bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification of Fine Powders by a Superconducting HGMS With Vibration Assistance
Authors: Wang Yanmin , Johansson Ann-Cathrine , Forssberg Eric , Chan Billy
Published: September 2007

In this study, a superconducting high gradient magnetic separator (HGMS) with a
matrix vibration system in dry mode was utilised to purify fine calcite and quartz
powders smaller than 38 µm. The effects of the operating parameters (particle size,
magnetic field/average air velocity (Bo /Vo), the amplitude of vibration as well as the aperture size of the expanded metal matrix) have been presented. The mechanicallybased matrix vibration with the air blowing was recognised to be effective for dry
purification of fine powdered materials at high magnetic fields. The function of the
matrix vibration has been discussed. In addition, the results have been empirically
correlated with the operating parameters used for the purification in the separator.
Comparison of Magnetic Separation and Flotation Results for Beneficiation of Emet Colemanite Ores
Authors: Ozkan S. G.
Published: September 2007

Colemanite (2CaO 3B2O3 5H2O) is one of the commercially preferable borates for many industries, such as agricultural, metallurgical, nuclear and production of fibreglass, borosilicate glasses, soaps, detergents, fire retardants, enamels and frits, used directly or after being transformed to boric acid (H3BO3). This paper aims mainly to investigate the practical floatability of colemanite from the Emet deposits of Turkey using a
conventional collector and to compare the concentration results with dry magnetic
separation tests applied at high intensity.
Suppression of Peroxisomal Enzyme Activities and Cytochrome P450 4A Isozyme Expression by Congeneric Polybrominated and Polychlorinated Biphenyls
Authors: Robertson Larry W. , Berberian Isabelle , Borges Tim , Chen Li-Chuan , Chow Ching K. , Glauert Howard P. , Filser Johannes G. , Thomas Helmut
Published: September 2007

The purpose of this study was to determine the effects of PCBs and PBBs on peroxisome proliferator-activated receptor-α-(PPARα-) associated enzyme activities or protein levels. Male Sprague-Dawley rats were administered a single IP injection (150 μmol/kg) of either 3,3′,4,4′-tetrabromobiphenyl, 3,3′,4,4′-tetrachlorobiphenyl, 3,3′,5,5′-tetrabromobiphenyl, 2′,3,3′,4,5-pentachlorobiphenyl, 3,3′,4,4′,5-pentachlorobiphenyl, 2,2′,3,3′,5,5′-hexachlorobiphenyl, or 3,3′,4,4′,5,5′-hexabromobiphenyl in corn oil (10 ml/kg). One week later, the activities of catalase, peroxisomal fatty acyl-CoA oxidase, and peroxisomal beta-oxidation as well as cytochrome P450 4A (CYP4A) protein content were determined in subcellular liver fractions. None of the peroxisomal enzyme activities were significantly increased by any of the halogenated biphenyl congeners tested. Except for minor (approx. 25%) increases in the total CYP4A content following treatment with 2,2′,3,3′,5,5′-hexachlorobiphenyl and 3,3′,5,5′-tetrabromobiphenyl, CYP4A protein contents were not increased by any treatment. The two Ah receptor agonists, 3,3′,4,4′-tetrabromobiphenyl and 3,3′,4,4′,5-pentachlorobiphenyl, significantly diminished the liver content of CYP4A proteins and activities of the peroxisomal enzymes studied. Since a range of congeners with different biologic and toxicologic activities were selected for this study, it may be concluded that the polyhalogenated biphenyls do not induce peroxisome proliferation in the male rat, but rather certain members of this class of compounds down regulate peroxisome-associated enzymes. Since PCBs and PBBs do not increase enzyme activities and expression of proteins associated with PPARα, these agents are therefore exerting their carcinogenic and promoting activities by some other mechanism.
Significant Comparative Characteristics between Orphan and Nonorphan Genes in the Rice (Oryza sativa L.) Genome
Authors: Guo Wen-Jiu , Li Ping , Ling Jun , Ye Shao-Ping
Published: September 2007

Microsatellites are short tandem repeats of one to six bases in genomic DNA. As microsatellites are highly polymorphic and play a vital role in gene function and recombination, they are an attractive subject for research in evolution and in the genetics and breeding of animals and plants. Orphan genes have no known homologs in existing databases. Using bioinformatic computation and statistical analysis, we identified 19,26 orphan genes in the rice (Oryza sativa ssp. Japanica cv. Nipponbare) proteome. We found that a larger proportion of orphan genes are expressed after sexual maturation and under environmental pressure than nonorphan genes. Orphan genes generally have shorter protein lengths and intron size, and are faster evolving. Additionally, orphan genes have fewer PROSITE patterns with larger pattern sizes than those in nonorphan genes. The average microsatellite content and the percentage of trinucleotide repeats in orphan genes are also significantly higher than in nonorphan genes. Microsatellites are found less often in PROSITE patterns in orphan genes. Taken together, these orphan gene characteristics suggest that microsatellites play an important role in orphan gene evolution and expression.
EEG-Based Brain-Computer Interface for Tetraplegics
Authors: Kauhanen Laura , Jylänki Pasi , Lehtonen Janne , Rantanen Pekka , Alaranta Hannu , Sams Mikko
Published: September 2007

