bluuebunny/crossref_metadata_2025 huggingface dataset:
All Preconditioning-Related G Protein-Coupled Receptors Can Be Demonstrated in the Rabbit Cardiomyocyte
Authors: Xin Wenkuan , Yang Xiulan , Rich Thomas C. , Krieg Thomas , Barrington Robert , Cohen Michael V. , Downey James M.
Published: August 2011

G protein-coupled receptors for adenosine (A1, A3, A2A, and A2B), bradykinin (B1) and opioids (δ) are all involved in the mechanism of ischemic preconditioning. Although the heart is comprised of many tissue types, it has been assumed that preconditioning’s protective signaling occurs in the cardiomyocyte. We critically tested that hypothesis by testing for the presence of each of these receptors in isolated adult rabbit ventricular myocytes that had been transfected with cyclic nucleotide-gated (CNG) ion channels. Because subsarcolemmal cyclic adenosine monophosphate (cAMP) opens the CNG channels, we could monitor cAMP levels within a single cardiomyocyte by measuring channel current with a patch pipette. The presence of a receptor would be confirmed if we could alter cAMP in the cell with a selective agonist to the receptor being studied. Superfusion with the β-adrenergic Gs-coupled receptor agonist isoproterenol (50 nmol/L) transiently increased cAMP levels and, therefore, channel current. Pretreatment with selective agonists to A1 or A3 adenosine receptors (ARs) that are Gi-coupled markedly attenuated the response to isoproterenol, indicating inhibition of adenylyl cyclase by increased Gi activity. Agonists to bradykinin or δ-opioid receptors also attenuated isoproterenol’s response. A2AAR and A2BAR are Gs-coupled. The A2AAR–selective agonist CGS21680 increased current through CNG channels but only in the presence of phosphodiesterase (PDE) inhibitors, indicating low surface receptor activity and high intracellular PDE activity. As we previously reported, BAY 60-6583, an A2BAR-selective agonist which mimics preconditioning’s protection in rabbit heart, neither increased nor decreased membrane current in transfected cardiomyocytes, suggesting the absence or a markedly limited number of A2BAR in the sarcolemma. However, reverse transcription polymerase chain reaction (RT-PCR) of purified cardiomyocytes yielded an A2BAR band, implying that rabbit cardiomyocytes do indeed express A2BAR. These data reveal that all receptors reported to be involved in ischemic preconditioning do exist on or within the cardiomyocyte.
Drug and Alcohol Use in College Students With and Without ADHD
Authors: Baker Leigh , Prevatt Frances , Proctor Briley
Published: August 2011

Objective: This study examines differences in reported levels of drug and alcohol use between college students with and without ADHD. Method: The Michigan Alcohol Screening Test (MAST) and several self-report and interview questions, developed by Barkley, were used to examine the drug and alcohol use of college students with and without ADHD. Results: Between-group differences were found on the MAST and in the endorsement of marijuana use. Subtype differences were also found on the MAST. Several factors, including medication treatment status, ethnicity, class standing, and gender were found to be differentially related to problematic drinking behaviors. Conclusions: Difficulties in self-regulation may put college students with ADHD at a higher risk of problematic drinking and the subsequent risk for alcohol-use disorders than their peers. Possible explanations for results are discussed in terms of theory, prevention efforts, and future research.
A critical reflection on the participatory action process involved in the development of a Cognitive-behavioural-based Counselling Intervention Programme for youth living with HIV/AIDS in a rural South African town
Authors: L’Etang Shlaine , Theron Linda
Published: August 2011

South Africa currently lacks HIV counselling interventions that are youth-specific and that meet the psychosocial needs of young people living with HIV/AIDS. Indigenous strategies and interventions need to be developed that cater for the psychosocial needs of South African youth living with HIV/AIDS. By using Participatory Action Research (PAR) a Cognitive-behavioural-based Counselling Intervention Programme (CBCIP) was developed for use in a rural South African town. This article discusses the participatory action process involved in the development of the CBCIP. It shows how PAR theory relates to practice by highlighting the benefits, challenges and caveats in applying PAR within a rural setting. The lessons that were learned in the development of the CBCIP may provide future researchers with useful insight and foresight in the development of HIV counselling interventions for young people living with HIV/AIDS in South Africa.
Comparing Uncertainty Visualizations for a Dynamic Decision-Making Task
Authors: Bisantz Ann M. , Cao Dapeng , Jenkins Michael , Pennathur Priyadarshini R. , Farry Michael , Roth Emilie , Potter Scott S. , Pfautz Jonathan
Published: August 2011

