bluuebunny/crossref_metadata_2025 huggingface dataset:
Biocalcification in porcelaneous foraminifera
Authors: Dubicka Zofia , Tyszka Jarosław , Pałczyńska Agnieszka , Höhne Michelle , Bijma Jelle , Janse Max , Klerks Nienke , Bickmeyer Ulf
Published: February 2024

Living organisms control the formation of mineral skeletons and other structures through biomineralization. Major phylogenetic groups usually consistently follow a single biomineralization pathway. Foraminifera, which are very efficient marine calcifiers, making a substantial contribution to global carbonate production and global carbon sequestration, are regarded as the only exception. This phylum has been commonly thought to follow two contrasting models of either “extracellular
in situ
matrix mineralization” attributed to hyaline rotaliid shells, or “intracellular vesicle crystallization” attributed to porcelaneous miliolid shells. Our previous results on rotaliids along with those on miliolids in this paper question such a wide divergence of biomineralization pathways within the same phylum of Foraminifera. We found that both groups produced calcareous shells via the intravesicular formation of unstable mineral precursors (Mg-rich amorphous calcium carbonate) supplied by endocytosed seawater and deposited
in situ
as mesocrystals formed at the site of new wall formation within the organic matrix. We did not observe calcification of the needles within the transported vesicles, which challenges the previous model of miliolid mineralization. Hence, Foraminifera utilize less divergent crystallization pathways, following the recently discovered biomineralization principles. Mesocrystalline chamber walls are therefore created by accumulating and assembling particles of pre-formed liquid amorphous mineral phase within the extracellular organic matrix enclosed in a biologically controlled privileged space by active pseudopodial structures. Both calcification pathways evolved independently in the Paleozoic and are well-conserved in two clades that represent different chamber formation modes.
Chemoproteomics validates selective targeting of Plasmodium M1 alanyl aminopeptidase as a cross-species strategy to treat malaria
Authors: Creek Darren , Giannangelo Carlo , Challis Matthew , Siddiqui Ghizal , Edgar Rebecca , Malcolm Tess , Webb Chaille , Drinkwater Nyssa , Vinh Natalie , MacRaild Christopher , Counihan Natalie , Duffy Sandra , Wittlin Sergio , Devine Shane , Avery Vicky , de Koning-Ward Tania , Scammells Peter , McGowan Sheena
Published: February 2024

New antimalarial drug candidates that act via novel mechanisms are urgently needed to combat malaria drug resistance. Here, we describe the multi-omic chemical validation of
Plasmodium
M1 alanyl metalloaminopeptidase as an attractive drug target using the selective inhibitor, MIPS2673. MIPS2673 demonstrated potent inhibition of recombinant
Plasmodium falciparum
(
Pf
A-M1) and
Plasmodium vivax
(
Pv
-M1) M1 metalloaminopeptidases, with selectivity over other
Plasmodium
and human aminopeptidases, and displayed excellent
in vitro
antimalarial activity with no significant host cytotoxicity. Orthogonal label-free chemoproteomic methods based on thermal stability and limited proteolysis of whole parasite lysates revealed that MIPS2673 solely targets
Pf
A-M1 in parasites, with limited proteolysis also enabling estimation of the binding site on
Pf
A-M1 to within ~5 Å of that determined by X-ray crystallography. Finally, functional investigation by untargeted metabolomics demonstrated that MIPS2673 inhibits the key role of
Pf
A-M1 in haemoglobin digestion. Combined, our unbiased multi-omic target deconvolution strategies confirmed the on-target activity of MIPS2673, and validated selective inhibition of M1 alanyl metalloaminopeptidase as a promising multi-stage and cross-species antimalarial strategy.
Mesoscale functional organization and connectivity of color, disparity, and naturalistic texture in human second visual area
Authors: Ai Hailin , Lin Weiru , Liu Chengwen , Chen Nihong , Zhang Peng
Published: February 2024

Although parallel processing has been extensively studied in the low-level geniculostriate pathway and the high-level dorsal and ventral visual streams, less is known at the intermediate-level visual areas. In this study, we employed high-resolution fMRI at 7 Tesla to investigate the columnar and laminar organizations for color, disparity, and naturalistic texture in the human secondary visual cortex (V2), and their informational connectivity with lower and higher order visual areas. Although fMRI activations in V2 showed reproducible interdigitated color-selective thin and disparity-selective thick “stripe” columns, we found no clear evidence of columnar organization for naturalistic textures. Cortical depth-dependent analyses revealed the strongest color-selectivity in the superficial layers of V2, along with both feedforward and feedback informational connectivity with V1 and V4. Disparity selectivity was similar across different cortical depths of V2, which showed significant feedforward and feedback connectivity with V1 and V3ab. Interestingly, the selectivity for naturalistic texture was strongest in the deep layers of V2, with significant feedback connectivity from V4. Thus, while local circuitry within cortical columns is crucial for processing color and disparity information, feedback modulations from V4 play a dominant role in processing naturalistic textures in area V2.
Mesoscale functional organization and connectivity of color, disparity, and naturalistic texture in human second visual area
Authors: Ai Hailin , Lin Weiru , Liu Chengwen , Chen Nihong , Zhang Peng
Published: February 2024

