bluuebunny/crossref_metadata_2025 huggingface dataset:
How I treat essential thrombocythemia
Authors: Beer Philip A. , Erber Wendy N. , Campbell Peter J. , Green Anthony R.
Published: November 2010

In the past 5 years we have witnessed significant advances in both the diagnostic process and optimal therapy for patients with essential thrombocythemia (ET). Insights into the underlying molecular mechanisms have been accompanied by the development of new diagnostic tests and by an improved understanding of the relationship between ET and other related myeloproliferative neoplasms, such as polycythemia vera and primary myelofibrosis. In the first part of this review, we describe how recent molecular and histologic studies can be integrated into a streamlined diagnostic process that is applicable to everyday clinical practice. We also address areas of current diagnostic controversy, including heterogeneity within ET and the phenotypic overlap between ET, polycythemia vera, and primary myelofibrosis. In the second part, we provide an overview of our current approach to the treatment of ET, including risk stratification, choice of cytoreductive agent, and a consideration of special situations such as the pregnant or perioperative patient. Areas of controversy discussed include the identification of those at high risk of complications and therapeutic decisions in the younger patient.
Fibrinopeptides A and B release in the process of surface fibrin formation
Authors: Riedel Tomas , Suttnar Jiri , Brynda Eduard , Houska Milan , Medved Leonid , Dyr Jan E.
Published: November 2010

Fibrinogen adsorption on a surface results in the modification of its functional characteristics. Our previous studies revealed that fibrinogen adsorbs onto surfaces essentially in 2 different orientations depending on its concentration in the solution: “side-on” at low concentrations and “end-on” at high concentrations. In the present study, we analyzed the thrombin-mediated release of fibrinopeptides A and B (FpA and FpB) from fibrinogen adsorbed in these orientations, as well as from surface-bound fibrinogen-fibrin complexes prepared by converting fibrinogen adsorbed in either orientation into fibrin and subsequently adding fibrinogen. The release of fibrinopeptides from surface-adsorbed fibrinogen and from surface-bound fibrinogen-fibrin complexes differed significantly compared with that from fibrinogen in solution. The release of FpB occurred without the delay (lag phase) characteristic of its release from fibrinogen in solution. The amount of FpB released from end-on adsorbed fibrinogen and from adsorbed fibrinogen-fibrin complexes was much higher than that of FpA. FpB is known as a potent chemoattractant, so its preferential release suggests a physiological purpose in the attraction of cells to the site of injury. The N-terminal portions of fibrin β chains including residues Bβ15-42, which are exposed after cleavage of FpB, have been implicated in many processes, including angiogenesis and inflammation.
A microbial detection array (MDA) for viral and bacterial detection
Authors: Gardner Shea N , Jaing Crystal J , McLoughlin Kevin S , Slezak Tom R
Published: November 2010

Background

Identifying the bacteria and viruses present in a complex sample is useful in disease diagnostics, product safety, environmental characterization, and research. Array-based methods have proven utility to detect in a single assay at a reasonable cost any microbe from the thousands that have been sequenced.

Methods

We designed a pan-Microbial Detection Array (MDA) to detect all known viruses (including phages), bacteria and plasmids and developed a novel statistical analysis method to identify mixtures of organisms from complex samples hybridized to the array. The array has broader coverage of bacterial and viral targets and is based on more recent sequence data and more probes per target than other microbial detection/discovery arrays in the literature. Family-specific probes were selected for all sequenced viral and bacterial complete genomes, segments, and plasmids. Probes were designed to tolerate some sequence variation to enable detection of divergent species with homology to sequenced organisms, and to have no significant matches to the human genome sequence.

Results

In blinded testing on spiked samples with single or multiple viruses, the MDA was able to correctly identify species or strains. In clinical fecal, serum, and respiratory samples, the MDA was able to detect and characterize multiple viruses, phage, and bacteria in a sample to the family and species level, as confirmed by PCR.

Conclusions

The MDA can be used to identify the suite of viruses and bacteria present in complex samples.
Mutually exclusive expression of DLX2 and DLX5/6 is associated with the metastatic potential of the human breast cancer cell line MDA-MB-231
Authors: Morini Monica , Astigiano Simonetta , Gitton Yorick , Emionite Laura , Mirisola Valentina , Levi Giovanni , Barbieri Ottavia
Published: November 2010

Background

The DLX gene family encodes for homeobox transcription factors involved in the control of morphogenesis and tissue homeostasis. Their expression can be regulated by Endothelin1 (ET1), a peptide associated with breast cancer invasive phenotype. Deregulation of DLX gene expression was found in human solid tumors and hematologic malignancies. In particular, DLX4 overexpression represents a possible prognostic marker in ovarian cancer. We have investigated the role of DLX genes in human breast cancer progression.

Methods

MDA-MB-231 human breast carcinoma cells were grown in vitro or injected in nude mice, either subcutaneously, to mimic primary tumor growth, or intravenously, to mimic metastatic spreading. Expression of DLX2, DLX5 and DLX6 was assessed in cultured cells, either treated or not with ET1, tumors and metastases by RT-PCR. In situ hybridization was used to confirm DLX gene expression in primary tumors and in lung and bone metastases. The expression of DLX2 and DLX5 was evaluated in 408 primary human breast cancers examining the GSE1456 and GSE3494 microarray datasets. Kaplan-Meier estimates for disease-free survival were calculated for the patients grouped on the basis of DLX2/DLX5 expression.