Movement-disabled persons typically require a long practice time to learn how to use a brain-computer interface (BCI). Our aim was to develop a BCI which tetraplegic subjects could control only in 30 minutes. Six such subjects (level of injury C4-C5) operated a 6-channel EEG BCI. The task was to move a circle from the centre of the computer screen to its right or left side by attempting visually triggered right- or left-hand movements. During the training periods, the classifier was adapted to the user's EEG activity after each movement attempt in a supervised manner. Feedback of the performance was given immediately after starting the BCI use. Within the time limit, three subjects learned to control the BCI. We believe that fast initial learning is an important factor that increases motivation and willingness to use BCIs. We have previously tested a similar single-trial classification approach in healthy subjects. Our new results show that methods developed and tested with healthy subjects do not necessarily work as well as with motor-disabled patients. Therefore, it is important to use motor-disabled persons as subjects in BCI development.
A Measurement Study of the Structured Overlay Network in P2P File-Sharing Systems
Authors: Zhou Mo , Dai Yafei , Li Xiaoming
Published: September 2007

The architecture of P2P file-sharing applications has been developing to meet the needs of large scale demands. The structured overlay network, also known as DHT, has been used in these applications to improve the scalability, and robustness of the system, and to make it free from single-point failure. We believe that the measurement study of the overlay network used in the real file-sharing P2P systems can provide guidance for the designing of such systems, and improve the performance of the system. In this paper, we perform the measurement in two different aspects. First, a modified client is designed to provide view to the overlay network from a single-user vision. Second, the instances of crawler programs deployed in many nodes managed to crawl the user information of the overlay network as much as possible. We also find a vulnerability in the overlay network, combined with the character of the DNS service, a more serious DDoS attack can be launched.
World Wide Web Resources on Obstetrical and Gynecological Infections
Authors: Athanasiou Stavros , Pitsouni Eleni , Iavazzo Christos , Karamanis Eirinaios M. , Falagas Matthew E.
Published: September 2007

Modern information and communications technology has provided medical students and practitioners around the world with a new, valuable, and easy-to-use way to retrieve potentially useful information. Using previously described by our research group methodology, we generated a list of 50 Internet resources in the field of obstetrical and gynecological infections. We believe that the availability of such a list will help in the education of students and clinicians interested in obstetrical and gynecological infections.
The Effect of Emodin-Assisted Early Enteral Nutrition on Severe Acute Pancreatitis and Secondary Hepatic Injury
Authors: Wang Gang , Sun Bei , Gao Yue , Meng Qing Hui , Jiang Hong Chi
Published: September 2007

Severe acute pancreatitis (SAP) characterized by atrocious progression and numerous complications often leads to a high mortality rate due to hypermetabolism, systemic inflammatory response syndrome (SIRS), and multiple organs dysfunction syndrome (MODS). Studies have revealed that both early enteral nutrition (EEN) and emodin are potent agents in the management of SAP. However, whether the combined strategy is rational and more effective than either one alone remains unknown. In this regard, Wistar rats were treated with emodin-assisted EEN (EAEEN) through enteral nutrient tubes after induction of SAP by retrograde infusion of 5.0% sodium taurocholate into the common pancreatic duct. Serum levels of amylase, tumor necrosis factor-alpha (TNF-α), angiotensin II (AngII), maleic dialdehyde (MDA), glutamic pyruvic transaminase (ALT), glutamic oxaloacetic transaminase (AST) and C-reactive protein (CRP), intestinal secretory IgA (SIgA), pancreatic and hepatic myeloperoxidase (MPO) activity as well as plasma levels of D-lactate and endotoxin were measured. In addition, pathologic alterations of pancreas and liver were observed microscopically. We found that EAEEN could significantly ameliorate these parameters and prevent pancreas and liver from serious damage. In conclusion, Our results indicated that EAEEN could exert beneficial effects on experimental SAP and obviously abate the severity of secondary hepatic injury. The combined strategy was safe and more effective than either one alone in the acute stage of SAP. This study also provided an experimental base for the clinical treatment of SAP patients with EAEEN.
Reliability of Modules with Load-Sharing Components
Authors: Bebbington Mark , Lai Chin-Diew , Zitikis Ricardas
Published: September 2007

To increase the reliability of modules,
and thus of systems assembled from them, they are frequently
constructed using parallel load-sharing components. Examples include
jet engines, electrical power networks, and telecommunications
networks. We consider the situation when the components operate
independently, but when any one of them fails, the load of the
failed component is instantaneously distributed among the working
components. The entire module fails when the last working component
fails. We analyze the survival probability and residual life
expectancy of such modules. An obvious application is to the case of
the 1998 Auckland power supply failure in New Zealand.
Experimental Study on Bioluminescence Tomography with Multimodality Fusion
Authors: Lv Yujie , Tian Jie , Cong Wenxiang , Wang Ge
Published: September 2007

To verify the influence of a priori information on the nonuniqueness problem of bioluminescence tomography (BLT), the multimodality imaging fusion based BLT experiment is performed by multiview noncontact detection mode, which incorporates the anatomical information obtained by the microCT scanner and the background optical properties based on diffuse reflectance measurements. In the reconstruction procedure, the utilization of adaptive finite element methods (FEMs) and a priori permissible source region refines the reconstructed results and improves numerical robustness and efficiency. The comparison between the absence and employment of a priori information shows that multimodality imaging fusion is essential to quantitative BLT reconstruction.
Globally Decoupled Reputations for Large Distributed Networks
Authors: Swamynathan Gayatri , Zhao Ben Y. , Almeroth Kevin C. , Zheng Haitao
Published: September 2007

