bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of PFC power converters subject to time‐delayed feedback control
Authors: El Aroudi Abdelali , Orabi Mohamed
Published: May 2010

Power factor correction converters are power electronics circuits used as AC‐DC power supplies. These systems are well known to exhibit nonlinear phenomena such as subharmonic oscillations and chaotic regimes. These undesirable behaviors increase the THD and therefore can jeopardize enormously the system performances. In this paper, time delay feedback control is applied to stabilize a two‐stage power factor correction AC‐DC converter when it exhibits these instabilities under traditional controllers. This control technique introduces many advantages to the most and widely used average current mode control through widening the stability domain of the system. By appropriately selecting the time delay feedback gain and the time delay period, the undesirable subharmonic components are eliminated, whereas the desired ones remain unchanged. A harmonic balance approach is used for studying the dynamics of the system under the new control scheme and to obtain the stabilization domain. Copyright © 2010 John Wiley & Sons, Ltd.
Application of polychromatic flow cytometry to identify novel subsets of circulating cells with angiogenic potential
Authors: Estes Myka L. , Mund Julie A. , Mead Laura E. , Prater Daniel N. , Cai Shanbao , Wang Haiyan , Pollok Karen E. , Murphy Michael P. , An Caroline S. T. , Srour Edward F. , Ingram David A. , Case Jamie
Published: May 2010

Defining whether human circulating proangiogenic cells represent a subset of the hematopoietic system and express CD45 or are hematopoietic derivatives that do not express CD45 (and are called endothelial progenitor cells) remains controversial. We have previously developed a polychromatic flow cytometry (PFC) protocol to isolate subsets of hematopoietic cells and we now identify the circulating pool of CD34+CD45dim cells representing functional circulating hematopoietic stem and progenitor cells (CHSPCs) that can be separated on the basis of AC133 expression and report that the AC133+ subset of the CHSPCs enhances the growth of tumor blood vessels in vivo in immunodeficient mice. In addition, the ratio of AC133+ proangiogenic CHSPCs to AC133− nonangiogenic CHSPCs unambiguously correlates with the severity of the clinical state of patients with peripheral arterial disease. In sum, a PFC protocol validated via in vitro and in vivo analyses, can be used to interrogate the roles of human hematopoietic elements in the growth and maintenance of the vasculature. © 2010 International Society for Advancement of Cytometry
Cytohistological correlation of grading in breast carcinoma
Authors: Lingegowda Jyothi B. , MuddeGowda Prakash H. , Ramakantha Chatura K. , Chandrasekar H. R.
Published: May 2010

Assigning a tumor grade to breast cancer provides important prognostic information and guides optimal therapy. The present study was undertaken to grade breast carcinoma on aspirates by Robinson grading (RGS) and Scarff–Bloom–Richardson grading system (SBR). Histological grading was done according to Nottingham modification of Scarff–Bloom–Richardson method and the two cytological grading systems were compared.

Fifty cases of breast carcinoma with preoperative cytologic diagnosis were assigned tumor grade. Histologic grading was done on corresponding mastectomy or partially resected specimens. Statistical analysis was performed; correlation between cytologic and histologic grading was established using Spearman correlation coefficient. Regression analysis was done to assess the significance of each cytological feature.

Univariate analysis showed strong correlation (P < 0.01) for all features except dissociation. Multiple regression analysis of cytologic features revealed cell dissociation nucleoli and nuclear margin as the most influential features. A concordance of 72.5% between RGS (cyto) and SBR (cyto), 64% for RGS (cyto) and SBR (histo), 82% for SBR (cyto) and SBR (histo) was noted. There was a significant association (P < 0.001) between the grades assigned to cytologic and histologic specimens.

Cytologic grade could be used to predict histologic grade as significant relationship exists between grades assigned to cytologic and histologic specimens. Diagn. Cytopathol. 2011;39:251–257. © 2010 Wiley‐Liss, Inc.
Follow‐up of women with ASCUS in Chile
Authors: Fanny López , Orlando Quezada , Trinidad Barrios , Estefanía López
Published: May 2010

Atypical squamous cells of undetermined significance (ASCUS) is a cytological report that creates a dilemma for the cytologist and the clinician because it does not necessarily represent a pathological entity. To clarify this paradox we propose research into the monitoring of cytological and histological results for a period of 3 years from a cohort of women treated in the Primary Care Health Services of Santiago, Chile, who have received a first Pap ASCUS results in 2005. In the cytological reports, the national nomenclature was used, which is equivalent to the Bethesda System 2001. By applying the selection criteria, a cohort of 154 women was formulated, whereby at the end of the monitoring period, we found: 2 women with invasive carcinoma (1.3%), 33 women with high‐grade squamous intraepithelial lesions HSIL (21.4%), 32 women with low grade squamous intraepithelial lesions LSIL (20.8%), and 87 women with normal results (56.5%). The statistical analysis, by form of the tree of conditional probabilities, shows that when the 2nd smear is repeated within an accelerated time frame (2.7 months), it does not assist in elucidating this cytological entity, and should be repeated only after 6 months from the first ASCUS smear result. Thus, we found that one out of every two women showed no evidence of abnormal results throughout their cytological and histological monitoring. Diagn. Cytopathol. 2011;39:258–263. © 2010 Wiley‐Liss, Inc..
Cytomorphological patterns of M. bovis BCG and M. tuberculosis on fine needle aspiration biopsies: Does HIV make a difference?
Authors: Schubert Pawel T. , Cotton Mark F. , Wright Colleen A.
Published: May 2010

To determine if fine needle aspiration (FNAB) of mycobacterial lymphadenopathy can differentiate infection with M. bovis BCG (BCG) from M. tuberculosis (TB) and whether HIV status affects discriminatory cytological features.