Results

Before injection, or after subcutaneous growth, MDA-MB-231 cells expressed DLX2 but neither DLX5 nor DLX6. Instead, in bone and lung metastases resulting from intravenous injection we detected expression of DLX5/6 but not of DLX2, suggesting that DLX5/6 are activated during metastasis formation, and that their expression is alternative to that of DLX2. The in vitro treatment of MDA-MB-231 cells with ET1, resulted in switch from DLX2 to DLX5 expression. By data mining in microarray datasets we found that expression of DLX2 occurred in 21.6% of patients, and was significantly correlated with prolonged disease-free survival and reduced incidence of relapse. Instead, DLX5 was expressed in a small subset of cases, 2.2% of total, displaying reduced disease-free survival and high incidence of relapse which was, however, non-significantly different from the other groups due to the small size of the DLX+ cohort. In all cases, we found mutually exclusive expression of DLX2 and DLX5.

Conclusions

Our studies indicate that DLX genes are involved in human breast cancer progression, and that DLX2 and DLX5 genes might serve as prognostic markers.
Outbreak detection algorithms for seasonal disease data: a case study using ross river virus disease
Authors: Pelecanos Anita M , Ryan Peter A , Gatton Michelle L
Published: November 2010

Background

Detection of outbreaks is an important part of disease surveillance. Although many algorithms have been designed for detecting outbreaks, few have been specifically assessed against diseases that have distinct seasonal incidence patterns, such as those caused by vector-borne pathogens.

Methods

We applied five previously reported outbreak detection algorithms to Ross River virus (RRV) disease data (1991-2007) for the four local government areas (LGAs) of Brisbane, Emerald, Redland and Townsville in Queensland, Australia. The methods used were the Early Aberration Reporting System (EARS) C1, C2 and C3 methods, negative binomial cusum (NBC), historical limits method (HLM), Poisson outbreak detection (POD) method and the purely temporal SaTScan analysis. Seasonally-adjusted variants of the NBC and SaTScan methods were developed. Some of the algorithms were applied using a range of parameter values, resulting in 17 variants of the five algorithms.

Results

The 9,188 RRV disease notifications that occurred in the four selected regions over the study period showed marked seasonality, which adversely affected the performance of some of the outbreak detection algorithms. Most of the methods examined were able to detect the same major events. The exception was the seasonally-adjusted NBC methods that detected an excess of short signals. The NBC, POD and temporal SaTScan algorithms were the only methods that consistently had high true positive rates and low false positive and false negative rates across the four study areas. The timeliness of outbreak signals generated by each method was also compared but there was no consistency across outbreaks and LGAs.

Conclusions

This study has highlighted several issues associated with applying outbreak detection algorithms to seasonal disease data. In lieu of a true gold standard, a quantitative comparison is difficult and caution should be taken when interpreting the true positives, false positives, sensitivity and specificity.
Promotion of tumor development in prostate cancer by progerin
Authors: Tang Yong , Chen Yakun , Jiang Hongmei , Nie Daotai
Published: November 2010

Progerin is a truncated form of lamin A. It is identified in patients with Hutchinson-Gilford progeria syndrome (HGPS), a disease characterized by accelerated aging. The contribution of progerin toward aging has been shown to be related to increased DNA damages. Since aging is one major risk factor for carcinogenesis, and genomic instability is a hallmark of malignant cancers, we investigated the expression of progerin in human cancer cells, and whether its expression contributes to carcinogenesis. Using RT-PCR and Western blotting, we detected the expression of progerin in prostate PC-3, DU145 and LNCaP cells at mRNA and protein levels. Ectopic progerin expression did not cause cellular senescence in PC-3 or MCF7 cells. PC-3 cells progerin transfectants were sensitized to DNA damage agent camptothecin (CPT); and persistent DNA damage responses were observed, which might be caused by progerin induced defective DNA damage repair. In addition, progerin transfectants were more tumorigenic in vivo than vector control cells. Our study for the first time describes the expression of progerin in a number of human cancer cell lines and its contributory role in tumorigenesis.
The role of toll-like receptors in acute and chronic lung inflammation
Authors: Lafferty Erin I , Qureshi Salman T , Schnare Markus
Published: November 2010

By virtue of its direct contact with the environment, the lung is constantly challenged by infectious and non-infectious stimuli that necessitate a robust yet highly controlled host response coordinated by the innate and adaptive arms of the immune system. Mammalian Toll-like receptors (TLRs) function as crucial sentinels of microbial and non-infectious antigens throughout the respiratory tract and mediate host innate immunity. Selective induction of inflammatory responses to harmful environmental exposures and tolerance to innocuous antigens are required to maintain tissue homeostasis and integrity. Conversely, dysregulated innate immune responses manifest as sustained and self-perpetuating tissue damage rather than controlled tissue repair. In this article we review aspects of Toll-like receptor function that are relevant to the development of acute lung injury and chronic obstructive lung diseases as well as resistance to frequently associated microbial infections.
Mena deficiency delays tumor progression and decreases metastasis in polyoma middle-T transgenic mouse mammary tumors
Authors: Roussos Evanthia T , Wang Yarong , Wyckoff Jeffrey B , Sellers Rani S , Wang Weigang , Li Jiufeng , Pollard Jeffrey W , Gertler Frank B , Condeelis John S
Published: November 2010