Reputation systems help establish social control in peer-to-peer networks. To be truly effective, however, a reputation system should counter attacks that compromise the reliability of user ratings. Existing reputation approaches either average a peer's lifetime ratings or account for rating credibility by weighing each piece of feedback by the reputation of its source. While these systems improve cooperation in a P2P network, they are extremely vulnerable to unfair ratings attacks. In this paper, we recommend that reputation systems decouple a peer'sservice providerreputation from itsservice recommenderreputation, thereby, making reputations more resistant to tampering. We propose a scalable approach to system-wide decoupled service and feedback reputations and demonstrate the effectiveness of our model against previous nondecoupled reputation approaches. Our results indicate that decoupled approache significantly improves reputation accuracy, resulting in more successful transactions. Furthermore, we demonstrate the effectiveness and scalability of our decoupled approach as compared to PeerTrust, an alternative mechanism proposed for decoupled reputations. Our results are compiled from comprehensive logs collected from Maze, a large file-sharing system with over 1.4 million users supporting searches on 226TB of data.
Inhibition of Human Immunodeficiency Virus Type 1 Activity by Purified Human Breast Milk Mucin (MUC1) in an Inhibition Assay
Authors: Habte Habtom H. , de Beer Corena , Lotz Zoë E. , Tyler Marilyn G. , Kahn Delawir , Mall Anwar S.
Published: September 2007

It has been reported that breast-feeding is responsible for approximately 40% of the HIV transmissions from HIV-positive mothers to children. Human breast milk, however, is known to contain numerous biologically active components which protect breast-fed infants against bacteria, viruses, and toxins. The purpose of this study was to purify and characterize breast milk mucin and to determine its anti-HIV-1 activity in an HIV inhibition assay. Sepharose CL-4B column chromatography and caesium chloride isopycnic density gradient purification were used to isolate and purify the mucin. Following Western blotting and amino acid analysis, an HIV-1 inhibition assay was carried out to determine the anti-HIV-1 activity of crude breast milk and purified milk mucin (MUC1) by incubating them with HIV-1 prior to infection of the human T lymphoblastoid cell line (CEM SS cells). SDS-PAGE analysis of the mucin, together with its amino acid composition and Western blotting, suggested that this purified mucin from human breast milk was MUC1. The HIV inhibition assay revealed that while the purified milk mucin (MUC1) inhibited the HIV-1 activity by approximately 97%, there was no inhibition of the HIV-1 activity by crude breast milk. Although the reason for this is not clear, it is likely that because the MUC1 in crude milk is enclosed by fat globules, there may not be any physical contact between the mucin and the virus in the crude breast milk. Thus, there is a need to free the mucin from the fat globules for it to be effective against the virus.
The Time Course and Determinants of Blood Pressure within the First 48 h after Ischemic Stroke
Authors: Wong Andrew A. , Davis James P. , Schluter Philip J. , Henderson Robert D. , O’Sullivan John D. , Read Stephen J.
Published: September 2007

Background and Purpose: Previous research suggests that blood pressure falls acutely after ischemic stroke. We aimed to further characterize this fall with a statistical technique that allows the application of regression techniques to serial blood pressure outcome data. Methods: In a prospectively recruited ischemic stroke cohort, systolic (SBP) and diastolic (DBP) blood pressure was recorded every 4 h until 48 h after stroke. Potential determinants of blood pressure, including stroke severity and acute infection, were also recorded. Mixed effects models were used to model serial blood pressure measurements over time, adjusted for significant determinants. Results: In 156 patients, SBP and DBP fell by 14.9 mm Hg (95% CI 6.2–22.6 mm Hg) and 6.2 mm Hg (95% CI 1.4–10.6 mm Hg), respectively, over the first 48 h after stroke. SBP was higher in patients with premorbid hypertension, a previous history of stroke or TIA, current alcohol use, increasing age, stroke of mild to moderate severity (NIHSS 3–13) and in patients treated with antihypertensives. SBP was lower in smokers. There was a progressive rise in SBP in patients with acute infection. No factors other than time were associated with DBP. Conclusions: The use of mixed effects models has identified a linear SBP and DBP fall over the first 48 h after stroke. The timing and magnitude of this fall should be accounted for in the design of future prognostic and intervention studies.
Does Calcium Deposition Play a Role in the Stability of Atheroma? Location May Be the Key
Authors: Li Zhi-Yong , Howarth Simon , Tang Tjun , Graves Martin , U-King-Im Jean , Gillard Jonathan H.
Published: September 2007