Supporting complex decision making requires conveying relevant information characteristics or qualifiers. The authors tested transparency and numeric annotation for displaying uncertainty about object identity. Participants performed a “missile defense” game in which they decided whether to destroy moving objects (which were either threatening missiles or nonthreatening birds and planes) before they reached a city. Participants were provided with uncertain information about the objects’ classifica-tions. Uncertainty was represented through the transparency of icons representing the objects and/or with numeric annotations. Three display methods were created. Icons represented the most likely object classification (with solid icons), the most likely object classification (with icons whose transparency represented the level of uncertainty), or the probability that the icon was a missile (with transparency). In a fourth condition, participants could choose among the representations. Icons either were or were not annotated with numeric probability labels. Task performance was highest when participants could toggle the displays, with little effect of numeric annotation. In conditions in which probabilities were available graphically or numerically, participants chose to engage objects when they were farther from the city and had a lower probability of being a missile. Results provided continued support for the use of graphical uncertainty representations, even when numeric representations are present.
Cell-intrinsic role for IFN-α–STAT1 signals in regulating murine Peyer patch plasmacytoid dendritic cells and conditioning an inflammatory response
Authors: Li Haiyan S. , Gelbard Alexander , Martinez Gustavo J. , Esashi Eiji , Zhang Huiyuan , Nguyen-Jackson Hoainam , Liu Yong-Jun , Overwijk Willem W. , Watowich Stephanie S.
Published: August 2011

Plasmacytoid dendritic cells (pDCs) reside in bone marrrow and lymphoid organs in homeostatic conditions and typically secrete abundant quantities of type I interferons (IFNs) on Toll-like receptor triggering. Recently, a pDC population was identified within Peyer patches (PPs) of the gut that is distinguished by its lack of IFN production; however, the relationship of PP pDCs to pDCs in other organs has been unclear. We report that PP pDCs are derived from common DC progenitors and accumulate in response to Fms-like tyrosine kinase 3 ligand, yet appear divergent in transcription factor profile and surface marker phenotype, including reduced E2-2 and CCR9 expression. Type I IFN signaling via STAT1 has a cell-autonomous role in accrual of PP pDCs in vivo. Moreover, IFN-α enhances pDC generation from DC progenitors by a STAT1-dependent mechanism. pDCs that have been developed in the presence of IFN-α resemble PP pDCs, produce inflammatory cytokines, stimulate Th17 cell generation, and fail to secrete IFN-α on Toll-like receptor engagement. These results indicate that IFN-α influences the development and function of pDCs by inducing emergence of an inflammatory (Th17-inducing) antigen-presenting subset, and simultaneously regulating accumulation of pDCs in the intestinal microenvironment.
Extended passaging increases the efficiency of neural differentiation from induced pluripotent stem cells
Authors: Koehler Karl R , Tropel Philippe , Theile Jonathan W , Kondo Takako , Cummins Theodore R , Viville Stéphane , Hashino Eri
Published: August 2011

Background

The use of induced pluripotent stem cells (iPSCs) for the functional replacement of damaged neurons and in vitro disease modeling is of great clinical relevance. Unfortunately, the capacity of iPSC lines to differentiate into neurons is highly variable, prompting the need for a reliable means of assessing the differentiation capacity of newly derived iPSC cell lines. Extended passaging is emerging as a method of ensuring faithful reprogramming. We adapted an established and efficient embryonic stem cell (ESC) neural induction protocol to test whether iPSCs (1) have the competence to give rise to functional neurons with similar efficiency as ESCs and (2) whether the extent of neural differentiation could be altered or enhanced by increased passaging.

Results

Our gene expression and morphological analyses revealed that neural conversion was temporally delayed in iPSC lines and some iPSC lines did not properly form embryoid bodies during the first stage of differentiation. Notably, these deficits were corrected by continual passaging in an iPSC clone. iPSCs with greater than 20 passages (late-passage iPSCs) expressed higher expression levels of pluripotency markers and formed larger embryoid bodies than iPSCs with fewer than 10 passages (early-passage iPSCs). Moreover, late-passage iPSCs started to express neural marker genes sooner than early-passage iPSCs after the initiation of neural induction. Furthermore, late-passage iPSC-derived neurons exhibited notably greater excitability and larger voltage-gated currents than early-passage iPSC-derived neurons, although these cells were morphologically indistinguishable.

Conclusions

These findings strongly suggest that the efficiency neuronal conversion depends on the complete reprogramming of iPSCs via extensive passaging.
The CpG island methylator phenotype may confer a survival benefit in patients with stage II or III colorectal carcinomas receiving fluoropyrimidine-based adjuvant chemotherapy
Authors: Min Byung-Hoon , Bae Jeong Mo , Lee Eui Jin , Yu Hong Suk , Kim Young-Ho , Chang Dong Kyung , Kim Hee Cheol , Park Cheol Keun , Lee Suk-Hee , Kim Kyoung-Mee , Kang Gyeong Hoon
Published: August 2011

Background

Colorectal carcinoma (CRC) with CpG island methylator phenotype (CIMP) is recognized as a distinct subgroup of CRC, and CIMP status affects prognosis and response to chemotherapy. Identification of CIMP status in CRC is important for proper patient management. In Eastern countries, however, the clinicopathologic and molecular characteristics and prognosis of CRCs with CIMP are still unclear.

Methods

A total of 245 patients who underwent their first surgical resection for sporadic CRC were enrolled and CIMP status of the CRCs was determined using the quantitative MethyLight assay. The clinicopathologic and molecular characteristics were reviewed and compared according to CIMP status. In addition, the three-year recurrence-free survival (RFS) of 124 patients with stage II or stage III CRC was analyzed in order to assess the effectiveness of fluoropyrimidine-based adjuvant chemotherapy with respect to CIMP status.

