bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-efficiency inverse class-F power amplifier using 3/4 spiral symmetric defected ground structure
Authors: Jin Shilei , Zhou Jianyi , Zhang Lei 
Published: July 2011

In this article, the development of a high-efficiency power amplifier (PA) with the inverse class-F configuration and a novel 3/4 spiral defected ground structure (DGS) is presented. The proposed DGS structure has improved rejection characteristic and its resonance frequencies are more convenient to adjust than conventional symmetric and asymmetric spiral structure. The electromagnetic-simulated result shows that the proposed circuit has improved harmonic control performance with simplified structure and less return loss than the conventional microstrip harmonic control circuit. The 3/4 spiral harmonics control circuit (HCC) can be modeled by three parallel RLC resonators. Using the proposed structure a high-performance harmonic control circuit is designed for implementing an inverse class-F PA. For comparison, two inverse class-F PAs operating at 2.4 GHz have been implemented by the microstrip HCC and the proposed HCC, respectively. According to the experiment results, the size of the proposed inverse class-F PA is reduced by 20%, the power-added efficiency and the gain are increased by 4.8% and 1.5 dB, respectively.
The Evolution of a Teacher and Collaborator Extraordinaire: An Interview with Virginia A. Andreoli Mathie
Authors: Giordano Peter J. 
Published: July 2011

Virginia Andreoli Mathie received her BMath and BA from the University of Waterloo and her MA and PhD in social psychology from the University of North Carolina–Chapel Hill. She taught at James Madison University (JMU) for 29 years. In July 2004 she became Executive Director of Psi Chi, the National Honor Society in Psychology. She has held several prominent leadership positions in psychology including secretary of the Virginia Psychological Association, president of the Virginia Academy of Academic Psychologists, president of the Society for the Teaching of Psychology, member of the American Psychological Association's (APA) Board of Educational Affairs, and chair of the APA Psychology Partnerships Project (P3). She has been a Harry Kirke Wolfe Lecturer, received an APA Presidential Citation for her leadership of P3, and received the 2002 APA Distinguished Contributions to Applications of Psychology to Education and Training Award. Peter J. Giordano is Professor and Chair of the Psychology Department at Belmont University in Nashville, TN, where he began his career in 1989. He received his BA in psychology and MA and PhD in clinical psychology from the University of North Carolina–Chapel Hill. A Fellow of Division 2 of APA, he was National President of Psi Chi in 2001–2002 and served as the Methods and Techniques Editor for Teaching of Psychology from 1999 to 2002.
Optimal expansions in non-integer bases
Authors: Dajani Karma , de Vries Martijn , Komornik Vilmos , Loreti Paola 
Published: July 2011

For a given positive integer

m
m

, let

A
=
{
0
,
1
,
…
,
m
}

A=\{0,1,\ldots ,m\}

and

q
∈
(
m
,
m
+
1
)

q \in (m,m+1)

. A sequence

(

c
i

)
=

c
1

c
2

…

(c_i)=c_1c_2 \ldots

consisting of elements in

A
A

is called an expansion of

x
x

if

∑

i
=
1

∞

c
i

q

−
i

=
x

\sum _{i=1}^{\infty } c_i q^{-i}=x

. It is known that almost every

x
x

belonging to the interval

[
0
,
m

/

(
q
−
1
)
]

[0,m/(q-1)]

has uncountably many expansions. In this paper we study the existence of expansions

(

d
i

)

(d_i)

of

x
x

satisfying the inequalities

∑

i
=
1

n

d
i

q

−
i

≥

∑

i
=
1

n

c
i

q

−
i

\sum _{i=1}^n d_iq^{-i} \ge \sum _{i=1}^n c_i q^{-i}

,

n
=
1
,
2
,
…
,

n=1,2,\ldots ,

for each expansion

(

c
i

)

(c_i)

of

x
x

.
Immersion Freezing of Cell Monolayers for Cryo-Electron Tomography
Authors: Resch Guenter P. , Brandstetter Marlene , Wonesch Veronika I. , Urban Edit 
Published: July 2011