Although parallel processing has been extensively studied in the low-level geniculostriate pathway and the high-level dorsal and ventral visual streams, much less is known at the intermediate-level visual areas. In this study, we employed high-resolution fMRI at 7 Tesla to investigate the columnar and laminar organizations for color, disparity, and naturalistic texture in the human secondary visual cortex (V2), and its informational connectivity with lower and higher order visual areas. Although fMRI activations in V2 showed clear and reproducible color-selective thin and disparity-selective thick “stripe” columns, we found no evidence for a columnar organization for naturalistic textures. Cortical depth-dependent analyses revealed the strongest color-selectivity in the superficial layers of V2, along with both feedforward and feedback informational connectivity with V1 and V4. Disparity selectivity was similar across different cortical depths of V2, which showed significant feedforward and feedback connectivity with V1 and V3ab. Interestingly, the selectivity for naturalistic texture was strongest in the deep layers of V2, with significant feedback connectivity from V4. Thus, while local circuitry within cortical columns is crucial for processing color and disparity information, feedback modulations from V4 play a dominant role in processing naturalistic statistics in area V2, which lacks a clear columnar organization.
Mapping responses to focal injections of bicuculline in the lateral parafacial region identifies core regions for maximal generation of active expiration
Authors: Pisanski Annette , Prostebby Mitchell , Dickson Clayton T. , Pagliardini Silvia
Published: February 2024

The lateral parafacial area (pFL) is a crucial region involved in respiratory control, particularly in generating active expiration through an expiratory oscillatory network. Active expiration involves rhythmic abdominal (ABD) muscle contractions during late-expiration, increasing ventilation during elevated respiratory demands. The precise anatomical location of the expiratory oscillator within the ventral medulla’s rostro-caudal axis is debated. While some studies point to the caudal tip of the facial nucleus (VIIc) as the oscillator’s core, others suggest more rostral areas. Our study employed bicuculline (a GABA-A receptor antagonist) injections at various pFL sites (-0.2 to +0.8mm from VIIc) to investigate the impact of GABAergic disinhibition on respiration. These injections consistently elicited ABD recruitment, but the response strength varied along the rostro-caudal zone. Remarkably, the most robust and enduring changes in tidal volume, minute ventilation and combined respiratory responses occurred at more rostral pFL locations (+0.6/+0.8 mm from VIIc). Multivariate analysis of the respiratory cycle further differentiated between locations, revealing the core site for active expiration generation. Our study advances our understanding of neural mechanisms governing active expiration and emphasizes the significance of investigating the rostral pFL region.
Human Pannexin 1 Channel is NOT Phosphorylated by Src Tyrosine Kinase at Tyr199 and Tyr309
Authors: Ruan Zheng , Lee Junuk , Li Yangyang , Du Juan , Lü Wei
Published: February 2024

Protein phosphorylation is one of the major molecular mechanisms regulating protein activity and function throughout the cell. Pannexin 1 (PANX1) is a large-pore channel permeable to ATP and other cellular metabolites. Its tyrosine phosphorylation and subsequent activation have been found to play critical roles in diverse cellular conditions, including neuronal cell death, acute inflammation, and smooth muscle contraction. Specifically, the non-receptor kinase Src has been reported to phosphorylate Tyr198 and Tyr308 of mouse PANX1 (equivalent to Tyr199 and Tyr309 of human PANX1), resulting in channel opening and ATP release. Although the Src-dependent PANX1 activation mechanism has been widely discussed in the literature, independent validation of the tyrosine phosphorylation of PANX1 has been lacking. Here, we show that commercially available antibodies against the two phosphorylation sites mentioned above—which were used to identify endogenous PANX1 phosphorylation at these two sites— are nonspecific and should not be used to interpret results related to PANX1 phosphorylation. We further provide evidence that neither tyrosine residue is a major phosphorylation site for Src kinase in heterologous expression systems. We call on the field to re-examine the existing paradigm of tyrosine phosphorylation-dependent activation of the PANX1 channel.
Temporal and spatial refugia modify predation risk for non-native crabs in rocky intertidal habitats
Authors: Montanaro Renee C. , O’Connor Nancy J.
Published: February 2024

Populations of the non-native Asian shore crab, Hemigrapsus sanguineus, now dominate the rocky intertidal of southern New England, USA. High abundances suggest the recent invader may have experienced enhanced success as a result of enemy release. While larvae and juveniles may serve as a food source for ecologically important species, little is known about predation of mature H. sanguineus or the influence of habitat on predation pressure. To assess natural predation rates of adult H. sanguineus, crabs were tethered in the intertidal at Clarks Cove in New Bedford, MA. Crabs were left in situ for half of a tidal cycle then observed for signs of predation. Results of separate high and low tide trials showed that adult crabs were preyed upon at both high and low tide, though at a significantly higher rate during high tide during both daytime and nighttime, suggesting predation by aquatic species is greater than that by terrestrial species. To investigate the role of habitat as refuge from predation, a laboratory experiment manipulated the complexity of habitat provided to crabs in the presence of a native fish predator. Results indicate better refuge is provided by more complex shelter. Together, findings suggest that fish, crabs, and/or diving birds are important predators for H. sanguineus in the invaded range and that habitat refuge acts to reduce predation pressure.
Attitude and Practice of Dental Practitioners Towards the Oral Biopsy Procedure: A Questionnaire-based Cross-sectional Study
Authors: Bhanushali Priyanka H , Prajapati Mitulkumar Rameshbhai , Bhanushali Nirali H , Shah Monali , Ranginwala Amena , Rangparia Hetal , Shah Darshak , Nayak Saurabh
Published: February 2024