Results

CIMP-high CRCs were identified in 34 cases (13.9%), and were significantly associated with proximal tumor location, poorly differentiated carcinoma, mucinous histology, and high frequencies of BRAF mutation, MGMT methylation, and MSI-high compared to CIMP-low/negative carcinomas. For patients with stage II or III CIMP-low/negative CRCs, no significant difference was found in RFS between those undergoing surgery alone and those receiving surgery with fluoropyrimidine-based adjuvant chemotherapy. However, for patients with CIMP-high CRCs, patients undergoing surgery with fluoropyrimidine-based adjuvant chemotherapy (n = 17; three-year RFS: 100%) showed significantly better RFS than patients treated with surgery alone (n = 7; three-year RFS: 71.4%) (P = 0.022).

Conclusions

Our results suggest that selected patients with CIMP-high CRC may benefit from fluoropyrimidine-based adjuvant chemotherapy with longer RFS. Further large scale-studies are required to confirm our results.
Repression of human activation induced cytidine deaminase by miR-93 and miR-155
Authors: Borchert Glen M , Holton Nathaniel W , Larson Erik D
Published: August 2011

Background

Activation Induced cytidine Deaminase (AID) targets the immunoglobulin genes of activated B cells, where it converts cytidine to uracil to induce mutagenesis and recombination. While essential for immunoglobulin gene diversification, AID misregulation can result in genomic instability and oncogenic transformation. This is classically illustrated in Burkitt's lymphoma, which is characterized by AID-induced mutation and reciprocal translocation of the c-MYC oncogene with the IgH loci. Originally thought to be B cell-specific, AID now appears to be misexpressed in several epithelial cancers, raising the specter that AID may also participate in non-B cell carcinogenesis.

Methods

The mutagenic potential of AID argues for the existence of cellular regulators capable of repressing inappropriate AID expression. MicroRNAs (miRs) have this capacity, and we have examined the publically available human AID EST dataset for miR complementarities to the human AID 3'UTR. In this work, we have evaluated the capacity of two candidate miRs to repress human AID expression in MCF-7 breast carcinoma cells.

Results

We have discovered moderate miR-155 and pronounced miR-93 complementary target sites encoded within the human AID mRNA. Luciferase reporter assays indicate that both miR-93 and miR-155 can interact with the 3'UTR of AID to block expression. In addition, over-expression of either miR in MCF-7 cells reduces endogenous AID protein, but not mRNA, levels. Similarly indicative of AID translational regulation, depletion of either miR in MCF-7 cells increases AID protein levels without concurrent increases in AID mRNA.

Conclusions

Together, our findings demonstrate that miR-93 and miR-155 constitutively suppress AID translation in MCF-7 cells, suggesting widespread roles for these miRs in preventing genome cytidine deaminations, mutagenesis, and oncogenic transformation. In addition, our characterization of an obscured miR-93 target site located within the AID 3'UTR supports the recent suggestion that many miR regulations have been overlooked due to the prevalence of truncated 3'UTR annotations.
Highly sensitive hydrogen sensor based on graphite-InP or graphite-GaN Schottky barrier with electrophoretically deposited Pd nanoparticles
Authors: Zdansky Karel
Published: August 2011

Depositions on surfaces of semiconductor wafers of InP and GaN were performed from isooctane colloid solutions of palladium (Pd) nanoparticles (NPs) in AOT reverse micelles. Pd NPs in evaporated colloid and in layers deposited electrophoretically were monitored by SEM. Diodes were prepared by making Schottky contacts with colloidal graphite on semiconductor surfaces previously deposited with Pd NPs and ohmic contacts on blank surfaces. Forward and reverse current-voltage characteristics of the diodes showed high rectification ratio and high Schottky barrier heights, giving evidence of very small Fermi level pinning. A large increase of current was observed after exposing diodes to flow of gas blend hydrogen in nitrogen. Current change ratio about 700,000 with 0.1% hydrogen blend was achieved, which is more than two orders-of-magnitude improvement over the best result reported previously. Hydrogen detection limit of the diodes was estimated at 1 ppm H2/N2. The diodes, besides this extremely high sensitivity, have been temporally stable and of inexpensive production. Relatively more expensive GaN diodes have potential for functionality at high temperatures.
Computational systems biology: integration of sequence, structure, network, and dynamics
Authors: Wang Yong , Zhang Xiang-Sun , Chen Luonan
Published: August 2011

A report of the 4nd International Conference on Computational Systems Biology, 9-11 September 2010, Suzhou, China.
Acute retroviral syndrome and high baseline viral load are predictors of rapid HIV progression among untreated Argentinean seroconverters
Authors: Socías M Eugenia , Sued Omar , Laufer Natalia , Lázaro María E , Mingrone Horacio , Pryluka Daniel , Remondegui Carlos , Figueroa María I , Cesar Carina , Gun Ana , Turk Gabriela , Bouzas María B , Kavasery Ravi , Krolewiecki Alejandro , Pérez Héctor , Salomón Horacio , Cahn Pedro ,   Grupo Argentino de Seroconversión Study Group
Published: August 2011

Background

Diagnosis of primary HIV infection (PHI) has important clinical and public health implications. HAART initiation at this stage remains controversial.