Introduction

The actin binding protein Mammalian enabled (Mena), has been implicated in the metastatic progression of solid tumors in humans. Mena expression level in primary tumors is correlated with metastasis in breast, cervical, colorectal and pancreatic cancers. Cells expressing high Mena levels are part of the tumor microenvironment for metastasis (TMEM), an anatomical structure that is predictive for risk of breast cancer metastasis. Previously we have shown that forced expression of Mena adenocarcinoma cells enhances invasion and metastasis in xenograft mice. Whether Mena is required for tumor progression is still unknown. Here we report the effects of Mena deficiency on tumor progression, metastasis and on normal mammary gland development.

Methods

To investigate the role of Mena in tumor progression and metastasis, Mena deficient mice were intercrossed with mice carrying a transgene expressing the polyoma middle T oncoprotein, driven by the mouse mammary tumor virus. The progeny were investigated for the effects of Mena deficiency on tumor progression via staging of primary mammary tumors and by evaluation of morbidity. Stages of metastatic progression were investigated using an in vivo invasion assay, intravital multiphoton microscopy, circulating tumor cell burden, and lung metastases. Mammary gland development was studied in whole mount mammary glands of wild type and Mena deficient mice.

Results

Mena deficiency decreased morbidity and metastatic dissemination. Loss of Mena increased mammary tumor latency but had no affect on mammary tumor burden or histologic progression to carcinoma. Elimination of Mena also significantly decreased epidermal growth factor (EGF) induced in vivo invasion, in vivo motility, intravasation and metastasis. Non-tumor bearing mice deficient for Mena also showed defects in mammary gland terminal end bud formation and branching.

Conclusions

Deficiency of Mena decreases metastasis by slowing tumor progression and reducing tumor cell invasion and intravasation. Mena deficiency during development causes defects in invasive processes involved in mammary gland development. These findings suggest that functional intervention targeting Mena in breast cancer patients may provide a valuable treatment option to delay tumor progression and decrease invasion and metastatic spread leading to an improved prognostic outcome.
Myeloid-derived suppressor cells in the peripheral blood of cancer patients contain a subset of immature neutrophils with impaired migratory properties
Authors: Brandau Sven , Trellakis Sokratis , Bruderek Kirsten , Schmaltz Dominik , Steller Gabriele , Elian Motaz , Suttmann Henrik , Schenck Marcus , Welling Jürgen , Zabel Peter , Lang Stephan
Published: November 2010

In tumor-bearing mice, immunosuppressive granulocytic and monocytic MDSC have been identified. The identity and function of MDSC in cancer patients are less clear and need further characterization. We analyzed the peripheral blood of 103 patients with HNC, lung cancer, or cancers of bladder and ureter. Based on sedimentation properties in density gradients, a subset of LD-PMN was identified and analyzed. LD-PMN were expanded in the peripheral blood of cancer patients, suppressed proliferation, and IFN-γ production of polyclonally stimulated T cells and thus, qualify as human MDSC. Immunophenotyping and morphological analysis revealed the accumulation of immature PMN in the MDSC fraction. Neutrophilic MDSC showed altered surface marker expression, prolonged survival, and impaired effector functions when compared with conventional, mature PMN of regular density. MDSC displayed markedly reduced chemotaxis toward tumor-conditioned medium and lacked expression of chemokine receptors CXCR1 and CXCR2, which are normally required for PMN extravasation from the bloodstream and subsequent tissue infiltration. Collectively, our data suggest the accumulation and persistence of long-lived, immature granulocytic MDSC with T cell-suppressive function and impaired migratory properties in the peripheral blood of cancer patients.
Regulation of inflammation, autoimmunity, and infection immunity by HVEM-BTLA signaling
Authors: Shui Jr-Wen , Steinberg Marcos W , Kronenberg Mitchell
Published: November 2010

The HVEM, or TNFRSF14, is a membrane-bound receptor known to activate the NF-κB pathway, leading to the induction of proinflammatory and cell survival-promoting genes. HVEM binds several ligands that are capable of mediating costimulatory pathways, predominantly through its interaction with LIGHT (TNFSF14). However, it can also mediate coinhibitory effects, predominantly by interacting with IGSF members, BTLA or CD160. Therefore, it can function like a “molecular switch” for various activating or inhibitory functions. Furthermore, recent studies suggest the existence of bidirectional signaling with HVEM acting as a ligand for signaling through BTLA, which may act as a ligand in other contexts. Bidirectional signaling, together with new information indicating signaling in cis by cells that coexpress HVEM and its ligands, makes signaling within a HVEM-mediated network complicated, although potentially rich in biology. Accumulating in vivo evidence has shown that HVEM-mediated, coinhibitory signaling may be dominant over HVEM-mediated costimulatory signaling. In several disease models the absence of HVEM-BTLA signaling predominantly resulted in severe mucosal inflammation in the gut and lung, autoimmune-like disease, and impaired immunity during bacterial infection. Here, we will summarize the current view about how HVEM-BTLA signaling is involved in the regulation of mucosal inflammation, autoimmunity, and infection immunity.
Glucose-Dependent Insulinotropic Polypeptide (GIP) Induces Calcitonin Gene-Related Peptide (CGRP)-I and Procalcitonin (Pro-CT) Production in Human Adipocytes
Authors: Timper Katharina , Grisouard Jean , Radimerski Tanja , Dembinski Kaethi , Peterli Ralph , Häring Andreas , Frey Daniel M. , Zulewski Henryk , Keller Ulrich , Müller Beat , Christ-Crain Mirjam
Published: November 2010

abstract

Context:

Increased plasma levels of glucose-dependent insulinotropic polypeptide (GIP), calcitonin CT gene-related peptide (CGRP)-I, and procalcitonin (Pro-CT) are associated with obesity. Adipocytes express functional GIP receptors and the CT peptides Pro-CT and CGRP-I. However, a link between GIP and CT peptides has not been studied yet.

Objective:

The objective of the study was the assessment of the GIP effect on the expression and secretion of CGRP-I and Pro-CT in human adipocytes, CGRP-I and CT gene expression in adipose tissue (AT) from obese vs. lean subjects, and plasma levels of CGRP-I and Pro-CT after a high-fat meal in obese patients.

Design and Participants:

Human preadipocyte-derived adipocytes, differentiated in vitro, were treated with GIP. mRNA expression and protein secretion of CGRP-I and Pro-CT were measured. Human CGRP-I and CT mRNA expression in AT and CGRP-I and Pro-CT plasma concentrations were assessed.

Results:

Treatment with 1 nm GIP induced CGRP-I mRNA expression 6.9 ± 1.0-fold (P < 0.001 vs. control) after 2 h and CT gene expression 14.0 ± 1.7-fold (P < 0.001 vs. control) after 6 h. GIP stimulated CGRP-I secretion 1.7 ± 0.2-fold (P < 0.05 vs. control) after 1 h. In AT samples of obese subjects, CGRP-I mRNA expression was higher in sc AT (P < 0.05 vs. lean subjects), whereas CT expression was higher in visceral AT (P < 0.05 vs. lean subjects). CGRP-I plasma levels increased after a high-fat meal in obese patients.

Conclusion:

GIP induces CGRP-I and CT expression in human adipocytes. Therefore, elevated Pro-CT and CGRP-I levels in obesity might result from GIP-induced Pro-CT and CGRP-I release in AT and might be triggered by a high-fat diet. How these findings relate to the metabolic complications of obesity warrants further investigations.
Memantine Prevents Hypoglycemia-Induced Decrements of the Cerebral Energy Status in Healthy Subjects
Authors: Willenborg B. , Schmoller A. , Caspary J. , Melchert U. H. , Scholand-Engler H. G. , Jauch-Chara K. , Hohagen F. , Schweiger U. , Oltmanns K. M.
Published: November 2010

abstract

Context:

The risk to develop dementia is significantly increased in diabetes mellitus. Memantine, an N-methyl-d-aspartate receptor antagonist, which is clinically applied in dementia, has been shown to exert neuroprotective effects under hypoglycemic conditions in rats.

Objective:

We hypothesized that memantine may prevent hypoglycemia-induced decrements in the cerebral high-energy phosphate, i.e. ATP, metabolism to exert its neuroprotective action under these conditions.

Design and Participants:

In a randomized, double-blind crossover design, we applied memantine vs. placebo in 16 healthy male subjects and examined the cerebral high-energy phosphate metabolism by 31phosphor magnetic resonance spectroscopy, hormonal counterregulation, and neurocognitive performance during hypoglycemic glucose clamp conditions.

Results:

We found increments in hormonal counterregulation and reduced neurocognitive performance during hypoglycemia (P < 0.05). Cerebral ATP levels increased upon hypoglycemia in the memantine condition as compared with placebo (P = 0.006) and remained higher after renormalizing blood glucose concentrations (P = 0.018), which was confirmed by ATP to inorganic phosphate ratio (P = 0.046). Phosphocreatine levels and phosphocreatine to inorganic phosphate ratio remained stable throughout the experiments and did not differ between conditions (P > 0.1 for both).

Conclusion:

Our data demonstrate that memantine preserves the cerebral energy status during experimentally induced hypoglycemia in healthy subjects. An improved neuronal energy status may thus be involved in the neuroprotective effect under these conditions and may qualify memantine as potential future option to combat cognitive impairments and dementia in diabetes.
How to Construct Chiral Macrocycles from Anthracene Units and Acetylene Linkers
Authors: Toyota Shinji
Published: November 2010

We propose strategies to construct chiral macrocycles by modification of the fundamental compound, 1,8-anthrylene–ethynylene cyclic tetramer, which features a diamond-prism structure. The incorporation of other anthracene units or diacetylene linkers produces structures of various symmetries. The enantiomers of some chiral derivatives could be resolved by chiral HPLC. The structures, dynamic behavior, and chiroptical properties of these macrocycles are summarized.
Polymer Particles Incorporating ZrO2 Nanoparticles Prepared by Miniemulsion Polymerization
Authors: Tamai Toshiyuki , Watanabe Mitsuru , Minami Yuki , Okazaki Sosuke , Masuyama Araki , Matsukawa Kimihiro
Published: November 2010