Introduction: Dentists, the first medical professionals to be consulted for conditions involving the oral cavity, have the distinct advantage of being in a position to screen patients for oral cancer. To effectively manage patients, dentists must be familiar not only with where, when, how and why to perform biopsies, but also with when to refer them to specialised institutions. Aim: To assess the attitude and practice of dental practitioners towards the oral biopsy procedure. Materials and Methods: The present questionnaire-based cross-sectional study was conducted in the city of Jamnagar, Gujarat, India, from July 2023 to August 2023. Fifty dental practitioners with a minimum academic qualification of Bachelor of Dental Surgery (BDS) participated in the study, which was designed to collect information regarding the importance of oral biopsy, methods used to obtain biopsies, tissue preservation, diagnosis, referral to higher centers and the attitudes and practices of dental practitioners in examining oral mucosal lesions. The questionnaire was prepared using the Google Forms app. The received responses were compiled and statistical data (percentage) was calculated using Microsoft Excel 2020. Results: Out of total, 42 (84%) dentists encounter up to 10 oral mucosal lesions, such as potentially malignant disorders, in a month. Despite this, only 22% (n=11) of them performed biopsies themselves. Furthermore, 6 (12%) dentists did not know the proper medium for preserving biopsies. Of all, 24 (48%) dentists felt the need for proper training in biopsy techniques to be included in the undergraduate curriculum. Conclusion: Despite being aware of the importance of biopsy as a crucial diagnostic procedure, not many dentists perform it routinely due to reasons such as lack of training, patient non compliance and medicolegal implications. Hence, dentists should be educated in performing the oral biopsy procedure, including handling of specimens and referral to specialists.
The Effect of Grameen Bank Micro-Credit Granting on the Welfare of Pre-Prosperous Women in Indonesia “Case Study of PT. Permodalan Nasional Madani”
Authors: Kholishoh Machpudzoh Nur , Marselina  , Ratih Arivina
Published: February 2024

This research aims to analyze and determine the influence of Grameen Bank's credit distribution patterns on improving the welfare of underprivileged women in the form of increasing income, increasing sales, and increasing the number of workers among PT customers. Civil National Capital. This research uses primary data which was conducted using questionnaire techniques. The research method used is quantitative with SPSS analysis tools and the mean difference test. The number of samples is 120 PT customers. PNM Cirebon City/Regency. The results of this research include; Providing Grameen Bank loans has an impact on increasing sales, income and business personnel of PT's underprivileged female customers. Civil National Capital.
Architecture Design of Internet of things Virtual Laboratory
Authors: Nur Muh. Nadzirin Anshari , Purnamawati  , Amiruddin
Published: February 2024

The development of the internet today has been very developed including for the world of education, one of the technologies is the application of the Internet of Things (IoT) which should be accompanied by an increase in student competence in higher education but is currently still constrained by laboratory facilities, The purpose of this study is to produce an IoT virtual laboratory architecture design, which will then be developed into an IoT virtual lab system. The method used in this research is the waterfall method in the design and design aspects, testing is done using an expert validation instrument to determine the validity level of the virtual laboratory design before entering the implementation or system creation stage. The research has produced an IoT virtual laboratory architecture consisting of three main components, namely (1) virtualab information system, (2) virtual lab manager and (3) system integration through SCORM (Sharable Content Object Reference Model) which is used for integration into the LMS (Learning Management System) system, the results of validation from experts on the design of the IoT virtual laboratory architecture show an average score of 3.56, within the value range of 3.26 to 4.00. This indicates a very good level of quality. This indicates a very good level of quality. However, there are still areas that need to be improved, especially in criterion V2 related to the system development flow diagram which gets an average score of 3.33, so the results of this research design can be used for the system development stage.
Taxonomical Approach on Different Soil Types of Kalyana Karnataka, India
Authors: Kiranakumara  , Rudramurthy H. V.  , Basavaraj K.  , Rajesh N. L.  , Channabsavanna A. S.  , Sathishkumar U.  , Wali Vijaya
Published: February 2024

The three types of soils namely red, lateritic and black soils from Kalyana Karnataka, India, belonged to selected soil series derived from diversified geology, topography, climate and vegetation were characterized and classified based on geomorphological, morphological, physical and chemical soil properties. Red and lateritic soils series other than Badrapur, Kodambal, Rummanagunda and Kallarahatti series were classified as Typic Haplustepts while Badrapur, Kodambal, Rummanagunda and Kallarahatti series as Lithic Haplustepts at sub group level. All the black soils series other than Margutti series were keyed out as Typic Haplusterts while Margutti series as Lithic Haplusterts at subgroup level.
Demonstration of Interferometric Properties of Unbalanced Mach-Zehnder Interferometer
Authors: Ndamati Ikechi T. , Olayemi Olaoluwa S. , Madu Afam D.
Published: February 2024

