bluuebunny/crossref_metadata_2025 huggingface dataset:
Operative delivery rates following induction of labour for obstetric cholestasis
Authors: Webster Jessica R , Chappell Lucy , Cheng Floria , Breeze Andrew C G , Lucas Nuala , Plaat Felicity , Williamson Catherine
Published: May 2011

The aim of this study was to determine whether women induced for obstetric cholestasis (OC) have increased rates of operative delivery compared with women without OC who are induced. This retrospective case-control study included 64 women with OC (singleton pregnancies), who had labour induced compared with two control groups (matched for parity and gestational week at delivery). The majority of women were induced at 37 weeks. We found no significant increase in the rate of operative or assisted delivery in OC cases compared with either control group. Women with OC who are induced between 36 and 40 weeks gestation do not have increased rates of assisted or operative delivery compared with induced controls.
The rocks and shallows of deep RNA sequencing: Examples in the Vibrio cholerae RNome
Authors: Raabe Carsten A. , Hoe Chee Hock , Randau Gerrit , Brosius Juergen , Tang Thean Hock , Rozhdestvensky Timofey S.
Published: May 2011

New deep RNA sequencing methodologies in transcriptome analyses identified a wealth of novel nonprotein-coding RNAs (npcRNAs). Recently, deep sequencing was used to delineate the small npcRNA transcriptome of the human pathogen Vibrio cholerae and 627 novel npcRNA candidates were identified. Here, we report the detection of 223 npcRNA candidates in V. cholerae by different cDNA library construction and conventional sequencing methods. Remarkably, only 39 of the candidates were common to both surveys. We therefore examined possible biasing influences in the transcriptome analyses. Key steps, including tailing and adapter ligations for generating cDNA, contribute qualitatively and quantitatively to the discrepancies between data sets. In addition, the state of 5′-end phosphorylation influences the efficiency of adapter ligation and C-tailing at the 3′-end of the RNA. Finally, our data indicate that the inclusion of sample-specific molecular identifier sequences during ligation steps also leads to biases in cDNA representation. In summary, even deep sequencing is unlikely to identify all RNA species, and caution should be used for meta-analyses among alternatively generated data sets.
Hippocampal Neuronal Nitric Oxide Synthase Mediates the Stress-Related Depressive Behaviors of Glucocorticoids by Downregulating Glucocorticoid Receptor
Authors: Zhou Qi-Gang , Zhu Li-Juan , Chen Chen , Wu Hai-Yin , Luo Chun-Xia , Chang Lei , Zhu Dong-Ya
Published: May 2011

The molecular mechanisms underlying the behavioral effects of glucocorticoids are poorly understood. We report here that hippocampal neuronal nitric oxide synthase (nNOS) is a crucial mediator. Chronic mild stress and glucocorticoids exposures caused hippocampal nNOS overexpression via activating mineralocorticoid receptor. In turn, hippocampal nNOS-derived nitric oxide (NO) significantly downregulated local glucocorticoid receptor expression through both soluble guanylate cyclase (sGC)/cGMP and peroxynitrite (ONOO−)/extracellular signal-regulated kinase signal pathways, and therefore elevated hypothalamic corticotrophin-releasing factor, a peptide that governs the hypothalamic-pituitary-adrenal axis. More importantly, nNOS deletion or intrahippocampal nNOS inhibition and NO-cGMP signaling blockade (using NO scavenger or sGC inhibitor) prevented the corticosterone-induced behavioral modifications, suggesting that hippocampal nNOS is necessary for the role of glucocorticoids in mediating depressive behaviors. In addition, directly delivering ONOO−donor into hippocampus caused depressive-like behaviors. Our findings reveal a role of hippocampal nNOS in regulating the behavioral effects of glucocorticoids.
Spinal Vascular Endothelial Growth Factor Induces Phrenic Motor Facilitation via Extracellular Signal-Regulated Kinase and Akt Signaling
Authors: Dale-Nagle Erica A. , Satriotomo Irawan , Mitchell Gordon S.
Published: May 2011

Although vascular endothelial growth factor (VEGFA-165) is primarily known for its role in angiogenesis, it also plays important neurotrophic and neuroprotective roles for spinal motor neurons. VEGFA-165 signals by activating its receptor tyrosine kinase VEGF receptor-2 (VEGFR-2). Because another growth/trophic factor that signals via a receptor tyrosine kinase (brain derived neurotrophic factor) elicits a long-lasting facilitation of respiratory motor activity in the phrenic nerve, we tested the hypothesis that VEGFA-165 elicits similar phrenic motor facilitation (pMF). Using immunohistochemistry and retrograde labeling techniques, we demonstrate that VEGFA-165 and VEGFR-2 are expressed in identified phrenic motor neurons. Furthermore, intrathecal VEGFA-165 administration at C4 elicits long-lasting pMF; intraspinal VEGFA-165 increased integrated phrenic nerve burst amplitude for at least 90 min after injection (53.1 ± 5.0% at 90 min;p< 0.001). Intrathecal VEGFA-165 increased phosphorylation (and presumed activation) of signaling molecules downstream from VEGFR-2 within the phrenic motor nucleus, including ERK (1.53 ± 0.13 vs 1.0 ± 0.05 arbitrary units in control rats;p< 0.05) and Akt (2.16 ± 0.41 vs 1.0 ± 0.41 arbitrary units in control rats;p< 0.05). VEGF-induced pMF was attenuated by the MEK/ERK inhibitor U0126 [1,4-diamino-2,3-dicyano-1,4-bis(o-aminophenylmercapto)butadiene] and was abolished by the phosphotidinositol 3 kinase/Akt inhibitor LY294002 [2-(4-morpholinyl)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride], demonstrating that ERK mitogen-activated protein kinases and Akt are both required for full expression of VEGF-induced pMF. This is the first report that VEGFA-165 elicits plasticity in any motor system. Furthermore, because VEGFA-165 expression is hypoxia sensitive, it may play a role in respiratory plasticity after prolonged exposures to low oxygen.
Spectral and Temporal Sensitivity of Cone-Mediated Responses in Mouse Retinal Ganglion Cells
Authors: Wang Yanbin V. , Weick Michael , Demb Jonathan B.
Published: May 2011

