bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of Raloxifene or Tamoxifen Use on Endometrial Cancer Risk: A Population-Based Case-Control Study
Authors: DeMichele Angela , Troxel Andrea B. , Berlin Jesse A. , Weber Anita L. , Bunin Greta R. , Turzo Elene , Schinnar Rita , Burgh Desiree , Berlin Michelle , Rubin Stephen C. , Rebbeck Timothy R. , Strom Brian L.
Published: November 2008

Purpose

Raloxifene reduces breast cancer risk in women with osteoporosis, and both tamoxifen and raloxifene prevent breast cancer in high-risk women. However, in vitro, raloxifene does not share the pro-estrogenic effects of tamoxifen on the endometrium. Randomized trials of these agents have provided limited information about endometrial cancer risk in the general population. We sought to compare endometrial cancer risks associated with raloxifene, tamoxifen, and nonusers of a selective estrogen receptor modulator (SERM) in the general population and characterize the endometrial tumors occurring in these groups.

Methods

We performed a case-control study of white and African American women age 50 to 79 years in the Philadelphia area. Patients were diagnosed with endometrial cancer between July 1999 and June 2002. Controls were identified through random-digit dialing.

Results

We analyzed 547 cases and 1,410 controls. Among cases, 3.3% had taken raloxifene; 6.2% had taken tamoxifen. Among controls, 6.6% had taken raloxifene; 2.4% had taken tamoxifen. After adjustment for other risk factors, the odds of endometrial cancer among raloxifene users was 50% that of nonusers (odds ratio [OR] = 0.50; 95% CI, 0.29 to 0.85), whereas tamoxifen users had three times the odds of developing endometrial cancer compared with raloxifene users (OR = 3.0; 95% CI, 1.3 to 6.9). Endometrial tumors in raloxifene users had a more favorable histologic profile and were predominantly International Federation of Gynecology and Obstetrics stage I and low grade.

Conclusion

Raloxifene users had significantly lower odds of endometrial cancer compared with both tamoxifen users and SERM nonusers, suggesting a role for raloxifene in endometrial cancer prevention and individualization of SERM therapy.
Racial and Ethnic Differences in Advance Care Planning Among Patients With Cancer: Impact of Terminal Illness Acknowledgment, Religiousness, and Treatment Preferences
Authors: Smith Alexander K. , McCarthy Ellen P. , Paulk Elizabeth , Balboni Tracy A. , Maciejewski Paul K. , Block Susan D. , Prigerson Holly G.
Published: November 2008

Purpose

Despite well-documented racial and ethnic differences in advance care planning (ACP), we know little about why these differences exist. This study tested proposed mediators of racial/ethnic differences in ACP.

Patients and Methods

We studied 312 non-Hispanic white, 83 non-Hispanic black, and 73 Hispanic patients with advanced cancer in the Coping with Cancer study, a federally funded multisite prospective cohort study designed to examine racial/ethnic disparities in ACP and end-of-life care. We assessed the impact of terminal illness acknowledgment, religiousness, and treatment preferences on racial/ethnic differences in ACP.

Results

Compared with white patients, black and Hispanic patients were less likely to have an ACP (white patients, 80%; black patients, 47%; Hispanic patients, 47%) and more likely to want life-prolonging care even if he or she had only a few days left to live (white patients, 14%; black patients, 45%; Hispanic patients, 34%) and to consider religion very important (white patients, 44%; black patients, 88%; Hispanic patients, 73%; all P < .001, comparison of black or Hispanic patients with white patients). Hispanic patients were less likely and black patients marginally less likely to acknowledge their terminally ill status (white patients, 39% v Hispanic patients, 11%; P < .001; white v black patients, 27%; P = .05). Racial/ethnic differences in ACP persisted after adjustment for clinical and demographic factors, terminal illness acknowledgment, religiousness, and treatment preferences (has ACP, black v white patients, adjusted relative risk, 0.64 [95% CI, 0.49 to 0.83]; Hispanic v white patients, 0.65 [95% CI, 0.47 to 0.89]).

Conclusion

Although black and Hispanic patients are less likely to consider themselves terminally ill and more likely to want intensive treatment, these factors did not explain observed disparities in ACP.
Serous Tubal Intraepithelial Carcinoma: Its Potential Role in Primary Peritoneal Serous Carcinoma and Serous Cancer Prevention
Authors: Carlson Joseph W. , Miron Alexander , Jarboe Elke A. , Parast Mana M. , Hirsch Michelle S. , Lee Yonghee , Muto Michael G. , Kindelberger David , Crum Christopher P.
Published: November 2008

Purpose

A diagnosis of primary peritoneal serous carcinoma (PPSC) requires exclusion of a source in other reproductive organs. Serous tubal intraepithelial carcinoma (STIC; stage 0) has been described in asymptomatic women with BRCA mutations and linked to a serous cancer precursor in the fimbria. This study examined the frequency of STIC in PPSC and its clinical outcome in BRCA-positive women.

Patients and Methods

Presence or absence of STIC was recorded in consecutive cases meeting the 2001 WHO criteria for PPSC, including 26 patients with nonuniform sampling of the fallopian tubes (group 1) and 19 patients with complete tubal examination (group 2; sectioning and extensively examining the fimbriated end, or SEE-FIM protocol). In selected cases, STIC or its putative precursor and the peritoneal tumor were analyzed for p53 mutations (exons 1 to 11). Outcome of STIC was ascertained by literature review.