Methods

Our objective was to identify predictors of disease progression among Argentinean seroconverters during the first year of infection, within a multicentre registry of PHI‐patients diagnosed between 1997 and 2008. Cox regression was used to analyze predictors of progression (LT‐CD4 < 350 cells/mm3, B, C events or death) at 12 months among untreated patients.

Results

Among 134 subjects, 74% presented with acute retroviral syndrome (ARS). Seven opportunistic infections (one death), nine B events, and 10 non‐AIDS defining serious events were observed. Among the 92 untreated patients, 24 (26%) progressed at 12 months versus three (7%) in the treated group (p = 0.01). The 12‐month progression rate among untreated patients with ARS was 34% (95% CI 22.5‐46.3) versus 13% (95% CI 1.1‐24.7) in asymptomatic patients (p = 0.04). In univariate analysis, ARS, baseline LT‐CD4 < 350 cells/mm3, and baseline and six‐month viral load (VL) > 100,000 copies/mL were associated with progression. In multivariate analysis, only ARS and baseline VL > 100,000 copies/mL remained independently associated; HR: 8.44 (95% CI 0.97‐73.42) and 9.44 (95% CI 1.38‐64.68), respectively.

Conclusions

In Argentina, PHI is associated with significant morbidity. HAART should be considered in PHI patients with ARS and high baseline VL to prevent disease progression.
Thinner than expected? Don't blame the seismic
Authors: Coggins Jerome L.
Published: August 2011

A friend of mine was invited to be among a small group of aspiring leaders who were to give a presentation to management. While the other participants each highlighted their most significant success, he chose to explain how his department had come to lose a major client. You can guess which presentation provided the most valuable information to the company leadership. Although we have more to learn from our failures than our successes, the latter get shared much more often than the former.
True-azimuth 3D SRME in the Norwegian Sea
Authors: Smith Patrick , Szydlik Bartosz , Traylen Teufelin
Published: August 2011

True-azimuth 3D SRME techniques have proved their worth in deepwater areas that have complex water-bottom topography. However, because they take account of the true geometry of the recorded data, they also outperform 2D and nominal-azimuth 3D SRME algorithms in areas of shallower water. In regions with strong water-layer multiples, such as the Norwegian Sea, the improved multiple predictions given by true-azimuth 3D SRME can result in substantially improved data quality. Standard 3D SRME techniques accurately predict the kinematics of the multiples, but not their amplitudes. This is a disadvantage in the Norwegian Sea where low-order peg-leg multiples and higher-order simple reverberations interfere at typical reservoir depths. Iterative 3D SRME techniques can, in principle, overcome these issues, and test results on real 3D seismic data sets are promising.
A Computationally Efficient Ground-Motion Selection Algorithm for Matching a Target Response Spectrum Mean and Variance
Authors: Jayaram Nirmal , Lin Ting , Baker Jack W.
Published: August 2011

Dynamic structural analysis often requires the selection of input ground motions with a target mean response spectrum. The variance of the target response spectrum is usually ignored or accounted for in an ad hoc manner, which can bias the structural response estimates. This manuscript proposes a computationally efficient and theoretically consistent algorithm to select ground motions that match the target response spectrum mean and variance. The selection algorithm probabilistically generates multiple response spectra from a target distribution, and then selects recorded ground motions whose response spectra individually match the simulated response spectra. A greedy optimization technique further improves the match between the target and the sample means and variances. The proposed algorithm is used to select ground motions for the analysis of sample structures in order to assess the impact of considering ground-motion variance on the structural response estimates. The implications for code-based design and performance-based earthquake engineering are discussed.
Nutrient Responsive Nesfatin-1 Regulates Energy Balance and Induces Glucose-Stimulated Insulin Secretion in Rats
Authors: Gonzalez R. , Perry R. L. S. , Gao X. , Gaidhu M. P. , Tsushima R. G. , Ceddia R. B. , Unniappan S.
Published: August 2011

Nesfatin-1 is a recently discovered anorexigen, and we first reported nesfatin-like immunoreactivity in the pancreatic β-cells. The aim of this study was to characterize the effects of nesfatin-1 on whole-body energy homeostasis, insulin secretion, and glycemia. The in vivo effects of continuous peripheral delivery of nesfatin-1 using osmotic minipumps on food intake and substrate partitioning were examined in ad libitum-fed male Fischer 344 rats. The effects of nesfatin-1 on glucose-stimulated insulin secretion (GSIS) were examined in isolated pancreatic islets. L6 skeletal muscle cells and isolated rat adipocytes were used to assess the effects of nesfatin-1 on basal and insulin-mediated glucose uptake as well as on major steps of insulin signaling in these cells. Nesfatin-1 reduced cumulative food intake and increased spontaneous physical activity, whole-body fat oxidation, and carnitine palmitoyltransferase I mRNA expression in brown adipose tissue but did not affect uncoupling protein 1 mRNA in the brown adipose tissue. Nesfatin-1 significantly enhanced GSIS in vivo during an oral glucose tolerance test and improved insulin sensitivity. Although insulin-stimulated glucose uptake in L6 muscle cells was inhibited by nesfatin-1 pretreatment, basal and insulin-induced glucose uptake in adipocytes from nesfatin-1-treated rats was significantly increased. In agreement with our in vivo results, nesfatin-1 enhanced GSIS from isolated pancreatic islets at both normal (5.6 mm) and high (16.7 mm), but not at low (2 mm), glucose concentrations. Furthermore, nesfatin-1/nucleobindin 2 release from rat pancreatic islets was stimulated by glucose. Collectively, our data indicate that glucose-responsive nesfatin-1 regulates insulin secretion, glucose homeostasis, and whole-body energy balance in rats.
Visual control of steering in the box jellyfishTripedalia cystophora
Authors: Petie Ronald , Garm Anders , Nilsson Dan-Eric
Published: August 2011