The retina uses two photoreceptor types to encode the wide range of light intensities in the natural environment. Rods mediate vision in dim light, whereas cones mediate vision in bright light. Mouse photoreceptors include only 3% cones, and the majority of these coexpress two opsins (short- and middle-wavelength sensitive, S and M), with peak sensitivity to either ultraviolet (360 nm) or green light (508 nm). The M/S-opsin ratio varies across the retina but has not been characterized functionally, preventing quantitative study of cone-mediated vision. Furthermore, physiological and behavioral measurements suggested that mouse retina supports relatively slow temporal processing (peak sensitivity, ∼2–5 Hz) compared to primates; however, past studies used visible wavelengths that are inefficient at stimulating mouse S-opsin. Here, we measured the M/S-opsin expression ratio across the mouse retina, as reflected by ganglion cell responsesin vitro, and probed cone-mediated ganglion cell temporal properties using ultraviolet light stimulation and linear systems analysis. From recordings in mice lacking rod function (Gnat1−/−,Rho−/−), we estimate ∼70% M-opsin expression in far dorsal retina, dropping to <5% M-opsin expression throughout ventral retina. In mice lacking cone function (Gnat2cpfl3), light-adapted rod-mediated responses peaked at ∼5–7 Hz. In wild-type mice, cone-mediated responses peaked at ∼10 Hz, with substantial responsiveness up to ∼30 Hz. Therefore, despite the small percentage of cones, cone-mediated responses in mouse ganglion cells are fast and robust, similar to those in primates. These measurements enable quantitative analysis of cone-mediated responses at all levels of the visual system.
Inter-regional Contribution of Enhanced Activity of the Primary Somatosensory Cortex to the Anterior Cingulate Cortex Accelerates Chronic Pain Behavior
Authors: Eto Kei , Wake Hiroaki , Watanabe Miho , Ishibashi Hitoshi , Noda Mami , Yanagawa Yuchio , Nabekura Junichi
Published: May 2011

Multiple cortical areas are involved in pain processing, including the primary somatosensory cortex (S1) and the anterior cingulate cortex (ACC). Although accumulations of evidence suggest that the S1 activity increases under chronic pain conditions, whether plastic change occurs or not within the S1, and whether and how the plastic change contributes to chronic pain behavior, is unknown. Here, we provide the first evidence that intra-regional remodeling within the mouse S1 accelerates chronic pain behavior by modulating neuronal activity in the ACC, one of the important cortical areas for chronic pain. Using two-photon Ca2+imaging, we found that the spontaneous activity of layer 2/3 neurons in the S1 and then response to sensory and layer 4 stimulations increased under chronic pain conditions. In addition, pharmacological attenuation and facilitation of S1 activity attenuated and facilitated the chronic pain behavior, respectively. Furthermore, electrical response of the ACC to peripheral stimulation successfully correlated with S1 neuronal activity, and inhibition of ACC activity alleviated the mechanical allodynia. The present results will provide development of efficient therapeutic strategies against chronic pain by focusing on the S1 and ACC.
Anatomical and Functional Assemblies of Brain BOLD Oscillations
Authors: Baria Alexis T. , Baliki Marwan N. , Parrish Todd , Apkarian A. Vania
Published: May 2011

Brain oscillatory activity has long been thought to have spatial properties, the details of which are unresolved. Here we examine spatial organizational rules for the human brain oscillatory activity as measured by blood oxygen level-dependent (BOLD) signal. Resting-state BOLD signal was transformed into frequency space (Welch's method) and averaged across subjects, and its spatial distribution was studied as a function of four frequency bands, spanning the full BOLD bandwidth. The brain showed anatomically constrained distribution of power for each frequency band. This result was replicated on a repository dataset of 195 subjects. Next, we examined larger-scale organization by parceling the neocortex into regions approximating Brodmann areas (BAs). This indicated that BAs of simple function/connectivity (unimodal), versus complex properties (transmodal), are dominated by low-frequency BOLD oscillations, and within the visual ventral stream we observe a graded shift of power to higher-frequency bands for BAs further removed from the primary visual cortex (increased complexity), linking BOLD frequency properties to hodology. Additionally, BOLD oscillation properties for the default mode network demonstrated that it is composed of distinct frequency-dependent regions. When the same analysis was performed on a visual–motor task, frequency-dependent global and voxelwise shifts in BOLD oscillations could be detected at brain sites mostly outside those identified with general linear modeling. Thus, analysis of BOLD oscillations in full bandwidth uncovers novel brain organizational rules, linking anatomical structures and functional networks to characteristic BOLD oscillations. The approach also identifies changes in brain intrinsic properties in relation to responses to external inputs.
The Timing for Neuronal Maturation in the Adult Hippocampus Is Modulated by Local Network Activity
Authors: Piatti Verónica C. , Davies-Sala M. Georgina , Espósito M. Soledad , Mongiat Lucas A. , Trinchero Mariela F. , Schinder Alejandro F.
Published: May 2011

