein kinase (MAPK). The 5-HT-enhanced secretion of the sensory neuron-specific neuropeptide sensorin mediates the activation of MAPK. We find that stimulus-induced activation of two signaling pathways, phosphoinositide 3-kinase (PI3K) and type II protein kinase A (PKA), regulate sensorin secretion and responses. Treatment with 5-HT produces a rapid increase in sensorin synthesis, especially at varicosities, which precedes the secretion of sensorin. PI3K inhibitor and rapamycin block LTF and the rapid synthesis of sensorin at varicosities even in the absence of sensory neuron cell bodies. Secretion of the newly synthesized sensorin from the varicosities and activation of the autocrine responses of sensorin to produce LTF require type II PKA interaction with AKAPs (A-kinase anchoring proteins). Thus, long-term synaptic plasticity is produced when multiple signaling pathways that are important for regulating distinct cellular functions are activated in a specific sequence and recruit the secretion of a neuropeptide to activate additional critical pathways.
Ermin, A Myelinating Oligodendrocyte-Specific Protein That Regulates Cell Morphology
Authors: Brockschnieder Damian , Sabanay Helena , Riethmacher Dieter , Peles Elior
Published: January 2006

Oligodendrocytes form an insulating multilamellar structure of compact myelin around axons, thereby allowing rapid propagation of action potentials. Despite the considerable clinical importance of myelination, little is known about the molecular mechanisms that enable oligodendrocytes to generate their specialized membrane wrapping. Here, we used microarray expression profiling of oligodendrocyte-ablated mutant mice to identify new glial molecules that are involved in CNS myelination. This effort resulted in the identification of Ermin, a novel cytoskeletal molecule that is exclusively expressed by oligodendrocytes. Ermin appears at a late stage during myelination, and in the mature nerves, it is localized to the outer cytoplasmic lip of the myelin sheath and the paranodal loops. In cultured oligodendrocytes, Ermin becomes visible in well differentiated MBP-positive cells, where it is concentrated at the tip of F-actinrich processes (termed “Ermin spikes”). Ectopic expression of Ermin, but not of a mutant protein lacking its actin-binding domain, induced the formation of numerous cell protrusions and a pronounced change in cell morphology. Our results demonstrate that Ermin is a novel marker of myelinating oligodendroglia and suggest that it plays a role in cytoskeletal rearrangements during the late wrapping and/or compaction phases of myelinogenesis.
Hippocampus-Mediated Activation of Superficial and Deep Layer Neurons in the Medial Entorhinal Cortex of the Isolated Guinea Pig Brain
Authors: Gnatkovsky Vadym , de Curtis Marco
Published: January 2006

The entorhinal cortex (EC) is regarded as the structure that regulates information flow to and from the hippocampus. It is commonly assumed that superficial and deep EC neurons project to and receive from the hippocampal formation, respectively. Anatomical evidences suggest that both the hippocampal output and deep EC neurons also project to superficial EC layers. To functionally characterize the interlaminar synaptic EC circuit entrained the by hippocampal output, we performed simultaneous intracellular recordings and laminar profile analysis in the medial EC (m-EC) of thein vitroisolated guinea pig brain after polysynaptic hippocampal activation by lateral olfactory tract (LOT) stimulation. Optical imaging of voltage-generated signals confirmed that the LOT-evoked hippocampus-mediated response is restricted to the m-EC. The hippocampal output generated an extracellular current sink in layers V–VI, coupled with an EPSP in deep neurons. Deep neuron firing was terminated by a biphasic IPSP. The earliest response observed in superficial layer neurons was characterized by a feedforward IPSP of circa 100 ms (–69 ± 1.3 mV reversal potential) abolished by local application of 1 mmbicuculline. The feedforward IPSP was followed by a delayed EPSP blocked by AP-5 (100 μm), presumably mediated by deep-to-superficial m-EC connections.

Our findings demonstrate that superficial m-EC cells are inhibited by the hippocampal output via a feedforward pathway that prevents activity reverberation in the hippocampal–EC–hippocampal loop. We propose that such inhibition could serve as a protective mechanism to prevent epileptic hyperexcitability.
Organization of the Presynaptic Active Zone by ERC2/CAST1-Dependent Clustering of the Tandem PDZ Protein Syntenin-1
Authors: Ko Jaewon , Yoon Chan , Piccoli Giovanni , Chung Hye Sun , Kim Karam , Lee Jae-Ran , Lee Hyun Woo , Kim Hyun , Sala Carlo , Kim Eunjoon
Published: January 2006

