bluuebunny/crossref_metadata_2025 huggingface dataset:
A generic complete dynamic logic for reasoning about purity and effects
Authors: Mossakowski Till , Schröder Lutz , Goncharov Sergey
Published: April 2010

For a number of programming languages, among them Eiffel, C, Java, and Ruby, Hoare-style logics and dynamic logics have been developed. In these logics, pre- and postconditions are typically formulated using potentially effectful programs. In order to ensure that these pre- and postconditions behave like logical formulae (that is, enjoy some kind of referential transparency), a notion of purity is needed. Here, we introduce a generic framework for reasoning about purity and effects. Effects are modelled abstractly and axiomatically, using Moggi’s idea of encapsulation of effects as monads. We introduce a dynamic logic (from which, as usual, a Hoare logic can be derived) whose logical formulae are pure programs in a strong sense. We formulate a set of proof rules for this logic, and prove it to be complete with respect to a categorical semantics. Using dynamic logic, we then develop a relaxed notion of purity which allows for observationally neutral effects such writing on newly allocated memory.
Has the Accuracy of Preoperative Diagnosis Improved in Cases of Early‐stage Gastric Cancer?
Authors: Tsujimoto Hironori , Sugasawa Hidekazu , Ono Satoshi , Ichikura Takashi , Yamamoto Junji , Hase Kazuo
Published: April 2010

Background

Adequate preoperative evaluation for gastric cancer staging is essential to develop an individualized treatment strategy involving surgery with reduced lymphadenectomy and laparoscopic gastrectomy.

Methods

A total of 509 gastric cancer patients with clinical Stage IA or IB disease were divided into two groups: 304 patients were admitted in 2000 or earlier (Group A), and 205 patients were admitted in 2001, when multidetector computed tomography (MD‐CT) was available, or later (Group B). We evaluated the accuracy of the preoperative diagnoses of tumor depth, lymph node involvement, and tumor stage.

Results

With respect to tumor depth, 94.5 and 52.8% of patients were staged correctly in cT1 and cT2 patients, respectively. Among both cT1 and cT2 patients, the underestimated rates were lower in Group B than in Group A. For nodal metastasis, 83.2 and 30.0% of patients were staged correctly in cN0 and cN1 patients, respectively. Among the cN0 patients, 82.1 and 84.7% of Group A and Group B patients, respectively, were staged correctly. Among the cN1 patients, none of the patients in Group B was underestimated, while 9.7% of Group A patients were underestimated. There was a significant increase in the percentage of correctly staged patients and a decrease in the percentage of underestimated patients in Group B in comparison to Group A in both cStage IA and cStage IB patients.

Conclusions

Remarkable advances have been observed in the accuracy of preoperative staging in the early stage of gastric cancer. However, it is necessary to continue to develop accurate preoperative and intraoperative diagnostic systems.
Impact of the Introduction of Laparoscopic Wedge Resection as a Surgical Option for Suspected Small/Medium‐Sized Gastrointestinal Stromal Tumors of the Stomach on Perioperative and Oncologic Outcomes
Authors: Goh Brian K. P. , Chow Pierce K. H. , Chok Aik‐Yong , Chan Weng‐Hoong , Chung Yaw‐Fui A. , Ong Hock‐Soo , Wong Wai‐Keong
Published: April 2010

Background

The present study is designed to determine the feasibility and impact of the introduction of laparoscopic wedge resection as a surgical option for the treatment of suspected small/medium‐sized (<7 cm) gastric gastrointestinal stromal tumors (GISTs).

Methods

The study involved a retrospective review of 53 consecutive patients who underwent laparoscopic or open wedge resection of a suspected gastric GIST. It was divided into two consecutive time periods wherein laparoscopic resection was a surgical option only in the latter period. Comparisons were made between the outcomes of patients who underwent laparoscopic versus open wedge resection and the outcomes of patients treated during the two consecutive time periods (to determine the impact of the introduction of laparoscopic wedge resection),

Results

Fourteen patients (26%) underwent laparoscopic wedge resection with 1 conversion. The pathological exam showed that 41 patients (77%) had a GIST. Laparoscopic resection was significantly associated with a longer operative time, an earlier return of bowel function, earlier resumption of liquid and solid diet, decreased duration of parenteral or epidural analgesia use, and shorter postoperative hospitalization compared to open resection. There was no statistical difference in the rate of R1 resection and actuarial recurrence‐free survival for the two approaches. Comparison between the two time periods demonstrated that the introduction of the laparoscopic approach in the latter period resulted in an earlier return of bowel function, earlier resumption of liquid and solid diet, and decreased duration of parenteral or epidural analgesia.

Conclusions

Laparoscopic wedge resection for gastric GIST can be safely adopted. It is associated with a more favorable perioperative outcome than the open approach. Its introduction as a surgical option has resulted in an improvement in perioperative outcomes without compromising oncologic safety at our institution.
Comparing Hepatic Resection and Transarterial Chemoembolization for Barcelona Clinic Liver Cancer (BCLC) Stage B Hepatocellular Carcinoma: Change for Treatment of Choice?
Authors: Lin Chin‐Ta , Hsu Kuo‐Feng , Chen Teng‐Wei , Yu Jyh‐Cherng , Chan De‐Chuan , Yu Chih‐Yung , Hsieh Tsai‐Yuan , Fan Hsiu‐Lung , Kuo Shih‐Ming , Chung Kuo‐Piao , Hsieh Chung‐Bao
Published: April 2010

Background

Compared to transarterial chemoembolization (TACE) for patients with hepatocellular carcinoma (HCC), stage B in the Barcelona Clinic Liver Cancer (BCLC) classification, the role of hepatic resection remains unclear. The present study compared the long‐term outcome of hepatic resection with TACE in the treatment of BCLC stage B HCC.