A retrospective study of culture positive, fine needle aspiration biopsies of lymph nodes in children (<13 years) between 2003 and 2008.

A total of 77 aspirates were available for evaluation with 67 (87%) patients having known HIV status. BCG occurred at a younger age (6 months), predominantly axillary lymph nodes (90%) compared with TB (5 years and 20% axillary lymph nodes). Amorphous necrosis was only seen in aspirates fromTB lymph nodes, while in HIV negative children with TB, foamy macrophages were absent. OnZN staining there were more organisms in the BCG group and in HIV positive patients the organisms were present in both extra‐ and intracellular locations, whereas in the HIV negative patients the organisms were predominantly extracellular in location.

Demographic and cytomorphologic features that can assist in distinguishing between thetwo mycobacterial species include: age of patient, location of the lymph node, and presence/absence of amorphous necrosis and foamy macrophages on FNAB. However the only reliable method to identify the mycobacterial species is by mycobacterial culture and/orPCR. Diagn. Cytopathol. 2011;39:264–269. © 2010 Wiley‐Liss, Inc.
Role of brush cytology in the diagnosis of Barrett's esophagus: An analysis of eight cases
Authors: Padmavathy Femila , Siddaraju Neelaiah , Sistla Sarath Chandra
Published: May 2010

Although debatable, role of cytology in diagnosing Barrett's esophagus has been stressed by some authors. Our brief report analyses the role of brush cytology (BC) in its diagnosis.

Eight patients who presented with upper gastrointestinal (GI) manifestations and subsequently diagnosed to have Barrett's esophagus with or without adenocarcinoma on brush cytology (BC) or, endoscopic biopsy (EB) or, a combination of both the techniques were included in the study. In all the cases routine cytologic smears and histologic sections with relevant special stains (when essential) were studied. On cytology, the diagnosis of “Barrett's esophagus” was made when the esophageal brushings obtained from a region beyond 3 cm from the gastroesophageal junction showed closely intermingled clusters of squamous and columnar cells, or when there was evidence of intestinal metaplasia. Adenocarcinoma in Barrett's esophagus was diagnosed by the usual criteria for malignancy with features of adenocarcinoma. Cytologic diagnoses were correlated with the histologic diagnoses.

Of the eight cases, seven had histopathologic correlation of which six had evidence of BE on BC; four had cytohistologic concordance, of which three cases revealed adenocarcinoma arising in BE. Two endoscopic biopsies were nonrepresentative. In one case, cytology missed Barrett's esophagus. For two cases in which cytology detected Barrett's mucosa, biopsies were nonrepresentative.

Our study showed brush cytology (BC) to be a fairly reliable test for detecting Barrett's esophagus. Owing to its inherent advantage of sampling a wider and circumferential area, a technically well performed brushing procedure is likely to be more representative and superior than multiple endoscopic biopsies. Diagn. Cytopathol. 2011;39:60–64. © 2010 Wiley‐Liss, Inc.
Nonhealing ulcer—A rare initial presentation of chronic myeloid leukemia diagnosed on aspiration cytology
Authors: Wadhwa Neelam , Batra Madhu , Singh Bharat
Published: May 2010

Involvement of skin in hematologic malignancies is rare phenomena as majority of the dermatologic lesions in leukemia patients are nonleukemic. In the absence of preceding history of leukemia, the diagnosis is often a surprise. Chronic nonhealing ulcer on the back of a 65‐years‐old male prompted a fine needle aspiration from its base. Smears showed an unexpected picture comprising of leukocytes in various stages of maturation against a hemorrhagic background. A cytologic diagnosis of leukemia cutis was given. Subsequent hematologic investigations revealed chronic myeloid leukemia in chronic phase. Cutaneous involvement is a rare initial presentation of leukemia in an otherwise asymptomatic patient and also an uncommon cause of nonhealing ulcer. Aspiration cytology scores over biopsy in not only being a rapid and easy diagnostic tool but also allows better appreciation of cellular details like cytoplasmic granules. Diagn. Cytopathol. 2011;39:135–137. © 2010 Wiley‐Liss, Inc.
Prevalence of anal cytological abnormalities in women with positive cervical cytology
Authors: Calore Edenilson E. , Giaccio Claudia Maria Serafim , Nadal Sidney R.
Published: May 2010

The objective of this study was to estimate the prevalence of cytological abnormalities of the anal mucosa in women with positive cervical cytology, but without macroscopic anal lesion. Ultimately we postulated if the anal mucosa may be a reservoir of HPV, which would allow the reinfection of cervix. Forty‐nine patients with abnormal cervical cytology were selected for this work. In a period not exceeding one week of collecting cervix cytology, two swab specimens of the anal canal were also collected. Women diagnosed with cervical HSIL by Pap smear were referred for colposcopy with biopsy of the lesions, to confirm the cytologic diagnosis and ablation of the lesion. We demonstrated a high prevalence of anal squamous intraepithelial lesions in patients with cervical squamous intraepithelial lesions (29 of the total of 49 patients = 59.2%). Of the 20 cases of cervical LSIL, 11 (55%) had abnormal anal cytology. Of the 26 cases with cervical HSIL, 16 (61.5%) had abnormal anal cytology. So, there was a discrete higher prevalence of abnormal anal cytology in cases of high‐grade cervical squamous lesions (cervical HSIL). These results help to support the hypothesis that the anal mucosa is a reservoir of HPV, which can be a source of re‐infection for the cervix. However, there was no significant association between the practice of anal sex and the prevalence of anal cytological abnormalities. These facts are epidemiologically important for future programs for population eradication of cervical lesions related to HPV. Diagn. Cytopathol. 2011;39:323–327. © 2010 Wiley‐Liss, Inc.
Gigantomastia in pregnancy with an accessory axillary mass masquerading as inflammatory carcinoma
Authors: Lokuhetty M. D. S. , Saparamadu P. A. M. , Al‐Sajee D. M. A. , Al‐Ajmi R.
Published: May 2010

