bluuebunny/crossref_metadata_2025_split huggingface dataset:
Does Optic Flow Explain the Firing of Grid Cells?
Authors: Raudies Florian , Mingolla Ennio , Hasselmo Michael 
Published: March 2011

Abstract*Problem.* Various cues such as vestibular, sensorimotor, or visual information can lead to the firing of grid cells recorded in entorhinal cortex of rats. A recent model uses boundary vector cells to provide information about the 2D spatial position (Barry et al., Review Neuroscience, 17, 2006). However, boundary vector cells need to know the angle and distance of the boundary wall. In contrast we study the estimation of 2D velocity and change of heading of the rat from optic flow and if this information can lead to grid cell firing.*Approach.* A simple circular cage is modeled as a 3D world and trajectories of a rat’s movement are simulated. Optic flow for a spherical camera model is calculated for regularly sampled locations on the ground of the cage. This flow information is used in a template model to estimate the rat’s 2D linear velocity and yaw rotational velocity. 2D linear velocities are integrated into the velocity controlled oscillator (VCO) model (Burgess, Hippocampus, 18, 2008) while spatial locations are taken from the original trajectory.
Result and Conclusion.
If velocity estimates are temporally integrated over ~20min the error summation by path integration prevents generation of a clear grid cell firing pattern by the VCO model. However, for short durations velocity estimates and path integration are accurate. If we assume a reset mechanism that recalibrates the spatial location of the rat grid cell firing can be achieved. Different reset intervals were simulated and the grid score for the firing pattern was calculated. For a reset interval longer than one minute this grid score decreases rapidly. We conclude that grid cell firing is not generated only by optic flow, but that a recalibration of the spatial position using cues other than optic flow occurs at least every minute.Supported by CELEST (NSF SMA-0835976).
Intimate boundaries: Therapists’ perception and experience of erotic transference within the therapeutic relationship
Authors: Rodgers Nicky M. 
Published: March 2011

AbstractAim: This study explored therapists’ understanding and experiences of erotic transference within therapeutic relationships. Method: A small‐scale qualitative research project was undertaken with six therapists working within different counselling contexts. Data was collected through semi‐structured face‐to‐face interviews, and an Interpretative Phenomenological Analysis used for analysis of individual perception and experience. Findings: All participants had experienced what they understood to be erotic transference and/or sexual and loving feelings within therapy. There was little differentiation between the two phenomena, and both were often referred to interchangeably. There were contradictory views as to whether using the phenomena would be beneficial to client work, but there was a strong motivation to learn more about it. Therapists who encountered sexual attraction within therapy experienced feelings including shame and embarrassment. Supervisory support was seen to be beneficial. Implications/conclusion: The importance for therapists to acknowledge a lack of clarity that exists around the understanding of erotic transference and its relationship to sexual attraction within therapy is noted. Also, a recognition that better access to training regarding erotic transference and sexual responsibility within client relationships might be helpful to therapists in their work.
Aquaporin 5 Gene Promoter −1364A/C Polymorphism Associated with 30-day Survival in Severe Sepsis
Authors: Adamzik Michael , Frey Ulrich H. , Möhlenkamp Stephan , Scherag André , Waydhas Christian , Marggraf Günther , Dammann Marc , Steinmann Jörg , Siffert Winfried , Peters Jürgen 
Published: March 2011

Background
Because the aquaporin (AQP) 5 promoter -1364A/C polymorphism is associated with altered AQP5 expression, this association could have an impact on key mechanisms in sepsis, such as cell migration, activity of the rennin-angiotensin- aldosterone system (RAAS), and water transport across biologic membranes. Therefore, we tested the hypothesis that the AQP5 promoter -1364A/C polymorphism is associated with increased 30-day survival in severe sepsis.

Methods
In a prospective study, adults with severe sepsis (N = 154) were genotyped for the AQP5 promoter -1364A/C polymorphism. The clinical endpoint was 30-day survival. Kaplan-Meier plots and multivariate proportional hazard analyses were used to evaluate the relationship between genotypes and clinical outcomes.

