bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of innervation‐zone distribution on estimates of average muscle‐fiber conduction velocity
Authors: Nielsen Mogens , Graven‐Nielsen Thomas , Farina Dario
Published: October 2007

Muscle‐fiber conduction velocity (MFCV) may be a diagnostic variable, but the factors affecting its estimate from surface electromyographic (SEMG) signals are still not fully understood. We investigated the effect of innervation‐zone distribution on estimates of average MFCV from simulated SEMG signals. Single‐fiber action potentials were simulated using a computer model that describes an idealized cylindrical volume conductor comprised of bone, muscle, subcutaneous, and skin tissues. A model describing the characteristics and control of a motor‐neuron pool was used to simulate 60 s of SEMG. Five innervation‐zone distributions, inclined with respect to the fiber direction, were simulated within the muscle tissue, based on data from the literature and an experimental analysis. Two parameters were varied concurrently: (1) excitation level (5%–100%, 5% increments); and (2) subcutaneous tissue thickness (4 and 10 mm). The MFCV estimates were affected by the distribution of innervation zones with bias varying with excitation level and thickness of subcutaneous tissue. The MFCV estimates ranged from 3.95 to 11.67 m/s for single‐differential and from 3.99 to 5.23 m/s for double‐differential recordings when all simulated motor units were assigned the same conduction velocity of 4 m/s. Amplitude and characteristic spectral frequencies were also influenced by the distribution of innervation zones. The effect of innervation‐zone distribution on MFCV estimates is thus substantial and may be a significant confounding factor in experimental and clinical studies on muscles with diffuse innervation zones. Muscle Nerve, 2007
Effects of CRF2R agonist on tumor growth and cachexia in mice implanted with Lewis lung carcinoma cells
Authors: Argilés Josep M. , Figueras Maite , Ametller Elisabet , Fuster Gemma , Olivan Mireia , de Oliveira Cibely Cristine Fontes , López‐Soriano Francisco J. , Isfort Robert J. , Busquets Sílvia
Published: October 2007

Previous studies have demonstrated an effect of corticotropin‐releasing factor 2 receptor (CRF2R) agonists in the maintenance of skeletal muscle mass. The aim of this study was to evaluate the effects of a CRF2R agonist in preserving skeletal muscle in a mouse cachexia model. Implantation of a fast‐growing tumor to mice (Lewis lung carcinoma) resulted in a clear cachectic state characterized by a profound muscle wasting. We found that administration of a CRF2R agonist (PG‐873637) at 100 μg/kg/day by means of osmotic minipumps to tumor‐bearing mice resulted in beneficial effects on muscle weight loss. Thus, muscle loss was partially reversed by the CRF2R agonist at different stages of tumor growth (at day 14 after tumor inoculation: 12% in tibialis posterior; 9% in gastrocnemius; and 48% in soleus). Moreover, the CRF2R agonist significantly reduced both the number of metastases and their mass (at day 19 after tumor inoculation: 66% and 61%, respectively). These data suggest a potentially beneficial effect of the CRF2R agonist in preserving skeletal muscle during cancer cachexia and open a line of research for the development of new therapeutic approaches for the treatment of muscle wasting associated with cancer. Muscle Nerve, 2007
Novel mutation in KCNA1 causes episodic ataxia with paroxysmal dyspnea
Authors: Shook Steven J. , Mamsa Hafsa , Jen Joanna C. , Baloh Robert W. , Zhou Lan
Published: October 2007

Episodic ataxia type 1 (EA1) is an autosomal‐dominant neurological disease caused by point mutations in the potassium channel–encoding gene KCNA1. It is characterized by attacks of ataxia and continuous myokymia. Respiratory muscle involvement has not been previously reported in EA1. We clinically evaluated a family with features of EA1 and paroxysmal shortness of breath. Coding and flanking intronic regions of KCNA1 were sequenced. We identified a novel 3‐nucleotide deletion mutation in KCNA1 in the affected individuals. Our findings of a deletion mutation with unusual respiratory muscle involvement expand the genetic and clinical spectrum of EA1. Muscle Nerve, 2007
The HhH domain of the human DNA repair protein XPF forms stable homodimers
Authors: Das Devashish , Tripsianes Konstantinos , Jaspers Nicolaas G. J. , Hoeijmakers Jan H. J. , Kaptein Robert , Boelens Rolf , Folkers Gert E.
Published: October 2007

The human XPF‐ERCC1 protein complex plays an essential role in nucleotide excision repair by catalysing positioned nicking of a DNA strand at the 5′ side of the damage. We have recently solved the structure of the heterodimeric complex of the C‐terminal domains of XPF and ERCC1 (Tripsianes et al., Structure 2005;13:1849–1858). We found that this complex comprises a pseudo twofold symmetry axis and that the helix–hairpin–helix motif of ERCC1 is required for DNA binding, whereas the corresponding domain of XPF is functioning as a scaffold for complex formation with ERCC1. Despite the functional importance of heterodimerization, the C‐terminal domain of XPF can also form homodimers in vitro. We here compare the stabilities of homodimeric and heterodimeric complexes of the C‐terminal domains of XPF and ERCC1. The higher stability of the XPF HhH complexes under various experimental conditions, determined using CD and NMR spectroscopy and mass spectrometry, is well explained by the structural differences that exist between the HhH domains of the two complexes. The XPF HhH homodimer has a larger interaction interface, aromatic stacking interactions, and additional hydrogen bond contacts as compared to the XPF/ERCC1 HhH complex, which accounts for its higher stability. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Mn/Fe superoxide dismutase interaction fingerprints and prediction of oligomerization and metal cofactor from sequence
Authors: Wintjens René , Gilis Dimitri , Rooman Marianne
Published: October 2007