INTRODUCTIONCryo-transmission electron microscopy (cryo-TEM) is not limited to the visualization of suspended macromolecules in their native hydrated state. It can also be used to elucidate the molecular architecture of peripheral parts of adherent cells: After cultivation of the cells directly on EM grids, they are physically fixed by immersion freezing to yield cells embedded in thin, crystal-free layers of frozen water. Subsequently, specimens can be visualized using cryo-electron tomography (cryo-ET). This protocol outlines the production of protein-coated gold particles as suitable fiducial markers for electron tomography, and how to cultivate cells on grids with a carbon support film. It also describes how to freeze cells to obtain optimal and reproducible results using the Leica EM GP immersion freezer, and how to assess the results.
Using Intravital Dyes to Ubiquitously Label Embryonic Zebrafish
Authors: Godinho Leanne 
Published: July 2011

INTRODUCTIONIn the last two decades, the small tropical freshwater-dwelling zebrafish has emerged as a popular model for developmental biologists. The exceptional optical accessibility of zebrafish embryos coupled with the ability to use genetic tools to indelibly tag cells have been exploited to watch developmental events as they unfold. Moreover, because zebrafish are vertebrates, the knowledge gained through such studies is broadly applicable. This protocol describes the use of intravital dyes to ubiquitously label embryonic zebrafish. Intravital dyes such as CellTrace BODIPY TR methyl ester can be used to counterstain embryos that express fluorescent proteins either through transient injections or by stable transgenics. BODIPY TR should only be used in combination with fluorescent proteins that can be spectrally separated from it. The BODIPY TR absorption spectrum peaks at 598 nm, and its emission spectrum peaks at 625 nm. Embryos should be stained just before imaging.
CCD Cameras for Fluorescence Imaging of Living Cells
Authors: Salmon Wendy C. , Waters Jennifer C. 
Published: July 2011

INTRODUCTIONCharged-coupled device (CCD) cameras are commonly used to acquire wide-field, spinning-disk confocal, and total internal reflection fluorescence (TIRF) microscopy images. Collecting digital images for a live cell fluorescence microscopy experiment requires balancing the desire to acquire sufficiently high-quality images with the need to minimize exposure of the specimen to light to reduce phototoxicity and photobleaching. The choice of CCD camera and the camera acquisition settings are critical determinants in the quality of a digital image that one can acquire from a given fluorescent specimen. In this article, we discuss the characteristics of CCD cameras, how they affect digital-image quality, and how to properly use a CCD camera for fluorescence live cell imaging experiments.
Generating and Imaging Multicolor Brainbow Mice
Authors: Weissman Tamily A. , Sanes Joshua R. , Lichtman Jeff W. , Livet Jean 
Published: July 2011

INTRODUCTIONVisualizing the precise morphology of closely juxtaposed cells and their interactions can be highly informative, particularly when studying the complex organization of neuronal and glial networks in the nervous system. To this end, one can use optical approaches to image-distinct markers that are differentially distributed among the cells of interest, such as fluorescent proteins of various colors (XFPs). The Brainbow strategies use Cre/lox recombination to stochastically express two to four XFPs in a cellular population from a single promoter. Integration of multiple Brainbow transgene copies results in combinatorial expression of these XFPs, creating a wide range of hues. In the nervous system, the multicolor labeling thus generated can be used to distinguish adjacent neuronal or glial cells and to verify the identity of neuronal processes while tracing circuitry. This article describes the generation of Brainbow transgenes and mice as well as their use to image and digitally reconstruct nerve cells and their interactions in fixed samples. This method also holds potential for studies in other tissues and model organisms as well as live imaging in vivo.
Imaging the Dynamics of Biological Processes via Fast Confocal Microscopy and Image Processing
Authors: Liebling Michael 
Published: July 2011