Presynaptic active zones contain a cytoskeletal matrix called the CAZ, which is thought to play a critical role in the regulation of active zone formation and neurotransmitter release. Recent studies have identified several CAZ components, but little is known about how they contribute to the molecular organization of active zones. Here, we report a novel PDZ [postsynaptic density-95/Discs large/zona occludens-1] interaction between the CAZ protein ERC2/CAST1 and the tandem PDZ protein syntenin-1, which is known to associate with diverse synaptic proteins, including glutamate receptor subunits, SynCAM, and β-neurexin. This interaction promotes the localization of syntenin-1 at presynaptic ERC2 clusters. In addition to the PDZ interaction, multimerization of both ERC2 and syntenin-1 mediates syntenin-1 clustering. These results suggest that ERC2 promotes presynaptic syntenin-1 clustering by two distinct mechanisms and that syntenin-1 may contribute to the molecular organization of active zones by linking ERC2 and other CAZ components to diverse syntenin-1-associated synaptic proteins.
Molecular and Morphological Heterogeneity of Neural Precursors in the Mouse Neocortical Proliferative Zones
Authors: Gal Jonathan S. , Morozov Yury M. , Ayoub Albert E. , Chatterjee Mitali , Rakic Pasko , Haydar Tarik F.
Published: January 2006

The proliferative ventricular zone (VZ) is the main source of projection neurons for the overlying cerebral neocortex. The number and diversity of neocortical neurons is determined, in part, by factors controlling the proliferation and specification of VZ cells during embryonic development. We used a variety of methods, includingin uteroelectroporation with specific cellular markers, computer-assisted serial EM cell reconstruction, and time-lapse multiphoton imaging to characterize the molecular and morphological characteristics of the VZ constituents and to capture their behavior during cell division. Our analyses reveal at least two types of dividing cells in the VZ: (1) radial glial cells (RGCs) that span the entire neocortical wall and maintain contact both at the ventricular and pial surfaces throughout mitotic division, and (2) short neural precursors (SNPs) that possess a ventricular endfoot and a basal process of variable length that is retracted during mitotic division. These two precursor cell classes are present concomitantly in the VZ, but their relative number changes over the course of cortical neurogenesis. Moreover, the SNPs are morphologically, ultrastructurally and molecularly distinct from dividing RGCs. For example, SNPs are marked by their preferential expression of the tubulin α-1 promoter whereas RGCs instead express the glutamate–aspartate transporter and brain lipid binding protein promoters. In contrast to recent studies that suggest that RGCs are the sole type of VZ precursor, the present study indicates that the VZ in murine dorsal telencephalon is similar to that in human and nonhuman primates, because it contains multiple types of neuronal precursors.
Primary Reinforcing Effects of Nicotine Are Triggered from Multiple Regions Both Inside and Outside the Ventral Tegmental Area
Authors: Ikemoto Satoshi , Qin Mei , Liu Zhong-Hua
Published: January 2006

Nicotine is thought to be the key substance responsible for tobacco-smoking habits and appears to trigger reinforcement via the ventral tegmental area (VTA). Recently, multiple anatomical substrates for drug reinforcement have been identified in the vicinity of the ventral midbrain. In addition to the posterior portion of the VTA, the central linear nucleus raphé and the supramammillary nucleus of the posterior hypothalamus mediate drug reinforcement. Using intracranial self-administration procedures, we examined whether these regions mediate the reinforcing effects of nicotine. Rats learned to lever press for self-administration of nicotine into the posterior VTA, central linear nucleus, and supramammillary nucleus, suggesting a reinforcing action of nicotine in these regions. The rats did not self-administer nicotine into surrounding regions including the anterior VTA, substantia nigra, the region just dorsal to the posterior VTA, interpeduncular nucleus, or medial mammillary nucleus. The reinforcing effects of nicotine into the three brain regions were further confirmed by a two-lever discrimination procedure, in which rats learned to selectively respond between active and inactive levers. The reinforcing effects of nicotine administration into the posterior VTA, central linear nucleus, and supramammillary nucleus were blocked by coadministration of the nicotine receptor antagonist mecamylamine. The reinforcing effects of nicotine into the posterior VTA or central linear nucleus were attenuated by coadministration of the D2receptor agonist quinpirole. These findings demonstrate that nicotine reinforcement involves multiple regions both inside and outside the VTA.
Synthesis, crystal structure and theoretical studies of aryltellurenyl tetramethylthiourea(tmtu) iodine complexes: Ph-Te(tmtu)I (1) and β-naphtyl-Te(tmtu)I (2)
Authors: Schulz Lang Ernesto , Ledesma Gabriela Nanci , Abram Ulrich , Vega-Teijido Maurício , Caracelli Ignez , Zukerman-Schpector Julio
Published: January 2006