Fe‐ and Mn‐containing superoxide dismutase (sod) enzymes are closely related and similar in both amino acid sequence and structure, but differ in their mode of oligomerization and in their specificity for the Fe or Mn cofactor. The goal of the present work is to identify and analyze the sequence and structure characteristics that ensure the cofactor specificities and the oligomerization modes. For that purpose, 374 sod sequences and 17 sod crystal structures were collected and aligned. These alignments were searched for residues and inter‐residue interactions that are conserved within the whole sod family, or alternatively, that are specific to a given sod subfamily sharing common characteristics. This led us to define key residues and inter‐residue interaction fingerprints in each subfamily. The comparison of these fingerprints allows, on a rational basis, the design of mutants likely to modulate the activity and/or specificity of the target sod, in good agreement with the available experimental results on known mutants. The key residues and interaction fingerprints are furthermore used to predict if a novel sequence corresponds to a sod enzyme, and if so, what type of sod it is. The predictions of this fingerprint method reach much higher scores and present much more discriminative power than the commonly used method that uses pairwise sequence comparisons. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Differential native state ruggedness of the two Ca2+‐binding domains in a Ca2+ sensor protein
Authors: Krishna Mohan P. M. , Mukherjee Sulakshana , Chary Kandala V. R.
Published: October 2007

Characterization of near‐native excited states of a protein provides insights into various biological functions such as co‐operativity, protein–ligand, and protein–protein interactions. In the present study, we investigated the ruggedness of the native state of EhCaBP using nonlinear temperature dependence of backbone amide‐proton chemical shifts. EhCaBP is a two‐domain EF‐hand calcium sensor protein consisting of two EF‐hands in each domain and binds four Ca2+ ions. It has been observed that ∼30% of the residues in the protein access alternative conformations. Theoretical modeling suggested that these low‐energy excited states are within 2–3 kcal/mol from the native state. Further, it is interesting to note that the residues accessing alternative conformations are more dominated in the C‐terminal domain compared with its N‐terminal counterpart suggesting that the former is more rugged in its native state. These distinct characteristics of N‐ and C‐ terminal domains of a calcium sensor protein belonging to the super family of calmodulin would have implications for domain dependent Ca2+ signaling pathways. Proteins 2008. © 2007 Wiley‐Liss, Inc.
Response of the subterranean termite Coptotermes formosanus (Isoptera: Rhinotermitidae) to soil treated with microencapsulated fenobucarb
Authors: Kubota Shunichi , Shono Yoshinori , Matsunaga Tadahiro , Tsunoda Kunio
Published: October 2007

BACKGROUND: Treating soil with insecticides is thought to be an effective method for termite control. Speed of action and repellency of insecticides are important factors for discussing their barrier effects as soil‐treatment termiticides. The chemical barrier effect of microencapsulated fenobucarb against Coptotermes formosanus Shiraki was examined in the laboratory.

RESULTS: Fenobucarb had a significantly faster lethal effect when applied to the mouthparts than to the tergites of worker termites. Soil that had been treated with ≥ 50 mg kg−1 of microencapsulated fenobucarb had a barrier effect within a single day, and could stop or retard the penetration of termites for 7 days. Microencapsulated fenobucarb did not act as a repellent, as indicated by a gradual increase in mortality at ≥ 50 mg kg−1 with slight penetration into the treated soil during the 7 day test.

CONCLUSION: The results suggest that microencapsulated fenobucarb is a fast‐acting termiticide, with a good barrier effect as a soil treatment, that also acts as a reduced repellent, retarding entry of termites into treated soil. Copyright © 2007 Society of Chemical Industry
Antiphytoviral activity of bruceine‐D from Brucea javanica seeds
Authors: Shen Jian‐Guo , Zhang Zheng‐Kun , Wu Zu‐Jian , Ouyang Ming‐An , Xie Lian‐Hui , Lin Qi‐Ying
Published: October 2007

BACKGROUND: Brucea javanica (L.) Merr. is widely distributed throughout the southern parts of China and has been used in traditional medicine to treat a variety of diseases. The objective of the present study was to identify the active antiphytoviral compound in the seeds of B. javanica and evaluate the inhibitory activity of the compound against plant virus.

RESULTS: Bioassay‐guided fractionation of the most active extract from the seeds led to the isolation of an antiphytoviral compound which was identified as bruceine‐D by conventional spectroscopy methods. The compound exhibited significant inhibitory activity against the infection and replication of tobacco mosaic virus (TMV), with IC50 values of 13.98 and 7.13 mg L−1 respectively. The compound also showed a strong inhibitory effect on the infectivity of potato virus Y (PVY) and cucumber mosaic virus (CMV). Furthermore, the compound could effectively inhibit systemic TMV infection in the host tobacco plant under glasshouse conditions.