Methods

A total of 171 patients with BCLC stage B, Child’s classification A (Child A), HCC were included in this retrospective study. Of these, 93 patients underwent hepatic resection (group I) and 73 patients received TACE (group II). We evaluated the long‐term outcome and therapy‐related mortality in both groups. The risk factors of mortality were assessed. The survival curve was analyzed by the Kaplan–Meier method.

Results

The 1‐, 2‐, and 3‐year overall survival rates for the two groups after hepatic resection and TACE were 83%, 62%, 49% and 39%, 5%, 2%, respectively (P < 0.0001). We did not observe significant differences in the therapy‐related mortality between the two groups (P = 0.78). Treatment modality and serum albumin level were independent risk factors for survival by Cox regression analysis.

Conclusions

Our study demonstrated that hepatic resection for BCLC stage B, Child A HCC patients had better survival rates than TACE group. Thus, hepatic resection is indicated in selected patients with BCLC stage B.
How to measure the urban‐wildland ecotone: redefining ‘peri‐urban’ areas
Authors: MacGregor‐Fors Ian
Published: April 2010

The array of definitions regarding ‘peri‐urban’ areas do not allow the precise measurement of its boundaries in a city. In this study, I developed an easy‐to‐use method to calculate the area where urban and adjacent non‐urban systems intermingle. To validate that such areas were ecologically meaningful, I compared bird community species‐richness, abundance, and composition from ‘intra‐’ and ‘peri‐urban’ areas in a medium‐sized neotropical city. Results show that ‘peri‐urban’ areas represent an important ecological interaction area for birds, and differ greatly from ‘intra‐urban’ areas. The proposed method is robust and useful for a great variety of amoeboid‐growing cities.
Nested Logit Models for Multiple-Choice Item Response Data
Authors: Suh Youngsuk , Bolt Daniel M.
Published: April 2010

Nested logit item response models for multiple-choice data are presented. Relative to previous models, the new models are suggested to provide a better approximation to multiple-choice items where the application of a solution strategy precedes consideration of response options. In practice, the models also accommodate collapsibility across all distractor categories, making it easier to allow decisions about including distractor information to occur on an item-by-item or application-by-application basis without altering the statistical form of the correct response curves. Marginal maximum likelihood estimation algorithms for the models are presented along with simulation and real data analyses.
A senescence accelerated mouse model to study aging in the larynx
Authors: Kolachala Vasantha L. , Torres‐Gonzalez Edilson , Mwangi Simon , Kelly Patricia , Brigham Kenneth L. , Pavlath Grace K. , Rojas Mauricio , Johns Michael M.
Published: April 2010

Objective

Age‐related changes in the larynx lead to significant voice impairment and reduced quality of life. There is a need for aged animal models that have practical generation times to study the fundamental changes and new therapeutics for the aging voice. The senescence accelerated prone mouse strain (SAMP) animals experience rapid aging without any experimental manipulation. The main objective of this study was to demonstrate the use of senescence accelerated mice to study aging in the larynx.

Study Design

Murine model.

Setting

Department of Animal Resources, Emory University.

Subjects and Methods

Larynges from five senescence accelerated prone mice, five normal aging senescence resistant mice, and five C57BL/6 mice were harvested and processed for paraffin sections. Histomorphometry was performed for assessment of collagen and hyaluronic acid distribution. In addition, frozen laryngeal tissue was harvested for transcriptional and translational assessment of collagen‐1, using real‐time polymerase chain reaction with specific primers and Western blots. Myofibroblast assessment was performed by immunostaining for the presence of α‐smooth muscle actin.

Results

The deposition of collagen increased at six months of age in the SAMP vocal fold, and the level of collagen‐1 mRNA increased with age. The myofibroblast protein α‐smooth muscle actin was also found at a higher concentration in the SAMP vocal tissue. In contrast, the levels of hyaluronic acid in the vocal folds of SAMP mice decreased with age when compared to age‐matched C57BL/6 mice.

Conclusion

SAMP mice show accelerated, age‐related changes in the vocal fold that were evident at as early as six months of age. The use of senescence accelerated mice offers promise as a model to study age‐related laryngeal changes.
Drest in a little brief authority: Controls in residential work with adolescents
Authors: Lampen John
Published: April 2010

I have suggested that in residential work with adolescents anxiety about controls is sometimes excessive, but given a pseudo‐justification by invoking parental models. A clearer understanding of the variety of parental tasks might help to reduce this anxiety. In the residential setting, however, the adults have other tasks, which include removing the obstacles to the emergence of a healthy moral consensus, the explicit and implicit expression of this consensus to which both they and the youngsters can contribute, the embodiment of a caring philosophy with which the youngsters can identify; and the encouragement of eventual independence, self‐control, and responsibility for others.
A new genus of Phyllobothriidae (Cestoda: Tetraphyllidea) in carcharhiniform sharks from Iran and Australia
Authors: Caira J.N. , Malek M. , Ruhnke T.
Published: April 2010