(1) C11H17IN2STe, M
r = 463.83, P21/n, a = 7.6582(8), b = 13.8008(9), c = 15.026(3) Å, β = 96.233(12)°, Z = 4, R
1 = 0.0318. (2) C15H19IN2STe, M
r = 513.88, P21/n, a = 8.434(5), b = 11.697(5), c = 18.472(5) Å, β = 98.556(5)°, Z = 4, R
1 = 0.0236. The synthesis of the aryltellurenyl N,N′-tetramethylthiourea (tmtu) iodide has been performed by ligand exchange with potassium iodide and the corresponding aryltellurenyl(tmtu) bromide. In both structures the tellurium atom is primarily three-coordinated, being bonded to a carbon atom of the organic ring and, in directions nearly perpendicular to the Te—C bond, to one tmtu sulfur atom and one iodine. In addition there are Te…secondary bonds, joining the molecules in centrosymmetric dimers, which in turn are joined through C—H…I and C—H…S interactions, in (1) and (2) respectively.
Ventricular Septal Defect With Secondary Left Ventricular–to–Right Atrial Shunt Is Associated With a Higher Risk for Infective Endocarditis and a Lower Late Chance of Closure
Authors: Wu Mei-Hwan , Wang Jou-Kou , Lin Ming-Tai , Wu En-Ting , Lu Frank Leigh , Chiu Sheunn-Nan , Lue Hung-Chi
Published: January 2006

OBJECTIVE. Although ventricular septal aneurysm may diminish or even close the shunt through the ventricular septal defect (VSD), developing a left ventricular–to–right atrial (LV-RA) shunt may be unfavorable. This study sought to clarify this issue on the basis of an extended observation of such patients.

METHODS. Sixty-eight patients (1201 patient-years) who had small perimembranous VSD and LV-RA shunt and were not operated on before 6 years of age were studied.

RESULTS. The onset age of LV-RA shunt was 5.8 ± 3.3 years, with clinical improvement later observed in 23 (34%). The murmur disappeared and showed spontaneous closure in 5 (7%). Seven episodes of infective endocarditis occurred in 6 (8.7%, or 58 per 10000 patient-years), with 2 receiving surgery. Another 4 received surgery during follow-up. With echocardiography, aneurysmal transformation involving the anterior and septal leaflets of tricuspid valve (double sac) was found in 56 (85%), whereas only the septal leaflet (single sac) was involved in 10. Patients with double sac were less likely to show improvement, whereas patients who had superior QRS axis and were female showed clinical improvement more frequently.

CONCLUSIONS. VSD with secondary LV-RA shunt is associated with a higher risk for infective endocarditis but still has a low chance for late improvement and even closure.
Analysis of Chopping Cylinder Drive Torque Components
Authors: Szendrő Péter , Nagy József , Vincze Gyula
Published: January 2006

Chopping biomaterials is an energy consuming process where considerable losses occur because of friction and the compaction of the material. The objective of the paper reported here is to show an energy saving chopping cylinder drive mechanism and to analyze the variations in the drive torque of the chopping cylinder. The chopping mechanism consists of a flexible drive mechanism. Field experiments were performed with a chopper fitted with such a mechanism and the components of the drive torque were determined from the results. The random excitation of the flexible drive mechanism (“multikator”) is caused by the variations in the transport of the material to the chopping cylinder. Consequently there are variations in the angular speed of the chopping cylinder. These variations cause the edgewise vibration of the cutting knives and therefore the energy saving effect. The analysis of random components of cutting torque as a function of time could give an advanced method for designing machine parts operated under dynamic load. Therefore, the critical load, or stress can be calculated by the method developed. Furthermore, the lifetime and the breakdown of the machine parts can be predicted.
A Theoretical Elucidation on the Solvent‐dependent Photosensitive Behaviors of C60
Authors: Shen Liang , Ji Hong‐Fang , Zhang Hong‐Yu
Published: January 2006

In this paper, the solvent‐dependent photosensitive behaviors of fullerene (C60) were investigated in polar and nonpolar solvents by time‐dependent density functional theory (TD‐DFT) calculation. Based on the calculated physicochemical parameters on triplet state, it is revealed that excited‐state C60 only generates 1O2 via energy transfer in benzene, but can give birth to O2˙− and 1O2 in water via energy transfer and electron transfer, respectively. Considering the fact that electron transfer is more favorable compared with energy transfer in polar biological systems, especially with the presence of electron donors, the O2˙−‐generating process will get predominant in physiological systems. These results account well for the experimental observations that O2˙− and ˙OH are primarily responsible for the photoinduced DNA cleavage by C60 under physiological conditions, whereas 1O2 plays a critical role in nonpolar solvents.
A Modified Box Trap Design for Sampling Emigrating Salmonid Smolts from Small Streams
Authors: Roth Robert N. , Orvos David R.
Published: January 2006