Result

Thirteen (50%) of 26 PPSCs in group 1 involved the endosalpinx, with nine STICs (35%). Fifteen (79%) of 19 cases in group 2 contained endosalpingeal involvement, with nine STICs (47%). STIC was typically fimbrial and unifocal, with variable invasion of the tubal wall. In five of five cases, the peritoneal and tubal lesion shared an identical p53 mutation. Of 10 reported STICs in BRCA-positive women, all patients were without disease on follow-up.

Conclusion

The fimbria is the source of nearly one half of PPSCs, suggesting serous malignancy originates in the tubal mucosa but grows preferentially at a remote peritoneal site. The generally low risk of recurrence in stage 0 (STIC) disease further underscores STIC as a possible target for early serous cancer detection and prevention.
p53 is localized to a sub-nucleolar compartment after proteasomal inhibition in an energy-dependent manner
Authors: Karni-Schmidt Orit , Zupnick Andrew , Castillo Mirela , Ahmed Aqeel , Matos Tulio , Bouvet Philippe , Cordon-Cardo Carlos , Prives Carol
Published: November 2008

The tumor suppressor p53 is activated in response to many forms of cellular stress leading to cell cycle arrest, senescence or apoptosis. Appropriate sub-cellular localization is essential for modulating p53 function. We recently showed that p53 localizes to the nucleolus after proteasome inhibition with MG132 and this localization requires sequences within its carboxyl terminus. In the present study, we found that after treatment with MG132, p53 associates with a discrete sub-nucleolar component, the fibrillar center (FC), a region mainly enriched with RNA polymerase I. Moreover, we now demonstrate that this localization is an energy-dependent process as reduction of ATP levels prevents nucleolar localization. In addition, p53 sub-nucleolar accumulation is abolished when cells are subjected to various types of genotoxic stress. Furthermore, we show that monoubiquitination of p53, which causes it to localize to the cytoplasm and nucleoplasm, does not prevent the association of p53 with the nucleolus after MG132 treatment. Importantly, we demonstrate that p53 nucleolar association occurs in lung and bladder carcinomas.
MOR1, theArabidopsis thalianahomologue ofXenopusMAP215, promotes rapid growth and shrinkage, and suppresses the pausing of microtubules in vivo
Authors: Kawamura Eiko , Wasteneys Geoffrey O.
Published: November 2008

MOR1, the Arabidopsis thaliana homologue of the Xenopus microtubule-associated protein MAP215, is required for spatial organization of the acentrosomal microtubule arrays of plant cells. To determine how loss of MOR1 function affects microtubule dynamics, we compared various parameters of microtubule dynamics in the temperature-sensitive mor1-1 mutant at its permissive and restrictive temperatures, 21°C and 31°C, respectively. Dynamic events were tracked in live cells expressing either GFP-tagged β-tubulin or the plus end tracking EB1. Microtubule growth and shrinkage velocities were both dramatically reduced in mor1-1 at 31°C and the incidence and duration of pause events increased. Interestingly, the association of EB1 with microtubule plus ends was reduced in mor1-1 whereas side wall binding increased, suggesting that MOR1 influences the association of EB1 with microtubules either by modulating microtubule plus end structure or by interacting with EB1. Although mor1-1 microtubules grew and shrank more slowly than wild-type microtubules at 21°C, the incidence of pause was not altered, suggesting that pause events, which occur more frequently at 31°C, have a major detrimental role in the spatial organization of cortical microtubules. Extensive increases in microtubule dynamics in wild-type cells when shifted from 21°C to 31°C underline the importance of careful temperature control in live cell imaging.
Case study: Constraint-based improvement of an overwrapping machine
Authors: Neale G , Mullineux G , Matthews J , Medland T
Published: November 2008

The paper presents the successful application of a constraint-based modelling to improve the performance of an overwrapping packaging machine. The constraint-based modelling was employed to manipulate the geometry of the individual components and their assemblies until conditions of minimum misalignment forces were achieved. The designs arising from this approach moved the ground points away from their original positions and modified the geometry of the cam follower arms. It also allowed a single camshaft to be used, which enabled a reduction in the number of parts. A prototype of the new design was constructed, installed in the complete machine, and evaluated. All the performance requirements were met.
Effect of stir-casting on the microstructure and adhesive wear characteristics of cast Al—Si—Cu alloy
Authors: Reddy T V S , Dwivedi D K , Jain N K
Published: November 2008

This paper describes the microstructure, hardness, and wear characteristics of cast aluminium—silicon alloy produced by a stir-casting technique. A hypoeutectic (Al—7% Si—0.8% Cu) alloy was cast under different stirring speeds. The stirring of semi-solid metal (SSM) slurries was performed under continuous cooling conditions from liquidus temperature. Wear characteristics of the alloys under investigation were studied using a pin-on-flat wear system over a range of normal loads (10—40 N) at constant average sliding speed (0.2 m/s) against cast iron and stainless steel counter surfaces. Stir-casting resulted in a material with higher microhardness and lower wear rates than conventional cast alloy. Both the stir-cast and conventional cast alloy showed higher weight loss against the stainless steel compared with that against the cast iron counter surface. Optical microscopy of the conventional cast and stir-cast alloys showed that the stir-casting results in spheroidization and refinement of primary alpha aluminium and modification of eutectic silicon. The scanning electron microscopy of wear surfaces was carried out to investigate the mode of wear. Attempts were made to establish the structure property relationship.
Laser cutting of large-aspect-ratio rectangular blanks in thick sheet metal: Thermal stress analysis
Authors: Yilbas B S , Arif A F M , Abdul Aleen B J
Published: November 2008