CONCLUSION: The results suggested that bruceine‐D from Brucea javanica may have the potential to be used as a natural viricide, or a lead compound for new viricides. Copyright © 2007 Society of Chemical Industry
The effect of methyl group on the cooperativity between three types of hydrogen bond: OH···O, CH···O, and OH···π
Authors: Li Qingzhong , An Xiulin , Luan Feng , Li Wenzou , Gong Baoan , Cheng Jianbo , Sun Jiazhong
Published: October 2007

The effect of the methyl group on the cooperativity between three types of hydrogen bond (OH···O, CH···O, and OH···π) in cyclic complex involving an acetylene and two waters has been studied on the basis of high‐level ab initio calculations. The total interaction energy of three hydrogen bonds increases as the number of methyl group in the complex increases. The binding distances of OH···π and OH···O hydrogen bonds shorten, while that of CH···O hydrogen bond elongates with increasing methyl group. This indicates that addition of methyl group leads to enhancement of OH···π and OH···O hydrogen bonds, and weakening of CH···O hydrogen bond, as also shown in frequency shift, chemical shifts, charge populations, and stabilization energies of orbital interactions. Although the presence of methyl group has a complicated effect on different type of hydrogen bond, the cooperativity of three hydrogen bonds increases in general with the addition of methyl group. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Hypermetabolism in Gaucher disease type I is not associated with altered thyroid hormone levels
Authors: Langeveld M. , Endert E. , Wiersinga W. M. , Aerts J. M. F. G. , Hollak C. E. M.
Published: October 2007

Type I Gaucher disease (OMIM 231000) is an inherited storage disorder in which deficiency of the enzyme glucocerebrosidase (EC 32145) leads to accumulation of glucocerebroside in lysosomes of macrophages. These storage cells are present in liver, spleen and bone marrow resulting in hepatosplenomegaly, cytopenia and bone complications. Metabolic abnormalities in Gaucher patients include hypermetabolism, possibly caused by elevated levels of pro‐inflammatory cytokines. Nonthyroidal illness (NTI) is a combination of changes in circulating thyroid hormone levels (decreased T3, elevated rT3, normal or mildly depressed TSH) present in different illnesses and might be an adaptation to protect the organism from harmful catabolic effects of hypermetabolism. The hypermetabolism and the elevated cytokine levels in Gaucher disease led us to hypothesize that the alterations in thyroid hormone levels as seen in NTI might also occur in Gaucher patients. We studied thyroid hormone levels before and during treatment in 22 adult type I Gaucher patients and resting energy expenditure (REE) and correlations with thyroid hormone levels in 12 patients. Baseline thyroid hormone levels were normal in the majority (17) of patients. No cases of nonthyroidal illness were detected. Baseline REE (kcal/kg per 24 h) was not correlated with circulating levels of T3, rT3 or fT4. Treatment of Gaucher disease with enzyme replacement therapy for several years resulted in a decrease in circulating fT4 levels. After several months of treatment most patients showed a decrease in REE. There was no correlation between the changes in REE and changes in fT4 and T3.
Soy‐Based Infant Formula Supplemented with DHA and ARA Supports Growth and Increases Circulating Levels of these Fatty Acids in Infants
Authors: Hoffman Dennis , Ziegler Ekhard , Mitmesser Susan H. , Harris Cheryl L. , Diersen‐Schade Deborah A.
Published: October 2007

Healthy term infants (n = 244) were randomized to receive: (1) control, soy‐based formula without supplementation or (2) docosahexaenoic acid−arachidonic acid (DHA + ARA), soy‐based formula supplemented with at least 17 mg DHA/100 kcal (from algal oil) and 34 mg ARA/100 kcal (from fungal oil) in a double‐blind, parallel group trial to evaluate safety, benefits, and growth from 14 to 120 days of age. Anthropometric measurements were taken at 14, 30, 60, 90, and 120 days of age and 24‐h dietary and tolerance recall were recorded at 30, 60, 90, and 120 days of age. Adverse events were recorded throughout the study. Blood samples were drawn from subsets of 25 infants in each group. Capillary column gas chromatography was used to analyze the percentages of fatty acids in red blood cell (RBC) lipids and plasma phospholipids. Compared with the control group, percentages of fatty acids such as DHA and ARA in total RBC and plasma phospholipids were significantly higher in infants in the DHA + ARA group at 120 days of age (P < 0.001). Growth rates did not differ significantly between feeding groups at any assessed time point. Supplementation did not affect the tolerance of formula or the incidence of adverse events. Feeding healthy term infants soy‐based formula supplemented with DHA and ARA from single cell oil sources at concentrations similar to human milk significantly increased circulating levels of DHA and ARA when compared with the control group. Both formulas supported normal growth and were well tolerated.
Visualization of maturation of the corpus callosum during childhood and adolescence using T2 relaxometry
Authors: Kim Eung Y. , Kim Dong‐Hyun , Yoo Eunhye , Park Hae‐Jeong , Golay Xavier , Lee Seung‐Koo , Kim Dong J. , Kim Jinna , Kim Dong I.
Published: October 2007