This article presents a demonstration of the interferometric characteristics inherent in an unbalanced Mach-Zehnder Interferometer (MZI), implemented on a silicon-on-insulator platform through precision fabrication techniques. The investigation delves into the intricate relationship between the free spectral range (FSR) and various lengths of unbalanced MZIs. Notably, a comparison between simulation and experimental outcomes reveals a remarkable agreement.
Komodifikasi dalam Tayangan Anak di YouTube: Studi Kasus Ryan's World dan Super Duper Ziyan
Authors: Soegiarto Andrea , Irwansyah Irwansyah
Published: February 2024

Perkembangan dunia digital telah berkembang dengan pesat, termasuk perkembangan pada tayangan digital pada platform sosial media. Media sosial digunakan oleh setiap orang untuk memenuhi kebutuhannya yang berbeda-beda, seperti pemenuhan kebutuhan untuk hiburan dan informasi melalui tayangan yang ditontonnya. Berbagai jenis tayangan digital diproduksi oleh konten kreator pada berbagai platform sosial untuk memenuhi kebutuhan dan minat tiap orang yang menyaksikannya. Salah satu jenis konten yang dibuat adalah konten untuk anak-anak pada berbagai platform sosial media digital, salah satunya adalah pada platform YouTube. Beberapa konten untuk anak ini menampilkan seorang anak sebagai Kid Influencer di dalam kontennya. Beberapa channel dengan konten untuk anak ini memiliki banyak viewers maupun subscribers yang memiliki potensi untuk mendapatkan pendapatan yang besar kepada pemilik channel atau akun tersebut. Dibalik kesuksesan beberapa channel dengan target audience anak yang seorang anak sebagai Kid Influencers bisa saja dikategorikan sebagai sebuah bentuk komodifikasi anak sebagai pekerja. Dalam manuskrip ini akan dibahas praktik komodifikasi anak sebagai pekerja dalam industri budaya media digital.
Crystallographic report: tert‐Butyldifluoro(2,4,6‐tris‐iso‐propylphenyl)silane, t‐Bu(2,4,6‐i‐PrC6H2)SiF2
Authors: Pietschnig Rudolf , Belaj Ferdinand
Published: May 2004

Owing to steric congestion within the title compound, the geometry at the silicon atom deviates slightly from ideal tetrahedral geometry with an increased CSiC angle of 115.97(12)° and an elongated SiCaryl bond distance. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and radioprotective action of silathiazolidines and germathiazolidines
Authors: Célariès Benot̂ , Amourette Christine , Lion Claude , Rima Ghassoub
Published: May 2004

We report on the synthesis and characterization of new sila‐ and germa‐thiazolidines derived from 2‐[1‐(1‐naphthyl)ethyl]‐2‐imidazoline. The radioprotective activity was evaluated in mice by intraperitoneal injection. A notable diminution in the toxicity and increase in radioprotective efficacy were shown for the organometallic derivatives compared with the unsubstituted organic precursors. For some of the cyclic compounds, a delay effect was observed tranducing a slow opening in vivo of the thiazolidine ring. Copyright © 2004 John Wiley & Sons, Ltd.
Validation of a thermographic guidewire for endoluminal mapping of atherosclerotic disease: An in vitro study
Authors: Courtney Brian K. , Nakamura Mamoo , Tsugita Ross , Lilly Rick , Basisht Rachna , Grube Eberhard , Honda Yasuhiro , Yock Paul G. , Fitzgerald Peter J.
Published: May 2004

Temperature heterogeneity along the inner surface of an artery may be a surrogate marker of impending plaque rupture and has been associated with an increased likelihood of future coronary events. Initial studies using catheter‐based thermographic devices have demonstrated that the changes in temperature are subtle, while the effects of coronary flow on measured temperature have not yet been examined. A novel guidewire‐based system (ThermoCoil, Imetrx) designed to measure surface temperature in coronary arteries was used to study the effects of heat source intensity and flow on measured temperature. An in vitro model of a focal, eccentric, heat‐generating lesion demonstrated that a guidewire‐based system can detect changes in surface temperature with a precision of less than 0.08°C. In this model, temperature measurements increased linearly with source temperature and decreased with increases in flow by an exponent of −0.33 (P < 0.001 for both). Flow rates and heat source properties can significantly influence the measurement and interpretation of thermographic data. The incorporation of 2D thermographic images may contribute further to the characterization of metabolically active plaques likely to cause acute coronary syndromes. Catheter Cardiovasc Interv 2004;62:221–229. © 2004 Wiley‐Liss, Inc.
Utility of IVUS‐guided transaccess catheter in the treatment of long chronic total occlusion of the superficial femoral artery
Authors: Casserly Ivan P. , Sachar Ravish , Bajzer Christopher , Yadav Jay S.
Published: May 2004

Failure to reenter the true lumen distal to an occlusion is the most frequent cause of failure of the technique of subintimal angioplasty. We report the utility of an IVUS‐guided TransAccess catheter in overcoming this problem in the treatment of two patients with long chronic total occlusion of the superficial femoral artery. Catheter Cardiovasc Interv 2004;62:237–243. © 2004 Wiley‐Liss, Inc.
Numerical analysis of electromagnetic scattering from 3D dielectric objects using the Yasuura method
Authors: Koba Koichi , Ikuno Hiroyoshi , Kawano Mitsunori
Published: May 2004