The laser cutting of high-aspect-ratio (length to width) rectangular blanks from a thick sheet steel is carried out and the temperature and thermal stress fields in the cut sections are examined. The temperature and stress fields are computed using the finite element model and X-ray diffraction (XRD) is used to measure the residual stress levels in the corners of the cut geometry. A scanning electron microscope equipped with an energy dispersive spectroscopy unit is used to examine the morphological and metallurgical changes in the cut section. It is found that the von Mises stress remains high in the region of the cut surfaces and the predicted values of the residual stress closely agree with experimental results. The micrographs reveal that the cut sections are free from cracks.
Brittle and ductile removal modes observed during diamond turning of carbon nanotube composites
Authors: Jasinevicius R G , Andreeta M R B , Fossa J S , Hernandes A C , Duduch J G , Demont P , Puech P
Published: November 2008

Ultraprecision diamond turning was used to evaluate the surface integrity of a carbon nanotube (CNT) composite as a function of the cutting conditions and the percentage of CNT in the epoxy matrix. The effects of cutting conditions on the chip morphology and surface roughness were analysed. The results showed that an increase in the percentage of CNT may influence the mechanism of material removal and consequently improve the quality of the machined surface. When smaller quantities of CNT (0.02 and 0.07 wt %) are present in the matrix, microcracks form within the cutting grooves (perpendicular to the cutting direction). This indicates that the amount of CNT on the epoxy matrix may have a direct influence on the mechanical properties of these materials. Chips removed from the CNT composite samples were analysed by scanning electron microscopy in order to correlate the material removal mechanism and the surface generation process. The area average surface roughness Sa was influenced by the material removal mechanism ( Sa ranging from 0.28 to 1.1 μm).
Designing a developable surface with haptic force feedback
Authors: Tsai W-L , Lo C-H , Chu C-H
Published: November 2008

This paper investigates the possibility of using haptic technology to facilitate developable surface design. A novel method is proposed that transforms the design constraint, i.e. developability, of a surface into haptic information. Instead of the traditional way that relies mainly on visual feedback, the generated haptic force feedback reinforces the user's sense of a surface's developability. This allows him/her intuitively to manipulate a surface to the desired shape while maintaining the surface developability to a specified degree. To verify this idea, an experiment is carried out with a prototype system to compare the user's performances on designing developable patches with and without haptic force feedback. The result has shown that when haptic force feedback is present, the user completes the design tasks in less time and with higher accuracy. This work demonstrates a potential of using haptic technology for physical modelling of freeform geometry.
Darrieus turbines: The physics of self-starting
Authors: Hill N , Dominy R , Ingram G , Dominy J
Published: November 2008

As the demand for renewable energy grows, the use of small wind turbines becomes increasingly attractive. Turbines using vertical-axis geometries are particularly suited to the urban environment by virtue of their operation being independent of wind direction. However, such designs have received much less attention than the more common ‘propeller type’ designs and the understanding of some aspects of their operation remains weak. This is particularly true of their starting characteristics. Indeed, some authors maintain that they cannot start without external assistance.

In this investigation a numerical model is used to simulate the starting of an H-rotor Darrieus turbine under steady wind conditions. Experimental wind-tunnel data for a small prototype is presented, demonstrating unaided start-up of a three-bladed Darrieus in a steady wind. Discrepancy between the modelled and experimental results demonstrate that modelling remains constrained by the quality of data on aerofoil characteristics.
Calibration of porous medium models for brush seals
Authors: Pugachev A O , Helm P
Published: November 2008

One of the theoretical approaches to modelling brush seals is based on the porous medium models. In this approach, influence of the brush on the flow is defined by a set of resistance coefficients. Although these coefficients can be estimated, the brush seal model needs to be calibrated against the measurements. This work analyses calibration procedures with respect to extrapolation of the theoretical results on different brush seals and operating conditions. Two sealing configurations and two bristle packs are studied experimentally and theoretically. Computational fluid dynamics predictions and measurements of leakage, axial pressure, and brush clearance are presented. The efficiency of calibration procedures is also discussed.
Effect of biodiesel derived from Honge oil and its blends with diesel when directly injected at different injection pressures and injection timings in single-cylinder water-cooled compression ignition engine
Authors: Banapurmath N R , Tewari P G , Hosmath R S
Published: November 2008

This article investigates the effect of different injection timings and injection pressures on the performance and emission characteristics of a single-cylinder direct injection diesel engine when fuelled with Honge oil, its ester, and ester blends with diesel fuel. Experiments were conducted with three injection timings of 19°, 23°, and 27° before top dead centre (BTDC) at various loads and at a constant speed of 1500 r/min. Experiments were repeated with different injection opening pressures of 205, 220, 240, 260, and 280 bars. The performance and emission characteristics of Honge oil and blends of its ester (B10, B20, B40, B80, and B100) were studied. Also, apparent heat release rates, cumulative heat release rates, peak pressure, maximum rate of pressure rise, ignition delay, and combustion duration for these fuel combinations were obtained. With Honge oil and Honge oil methyl ester retarded injection timing of 19° BTDC resulted in overall better performance. For Honge oil, a high injection pressure of 260 bar gave better performance. Among the different blends tested (B20, B40, B80, and B100), the B20 blend showed favourable results. Therefore, only results with the B20 blend are provided in this work.
Surgery for obesity in older women
Authors: Miller Megan E , Kral John G
Published: November 2008