Giagantomastia is a rare disorder known to occur in pregnancy, causing enlargement of the breasts greater than that of gravid enlargement. The histological features of gigantomastia are glandular hyperplasia and an increase of stromal tissue. Illustrated by one documented case, cytomorphology of gigantomastia was misdiagnosed as a phyllodes tumor. We document the cytomorphology of an axillary mass in a gravid woman of 24 years with gigantomastia. She presented in her first trimester with bilateral mastalgia and swelling, nonresponsive to antibiotics. Imaging excluded mass breast lesions and a pituitary prolactinoma. The breasts progressively enlarged, became warm, tender, and developed skin ulcerations and a peau d'orange appearance. Subsequently she developed a mass in her left axilla. On aspiration of the mass, some of the cytomorphological features were suspicious for a metastasis, which correlated well with her clinical features. Careful evaluation suggested cytomorphology to be compatible with benign accessory breast tissue with possible hormone related changes of pregnancy. Histology of the excised axillary mass confirmed this diagnosis. Thus, awareness of this rare condition and careful evaluation is mandatory to avoid misdiagnosis in a similar clinical context. Diagn. Cytopathol. 2011;39:141–143. © 2010 Wiley‐Liss, Inc.
Retrospective evaluation of instituted standard adequacy criteria for on‐site adequacy assessment of thyroid fine‐needle aspiration
Authors: Jing Xin , Wey Elizabeth , Michael Claire W.
Published: May 2010

This retrospective study was conducted to investigate the impact of using instituted standard criteria for on‐site assessment of specimen adequacy on fine‐needle aspiration (FNA) diagnosis of thyroid nodules. The study included a total of 1,031 thyroid FNAs that were performed and assisted with on‐site adequacy assessment using instituted standard criteria from July 2006 to March 2009. Adequate specimens require the presence of at least six groups of follicular cells in total on Diff–Quik stained smears with a minimum of 10 cells in each group. Agreement on specimen adequacy between on‐site and final assessment, nondiagnostic rate, distribution of cytologic diagnoses, and cytohistologic concordance for cases with surgical follow‐up was evaluated. Implementing the instituted standard criteria resulted in 93% level of agreement on specimen adequacy between on‐site and final assessment. Nondiagnostic rate upon final assessment was 10.7%. Cytohistologic concordant rate reached 93.9% and 82.3% for nonneoplastic and neoplastic lesions, respectively. Most importantly, this approach to standardization not only provided diagnostic consistency among cytopathologists, but also minimized confusions and enhanced effective communication. Thus, high satisfactions have been achieved from endocrinologists/radiologists who utilized our on‐site assessment service and/or participated in the management of thyroid nodules. Diagn. Cytopathol. 2011;39:391–394. © 2010 Wiley‐Liss, Inc.
Pleomorphic hyalinizing angiectatic tumor: Cytomorphologic features on fine‐needle aspiration
Authors: Cimino‐Mathews Ashley , Ali, Syed Z.
Published: May 2010

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare low‐grade neoplasm occurring predominantly in the subcutaneous tissue of the lower extremity, which is characterized histologically by intermixed bland spindle cells and larger pleomorphic cells, ectatic blood vessels with fibrin, and prominent hyalinization. Here we describe the cytologic features of PHAT seen on fine‐needle aspiration of a right calf mass in a 46‐year‐old man. The smears were cellular, composed predominantly of bland spindle cells dispersed singly as well as in tissue fragments and characterized by open chromatin and small nucleoli. A second population of pleomorphic spindle cells with coarse chromatin, prominent nucleoli, and occasional intranuclear pseudoinclusions was also present. Many of the pleomorphic cells surrounded hyalizined vessels. No mitotic figures were identified. The cytologic diagnosis was a “spindle cell lesion, NOS” with the differential diagnosis including benign lesions and low‐grade neoplasms, including PHAT and schwannoma. Diagn. Cytopathol.2011;39:214–217. © 2010 Wiley‐Liss, Inc.
Sensitivity of fine‐needle aspiration for papillary carcinoma of the thyroid correlates with tumor size
Authors: Renshaw Andrew A.
Published: May 2010

Fine‐needle aspiration (FNA) of the thyroid for papillary carcinomas is highly sensitive. We sought to determine if the sensitivity of FNA for papillary carcinoma is correlated with the size of the tumor.

We reviewed the results of thyroid resections for the last 12 years and correlated the findings with clinical and cytologic information.

During the time period, a total of 1,331 resections were performed, and a total of 501 papillary carcinomas were identified, including 291 classic tumors, 65 follicular variants, and 145 “incidental” tumors. Sensitivity for all tumors was strongly correlated with tumor size and ranged from a sensitivity of 0–3% for tumors 2 mm or less, 90% for tumors 1–3 cm (220/244, P < 0.001) and 83% for tumors above 3 cm (47/59, P = 0.02). Abnormal FNAs of classic tumors were always recognized as papillary (262/262) compared to only 49% of follicular variants (32/65, P < 0.001).