A box trap was constructed and used to collect juvenile steelhead Oncorhynchus mykiss in Spooner Creek, Erie County, New York, during the spring of 2000 and 2001. The trap was designed for use in streams with short waterfalls. It was utilized for approximately 70 d each spring and trapped 552 and 1,702 steelhead juveniles in 2000 and 2001, respectively. Approximately 5–75 steelhead per night were collected with negligible mortality, and streams were effectively sampled in discharges below 35 ft3/s. Trap efficiencies averaged 51% and 63% in 2000 and 2001, respectively. Problems were encountered during high-water periods, as high water caused the trap to become submerged and useless once the windows were plugged with forest litter. However, these episodes were rare. The modified box trap design presented here proved effective in a variety of conditions and should provide fisheries scientists an effective tool for sampling juveniles in smaller streams.
Evaluation of the Impacts of Carlin Tags, Fin Clips, and Panjet Tattoos on Juvenile Atlantic Salmon
Authors: Dietrich Jason P. , Cunjak Richard A.
Published: January 2006

The potential impacts of marking techniques on juvenile Atlantic salmon Salmo salar were assessed in a hatchery and in the wild. Hatchery-reared parr ranging from 12.0 to 20.8 cm were marked with Carlin tags and fin-clipped. Anal, pelvic, or caudal fin clips were used to investigate the rate of fin regeneration. No mortality or tag loss occurred, and there was no significant change in condition factor between marked and unmarked treatments or among fish of different mark groups. Carlin tag wounds began to heal within 28 d. However, this was followed by a period where the majority of wounds became irritated, thus slowing the healing process; thereafter, the majority of individuals showed an accelerated healing that continued until the end of the hatchery experiment (146 d). Caudal fins showed the first signs of regeneration, and pelvic fins showed the greatest amount of regeneration by the end of the experiment (146 d). Anal fins showed significantly less fin regeneration than pelvic or caudal fin clips and so were used as a secondary mark in the field to investigate differences in survival and mark retention between Panjet tattoos and Carlin tags. Panjet-tattooed and Carlin-tagged smolts held for 24 h posthandling showed no difference in survival (97% overall), and mark retention was 100%. Recapture success was equivalent between tagged and tattooed individuals, and none of the recaptured smolts showed evidence of tag loss. The results of this study provide evidence of the efficacy in using anal fin clips, tattoos, and Carlin tags as marking techniques in fisheries research.
Detection of Uncured Visible Implant Elastomer Tags in Larval Pacific Lampreys
Authors: Stone Jen , McGree Michelle , Whitesel Timothy A.
Published: January 2006

Lampreys in the Columbia River basin are a conservation concern, and understanding their status is a priority among managers. Many population assessment techniques depend on the ability to tag fish so that these tags are retained for the duration of the study with minimal effect on survival. There are several methods for tagging small fishes in streams, including passive integrated transponders, coded wire tags, and visible implant elastomer (VIE) tags. Of these, VIE tags have not been extensively tested on larval or juvenile lampreys. We evaluated the performance of uncured VIE tags on ammocoetes of Pacific lampreys Lampetra tridentata in a laboratory experiment to determine tag detection and the influences of color and tag position on detection. Additionally, we examined the effects of transformation (ammocoete to macrophthalmia) on tag detection. Though survival was not specifically tested, 0 of the 84 lampreys died as a result of tagging. Tag detection was 87% after 168 d in lampreys that did not transform; in those that did transform, however, tag detection was reduced to 38%. Tag position did not affect detection, but red and orange tags were detected more consistently than green tags. Overall, uncured VIE tags can be used effectively to tag larval lampreys; however, studies that depend on long-term tag detection either should be conducted at a time when lampreys are not expected to transform or should only use ammocoetes that are not likely to transform during the study.
Abundance of Adult Saugers across the Wind River Watershed, Wyoming
Authors: Amadio Craig J. , Hubert Wayne A. , Johnson Kevin , Oberlie Dennis , Dufek David
Published: January 2006

The abundance of adult saugers Sander canadensis was estimated over 179 km of continuous lotic habitat across a watershed on the western periphery of their natural distribution in Wyoming. Three-pass depletions with raft-mounted electrofishing gear were conducted in 283 pools and runs among 19 representative reaches totaling 51 km during the late summer and fall of 2002. From 2 to 239 saugers were estimated to occur among the 19 reaches of 1.6–3.8 km in length. The estimates were extrapolated to a total population estimate (mean ± 95% confidence interval) of 4,115 ± 308 adult saugers over 179 km of lotic habitat. Substantial variation in mean density (range = 1.0–32.5 fish/ha) and mean biomass (range = 0.5–16.8 kg/ha) of adult saugers in pools and runs was observed among the study reaches. Mean density and biomass were highest in river reaches with pools and runs that had maximum depths of more than 1 m, mean daily summer water temperatures exceeding 20°C, and alkalinity exceeding 130 mg/L. No saugers were captured in the 39 pools or runs with maximum water depths of 0.6 m or less. Multiple-regression analysis and the information-theoretic approach were used to identify watershed-scale and instream habitat features accounting for the variation in biomass among the 244 pools and runs across the watershed with maximum depths greater than 0.6 m. Sauger biomass was greater in pools than in runs and increased as mean daily summer water temperature, maximum depth, and mean summer alkalinity increased and as dominant substrate size decreased. This study provides an estimate of adult sauger abundance and identifies habitat features associated with variation in their density and biomass across a watershed, factors important to the management of both populations and habitat.
Superposition of tectono-thermal episodes in the southern Cantabrian Zone (foreland thrust and fold belt of the Iberian Variscides, NW Spain)
Authors: Aller Jesus , Valín María Luz , García-López Susana , Brime Covadonga , Bastida Fernando
Published: January 2006