The collection of cestodes from the carcharhiniform shark Carcharhinus cf. dussumieri in the Persian Gulf off Iran resulted in the discovery of the new genus and species of tetraphyllidean tapeworm, Doliobothrium haselii n. gen. n. sp. Collections from the carcharhiniform shark Rhizoprionodon acutus in the Timor Sea off northern Australia resulted in material that is consistent with a species originally described as Pithophorus musculosus from this host species in India, but that appears to represent a second species in the new genus. This second species is redescribed and transferred to Doliobothrium n. gen. The two species differ from one another in total length, testis number and total number of proglottids, with the latter species generally being smaller in overall size than the former species. Histological sections and scanning electron microscopy confirm that this new genus differs from all other phyllobothriid genera in the possession of bothridia that both lack apical suckers and are tubular in form, bearing proximal and distal apertures. Despite differences in scolex morphology, the proglottids of the new genus are remarkably similar to those seen in Orectolobicestus, Paraorygmatobothrium and Ruhnkecestus, all of which also parasitize sharks. These four genera also share the presence of serrate gladiate spinitriches on their proximal bothridial surfaces. This is only the second report of a cestode from an elasmobranch from the Persian Gulf. Limited available data suggest that the fauna of this region resembles that of other regions of the Indo-Pacific. Furthermore, owing to the paucity of available information and specimens, it is recommended that Pithophorus and three of its remaining described species (i.e. P. pakistanensis, P. trygoni, P. yamagutii) be considered as a genus inquirendum and species inquirenda, respectively.
Comparison between cartilage–perichondrium composite ‘ring’ graft and temporalis fascia in type one tympanoplasty in children
Authors: Albirmawy O A
Published: April 2010

Objective:

This study aimed to evaluate the anatomical and audiological outcomes of primary type one tympanoplasty performed with a modified cartilage–perichondrium composite ‘ring’ graft, and to compare them with results for primary type one tympanoplasty performed with temporalis fascia, in children.

Study design:

Retrospective clinical study.

Setting:

Otolaryngology department, Tanta University Hospital, Egypt.

Patients and methods:

Records were evaluated for 82 children with dry tympanic membrane perforation (any size) and intact ossicular chain, and with no history of previous ear surgery except for tympanostomy. Patients of similar age and middle-ear pathology were selected to make the two groups as homogeneous as possible. An underlay type one tympanoplasty, using either a ring graft or temporalis fascia, was performed: 40 children were included in the ring graft group and 42 in the temporalis fascia group. All procedures were performed by the same surgeon. A successful anatomical outcome was considered to comprise full, intact healing of the graft without perforation, retraction, lateralisation or blunting, for at least one year post-operatively. Patients' post-operative pure tone average air–bone gap and speech reception threshold were compared with pre-operative levels, within and between the two groups.

Results:

Type one tympanoplasty using a ring graft technique resulted in a significantly greater graft acceptance rate (95 per cent) compared with the temporalis fascia technique (76.2 per cent;p < 0.01). Pure tone average air–bone gap and speech reception threshold levels improved significantly in both the ring graft and fascia groups (p < 0.001). There was no significant difference in audiometric results between the two groups (p > 0.05), although there was a trend towards better post-operative results in the ring group.

Conclusion:

In our paediatric patients, type one tympanoplasty with a modified cartilage–perichondrium composite ring graft yielded good anatomical and functional results. The anatomical results obtained using this graft (with its unique appearance and stability during and after surgery) were superior to those for temporalis fascia. The ring graft group had equivalent, if not better, post-operative audiometric results, compared with the temporalis fascia group. Thus, the ring graft is believed to be effective in enabling both tympanic membrane closure and rapid hearing improvement, in the paediatric population.
Influence of substratum colour on the recruitment of macrofouling communities
Authors: Satheesh S. , Wesley S. Godwin
Published: April 2010

Settlement of the fouling community is generally influenced by the physical, chemical and biological properties of the settling surface. The colour of the substratum may also exert an influence on larval settlement. In the present study, the influence of surface colour on the recruitment of fouling communities was investigated by suspending acrylic panels (red, green, blue, white and yellow) in coastal waters. Results showed that the colour of the substratum plays an important role in the recruitment of sessile species. Recruitment was comparatively high on red and blue coloured surfaces. Barnacle and tubeworm recruitment showed significant variation (Tukey test, P < 0.05) between different coloured surfaces. The significant conclusion of this study is that the colour of the artificial substrata should be taken into consideration when interpreting results from short-term biofouling studies.
Tidal-amplitude rhythms of larval release: variable departure from presumed optimal timing among populations of the mottled shore crab
Authors: Bueno M. , Flores A.A.V.
Published: April 2010