The global epidemic of obesity continues to grow, with over 1.7 billion people worldwide classified as obese (body mass index; BMI ≥ 30 kg/m2). Of special concern is the population of older women, since women are more obese than men and gain weight early during menopause. Obesity with co-morbidities is the leading threat to women's health and longevity. Specific female co-morbidities, such as reproductive failure, urinary stress incontinence and disproportionate prevalence of serious diseases such as diabetes, cardiovascular disease and cardiopulmonary failure in addition to breast cancer and gynaecologic malignancies, reduce the fitness benefits grandmothers provide to the species by ensuring reproductive success of their children and health and survival of grandchildren. In fact, female life-expectancy is decreasing in industrialized nations. Non-surgical treatment for obesity itself is ineffective; currently there is not enough evidence to recommend weight loss medications for routine use in the elderly and calorie-burning exercise is problematic. Conversely, antiobesity surgery has been shown to be both effective and safe in the older adult population in studies that predominantly enrol women. Although the risks and benefits of antiobesity surgery performed in high-volume dedicated centres must be carefully weighed for each individual patient, the strong evidence for its safety and efficacy in reducing obesity-related co-morbidities and improving quality of life, with the potential to increase healthy life-expectancy, makes antiobesity surgery a viable treatment option for older obese women.
Functionality and substrate specificity of human box H/ACA guide RNAs
Authors: Xiao Mu , Yang Chunxing , Schattner Peter , Yu Yi-Tao
Published: November 2008

A large number of box H/ACA RNAs have been identified in human cells, and have been predicted to account for nearly all pseudouridylation sites in human rRNAs. However, the function of these mammalian H/ACA RNAs in directing pseudouridylation has been verified experimentally in only two cases. In this study, we used three in vitro reconstitution systems, including yeast and mammalian systems, to test the function of seven H/ACA RNAs guiding16 pseudouridylation sites. Our results verified 12 of these sites; four predictions were incorrect. Further analyses indicated that three components, including the stability of the hairpin structure harboring the pseudouridylation pocket, the stability of guide sequence–target RNA base-pairing interaction, and the distance between the target uridine and the box H or ACA, were critical for the guide function, as changes in these components were sufficient to alter the functionality and specificity of the pseudouridylation pocket. The dynamic functional changes in response to changes in these three important components were further tested in vivo, and the results were completely consistent with the in vitro results. Finally, we compared our results with predictions made by two computer programs, as well as predictions made by human experts using visual inspection. We found that the predictions of one program (snoGPS) agreed with our experimental results with 100% sensitivity (12/12) and 75% specificity (3/4).
Repeated Interactions and Contractual Detail: Identifying the Learning Effect
Authors: Vanneste Bart S. , Puranam Phanish
Published: November 2008

Organizations interacting repeatedly on similar transactions may learn from prior experiences, allowing contracts to be specified in greater detail. In this study, we analyze the conditions under which this learning effect is most likely to manifest itself. We do this by focusing on different parts of a contract as well as differences across transacting parties. Using a survey of information technology procurement contracts from 788 Dutch small- and medium-sized enterprises, we show that the learning effect is stronger for technical than for legal detail in contracts and is stronger for firms with information technology expertise than for firms without such expertise.
Glutamatergic Neuronal Differentiation of Mouse Embryonic Stem Cells after Transient Expression of Neurogenin 1 and Treatment with BDNF and GDNF:In VitroandIn VivoStudies
Authors: Reyes Jeannie H. , O'Shea K. Sue , Wys Noel L. , Velkey J. Matthew , Prieskorn Diane M. , Wesolowski Karolina , Miller Josef M. , Altschuler Richard A.
Published: November 2008

Differentiation of the pluripotent neuroepithelium into neurons and glia is accomplished by the interaction of growth factors and cell-type restricted transcription factors. One approach to obtaining a particular neuronal phenotype is by recapitulating the expression of these factors in embryonic stem (ES) cells. Toward the eventual goal of auditory nerve replacement, the aim of the current investigation was to generate auditory nerve-like glutamatergic neurons from ES cells. Transient expression of Neurog1 promoted widespread neuronal differentiationin vitro; when supplemented with brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF), 75% of ES cell-derived neurons attained a glutamatergic phenotype after 5 din vitro. Mouse ES cells were also placed into deafened guinea pig cochleae and Neurog1 expression was induced for 48 h followed by 26 d of BDNF/GDNF infusion.In vivodifferentiation resulted in 50–75% of ES cells bearing markers of early neurons, and a majority of these cells had a glutamatergic phenotype. This is the first study to report a high percentage of ES cell differentiation into a glutamatergic phenotype and sets the stage for cell replacement of auditory nerve.
A TrkB/EphrinA Interaction Controls Retinal Axon Branching and Synaptogenesis
Authors: Marler Katharine J. M. , Becker-Barroso Elena , Martínez Albert , Llovera Marta , Wentzel Corinna , Poopalasundaram Subathra , Hindges Robert , Soriano Eduardo , Comella Joan , Drescher Uwe
Published: November 2008