INTRODUCTIONConfocal microscopy offers the ability to optically section biological samples and to build three-dimensional (3D) volumes that can be digitally rendered, viewed from arbitrary directions, and quantitatively analyzed. Capturing, in addition to their 3D structure, the dynamics of living cells and organisms, further requires that image acquisition be performed rapidly to avoid measurements that are corrupted by sample movement. Several variations of the confocal principle have been incorporated into microscopes that can achieve fine optical sectioning, high frame rate, and high signal-to-noise ratio (SNR), while minimally perturbing biological samples. In this article we present some of the challenges and the requirements that are tied to imaging live samples and discuss how these are addressed by three optical versions of fast confocal microscopes: single-beam point scanning, spinning-disk, and slit-scanning confocal microscopes. Finally, we show that, for samples undergoing periodic motions, dynamic 3D image representations with virtually identical frame rates as in the case of two-dimensional (2D) imaging can be achieved via postacquisition image synchronization. These tools and techniques open new avenues for imaging fast dynamic processes in biology.
Analysis of Cytokinin Mutants and Regulation of Cytokinin Metabolic Genes Reveals Important Regulatory Roles of Cytokinins in Drought, Salt and Abscisic Acid Responses, and Abscisic Acid Biosynthesis
Authors: Nishiyama Rie , Watanabe Yasuko , Fujita Yasunari , Le Dung Tien , Kojima Mikiko , Werner Tomás , Vankova Radomira , Yamaguchi-Shinozaki Kazuko , Shinozaki Kazuo , Kakimoto Tatsuo , Sakakibara Hitoshi , Schmülling Thomas , Tran Lam-Son Phan 
Published: July 2011

Abstract
Cytokinins (CKs) regulate plant growth and development via a complex network of CK signaling. Here, we perform functional analyses with CK-deficient plants to provide direct evidence that CKs negatively regulate salt and drought stress signaling. All CK-deficient plants with reduced levels of various CKs exhibited a strong stress-tolerant phenotype that was associated with increased cell membrane integrity and abscisic acid (ABA) hypersensitivity rather than stomatal density and ABA-mediated stomatal closure. Expression of the Arabidopsis thaliana ISOPENTENYL-TRANSFERASE genes involved in the biosynthesis of bioactive CKs and the majority of the Arabidopsis CYTOKININ OXIDASES/DEHYDROGENASES genes was repressed by stress and ABA treatments, leading to a decrease in biologically active CK contents. These results demonstrate a novel mechanism for survival under abiotic stress conditions via the homeostatic regulation of steady state CK levels. Additionally, under normal conditions, although CK deficiency increased the sensitivity of plants to exogenous ABA, it caused a downregulation of key ABA biosynthetic genes, leading to a significant reduction in endogenous ABA levels in CK-deficient plants relative to the wild type. Taken together, this study provides direct evidence that mutual regulation mechanisms exist between the CK and ABA metabolism and signals underlying different processes regulating plant adaptation to stressors as well as plant growth and development.
Cytoskeletal and membrane remodelling during malaria parasite invasion of the human erythrocyte
Authors: Zuccala Elizabeth S. , Baum Jake 
Published: July 2011

SummaryErythrocytes are remarkably dynamic structures, possessing multiple and complex pathways for regulating cell membrane properties to compensate for the absence of a nucleus and internal membranes. Unlike the invasion strategies of many viruses and bacteria into their eukaryotic hosts, however, the accepted model for malaria parasite entry into human erythrocytes casts the host cell in a largely passive role. This is in contrast to mounting evidence for a suite of dynamic alterations that the erythrocyte membrane undergoes during the rapid process of invasion by the blood stage malaria parasite – the merozoite. Here we review the cellular and molecular basis for merozoite invasion of the erythrocyte and explore the idea that radical changes in the erythrocyte membrane protein and lipid architecture probably accompany this key step in the establishment of human malaria disease.
Diagnosis of Burkitt lymphoma using an algorithmic approach – applicable in both resource‐poor and resource‐rich countries
Authors: Naresh Kikkeri N. , Ibrahim Hazem A. H. , Lazzi Stefano , Rince Patricia , Onorati Monica , Ambrosio Maria R. , Bilhou‐Nabera Chrystèle , Amen Furrat , Reid Alistair , Mawanda Michael , Calbi Valeria , Ogwang Martin , Rogena Emily , Byakika Bessie , Sayed Shahin , Moshi Emma , Mwakigonja Amos , Raphael Martine , Magrath Ian , Leoncini Lorenzo 
Published: July 2011