It is widely assumed that optimal timing of larval release is of major importance to offspring survival, but the extent to which environmental factors entrain synchronous reproductive rhythms in natural populations is not well known. We sampled the broods of ovigerous females of the common shore crab Pachygrapsus transversus at both sheltered and exposed rocky shores interspersed along a 50-km coastline, during four different periods, to better assess inter-population differences of larval release timing and to test for the effect of wave action. Shore-specific patterns were consistent through time. Maximum release fell within 1 day around syzygies on all shores, which matched dates of maximum tidal amplitude. Within this very narrow range, populations at exposed shores anticipated hatching compared to those at sheltered areas, possibly due to mechanical stimulation by wave action. Average departures from syzygial release ranged consistently among shores from 2.4 to 3.3 days, but in this case we found no evidence for the effect of wave exposure. Therefore, processes varying at the scale of a few kilometres affect the precision of semilunar timing and may produce differences in the survival of recently hatched larvae. Understanding the underlying mechanisms causing departures from presumed optimal release timing is thus important for a more comprehensive evaluation of reproductive success of invertebrate populations.
Stratification of the top of the core due to chemical interactions with the mantle
Authors: Buffett Bruce A. , Seagle Christopher T.
Published: April 2010

Chemical interactions between the core and the mantle have been proposed as a mechanism to transfer O and Si to the core. Adding light elements to the top of the core creates a stratified layer, which grows by chemical diffusion into the underlying convecting region. We develop a physical model to describe the evolution of the layer and estimate physical properties to aid in its detection. The interface between the stratified layer and the convecting interior is defined by the onset of double diffusive instabilities. Oscillatory instabilities arise from the interplay of a stable compositional stratification and an unstable thermal stratification due to a superadiabatic heat flow at the core‐mantle boundary. Double diffusive convection in the region of neutral stratification establishes the base of the layer and sets the rate of entrainment of excess light element into the interior of the core. Growth of the layer by diffusion is interrupted by nucleation of the inner core, which segregates light elements into the convecting part of the core. For calculations using O as the sole light element, we find that the base of the stratified layer retreats toward the core‐mantle boundary as the radius of the inner core increases. Representative (but uncertain) model parameters yield a present‐day layer thickness of 60 to 70 km. We also calculate the anomaly in P wave velocity relative to the value for a well‐mixed core. The velocity anomaly decreases almost linearly across the layer with a peak value of 2% at the core‐mantle boundary. This anomaly should be large enough to detect in seismic observations, although the sign of the anomaly is opposite to estimates obtained in previous seismic studies. We suggest possible explanations for this discrepancy and speculate about the implications for the structure of the Earth's interior.
Ensemble‐based simultaneous state and parameter estimation for treatment of mesoscale model error: A real‐data study
Authors: Hu Xiao‐Ming , Zhang Fuqing , Nielsen‐Gammon John W.
Published: April 2010

This study explores the treatment of model error and uncertainties through simultaneous state and parameter estimation (SSPE) with an ensemble Kalman filter (EnKF) in the simulation of a 2006 air pollution event over the greater Houston area during the Second Texas Air Quality Study (TexAQS‐II). Two parameters in the atmospheric boundary layer parameterization associated with large model sensitivities are combined with standard prognostic variables in an augmented state vector to be continuously updated through assimilation of wind profiler observations. It is found that forecasts of the atmosphere with EnKF/SSPE are markedly improved over experiments with no state and/or parameter estimation. More specifically, the EnKF/SSPE is shown to help alleviate a near‐surface cold bias and to alter the momentum mixing in the boundary layer to produce more realistic wind profiles.
T-cell receptor early signalling complex activation in response to interferon-α receptor stimulation
Authors: Stevens Claire N. , Simeone Ann-Marie , John Susan , Ahmed Zamal , Lucherini Orso M. , Baldari C. Tatiana , Ladbury John E.
Published: April 2010

Signalling through the IFNαR (interferon-α receptor) and TCR (T-cell receptor) in Jurkat T lymphocytes results in distinct immune responses. Despite this both receptors elicit ERK (extracellular-signal-regulated kinase)/MAPK (mitogen-activated protein kinase) phosphorylation. Vav and Slp76 are shown to be required for IFNα (interferon-α)-stimulated ERK activity. These form a subset of proteins which behave identically on stimulation of both receptors. TCR deletion abrogates IFNαR-stimulated MAPK activity, whereas the canonical JAK/STAT (Janus kinase/signal transducer and activator of transcription) pathway is unaffected. Thus recruitment of the intact TCR ESC (early signalling complex) is necessary for this downstream MAPK response. Despite using a common ESC, stimulation of the IFNαR does not produce the transcriptional response associated with TCR. Up-regulation of the MAPK pathway by IFNαR might be important to ensure that the cell responds to only one stimulant.
Molecular determinants of transient and reversible induced up-regulation ofCaCDR1in azole susceptible clinical isolates ofCandida albicans
Authors: Manoharlal Raman , Sharma Monika , Prasad Rajendra
Published: April 2010