Previous studies have shown that maturation of the white matter in terms of its relative signal intensity changes on MRI is almost complete at 2–3 years of age. We hypothesized that quantitative analysis may show maturation of the white matter during childhood and adolescence. In the present study we performed multi‐echo T2 relaxometry in 33 healthy subjects (girls, 15; boys, 18) aged 3–15 years. T2 relaxation times of the genu and splenium were measured. In healthy subjects, the T2 relaxation times were significantly correlated with age in both girls (r = 0.611, p = .016) and boys (r = 0.721, p = .001) in the splenium, but not in the genu (p > .05). To further confirm genu‐to‐splenium signal intensity ratio changes, a total of 389 brain MRIs were retrospectively selected from the patients who had normal results (189 girls/women, 200 boys/men; age range, 3–20 years). The genu‐to‐splenium signal intensity ratio was obtained from the T2‐weighted images. In patients with normal MRI, the genu‐to‐splenium signal intensity ratio was significantly decreased with age (p < .001) by 16 years. The T2 relaxation times gradually increase in the splenium during childhood and adolescence, suggestive of maturation.
Social deficits in BTBR T + tf/J mice are unchanged by cross‐fostering with C57BL/6J mothers
Authors: Yang Mu , Zhodzishsky Vladimir , Crawley Jacqueline N.
Published: October 2007

Inbred strains of mice are useful model systems for studying the interactions of genetic and environmental contributions during neurodevelopmental stages. We recently reported an inbred strain, BTBR T + tf/J (BTBR), which, as compared to the commonly used C57BL/6J (B6) strain, displays lower social interactions as juveniles, lower social approach in adult ages, and higher levels of repetitive self‐grooming throughout developmental stages. The present study investigated whether the early postnatal maternal environment contributes substantially to the unusually low expression of social behaviors and high self‐grooming in BTBR as compared to B6. Within 24 h of birth, entire litters of pups were cross‐fostered to either a dam of the same strain or a dam of the opposite strain. Control litters were left with their own mothers. Offspring were tested for juvenile play at postnatal day 21 ± 1, for sociability at 8 weeks of age in an automated three‐chambered social approach test, and for self‐grooming at 9–11 weeks of age. Results indicate that deficits in play behaviors in juvenile BTBR pups were not rescued by a B6 maternal environment. Similarly, a BTBR maternal environment did not induce play deficits in B6 pups. Cross‐fostering had no effect on sociability scores in adults. The high self‐grooming in BTBR and low self‐grooming in B6 were not affected by maternal environment. These findings favor a genetic interpretation of the unusual social behaviors and self‐grooming traits of BTBR, and support the use of the BTBR inbred strain as a mouse model to study genetic mechanism of autism.
Expression of Concern: Long‐term outcomes of two different surgical techniques for cesarean
Authors: Nabhan A.F.
Published: October 2007

Objective

To assess the rate of adhesions and other long‐term outcomes of two cesarean delivery techniques.

Methods

A total of 600 women were randomly assigned to either a standard (Pfannenstiel–Kerr) or modified (Joel‐Cohen–Stark) technique for first‐time cesarean delivery. A total of 124 women were assessed at repeat cesarean delivery. The primary outcome measure was the presence of adhesions.

Results

At repeat cesarean delivery, anesthesia‐to‐delivery time, total duration of surgery, change in hemoglobin level, time to mobilization and oral intake, and postoperative hospital stay were significantly less with the modified technique. Adhesions were found in 7 (11.3%) and 22 (35.5%) of the cases using the modified and standard techniques, respectively (P = 0.0026; relative risk 3.14 [95% CI, 1.45–6.82]).

Conclusion

A modified cesarean delivery technique, including Joel‐Cohen incision, exteriorized full thickness suturing of the uterine incision, and non‐closure of the peritoneum may reduce long‐term morbidities of the procedure.
Measuring statistical agreement between four point of care (POC) lactate meters and a laboratory blood analyzer in cats
Authors: Acierno Mark J. , Johnson Meghan E. , Eddleman Lee Ann , Mitchell Mark A.
Published: October 2007

The use of blood lactate concentrations as a prognostic indicator and therapeutic gauge in feline medicine has been hindered by the inability to obtain values in a timely manner with minimal quantities of blood. Recently, hand-held point-of-care (POC) lactate meters have become commercially available. The objective of this prospective study was to determine if lactate values produced by three commercially available and one medical grade POC meter were in agreement with a laboratory blood analyzer. Blood samples from 47 cats were collected on presentation to an emergency service and processed on four POC meters and a Stat Profile Critical Care Xpress blood analyzer. The results were analyzed using the Bland–Altman method. The blood lactate values produced by the hospital grade POC meter and one of the commercially POC meters were in good agreement with the Critical Care Xpress blood analyzer. Other commercially available POC meters produced acceptable agreement.
Alkaline gabbroids of the Chirii outcrop (North Minusa depression): mineralogy and melt evolution
Authors: Timina T.Yu. , Sharygin V.V.
Published: October 2007

We studied the chemical composition of rock-forming minerals in gabbroids from the Chirii outcrop and the evolutionary features of parental basic melt during the crystallization of these rocks. Results were compared with data for basanites from pipes of the North Minusa depression. The mineralogical composition and thermobarogeochemical data of the gabbroids were examined in detail, and chemical analyses of rock-forming minerals (clinopyroxene, plagioclase, amphibole, biotite, titanomagnetite, and apatite) were carried out. Based on the homogenization temperatures of primary melt inclusions, we established the minimum temperatures and sequence of mineral crystallization in the gabbroids: clinopyroxene (>1160 °C), plagioclase, magnetite → amphibole (>950 °C) → biotite. The rock crystallization proceeded at shallow depths. Thermometric data are confirmed by results of modeling of equilibrium gabbroid crystallization. The crystallization of parental basic melt was accompanied by the accumulation of SiO2, Al2O3, alkalies, and Cl and depletion in femic components. The melt evolved to granodiorite and alkali-syenite compositions. Compared with basanites from pipes, the parental melt had a longer evolution. The geochemical features of the gabbroids indicate that they, like basanites, crystallized from intraplate alkali-basaltoid magmas. But in petrochemistry and mineralogy the Chirii gabbroids differ considerably from the pipe basanites.
Phase relationship and surface water mass change in the Northeast Atlantic during Marine Isotope Stage 11 (MIS 11)
Authors: Kandiano Evgeniya S. , Bauch Henning A.
Published: October 2007