Background: Rupture of vulnerable atheromatous plaque in the carotid and coronary arteries often leads to stroke and heart attack respectively. The role of calcium deposition and its contribution to plaque stability is controversial. This study uses both an idealized and a patient-specific model to evaluate the effect of a calcium deposit on the stress distribution within an atheromatous plaque. Methods: Using a finite-element method, structural analysis was performed on an idealized plaque model and the location of a calcium deposit within it was varied. In addition to the idealized model, in vivo high-resolution MR imaging was performed on 3 patients with carotid atheroma and stress distributions were generated. The individual plaques were chosen as they had calcium at varying locations with respect to the lumen and the fibrous cap. Results: The predicted maximum stress was increased by 47.5% when the calcium deposit was located in the thin fibrous cap in the model when compared with that in a model without a deposit. The result of adding a calcium deposit either to the lipid core or remote from the lumen resulted in almost no increase in maximal stress. Conclusion: Calcification at the thin fibrous cap may result in high stress concentrations, ultimately increasing the risk of plaque rupture. Assessing the location of calcification may, in the future, aid in the risk stratification of patients with carotid stenosis.
Stroke Code Chest Radiographs Are Not Useful
Authors: Goldstein Larry B.
Published: September 2007

Background: Routine chest radiographs at the time of hospital admission are not recommended for stroke patients in the absence of pulmonary symptoms. The usefulness of the test in patients being evaluated by a stroke team for hyperacute stroke symptoms was assessed. Methods: Demographic information, chest radiograph results, and the impact of the test on the emergency department (ED) management of a consecutive series of patients evaluated by a stroke code team between 2005–2006 were retrospectively collected and analyzed. Results: Chest radiographs were obtained in the ED for 92% of patients (n = 113). The sole indication for the test was ‘stroke’ in 91% (one patient had a normal study performed for chest pain; the remainder were performed in association with endotracheal intubation). Chest radiographs were completely normal in 70% with 25.2% having incidental and 3.8% having potentially relevant findings. No patient had a finding that otherwise affected their ED management. Conclusion: Routine chest radiographs obtained as part of the emergent evaluation of patients with acute stroke symptoms rarely provide useful information, expose the patient to unnecessary radiation, add costs, and can interfere with other more critical parts of the patient’s emergent assessment.
Dual Action of Nitric Oxide in the Pathogenesis of Ischemia/Reperfusion-Induced Mucosal Injury in Mouse Stomach
Authors: Kobata Atsushi , Kotani Tohru , Komatsu Yoshino , Amagase Kikuko , Kato Shinichi , Takeuchi Koji
Published: September 2007

Aim: We investigated the roles of NO/NOS isoforms in the pathogenesis of ischemia/reperfusion (I/R)-induced gastric injury in mouse stomachs. Methods: Under urethane anesthesia, the celiac artery was clamped, and then reperfusion was established 30 min later by removal of the clamp. After a 60-min reperfusion, the stomach was examined for macroscopic lesions. Results: Following I/R, hemorrhagic lesions were generated in the mucosa, although ischemia alone caused no visible damage. Prior administration of L-NAME (a nonselective NOS inhibitor) significantly aggravated these lesions, in a L-arginine-inhibitable manner. By contrast, the selective iNOS inhibitor 1400W significantly prevented the occurrence of I/R-induced gastric lesions. The mucosal MPO activity was increased after I/R, and this response was enhanced and attenuated by prior administration of L-NAME and 1400W, respectively. Interestingly, the later treatment with L-NAME, given 10 min before reperfusion, significantly reduced the severity of the I/R-induced gastric damage, in a L-arginine-dependent manner. The expression of iNOS mRNA was up-regulated in the stomach following I/R, with an increase of mucosal NO content, and the NO production was significantly inhibited by both L-NAME and 1400W. Conclusion: Endogenous NO plays a dual role in the pathogenesis of IR-induced gastric damage; NO/cNOS is protective while NO/iNOS is proulcerogenic during I/R.
Extending the Platinum-Free Interval with a Non-Platinum Therapy in Platinum-Sensitive Recurrent Ovarian Cancer
Authors: Pignata Sandro , Ferrandina Gabriella , Scarfone Giovanna , Scollo Paolo , Odicino Franco , Selvaggi Luigi , Katsaros Dionyssios , Frigerio Luigi , Mereu Liliana , Ghezzi Fabio , Manzione Luigi , Lauria Rossella , Breda Enrico , Marforio Giovanna , Ballardini Michela , Vernaglia Lombardi Alessandra , Sorio Roberto , Tumolo Salvatore , Costa Bruno , Magni Giovanna , Perrone Francesco , Favalli Giuseppe
Published: September 2007

Background: It has been proposed that extending the platinum-free interval with intervening non-platinum therapy increases the efficacy of a later re-treatment with platinum in platinum-sensitive recurrent ovarian cancer. This hypothesis is based on data from small series and although it has not been validated prospectively, this strategy has entered general practice in Italy in the last years. The SOCRATES study retrospectively assessed the pattern of care of a cohort of patients with recurrent platinum-sensitive ovarian cancer observed in the years 2000–2002 in 37 Italian centres. Data were collected between April and September 2005. Methods: Patients with recurrent ovarian cancer with a platinum-free interval >6 months were eligible. 493 patient files were collected and 428 were eligible and analyzed. Results: The interval from the end of the 1st line to relapse was 6–12 months in 164 patients (39.5%) and >12 months in 251 cases (60.5%). Patients received a 2nd (100%), 3rd (80.1%), 4th (50.2%), 5th (28.3%), and 6th (11.9%) line of chemotherapy. At 2nd line 282 (65.9%) received platinum (group A), while 146 (34.1%) received non-platinum chemotherapy (group B). In the latter group, 67 patients received platinum at later progression (group B1), while 79 never received platinum (group B2). Median time to platinum re-treatment was 20 and 23.1 months in patients of groups A and B1, respectively. The response rate to the first platinum received was 74.4 and 57.4% in groups A and B1, respectively (p = 0.02). Group B2 was characterized by the worst response rate and survival. At multivariate analysis time of first platinum re-treatment (2nd line vs. later; p = 0.0132; OR = 2.34) and age (p = 0.0029; OR = 2.41) was independently associated with a higher possibility of response to platinum. Conclusions: With the limits of a retrospective study, our data question the hypothesis that extending the platinum-free interval with an intervening non-platinum therapy in patients with recurrent platinum-sensitive ovarian cancer improves the response rate of a further platinum re-treatment.
Assessing Statistical Applications in Publications on Alzheimer’s Disease
Authors: Xiong Chengjie , Tang Yuxiao , van Belle Gerald , Miller J. Philip , Launer Lenore J. , Bergmann Kelly R. , Morris John C.
Published: September 2007