The sensitivity of FNA for papillary thyroid carcinoma is strongly correlated with tumor size. Tumors smaller than 0.5 cm and tumors larger than 3 cm may be more difficult to successfully aspirate on FNA, and the follicular variant may be more difficult to recognize as papillary. Diagn. Cytopathol., 2011. © 2010 Wiley‐Liss, Inc.
Electrochemical study of spiramycin and its determination in pharmaceutical preparation
Authors: Youssef Rasha M. , Maher Hadir M.
Published: May 2010

Spiramycin (SPY) is a medium‐spectrum antibiotic with high effectiveness against Gram‐positive bacteria. The voltammetric behaviour of spiramycin was studied using differential pulse polarography (DPP) and square wave polarography (SWP). The drug in Britton‐Robinson buffer (pH 11.5) is reduced at − 1.45 V, giving rise to a well‐defined cathodic peak using hanging mercury drop electrode (HMDE) versus Ag/AgCl electrode. This peak is attributed to the reduction of the aldehyde group. The results proved that the reduction of SPY is an irreversible diffusion‐controlled process. The diffusion current‐concentration relationship was shown to be rectilinear over the range of 20–80 and 0.8–80 µg ml−1 using DPP and SWP modes, respectively, with detection limit of 8.5 µg ml−1 (1.01 × 10−5 M) and 0.46 µg ml−1 (5.46 × 10−7 M) for DPP and SWP modes, respectively. A mechanism is postulated for the reduction of SPY. The proposed techniques were successfully applied to the determination of the studied compound either in pure form or in its formulation. Copyright © 2010 John Wiley & Sons, Ltd.
Coupled ecological–hydrological processes
Authors: Manfreda Salvatore , Smettem Keith , Iacobellis Vito , Montaldo Nicola , Sivapalan Murugesu
Published: May 2010

The papers in this issue represent a selection of the presentations made at the session entitled “Climate‐soil and vegetation interactions in ecological–hydrological processes” of the European Geophysical Union General Assembly. The special issue “Coupled Ecological–Hydrological Processes” focuses on different aspects of Ecohydrology that can be summarized in the following topics: soil moisture dynamics, soil–plant interactions, vegetation modelling and effects of climate change on natural ecosystems. Copyright © 2010 John Wiley & Sons, Ltd.
Syntheses, Structures and Magnetic Properties of Trinuclear CuIIMIICuII (M = Cu, Ni, Co and Fe) and Tetranuclear [2×1+1×2] CuIIMnII–2CuII Complexes Derived from a Compartmental Ligand: The Schiff Base 3‐Methoxysalicylaldehyde Diamine Can also Stabilize a Cocrystal
Authors: Biswas Arpita , Ghosh Meenakshi , Lemoine Pascale , Sarkar Sohini , Hazra Susanta , Mohanta Sasankasekhar
Published: May 2010

The present investigation describes syntheses, characterization and studies of the mononuclear compound [CuIIL⊂(H2O)] (1), the triangular, trinuclear monophenoxido‐bridged compounds [{CuIIL}2MII(H2O)2](ClO4)2·nH2O [2 (M = Cu, n = 0), 3 (M = Ni, n = 3), 4 (M = Co, n = 0), 5 (M = Fe, n = 0)] and the tetrametallic self‐assembled complex [{CuIILMnII(H2O)3}{CuIIL}2](ClO4)2·H2O (6) derived from compartmental Schiff base ligand, H2L, which is the [2+1] condensation product of 3‐methoxysalicylaldehyde and trans‐1,2‐diaminocyclohexane. Single‐crystal X‐ray structures of 2, 5 and 6 were determined. Two pairs of terminal···central metal ions in the trinuclear cores in 2 and 5 are monophenoxido‐bridged. Interestingly, the CuO6 and FeO6 environments have tetragonally compressed octahedral geometries. On the other hand, the structure of 6 reveals that it is a [2×1+1×2] cocrystal of one diphenoxido‐bridged dinuclear [CuIILMnII(H2O)3]2+ dication and two mononuclear [CuIIL] moieties. Cocrystallization in 6 takes place as a result of water encapsulation. The variable‐temperature (2–300 K) magnetic susceptibilities of compounds 2–6 have been measured. The exchange integrals obtained are: the CuII3 compound 2, J = –78.9 cm–1; the CuIINiIICuII compound 3, J = –22.8 cm–1; the CuIICoIICuII compound 4, J = –7.8 cm–1; the CuIIFeIICuII compound 5, J = –3.0 cm–1; the CuII3MnII compound 6, J = –15.1 cm–1. The monophenoxido‐bridging core in 3 and 4 has been proposed after comparison of the structures and magnetic properties of these two compounds with those of 2, 5 and related other compounds. This paper presents rare examples of monophenoxido‐bridged CuIIMIICuII (M = Cu, Ni, Co and Fe) compounds, provides an understanding of the structures from magnetic exchange integrals, and, most importantly, reports on the first example of a cocrystal derived from a 3‐methoxysalicylaldehyde diamine compartmental ligand.
Examination of Water Oxidation by Catalysts Containing Cofacial Metal Sites
Authors: Wasylenko Derek J. , Ganesamoorthy Chelladurai , Koivisto Bryan D. , Berlinguette Curtis P.
Published: May 2010