Acrylic polymer particles incorporating ZrO2 nanoparticles (hybrid latex dispersion) were synthesized by miniemulsion polymerization. The refractive index of the films prepared from the hybrid latex increased with increase of ZrO2 content. Surface-modified ZrO2 nanoparticles could be dispersed in polymer matrix having phosphoric acid group.
Telemedicine-supported insulin optimisation in primary care
Authors: Larsen Mark E , Turner Jane , Farmer Andrew , Neil Andrew , Tarassenko Lionel
Published: November 2010

We investigated the feasibility of a mobile-phone based system for patients with type 2 diabetes who had recently commenced insulin therapy but remained poorly controlled. The system was evaluated in a feasibility study in a general practice setting with 23 patients over six months. A total of 22 patients successfully completed the study and used the system for a mean of 217 days (range 162–376). Blood glucose control improved, as reflected by a mean decrease in HbA1c of 0.66% ( P = 0.05), with the mean insulin dose increasing by 17 units ( P = 0.006). Blood glucose monitoring compliance was high, with readings available for 6.2 days per week, although use of the mobile phone decreased during the study. On average, the mobile phone diary was used for 3.5 days per week. Insulin dose adjustments were made throughout the study by all patients, but not as frequently as would be expected for the degree of hyperglycaemia observed.
Endovascular treatment for chronic cerebrospinal venous insufficiency: is the procedure safe?
Authors: Ludyga T , Kazibudzki M , Simka M , Hartel M , Świerad M , Piegza J , Latacz P , Sedlak L , Tochowicz M
Published: November 2010

Objectives

The aim of this report is to assess the safety of endovascular treatment for chronic cerebrospinal venous insufficiency (CCSVI). Although balloon angioplasty and stenting seem to be safe procedures, there are currently no data on the treatment of a large group of patients with this vascular pathology.

Methods

A total of 564 endovascular procedures (balloon angioplasty or, if this procedure failed, stenting) were performed during 344 interventions in 331 CCSVI patients with associated multiple sclerosis.

Results

Balloon angioplasty alone was performed in 192 cases (55.8%), whereas the stenting of at least one vein was required in the remaining 152 cases (44.2%). There were no major complications (severe bleeding, venous thrombosis, stent migration or injury to the nerves) related to the procedure, except for thrombotic occlusion of the stent in two cases (1.2% of stenting procedures) and surgical opening of femoral vein to remove angioplastic balloon in one case (0.3% of procedures). Minor complications included occasional technical problems (2.4% of procedures): difficulty removing the angioplastic balloon or problems with proper placement of stent, and other medical events (2.1% of procedures): local bleeding from the groin, minor gastrointestinal bleeding or cardiac arrhythmia.

Conclusions

The procedures appeared to be safe and well tolerated by the patients, regardless of the actual impact of the endovascular treatments for venous pathology on the clinical course of multiple sclerosis, which warrants long-term follow-up.
Liver X receptors and immune regulation
Authors: Nunomura Satoshi , Makishima Makoto , Ra Chisei
Published: November 2010

Recent studies suggest that homeostasis of lipid metabolism is crucial for the function of various immune cells. Oxygenated derivatives of cholesterol (oxysterols) are well-known regulators of lipid metabolism and have diverse functions, such as inhibition of cholesterol synthesis, efflux of intracellular cholesterol, synthesis of cholesterol esters, and activation of liver X receptors (LXRs). In this review, we introduce novel roles of the oxysterol receptors LXRs in the immune system, including regulation of inflammatory responses, T cell expansion, immunoglobulin production, and antitumor responses. We also discuss lipid-mediated signaling as a potential target for treatment of immune diseases.
Food extraction by the males of Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) from cotton leafworm larvae
Authors: Pereira Alexandre Igor de Azevedo , Ramalho Francisco de Sousa , Rodrigues Karjoene Cassimiro Vilar , Malaquias José Bruno , Souza Jefferson Virgínio da Silva , Zanuncio José Cola
Published: November 2010

In this work, the effect of different densities (1, 3, 5, 7 and 9) of 3rd instar Alabama argillacea (Huebner) larvae on food consumption by Podisus nigrispinus (Dallas) males was evaluated. The densities established were converted to weight of prey offered: 13.4 mg (one larva), 33.3 mg (three larvae), 54.3 mg (five larvae), 81.8 mg (seven larvae), and 110.34 mg (nine larvae). The quantity of food consumed by P. nigrispinus increased with the prey density. The density of preys did not affect the time spent by the predator to ingest the food. The quantity of food extracted per minute was always higher in smaller densities and lower in higher densities. Males mean body weight did not differ statistically between the treatments tested, and weight gain was smaller in the first two densities tested. Relative consumption rates increased with the quantity of larvae offered. P. nigrispinus males might change its predatory behavior as a function of the quantity of prey available.
Genetic variability of three natural populations of Maytenus aquifolium (Celesteraceae) from Telêmaco Borba, Paraná, Brazil
Authors: Sahyun Sandra Aparecida , Ruas Eduardo Augusto , Ruas Claudete de Fátima , Medri Cristiano , Souza José Roberto Pinto de , Johansson Loana Aparecida Pereira da Silva , Miranda Luíz Vicente , Ruas Paulo Maurício
Published: November 2010