The adult hippocampus continuously generates new cohorts of immature neurons with increased excitability and plasticity. The window for the expression of those unique properties in each cohort is determined by the time required to acquire a mature neuronal phenotype. Here, we show that local network activity regulates the rate of maturation of adult-born neurons along the septotemporal axis of the hippocampus. Confocal microscopy and patch-clamp recordings were combined to assess marker expression, morphological development, and functional properties in retrovirally labeled neurons over time. The septal dentate gyrus displayed higher levels of basal network activity and faster rates of newborn neuron maturation than the temporal region. Voluntary exercise enhanced network activity only in the temporal region and, in turn, accelerated neuronal development. Finally, neurons developing within a highly active environment exhibited a delayed maturation when their intrinsic electrical activity was reduced by the cell-autonomous overexpression of Kir2.1, an inward-rectifying potassium channel. Our findings reveal a novel type of activity-dependent plasticity acting on the timing of neuronal maturation and functional integration of newly generated neurons along the longitudinal axis of the adult hippocampus.
Tactile–Auditory Shape Learning Engages the Lateral Occipital Complex
Authors: Kim Jung-Kyong , Zatorre Robert J.
Published: May 2011

Shape is an object property that inherently exists in vision and touch, and is processed in part by the lateral occipital complex (LOC). Recent studies have shown that shape can be artificially coded by sound using sensory substitution algorithms and learned with behavioral training. This finding offers a unique opportunity to test intermodal generalizability of the LOC beyond the sensory modalities in which shape is naturally perceived. Therefore, we investigated the role of the LOC in processing of shape by examining neural activity associated with learning tactile-shape-coded auditory information. Nine blindfolded sighted people learned the tactile–auditory relationship between raised abstract shapes and their corresponding shape-coded sounds over 5 d of training. Using functional magnetic resonance imaging, subjects were scanned before and after training during a task in which they first listened to a shape-coded sound transformation, then touched an embossed shape, and responded whether or not the tactile stimulus matched the auditory stimulus in terms of shape. We found that behavioral scores improved after training and that the LOC was commonly activated during the auditory and tactile conditions both before and after training. However, no significant training-related change was observed in magnitude or size of LOC activity; rather, the auditory cortex and LOC showed strengthened functional connectivity after training. These findings suggest that the LOC is available to different sensory systems for shape processing and that auditory–tactile sensory substitution training leads to neural changes allowing more direct or efficient access to this site by the auditory system.
Temporal Trade-Off Effects in Sustained Attention: Dynamics in Visual Cortex Predict the Target Detection Performance during Distraction
Authors: Wieser Matthias J. , Keil Andreas
Published: May 2011

Models of visual selective attention have suggested that the representation of specific features characterizing a target object is enhanced in the visual cortex, at the cost of competing task-irrelevant information. In psychophysical studies, however, such attentional enhancement has been shown to result in reduced perceptual sensitivity when maintained over periods of several seconds. Two experiments examined the relationship between target detection behavior and electrocortical facilitation in human visual cortex during sustained attention under competition, in near real time. Steady-state visual evoked potentials (ssVEPs) were used in a change detection paradigm, in which a stream of flickering grating stimuli containing target events was fully overlapping with distractor faces (experiment 1) or competing complex scenes (experiment 2), covering the same part of the visual field. Beamformer source localization was used to test plausibility of lower-tier visual cortex involvement in modulation of the ssVEP signal. Results of both experiments suggest that early overallocation of visual cortical resources to the attended stimulus stream is associated with rapid reduction of electrocortical facilitation and poor change detection across the entire trial. By contrast, temporally balanced dynamics in visual cortex predicted accurate change detection. Together, the present results support models of sustained selective attention that emphasize competition for resources in lower-tier visual cortex. These models can be extended by a temporal dimension, on which attentive behavior is characterized by frugal resource sharing across the viewing time.
Sustained Neuronal Activity Generated by Glial Plasticity
Authors: Pirttimaki Tiina M. , Hall Stephen D. , Parri H. Rheinallt
Published: May 2011

Astrocytes release gliotransmitters, notably glutamate, that can affect neuronal and synaptic activity. In particular, astrocytic glutamate release results in the generation of NMDA receptor (NMDA-R)-mediated slow inward currents (SICs) in neurons. However, factors underlying the emergence of SICs and their physiological roles are essentially unknown. Here we show that, in acute slices of rat somatosensory thalamus, stimulation of lemniscal or cortical afferents results in a sustained increase of SICs in thalamocortical (TC) neurons that outlasts the duration of the stimulus by 1 h. This long-term enhancement of astrocytic glutamate release is induced by group I metabotropic glutamate receptors and is dependent on astrocytic intracellular calcium. Neuronal SICs are mediated by extrasynaptic NR2B subunit-containing NMDA-Rs and are capable of eliciting bursts. These are distinct from T-type Ca2+channel-dependent bursts of action potentials and are synchronized in neighboring TC neurons. These findings describe a previously unrecognized form of excitatory, nonsynaptic plasticity in the CNS that feeds forward to generate local neuronal firing long after stimulus termination.
Cell Death Triggers Olfactory Circuit Plasticity via Glial Signaling inDrosophila
Authors: Kazama Hokto , Yaksi Emre , Wilson Rachel I.
Published: May 2011