The combined use of the illite “crystallinity” Kübler index (KI) and the conodont colour alteration index (CAI) has revealed the existence of three thermal episodes in an area affected by thin-skin tectonics, close to the internal zones of the Variscan orogen in NW Spain. In the southernmost part of the study area, the first episode gave rise to a regional syntectonic Variscan metamorphism. The associated deformation involves the development of a slaty cleavage, which is mainly recognized in Precambrian rocks. Towards the foreland, the syntectonic metamorphism disappears and only an incipient burial metamorphism, giving rise to anchizonal conditions in the basal part of the thrust units, is observed.

Another metamorphic episode occurred close to the Carboniferous-Permian boundary in an extensional tectonic regime. This metamorphism is restricted to the northern part of the study area, where it reached anchizonal or epizonal conditions. It is associated with a subhorizontal or moderately north-dipping cleavage and can be considered as a late-Variscan episode.

The last thermal episode occurred during the Permian. It was produced by heat flow due to hydrothermal fluids, whose migration was favoured by faults. The effects of this episode are irregularly distributed, and they are apparent in the unconformable Stephanian rocks in which anchizonal or epizonal conditions were reached. It is interpreted as a post-Variscan episode.
The Carboniferous Baralacha La basaltic dykes (Upper Lahul, Ladakh) : remnants of an early rifting event along the Indian northern plate
Authors: Chauvet François , Lapierre Henriette , Bosch Delphine , Demant Alain , Bussy François , Vannay Jean-Claude , Mascle Georges H. , Brunet Pierre , Cotten Joseph , Keller Francine
Published: January 2006

The Lower Carboniferous Baralacha La basaltic dykes were emplaced along transtensional faults. The basalts exhibit tholeiitic and alkaline affinities. The tholeiites are TiO2-poor, moderately enriched in light rare earth (LREE), and display Nb and Ta negative and Th positive anomalies. The alkali basalts, compared to the tholeiites, have higher TiO2, rare earth and highly incompatible trace element contents and greater LREE enrichments. The Nd and Pb isotope compositions of the Baralacha La basalts suggest that they derive from the partial melting of an enriched OIB mantle source, characterized by a HIMU component, and contaminated by the lower continental crust. The Baralacha La dyke swarm represent the remnants of an early rifting event on the northern Indian passive margin.
Intermolecular Forces in the Self‐Assembly of Peptide Amphiphile Nanofibers
Authors: Stendahl J. C. , Rao M. S. , Guler M. O. , Stupp S. I.
Published: January 2006

Peptide amphiphile molecules (PAs) developed in our laboratory self‐assemble from aqueous media into three‐dimensional networks of bioactive nanofibers. Multiple non‐covalent interactions promote assembly of the supramolecular nanofibers and ultimately determine the bulk physical properties of the macroscopic gels. In this study, we use oscillatory rheology, Fourier‐transform infrared spectroscopy, and circular‐dichroism spectroscopy to better understand the assembly mechanism of a typical PA molecule known as PA‐1. Self‐assembly of PA‐1 is triggered by counterion screening and stabilized by van der Waals and hydrophobic forces, ionic bridging, and coordination and hydrogen bonding. The concentration, electronic structure, and hydration of counterions significantly influence self‐assembly and gel mechanical properties.
Synthesis of Polymer Bound Azabis(oxazoline) Ligands and their Application in Asymmetric Cyclopropanations
Authors: Werner Heiko , Herrerías Clara I. , Glos Michael , Gissibl Anja , Fraile Jose M. , Pérez Ignacio , Mayoral Jose A. , Reiser Oliver
Published: January 2006

Aza(bisoxazoline) ligands were attached to various polymeric supports and the resulting immobilized ligands were evaluated in copper(I)‐catalyzed asymmetric cyclopropanations. The efficiency of these transformations depends greatly on the polymeric support, on the protocol being applied for the immobilization of the ligands, and on the preparation of the catalysts.
Functional Resins as Hydrophilic Supports for Nanoclustered Pd(0) and Pd(0)‐Au(0) Catalysts Designed for the Direct Synthesis of Hydrogen Peroxide
Authors: Burato Claudio , Centomo Paolo , Rizzoli Maurizio , Biffis Andrea , Campestrini Sandro , Corain Benedetto
Published: January 2006