Three populations of Maytenus aquifolium from Monte Alegre farm, Telemaco Borba county, Paraná, Brazil were analyzed by RAPD markers. A total of 13 primers were applied wich yielded 283 well amplified markers in all the studied populations (Mortandade, Vila Preta and Trinita), producing different values of gene diversity and polymorphic loci. The analysis of molecular variance (AMOVA) indicated that 21.77% of the genetic variation was among the population. Pairwise F ST analysis showed that the most divergent populations were closer geographically, demonstrating that other factors such as different soil types could explain this variation. Bayesian analysis for K number of clusters and the Principal Coordinate indicated that these three populations were highly structured, corroborating the high values found for the F ST and indicating that for conservation purposes all populations should be maintained.
The Impact of Perceived Prices on Willingness to Pay in Experimental Auctions
Authors: Colson Gregory , Corrigan Jay R , Rousu Matthew C.
Published: November 2010

While experimental auctions are demand revealing in theory, recent studies question whether bids fully reflect willingness to pay due to the presence of outside substitutes available in conventional markets. The presence of outside substitutes implies that bids should theoretically be censored from above at the market price. While bid price censoring has been recognized in the literature, previous research has not examined the specific dollar level at which bids should be censoredthe price at which a product can actually be purchased outside of the experimental auction or the price at which participants believe it can be purchased. We provide evidence from a field interview and experimental auction that individual-specific perceived prices differ from actual market prices. The dichotomy between perceived and true market prices is shown to have significant implications for econometric analysis of bid price data.
Infinite injective transformations whose centralizers have simple structure
Authors: Konieczny Janusz
Published: November 2010

For an infinite set X, denote by Γ(X) the semigroup of all injective mappings from X to X under function composition. For α ∈ Γ(X), let C(α) = {β ∈ g/g(X): αβ = βα} be the centralizer of α in Γ(X). The aim of this paper is to determine those elements of Γ(X) whose centralizers have simple structure. We find α ∈ (X) such that various Green's relations in C(α) coincide, characterize α ∈ Γ(X) such that the $$
\mathcal{J}
$$-classes of C(α) form a chain, and describe Green's relations in C(α) for α with so-called finite ray-cycle decomposition. If α is a permutation, we also find the structure of C(α) in terms of direct and wreath products of familiar semigroups.
Optical and microstructural properties of self-assembled InAs quantum structures in silicon
Authors: Prucnal Sławomir , Turek Marcin , Drozdziel Andrzej , Pyszniak Krzysztof , Wójtowicz Artur , Zhou Sheng-Qiang , Kanjilal Alohe , Shalimov Artem , Skorupa Wolfgang , Zuk Jerzy
Published: November 2010

The InAs quantum structures were formed in silicon by sequential ion implantation and subsequent thermal annealing. Two kinds of crystalline InAs nanostructures were successfully synthesized: nanodots (NDs) and nanopyramids (NPs). The peaks at 215 and 235 cm−1, corresponding to the transverse optical (TO) and longitudinal optical (LO) InAs single-phonon modes, respectively, are clearly visible in the Raman spectra. Moreover, the PL band at around 1.3 µm, due to light emission from InAs NDs with an average diameter 7±2 nm, was observed. The InAs NPs were found only in samples annealed for 20 ms at temperatures ranging from 1000 up to 1200°C. The crystallinity and pyramidal shape of InAs quantum structures were confirmed by HRTEM and XRD techniques. The average size of the NPs is 50 nm base and 50 nm height, and they are oriented parallel to the Si (001) planes. The lattice parameter of the NPs increases from 6.051 to 6.055 Å with the annealing temperature increasing from 1100 to 1200°C, due to lattice relaxation. Energy dispersive spectroscopy (EDS) shows almost stoichiometric composition of the InAs NPs.
Structure and physical properties of biomembranes and model membranes
Authors: Hianik T.
Published: November 2010

Structure and physical properties of biomembranes and model membranes

Biomembranes belong to the most important structures of the cell and the cell organels. They play not only structural role of the barrier separating the external and internal part of the membrane but contain also various functional molecules, like receptors, ionic channels, carriers and enzymes. The cell membrane also preserves non-equillibrium state in a cell which is crucial for maintaining its excitability and other signaling functions. The growing interest to the biomembranes is also due to their unique physical properties. From physical point of view the biomembranes, that are composed of lipid bilayer into which are incorporated integral proteins and on their surface are anchored peripheral proteins and polysaccharides, represent liquid scrystal of smectic type. The biomembranes are characterized by anisotropy of structural and physical properties. The complex structure of biomembranes makes the study of their physical properties rather difficult. Therefore several model systems that mimic the structure of biomembranes were developed. Among them the lipid monolayers at an air-water interphase, bilayer lipid membranes (BLM), supported bilayer lipid membranes (sBLM) and liposomes are most known. This work is focused on the introduction into the "physical word" of the biomembranes and their models. After introduction to the membrane structure and the history of its establishment, the physical properties of the biomembranes and their models areare stepwise presented. The most focus is on the properties of lipid monolayers, BLM, sBLM and liposomes that were most detailed studied. This contribution has tutorial character that may be usefull for undergraduate and graduate students in the area of biophysics, biochemistry, molecular biology and bioengineering, however it contains also original work of the author and his co-worker and PhD students, that may be usefull also for specialists working in the field of biomembranes and model membranes.
The finite-difference and finite-element modeling of seismic wave propagation and earthquake motion
Authors: Moczo P. , Kristek J. , Galis M. , Pazak P. , Balazovjech M.
Published: November 2010