The present study examines the molecular mechanism underlying in vitro-induced resistance to FLC (fluconazole), KTC (ketaonazole), MCZ (miconazole) and CHX (cycloheximide) in AS (azole-susceptible) strains of Candida albicans when exposed to CaCDR1/CaCDR2 inducers like FPZ (fluphenazine) and steroids [PRG (progesterone) and β-EST (β-oestradiol)]. By employing spot and checkerboard titre assays, we provide evidence of an in vitro-induced antagonism between tested drugs and inducers, which was accompanied with a concomitant increase in CaCDR1 and CaCDR2 transcript levels. Notably, unlike AS isolates, parental WT (wild-type) and Δcdr2 null strains, Δcdr1 as well as Δcdr1/Δcdr2 nulls, when challenged with the inducers could not display antagonism. Our results validated by Northern blotting, reporter gene transcription and TRO (transcription run on) assays show that in vitro-induced antagonism between tested drugs and inducer in AS isolates was mainly due to a transient and reversible transcriptional activation of CaCDR1. Notwithstanding our earlier observation that consistent high transcript levels of CaCDR1 in clinical AR (azole-resistant) isolates were maintained due to the combination of its transcriptional activation and enhanced mRNA stability via elongated poly(A) tails, this study shows that transient and reversible transcriptional activation of CaCDR1 was the major determinant of induced antagonism in AS isolates. The distinct strategies between sustained (in AR isolates) and transiently induced resistance mechanisms (in AS isolates) adopted by Candida should become useful in improving therapeutic approaches.
K48‐ and K63‐linked polyubiquitination of deubiquitinating enzyme USP44
Authors: Suresh Bharathi , Ramakrishna Suresh , Lee Hey‐Jin , Choi Jong‐Ho , Kim Jin‐Young , Ahn Woong‐Shick , Baek Kwang‐Hyun
Published: April 2010

Ubiquitination and deubiquitination have a critical role in protein homoeostasis in the cell. Here, we have characterized a novel USP44 (ubiquitin‐specific protease 44), which has a ZnF‐UBP (zinc‐finger ubiquitin‐specific protease) domain and conserved cysteine, histidine and asparagine/aspartic acid residues characteristic of deubiquitinating enzymes. The biochemical assay revealed that USP44 can cleave ubiquitin from ubiquitinated substrates both in vitro and in vivo. Further, USP44 undergoes both lysine 48‐ and lysine 63‐linked polyubiquitination. In situ hybridization using mouse tissues showed a basal detection level in all organs tested, with strong detection in lung, pancreas, skin, liver, stomach and intestine. RT‐PCR (reverse‐transcription PCR) analysis showed high levels of detection of USP44 mRNA in testis, spleen, lung, stomach and ovary. Furthermore, we raised a polyclonal antibody against USP44 and checked its endogenous protein expression in different cell lines. A localization study of USP44 showed its predominant expression in the nucleus.
CD45+/CD133+ positive cells expanded from umbilical cord blood expressing PDX‐1 and markers of pluripotency
Authors: Pessina Augusto , Bonomi Arianna , Sisto Francesca , Baglio Carolina , Cavicchini Loredana , Ciusani Emilio , Coccé Valentina , Gribaldo Laura
Published: April 2010

UCB (human umbilical cord blood) contains cells able to differentiate into non‐haematopoietic cell lineages. It also contains cells similar to primitive ESCs (embryonic stem cells) that can differentiate into pancreatic‐like cells. However, few data have been reported regarding the possibility of expanding these cells or the differential gene expression occurring in vitro. In this study, we expanded formerly frozen UCB cells by treatment with SCF (stem cell factor) and GM‐CSF (granulocyte–macrophage colony stimulating factor) in the presence of VPA (valproic acid). Gene expression profiles for beta cell differentiation and pluripotency (embryo stem cell phenotype) were analysed by RT‐PCR and immunocytochemistry. The results show a dramatic expansion (>150‐fold) of haematopoietic progenitors (CD45+/CD133+) which also expressed embryo markers of pluripotency (nanog, kfl‐4, sox‐2, oct‐3/4 andc‐myc), nestin, and pancreatic markers such as pax‐4, ngn‐3, pdx‐1 and syt‐1 (that is regulated by pdx‐1 and provides the cells with a Ca++ regulation mechanism essential for insulin exocytosis). Our results show that UCB cells can be expanded to produce large numbers of cells of haematopoietic lineage that naturally (without the need of retroviral vectors or transposons) express a gene pattern compatible with endocrine pancreatic precursors and markers of pluripotency. Further investigations are necessary to clarify, first, whether in this context, the embryogenes expressed are functional or not, and secondly, since these cells are safer than cells transfected with retroviral vectors or transposons, whether they would represent a potential tool for clinical application.
Purification and characterization of the plasmodial phosphatase that hydrolyses the phosphorylated light chain ofPhysarummyosin II fromPhysarum polycephalum
Authors: Okada Chisa , Nakamura Akio , Tomioka Shigeo , Kohama Kazuhiro , Kaneko Takako S.
Published: April 2010

A phosphatase was purified through a combination of ion‐exchange and hydrophobic chromatography followed by native PAGE fromPhysarumplasmodia. Recently, we demonstrated that this phosphatase isoform has a hydrolytic activity towards the PMLC (phosphorylated light chain ofPhysarummyosin II) at pH 7.6. The apparent molecular mass of the purified enzyme was estimated at approximately 50 kDa by means of analytical gel filtration. The enzyme was purified 340‐fold to a final phosphatase activity of 400 pkat/mg of protein. Among the phosphorylated compounds tested for hydrolytic activity at pH 7.6, the enzyme showed no activity towards nucleotides. At pH 7.6, hydrolytic activity of the enzyme against PMLC was detected; at pH 5.0, however, no hydrolytic activity towards PMLC was observed. TheKmof the enzyme for PMLC was 10 μM, and theVmaxwas 1.17 nkat/mg of protein. Ca2+(10 μM) inhibited the activity of the enzyme, and Mg2+(8.5 μM) activated the dephosphorylation of PMLC. Mn2+(1.6 μM) highly stimulated the enzyme's activity. Based on these results, we concluded that the enzyme is likely to be a phosphatase with hydrolytic activity towards PMLC.
In vitro differentiation of human amniotic fluid‐derived cells: Augmentation towards a neuronal dopaminergic phenotype
Authors: Pfeiffer Shona , McLaughlin David
Published: April 2010