TheDrosophilaantennal lobe is organized into glomerular compartments, where olfactory receptor neurons synapse onto projection neurons. Projection neuron dendrites also receive input from local neurons, which interconnect glomeruli. In this study, we investigated how activity in this circuit changes over time when sensory afferents are chronically removedin vivo. In the normal circuit, excitatory connections between glomeruli are weak. However, after we chronically severed receptor neuron axons projecting to a subset of glomeruli, we found that odor-evoked lateral excitatory input to deafferented projection neurons was potentiated severalfold. This was caused, at least in part, by strengthened electrical coupling from excitatory local neurons onto projection neurons, as well as increased activity in excitatory local neurons. Merely silencing receptor neurons was not sufficient to elicit these changes, implying that severing receptor neuron axons is the relevant signal. When we expressed the neuroprotective gene Wallerian degeneration slow (WldS) in receptor neurons before severing their axons, this blocked the induction of plasticity. Because expressing WldSprevents severed axons from recruiting glia, this result suggests a role for glia. Consistent with this, we found that blocking endocytosis in ensheathing glia blocked the induction of plasticity. In sum, these results reveal a novel injury response whereby severed sensory axons recruit glia, which in turn signal to central neurons to upregulate their activity. By strengthening excitatory interactions between neurons in a deafferented brain region, this mechanism might help boost activity to compensate for lost sensory input.
Intraneuronal APP, Not Free Aβ Peptides in 3xTg-AD Mice: Implications for Tau versus Aβ-Mediated Alzheimer Neurodegeneration
Authors: Winton Matthew J. , Lee Edward B. , Sun Eveline , Wong Margaret M. , Leight Susan , Zhang Bin , Trojanowski John Q. , Lee Virginia M.-Y.
Published: May 2011

Alzheimer's disease (AD) is characterized by the accumulation of intraneuronal tau and extracellular amyloid-β (Aβ) peptide. A triple transgenic (Tg) mouse (3xTg-AD) was reported to develop Aβ plaques and tau inclusions as well as remarkable accumulations of intracellular Aβ that were suggested to be the initiators of AD pathogenesis. However, it was unclear whether the anti-Aβ antibodies were able to distinguish Aβ peptide from the same Aβ epitopes within the amyloid precursor protein (APP). To further elucidate the identity of the immunoreactive intraneuronal material in 3xTg-AD mice, we conducted immunohistochemical, biochemical, and ultrastructural studies using a well characterized panel of antibodies that distinguish Aβ within APP from cleaved Aβ peptides. We found that the intraneuronal material shared epitopes with full-length APP but not free Aβ. To demonstrate unequivocally that this intraneuronal material was not free Aβ peptide, we generated 3xTg-AD mice deficient for β-secretase (BACE), the protease required for Aβ generation from APP. In the absence of Aβ production, robust intraneuronal APP immunostaining was detected in the 3xTg-AD/BACE−/−mice. Finally, we found that the formation of tau lesions was not different between 3xTg-AD versus 3xTg-AD/BACE−/−mice, thereby demonstrating that tau pathology forms independently from Aβ peptide generation in this mouse model. Although we cannot corroborate the presence of intraneuronal Aβ peptide in 3xTg-AD mice, our findings warrant further study as to the role of aberrant APP accumulation in this unique model of AD.
Gene expression in mouse ovarian follicle development in vivo versus an ex vivo alginate culture system
Authors: Parrish Elizabeth M , Siletz Anaar , Xu Min , Woodruff Teresa K , Shea Lonnie D
Published: May 2011

Ovarian follicle maturation results from a complex interplay of endocrine, paracrine, and direct cell–cell interactions. This study compared the dynamic expression of key developmental genes during folliculogenesisin vivoand duringin vitroculture in a 3D alginate hydrogel system. Candidate gene expression profiles were measured within mouse two-layered secondary follicles, multi-layered secondary follicles, and cumulus–oocyte complexes (COCs). The expression of 20 genes involved in endocrine communication, growth signaling, and oocyte development was investigated by real-time PCR. Gene product levels were compared between i) follicles of similar stage and ii) COCs derived eitherin vivoor byin vitroculture. For follicles cultured for 4 days, the expression pattern and the expression level of 12 genes were the samein vivoandin vitro. Some endocrine (cytochrome P450, family 19, subfamily A, polypeptide 1 (Cyp19a1) and inhibin βA subunit (Inhba)) and growth-related genes (bone morphogenetic protein 15 (Bmp15), kit ligand (Kitl), and transforming growth factor β receptor 2 (Tgfbr2)) were downregulated relative toin vivofollicles. For COCs obtained from cultured follicles, endocrine-related genes (inhibin α-subunit (Inha) andInhba) had increased expression relative toin vivocounterparts, whereas growth-related genes (Bmp15, growth differentiation factor 9, and kit oncogene (Kit)) and zona pellucida genes were decreased. However, most of the oocyte-specific genes (e.g. factor in the germline α (Figla), jagged 1 (Jag1), andNlrp5(Mater)) were expressedin vitroat the same level and with the same pattern asin vivo-derived follicles. These studies establish the similarities and differences betweenin vivoandin vitrocultured follicles, guiding the creation of environments that maximize follicle development and oocyte quality.
Fly ash and limestone in diatomite-blended Portland cement
Authors: Yilmaz Bulent , Hocaoglu Eda
Published: May 2011