Planktic foraminiferal census data, faunal sea surface temperatures (SSTs) and oxygen isotopic and lithic records from a site in the northeast Atlantic were analyzed to study the interglacial dynamics of Marine Isotope Stage (MIS) 11, a period thought to closely resemble the Holocene on the basis of orbital forcing. Interglacial conditions during MIS 11 persisted for approximately 26 ka. After the main deglacial meltwater processes ceased, a 10- to 12-ka-long transitional period marked by significant water mass circulation changes occurred before surface waters finally reached their thermal maximum. This SST peak occurred between 400 and 397 ka, inferred from the abundance of the most thermophilic foraminiferal species and was coincident with lowest sea level according to benthic isotope values. The ensuing stepwise SST decrease characterizes the overall climate deterioration preceding the increase in global ice volume by ∼ 3 ka. This cooling trend was followed by a more pronounced cold event that began at 388 ka, and that terminated in the recurrence of icebergs at the site around 382 ka. Because the water mass configuration of early MIS 11 evolved quite differently from that of the early Holocene, there is little evidence that MIS 11 can serve as an appropriate analogue for a future Holocene climate, despite the similarity in some orbital parameters.
Central issues in the residential care of young people
Authors: Coleman John C.
Published: October 2007

This paper is concerned with a number of important issues pertaining to the residential care of young people. Three different care settings for teenagers in the U.S.A. are briefly described with respect to their intake, treatment philosophy, physical setting and so on. The three are then compared according to the way in which the responsibility is shared between staff and adolescents, the sanction system is operated, limit‐testing behaviour is manifested and staff training is integrated into the life of the residential facility. It is argued that these structural features of residential care settings are of central importance, contributing far more to the success of the institution than such factors as the therapeutic orientation of the staff.
State Intervention and Vulnerable Children: Implementation Revisited
Authors: MURRAY CATHY
Published: October 2007

This article derives from a two year study of ‘Home Supervision’, conducted as part of a programme of research on the Children (Scotland) Act 1995. The focus is on children looked after by the local authority who are on a legal supervision order at home, primarily as a consequence of having been abused or neglected, having offended or having failed to attend school without reasonable excuse. Two assumptions, both arguably a legacy of Lipsky, are challenged: first, that non-implementation by street-level bureaucrats is in opposition to their managers; and, second, the passivity of clients in respect of policy making. It is argued that the street-level bureaucrats and managers in the Home Supervision study share assumptive worlds in respect of children on home supervision, and that clients, as agentic actors, reveal a capacity for shaping policy at the implementation stage. These issues are explored and their implications for implementation studies and child welfare are discussed.
Continuity and Change in the Korean Welfare Regime
Authors: ZOON HONG KYUNG , HO KEUN SONG
Published: October 2007

As a result of the consolidation of democracy and the spread of globalisation, the Korean welfare regime has undergone significant changes. This article examines the changes that have occurred since the 1990s. Overall social policy has benefited from a marked increase in expenditure since the 1990s. This has been especially visible in terms of the ratio of social expenditures to GDP, which reached 11 per cent by 1998. These changes in Korean social policy brought about a readjustment of the roles of both government and the private sector. The development of income maintenance programmes has been the core change within the Korean welfare regime. Unlike income maintenance programmes, public social services have developed at a rather sluggish pace. The provision of social services has long been regarded as the responsibility of the family and has changed relatively little in comparison to income maintenance programmes. Although Korean social policy has undergone remarkable changes, it would be erroneous to argue that a complete shift in the welfare regime has taken place.
Silicon supplementation and osteochondrotic lesions in 2-year-old Standardbreds: a preliminary study
Authors: Turner K K , Nielsen B D , O'Connor C I , Rosenstein D S
Published: October 2007

Silicon appears to be an essential element for proper endochondral ossification and glycosaminoglycan synthesis. Osteochondrosis (OC) is characterized by disturbed endochondral ossification, and glycosaminoglycan loss has been reported in OC lesions. Therefore, silicon may be effective in reducing OC lesions. The objective of the study was to evaluate the effects of supplemental silicon on OC lesion size. Initial radiographs were taken on 2-year-old Standardbreds (n = 44) on private facilities to identify OC defects in the distal third metacarpus/tarsus or osteochondral fragments at the dorsal aspect of the joint and defects/fragments at the distal tibia and on the trochlear ridges of the talus. Only clinically sound horses were included. Follow-up radiographs were taken at 120 days. Radiographs were digitized and the length and height of the OC defects/fragments were measured. Horses meeting study-inclusion requirements (n = 8) were pair-matched by facility and affected joint(s) and assigned to a group: control (receiving 200 g whole grain flour) and silicon supplemented (receiving 200 g bioavailable silicon source). Treatments were top-dressed on the feed for 120 days. Due to the onset of lameness, four horses did not complete the 120-day study duration. There was no effect (P>0.22) of treatment, time or treatment × time on lesion length, height or area. Silicon supplementation did not alter the radiographic appearance of OC lesions. Future research should focus on the effects of a silicon supplement on the prevention of OC lesions.
Two-dimensional kinematics of the jog and lope of the stock breed western pleasure horse
Authors: Nicodemus M C , Booker J E
Published: October 2007