In order to calculate 3D electromagnetic scattering problems by dielectric objects which we need to solve a large‐size simultaneous linear equation, we present a rapid algorithm on the Yasuura method where we accelerate the convergence rate of solution by using an array of multipoles as well as a conventional multipole. As a result, we can obtain the radar cross sections of dielectric objects in the optical wave region over a relatively wide frequency range and a TDG pulse response. Furtherrmore, we analyze the scattering data about dielectric objects by using the pulse responses cut by an appropriate window function in the time domain and clarify the scattering processes on dielectric objects. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(2): 39–45, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ eej.10292
Magnetic properties of TbCu7‐type Sm‐Fe‐Co‐W‐Cr system nitriding compounds
Authors: Yamamoto Hiroshi , Ooi Tetsuya
Published: May 2004

Experiments were carried out to investigate the magnetic properties of Sm‐Fe‐Co‐W‐Cr system nitriding compounds with TbCu7‐type structure. Sm10(Fe0.95−Co0.05)89.7−xW0.3Crx(x = 0 − 0.7) alloy ribbons were prepared by the single roller rapid‐quenching method, and the effects of alloy composition, and conditions of heat‐treatment and nitrogenation, were examined with regards to their magnetic properties. The optimum preparation conditions of the compounds are as follows. Composition: {Sm10(Fe0.95Co0.05)89.4W0.3Cr0.3}85.0 N15.0, roller velocity: 50 m/s, heat treatment: 675 °C × 60 min in high‐purity Ar gas, and nitriding conditions: 420 °C × 10 h in high‐purity N2 gas. Typical magnetic properties of the obtained compound powders are στ = 123.7 × 10−6 Wb · m/kg, HcJ = 706.0 kA/m, (BH)max = 139.4 kJ/m3 (17.4 MGOe), and Tc = 508 °C. It was found that this sample was an exchange spring magnet from TEM photographs and recoil loops of the hysteresis curve. The value of (BH)max for the compression molding isotropic bonded magnet prepared from the {Sm10(Fe0.95Co0.05)89.4W0.3Cr0.3}85.0 N15.0 powder is 102.9 kJ/m3 (12.9 MGOe), when the density of bonded magnet is 6.1 Mg/m3. The reversible temperature coefficient of Jτ is α(Jτ = −0.07%/°C, and the temperature coefficient of HcJ in the range of 25 °C to 125 °C obtained by a linear extrapolation is α(HcJ) = −0.44%/°C. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 148(2): 1–7, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.10339
Voltammetric Determination of α‐Tocopheryl Acetate in Pharmaceutical Dosage Forms
Authors: Michalkiewicz Slawomir , Pryciak Marzena , Malyszko Jan , Oszczudlowski Jerzy
Published: May 2004

A simple and rapid voltammetric method has been developed for the quantitative determination of α‐tocopheryl acetate (α‐TOAc) in pharmaceutical preparations. Studies with linear scan (LSV), square‐wave (SQWV) and differential pulse voltammetry (DPV) were carried out using platinum microelectrodes. A well‐defined, irreversible oxidation wave/peak was obtained at 1.30 V (vs. Ag/AgCl reference electrode.) The use of SQWV or DPV technique provides a precise determination of α‐tocopheryl acetate using the multiple standard addition method. The statistical parameters and the recovery study data clearly indicate good reproducibility and accuracy of the method. Accuracy of the results assessed by recovery trials was found within the 99.3% to 103.5%, and 99.1% to 101.4%, for SQWV and DPV, respectively. The quantification limits for the both voltammetric techniques were found to be 6×10−5 M (SQWV) and 7×10−5 M (DPV). Analysis of the authentic samples containing α‐TOAc showed no interference with common additives and excipients, such as unsaturated fatty acids (co‐formulated as glycerine esters) and vitamin A (as retinol or β‐carotene). The method proposed does not require any pretreatment of the pharmaceutical dosage forms. A gas chromatography determination of α‐TOAc in real samples was also performed for comparison.
Nucleotide sequence analysis of the recA gene and discrimination of the three isolates of urease‐positive thermophilic Campylobacter (UPTC) isolated from seagulls (Larus spp.) in Northern Ireland
Authors: Matsuda M. , Tai K. , Moore J. E. , Millar B. C. , Murayama O.
Published: May 2004

Nucleotide sequencing after TA cloning of the amplicon of the almost‐full length recA gene from three strains of UPTC (A1, A2, and A3) isolated from seagulls in Northern Ireland, the phenotypical and genotypical characteristics of which have been demonstrated to be indistinguishable, clarified nucleotide differences at three nucleotide positions among the three strains. In conclusion, the nucleotide sequences of the recA gene were found to discriminate among the three strains of UPTC, A1, A2, and A3, which are indistinguishable phenotypically and genotypically.