Box jellyfish carry an elaborate visual system consisting of 24 eyes, which they use for driving a number of behaviours. However, it is not known how visual input controls the swimming behaviour. In this study we exposed the Caribbean box jellyfish Tripedalia cystophora to simple visual stimuli and recorded changes in their swimming behaviour. Animals were tethered in a small experimental chamber, where we could control lighting conditions. The behaviour of the animals was quantified by tracking the movements of the bell, using a high-speed camera. We found that the animals respond predictably to the darkening of one quadrant of the equatorial visual world by (1) increasing pulse frequency, (2) creating an asymmetry in the structure that constricts the outflow opening of the bell, the velarium, and (3) delaying contraction at one of the four sides of the bell. This causes the animals to orient their bell in such a way that, if not tethered, they would turn and swim away from the dark area. We conclude that the visual system of T. cystophora has a predictable effect on swimming behaviour.
Auditory selectivity for acoustic features that confer species recognition in the túngara frog
Authors: Mangiamele Lisa A. , Burmeister Sabrina S.
Published: August 2011

In anurans, recognition of species-specific acoustic signals is essential to finding a mate. In many species, behavioral tests have elucidated which acoustic features contribute to species recognition, but the mechanisms by which the brain encodes these species-specific signal components are less well understood. The túngara frog produces a `whine' mating call that is characterized by a descending frequency sweep. However, much of the signal is unnecessary for recognition, as recognition behavior can be triggered by a descending two-tone step that mimics the frequency change in a portion of the whine. To identify the brain regions that contribute to species recognition in the túngara frog, we exposed females to a full-spectrum whine, a descending two-tone step that elicits recognition, the reversed two-tone step that does not elicit recognition, or no sound, and we measured expression of the neural activity-dependent gene egr-1 in the auditory brainstem and thalamus. We found that the behavioral relevance of the stimuli was the best predictor of egr-1 expression in the laminar nucleus of the torus semicircularis but not elsewhere. That is, the laminar nucleus responded more to the whine and the two-tone step that elicits recognition than to the reversed two-tone step. In contrast, in other brainstem and thalamic nuclei, whines induced egr-1 expression but tones did not. These data demonstrate that neural responses in the laminar nucleus correspond to behavioral responses of females and they suggest that the laminar nucleus may act as a feature detector for the descending frequencies characteristic of conspecific calls.
Rodent laparoscopy: Refinement for rodent drug studies and model development, and monitoring of neoplastic, inflammatory and metabolic diseases
Authors: Baran Szczepan W , Perret-Gentil Marcel I , Johnson Elizabeth J , Miedel Emily L , Kehler James
Published: August 2011

The refinement of surgical techniques represents a key opportunity to improve the welfare of laboratory rodents, while meeting legal and ethical obligations. Current methods used for monitoring intra-abdominal disease progression in rodents usually involve euthanasia at various time-points for end of study, one-time individual tissue collections. Most rodent organ tumour models are developed by the introduction of tumour cells via laparotomy or via ultrasound-guided indirect visualization. Ischaemic rodent models are often generated using laparotomies. This approach requires a high number of rodents, and in some instances introduces high degrees of morbidity and mortality, thereby increasing study variability and expense. Most importantly, most laparotomies do not promote the highest level of rodent welfare. Recent improvements in laparoscopic equipment and techniques have enabled the adaptation of laparoscopy for rodent procedures. Laparoscopy, which is considered the gold standard for many human abdominal procedures, allows for serial biopsy collections from the same animal, results in decreased pain and tissue trauma as well as quicker postsurgical recovery, and preserves immune function in comparison to the same procedures performed by laparotomy. Laparoscopy improves rodent welfare, decreases interanimal variability, thereby reducing the number of required animals, allows for the replacement of larger species, decreases expense and improves data yield. This review article compares rodent laparotomy and laparoscopic surgical methods, and describes the utilization of laparoscopy for the development of cancer models and assessment of disease progression to improve data collection and animal welfare. In addition, currently available rodent laparoscopic equipment and instrumentation are presented.
Maternal separation and gastrointestinal transit time in neonate rats
Authors: Davis Laura D R , Spencer William J , Mack David R , Altosaar Illimar
Published: August 2011