Kinematic studies of western pleasure horses are limited and were performed before current changes in the stock breed association judging standards on the western pleasure gaits. The objective was to measure the kinematics of the jog and lope of the stock breed western pleasure horse. Reflective markers attached along palpation points of the joint centres of the left forelimb and hind limb of four stock breed western pleasure horses were tracked for five strides for each gait for each horse. Both the jog and lope were determined to be four-beat stepping gaits. During the jogging stance, the elbow (159.7 ± 6.6°), carpal (179.9 ± 1.1°), fore (227.6 ± 2.7°) and hind fetlocks (227.4 ± 6.9°), stifle (159.5 ± 6.5°) and tarsal (166.5 ± 6.5°) joints demonstrated peak extension. The same joints demonstrated during swing peak flexion with the hind fetlock joint having double peaks of flexion (195.7 ± 3.2°, 182.3 ± 2.1°). During loping stance, the elbow (153.4 ± 4.2°), carpal (179.7+0.4°), and fore (228.3 ± 9.7°, 229.8 ± 10.0°) and hind fetlock (232.1 ± 2.6°) joints of the leading limbs demonstrated peak extension with tarsal peak extension (157.0 ± 9.6°) occurring at lift-off. Peak flexion occurred during swing for the elbow (105.1 ± 3.1°), carpus (119.8 ± 6.1°), hip (83.5 ± 5.4°), stifle (129.8 ± 9.6°) and tarsus (127.5 ± 6.1°). Kinematic measurements will assist in objectively defining the stock breed western pleasure gaits.
Generation and Associative Encoding in Young and Old Adults
Authors: Taconnat Laurence , Froger Charlotte , Sacher Mathilde , Isingrini Michel
Published: October 2007

Abstract. The generation effect (i.e., better recall of the generated items than the read items) was investigated with a between-list design in young and elderly participants. The generation task difficulty was manipulated by varying the strength of association between cues and targets. Overall, strong associates were better recalled than weak associates. However, the results showed different generation effect patterns according to strength of association and age, with a greater generation effect for weak associates in younger adults only. These findings suggest that generating weak associates leads to more elaborated encoding, but that elderly adults cannot use this elaborated encoding as well as younger adults to recall the target words at test.
Size Doesn't Really Matter
Authors: Pulford Briony D. , Colman Andrew M.
Published: October 2007

Abstract. When attempting to draw a ball of a specified color either from an urn containing 50 red balls and 50 black balls or from an urn containing an unknown ratio of 100 red and black balls, a majority of decision makers prefer the known-risk urn, and this ambiguity aversion effect violates expected utility theory. In an experimental investigation of the effect of urn size on ambiguity aversion, 149 participants showed similar levels of aversion when choosing from urns containing 2, 10, or 100 balls. The occurrence of a substantial and significant ambiguity aversion effect even in the smallest urn suggests that influential theoretical interpretations of ambiguity aversion may need to be reconsidered.
O3‐N2O correlations from the Atmospheric Chemistry Experiment: Revisiting a diagnostic of transport and chemistry in the stratosphere
Authors: Hegglin Michaela I. , Shepherd Theodore G.
Published: October 2007

Our knowledge of stratospheric O3‐N2O correlations is extended, and their potential for model‐measurement comparison assessed, using data from the Atmospheric Chemistry Experiment (ACE) satellite and the Canadian Middle Atmosphere Model (CMAM). ACE provides the first comprehensive data set for the investigation of interhemispheric, interseasonal, and height‐resolved differences of the O3‐N2O correlation structure. By subsampling the CMAM data, the representativeness of the ACE data is evaluated. In the middle stratosphere, where the correlations are not compact and therefore mainly reflect the data sampling, joint probability density functions provide a detailed picture of key aspects of transport and mixing, but also trace polar ozone loss. CMAM captures these important features, but exhibits a displacement of the tropical pipe into the Southern Hemisphere (SH). Below about 21 km, the ACE data generally confirm the compactness of the correlations, although chemical ozone loss tends to destroy the compactness during late winter/spring, especially in the SH. This allows a quantitative comparison of the correlation slopes in the lower and lowermost stratosphere (LMS), which exhibit distinct seasonal cycles that reveal the different balances between diabatic descent and horizontal mixing in these two regions in the Northern Hemisphere (NH), reconciling differences found in aircraft measurements, and the strong role of chemical ozone loss in the SH. The seasonal cycles are qualitatively well reproduced by CMAM, although their amplitude is too weak in the NH LMS. The correlation slopes allow a “chemical” definition of the LMS, which is found to vary substantially in vertical extent with season.
Ultraviolet-oxidized mercaptan-terminated organosilane nanolayers as diffusion barriers at Cu-silica interfaces
Authors: Gandhi D. D. , Tisch U. , Singh B. , Eizenberg M. , Ramanath G.
Published: October 2007