Thus, the present study strongly suggests that nucleotide sequence data of the amplicon of a suitable gene or region could aid in discriminating among isolates of the UPTC group, which are indis‐ tinguishable phenotypically and genotypically. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Production of lignocellulolytic enzymes by Trametes gallica and detection of polysaccharide hydrolase and laccase activities in polyacrylamide gels
Authors: Sun Xun , Zhang Renhuai , Zhang Yizheng
Published: May 2004

White rot fungus Trametes gallica was studied for the production of lignocellulolytic enzymes: cellulase, xylanase, laccase, manganese‐dependent peroxidase (MnP), and lignin peroxidase (LiP). The results demonstrated that low‐nitrogen (2.2 mM N) and surface stationary cultivation favored production of extracellular MnP. MnP activity reached 118.1 UL–1 while T. gallica was grown in a low‐nitrogen culture containing phenylalanine. However, Laccase levels observed in high‐nitrogen (22 mM N) agitated cultures were much greater than those seen in low‐nitrogen. The N source experiments seemed to reveal that NH4+ plays an important role in inducing MnP and laccase of the fungus. Results showed that T. gallica produces a series of the lignocellulolytic enzymes, and needs high N to produce all the enzymes during solid‐state fermentation of wheat straw. This paper also presents a modified zymogram procedure to detect xylanase and laccase of T. gallica in polyacrylamide gel. Xylanase in crude enzyme of T. gallica was displayed by contacting protein gel strips with xylan substrate gels and by staining with iodine. By immersing the protein gel strips in o‐tolidine solution, the blue‐green zones representing laccase activity were visualized against a colorless background. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Lengthy Rod Formation from a Poly(oxyalkylene)amine‐Intercalated Smectite Clay by a Self‐Aligning Mechanism
Authors: Lin Jiang‐Jen , Chou Chih‐Cheng , Lin Jen‐Lien
Published: May 2004

Summary: A micrometer rod morphology was produced by self‐assembly of poly(oxypropylene)amine (POP‐amine) modified montmorillonite. The requisite primary structure was prepared by intercalation of the layered clay with POP‐amine salts. During the drying process, the primary units self‐assemble into micro‐rods that are 100–800 nm wide and 2–40 μm long. The stacking process may involve two complimentary forces – the POP hydrophobic effect and the silicate ionic interaction – acting in separate directions.

Lengthy rod formation from Poly(oxyalkylene)amine‐intercalated smectite clay.

image

Lengthy rod formation from Poly(oxyalkylene)amine‐intercalated smectite clay.
Optimization of CMOS‐integrated LC oscillators using the genetic algorithm
Authors: Chiu Hung‐Wei , Chen Yu‐Chang , Lu Shey‐Shi
Published: May 2004

This paper reports on state‐of‐the‐art power‐frequency‐normalized phase noise of 21 dB, obtained from a CMOS‐integrated LC oscillator with a measured phase noise of −112 dBc/Hz at 100 kHz from the 5.3‐GHz center frequency and with power consumption of 15 mW. The excellent performance of the oscillator is attributed to the careful selection of the oscillator‐circuit parameters, which determined using the genetic algorithm. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 120–124, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20226
Multiwavelength fiber laser using a multimode elliptical‐core erbium‐doped fiber
Authors: Das Gautam , Lit John W. Y.
Published: May 2004

This paper reports on a fiber laser constructed with an erbium‐doped fiber, which has an elliptical core that is single‐moded along the minor axis and multimoded along the major axis. The laser can simultaneously emit several stable lines at room temperatures. The maximum number of lasing lines obtained depends on the number of modes supported by the erbium‐doped fiber in the cavity. The separation between the lasing lines depends on the fiber birefringence. The principle of operation is based on the anisotropic‐gain effects in a polarization‐maintaining fiber. The stability of the lasing lines, in the presence of anisotropic‐gain effects in a polarization‐maintaining fiber, has been explored. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 124–128, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20227
Design of wideband circular‐polarization filters made of chiral sculptured thin films
Authors: Chiadini Francesco , Lakhtakia Akhlesh
Published: May 2004

Cascades of chiral sculptured thin films (STFs) with successive pitches forming a geometric series are theoretically shown to function as wideband circular‐polarization filters. A simple design paradigm is provided. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 135–138, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20231
Efficient evaluation of macro‐basis‐function reaction terms in the subdomain multilevel approach
Authors: Stevanović Ivica , Mosig Juan R.
Published: May 2004

This paper presents an improved subdomain multilevel approach (SMA), a technique efficiently used for solving large complex‐shaped antennas printed in multilayered media structure. In a large electromagnetic problem, where the memory occupation and computational time have been already significantly reduced using the SMA, the calculation of the macro basis function (MBF) reaction terms remains the most time‐consuming part of the procedure. In this paper, we present an efficient way of computing MBF reaction terms and reducing them to equivalent moments. The numerical results are compared with brute‐force computations, the SMA, and the measurements. They demonstrate conclusively the efficiency and power of the new proposed technique. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 138–143, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20232
Design of an annular‐ring microstrip antenna for circular polarization
Authors: Row Jeen‐Sheen , Lin Kuang‐Woei
Published: May 2004

A new circular‐polarization (CP) design of an annular‐ring microstrip antenna operating at the fundamental TM11 mode is presented. The CP radiation of the proposed design is achieved by connecting an L‐shaped strip to two orthogonal sides of the inner boundary of the annular‐ring patch. A prototype of the proposed antenna fabricated on a foam substrate has been implemented and studied. The results show that good CP‐radiation performances are obtained and the 3‐dB axial ratio is about 2%. Good agreement is also obtained between the measured and simulated results. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 42: 156–157, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20237
Assessment of cortical gyrus and sulcus formation using magnetic resonance images in small‐for‐gestational‐age fetuses
Authors: Abe Seiji , Takagi Kenjiro , Yamamoto Tatsuo , Kato Toshinori
Published: May 2004

Objectives

The purpose was to compare the development of gyrus and sulcus formation (GSF), an indicator of brain maturation, in small‐for‐gestational‐age (SGA) fetuses using magnetic resonance (MR) imaging, with those of appropriate‐for‐gestational‐age (AGA) fetuses.