Results
Thirty-day survival was significantly associated with AQP5 -1364A/C genotypes (P = 0.001). Survival rates were 57% for AA genotypes (n = 90) but 83% for combined AC/CC genotypes (56 vs. 8, respectively). Multivariate proportional hazard analysis including sex, age, Simplified Acute Physiology Score II, Sequential Organ Failure Assessment score, body mass index, necessity for continuous hemofiltration/dialysis, concentrations of plasma angiotensin II, serum aldosterone, C-reactive protein, and interleukin 6 as covariates revealed the AQP5 -1364A/C polymorphism as a strong and independent prognostic factor for 30-day survival. In this analysis, homozygous AA subjects were at high risk for death within 30 days (hazard ratio, 3.59; 95% CI, 1.47-8.80; P = 0.005) compared with AC/CC genotypes.

Conclusion
The C-allele of the AQP5 -1364A/C polymorphism is associated with increased 30-day survival in patients with severe sepsis. This finding suggests the importance of variations in expression of AQP5 channels in severe sepsis.
Increased Peak Postoperative B-type Natriuretic Peptide Predicts Decreased Longer-term Physical Function after Primary Coronary Artery Bypass Graft Surgery
Authors: Fox Amanda A. , Marcantonio Edward R. , Collard Charles D. , Thoma Mathis , Perry Tjorvi E. , Shernan Stanton K. , Muehlschlegel Jochen D. , Body Simon C. 
Published: March 2011

Background
Increased peak postoperative B-type natriuretic peptide (BNP) is associated with increased major adverse cardiovascular events and all-cause mortality after coronary artery bypass graft (CABG) surgery. Whether increased postoperative BNP predicts worse postdischarge physical function (PF) is unknown. We hypothesized that peak postoperative BNP associates with PF assessed up to 2 yr after CABG surgery, even after adjusting for clinical risk factors. including preoperative PF.

Methods
This two-institution prospective cohort study included patients undergoing primary CABG surgery with cardiopulmonary bypass. Short Form-36 questionnaires were administered to subjects preoperatively and 6 months, 1 yr, and 2 yr postoperatively. Short Form-36 PF domain scores were calculated using the Short Form-36 norm-based scoring algorithm. Plasma BNP concentrations measured preoperatively and on postoperative days 1-5 were log(10) transformed before analysis. To determine whether peak postoperative BNP independently predicts PF scores 6 months through 2 yr after CABG surgery, multivariable longitudinal regression analysis of the postoperative PF scores was performed, adjusting for important clinical risk factors.

Results
A total of 845 subjects (mean ± SD age, 65 ± 10 yr) were analyzed. Peak postoperative BNP was significantly associated with postoperative PF (effect estimate for log(10) peak BNP, -7.66 PF score points [95% CI, -9.68 to -5.64]; P = <0.0001). After multivariable adjustments, peak postoperative BNP remained independently associated with postoperative PF (effect estimate for log(10) peak BNP, -3.06 PF score points [95% CI, -5.15 to -0.97]; P = 0.004).

Conclusions
Increased peak postoperative BNP independently associates with worse longer-term PF after primary CABG surgery. Future studies are needed to determine whether medical management targeted toward reducing increased postoperative BNP can improve PF after CABG surgery.
Chronic β Blockade Is Associated with a Better Outcome after Elective Noncardiac Surgery than Acute β Blockade
Authors: Ellenberger Christoph , Tait Gordon , Beattie W. Scott 
Published: March 2011

Background
Current guidelines on perioperative care recommend the prophylactic use of β blockers in high-risk patients undergoing noncardiac surgery. However, recent studies show that, in some instances, perioperative β blockade can cause harm. Furthermore, chronic β blockade, titrated to effect before surgery, may be superior to acute perioperative β blockade. The primary objective of this study was to compare major acute cardiac outcomes in patients who underwent surgery with chronic β blocker therapy with those in patients with acute β-blocker therapy.

Methods
Data were collected for 10,691 consecutive patients undergoing elective noncardiac surgery between April 1, 2008, and April 30, 2010. Propensity scores, estimating the probability of receiving a preoperative β blocker, were calculated to match (1:1) the patients with acute and chronic β-blocker therapy. The primary outcome was a composite of myocardial infarction, nonfatal cardiac arrest, and perioperative mortality. The rate of cardiac events was compared in the matched cohorts.