A series of bimetallic complexes were developed to examine how the distance between two juxtaposed {Ru(tpy)(bpy)Cl}1+ (2; tpy = 2,2′;6′,2″‐terpyridine; bpy = 2,2′‐bipyridine) units affect catalytic behavior in the context of water oxidation. The directionality imposed by the organic backbone for each of these “Pacman” complexes elicits idealized M···M distances of ca. 5, 10, and 12 Å for 4–6, respectively. Cyclic voltammetry indicates that intramolecular electronic communication occurs between the metal sites of 4, while the metal fragments are essentially electrochemically isolated for 5 and 6. Despite the disparate distances between the metal sites, each of these complexes are shown to mediate the CeIV‐driven oxidation of water in acidic media. Dioxygen evolution was monitored with an optical probe in the headspace of the reaction vessel, and independently verified by the detection of appropriate ratios of 18O‐18O, 18O‐16O, and 16O‐16O in GC–MS experiments using 18O‐labeled water. A fitting of the dioxygen evolution data indicates catalytic behavior that is first‐order with respect to catalyst concentration in all cases. This finding rules out the possibility that dioxygen formation occurs independently at each metal site simultaneously, and leaves open the possibility that O–O bond formation occurs by either both metal sites acting cooperatively, or at one metal site independent of the other. Taking into account the significant electrostatic repulsion between the two metal fragments in higher oxidation levels, we contend that the latter mechanism is the more likely scenario. Notwithstanding, complex 4 generates the largest kobs values among the bimetallic series, which suggests that the close proximity of another metal may benefit catalysis. A comparison of kobs and catalytic turnover numbers (TONs) of the bimetallic systems to the mononuclear complex 2, however, does not indicate an improvement in catalytic behavior. This is an important observation in the collective pursuit of efficient water oxidation catalysts.
Solid‐State Structures and Properties of Europium and Samarium Hydrides
Authors: Kohlmann Holger
Published: May 2010

The structural chemistry of europium and samarium hydrides in the solid state is very rich, ranging from typical ionic hydrides following the hydride‐fluoride analogy to complex transition metal hydrides and interstitial hydrides. While crystal structure, electrical, and magnetic properties suggest that europium is divalent in all hydrides investigated so far, samarium is easily transformed to a trivalent oxidation state in its hydrides and shows similarities to other lanthanide(III) hydrides. The problem of neutron absorption of europium and samarium, hampering crystal structure solution and limiting the available structural information, is discussed in detail, and practical solutions for neutron diffraction experiments are given.
Trapped in a Complex: the 1,2,4,5‐Tetrakis(tetramethylguanidino)benzene Radical Cation (ttmgb+·) with a Bisallylic Structure
Authors: Trumm Christine , Hübner Olaf , Kaifer Elisabeth , Himmel Hans‐Jörg
Published: May 2010

In this work we follow the reaction of the strong electron donor 1,2,4,5‐tetrakis(tetramethylguanidino)benzene (ttmgb) with CuII nitrate. Three binuclear CuII complexes were isolated as products of this reaction. Depending on the reaction conditions, especially the molar ratio of the two reactants, the ttmgb ligand in these complexes is neutral, mono‐ or dicationic. All three complexes were structurally characterized. In addition to the experimental studies, quantum chemical calculations were carried out, which, in combination with experimental magnetic (SQUID) curves, especially shed light on the magnetic superexchange. The binuclear CuII complex of the ttmgb radical cation represents a three‐spin system. The SQUID magnetic data as well as the results of quantum chemical calculations indicate strong ferromagnetic copper‐ligand coupling.
Spectroscopy of High‐Energy States of Lanthanide Ions
Authors: Reid Michael F. , Hu Liusen , Frank Sebastian , Duan Chang‐Kui , Xia Shangda , Yin Min
Published: May 2010

We discuss recent progress and future prospects for the analysis of the 4fN–15d excited states of lanthanide ions in host materials. We demonstrate how ab initio calculations for Ce3+ in LiYF4 may be used to estimate crystal‐field and spin‐orbit parameters for the 4f1 and 5d1 configurations. We show how excited‐state absorption may be used to probe the electronic and geometric structure of the 4fN–15d excited states in more detail and we illustrate the possibilities with calculations for Yb2+ ions in SrCl2.
Addition of Azomethine Ylides to Aldehydes: Mechanistic Dichotomy of Differentially Substituted α‐Imino Esters
Authors: Seashore‐Ludlow Brinton , Torssell Staffan , Somfai Peter
Published: May 2010

The formal 1,3‐dipolar cycloaddition of azomethine ylides and aldehydes is explored, as hydrolysis of the resulting oxazolidine product gives facile access to valuable syn‐β‐aryl‐β‐hydroxy‐α‐amino esters. The use of using benzaldehyde‐derived imines as the ylide precursor results in 1,3‐dipolar cycloaddition with high conversions but low diastereoselectivity. In contrast, the employment of benzophenone‐derived imines as the ylide precursor results in an aldol reaction, which gives the intermediate oxazolidine in high diastereoselectivity and requires a weak acid catalyst to achieve higher conversions.
Synthetic Exploration of Oxacalix[2]arene[2]quinazolines
Authors: Van Rossom Wim , Kishore Lingam , Robeyns Koen , Van Meervelt Luc , Dehaen Wim , Maes Wouter
Published: May 2010

Oxacalix[2]arene[2]quinazoline macrocycles were prepared in good yields, as mixtures of syn and anti isomers, through nucleophilic aromatic substitution cyclocondensation reactions of 2,4‐dichloroquinazolines and m‐dihydroxybenzenes. The macrocyclization conditions were optimized and the isomeric ratio was investigated by means of one‐step and fragment‐coupling approaches. The oxacalixarene substitution pattern could easily be varied by altering the dichloroquinazolinyl biselectrophilic and dihydroxyaryl bisnucleophilic building blocks. The solid‐state (1,3‐alternate) conformational behavior and the oxacalix[4]arene cavity size were explored by X‐ray diffraction studies.
Acidity as a factor in leaching of copper, chromium and arsenic from CCA-treated dimension lumber
Authors: Warner John E. , Solomon Keith R.
Published: May 2010