Gastrointestinal transit times (Gltts) were compared in separate litters of 10- and 15-day-old Sprague Dawley rats using barium sulphate. By tracking the leading front of the bolus on radiographs, the gastrocaecal transit times in pups were estimated. To measure the total Gltt, the duration from orogastric gavage until an observable defecation of barium sulphate was recorded. The gastrocaecal times for 10-day-old pups maintained with their dam ( n = 5) ranged from 4–5 h and those removed from the dam ranged from 2.5–5 h. For 15-day-old pups with their dam ( n = 6) and without dam ( n = 5), gastrocaecal times ranged from 4–6 h and 3.5–5 h, respectively. Ten-day-old pups that remained with the dam had a Gltt of 13.8 ± 0.9 h and those kept in the absence of the dam had a time of 9.3 ± 0.7 h. This decrease ( P < 0.05) in Gltt in the absence of the dam was age-dependent in 10-day-old pups, and was not observed ( P > 0.05) in 15-day-old pups. The results provide a basis, for the design of future studies involving neonate rat metabolism, to include maternal presence.
Sensory Input Regulates Spatial and Subtype-Specific Patterns of Neuronal Turnover in the Adult Olfactory Bulb
Authors: Sawada Masato , Kaneko Naoko , Inada Hiroyuki , Wake Hiroaki , Kato Yasuko , Yanagawa Yuchio , Kobayashi Kazuto , Nemoto Tomomi , Nabekura Junichi , Sawamoto Kazunobu
Published: August 2011

Throughout life, new neurons are added and old ones eliminated in the adult mouse olfactory bulb. Previous studies suggested that olfactory experience controls the process by which new neurons are integrated into mature circuits. Here we report novel olfactory-experience-dependent mechanisms of neuronal turnover. Using two-photon laser-scanning microscopy and sensory manipulations in adult live mice, we found that the neuronal turnover was dynamically controlled by olfactory input in a neuronal subtype-specific manner. Olfactory input enhanced this turnover, which was characterized by the reiterated use of the same positions in the glomeruli by new neurons. Our results suggest that olfactory-experience-dependent modification of neuronal turnover confers structural plasticity and stability on the olfactory bulb.
Degeneracy and Neuromodulation among Thermosensory Neurons Contribute to Robust Thermosensory Behaviors inCaenorhabditis elegans
Authors: Beverly Matthew , Anbil Sriram , Sengupta Piali
Published: August 2011

Animals must ensure that they can execute behaviors important for physiological homeostasis under constantly changing environmental conditions. The neural mechanisms that regulate this behavioral robustness are not well understood. The nematodeCaenorhabditis elegansthermoregulates primarily via modulation of navigation behavior. Upon encountering temperatures higher than its cultivation temperature (Tc),C. elegansexhibits negative thermotaxis toward colder temperatures using a biased random walk strategy. We find thatC. elegansexhibits robust negative thermotaxis bias under conditions of varyingTcand temperature ranges. By cell ablation and cell-specific rescue experiments, we show that the ASI chemosensory neurons are newly identified components of the thermosensory circuit, and that different combinations of ASI and the previously identified AFD and AWC thermosensory neurons are necessary and sufficient under different conditions to execute a negative thermotaxis strategy. ASI responds to temperature stimuli within a defined operating range defined byTc, and signaling from AFD regulates the bounds of this operating range, suggesting that neuromodulation among thermosensory neurons maintains coherence of behavioral output. Our observations demonstrate that a negative thermotaxis navigational strategy can be generated via different combinations of thermosensory neurons acting degenerately, and emphasize the importance of defining context when analyzing neuronal contributions to a behavior.
Mild Sensory Stimulation Reestablishes Cortical Function during the Acute Phase of Ischemia
Authors: Lay Christopher C. , Davis Melissa F. , Chen-Bee Cynthia H. , Frostig Ron D.
Published: August 2011

When delivered within 1 and in most cases 2 h of permanent middle cerebral artery occlusion (pMCAO), mild sensory stimulation (intermittent single whisker stimulation) was shown to be completely neuroprotective 24 h after pMCAO in a rodent model of ischemic stroke, according to assessment with multiple techniques (Lay et al., 2010). The acute effect of stimulation treatment on the ischemic cortex, however, has yet to be reported. Here we characterize cortical function and perfusion during the 120 min whisker stimulation period in four experimental groups with treatment initiated 0, 1, 2 (protected groups), or 3 h (unprotected group) post-pMCAO using multiple techniques. According to functional imaging, a gradual return of evoked whisker functional representation to baseline levels was initiated with treatment onset and completed within the treatment period. Evoked neuronal activity and reperfusion to the ischemic area also showed a gradual recovery in protected animals. Surprisingly, a similar recovery profile was observed in response to treatment in all protected animals, regardless of treatment onset time. Nonstimulated pMCAO control group data demonstrate that reperfusion is not spontaneous. This makes the complete protection observed in the majority of animals stimulated at 2 h post-pMCAO even more surprising, as these animals recovered despite having been in a severely ischemic state for two full hours. In summary, when delivered within a 2 h window post-pMCAO, whisker stimulation treatment initiated reperfusion and a gradual recovery of cortical function that was completed or nearly completed within the treatment period.
Movement Observation Improves Early Consolidation of Motor Memory
Authors: Zhang Xue , de Beukelaar Toon T. , Possel Jessy , Olaerts Marie , Swinnen Stephan P. , Woolley Daniel G. , Wenderoth Nicole
Published: August 2011