The finite-difference and finite-element modeling of seismic wave propagation and earthquake motion
Semiconductor spintronics
Authors: Fabian Jaroslav , Matos-Abiague Alex , Ertler Christian , Stano Peter , Žutić Igor
Published: November 2010

Semiconductor spintronics

Spintronics refers commonly to phenomena in which the spin of electrons in a solid state environment plays the determining role. In a more narrow sense spintronics is an emerging research field of electronics: spintronics devices are based on a spin control of electronics, or on an electrical and optical control of spin or magnetism. While metal spintronics has already found its niche in the computer industry—giant magnetoresistance systems are used as hard disk read heads—semiconductor spintronics is yet to demonstrate its full potential. This review presents selected themes of semiconductor spintronics, introducing important concepts in spin transport, spin injection, Silsbee-Johnson spin-charge coupling, and spin-dependent tunneling, as well as spin relaxation and spin dynamics. The most fundamental spin-dependent interaction in nonmagnetic semiconductors is spin-orbit coupling. Depending on the crystal symmetries of the material, as well as on the structural properties of semiconductor based heterostructures, the spin-orbit coupling takes on different functional forms, giving a nice playground of effective spin-orbit Hamiltonians. The effective Hamiltonians for the most relevant classes of materials and heterostructures are derived here from realistic electronic band structure descriptions. Most semiconductor device systems are still theoretical concepts, waiting for experimental demonstrations. A review of selected proposed, and a few demonstrated devices is presented, with detailed description of two important classes: magnetic resonant tunnel structures and bipolar magnetic diodes and transistors. In view of the importance of ferromagnetic semiconductor materials, a brief discussion of diluted magnetic semiconductors is included. In most cases the presentation is of tutorial style, introducing the essential theoretical formalism at an accessible level, with case-study-like illustrations of actual experimental results, as well as with brief reviews of relevant recent achievements in the field.
New isotope technologies in environmental physics
Authors: Povinec P. , Betti M. , Jull A. , Vojtyla P.
Published: November 2010

New isotope technologies in environmental physics

As the levels of radionuclides observed at present in the environment are very low, high sensitive analytical systems are required for carrying out environmental investigations. We review recent progress which has been done in low-level counting techniques in both radiometrics and mass spectrometry sectors, with emphasis on underground laboratories, Monte Carlo (GEANT) simulation of background of HPGe detectors operating in various configurations, secondary ionisation mass spectrometry, and accelerator mass spectrometry. Applications of radiometrics and mass spectrometry techniques in radioecology and climate change studies are presented and discussed as well. The review should help readers in better orientation on recent developments in the field of low-level counting and spectrometry, and to advice on construction principles of underground laboratories, as well as on criteria how to choose low or high energy mass spectrometers for environmental investigations.
Top quark properties
Authors: Antoš Jaroslav
Published: November 2010

Top quark properties

There is tremendous progress in the study of top quark properties from time when the top quark was discovered by CDF and D0 collaboration in 1995 at TEVATRON collider. In this review we try to summarize results and methods how these results have been achieved. Aim is to emphasize problems and how these problems have been solved. We stay in the Standard model framework and demonstrate how the experimental results give support to this framework.
Coherent manipulations of atoms using laser light
Authors: Shore Bruce
Published: November 2010

Coherent manipulations of atoms using laser light

The internal structure of a particle - an atom or other quantum system in which the excitation energies are discrete - undergoes change when exposed to pulses of near-resonant laser light. This tutorial review presents basic concepts of quantum states, of laser radiation and of the Hilbert-space statevector that provides the theoretical portrait of probability amplitudes - the tools for quantifying quantum properties not only of individual atoms and molecules but also of artificial atoms and other quantum systems. It discusses the equations of motion that describe the laser-induced changes (coherent excitation), and gives examples of laser-pulse effects, with particular emphasis on two-state and three-state adiabatic time evolution within the rotating-wave approximation. It provides pictorial descriptions of excitation based on the Bloch equations that allow visualization of two-state excitation as motion of a three-dimensional vector (the Bloch vector). Other visualization techniques allow portrayal of more elaborate systems, particularly the Hilbert-space motion of adiabatic states subject to various pulse sequences. Various more general multilevel systems receive treatment that includes degeneracies, chains and loop linkages. The concluding sections discuss techniques for creating arbitrary pre-assigned quantum states, for manipulating them into alternative coherent superpositions and for analyzing an unknown superposition. Appendices review some basic mathematical concepts and provide further details of the theoretical formalism, including photons, pulse propagation, statistical averages, analytic solutions to the equations of motion, exact solutions of periodic Hamiltonians, and population-trapping "dark" states.
On energetic particles in space
Authors: Kudela K.
Published: November 2010