The aim of the present study was to investigate the use of diatomite, which has limited use in the cement industry due to its porous structure in spite of its high reactive silica content, by modifying its porous structure with fly ash and limestone blend. To this end, physical, chemical, mineralogical and zeta potential (electrokinetic) analyses were performed on raw materials. Hydration progress was followed by using standard cement tests and X-ray, and 28-day microstructures of pastes were determined by scanning electron microscopy. Raw material test results have revealed that the particle structure of the raw materials affects the grindability of composite cements, while the Si-O− content in the zeta potentials makes it negative, and the Ca2+ content makes it positive. Standard cement test results indicate that water demand and setting time of pastes were related to diatomite ratio, and fly ash and filler limestone affected the development of strength by their electrokinetic properties.
COFFERDAMS.
Authors: PACKSHAW S
Published: May 2011

The functions of cofferdams are defined, and their types are divided into two main classifications: the first constructed of soil, concrete or timber, and the second depending primarily on steel sheet piling. These are further sub-divided and listed in two charts. The choice available to the designer is discussed in relation to the permanent structure to be built within the dam, the site conditions, the depth of the cofferdam and the nature of the ground.

For design purposes cofferdamas re divided into two categories, namely singleskin and doubleskin, the latter including cellular cofferdams. The basic principles are discussed and attention is drawn to certain aspects of the design of cofferdams in both categories. Graphs for use in the preparation of preliminary designs and estimates for cofferdams of conventional construction are given.

Finally, the mechanisms of failure of cofferdams are reviewed. Reference is made to the fact that they are generally derived from the inability of the ground inside the cofferdam to withstand the external forceasn d not fromth e structural failure of the materials used in the construction.
High School Online: Pedagogy, Preferences, and Practices of Three Online Teachers
Authors: Kerr Shantia
Published: May 2011

This multiple case study explores how three online, high school teachers used technological tools to create meaningful learning activities for their students. Findings reveal that teachers use a wide variety of tools and approaches to online learning. Tools are categorized as content, communication, and management tools. Approaches include utilizing a course management system, a teacher developed and designed course, and Project Foundry, an online management tool for project-based learning. Meaningful learning was observed in all sites. However, key findings reveal that students all had few instances of peer-to-peer collaborative learning, competing issues may replace content area learning in online courses, and available tools are not fully utilized for meaningful learning.
Structuring Professional Development with an Online Community
Authors: Hodes Carol L. , Foster John C. , Pritz Sandra G. , Kelley Patricia
Published: May 2011

As part of a multiyear research study on the preparation of educators to use assessment data for instructional improvement, the present study is a pilot test of a research-based professional development intervention for career-technical teachers. Forty-eight educators at nine sites in five states participated in a 1-day workshop followed by several months of mentoring either on site, by teleconference, or website. To extend the professional learning of the workshop, educators were mentored for several months as they developed a plan for instructional improvement. To complement the mentoring, a project-specific website was the focus of a community of practice where the participants could exchange information and create threaded discussions about the process of data-driven instructional improvement. Educators need an orientation to the website features, reinforcement for their online interactions, and specific activities to complete in a timeframe if they are to use web-based professional learning communities to the fullest.
Endothelium-Derived Hyperpolarizing Factor in the Brain: Influence of Sex, Vessel Size and Disease State
Authors: Davis Catherine M , Siler Dominic A , Alkayed Nabil J
Published: May 2011

The endothelial layer of cells lining the intimal surface of blood vessels is essential for vascular function. The endothelium releases multiple vasodilator and protective factors, including nitric oxide, prostacyclin and endothelium-derived hyperpolarizing factor; an imbalance in these factors predisposes individuals to vascular diseases such as stroke. These factors are differentially regulated by vessel size, sex hormones and disease state, therefore playing differential roles in different tissues following vascular injury. In particular, the endothelium-derived hyperpolarizing factor candidate termed epoxyeicosatrienoic acid, plays a prominent role in microvessel function, especially after ischemia, thereby making this signaling pathway an attractive target for therapy in vascular disease, including stroke.
Hormone Therapy Administration in Postmenopausal Women and Risk of Stroke
Authors: Renoux Christel , Suissa Samy
Published: May 2011

HRT, consisting of estrogens alone, or in combination with a progestogen, is widely used for the relief of symptoms in postmenopausal women. Early observational studies have suggested that HRT might be associated with a reduced risk of cardio- and cerebro-vascular events. These encouraging results prompted randomized controlled trials assessing the risks and benefits of HRT in primary and secondary prevention of arterial vascular events. However, these clinical trials and further observational studies did not confirm the protective effect of HRT; it is now established that HRT increases the risk of stroke. This increased risk is mainly related to an increased risk of ischemic stroke. Oral estrogen alone and combined with progestogen are associated with a similar increased risk, which may be dose dependent. Conversely, a low dose of transdermal estrogens with or without a progestogen does not seem to be associated with such an increased risk of stroke, whereas the impact of tibolone, a synthetic steroid, remains uncertain. In summary, there is now a large amount of evidence demonstrating that HRT is associated with increased risk of stroke, in particular, ischemic subtype.
Thrombolysis Treatment for Acute Stroke: Issues of Efficacy and Utilization in Women
Authors: Reeves Mathew J , Wilkins Thomas , Lisabeth Lynda D , Schwamm Lee H
Published: May 2011