Methods

The 160 infants with a normal neurological outcome were divided into two groups on the basis of their body weight at delivery; 37 SGA infants (Group SGA) and 123 AGA infants (Group AGA). Fetal MR images, which were obtained from 28 to 39 gestational weeks in Group SGA and from 18 to 39 gestational weeks in Group AGA, were classified into the 8 stages of development for GSF established by Abe et al. (2003), and comparison was made between the two groups retrospectively in their neurological development in relation to gestational age.

Results

In Group SGA, images were classified into stages 3 to 8 (P < 0.001). The gestational age of the cases determined for each stage between Groups SGA and AGA did not differ significantly, with respect to the development of GSF, despite differences in fetal estimated body weights.

Conclusion

In SGA fetuses, evaluation of fetal GSF using MR images during the third trimester may be useful for predicting neurological prognoses postpartum. Copyright © 2004 John Wiley & Sons, Ltd.
Temperature‐dependent polymer–polymer interactions in polystyrene–polyethylene blends
Authors: Banik Indranil , Carreau Pierre J. , Schreiber Henry P.
Published: May 2004

The effect of the temperature on the interaction between the components of an immiscible polystyrene–polyethylene blend has been analyzed with different techniques. Lap‐shear‐strength data and morphological observations indicate an enhanced interaction between the polymeric phases at elevated temperatures, at which dispersive forces are known to predominate. This raises the degree of compatibility of the polymeric components. Rheological measurements also justify the concept of increased adhesion between the components of the blend when it is processed at very high temperatures. Differential scanning calorimetry analysis lends support to an improved homogeneity of the blend at an elevated temperature; this is again consistent with an improved interaction between the blend phases. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2545–2557, 2004
Dopamine D4 receptor‐deficient mice, congenic on the C57BL/6J background, are hypersensitive to amphetamine
Authors: Kruzich Paul J. , Suchland Katherine L. , Grandy David K.
Published: May 2004

Mice lacking the dopamine D4 receptor subtype (D4R−/−) are supersensitive to methamphetamine and cocaine. We sought to expand and refine earlier experiments performed on F2 generation D4R−/− mice by lengthening the behavioral session, utilizing an N10 D4R−/− incipient congenic C57BL/6J line (D4R−/− mice backcrossed with wildtype C57BL/6J mice for 10 successive generations), and investigating whether dopamine D4Rs are necessary for the expression of behavioral sensitization to amphetamine. The D4R−/− mice demonstrated an enhanced and dose‐dependent increase in amphetamine‐stimulated activity compared to wildtype mice following acute administrations of amphetamine. For the behavioral sensitization experiments, separate groups of mice received either repeated administrations of the same dose of amphetamine or a subthreshold dose of amphetamine (2 mg/kg) 28 days following pretreatment with either saline, 1.0, 3.0, or 10.0 mg/kg amphetamine. The D4R−/− mice displayed an enhanced dose‐dependent sensitized response to repeated amphetamine administrations compared to their wildtype littermates in both behavioral sensitization paradigms. Our present results further support the importance of dopamine D4Rs in psychostimulant‐mediated locomotion and neural plasticity. Synapse 53:131–139, 2004. © 2004 Wiley‐Liss, Inc.
A new approach to improved SST anomaly simulations using altimeter data: Parameterizing entrainment temperature from sea level
Authors: Zhang Rong‐Hua , Busalacchi Antonio J. , Murtugudde Raghuram G. , Hackert Eric C. , Ballabrera‐Poy Joaquim
Published: May 2004

Observed Topex/Poseidon/Jason‐1 (T/P/J) altimeter sea level (SL) data are used to improve an empirical parameterization of the temperature of subsurface water entrained into the mixed layer (Te). An inverse modeling method is first adopted to estimate Te from a SST anomaly (SSTA) equation using observed SST and simulated upper ocean currents from an intermediate ocean model (IOM). An empirical relationship between anomalies of Te (estimated) and SL (observed) from T/P/J altimeter is then constructed by utilizing a singular value decomposition (SVD) of their covariance. As compared with SSTA simulations using modeled SL data, the use of T/P/J SL data allows observed information about dynamic ocean adjustments to be built directly into the empirical Te model being used to parameterize the thermocline effect on SSTAs. The improved Te model leads to better SSTA simulations in the tropical Pacific. Cross validation is made to examine the sensitivity of the SSTA simulations to the period chosen for training the Te model. The proposed approach provides a new way to more effectively use T/P/J altimeter data in climate studies.
A self-learning coupled map lattice for vortex shedding in cable and cylinder wakes
Authors: Balasubramanian G. , Olinger D. J. , Demetriou M. A.
Published: May 2004