The commercial macroreticular cation exchanger resin Lewatit K2621/H+ and two gel‐type resins bearing SO3H and SMe functionalities are used to produce two acidic Pd(0)/resin(H+) and one non‐acidic Pd(0)‐Au(0)/resin catalysts that are tested in the direct synthesis of H2O2 in methanol/water (2.5 : 1) at −10 °C and moderate H2 and O2 pressures. Molar yields in H2O2 after 1.5 hours, range from 12.9% [Pd(0)‐Au(0)/resin] to 46% [Pd(0)/K2621/H+].
Mild Peroxidative Oxidation of Cyclohexane Catalyzed by Mono‐, Di‐, Tri‐, Tetra‐ and Polynuclear Copper Triethanolamine Complexes
Authors: Kirillov Alexander M. , Kopylovich Maximilian N. , Kirillova Marina V. , Karabach Evgeny Yu. , Haukka Matti , da Silva M. Fátima C. Guedes , Pombeiro Armando J. L.
Published: January 2006

The mono‐, di‐, tri‐, tetra‐ and polynuclear copper(II) triethanolamine (H3tea) complexes [Cu(H2tea)(N3)] (1), [Cu2(H2tea)2(XC6H4COO)2]⋅2 H2O (X=4‐H2a, 4‐CH32b, 3‐Cl2c), [Cu3(H2tea)2(4‐OC6H4COO)2(H2O)]⋅4H2O (3), [O⊂Cu4(tea)4(BOH)4][BF4]2(4) and [Cu2(H2tea)2{μ‐C6H4(COO)2‐1,4}n]⋅2n H2O (5), respectively, are highly active and selective catalysts or catalyst precursors for the peroxidative oxidation of cyclohexane, in acetonitrile, to a cyclohexanol and cyclohexanone mixture, by aqueous hydrogen peroxide in acidic medium (liquid biphasic catalysis) at room temperature and atmospheric pressure. The effects on the catalytic activity of various factors, e.g., the relative amounts of cyclohexane, oxidant, catalyst, solvent and nitric acid, reaction time, catalyst recycling and impact of both carbon‐ and oxygen‐centred radical traps (supporting mainly radical mechanisms) were investigated and allowed us to achieve yields and TONs up toca.39% and 380, respectively, corresponding to the most active copper systems so far reported for the oxidation of cyclohexane under mild conditions. The catalysts can be reused for recycling and, at least complex4maintains almost the same level of activity even after five reaction cycles. The preparation of the new complexes1, 2band2cby self‐assembly at room temperature, and their full characterization by IR spectroscopy, FAB‐MS+, elemental and X‐ray diffraction structural (for1and2c) analyses are also reported.
Solvent‐Free Chelation‐Assisted Catalytic CC Bond Cleavage of Unstrained Ketone by Rhodium(I) Complexes under Microwave Irradiation
Authors: Ahn Jeong‐Ae , Chang Duck‐Ho , Park Young Jun , Yon Ye Rim , Loupy André , Jun Chul‐Ho
Published: January 2006

A highly efficient CC bond cleavage of unstrained aliphatic ketones bearing β‐hydrogens with olefins was achieved using a chelation‐assisted catalytic system consisting of (Ph3P)3RhCl and 2‐amino‐3‐picoline by microwave irradiation under solvent‐free conditions. The addition of cyclohexylamine catalyst accelerated the reaction rate dramatically under microwave irradiation compared with the classical heating method.
Novel Chiral Sulphonato‐Salen‐Manganese(III)‐Pillared Hydrotalcite Catalysts for the Asymmetric Epoxidation of Styrenes and Cyclic Alkenes
Authors: Bhattacharjee Samiran , Anderson James A.
Published: January 2006

A novel chiral sulphonato‐salen‐manganese (III) complex has been prepared and intercalated into a Zn‐Al layered‐double hydroxide (LDH) structure. The resulting catalyst was found to be highly active and enantioselective in the epoxidation of various styrenes and cyclic alkenes when using a combination of pivalaldehyde and molecular oxygen at atmospheric pressure and room temperature. At 94% conversion, 1‐methyl‐1‐cyclohexene could be converted to epoxide with 68% ee and 90% selectivity with a turnover frequency (TOF) of 234 h−1, whereas 4‐methylstyrene was converted with 62% ee and 70% selectivity with a TOF of 327 h−1. In the case of styrenes and cyclic alkenes, TOF decreased as follows: α‐methylstyrene>4‐methylstyrene>styrene and 1‐methyl‐1‐cyclohexene>1‐phenyl‐1‐cyclohexene>cyclohexene. The catalyst could be recycled without detectable loss of efficiency.
Chiral Chromium(III) Porphyrins as Highly Enantioselective Catalysts for Hetero‐Diels–Alder Reactions Between Aldehydes and Dienes
Authors: Berkessel Albrecht , Ertürk Erkan , Laporte Cécile
Published: January 2006