Samples of new and weathered utility lumber pressure-treated with chromated copper arsenate (CCA) were tested for leaching of copper, chromium and arsenic by submersion in leaching baths of various pH levels. Accumulation of metals was monitored in leachate at pH 3.5, 4.5, 5.5, 7.0 and 8.5 over a period of 40 d by atomic absorption spectroscopy. Copper, chromium and arsenic were found in the leachate of both new and weathered wood with significantly higher levels of all metals occurring at acidic pH levels. Up to 100% of CCA treatment metals were found to have leached at pH 3.5, whereas a maximum of 9% of metals leached at pH 8.5. Metal leaching was found to be higher in citric acid than in dilute sulfuric acid solutions. Leaching of copper, chromium and arsenic was not proportional to the amount of metal present before leaching.
A bioaccumulation bioassay for freshwater sediments
Authors: Mac Michael J. , Noguchi George E. , Hesselberg Robert J. , Edsall Carol C. , Shoesmith John A. , Bowker James D.
Published: May 2010

A laboratory bioassay is described for determining the bioavailability of contaminants from freshwater sediments. The bioassay consists of 10-d exposures to whole sediments under flow-through conditions. After testing five species, the fathead minnow (Pimephales promelas) and the earthworm (Lumbricus terrestris) were recommended for use in the test. When the availability of polychlorinated biphenyls (PCBs), Hg and Zn from Great Lakes sediments was examined in laboratory exposures, only the PCBs were accumulated. A field validation study demonstrated that the magnitude of accumulation in laboratory exposures was similar to that in organisms caged in the field. A protocol is recommended for using the test as a standardized bioaccumulation bioassay.
Opportunistic multiuser scheduling with reduced feedback load
Authors: Al‐Harthi Yahya S.
Published: May 2010

In this paper, we propose a reduced feedback opportunistic scheduling (RFOS) algorithm that reduces the feedback load while preserving the performance of opportunistic scheduling (OS). The RFOS algorithm is a modified version of our previously proposed algorithm, the DSMUDiv algorithm. The main difference is that RFOS consists of a probing process (search process) and a requesting feedback process based on a threshold. The threshold value is variable, and it depends on the probing process. To reduce the feedback rate, a quantised value indicating the modulation level is fed back, instead of the full value of the signal‐to‐noise ratio (SNR), which we call quantised SNR. The paper includes the closed‐form expressions of the probing load, feedback load and spectral efficiency. In addition, we investigate the effect of the scheduling delay on the system throughput (STH). Under slow Rayleigh fading assumption, we compare RFOS algorithm with the DSMUDiv and optimal (full feedback load) selective diversity scheduling algorithms. Copyright © 2010 John Wiley & Sons, Ltd.
Semiparametric forecast intervals
Authors: Wu Jason J.
Published: May 2010

Consider forecasting the economic variable Yt+h with predictors Xt, where h is the forecast horizon. This paper introduces a semiparametric method that generates forecast intervals of Yt+h|Xt from point forecast models. First, the point forecast model is estimated, thereby taking advantage of its predictive power. Then, nonparametric estimation of the conditional distribution function (CDF) of the forecast error conditional on Xt builds the rest of the forecast distribution around the point forecast, from which symmetric and minimum‐length forecast intervals for Yt+h|Xt can be constructed. Under mild regularity conditions, asymptotic analysis shows that (1) regardless of the quality of the point forecast model (i.e., it may be misspecified), forecast quantiles are consistent and asymptotically normal; (2) minimum length forecast intervals are consistent. Proposals for bandwidth selection and dimension reduction are made. Three sets of simulations show that for reasonable point forecast models the method has significant advantages over two existing approaches to interval forecasting: one that requires the point forecast model to be correctly specified, and one that is based on fully nonparametric CDF estimate of Yt+h|Xt. An application to exchange rate forecasting is presented. Copyright © 2010 John Wiley & Sons, Ltd.
Pricing real options under the constant elasticity of variance diffusion
Authors: Carlos Dias José , Pedro Vidal Nunes João
Published: May 2010

Much of the work on real options assumes that the underlying state variable follows a geometric Brownian motion with constant volatility. This paper uses a more general assumption for the state variable process that better captures the empirical regularities found in commodity markets. We use the constant elasticity of variance diffusion, where volatility is a function of underlying asset prices, and we provide analytic solutions for perpetual American options. We show that a firm that uses the standard lognormal assumption is exposed to significant errors of analysis, which may lead to nonoptimal investment and disinvestment decisions. © 2010 Wiley Periodicals, Inc. Jrl Fut Mark 31:230–250, 2011
AP2 transcription factor induces apoptosis in retinoblastoma cells
Authors: Li Xiaodong , Glubrecht Darryl D. , Godbout Roseline
Published: May 2010

The underlying cause of human retinoblastoma is complete inactivation of both copies of the RB1 gene. Other chromosome abnormalities, with the most common being extra copies of chromosome arm 6p, are also observed in retinoblastoma. The RB protein has previously been shown to interact with TFAP2 transcription factors. Here, we show that TFAP2A and TFAP2B, which map to chromosome arm 6p, are expressed in the amacrine and horizontal cells of human retina. TFAP2A RNA can readily be detected in retinoblastoma cell lines and tumors; however, the great majority of retinoblastoma cell lines and tumors are completely devoid of TFAP2A protein and TFAP2B RNA/protein. Transfection of TFAP2A and TFAP2B expression constructs into retinoblastoma cells induces apoptosis and inhibits proliferation. Our results suggest that a consequence of loss of RB1 gene function in retinoblastoma cells is inactivation of TFAP2A and TFAP2B function. We propose that inability to differentiate along the amacrine/horizontal cell lineages may underlie retinoblastoma tumor formation. © 2010 Wiley‐Liss, Inc.
Mineralogy, geochemistry and geodynamic setting of the granitoids from NW Iran
Authors: Saki Adel
Published: May 2010