Background: Some studies report that women with ischemic stroke are more likely to benefit from intravenous tissue thrombolysis (IV tPA) treatment, but are less likely to receive the treatment compared with men. We review the literature on sex differences in utilization and efficacy of IV tPA and suggest directions for future studies. Methods: We identified studies that reported on sex differences in either the utilization or efficacy of IV tPA treatment for acute ischemic stroke. Results: Data from observational studies of IV tPA use show evidence of under-utilization in women, although wide variability between studies suggests that differences are specific to local conditions and populations. Prior analyses of randomized trial data show strong evidence that women but not men receive statistically and clinically significant benefit from IV tPA treatment. Observational studies of the effectiveness of IV tPA treatment in men and women have limited validity because of the absence of comparable control groups. Conclusion: There is good evidence that there are clinically important sex differences in both the efficacy and utilization of IV tPA, with women gaining more benefit from treatment than men. The current paradox between greater efficacy but lower utilization of IV tPA in women requires greater attention from the stroke community. Larger placebo-controlled thrombolysis trials, specifically powered to look at sex differences in treatment efficacy, and more studies designed to understand the underlying reasons for the lower utilization of IV tPA in women are required.
Effect of three different motivational techniques on oral hygiene and gingival health of patients undergoing multibracketed orthodontics
Authors: Acharya Shivesh , Goyal Ashima , Utreja Ashok Kumar , Mohanty Utkal
Published: May 2011

Objective:

To compare the effectiveness of three different motivational techniques for maintaining good oral hygiene during fixed appliance orthodontic treatment.

Materials and Methods:

A total of 62 adolescents in the age range of 12–18 years, requiring fixed orthodontic treatment were evaluated for the efficacy of three different motivational techniques, ie, conventional plaque control measures (group I), chair side motivational tests with conventional plaque control measures (group II), and phase contrast microscopy with conventional plaque control measures (group III), in improving oral hygiene and gingival health over a period of 6 months.

Results:

A gradual decline in mean plaque scores in group III was found, ie, from 1.13 ± 0.42 at baseline to 0.64 ± 0.39 at 6 months (P < .05). An intragroup analysis of mean gingivitis scores in group III showed statistically significant decline in the mean gingival scores from 1.49 ± 0.45 to 1.08 ± 0.61 over a period of 6 months(P < .05).

Conclusions:

Phase contrast microscopy along with the conventional method of plaque disclosure and demonstration of the horizontal scrubbing method of brushing have a long-lasting effect on the patient. This reduces the need of frequent reinforcement sessions of plaque control programs when compared to chair side motivational tests and conventional plaque control measures.
Long-Term Outcome of Individuals Treated With Oral Insulin
Authors: Vehik Kendra , Cuthbertson David , Ruhlig Holly , Schatz Desmond A. , Peakman Mark , Krischer Jeffrey P. ,   for the DPT-1 and TrialNet Study Groups
Published: May 2011

OBJECTIVE

To evaluate the long-term intervention effects of oral insulin on the development of type 1 diabetes and to assess the rate of progression to type 1 diabetes before and after oral insulin treatment was stopped in the Diabetes Prevention Trial–Type 1 (DPT-1).

RESEARCH DESIGN AND METHODS

The follow-up included subjects who participated in the early intervention of oral insulin (1994–2003) to prevent or delay type 1 diabetes. A telephone survey was conducted in 2009 to determine whether diabetes had been diagnosed and, if not, an oral glucose tolerance test (OGTT), hemoglobin A1c (HbA1c), and autoantibody levels were obtained on all subjects who agreed to participate.

RESULTS

Of 372 subjects randomized, 97 developed type 1 diabetes before follow-up; 75% of the remaining 275 subjects were contacted. In the interim, 77 subjects had been diagnosed with type 1 diabetes and 54 of the remainder have had an OGTT; 10 of these were diagnosed with type 1 diabetes, subsequently. Among individuals meeting the original criteria for insulin autoantibodies (IAAs) (≥80 nU/mL), the overall benefit of oral insulin remained significant (P = 0.05). However, the hazard rate in this group increased (from 6.4% [95% CI 4.5–9.1] to 10.0% [7.1–14.1]) after cessation of therapy, which approximated the rate of individuals treated with placebo (10.2% [7.1–14.6]).