Background/Aims: To evaluate statistical applications in publications on Alzheimer’s disease (AD). Methods: Three instruments/checklists were developed: Assessment of Statistical Reporting (ASR; 44 items), Survey of Statistical Designs (SSD; 10 items), and Survey of Statistical Methods (SSM; 7 items). After a pilot testing on 5 AD publications, the instruments/checklists were revised and tested for reliability with a sample of 30 AD articles and for validity with another sample of 10 AD articles from MEDLINE. Results: Item-specific test-retest and interrater reliability for ASR ranged from 0.29 to 1.0 with the associated standard errors (SEs) ranging from 0.01 to 0.31. The test-retest reliability (intraclass correlation coefficient = 0.94, 95% CI: 0.88–0.97) and the interrater reliability (intraclass correlation coefficient = 0.84, 95% CI: 0.69–0.92) for the overall score of ASR were high. The correlational validity of the ASR with a published checklist was also high (r = 0.74, SE = 0.24). The item-specific test-retest reliability in SSD and SSM ranged from 0.58 to 1.00 with the associated SEs ranging from 0.01 to 0.32. The item-specific interrater reliability in SSD and SSM ranged from 0.17 to 1.00 with the associated SEs ranging from 0.01 to 0.22. Conclusions: This study suggested that it was feasible to assess statistical applications in AD publications.
Case-Finding for MS Prevalence Studies in Small Communities Requires a Community-Based Approach
Authors: Cowen Joel B. , Sjostrom Barbara F. , Doughty Andrea S. , Schiffer Randolph B.
Published: September 2007

In response to citizen concerns in 5 small Illinois towns, community-based case-finding determined the prevalence of multiple sclerosis (MS). Potential cases were identified through town meetings, publicity, advocacy groups and local volunteer outreach coordinators. Estimated prevalence based on available medical records for self-identifying individuals for 3 of the 5 communities was high (218–231 per 100,000 population) compared to other studies. Scanning databases in medical offices used in many other studies may miss MS cases; yet tracking medical records is labor-intensive and sometimes restricted by privacy guidelines. MS registries could improve case-finding accuracy and efficiency.
Cognitive Performance and Neural Correlates of Detecting Driving Hazards in Healthy Older Adults
Authors: Hirth Victor A. , Davis Ben , Fridriksson Julius , Rorden Chris , Bonilha Leonardo
Published: September 2007

Background/Aims: In spite of the growing number of seniors who drive and their relatively frequent involvement in accidents, little is known about the cognitive substrates of road hazard recognition and their relationship with general cognitive performance in this population. We aimed to investigate, using a combination of functional MRI (fMRI) and a comprehensive neuropsychological battery, the anatomical and cognitive components of driving hazard recognition. Methods: Fourteen healthy active drivers aged between 65 and 87 years underwent neuropsychological evaluation and fMRI scanning. fMRI was performed while subjects watched a video composed of clips of driving hazards randomly interspersed with uneventful driving clips. We investigated brain areas that are recruited for hazard detection, in contrast to brain areas responding to driving without a hazard. The performance on neuropsychological tests was then regressed with the degree of activation of cortical areas related exclusively to detecting hazards. Results: Driving hazards generated significant activations, compared to non-hazards, in the lateral associative occipital cortex and in the right prefrontal cortex. Intensity of brain activation was correlated on performance on memory and cognitive control neuropsychological tests. Conclusion: Future studies can possibly address the same relationship in early dementia, as a preliminary form of investigation for driving safety.
Correlation between Facial Pattern Recognition and Brain Composition in Paper Wasps
Authors: Gronenberg Wulfia , Ash Lesley E. , Tibbetts Elizabeth A.
Published: September 2007

Unique among insects, some paper wasp species recognize conspecific facial patterns during social communication. To evaluate whether specialized brain structures are involved in this task, we measured brain and brain component size in four different paper wasp species, two of which show facial pattern recognition. These behavioral abilities were not reflected by an increase in brain size or an increase in the size of the primary visual centers (medulla, lobula). Instead, wasps showing face recognition abilities had smaller olfactory centers (antennal lobes). Although no single brain compartment explains the wasps’ specialized visual abilities, multi-factorial analysis of the different brain components, particularly the antennal lobe and the mushroom body sub-compartments, clearly separates those species that show facial pattern recognition from those that do not. Thus, there appears to be some neural specialization for visual communication in Polistes. However, the apparent lack of optic lobe specialization suggests that the visual processing capabilities of paper wasps might be preadapted for pattern discrimination and the ability to discriminate facial markings could require relatively small changes in their neuronal substrate.
Early Diencephalon Development in Alligator
Authors: Pritz Michael B.
Published: September 2007