The Mahneshan granitoids intruded the Neoproterozoic‐Lower Cambrian regional metamorphic rocks in northwestern Iran. These granitoids consisting mainly of K‐feldspar, plagioclase, quartz, muscovite, garnet and biotite display a number of subtypes in terms of structure, texture and mineralogy. Geochemically, they are peraluminous and (or) slightly peraluminous with variable normative corundum contents (0.28–4.50%), and medium to high potassic with calc‐alkaline affinity. Chondrite‐normalized REE patterns indicate that these granitoids can be divided into three distinct groups, supported by petrographic data. The REE patterns of the first group are shallow‐sloping in LREE relative to HREE ([La/Yb]n = 1.37–2.48), exhibiting pronounced negative Eu (Eu/Eu* = 0.23–0.35). The second group granitoids are characterized by strong LREE‐enrichment relative to HREE ([La/Yb]n = 3–6.20), with positive Eu anomalies (Eu/Eu* = 1.15–1.47). The third group of granitoids is depleted in the middle REE relative to other LREE and HREE. These REE patterns suggest the role of plagioclase and hornblende in their source of granitoids for group 1 and groups 2 and 3, respectively. The trends of Eu/Eu* ratio versus silica contents suggest mixing of mafic material with components formed by crustal melting with a plagioclase‐rich residue. Furthermore, thermobarometric estimations indicate that these rocks may have been formed at depths of 15–18 km at relatively low temperatures. The Mahneshan granitoids are S‐type and may have been emplaced in a syn‐ to post‐collisional tectonic setting, consistent with an origin of water‐saturated magmas with heterogeneous composition derived from different crustal rocks. Copyright © 2010 John Wiley & Sons, Ltd.
Control of oligodendrocyte generation and proliferation by Shp2 protein tyrosine phosphatase
Authors: Zhu Ying , Park Jinsil , Hu Xuemei , Zheng Kang , Li Hong , Cao Qilin , Feng Gen‐Sheng , Qiu Mengsheng
Published: May 2010

Extracellular signals play essential roles in controlling the proliferation and differentiation of oligodendrocyte progenitor cells in the developing central nervous system. However, the intracellular pathways that transduce these extrinsic signals remain to be elucidated. In this study, we showed that conditional ablation of the nonreceptor tyrosine phosphatase Shp2 in Olig1‐expressing oligodendrocyte lineage resulted in dramatic reduction in the generation and proliferation of oligodendrocyte progenitor cells in the spinal cord. Maturation and myelination of oligodendrocytes were also compromised in the Shp2 mutants. The deficits in oligodendrocyte development in Shp2 mutants nearly phenocopied those observed in PDGF‐A mutants, suggesting that Shp2 is a crucial component in transducing PDGF‐A signals in the control of oligodendrocyte proliferation and maturation. © 2010 Wiley‐Liss, Inc.
Secondary sensory area SII is crucially involved in the preparation of familiar movements compared to movements never made before
Authors: Beudel M. , Zijlstra S. , Mulder Th. , Zijdewind I. , de Jong B.M.
Published: May 2010

Secondary sensorimotor regions are involved in sensorimotor integration and movement preparation. These regions take part in parietal‐premotor circuitry that is not only active during motor execution but also during movement observation and imagery. This activation particularly occurs when observed movements belong to one's own motor repertoire, consistent with the finding that motor imagery only improves performance when one can actually make such movement. We aimed to investigate whether imagery or observation of a movement that was never made before causes parietal‐premotor activation or that the ability to perform this movement is indeed a precondition. Nine subjects [group Already Knowing It (AKI)] could abduct their hallux (moving big toe outward). Seven subjects initially failed to make such movement (Absolute Zero A0 group). They had to imagine, observe, or execute this movement, whereas fMRI data were obtained both before and after training. Contrasting abduction observation between the AKI‐group and A0‐group showed increased left SII and supplementary motor area activation. Comparing the observation of hallux flexion with abduction showed increased bilateral SII activation in the A0 and not in the AKI group. Prolonged training resulted in equal performance and similar cerebral activation patterns in the two groups. Thereby, conjunction analysis of the correlations on subject's range of abduction during execution, imagery, and observation of hallux abduction showed exclusive bilateral SII activation. The reduced SII involvement in A0 may imply that effective interplay between sensory predictions and feedback does not take place without actual movement experience. However, this can be acquired by training. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Single subject task‐related BOLD signal artifact in a real‐time fMRI feedback paradigm
Authors: Zhang Xiaochu , Ross Thomas J. , Jo Salmeron Betty , Yang Shaolin , Yang Yihong , Stein Elliot A.
Published: May 2010