Toward understanding topographically specific branching of retinal axons in their target area, we have studied the interaction between neurotrophin receptors and members of the Eph family. TrkB and its ligand BDNF are uniformly expressed in the retina and tectum, respectively, and exert a branch-promoting activity, whereas EphAs and ephrinAs are expressed in gradients in retina and tectum and can mediate a suppression of axonal branching. We have identified a novelcisinteraction between ephrinA5 and TrkB on retinal ganglion cell axons. TrkB interacts with ephrinA5 via its second cysteine-rich domain (CC2), which is necessary and sufficient for binding to ephrinA5. Their functional interaction is twofold: ephrinA5 augments BDNF-promoted retinal axon branching in the absence of its activator EphA7–Fc, whereas EphA7–Fc application abolishes branching in a local and concentration-dependent manner. The importance of TrkB in this process is shown by the fact that overexpression of an isolated TrkB–CC2 domain interfering with the ephrinA/TrkB interaction abolishes this regulatory interplay, whereas knockdown of TrkB via RNA interference diminishes the ephrinA5-evoked increase in branching. The ephrinA/Trk interaction is neurotrophin induced and specifically augments the PI-3 kinase/Akt pathway generally known to be involved in the promotion of branching. In addition, ephrinAs/TrkB modulate axon branching and also synapse formation of hippocampal neurons. Our findings uncover molecular mechanisms of how spatially restricted axon branching can be achieved by linking globally expressed branch-promoting with differentially expressed branch-suppressing activities. In addition, our data suggest that growth factors and the EphA–ephrinA system interact in a way that affects axon branching and synapse development.
Fur Seals Display a Strong Drive for Bilateral Slow-Wave Sleep While on Land
Authors: Lyamin Oleg I. , Kosenko Peter O. , Lapierre Jennifer L. , Mukhametov Lev M. , Siegel Jerome M.
Published: November 2008

Fur seals (pinnipeds of the family Otariidae) display two fundamentally different patterns of sleep: bilaterally symmetrical slow-wave sleep (BSWS) as seen in terrestrial mammals and slow-wave sleep (SWS) with a striking interhemispheric EEG asymmetry (asymmetrical SWS or ASWS) as observed in cetaceans. We examined the effect of preventing fur seals from sleeping in BSWS on their pattern of sleep. Four northern fur seals (Callorhinus ursinus) kept on land were sleep deprived (SD) of BSWS for 3 consecutive days, followed by 1 recovery day. EEG asymmetry was evaluated both visually and by EEG spectral analysis. SD significantly reduced the percentage of high-voltage BSWS (on average to 14% of baseline) and REM sleep (to 60% of baseline) whereas the percentage of low-voltage BSWS was not affected. During the SD period, all seals repeatedly tried to enter BSWS (109–411 attempts per day). SD significantly increased the amount of ASWS in each seal when scored visually (to 116–235% of baseline) and the difference in the EEG slow-wave activity (spectral power in the range of 1.2–4.0 Hz) between the two hemispheres (117–197%) as measured by the asymmetry index. High-voltage BSWS and the amount of SWS in each hemisphere were significantly elevated during the first 4 h of recovery. These data indicate that fur seals display a homeostatic response to the loss of SWS and that alternating SWS in the two hemispheres does not adequately compensate for the absence of BSWS.
A Neural Mechanism Underlying Memory Failure in Older Adults
Authors: Stevens W. Dale , Hasher Lynn , Chiew Kimberly S. , Grady Cheryl L.
Published: November 2008

Older adults have reduced memory, primarily for recall, but also for recognition (Craik and McDowd, 1987), particularly for unfamiliar faces (Bartlett et al., 1989). Behavioral studies have shown that age-related memory declines are due in part to distraction from impaired inhibition of task-irrelevant input during encoding (Healey et al., 2008). Functional magnetic resonance imaging (fMRI) has been used to uncover the sources of memory deficits associated with aging. To date, this work has focused on successful encoding, while the neural correlates of unsuccessful encoding are unknown. Here, we provide novel evidence of a neural mechanism underlying memory failures exclusively affecting older adults. Whereas both younger and older adults showed reduced activation of brain regions important for encoding (e.g., hippocampus) during unsuccessful encoding, only older adults showed increased activity in brain regions mediating distraction (e.g., auditory cortex) and in left prefrontal cortex. Further, these regions were functionally connected with medial parietal areas, previously identified as default mode regions (Raichle and Snyder, 2007), which may reflect environmental monitoring. Our results suggest that increased distraction from task-irrelevant input (auditory in this case), associated with the unfamiliar and noisy fMRI environment, may increase environmental monitoring. This in turn could hinder suppression of default mode processing, resulting in memory failures in older adults. These findings provide novel evidence of a brain mechanism underlying the behavioral evidence that impaired inhibition of extraneous input during encoding leads to memory failure in older adults and may have implications for the ubiquitous use of fMRI for investigating neurocognitive aging.
Detection of Endogenous Retinoids in the Molluscan CNS and Characterization of the Trophic and Tropic Actions of 9-cisRetinoic Acid on Isolated Neurons
Authors: Dmetrichuk Jennifer M. , Carlone Robert L. , Jones Timothy R. B. , Vesprini Nicholas D. , Spencer Gaynor E.
Published: November 2008