CONCLUSIONS

Overall, the oral insulin treatment effect in individuals with confirmed IAA ≥80 nU/mL appeared to be maintained with additional follow-up; however, once therapy stopped, the rate of developing diabetes in the oral insulin group increased to a rate similar to that in the placebo group.
Magnetomotive cooling and excitation of carbon nanotube oscillations under voltage bias
Authors: Nordenfelt Anders
Published: May 2011

We explore a semi-classical scheme for cooling and excitation of mechanical oscillations of a suspended carbon nanotube which is incorporated as a deflection-sensitive resistor in an LRC-circuit. The active feedback consists of a magnetically induced Lorentz force. We show that, for feasible experimental parameters, we can obtain self-sustained oscillations or cooling by several orders of magnitude.
Diameter of the ductus arteriosus as a predictor of patent ductus arteriosus (PDA)
Authors: Nowak Dariusz , Kozłowska Hanna , Żurada Anna , Gielecki Jerzy
Published: May 2011

Patent ductus arteriosus (PDA) is the most prevalent cardiovascular defect and is more often seen in females; premature babies are at increased risk. For both sexes, a relationship exists between the risk of this defect occurring and the higher dimensions of the ductus arteriosus. In this study, we examined the relationship between the dimensions of the ductus arteriosus (diameter, length, capacity) and sex. We analyzed a total of 223 fetuses, 108 males and 115 females, ranging in age from four to eight months of intrauterinal life. All fetuses of normal karyotype were obtained from spontaneous abortions. None of the analyzed specimens demonstrated any visible malformations. The increase in the length and diameters of the ductus is linearly related to gestational age. The volumetric growth of this vessel was dependent on fetal age, according to the exponential function. The large number of analyzed specimens allows reliable determination of the ductus arteriosus dimensions in consecutive months of fetal life. The data obtained could be of prognostic value during echocardiographic follow-up in the fetus. We found that the dimensions analyzed did not differ with regard to sex. It is a contradiction that, more frequently PDA in females is caused with the gender differences in the dimensions of ductus arteriosus.
Environmentally benign one-pot synthesis and antimicrobial activity of 1-methyl-2,6-diarylpiperidin-4-ones
Authors: Nithya Pattusamy , Nawaz Khan Fazlur-Rahman , Roopan Selvaraj , Shankar Uma , Jin Jong
Published: May 2011

An efficient and environmentally benign one-pot method for the synthesis of 1-methyl-2,6-diarylpiperidin-4-ones using montmorillonite K-10 as a catalyst has been developed. Antimicrobial activity of the compounds has been tested against selected representatives of Gram-positive and Gram-negative bacteria and fungi.
An attempt to estimate firing temperature using OSL pre-dose sensitization of quartz
Authors: Koul Dileep , Chougaonkar Mohan
Published: May 2011

The estimation of firing temperature of ceramics using methods based on pre-dose sensitization of the 110°C TL peak of quartz have yielded incoherent results. Recently the fast component of the CW-OSL of quartz has been observed to have pre-dose characteristics similar to that of the 110°C TL peak. The motivation for this study has been to look into the feasibility of this signal, the OSL counter part of pre-dosed TL emission, for the firing temperature identification. The variation in the sensitization ratio of the TL and OSL emissions with different heating temperatures was also utilized to unveil the firing temperature mark of the specimen.
The E1’ center in natural quartz: Its formation and applications to dating and provenance researches
Authors: Toyoda Shin
Published: May 2011

Quartz is one of the minerals useful for electron spin resonance (ESR) dating. The E1′ center is one of well-known paramagnetic defects in crystalline quartz. This center has a unique feature; its intensity increases on heating. An electronic process to explain this increase was found to be controlled not only by the number of oxygen vacancies, which are the precursors, but also by the number of Al hole centers, which depend on the previous radiation dose and on the Al concentration.

The maximum intensity on heating is called the heat treated E1′ center, which has been posited to correspond to the number of oxygen vacancies in quartz and was found to be correlated with the ages of the host granites (Toyoda and Hattori, 2000). The experimental results on spin-spin relaxation times of the E1′ center indicate that external beta and gamma rays create oxygen vacancies in natural quartz rather than alpha or alpha recoil particles (Toyoda et al., 2005).

The correlation between the numbers of the oxygen vacancies in quartz and the ages of the host granite made it possible to distinguish the quartz of a sedimentary reservoir from another with different age of crystallization (Toyoda and Naruse, 2002). Quartz fractions extracted from leoss and atmospheric deposition in Japan and from sediments in Japan sea were analyzed by ESR. The temporal change of the contributions from two dust sources in China were discussed in the context of climate change.
Power and Collaboration-Consensus/Conflict in Curriculum Leadership
Authors: Ylimaki Rose M. , Brunner C. Cryss
Published: May 2011

This exploratory article draws on multiple theoretical lenses and empirical research to focus on collaboration-consensus/conflict and power as experienced within literacy curriculum change efforts. Conflict and collaboration processes are discussed in the literature but remain dualistic and lack the nuance of deeper understanding. The article presents findings from two case studies of curriculum directors and others engaged in struggles to improve literacy curricula. Findings point toward the importance of more nuanced and theoretically robust conceptions of power and collaboration-consensus/conflict in curriculum change efforts. Implications for future research, practice, and curriculum leadership preparation conclude the piece.
Covariate Measurement Error Adjustment for Multilevel Models With Application to Educational Data
Authors: Battauz Michela , Bellio Ruggero , Gori Enrico
Published: May 2011

This article proposes a multilevel model for the assessment of school effectiveness where the intake achievement is a predictor and the response variable is the achievement in the subsequent periods. The achievement is a latent variable that can be estimated on the basis of an item response theory model and hence subject to measurement error. Ignoring covariate measurement error leads to biased parameter estimates. To address this problem, a likelihood-based measurement error adjustment for multilevel models is proposed. In particular, the method deals with a covariate measured with error that has a random coefficient. An application to educational data from the Italian region of Lombardy illustrates the method.