Starting from enantiomerically pure 5,10,15,20‐tetrakis[(1S,4R,5R,8S)‐1,2,3,4,5,6,7,8‐octahydro‐1,4 : 5,8‐dimethanoanthracene‐9‐yl]porphyrin, treatment with CrCl2 and subsequent air oxidation afforded the corresponding Cr(III) complex, with chloride as counterion, in 96% yield. Anion exchange with AgBF4 gave the corresponding tetrafluoroborate. These hitherto unknown chiral chromium porphyrins are efficient and highly enantioselective catalysts for the hetero‐Diels–Alder reaction of aliphatic, aromatic, and heteroaromatic aldehydes with dienes of varying electron density. In the case of 1‐methoxy‐3‐(trimethylsilyloxy)butadiene (“Danishefsky's diene”), enantiomeric excesses >90% were achieved in a number of cases, with furfural affording the highest ee (97%). Metal‐coordinating aldehydes such as pyridine‐2‐carbaldehyde do not inactivate the Cr(III) porphyrin catalyst. The cycloaddition of less electron‐rich dienes (such as 1‐methoxybutadiene) is effected as well, affording diastereoselectivities up to >99 : 1, and enantiomeric excesses >80%.
Lipase‐Involved Strategy to the Enantiomers of 4‐Benzyl‐β‐Lactam as a Key Intermediate in the Preparation of β‐Phenylalanine Derivatives
Authors: Li Xiang‐Guo , Kanerva Liisa T.
Published: January 2006

A simple chemoenzymatic method for the preparation of the enantiomers of 4‐benzyl‐β‐lactam (4‐benzylazetidin‐2‐one) from allylbenzene has been described. The enantiomers of this key intermediate have been used to produce the corresponding enantiomers of β‐phenylalanine and N‐Boc‐protected β‐phenylalanine amide through the simple cleavage of the lactam ring by acid‐catalyzed hydrolysis and by ammonolysis, respectively. Burkholderia cepacia lipase‐catalyzed kinetic double resolution techniques were responsible for achieving enantiopurity in the products. This was performed through the acylation of N‐hydroxymethylated β‐lactam followed by the butanolysis of the obtained (S)‐ester. Direct lipase‐catalyzed cleavage of the β‐lactam ring has also been studied.
A General and Efficient Method for the Preparation of β‐Enamino Ketones and Esters Catalyzed by Indium Tribromide
Authors: Zhang Zhan‐Hui , Yin Liang , Wang Yong‐Mei
Published: January 2006

A variety of β‐enamino ketones and esters have been synthesized in high to exellent yields by reacting β‐dicarbonyl compounds with amines in the presence of a catalytic amount of indium tribromide. The reaction proceeds smoothly at room temperature in a short reaction time under solvent‐free conditions.
Remarkable Anion and Cation Effects on Stille Reactions in Functionalised Ionic Liquids
Authors: Chiappe Cinzia , Pieraccini Daniela , Zhao Dongbin , Fei Zhaofu , Dyson Paul J.
Published: January 2006

Task‐specific ionic liquids bearing nitrile functional groups attached to the cation and nitrogen‐donor‐containing anions strongly affect the efficiency of the Stille cross‐coupling, influencing the nature of the catalyst and its stability. The relative strengths of the coordinating power of the cations and anions are varied and compared, and under certain conditions nanoparticles are observed.
Filtration‐Free Recyclable Catalytic Asymmetric Dihydroxylation Using a Ligand Immobilized on Magnetic Mesocellular Mesoporous Silica
Authors: Lee Daewon , Lee Jinwoo , Lee Honggeun , Jin Sunmi , Hyeon Taeghwan , Kim B. Moon
Published: January 2006

A new magnetic mesocellular mesoporous silica support featuring a 3D open‐pore structure has been developed for highly efficient, filtration‐free recycling of chiral ligands for catalytic asymmetric dihydroxylation. Reactions using the ligand immobilized on this magnetic silica system exhibited almost the same reactivity and enantioselectivity as those obtained in the homogeneous reaction. Magnetically recovered ligand could be recycled eight times with good to excellent conservation of reaction rates and enantioselectivities.
Insights into the “isolation” of the Basques: mtDNA lineages from the historical site of Aldaieta (6th–7th centuries AD)
Authors: Alzualde Ainhoa , Izagirre Neskuts , Alonso Santos , Alonso Antonio , Albarrán Cristina , Azkarate Agustin , de la Rúa Concepción
Published: January 2006