Practicing a motor task can induce neuroplastic changes in the human primary motor cortex (M1) that are subsequently consolidated, leading to a stable memory trace. Currently, little is known whether early consolidation, tested several minutes after skill acquisition, can be improved by behavioral interventions. Here we test whether movement observation, known to evoke similar neural responses in M1 as movement execution, can benefit the early consolidation of new motor memories. We show that observing the same type of movement as that previously practiced (congruent movement stimuli) substantially improves performance on a retention test 30 min after training compared with observing either an incongruent movement type or control stimuli not showing biological motion. Differences in retention following observation of congruent, incongruent, and control stimuli were not found when observed 24 h after initial training and neural evidence further confirmed that, unlike motor practice, movement observation alone did not induce plastic changes in the motor cortex. This time-specific effect is critical to conclude that movement observation of congruent stimuli interacts with training-induced neuroplasticity and enhances early consolidation of motor memories. Our findings are not only of theoretical relevance for memory research, but also have great potential for application in clinical settings when neuroplasticity needs to be maximized.
Influence of the pre-saturation of recycled coarse concrete aggregates on concrete properties
Authors: Ferreira Luis , de Brito Jorge , Barra Marilda
Published: August 2011

The properties of structural concrete which incorporates recycled coarse concrete aggregates (RCCA) may be affected by the RCCA's properties, especially in terms of water absorption, if no technological control methods are adopted in its production. Based on the knowledge of RCCA's water absorption behaviour, this research is aimed at determining the influence of the pre-saturation of the RCCA method on concrete's fresh and hardened properties, compared with a conventional concrete and a recycled aggregates concrete produced using the mixing water compensation method. Both methods can be easily adopted at concrete plants or construction sites. For the establishment of the pre-saturation method procedure, RCCA absorption was thoroughly characterised. A reference concrete and three mixes with replacement ratios of 20%, 50% and 100% of natural coarse aggregates by RCCA were produced, for each method. Tests were performed to determine slump, density, compressive strength, elasticity modulus, shrinkage, water absorption by immersion and capillary water absorption; the surfaces of the mixes were also observed with a magnifying glass. Results showed that mixes produced with the pre-saturation method exhibited slightly worse fresh and hardened properties, and therefore it is concluded that both the pre-saturation method and the mixing water compensation method can be adopted.
A simple plant mutation abets a predator‐diversity cascade
Authors: Northfield Tobin D. , Snyder William E. , Snyder Gretchen B. , Eigenbrode Sanford D.
Published: August 2011

Resource consumption often increases with greater consumer biodiversity. This could result either from complementarity among consumers or the inclusion of particular key species, and it is often difficult to differentiate between these two mechanisms. We exploited a simple plant mutation (reduced production of surface waxes) to alter foraging within a community of aphid predators, and thus perhaps shift the nature of resulting predator diversity effects. We found that greater predator species richness dramatically increased prey suppression and plant biomass only on mutant, reduced‐wax pea plants (Pisum sativum). On pea plants from a sister line with wild type, waxier plant surfaces, predator species richness did not influence predators' impacts on herbivores or plants. Thus, a change in plant surface structure acted to turn on, or off, the cascading effects of predator diversity. Greater predator richness encouraged higher densities of true predators but did not lead to greater reproduction by a parasitoid, Aphidius ervi; fecundity of each natural enemy species was similar for the two plant types. Behavioral observations indicated that although A. ervi was less likely to forage within species‐rich predator communities, low‐wax plants mitigated this interference by encouraging generally greater A. ervi foraging and thus high rates of aphid dislodgement (aphids dropped from plants to escape A. ervi, but not the other predators). Thus, only species‐rich, low‐wax plants simultaneously encouraged strong species‐specific effects of A. ervi, and strong complementarity among the other predator species. In summary, our study provides evidence that diversity effects in predator assemblages are sensitive to habitat characteristics. Further, we show that a simple plant morphological trait, controlled by a single gene mutation, can dramatically alter the cascading effects of predator species richness on herbivores and plants.
Calculation of ceramic pot filter hydraulic conductivity using falling-head data
Authors: Elmore A. C. , Fahrenholtz W. G. , Glauber L. G. , Sperber A. N.
Published: August 2011

Flowrate is used as a predictor of ceramic pot filter (CPF) disinfection effectiveness, and the relationship between flowrate and porosity has been examined in several studies. However, hydraulic conductivity, not porosity, is the constant of proportionality that describes flow through porous media. Equations have been developed to estimate the hydraulic conductivity of CPF side walls and bottom as well an effective overall hydraulic conductivity. The equations are intended to be used with falling head data that may be collected in the field. The results of flowrate testing and open porosity testing using experimental CPFs provide preliminary indication that hydraulic conductivity is a better predictor of flowrate relative to open porosity. The results of the preliminary testing suggest that the shape and orientation of open pore space may have significant impact on filter flowrates, and that filter researchers and producers may want to evaluate the material used to form the pores as well as the impact of the filter formation process on any spatial orientation of open pore space. A better understanding of hydraulic conductivity may improve the production efficiency of filter factories which could make lower cost filters available to a greater number of households in developing areas.
Hybrid TiO2 photocatalytic oxidation and ultrafiltration for humic acid removal and membrane fouling control
Authors: Bai Hongwei , Sun Darren Delai
Published: August 2011