A coupled map lattice (CML) with self-learning features is developed to model flow over freely vibrating cables and stationary cylinders at low Reynolds numbers. Coupled map lattices that combine a series of low-dimensional circle maps with a diffusion model have been used previously to predict qualitative features of these flows. However, the simple nature of these CML models implies that there will be unmodeled wake features if a detailed, quantitative comparison is made with laboratory or simulated wake flows. Motivated by a desire to develop an improved CML model, we incorporate self-learning features into a new CML that is first trained to precisely estimate wake patterns from a target numerical simulation. A new convective–diffusive map that includes additional wake dynamics is developed. The new self-learning CML uses an adaptive estimation scheme (multivariable least-squares algorithm). Studies of this approach are conducted using wake patterns from a Navier–Stokes solution (spectral element-based NEKTAR simulation) of freely vibrating cable wakes at Reynolds numbers Re=100. It is shown that the self-learning model accurately and efficiently estimates the simulated wake patterns. The self-learning scheme is then successfully applied to vortex shedding patterns obtained from experiments on stationary cylinders. This constitutes a first step toward the use of the self-learning CML as a wake model in flow control studies of laboratory wake flows.
Analysis of ion dynamics and peak shapes for delayed extraction time-of-flight mass spectrometers
Authors: Collado V. M. , Ponciano C. R. , Fernandez-Lima F. A. , da Silveira E. F.
Published: May 2004

The dependence of time-of-flight (TOF) peak shapes on time-dependent extraction electric fields is studied theoretically. Conditions for time focusing are analyzed both analytically and numerically for double-acceleration-region TOF spectrometers. Expressions for the spectrometer mass resolution and for the critical delay time are deduced. Effects due to a leakage field in the first acceleration region are shown to be relevant under certain conditions. TOF peak shape simulations for the delayed extraction method are performed for emitted ions presenting a Maxwellian initial energy distribution. Calculations are compared to experimental results of Cs+ emission due to CsI laser ablation.
Electron-nuclear correlations for photo-induced dynamics in molecular dimers
Authors: Kilin Dmitri S. , Pereversev Yuri V. , Prezhdo Oleg V.
Published: May 2004

Ultrafast photoinduced dynamics of electronic excitation in molecular dimers is drastically affected by the dynamic reorganization of inter- and intra- molecular nuclear configuration modeled by a quantized nuclear degree of freedom [Cina et al., J. Chem Phys. 118, 46 (2003)]. The dynamics of the electronic population and nuclear coherence is analyzed by solving the chain of coupled differential equations for population inversion, electron-vibrational correlation, etc. [Prezhdo, Pereverzev, J. Chem. Phys. 113, 6557 (2000)]. Intriguing results are obtained in the approximation of a small change of the nuclear equilibrium upon photoexcitation. In the limiting case of resonance between the electronic energy gap and the frequency of the nuclear mode these results are justified by comparison to the exactly solvable Jaynes–Cummings model. It is found that the photoinduced processes in the model dimer are arranged according to their time scales: (i) Fast scale of nuclear motion, (ii) intermediate scale of dynamical redistribution of electronic population between excited states as well as growth and dynamics of electron-nuclear correlation, (iii) slow scale of electronic population approach to the quasi-equilibrium distribution, decay of electron-nuclear correlation, and decrease of the amplitude of mean coordinate oscillation. The latter processes are accompanied by a noticeable growth of the nuclear coordinate dispersion associated with the overall nuclear wave packet width. The demonstrated quantum relaxation features of the photoinduced vibronic dynamics in molecular dimers are obtained by a simple method, applicable to systems with many degrees of freedom.
Combustion process in a spark ignition engine: Dynamics and noise level estimation
Authors: Kamiński T. , Wendeker M. , Urbanowicz K. , Litak G.
Published: May 2004

We analyze the experimental time series of internal pressure in a four cylinder spark ignition engine. In our experiment, performed for different spark advance angles, apart from the usual cyclic changes of engine pressure we observed additional oscillations. These oscillations are with longer time scales ranging from one to several hundred engine cycles depending on engine working conditions. Based on the pressure time dependence we have calculated the heat released per combustion cycle. Using the time series of heat release to calculate the correlation coarse-grained entropy we estimated the noise level for internal combustion process. Our results show that for a larger spark advance angle the system is more deterministic.
Implementing quantum gates on oriented optical isomers
Authors: Sola Ignacio R. , Malinovsky Vladimir S. , Santamarı́a Jesus
Published: May 2004

Optical enantiomers are proposed to encode molecular two-qubit information processing. Using sequences of pairs of nonresonant optimally polarized pulses, different schemes to implement quantum gates, and to prepare entangled states, are described. We discuss the role of the entanglement phase and the robustness of the pulse sequences which depend on the area theorem. Finally, possible scenarios to generalize the schemes to n-qubit systems are suggested.
A subharmonic dynamical bifurcation during in vitro epileptiform activity
Authors: Perez Velazquez Jose L. , Khosravani Houman
Published: May 2004

Epileptic seizures are considered to result from a sudden change in the synchronization of firing neurons in brain neural networks. We have used an in vitro model of status epilepticus (SE) to characterize dynamical regimes underlying the observed seizure-like activity. Time intervals between spikes or bursts were used as the variable to construct first-return interpeak or interburst interval plots, for studying neuronal population activity during the transition to seizure, as well as within seizures. Return maps constructed for a brief epoch before seizures were used for approximating the local system dynamics during that time window. Analysis of the first-return maps suggests that intermittency is a dynamical regime underlying the observed epileptic activity. This type of analysis may be useful for understanding the collective dynamics of neuronal populations in the normal and pathological brain.