We analyzed the hypervariable region I (HVR‐I) sequence variability of the mitochondrial DNA (mtDNA) of individuals buried at Aldaieta (6th–7th centuries AD) in order to find out more about the biosocial implications of this cemetery. The results, fully authenticated by means of diverse criteria (analysis of duplicates, replication in an independent laboratory, quantification of target DNA, and sequencing and cloning of polymerase chain reaction products), suggest that Aldaieta largely consists of autochthonous individuals who shared common funereal customs with the late Ancient North Pyrenean cemeteries of Western Europe (the Reihengräberfelder), a cultural influence possibly accompanied by a certain genetic flow. Furthermore, the distribution of mtDNA lineages in the cemetery highlighted the existence of a significant number of family relationships, supporting the belief that it was a stable settlement and not a group that had haphazardly settled in the area. Finally, this paper stresses the importance of ancient DNA data for reconstructing the biological history of human populations, rendering it possible to verify certain hypotheses based solely on current population data. The presence at Aldaieta of an mtDNA lineage originating in Northwest Africa testifies to the existence of contact between the Iberian Peninsula and Northwest Africa prior to the Moorish occupation. Both this latter discovery and the high frequency of haplogroup J at the Aldaieta cemetery raise questions about the generally accepted belief that, since ancient times, the influence of other human groups has been very scarce in the Basque Country. Am J Phys Anthropol, 2006. © 2006 Wiley‐Liss, Inc.
Polymers based on phenyl methacrylate: Synthesis via atom transfer radical polymerization, characterization, monomer reactivity ratios, and thermal stabilities
Authors: Demirelli Kadir , Kaya Esin , Coşkun Mehmet
Published: January 2006

The atom transfer radical copolymerization of phenyl methacrylate (PMA) with methyl methacrylate (MMA) was performed in bulk at 110°C in the presence of ethyl 2‐bromoacetate, cuprous bromide (CuBr), and 2,2′‐bipyridine. Also, free‐radical copolymerization of PMA with MMA was carried out in the presence of 2,2′‐azobisisobutyronitrile in 1,4‐dioxane solvent at 60°C. The copolymers were characterized by IR, 1H NMR, and 13C NMR techniques. The compositions of the copolymers were determined from the 1H NMR spectra. The in situ addition of ethylmethacrylate to a macroinitiator—poly(phenyl methacrylate)[Mn = 10,560, Mw/Mn = 1,68]—afforded an AB‐type block copolymer. The molecular weight and molecular weight distribution were obtained using gel permeation chromatography (GPC). The polydispersities for the living copolymer (48 mol % PPMA units) and the free‐radical copolymer (42 mol % PPMA) were 1.43 and 2.40, respectively. For the two copolymerization systems, the monomer reactivity ratios were obtained by using both Kelen–Tüdös and Fineman–Ross equations. The initial decomposition temperatures of the resultant copolymers decreased with increasing mole fraction of PMA, which indicate that heat resistance of copolymer improved by decreasing the PMA units. Blends of poly(PMA) and poly(MMA) obtained via ATRP method were prepared by casting films from dichloromethane solution. The blends were characterized by differential thermal analysis or differential scanning calorimetry and thermogravimetry. The results were comparable with each other. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3344–3354, 2006
Different effects of tri(acryloyloxyethyl) phosphate on the thermal degradation of photopolymerized epoxy acrylate and polyurethane acrylate films
Authors: Liang Hongbo , Huang Zhanguang , Shi Wenfang
Published: January 2006

Tri(acryloyloxyethyl) phosphate (TAEP) was blended in different ratios with epoxy acrylate EB600 and polyurethane acrylate EB270 to obtain a series of UV curable flame retardant resins. The thermal degradation mechanisms of their cured films in air were studied by thermogravimetric analysis, in situ Fourier‐transform infrared spectroscopy, and direct pyrolysis/mass spectrometry measurements. The results showed that the phosphate group in TAEP first degraded to form poly(phosphoric acid) before the degradation of EB600. Then, the formed poly(phosphoric acid) effectively promoted the conversion of EB600 to form char, which prevented the sample from further burning. However, urethane group in EB270 degraded simultaneously with phosphate group in TAEP, leading to not effectively increase the conversion of EB270 to char during the thermal degradation. It was thus found that the addition of TAEP more effectively improved the thermal stability, flame retardance, and the char yield during combustion of EB600 than those of EB270. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3130–3137, 2006
Molecular morphology of petaloid bases of PET bottles: A small‐angle X‐ray scattering study
Authors: Hanley Tracey , Sutton David , Cookson David , Kosior Edward , Knott Robert
Published: January 2006

Small‐angle X‐ray scattering (SAXS) studies were undertaken to explore possible morphological explanations for poor mechanical strength in the petaloid bases of poly(ethylene terephthalate) (PET) bottles. The bottles were manufactured using a two‐stage injection stretch blow molding process. Splitting of PET bottle bases under load is both inconvenient and expensive. In this study, SAXS data were collected with a 100 μm square X‐ray beam to establish the molecular morphology as a function of position across the base topology. An amorphous region was identified in the base center (i.e., close to the injection gate of the preform) with biaxially orientated, semicrystalline regions in the feet and valleys of the bottle bases. For bottles that had split under load, the transition between these two regions displayed uniaxial orientation that would lead to reduced mechanical strength in the circumferential direction. Reasons for this effect are explored. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 99: 3328–3335, 2006