Manuscript received January 21, 2009 Revision received November 24, 2009 Accepted January 17, 2010
Diversity, distribution and host range of mistletoe in protected and unprotected areas of Central Nepal Himalayas
Authors: Devkota MP , Joshi GP , Parajuli P
Published: May 2011

Diversity, distribution and host range of mistletoe were assessed in protected and unprotected areas of the Central Nepal Himalayas. This study recorded ten mistletoe species. Occurrence of all ten mistletoe species within the Shivpuri Nagarjun National Park (SNNP) was a clear indication that national parks provide better habitat for mistletoe species richness and thus a better opportunity for biodiversity conservation than in unprotected areas. For these mistletoes, a total of 34 host species of 21 unrelated families were documented. Scurrula genus of the Loranthaceae family had the highest number of species, the highest number of host species, and the widest altitudinal distribution. Variation in climatic factors, edge effect, disperser behaviour, fragmented forests and the availability of suitable host species determine the occurrence of a particular mistletoe species in a particular habitat. Key words: Diversity: distribution: host range: mistletoe: Nepal DOI: 10.3126/banko.v20i2.4797 Banko Janakari Vol.20(2) 2010 pp.14-20
Targeting the Mammalian Target of Rapamycin (mTOR) in Cancer Therapy: Lessons from Past and Future Perspectives
Authors: Dufour Marc , Dormond-Meuwly Anne , Demartines Nicolas , Dormond Olivier
Published: May 2011

Over the last decade, extensive studies have been made to understand the role played by the mammalian target of rapamycin (mTOR) in cancer. Knowledge in this field has been gained from discoveries in basic research as well as from observations made in patients treated with allosteric mTOR inhibitors such as rapamycin. Despite promising preclinical studies, targeting mTOR in cancer therapy has shown limited clinical benefits so far. However, recent findings have revealed the complexity of the functions of mTOR in cancer and have helped develop new strategies to improve the anticancer efficacy of mTOR inhibitors. In particular, a complex network between mTOR and other signaling pathways has been identified that influences the anticancer efficacy of mTOR inhibitors. In addition, an emerging role of mTOR in the tumor microenvironment has been suggested. In this review, we confront the major findings that have been made in the past, both in experimental settings as well as in clinical trials. We further review the strategies that have been designed to further improve the efficacy of therapies targeting mTOR.
Activation of PDGFr-β Signaling Pathway after Imatinib and Radioimmunotherapy Treatment in Experimental Pancreatic Cancer
Authors: Abe Michio , Kortylewicz Zbigniew P. , Enke Charles A. , Mack Elizabeth , Baranowska-Kortylewicz Janina
Published: May 2011

Pancreatic cancer does not respond to a single-agent imatinib therapy. Consequently, multimodality treatments are contemplated. Published data indicate that in colorectal cancer, imatinib and radioimmunotherapy synergize to delay tumor growth. In pancreatic cancer, the tumor response is additive. This disparity of outcomes merited further studies because interactions between these modalities depend on the imatinib-induced reduction of the tumor interstitial fluid pressure. The examination of human and murine PDGFr-β/PDGF-B pathways in SW1990 pancreatic cancer xenografts revealed that the human branch is practically dormant in untreated tumors but the insult on the stromal component produces massive responses of human cancer cells. Inhibition of the stromal PDGFr-β with imatinib activates human PDGFr-β/PDGF-B signaling loop, silent in untreated xenografts, via an apparent paracrine rescue pathway. Responses are treatment- and time-dependent. Soon after treatment, levels of human PDGFr-β, compared to untreated tumors, are 3.4×, 12.4×, and 5.7× higher in imatinib-, radioimmunotherapy + imatinib-, and radioimmunotherapy-treated tumors, respectively. A continuous 14-day irradiation of imatinib-treated xenografts reduces levels of PDGFr-β and phosphorylated PDGFr-β by 5.3× and 4×, compared to earlier times. Human PDGF-B is upregulated suggesting that the survival signaling via the autocrine pathway is also triggered after stromal injury. These findings indicate that therapies targeting pancreatic cancer stromal components may have unintended mitogenic effects and that these effects can be reversed when imatinib is used in conjunction with radioimmunotherapy.
Temporal and Spatial Pore Water Pressure Distribution Surrounding a Vertical Landfill Leachate Recirculation Well
Authors: Kadambala Ravi , Townsend Timothy G. , Jain Pradeep , Singh Karamjit
Published: May 2011

Addition of liquids into landfilled waste can result in an increase in pore water pressure, and this in turn may increase concerns with respect to geotechnical stability of the landfilled waste mass. While the impact of vertical well leachate recirculation on landfill pore water pressures has been mathematically modeled, measurements of these systems in operating landfills have not been reported. Pressure readings from vibrating wire piezometers placed in the waste surrounding a liquids addition well at a full-scale operating landfill in Florida were recorded over a 2-year period. Prior to the addition of liquids, measured pore pressures were found to increase with landfill depth, an indication of gas pressure increase and decreasing waste permeability with depth. When liquid addition commenced, piezometers located closer to either the leachate injection well or the landfill surface responded more rapidly to leachate addition relative to those far from the well and those at deeper locations. After liquid addition stopped, measured pore pressures did not immediately drop, but slowly decreased with time. Despite the large pressures present at the bottom of the liquid addition well, much smaller pressures were measured in the surrounding waste. The spatial variation of the pressures recorded in this study suggests that waste permeability is anisotropic and decreases with depth.