Diencephalon development was investigated in a reptilian embryo, Alligator mississipiensis, beginning at a single compartment stage and continuing until internal subdivisions were present within major units. A variety of morphological techniques were used: immunocytochemistry, histochemistry, and cresyl violet staining. The diencephalon begins as a single unit. In the transverse domain, the diencephalon subsequently divides into two: the parencephalon and the synencephalon. The parencephalon then splits into the parencephalon anterior and parencephalon posterior. Still later, the synencephalon undergoes parcellation into the synencephalon anterior and synencephalon posterior. Subsequently, internal subdivisions occur in each of these four compartments. When the diencephalon has become subdivided into two compartments and continuing until internal subdivisions are present in each unit, a longitudinal border separating a dorsal, presumed alar plate, from a ventral, presumed basal plate, was seen. No clear cut subunits were reliably identified in the telencephalon or secondary prosencephalon during this period of early development in Alligator. Early diencephalon development in birds (chick) and mammals (humans) follows a similar pattern. Specifically, a single diencephalic compartment divides into two zones: the par-encephalon and synencephalon. Subsequently, the parencephalon becomes subdivided into an anterior and posterior unit. Some studies, including the present one, have noted further parcellation of the synencephalon into an anterior and posterior component, whereas others have not. Notwithstanding differences as to whether the synencephalon is a single unit or not, these detailed analyses in reptiles (Alligator), birds (chick), and mammals (humans), suggest that the initial pattern of early diencephalon development in amniotes is similar.
Significance of Immunohistochemical Expression of p27 and Involucrin as the Marker of Cellular Differentiation of Squamous Cell Carcinoma of the Esophagus
Authors: Nozoe Tadahiro , Oyama Tsunehiro , Takenoyama Mistuhiro , Hanagiri Takeshi , Sugio Kenji , Yasumoto Kosei
Published: September 2007

Purpose: p27kip1 belongs to the KIP/CIP family of cyclin-dependent kinase inhibitors and is considered to be a tumor suppressor. Involucrin has been known as a marker of differentiation of squamous cell carcinoma (SCC). The aim of this study was to evaluate the clinicopathologic significance of the expression of p27 and involucrin in esophageal SCC. Methods: Immunohistochemical expression of p27 and involucrin was examined in 70 specimens of esophageal SCC. The correlation of the expression of these proteins and clinicopathologic features was evaluated. Results: Cellular differentiation in esophageal SCC was significantly correlated with the expression of p27 and involucrin (p = 0.010 and p = 0.002, respectively). Among well, moderately and poorly differentiated SCCs, 45.8 ± 21.6, 20.0 ± 15.0 and 10.6 ± 9.1% of carcinoma cells expressed involucrin, respectively (p < 0.0001 for well vs. poorly, p < 0.0001 for well vs. moderately, and p = 0.042 for moderately vs. poorly). There existed a more powerful statistical difference regarding the histological grade between SCCs with the expression of both p27 and involucrin and tumors with other expression patterns (p = 0.0001). Conclusions: Expression of both p27 and involucrin can be a powerful biological marker of cellular differentiation of esophageal SCC.
Development of a Fast and Reliable Method for the Assessment of Microbial Colonization and Growth on Textiles by DNA Quantification
Authors: Teufel Linda , Schuster K.Christian , Merschak Petra , Bechtold Thomas , Redl Bernhard
Published: September 2007

There is a lack of relevant methods to assess the colonization of textiles by skin bacteria because present methods are mainly culture-based procedures. Therefore, the goal of this study was to develop a fast and sensitive culture-independent procedure for the quantification of microbial colonization and growth on textiles. We have established a suitable protocol to use DNA quantification as a reliable method for in vitroand in vivoinvestigations of textiles. For DNA extraction, a two-step procedure comprising treatment of the textile with a solution containing Triton X-100 and lysozyme for 1 h and a successive treatment by SDS and proteinase K for 2 h turned out to be most efficient. DNA extracted from textiles and fabrics was than quantified with the highly sensitive PicoGreen fluorescent dye. In vitrochallenge tests demonstrated a strong correlation between numbers of bacteria on textiles and amount of DNA extracted from textiles. Therefore, this method was used to compare different materials after in vivotrials for assessment of their susceptibility for microbial colonization and growth.
Empirical Master Equations. Part I: Numerical Properties
Authors: Dall’Amico Mauro , Egger Joseph
Published: September 2007