Retinoic acid (RA) is an active metabolite of Vitamin A that plays an important role in the growth and differentiation of many cell types. All-transRA (atRA) is the retinoic acid isomer that has been most widely studied in the nervous system, and can induce and direct neurite outgrowth from both vertebrate and invertebrate preparations. The presence and role of the 9-cis-RA isomer in the nervous system is far less well defined. Here, we used high-pressure liquid chromatography (HPLC) and mass spectrometry (MS) to show for the first time, the presence of both atRA and 9-cis-RA in the CNS of an invertebrate. We then demonstrated that 9-cis-RA was capable of exerting the same neurotrophic and chemotropic effects on cultured neurons as atRA. In this study, significantly more cells showed neurite outgrowth in 9-cis-RA versus the EtOH vehicle control, and 9-cis-RA significantly increased the number and length of neurites from identified neurons after 4 d in culture. 9-cis-RA also extended the duration of time that cells remained electrically excitable in culture. Furthermore, we showed for the first time in any species, that exogenous application of 9-cis-RA induced positive growth cone turning of cultured neurons. This study provides the first evidence for the presence of both atRA and 9-cis-RA in an invertebrate CNS and also provides the first direct evidence for a potential physiological role for 9-cis-RA in neuronal regeneration and axon pathfinding.
The Melanocortin-3 Receptor Is Required for Entrainment to Meal Intake
Authors: Sutton Gregory M. , Perez-Tilve Diego , Nogueiras Ruben , Fang Jidong , Kim Jason K. , Cone Roger D. , Gimble Jeffrey M. , Tschöp Matthias H. , Butler Andrew A.
Published: November 2008

Entrainment of anticipatory activity and wakefulness to nutrient availability is a poorly understood component of energy homeostasis. Restricted feeding (RF) paradigms with a periodicity of 24 h rapidly induce entrainment of rhythms anticipating food presentation that are independent of master clocks in the suprachiasmatic nucleus (SCN) but do require other hypothalamic structures. Here, we report that the melanocortin system, which resides in hypothalamic structures required for food entrainment, is required for expression of food entrainable rhythms. Food anticipatory activity was assessed in wild-type (WT) and melanocortin-3 receptor-deficient (Mc3r−/−) C57BL/J mice by wheel running, spontaneous locomotory movement, and measurement of wakefulness. WT mice housed in wheel cages subject to RF exhibited increased wheel activity during the 2 h preceding meal presentation, which corresponded with an increase in wakefulness around meal time and reduced wakefulness during the dark. WT mice also exhibited increasedx- andz-movements centered around food initiation. The activity-based responses to RF were significantly impaired in mice lacking Mc3r. RF also failed to increase wakefulness in the 2 h before food presentation inMc3r−/− mice. Food entrainment requires expression ofNeuronal PAS domain 2(Npas2) andPeriod2(Per2) genes, components of the transcriptional machinery maintaining a clock rhythm. Analysis of cortical gene expression revealed severe abnormalities in rhythmic expression of clock genes (Bmal1, Npas2, Per2) underad libitumand RF conditions. In summary, Mc3r are required for expression of anticipatory patterns of activity and wakefulness during periods of limited nutrient availability and for normal regulation of cortical clock function.
Ceruloplasmin Protects Injured Spinal Cord from Iron-Mediated Oxidative Damage
Authors: Rathore Khizr I. , Kerr Bradley J. , Redensek Adriana , López-Vales Rubèn , Jeong Suh Young , Ponka Prem , David Samuel
Published: November 2008

CNS injury-induced hemorrhage and tissue damage leads to excess iron, which can cause secondary degeneration. The mechanisms that handle this excess iron are not fully understood. We report that spinal cord contusion injury (SCI) in mice induces an “iron homeostatic response” that partially limits iron-catalyzed oxidative damage. We show that ceruloplasmin (Cp), a ferroxidase that oxidizes toxic ferrous iron, is important for this process. SCI in Cp-deficient mice demonstrates that Cp detoxifies and mobilizes iron and reduces secondary tissue degeneration and functional loss. Our results provide new insights into how astrocytes and macrophages handle iron after SCI. Importantly, we show that iron chelator treatment has a delayed effect in improving locomotor recovery between 3 and 6 weeks after SCI. These data reveal important aspects of the molecular control of CNS iron homeostasis after SCI and suggest that iron chelator therapy may improve functional recovery after CNS trauma and hemorrhagic stroke.
Neogenin and RGMa Control Neural Tube Closure and Neuroepithelial Morphology by Regulating Cell Polarity
Authors: Kee Nigel , Wilson Nicole , De Vries Melissa , Bradford DanaKai , Key Brian , Cooper Helen M.
Published: November 2008

In humans, neural tube closure defects occur in 1:1000 pregnancies. The design of new strategies for the prevention of such common defects would benefit from an improved understanding of the molecular events underlying neurulation. Neural fold elevation is a key morphological process that acts during neurulation to drive neural tube closure. However, to date, the molecular pathways underpinning neural fold elevation have not been elucidated. Here, we use morpholino knock-down technology to demonstrate that Repulsive Guidance Molecule (RGMa)-Neogenin interactions are essential for effective neural fold elevation duringXenopusneurulation and that loss of these molecules results in disrupted neural tube closure. We demonstrate that Neogenin and RGMa are required for establishing the morphology of deep layer cells in the neural plate throughout neurulation. We also show that loss of Neogenin severely disrupts the microtubule network within the deep layer cells suggesting that Neogenin-dependent microtubule organization within the deep cells is essential for radial intercalation with the overlying superficial cell layer, thereby driving neural fold elevation. In addition, we show that sustained Neogenin activity is also necessary for the establishment of the apicobasally polarized pseudostratified neuroepithelium of the neural tube. Therefore, our study identifies a novel signaling pathway essential for radial intercalation and epithelialization during neural fold elevation and neural tube morphogenesis.
Catalyst-free synthesis and cathodoluminescent properties of ZnO nanobranches on Si nanowire backbones
Authors: Son Kwang-Soo , Lee Dong Hyun , Choung Jae-Woong , Pyun Yong Bum , Park Won Il , Song Taeseup , Paik Ungyu
Published: November 2008