Hybrid UV/TiO2 photocatalytic oxidation (PCO) and ultrafiltration (UF) process (PCO-UF) were used to remove humic acid (HA) and control membrane fouling. The PCO-UF process showed advantages in terms of higher removal rate of HA, higher permeate flux and less membrane fouling over UF alone and PCO alone on HA removal and membrane fouling control. Membrane material and pH of feed water were shown to be the influence on the performance of PCO-UF process. It was observed that higher pH of HA feed water and a hydrophobic membrane lead to better removal of HA with relatively higher permeate flux. The experimental results in this study demonstrated that 100 kDa ultraflic UF membrane and pH 9 of HA feed water would be the optimal choice for HA removal in the combined PCO-UF process.
Water Safety Plan demonstration projects in Latin America and the Caribbean: lessons from the field
Authors: Rinehold Angella , Corrales Lana , Medlin Elizabeth , Gelting Richard J.
Published: August 2011

A Water Safety Plan (WSP) is a preventive, risk management approach to ensure drinking water safety. This emerging methodology is being increasingly applied in both industrialized and lower income countries worldwide. In 2006, the U.S. Centers for Disease Control and Prevention (CDC) and other local, national, and international partners in Latin America and the Caribbean (LAC) initiated a series of WSP demonstration projects. The objectives were to raise WSP awareness, build capacity, and promote adoption of the WSP approach while identifying those factors that aid or hinder water safety planning efforts in resource-challenged settings. This paper presents eleven lessons learned from these WSP demonstration projects, including the importance of assembling a well-supported interagency team, long-term commitment to WSP implementation, adherence to a water quality monitoring plan, and determining how WSP impacts will be evaluated prior to WSP initiation. To assist in supporting future WSP activity in the region, this paper shares experiences that led to these successes, challenges, and lessons learned.
Correlation between the degree of conversion and the elution of leachable components from dental resin-based cements
Authors: Obradovic-Djuricic Kosovka , Medic Vesna , Radisic Marina , Lausevic Mila
Published: August 2011

This study examined the possible correlation between the degree of conversion
(DC) and the amount of substances eluted from three commercial cured
resin-based cements. The DC of the various resin-based cements was measured
by Raman spectroscopy, while the quantity of unreacted monomers released from
the cement matrix (triethylene glycol dimethacrylate, TEGDMA, urethane
dimethacrylate, UDMA, 2- hydroxyethyl methacrylate, HEMA and bis phenol A)
was determined by high pressure liquid chromatography (HPLC). The obtained
results, after multiple statistical evaluation (one way ANOVA, LSD post hoc
test), showed no significant differences in the DC values between the resin
cements. On the contrary, the results of the HPLC analysis depicted
statistically significant differences between the three materials with
respect to the amount of leached monomers. In addition, no correlation
between the DC and the amount of eluted substances from the tested cured
composite cements was found.
Copper(II) and lead(II) complexation by humic acid and humic-like ligands
Authors: Kostic Ivana , Andjelkovic Tatjana , Nikolic Ruzica , Bojic Aleksandar , Purenovic Milovan , Blagojevic Srdjan , Andjelkovic Darko
Published: August 2011

The stability of metal-humate complexes is an important factor determining
and predicting speciation, mobility and bioavailability of heavy metals in
the environment. A comparative investigation of the complexation of Cu(II)
and Pb(II) with humic acid and humic-like ligands, such as benzoic and
salicylic acid, was performed. The analysis was realized at pH 4.0, a
temperature of 25?C and at an ionic strength of 0.01 (NaCl) using the
Schubert ion-exchange method and its modified form. The stability constants
were calculated from the experimental data by the Schubert method for
complexes with benzoic and humic acid. A modified Schubert method was used
for the determination of the stability constants of the complexes with
salicylic acid. It was found that Cu(II) and Pb(II) form mononuclear
complexes with benzoic and humic acid while with salicylic acid both metals
form polynuclear complexes. The results indicate that Pb(II) has a higher
binding ability than Cu(II) to all the investigated ligands. The
Cu(II)-salicylate and Pb(II)-salicylate complexes showed noticeable higher
stability constants compared with their complexes with humic acid, while the
stabilities of the complexes with benzoic acid differed less. Salicylic and
benzoic acids as humic-like ligands can be used for setting the range of
stability constants of humic complexes with Cu(II) and Pb(II).
Protein glycosylation in infectious disease pathobiology and treatment
Authors: Vigerust David
Published: August 2011

A host of bacteria and viruses are dependent on O-linked and N-linked glycosylation to perform vital biological functions. Pathogens often have integral proteins that participate in host-cell interactions such as receptor binding and fusion with host membrane. Fusion proteins from a broad range of disparate viruses, such as paramyxovirus, HIV, ebola, and the influenza viruses share a variety of common features that are augmented by glycosylation. Each of these viruses contain multiple glycosylation sites that must be processed and modified by the host post-translational machinery to be fusogenically active. In most viruses, glycosylation plays a role in biogenesis, stability, antigenicity and infectivity. In bacteria, glycosylation events play an important role in the formation of flagellin and pili and are vitally important to adherence, attachment, infectivity and immune evasion. With the importance of glycosylation to pathogen survival, it is clear that a better understanding of the processes is needed to understand the pathogen requirement for glycosylation and to capitalize on this requirement for the development of novel therapeutics.