Amniotic fluid is known to yield a number of cell types which are multipotent, ethically derived, genetically stable, easily grown, expanded and possess favourable immunogenicity, which has resulted in an increasing interest for use in various neuronal disorders such as Parkinson's disease. The neuronal potential of cells derived from the adherent fraction of amniotic fluid, routinely taken by amniocentesis, are least explored. The aim of the present study was to investigate the capacity of these cells for neuronal and dopaminergic differentiation using in vitro differentiation protocols with canonical inductive factors not previously tested. To do this, samples derived from multiple donors were grown under four conditions: standard serum‐containing media, NB (neurobasal) media designed specifically for propagation and maintenance of neuronal cells, NB media with addition of retinoic acid and BDNF (brain‐derived neurotrophic factor) for NI (neuronal induction), and NB media with addition of FGF8 (fibroblast growth factor‐8) and Shh (sonic hedgehog) after NI. Our results showed the presence of multiple neuronal markers after growth in serum‐containing medium [TUJ1, MAP2, NF‐M, TH (tyrosine hydroxylase)], which was significantly up‐regulated after serum withdrawal in NB medium alone with induction of NeuN (neuronal nuclei) and NSE (neuron‐specific enolase). NI and DA.I (dopaminergic induction) was accompanied by further increases in expression and a distinct transition to a sustained neuronal morphology. Western blot analysis confirmed increasing TH expression and NURR1, expressed in base serum‐containing media, found to be down‐regulated after induction. In conclusion, these cells possess a highly favourable base neuronal and dopaminergic prepotential, which may easily be accentuated by standard induction protocols.
Regulation in chronic obstructive pulmonary disease: the role of regulatory T-cells and Th17 cells
Authors: Lane Nina , Robins R. Adrian , Corne Jonathan , Fairclough Lucy
Published: April 2010

COPD (chronic obstructive pulmonary disease) is an inflammatory disorder of the airways, which is associated with irreversible airway obstruction. The pathological hallmarks of COPD are destruction of the lung parenchyma (pulmonary emphysema), inflammation of the central airways (chronic bronchitis) and inflammation of the peripheral airways (respiratory bronchiolitis). Tobacco smoking is established as the main aetiological factor for COPD. A maladaptive modulation of inflammatory responses to inhalation of noxious particles and gases is generally accepted as being a key central pathogenic process; however, the precise regulatory mechanisms of the disease are poorly understood. Two cell types are known to be important in immune regulation, namely regulatory T-cells and the newly identified Th17 (T-helper 17) cells. Both types of cells are subsets of CD4 T-lymphocytes and modulate the immune response through secretion of cytokines, for example IL (interleukin)-10 and IL-17 respectively. The present review will begin by describing the current understanding of inflammatory cell involvement in the disease process, and then focus on the possible role of subsets of regulatory and helper T-cells in COPD.
Measure of precursor electron density profiles of laser launched radiative shocks
Authors: Busquet Michel , Thais Frédéric , González Matthias , Audit Edouard
Published: April 2010

We have studied the dynamics of strong radiative shocks generated with the high-energy subnanosecond iodine laser at Prague Asterix Laser System facility (Prague) over long time scales, up to 100 ns. These shock waves are characterized by a developed radiative precursor, a radiation driven ionization wave in front of the density jump of the shock. Electronic density profiles are measured at different times after the laser pulse and at different distances from the axis of the shock tube. A new feature, described as a split precursor, has been observed. Comparisons with two-dimensional computations are shown.
Magnetoresistance effect in soft magnetic amorphous microwires
Authors: Óvári T.-A. , Grigoraş M. , Chiriac H.
Published: April 2010

Results on the magnetoresistance (MR) effect in Co-based amorphous glass-coated microwires with nearly zero magnetostriction and no granular structure are reported. MR measurements have been performed in parallel and perpendicular configurations, in both low field and high field regimes. The results show that high field resistance variations are caused by the corresponding magnetization processes in both parallel and perpendicular configurations. In case of low parallel field, no resistance variation has been emphasized. A sharp MR response was observed in case of a perpendicularly applied low field and it was attributed to the interdomain wall between the inner core and the outer shell of such microwires. The sharpness of the low field MR peak can be controlled through the microwire dimensions. The results bring new information about the domain structure of amorphous microwires and open up new application opportunities for these materials.
High magnetization aqueous ferrofluid: A simple one-pot synthesis
Authors: Carroll Kyler J. , Shultz Michael D. , Fatouros Panos P. , Carpenter Everett E.
Published: April 2010