We report the catalyst-free synthesis of ZnO nanobranches on Si nanowires using metalorganic chemical vapor deposition. The formation of single-crystalline ZnO nanobranches on Si nanowire backbones has been confirmed by lattice resolved transmission electron microscopy. Depending on the growth parameters, especially the growth temperature, the morphology and size of the ZnO nanobranches evolved from nanothorn-shaped (at 350 °C) to nanoneedle-shaped structures (at 500 °C). When the growth temperature was further increased to 800 °C, thin ZnO nanowire branches grew out of the Si nanowire backbones coated with thin ZnO shells, whereas no ZnO branch was formed on bare Si nanowires due to limited nucleation. The growth behavior was further exploited to fabricate ZnO/Si nanowire networks by growing the ZnO nanowires selectively on laterally aligned Si–ZnO core-shell nanowire arrays. In addition, cathodoluminescent properties of ZnO nanobranches on Si nanowire backbones are discussed with respect to position and size.
Comments on “Hardness, elasticity, and fracture toughness of polycrystalline spinel germanium nitride and tin nitride,” by M.P. Shemkunas, W.T. Petuskey, A.V.G. Chizmeshya, K. Leinenweber, and G.H. Wolf [J. Mater. Res. 19, 1392 (2004)]: Reestablishing of elastic moduli for γ-Ge3N4
Authors: Zerr Andreas
Published: November 2008

It will be shown that in the considered paper, a mistake occurred by handling or editing of experimental data for one of two investigated materials, namely, for cubic germanium nitride having spinel structure (γ-Ge3N4). This mistake led to incorrect values of the shear modulus G0, Young’s modulus E0, and Poisson’s ratio ν0 of this compound. My effort to recover the elastic moduli of γ-Ge3N4 from the available data gave the following results: G0 = 124 GPa, E0 = 326 GPa, and ν0 = 0.32.
Reverse polarity effect from effective charge disparity during electromigration in eutectic Sn–Zn solder interconnect
Authors: Zhang X.F. , Guo J.D. , Shang J.K.
Published: November 2008

Polarity effect on the interfacial reactions from high-density electric currents was investigated in a solder interconnect with a large disparity in the effective charge between the solder constituents. A reverse polarity effect was found where the intermetallic compound layer at the cathode grew significantly thicker than that at the anode under electric loading. Such an abnormal polarity effect was shown to result from electromigrations of Sn and Zn along opposite directions as dictated by the disparity in their effective charges. As Sn migrated to the anode under electron wind force, the resulting back stress drove Zn atoms to drift to the cathode. A kinetic analysis of the Zn mass transport explained the differential growth of the intermetallic compounds at the two electrodes, in good agreement with the experimental data.
An elementary proof of MinVol(Rn) = 0 for n > 3
Authors: Mei Jiaqiang , Wang Hongyu , Xu Haifeng
Published: November 2008

In this paper, we give an elementary proof of the result that the minimal volumes of R³ and R4 are zero. The approach is to construct a sequence of explicit complete metrics on them such that the sectional curvatures are bounded in absolute value by 1 and the volumes tend to zero. As a direct consequence, we get that MinVol (Rn) = 0 for n > 3.
Lecithotrophic behaviour in zoea and megalopa larvae of the ghost shrimp Lepidophthalmus siriboia Felder and Rodrigues, 1993 (Decapoda: Callianassidae)
Authors: Abrunhosa Fernando A. , Simith Darlan J.B. , Palmeira Carlos A.M. , Arruda Danielle C.B.
Published: November 2008

Food supply is considered critical for a successful culturing of decapod larvae. However, some species may present yolk reserve sufficient to complete their larval development without external food supply (known as lecithotrophic larval development). In the present study, two experiments were carried out in order to verify whether the callianassid Lepidophthalmus siriboia have lecithotrophic behaviour or, if they need external food for their larval development: Experiment 1, larvae submitted to an initial feeding period and Experiment 2, larvae submitted to an initial starvation period. High survival rate was observed in both experiments, in which only 2 megalopae and 1 zoea III died. These results strongly suggest that larvae of L. siriboia are lecithotrophic as they have sufficiently large yolk reserve to complete their larval development, while the megalopa stage shows facultative lecithotrophy. The larval periods of each stage of the treatments were quite similar and, despite some significant differences in some larval periods, these can be related probably to larval rearing conditions, abiotic factors or, individual variability of larval health, as well as stress caused to the ovigerous females during embryogenesis.
A note on the occurrence of praniza larvae of Gnathiidae (Crustacea, Isopoda) on fishes from Northeast of Pará, Brazil
Authors: Diniz Daniel G. , Varella Jamille E.A. , Guimarães Maria Danielle F. , Santos Arthur F.L. , Fujimoto Rodrigo Y. , Monfort Karla C.F. , Pires Marcus A.B. , Martins Maurício L. , Eiras Jorge C.
Published: November 2008