On energetic particles in space

Particles energized above the Earth's atmosphere provide unique informations about specific physical processes in the outer space. This is an attempt to present a short review of the knowledge of the characteristics of the cosmic energetic particles in wide energy range as observed on the ground, in the atmosphere, on Earth's satellites and on space probes. However, the review is related only to selected problems of cosmic ray physics and space physics. The bias is especially towards lower energies. After the historical introduction the features of primary cosmic rays is described. The heliosphere, in which the direct measurements of cosmic energetic particles takes place, is modulating the primary flux by magnetic fields controlled by the processes on solar surface and, is contributing to the low energy population by acceleration via transient processes as well as by solar flares. Important processes occur near the heliospheric outer boundary from where recently the space probes provided new information. Heliospheric influence is summarized in the third chapter. Another important object, the magnetosphere, is changing trajectories of incoming charged particles by "magnetospheric optics". Magnetosphere iself by the acceleration, transport, trapping as well as losses of lower energy particles alternates significantly the radiation environment near the Earth. The knowledge of particle population for which the condition of trapping are suitable in magnetospheres of giant planets of solar system, have increased thanks to space probes and planetary orbiters. Chapter four summarizes few important points of the magnetospheric influence on energetic particles. The measurements of temporal variability of the flux, energy spectra and angular distribution of cosmic ray particles influenced by solar-terrestrial effects, provides a unique tool for monitoring and eventual prediction of space weather effects, in addition to the investigations of the photon flux of various wavelength from the Sun, solar wind plasma and the magnetic field in interplanetary space. This is the main part of the chapter five.
In vitro Plant Regeneration from Axillary Buds of Asparagus racemosus Wild, a Medicinal Plant
Authors: Afroz F , Jahan MAA , Hassan AKM Sayeed , Khatun R
Published: November 2010

An efficient method was developed for regeneration of Asparagus racemosus Wild, from axillary explants. MS media supplemented with different concentrations of cytokinin (BAP) alone or in combination of different concentrations of auxin (NAA or IBA) was tested for their efficiency in multiple shoot induction. High frequency of multiple shoot regeneration was achieved on MS medium supplemented with BAP (0.1mg/l) and NAA (0.05 mg/l). When shoots were well developed they were dissected and subcultured on the same medium to promote more multiple shoots. Eighteen to twenty shoots were obtained on this medium. The shoots were rooted best on half MS medium supplemented with 0.05 mg/l BAP and 1.0 mg/l IBA. Among the five levels of pH tested, 5.7 was the best for multiple shoot proliferation. The result presented here proved to be suitable for the rapid propagation system of A. racemosus. Key words: Asparagus racemosus; Medicinal plant; Rapid proliferation; Multiple shoots; Auxins and Cytokinins DOI: 10.3329/bjsir.v45i3.6534Bangladesh J. Sci. Ind. Res. 45(3), 255-260, 2010
Bioactivity of Marine Organisms: Part XI- Screening of some Marine Flora from the Indian Coasts
Authors: Lakshmi V , Goel AK , Srivastava MN , Raghubir R
Published: November 2010

With a view to explore of finding the new molecules with therepeutic efficacy for human use, the alcoholic extracts of 33 indentified species of marine flora, collected from Indian coasts, were prepared and screened for a wide range of biological activities. Of these, 1 extract showed antifilarial activity, 1 showed antiamoebic effect and the 1 showed antitrichomonas activity. Key words: Marine flora; Ethanol extracts; Broad biological screening; 3 active extracts. DOI: 10.3329/bjsir.v45i3.6537Bangladesh J. Sci. Ind. Res. 45(3), 271-276, 2010
Phase-Segregated Dendrigraft Copolymer Architectures
Authors: Cadena Lorena-Eugenia Sanchez , Gauthier Mario
Published: November 2010

Dendrigraft polymers have a multi-level branched architecture resulting from the covalent assembly of macromolecular building blocks. Most of these materials are obtained in divergent (core-first) synthetic procedures whereby the molecule grows outwards in successive grafting reactions or generations. Two main types of dendrigraft polymers can be identified depending on the distribution of reactive sites over the grafting substrate: Arborescent polymers have a large and variable number of more or less uniformly distributed sites, while dendrimer-like star polymers have a lower but well-defined number of grafting sites strictly located at the ends of the substrate chains. An overview of the synthesis and the characterization of dendrigraft copolymers with phase-segregated morphologies is provided in this review for both dendrigraft polymer families. The tethering of side-chains with a different composition onto branched substrates confers unusual physical properties to these copolymers, which are highlighted through selected examples.
Hantaviruses in the Americas and Their Role as Emerging Pathogens
Authors: Hjelle Brian , Torres-Pérez Fernando
Published: November 2010

The continued emergence and re-emergence of pathogens represent an ongoing, sometimes major, threat to populations. Hantaviruses (family Bunyaviridae) and their associated human diseases were considered to be confined to Eurasia, but the occurrence of an outbreak in 1993–94 in the southwestern United States led to a great increase in their study among virologists worldwide. Well over 40 hantaviral genotypes have been described, the large majority since 1993, and nearly half of them pathogenic for humans. Hantaviruses cause persistent infections in their reservoir hosts, and in the Americas, human disease is manifest as a cardiopulmonary compromise, hantavirus cardiopulmonary syndrome (HCPS), with case-fatality ratios, for the most common viral serotypes, between 30% and 40%. Habitat disturbance and larger-scale ecological disturbances, perhaps including climate change, are among the factors that may have increased the human caseload of HCPS between 1993 and the present. We consider here the features that influence the structure of host population dynamics that may lead to viral outbreaks, as well as the macromolecular determinants of hantaviruses that have been regarded as having potential contribution to pathogenicity.