In the atmospheric sciences, master equations are mainly used in a discrete time approximation to provide forecasts of the probability density function in a discretized phase space spanned by a few climate variables. The coefficients of an empirical master equation (EME) are estimated from the relative frequencies of transitions observed in time series of the variables. The quality of an EME depends on, among other things, the length and time resolution of the available time series. In this part of the paper, these dependencies are studied on the basis of data from the three-component Lorenz model with additional white noise forcing. Thus, time series of almost any length and time resolution can be generated easily, and probability density forecasts can be compared directly with the evolution of an ensemble of points. Useful results are obtained by partitioning the phase space into several hundred cells of equal grid size. The authors find that a threshold length of the time series exists beyond which improvements in the performance of the EME are hard to detect. It is even more surprising that the performance deteriorates with reduction of the time step. This is due to an increase in numerical diffusion. The choice of the dimensionality and the selection of the variables of the EME are very important. The results of this part of the paper provide useful guidelines for any application of the EME in the atmospheric sciences and elsewhere. The second part of the paper illustrates the usefulness of these guidelines through applications to stratospheric dynamics.
Eddy–Zonal Flow Feedback in the Southern Hemisphere Winter and Summer
Authors: Yang Xiaosong , Chang Edmund K. M.
Published: September 2007

The eddy–zonal flow feedback in the Southern Hemisphere (SH) winter and summer is investigated in this study. The persistence time scale of the leading principal components (PCs) of the zonal-mean zonal flow shows substantial seasonal variation. In the SH summer, the persistence time scale of PC1 is significantly longer than that of PC2, while the persistence time scales of the two PCs are quite similar in the SH winter. A storm-track modeling approach is applied to demonstrate that seasonal variations of eddy–zonal flow feedback for PC1 and PC2 account for the seasonal variations of the persistence time scale. The eddy feedback time scale estimated from a storm-track model simulation and a wave-response model diagnostic shows that PC1 in June–August (JJA) and December–February (DJF), and PC2 in JJA, have significant positive eddy–mean flow feedback, while PC2 in DJF has no positive feedback. The consistency between the persistence and eddy feedback time scales for each PC suggests that the positive feedback increases the persistence of the corresponding PC, with stronger (weaker) positive feedback giving rise to a longer (shorter) persistence time scale.

Eliassen–Palm flux diagnostics have been performed to demonstrate the dynamics governing the positive feedback between eddies and anomalous zonal flow. The mechanism of the positive feedback, for PC1 in JJA and DJF and PC2 in JJA, is as follows: an enhanced baroclinic wave source (heat fluxes) at a low level in the region of positive wind anomalies propagates upward and then equatorward from the wave source, thus giving momentum fluxes that reinforce the wind anomalies. The difference of PC2 between DJF and JJA is because of the zonal asymmetry of the climatological flow in JJA. For PC2 in DJF, wind anomalies reinforce the climatological jet, thus increasing the barotropic shear of the jet flow. The “barotropic governor” plays an important role in suppressing eddy generations for PC2 in DJF and thus inhibiting the positive eddy–zonal flow feedback.
Asymmetrization Mechanism of Jet Profiles in Decaying β-Plane Turbulence
Authors: Ishioka Keiichi , Hasegawa Jitsuko , Yoden Shigeo
Published: September 2007

In a previous paper, asymmetry was found in jet profiles between eastward and westward jets, which appear spontaneously in two-dimensional β-plane decaying turbulence. That is, westward jets are narrower and more intense than eastward jets. In this paper, the dependence of the asymmetry on the order of hyperviscosity is examined. It is shown that the dependence is not as strong as expected in the previous paper. A revised theoretical scenario to explain the weak dependence is also given.
On the Arrest of Inverse Energy Cascade and the Rhines Scale
Authors: Sukoriansky Semion , Dikovskaya Nadejda , Galperin Boris
Published: September 2007

The notion of the cascade arrest in a β-plane turbulence in the context of continuously forced flows is revised in this paper using both theoretical analysis and numerical simulations. It is demonstrated that the upscale energy propagation cannot be stopped by a β effect and can only be absorbed by friction. A fundamental dimensional parameter in flows with a β effect, the Rhines scale, LR, has traditionally been associated with the cascade arrest or with the scale that separates turbulence and Rossby wave–dominated spectral ranges. It is shown that rather than being a measure of the inverse cascade arrest, LR is a characteristic of different processes in different flow regimes. In unsteady flows, LR can be identified with the moving energy front propagating toward the decreasing wavenumbers. When large-scale energy sink is present, β-plane turbulence may attain several steady-state regimes. Two of these regimes are highlighted: friction-dominated and zonostrophic. In the former, LR does not have any particular significance, while in the latter, the Rhines scale nearly coincides with the characteristic length associated with the large-scale friction. Spectral analysis in the frequency domain demonstrates that Rossby waves coexist with turbulence on scales smaller than LR thus indicating that the Rhines scale cannot be viewed as a crossover between turbulence and Rossby wave ranges.
Prediction and Diagnosis of Tropical Cyclone Formation in an NWP System. Part III: Diagnosis of Developing and Nondeveloping Storms
Authors: Tory K. J. , Davidson N. E. , Montgomery M. T.
Published: September 2007

This is the third of a three-part investigation into tropical cyclone (TC) genesis in the Australian Bureau of Meteorology’s Tropical Cyclone Limited Area Prediction System (TC-LAPS), an operational numerical weather prediction (NWP) forecast model. In Parts I and II, a primary and two secondary vortex enhancement mechanisms were illustrated, and shown to be responsible for TC genesis in a simulation of TC Chris. In this paper, five more TC-LAPS simulations are investigated: three developing and two nondeveloping. In each developing simulation the pathway to genesis was essentially the same as that reported in Part II. Potential vorticity (PV) cores developed through low- to middle-tropospheric vortex enhancement in model-resolved updraft cores (primary mechanism) and interacted to form larger cores through diabatic upscale vortex cascade (secondary mechanism). On the system scale, vortex intensification resulted from the large-scale mass redistribution forced by the upward mass flux, driven by diabatic heating, in the updraft cores (secondary mechanism). The nondeveloping cases illustrated that genesis can be hampered by (i) vertical wind shear, which may tilt and tear apart the PV cores as they develop, and (ii) an insufficient large-scale cyclonic environment, which may fail to sufficiently confine the warming and enhanced cyclonic winds, associated with the atmospheric adjustment to the convective updrafts.