A one-step polyol method was utilized to prepare a stable aqueous iron/iron oxide ferrofluid. The dried powders were characterized by x-ray diffraction, electron microscopy, x-ray absorption spectroscopy, and vibrating sample magnetometry for the determination of phase, morphology, and magnetic properties. To show its potential for imaging applications, the ferrofluid was also investigated as a magnetic resonance imaging contrast agent.
Microscopic origins of the ferromagnetic exchange coupling in oxoverdazyl-based Cu(II) complex
Authors: Rota Jean-Baptiste , Calzado Carmen J. , Train Cyrille , Robert Vincent
Published: April 2010

The exchange channels governing the experimentally reported coupling constant (Jexpt=6 cm−1) value in the verdazyl-ligand based Cu(II) complex [Cu(hfac)2(imvdz)] are inspected using wave function-based difference dedicated configuration interaction calculations. The interaction between the two spin 1/2 holders is summed up in a unique coupling constant J. Nevertheless, by gradually increasing the level of calculation, different mechanisms of interaction are turned on step by step. In the present system, the calculated exchange interaction then appears alternatively ferromagnetic/antiferromagnetic/ferromagnetic. Our analysis demonstrates the tremendously importance of some specific exchange mechanisms. It is actually shown that both parts of the imvdz ligand simultaneously influence the ferromagnetic behavior which ultimately reaches Jcalc=6.3 cm−1, in very good agreement with the experimental value. In accordance with the alternation of J, it is shown that the nature of the magnetic behavior results from competing channels. First, an antiferromagnetic contribution can be essentially attributed to single excitations involving the π network localized on the verdazyl part. In contrast, the σ ligand-to-metal charge transfer (LMCT) involving the imidazole moiety affords a ferromagnetic contribution. The distinct nature σ/π of the mechanisms is responsible for the net ferromagnetic behavior. The intuitively innocent part of the verdazyl-based ligands is deeply reconsidered and opens new routes into the rational design of magnetic objects.
High-density highly collimated monoenergetic GeV ions from interaction of ultraintense short laser pulse with foil in plasma
Authors: Zhang Z. M. , He X. T. , Sheng Z. M. , Yu M. Y.
Published: April 2010

Two-dimensional particle-in-cell simulation is used to investigate the acceleration of foil ions by the radiation pressure of an ultraintense short laser pulse in the presence of a background plasma of proper density and length behind the foil. It is shown that under appropriate conditions a central foil segment with a transverse dimension ∼σL/2, where σL is the laser spot size, can be stably accelerated. In this plasma backed acceleration scheme, foil electron heating and ion expansion are greatly suppressed by the cool backside electrons that replace the expelled fast electrons in the target, so that a monoenergetic collimated GeV ion sheet is produced. The simulation results agree with that from a physical model for the stably accelerated foil segment.
Correlation between carrier localization, optical, and structural properties in multilayered GaN/Al0.5Ga0.5N quantum wells with an ultrathin inserted Al0.5Ga0.5N layer
Authors: Park Young S. , Kim Yongmin , Im Hyunsik
Published: April 2010

We report that the performance of the optical properties in multilayered GaN/Al0.5Ga0.5N quantum wells is improved by inserting an ultrathin (5 Å) Al0.5Ga0.5N layer in the middle of the GaN layers. A considerable redshift in the photoluminescence and the cathodoluminescence (CL) spectra is observed due to the additional strain along the growth direction resulting in piezoelectric polarization. The structural uniformity along the plane directions is investigated using two dimensional CL mapping. The results presented are useful for tuning the optical properties of multilayered heterojunction optoelectronic devices.
Evolution of microstructure and related properties of PbZr0.4Ti0.6O3 films on F-doped tin oxide with annealing temperature
Authors: Zhang T. , Hu G. J. , Bu H. J. , Wu J. , Chu J. H. , Dai N.
Published: April 2010

PbZr 0.4 Ti 0.6 O 3 films were fabricated on glass slices coated with a layer of F-doped transparent conductive tin oxide layer by chemical solution deposition. The evolution of microstructures and related properties of the PbZr0.4Ti0.6O3 films with annealing temperature were studied. The films show a perovskite phase and a crack-free surface morphology. The films annealed at >550 °C display a distinguishable layered structure consisting of dense and porous PbZr0.4Ti0.6O3 layers. The sample treated at 650 °C exhibits the largest average remanent polarization of 29.2 μC/cm2 and peak reflectivity of 95% among the films. 650 °C appears to be the best processing condition for the growth of PbZr0.4Ti0.6O3 multilayers with excellent ferroelectric and optical properties on F-doped tin oxide thin films.
Modeling the temperature induced degradation kinetics of the short circuit current in organic bulk heterojunction solar cells
Authors: Conings Bert , Bertho Sabine , Vandewal Koen , Senes Alessia , D’Haen Jan , Manca Jean , Janssen René A. J.
Published: April 2010

In organic bulk heterojunction solar cells, the nanoscale morphology of interpenetrating donor-acceptor materials and the resulting photovoltaic parameters alter as a consequence of prolonged operation at temperatures above the glass transition temperature. Thermal annealing induces clustering of the acceptor material and a corresponding decrease in the short circuit current. A model based on the kinetics of Ostwald ripening is proposed to describe the thermally accelerated degradation of the short circuit current of solar cells with poly(2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene) (MDMO-PPV) as donor and (6,6)-phenyl C61-butyric acid methyl ester (PCBM) as acceptor. The activation energy for the degradation is determined by an Arrhenius model, allowing to perform shelf life prediction.
Interactions between 180° and 360° domain walls in magnetic multilayer stripes
Authors: Mascaro Mark D. , Nam Chunghee , Ross C. A.
Published: April 2010