We demonstrate the use of UV-exposed molecular nanolayers (MNLs) of 3-mercaptan-propyl-trimethoxysilane to inhibit copper-transport across Cu–SiO2 interfaces more efficiently than the pristine MNLs. Bias-thermal-annealing tests of Cu∕MNL∕SiO2∕Si(001)∕Al capacitors, with MNLs exposed to 254nm UV radiation, exhibit enhanced barrier properties to Cu diffusion, when compared with capacitors with MNLs not exposed to UV light. X-ray photoelectron spectroscopy reveals that UV exposure converts the mercaptan termini to sulfonates, which are more effective in inhibiting Cu diffusion. Our findings are of importance for tailoring the chemical and mechanical integrity of interfaces for use in applications such as nanodevice wiring and molecular electronics.
A priori analysis of the curvature and propagation terms of the flame surface density transport equation for large eddy simulation
Authors: Chakraborty Nilanjan , Cant R. S.
Published: October 2007

The statistical behavior of the propagation and curvature terms in the transport equation for flame surface density (FSD) is studied in the context of large eddy simulation (LES) of premixed combustion in the thin reaction zones regime. It is found that the propagation term is strongly influenced by curvature effects on displacement speed, and it is shown that the propagation term can be closed exactly without any additional modelling provided that the surface averaged displacement speed is accurately represented. The FSD curvature term is decomposed into resolved and subgrid contributions and three different model expressions for the resolved curvature term are studied. It is shown that the choice of expression for the resolved curvature term affects the modelling of the subgrid curvature term. This is important since the treatment of the subgrid curvature term involves the largest modelling uncertainties. Following this, it is argued that the most preferable expression for the resolved curvature term is the one which allows for the smallest subgrid contribution and which captures the correct trend of the complete LES-filtered curvature term. Predictions of existing models for the subgrid curvature term are assessed in comparison to values obtained from filtered direct numerical simulation data. It is demonstrated that the local curvature dependence of the LES surface averaged displacement speed plays a significant role in the modelling of both the curvature and propagation terms. A model is proposed which explicitly accounts for this dependence.
Laser induced Coulomb explosion and stimulated Raman scattering in cluster plasmas
Authors: Tiwari Pawan K. , Mok Chinook , Ryu Chang-Mo
Published: October 2007

Laser-driven Coulomb explosion can induce stimulated Raman scattering in cluster-embedded plasmas. The propagation and scattering of electromagnetic waves have been studied to show that Coulombic expansion of atomic clusters significantly modifies the scattering properties. When the cluster plasma collision is negligible, the cutoff frequency occurs due to the resonance, and this cutoff frequency is lowered as the cluster size increases. On the other hand, when there are collisions, the electron-ion collisions inhibit cluster electrons from absorbing laser energy resonantly, in which case the electromagnetic wave dispersion relation is not much affected by the presence of the cluster. Enhancement in the resonance absorption of laser energy is achieved when laser frequency becomes inversely proportional to the cubic root of the normalized cluster radius. The expansion of a dense cluster into the ambient plasma density is shown to accompany a swift decrease in the plasma wave frequency. The variation of the growth rate of the Raman backscattered wave with respect to the wave number, plasma density, and sizes of the clusters shows that, in a high-density cluster plasma, only long-wavelength modes survive until the end of the cluster expansion. The short wave scattering mode, which initially grows faster, quickly damps out in the early phase of the expansion.
The piezoresponse force microscopy of surface layers and thin films: Effective response and resolution function
Authors: Morozovska Anna N. , Eliseev Eugene A. , Kalinin Sergei V.
Published: October 2007

Signal formation mechanism in piezoresponse force microscopy (PFM) of piezoelectric surface layers and thin films on rigid and elastically matched substrates with different dielectric properties is analyzed and compared. This analysis provides the extension of recent studies of clamping effects in thin films in uniform fields [K. Lefki and G. J. M. Dormans, J. Appl. Phys. 76, 1764 (1994); L. Chen et al., J. Mater. Res. 19, 2853 (2004)] and in PFM in uniform materials [S. V. Kalinin et al., Phys. Rev. B 70, 184101 (2004); A. N. Morozovska et al., Phys. Rev. B 75, 174109 (2007)] to the case of PFM of thin films. Thickness dependence of effective piezoelectric response, object transfer function components, and Rayleigh two-point resolution are derived. Obtained exact series and simple Pade approximations can be applied for the effective piezoresponse analytical calculations in the case of films capped on various substrates. The effective piezoresponse is thickness dependent for films on substrates with low dielectric permittivity (extrinsic size effect), whereas the thickness dependence is essentially suppressed for giant permittivity or metallic substrates. The implications of analysis for ferroelectric data storage and device applications are discussed.
Modeling of screening effect on remote Coulomb scattering due to gate impurities by nonuniform free carriers in poly-Si gate
Authors: Ishihara Takamitsu , Koga Junji , Matsuzawa Kazuya , Takagi Shin-ichi
Published: October 2007