SummaryDistinguishing Burkitt lymphoma (BL) from B cell lymphoma, unclassifiable with features intermediate between diffuse large B‐cell lymphoma (DLBCL) and BL (DLBCL/BL), and DLBCL is challenging. We propose an immunohistochemistry and fluorescent in situ hybridization (FISH) based scoring system that is employed in three phases – Phase 1 (morphology with CD10 and BCL2 immunostains), Phase 2 (CD38, CD44 and Ki‐67 immunostains) and Phase 3 (FISH on paraffin sections for MYC, BCL2, BCL6 and immunoglobulin family genes). The system was evaluated on 252 aggressive B‐cell lymphomas from Europe and from sub‐Saharan Africa. Using the algorithm, we determined a specific diagnosis of BL or not‐BL in 82%, 92% and 95% cases at Phases 1, 2 and 3, respectively. In 3·4% cases, the algorithm was not completely applicable due to technical reasons. Overall, this approach led to a specific diagnosis of BL in 122 cases and to a specific diagnosis of either DLBCL or DLBCL/BL in 94% of cases that were not diagnosed as BL. We also evaluated the scoring system on 27 cases of BL confirmed on gene expression/microRNA expression profiling. Phase 1 of our scoring system led to a diagnosis of BL in 100% of these cases.
Central cervical lymph node metastases in papillary thyroid cancer: a systematic review of imaging‐guided and prophylactic removal of the central compartment
Authors: Mulla Mubashir , Schulte Klaus‐Martin 
Published: July 2011

SummaryBackground  Papillary thyroid cancer (PTC) is a common endocrine cancer and commonly presents with lymph node (LN) metastases. The role of surgical removal of the central cervical LN compartment is poorly defined. There are no prospective randomized controlled trials addressing the relevance to the extent of the initial surgical approach.Design and Methods  A systematic review of studies of patients with PTC undergoing either prophylactic or therapeutic lymphadenectomy of the central LNs was carried out. Studies involving imaging modalities in the detection of LNs in PTC were also analysed.Results  Twenty‐one studies contained data on 4188 patients undergoing prophylactic or imaging‐guided removal of the central compartment. Imaging‐guided surgery retrieved cancerous central LNs in 346 or 30% of eligible patients, whilst prophylactic central neck dissection yielded histopathological proof of cancer in 898 or 26·2% of patients. Five imaging studies revealed data on the use of ultrasound (US) and/or computerized tomography (CT). The sensitivity of US and CT was poor, ranging from 50% to 70% when accurately calculated.Conclusion  Metastatic central LNs are found in nearly half of all patients with PTC when prophylactic central lymph node dissection (CLND) is performed. With unreliable imaging modalities, prophylactic CLND should be performed on all patients with PTC.
Adenoma granulation pattern correlates with clinical variables and effect of somatostatin analogue treatment in a large series of patients with acromegaly
Authors: Fougner Stine Lyngvi , Casar‐Borota Olivera , Heck Ansgar , Berg Jens Petter , Bollerslev Jens 
Published: July 2011