Real‐time functional magnetic resonance imaging (rtfMRI) has been proposed as a method of providing feedback to develop a participant's ability to control his or her own neuronal activity. However, this BOLD signal is vulnerable to contamination from nonneuronal sources that can also be shaped by the feedback provided. Here we illustrate an artifact found while training participants to control signal from an ROI in the insula. As the artifact was directly behind the eye and the experiment used an echo‐planar imaging (EPI) sequence with phase encoding direction that included the orbits and the insula in the same line, we hypothesized that the artifact was due to eye motion. We demonstrate a reduced training effect when eyeball signal is regressed out of the data and reproduce the artifact with block design voluntary eye movement. Further, using independent components analysis on historical data, we find the artifact is common in BOLD data, but typically not task‐correlated, even in tasks where one might expect differing amounts of eye movement in the active task blocks. The artifact, thus, does not significantly impact group results in typical fMRI experiments. Finally, we demonstrate this particular artifact can be avoided in rtfMRI experiments by ensuring that the phase encoding direction does not project any eye movement related artifact onto the ROI being used for feedback training. Our findings underscore the importance of taking great care in designing rtfMRI feedback procedures to avoid contamination with nonneuronal sources of BOLD signal alteration. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Disorder‐specific dysfunctions in patients with attention‐deficit/hyperactivity disorder compared to patients with obsessive‐compulsive disorder during interference inhibition and attention allocation
Authors: Rubia Katya , Cubillo Ana , Woolley James , Brammer Michael J. , Smith Anna
Published: May 2010

Background: Abnormalities in inhibitory control and underlying fronto‐striatal networks is common to both attention deficit hyperactivity disorder (ADHD) and obsessive‐compulsive‐disorder (OCD). The aim of this study was to investigate disorder‐specific abnormalities in neural networks mediating interference inhibition and selective attention. Method: Event‐related functional magnetic resonance imaging (fMRI) was used to compare brain activation of boys with ADHD (18), with OCD (10), and healthy boys during (20) during a Simon task that measures interference inhibition and controls for and therefore comeasures attention allocation. Results: During interference inhibition, both patient groups shared mesial frontal dysfunction compared to controls. Disorder‐specific dysfunctions were observed in OCD patients in dorsolateral prefrontal cortex during the oddball condition and in ADHD patients in inferior parietal lobe during interference inhibition and in caudate and posterior cingulate during the simpler oddball condition. The decreased activation in caudate and cingulate in ADHD was furthermore negatively correlated with ADHD symptoms and positively with OCD behavioral traits. Conclusions: The study shows that ADHD and OCD patients have shared but also disorder‐specific brain dysfunctions during interference inhibition and attention allocation. Both disorders shared dysfunction in mesial frontal cortex. Disorder‐specific dysfunctions, however, were observed in dorsolateral prefrontal cortex in OCD patients and in caudate, cingulate, and parietal brain regions in ADHD patients. The disorder‐specific dissociation of striato‐cingulate activation that was increased in OCD compared to ADHD patients, was furthermore inversely related to the symptomatology of the two disorders, and may potentially reflect differential dopamine modulation of striatal brain regions. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Embodied visual perception of distorted finger postures
Authors: Schürmann Martin , Hlushchuk Yevhen , Hari Riitta
Published: May 2010

Bodily abnormalities in other persons often evoke an uneasy feeling, even disgust. Here, we studied the brain basis of such perceptual salience by presenting static pictures of distorted hand postures to healthy subjects during functional magnetic resonance imaging. Cortical activation sensitive to distorted (vs. natural) finger postures was found—with right‐hemispheric dominance—in the primary motor cortex, postcentral somatosensory areas, amygdala, and insula, and bilaterally in the putamen. This activation pattern suggests that the instantaneous “gut feelings” during the observation of bodily distortions in others are related to embodied percepts that also involve affect‐related brain areas. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Reduced somatosensory activations in swallowing with age
Authors: Malandraki Georgia A. , Perlman Adrienne L. , Karampinos Dimitrios C. , Sutton Bradley P.
Published: May 2010

Understanding the neural functional organization of swallowing in healthy elders is essential in diagnosing and treating older adults with swallowing difficulties. The primary aims of this investigation were to identify the neural activation sites of different components of deglutition in healthy elders using functional Magnetic Resonance Imaging (fMRI) and to investigate age differences in the neural control of swallowing. Ten young (age range 19–25 years of age) and nine older (age range 66–77 years of age) right‐handed healthy individuals were scanned in a 3‐Tesla MRI scanner. Subjects were visually cued for both a “Swallow” task and for component/control tasks (“Prepare to swallow,” “Tap your tongue,” and “Clear your throat”). Behavioral interleaved gradient (BIG) methodology was used to address movement related artifacts. Between‐group comparisons revealed statistically stronger activations in the primary somatosensory cortex of young adults during the motor tasks examined. Both groups showed activations in the major motor areas involved in the initiation and execution of movement; however, areas involved in sensory processing, sensorimotor integration and/or motor coordination and control, showed reduced or limited activity in the elderly. Potential implications of these findings for clinical practice are discussed. Hum Brain Mapp, 2011. © 2010 Wiley‐Liss, Inc.
Evaluating the impact of community‐based health interventions: evidence from Brazil's Family Health Program
Authors: Rocha Romero , Soares Rodrigo R.
Published: May 2010

This paper analyzes the direct and indirect impacts of Brazil's Family Health Program, using municipality level mortality data from the Brazilian Ministry of Health, and individual level data from the Brazilian household survey. We estimate the effects of the program on mortality and on household behavior related to child labor and schooling, employment of adults, and fertility. We find consistent effects of the program on reductions in mortality throughout the age distribution, but mainly at earlier ages. Municipalities in the poorest regions of the country benefit particularly from the program. For these regions, implementation of the program is also robustly associated with increased labor supply of adults, reduced fertility, and increased school enrollment. Evidence suggests that the Family Health Program is a highly cost‐effective tool for improving health in poor areas. Copyright © 2010 John Wiley & Sons, Ltd.