Remote Coulomb scattering due to gate impurities in poly-Si gate is examined by considering the screening effect due to free carriers in the poly-Si gate. A physics-based screening model, which enables inclusion of the nonuniform carrier distribution in the poly-Si gate into the evaluation of remote Coulomb scattering with high accuracy, is proposed. Based on the proposed screening model, the effect of the nonuniform carrier distribution in the poly-Si gate on the mobility limited by remote Coulomb scattering, μRCS, is quantitatively examined. It is shown that the screening model using the averaged carrier distribution in the poly-Si gate cannot provide the correct description of the behavior of μRCS and the inclusion of the nonuniformity of the carrier distribution is essential for the quantitative evaluation of μRCS.
Enhanced light emission from phosphorescent single-layered organic light-emitting devices doped with ionic salt by simultaneous thermal and electrical annealing
Authors: Oh Seung Seok , Park Jin Ho , Kim Sun Woong , Park Byoungchoo
Published: October 2007

We studied the effect of thermal and electrical annealing on the light emission of phosphorescent single-layered organic light-emitting devices (PHOLEDs) doped with ionic salt. From the annealed green PHOLEDs with only an Al cathode, we clearly observed homogeneous and enhanced electrophosphorescent emission over ∼50000cd∕m2. The efficiency of the device was also improved. The device operates at relatively low voltages and achieves a high peak current efficiency of over 30cd∕A, even at 1000cd∕m2. These improved characteristics regarding luminescence and efficiency indicate clearly that simultaneous annealing can induce proper adsorption of charged salt ions at the electrode surfaces. This adsorption will lead to an increased and balanced injection of carriers.
Direct imaging of quantum wires nucleated at diatomic steps
Authors: Molina S. I. , Varela M. , Sales D. L. , Ben T. , Pizarro J. , Galindo P. L. , Fuster D. , González Y. , González L. , Pennycook S. J.
Published: October 2007

Atomic steps at growth surfaces are important heterogeneous sources for nucleation of epitaxial nano-objects. In the presence of misfit strain, we show that the nucleation process takes place preferentially at the upper terrace of the step as a result of the local stress relaxation. Evidence for strain-induced nucleation comes from the direct observation by postgrowth, atomic resolution, Z-contrast imaging of an InAs-rich region in a nanowire located on the upper terrace surface of an interfacial diatomic step.
Optical coherence computed tomography
Authors: Li Li , Wang Lihong V.
Published: October 2007

A time-resolved optical tomography, optical coherence computed tomography, is proposed to bridge the gap between diffuse optical tomography and optical coherence tomography. Both ballistic and multiple-scattered photons are measured at multiple source-detection positions by low-coherence interferometry providing a temporal resolution smaller than 100fs. A light-tissue interaction model was established using the time-resolved Monte Carlo method. The optical properties were then reconstructed by solving the inverse transient radiative transport problem under the first Born approximation. Absorbing inclusions of 100μm diameter were imaged through a 2.6-mm-thick (∼30 scattering mean-free-paths) scattering medium.
A simple technique of enhancement of efficiency in optical frequency conversion
Authors: Das S. , Ghosh C. , Gangopadhyay S.
Published: October 2007

A simple technique for enhancement of conversion efficiency focusing by cylindrical lens of the interacting beams in three wave nonlinear interaction has been reported by generating second and third harmonics of 1064nm radiation in a Li2B4O7 crystal and compared the generated beam energy focusing by spherical lens. An increase in conversion efficiency of about 5.2 times has been realized in focusing by cylindrical lens than that in focusing by spherical lens.
Beryllium compensation doping of InAs∕GaSb infrared superlattice photodiodes
Authors: Hoffman Darin , Nguyen Binh-Minh , Delaunay Pierre-Yves , Hood Andrew , Razeghi Manijeh , Pellegrino Joe
Published: October 2007

Capacitance-voltage measurements in conjunction with dark current measurements on InAs∕GaSb long wavelength infrared superlattice photodiodes grown by molecular-beam epitaxy on GaSb substrates are reported. By varying the beryllium concentration in the InAs layer of the active region, the residually n-type superlattice is compensated to become slightly p type. By adjusting the doping, the dominant dark current mechanism can be varied from diffusion to Zener tunneling. Minimization of the dark current leads to an increase of the zero-bias differential resistance from less than 4to32Ωcm2 for a 100% cutoff of 12.05μm
Toward high-resolution prediction and design of transmembrane helical protein structures
Authors: Barth P. , Schonbrun J. , Baker D.
Published: September 2007

The prediction and design at the atomic level of membrane protein structures and interactions is a critical but unsolved challenge. To address this problem, we have developed an all-atom physical model that describes intraprotein and protein–solvent interactions in the membrane environment. We evaluated the ability of the model to recapitulate the energetics and structural specificities of polytopic membrane proteins by using a battery of
in silico
prediction and design tests. First, in side-chain packing and design tests, the model successfully predicts the side-chain conformations at 73% of nonexposed positions and the native amino acid identities at 34% of positions in naturally occurring membrane proteins. Second, the model predicts significant energy gaps between native and nonnative structures of transmembrane helical interfaces and polytopic membrane proteins. Third, distortions in transmembrane helices are successfully recapitulated in docking experiments by using fragments of ideal helices judiciously defined around helical kinks. Finally,
de novo
structure prediction reaches near-atomic accuracy (<2.5 Å) for several small membrane protein domains (<150 residues). The success of the model highlights the critical role of van der Waals and hydrogen-bonding interactions in the stability and structural specificity of membrane protein structures and sets the stage for the high-resolution prediction and design of complex membrane protein architectures.