Magnetostatic interactions between 360° and transverse 180° domain walls in the NiFe and Co layers of Co/Cu/NiFe multilayer stripes are investigated by micromagnetic simulations. In 200 nm wide Co (5 nm)/Cu (5 nm) /NiFe (5 nm) stripes, stray fields from 360° domain walls in the Co layer strongly influence the magnetic behavior of the NiFe layer, promoting reverse domain nucleation and providing a pinning potential of order 100 Oe which impedes domain wall propagation. 360° domain walls may be useful as programmable pinning sites in magnetoelectronic logic or memory devices.
Invited Article: High-pressure techniques for condensed matter physics at low temperature
Authors: Feng Yejun , Jaramillo R. , Wang Jiyang , Ren Yang , Rosenbaum T. F.
Published: April 2010

Condensed matter experiments at high pressure accentuate the need for accurate pressure scales over a broad range of temperatures, as well as placing a premium on a homogeneous pressure environment. However, challenges remain in diamond anvil cell technology, including both the quality of various pressure transmitting media and the accuracy of secondary pressure scales at low temperature. We directly calibrate the ruby fluorescence R1 line shift with pressure at T=4.5 K using high-resolution x-ray powder diffraction measurements of the silver lattice constant and its known equation of state up to P=16 GPa. Our results reveal a ruby pressure scale at low temperatures that differs by 6% from the best available ruby scale at room T. We also use ruby fluorescence to characterize the pressure inhomogeneity and anisotropy in two representative and commonly used pressure media, helium and methanol:ethanol 4:1, under the same preparation conditions for pressures up to 20 GPa at T=5 K. Contrary to the accepted wisdom, both media show equal levels of pressure inhomogeneity measured over the same area, with a consistent ΔP/P per unit area of ±1.8%/(104 μm2) from 0 to 20 GPa. The helium medium shows an essentially constant deviatoric stress of 0.021±0.011 GPa up to 16 GPa, while the methanol:ethanol mixture shows a similar level of anisotropy up to 10 GPa, above which the anisotropy increases. The quality of both pressure media is further examined under the more stringent requirements of single crystal x-ray diffraction at cryogenic temperature. For such experiments we conclude that the ratio of sample-to-pressure chamber volume is a critical parameter in maintaining sample quality at high pressure, and may affect the choice of pressure medium.
GaN nanowire surface state observed using deep level optical spectroscopy
Authors: Armstrong A. , Li Q. , Lin Y. , Talin A. A. , Wang G. T.
Published: April 2010

Deep level defects in n-type GaN nanowires (NWs) with and without an epitaxially-grown AlGaN shell were compared using photoconductivity-mode deep level optical spectroscopy. Hole photoemission from a defect state located approximately 2.6 eV above the valence band was observed for GaN NWs but was not observed for AlGaN/GaN core-shell NWs, indicating that this deep level is associated with a GaN surface state. Identifying GaN NW surface states and developing an effective passivation mechanism is expected to aid in the understanding and improvement of GaN NW-based sensors and optoelectronics.
Vibrational and electronic energy levels of polyatomic transient molecules: Supplement 1
Authors: Jacox Marilyn E.
Published: April 2010

New information on the experimentally determined vibrational and electronic energy levels of approximately 500 neutral and ionic transient molecules possessing from 3 to 16 atoms has been evaluated and added to the previously established database for these species. There has been selective extension of the compilation to somewhat less reactive species such as HNCO, HCNO, H2O2, and cis- and trans-HONO, as well as to many transient molecules which include atoms beyond the third row of the Periodic Table. Electronic spectral data are also given for a number of transient molecules which possess more than six atoms. Radiative life-times and the principal rotational constants are included. Observations in the gas phase, in molecular beams, and in rare-gas and nitrogen matrices are evaluated. The types of measurement surveyed include conventional and laser-based absorption and emission techniques, laser absorption with mass analysis, and photoelectron spectroscopy.
Universal model for water costs of gas exchange by animals and plants
Authors: Woods H. Arthur , Smith Jennifer N.
Published: April 2010

For terrestrial animals and plants, a fundamental cost of living is water vapor lost to the atmosphere during exchange of metabolic gases. Here, by bringing together previously developed models for specific taxa, we integrate properties common to all terrestrial gas exchangers into a universal model of water loss. The model predicts that water loss scales to gas exchange with an exponent of 1 and that the amount of water lost per unit of gas exchanged depends on several factors: the surface temperature of the respiratory system near the outside of the organism, the gas consumed (oxygen or carbon dioxide), the steepness of the gradients for gas and vapor, and the transport mode (convective or diffusive). Model predictions were largely confirmed by data on 202 species in five taxa—insects, birds, bird eggs, mammals, and plants—spanning nine orders of magnitude in rate of gas exchange. Discrepancies between model predictions and data seemed to arise from biologically interesting violations of model assumptions, which emphasizes how poorly we understand gas exchange in some taxa. The universal model provides a unified conceptual framework for analyzing exchange-associated water losses across taxa with radically different metabolic and exchange systems.