SummaryContext  Somatotroph adenomas have been classified into densely granulated (DG) and sparsely granulated (SG) tumours with a transitional, intermediate group. Gsp oncogenes are activating mutations in the Gsα subunit gene, found in approximately 40% of somatotroph adenomas.Objectives  To explore granulation pattern and presence of gsp oncogene in acromegaly with correlations to clinical and biochemical variables and to the effect of treatment with somatostatin analogues (SA), as well as to describe granulation pattern in adenomas with and without SA pretreatment.Design/settings/patients  Seventy‐eight patients with active acromegaly were included. Long‐term SA efficacy was evaluated in 29 patients treated preoperatively and in ten treated postoperatively. Granulation pattern was examined, as were immunohistochemical analyses for E‐cadherin and SSTR2a. Protein levels of E‐cadherin and SSTR2a were measured (Western blot). Gsp mutation analysis was available for 74 adenomas.Results  DG adenomas and the transitional group had higher serum levels of IGF‐1 per tumour volume than SG (P = 0·009; P = 0·005). Acute and long‐term SA responses were lower in SG (P = 0·001; P = 0·043). No correlation between gsp mutation and granulation was found, and no difference in granulation pattern according to preoperative SA treatment was demonstrated. A significant correlation between granulation and E‐cadherin was found, where SG had lowest immunohistochemical expression, substantiated by protein levels, and a highly significant gradient was observed from DG, through the transitional group, to SG.Conclusions  Densely granulated adenomas were highly responsive to somatostatin analogues in contrast to SG adenomas. The transitional group behaved clinically more like DG adenomas. However, based on E‐cadherin, a marker of dedifferentiation, the transitional group seemed to be a true intermediate.
The lack of reproducibility of different distillation techniques and its impact on pear spirit composition
Authors: García‐Llobodanin Laura , Roca Jordi , López José Ramón , Pérez‐Correa José Ricardo , López Francisco 
Published: July 2011

SummaryWe analysed the impact of operation variability on the composition of pear spirits obtained with a Charentais alembic and a packed distillation column. Lack of reproducibility significantly affected the spirits’ compositions, with batch distillation columns more difficult to operate reproducibly vs. traditional alembics. The composition of column distilled spirits differed more in esters, such as ethyl octanoate, ethyl decanoate and ethyl palmitate. In turn, alembic spirit compositions differed more in acetaldehyde and acetal. Moreover, column distilled spirits contained four times more esters, 20% more higher alcohols, 40% less acetaldehyde and 10% less methanol than alembic spirits. Spirits distilled with a rectification column were more concentrated in ethanol than alembic distilled spirits, although both distillation systems recovered the same amount of ethanol in the heart fraction.
The role of transient dynamics in biological pest control: insights from a host–parasitoid community
Authors: Kidd David , Amarasekare Priyanga 
Published: July 2011

Summary1.Identifying natural enemies that can maintain pests at low abundances is a priority in biological control. Here, we show that experiments combined with models generate new insights into identifying effective control agents prior to their release in the field. Using a host–parasitoid community (the harlequin bug and its egg parasitoids) as a model system, we report three key findings.2.The interplay between the host's self‐limitation and the parasitoids’ saturating functional response causes the long‐term (steady‐state) outcomes for pest suppression to differ from those of short‐term (transient) dynamics. When the bug's self‐limitation is moderately strong, the parasitoid with the higher attack rate and conversion efficiency (Ooencyrtus) achieves greater host suppression in the long term, but its longer handling time causes long periods of transient dynamics during which the bug can reach high abundances; when the bug's self‐limitation is weak, host fluctuations amplify over time andOoencyrtusfails at host suppression altogether. In contrast, the parasitoid with the lower attack rate and conversion efficiency but the shorter handling time (Trissolcus) induces only weak transient fluctuations of short duration and can maintain the host at low abundances regardless of the strength of the bug's self‐limitation.3.Release of multiple enemy species can compromise host suppression if an enemy that induces stronger transient fluctuations excludes one that induces weaker fluctuations. For instance,Ooencyrtusexcludes Trissolcus despite having a longer handling time because of its higher conversion efficiency. The model correctly predicts the time to exclusion observed in experiments, suggesting that it captures the key biological features of the host–parasitoid interaction.4.Intraspecific interference reduces long‐term pest suppression but improves short‐term pest control by reducing the magnitude and duration of transient fluctuations.5.These results highlight the importance of transient dynamics in pest suppression. Pests are unlikely to be strongly self‐limited because they attack crop monocultures. Hence, pest fluctuations are likely to dominate short‐term dynamics even when the long‐term outcome is a stable equilibrium. The tendency to induce strong transient fluctuations (e.g. through a long handling time) is therefore a crucial consideration when identifying effective pest control agents.