The infection of the estuarine teleost fishes Mugil gaimardianus Desmarest, 1831 (Mugilidae), Arius phrygiatus Valenciennes, 1839 (Ariidae), Conodon nobilis Linnaeus, 1759 (Haemulidae), Cetengraulis edentulus Cuvier, 1829 (Engraulidae), and Anableps anableps Linnaeus, 1758 (Anablepidae) by praniza larvae of Gnathiidae (Crustacea, Isopoda) was studied in specimens fished off the Atlantic Ocean in Northeast of Pará State, near Bragança, Brazil. The highest infection prevalence value was found in Anableps anableps (42.3%) and the lowest in Conodon nobilis (9.1%). The mean intensity varied from 1 parasitein Conodon nobilis to 19.5 in Arius phrygiatus. A description of the larvae is provided. The morphology of the mouthparts is related to the blood sucking activity, and is compared with the characteristics of other gnathiidae species.
Fluoride characterization by principal component analysis in the hydrochemical facies of Serra Geral Aquifer System in Southern Brazil
Authors: Nanni Arthur , Roisenberg Ari , Fachel Jandyra M.G. , Mesquita Gilberto , Danieli Cristiano
Published: November 2008

Principal component analysis is applied to 309 groundwater chemical data information from wells in the Serra Geral Aquifer System. Correlations among seven hydrochemical parameters are statistically examined. A four-component model is suggested and explains 81% of total variance. Component 1 represents calcium-magnesium bicarbonated groundwaters with long time of residence. Component 2 represents sulfated and chlorinated calcium and sodium groundwaters; Component 3 represents sodium bicarbonated groundwaters; and Component 4 is characterized by sodium sulfated with high fluoride facies. The components' spatial distribution shows high fluoride concentration along analyzed tectonic fault system and aligned on northeast direction in other areas, suggesting other hydrogeological fault systems. High fluoride concentration increases according to groundwater pumping depth. The Principal Component Analysis reveals features of the groundwater mixture and individualizes water facies. In this scenery, it can be determined hydrogeological blocks associated with tectonic fault system here introduced.
Petrology of dioritic, tonalitic and trondhjemitic gneisses from Encantadas Complex, Santana da Boa Vista, southernmost Brazil: paleoproterozoic continental-arc magmatism
Authors: Philipp Ruy P. , Lusa Marcelo , Nardi Lauro V.S.
Published: November 2008

The Encantadas Complex is a unit composed of dioritic, tonalitic and trondhjemitic gneisses with minor hornblendite. This complex is intruded by granites of Neoproterozoic age. Major and trace element data indicate metaluminous to slightly peraluminous composition related to the medium-K calc-alkaline series. Compositional parameters are consistent with a common evolution from less differentiated magmas, probably through fractional crystallization. The orthogneisses show LaN/YbN ratios from 10 to 50, K2O/Na2O varying from 1.1 to 3.0, Y contents from 3 to 39 ppm, Yb from 0.3 to 3.7, and Lu with contents in the range 0.06 and 0.54 ppm. Such geochemical features are similar to those of Archaean tonalitic rocks and are usually described in rocks formed by partial melting of mafic rocks under high-pressure conditions leaving an eclogitic residue. The presence of diorites and hornblendites, associated to tonalitic and trondhjemitic gneisses suggests, on the other hand, that tonalitic magmas could be formed by hornblende-controlled fractionation of hydrous basaltic magmas. Tonalitic gneisses show U-PbSHRIMP zircon age of 2, 263 ± 6 Ma for igneous crystallization and 2, 045 ± 10 Ma for the metamorphism. The geochemical parameters, tectonic and geochronological features of Encantadas Complex are consistent with magmas derived from mantle metasomatized by subduction-related fluids in a continental-arc.
Associative diazotrophic bacteria in grass roots and soils from heavy metal contaminated sites
Authors: Moreira Fátima M.S. , Lange Anderson , Klauberg-Filho Osmar , Siqueira José O. , Nóbrega Rafaela S.A. , Lima Adriana S.
Published: November 2008

This work aimed to evaluate density of associative diazotrophic bacteria populations in soil and grass root samples from heavy metal contaminated sites, and to characterize isolates from these populations, both, phenotypically (Zinc, Cadmium and NaCl tolerance in vitro, and protein profiles) and genotypically (16S rDNA sequencing), as compared to type strains of known diazotrophic species. Densities were evaluated by using NFb, Fam and JNFb media, commonly used for enrichment cultures of diazotrophic bacteria. Bacterial densities found in soil and grass root samples from contaminated sites were similar to those reported for agricultural soils. Azospirillum spp. isolates from contaminated sites and type strains from non-contaminated sites varied substantially in their in vitro tolerance to Zn+2 and Cd+2, being Cd+2 more toxic than Zn+2. Among the most tolerant isolates (UFLA 1S, 1R, S181, S34 and S22), some (1R, S34 and S22) were more tolerant to heavy metals than rhizobia from tropical and temperate soils. The majority of the isolates tolerant to heavy metals were also tolerant to salt stress as indicated by their ability to grow in solid medium supplemented with 30 g L-1 NaCl. Five isolates exhibited high dissimilarity in protein profiles, and the 16S rDNA sequence analysis of two of them revealed new sequences for Azospirillum.
A redescoberta da ética do cuidado: o foco e a ênfase nas relações
Authors: Zoboli Elma Lourdes Campos Pavone
Published: November 2008

Este artigo tem por objetivo resgatar os sentidos, os aspectos históricos e as distintas estruturas explicativas da ética do cuidado, a fim de contribuir para o debate acerca do cuidar como bem interno e razão de ser da enfermagem. Também introduz o contraponto da ética de cunho feminino e da abordagem feminista da ética, explorando as possíveis motivações para o lugar periférico que tem cabido à ética do cuidado.