The exact detail of the vortex interactions was found to be unimportant for qualitative genesis forecast success. Instead the critical ingredients were found to be sufficient net deep convection in a sufficiently cyclonic environment in which vertical shear was less than some destructive limit. The often-observed TC genesis pattern of convection convergence, where the active convective regions converge into a 100-km-diameter center, prior to an intense convective burst and development to tropical storm intensity is evident in the developing TC-LAPS simulations. The simulations presented in this study and numerous other simulations not yet reported on have shown good qualitative forecast success. Assuming such success continues in a more rigorous study (currently under way) it could be argued that TC genesis is largely predictable provided the large-scale environment (vorticity, vertical shear, and convective forcing) is sufficiently resolved and initialized.
Modulation of Westerly Wind Bursts by Sea Surface Temperature: A Semistochastic Feedback for ENSO
Authors: Gebbie Geoffrey , Eisenman Ian , Wittenberg Andrew , Tziperman Eli
Published: September 2007

Westerly wind bursts (WWBs) in the equatorial Pacific are known to play a significant role in the development of El Niño events. They have typically been treated as a purely stochastic external forcing of ENSO. Recent observations, however, show that WWB characteristics depend upon the large-scale SST field. The consequences of such a WWB modulation by SST are examined using an ocean general circulation model coupled to a statistical atmosphere model (i.e., a hybrid coupled model). An explicit WWB component is added to the model with guidance from a 23-yr observational record. The WWB parameterization scheme is constructed such that the likelihood of WWB occurrence increases as the western Pacific warm pool extends: a “semistochastic” formulation, which has both deterministic and stochastic elements. The location of the WWBs is parameterized to migrate with the edge of the warm pool. It is found that modulation of WWBs by SST strongly affects the characteristics of ENSO. In particular, coupled feedbacks between SST and WWBs may be sufficient to transfer the system from a damped regime to one with self-sustained oscillations. Modulated WWBs also play a role in the irregular timing of warm episodes and the asymmetry in the size of warm and cold events in this ENSO model. Parameterizing the modulation of WWBs by an increase of the linear air–sea coupling coefficient seems to miss important dynamical processes, and a purely stochastic representation of WWBs elicits only a weak ocean response. Based upon this evidence, it is proposed that WWBs may need to be treated as an internal part of the coupled ENSO system, and that the detailed knowledge of wind burst dynamics may be necessary to explain the characteristics of ENSO.
Limitations of the Wegener–Bergeron–Findeisen Mechanism in the Evolution of Mixed-Phase Clouds
Authors: Korolev Alexei
Published: September 2007

Phase transformation and precipitation formation in mixed-phase clouds are usually associated with the Wegener–Bergeron–Findeisen (WBF) process in which ice crystals grow at the expense of liquid droplets. The evolution of mixed-phase clouds, however, is closely related to local thermodynamical conditions, and the WBF process is just one of three possible scenarios. The other two scenarios involve simultaneous growth or evaporation of liquid droplets and ice particles. Particle evolution in the other two scenarios differs significantly from that associated with the WBF process. Thus, during simultaneous growth, liquid droplets compete for the water vapor with the ice particle, which slows down the depositional growth of ice particles instead of promoting their growth at the expense of the liquid as in the WBF process. It is shown that the WBF process is expected to occur under a limited range of conditions and that ice particles and liquid droplets in mixed-phase clouds are not always processed in accordance with the WBF mechanism.
Family Matters
Authors: Hadani Michael
Published: September 2007

This study explores the impact of publicly traded founding family firms (FFFs) on their propensity for corporate political activity (CPA) and their choice of political approaches. Based on the behavior and characteristics of publicly traded FFFs, the author expected a positive association between FFFs and corporate political activity and a preference for relational, or long-term, over transactional, or short-term, corporate political activity. It was found that publicly traded FFFs are more likely to engage in CPA only when the firm's founder is in an executive position. Furthermore, publicly traded FFFs show a preference for relational versus transactional corporate political activity. These findings are examined in light of FFF and corporate political strategy literatures.
The Political Capital of Foreign Subsidiaries
Authors: Blumentritt Tim , Rehbein Kathleen
Published: September 2007

This article explores the concept of political capital in the setting of multinational corporation foreign subsidiaries. Drawing on resource dependence theory, the literature on corporate political activities, and the bargaining power framework, hypotheses are developed examining the antecedents to subsidiary political capital. The article tests hypotheses based on primary data from 91 foreign subsidiaries using path analysis. The empirical results suggest that both ownership of bargaining power resources and the management of those resources through government affairs activities are important in explaining the variation of political capital across foreign subsidiaries.