Results
A total of 962 patients were chronically treated with a β blocker before surgery; in 436 patients, the β blocker was administrated acutely. Propensity score matching created 301 patient pairs who were well-balanced for major comorbidities, concomitant drug use, and type of surgery. The primary outcome was observed in 9 (3.0%) chronic versus 24 (8.0%) acute β-blocked patients (relative risk, 2.67; 95% CI, 1.27-5.60; P = 0.011).

Conclusions
Acute β blockade, initiated within the first 2 days after surgery, was associated with worse cardiac outcome compared with a matched cohort of patients who underwent surgery on chronic β blockade. These results should be validated in a larger prospective trial.
Ventilatory Protective Strategies during Thoracic Surgery
Authors: Kozian Alf , Schilling Thomas , Schütze Hartmut , Senturk Mert , Hachenberg Thomas , Hedenstierna Göran 
Published: March 2011

Background
The increased tidal volume (V(T)) applied to the ventilated lung during one-lung ventilation (OLV) enhances cyclic alveolar recruitment and mechanical stress. It is unknown whether alveolar recruitment maneuvers (ARMs) and reduced V(T) may influence tidal recruitment and lung density. Therefore, the effects of ARM and OLV with different V(T) on pulmonary gas/tissue distribution are examined.

Methods
Eight anesthetized piglets were mechanically ventilated (V(T) = 10 ml/kg). A defined ARM was applied to the whole lung (40 cm H(2)O for 10 s). Spiral computed tomographic lung scans were acquired before and after ARM. Thereafter, the lungs were separated with an endobronchial blocker. The pigs were randomized to receive OLV in the dependent lung with a V(T) of either 5 or 10 ml/kg. Computed tomography was repeated during and after OLV. The voxels were categorized by density intervals (i.e., atelectasis, poorly aerated, normally aerated, or overaerated). Tidal recruitment was defined as the addition of gas to collapsed lung regions.

Results
The dependent lung contained atelectatic (56 ± 10 ml), poorly aerated (183 ± 10 ml), and normally aerated (187 ± 29 ml) regions before ARM. After ARM, lung volume and aeration increased (426 ± 35 vs. 526 ± 69 ml). Respiratory compliance enhanced, and tidal recruitment decreased (95% vs. 79% of the whole end-expiratory lung volume). OLV with 10 ml/kg further increased aeration (atelectasis, 15 ± 2 ml; poorly aerated, 94 ± 24 ml; normally aerated, 580 ± 98 ml) and tidal recruitment (81% of the dependent lung). OLV with 5 ml/kg did not affect tidal recruitment or lung density distribution. (Data are given as mean ± SD.)

Conclusions
The ARM improves aeration and respiratory mechanics. In contrast to OLV with high V(T), OLV with reduced V(T) does not reinforce tidal recruitment, indicating decreased mechanical stress.
Genomic Analysis of Circadian Clock-, Light-, and Growth-Correlated Genes Reveals PHYTOCHROME-INTERACTING FACTOR5 as a Modulator of Auxin Signaling in Arabidopsis
Authors: Nozue Kazunari , Harmer Stacey L. , Maloof Julin N. 
Published: March 2011

AbstractPlants exhibit daily rhythms in their growth, providing an ideal system for the study of interactions between environmental stimuli such as light and internal regulators such as the circadian clock. We previously found that two basic loop-helix-loop transcription factors, PHYTOCHROME-INTERACTING FACTOR4 (PIF4) and PIF5, integrate light and circadian clock signaling to generate rhythmic plant growth in Arabidopsis (Arabidopsis thaliana). Here, we use expression profiling and real-time growth assays to identify growth regulatory networks downstream of PIF4 and PIF5. Genome-wide analysis of light-, clock-, or growth-correlated genes showed significant overlap between the transcriptomes of clock-, light-, and growth-related pathways. Overrepresentation analysis of growth-correlated genes predicted that the auxin and gibberellic acid (GA) hormone pathways both contribute to diurnal growth control. Indeed, lesions of GA biosynthesis genes retarded rhythmic growth. Surprisingly, GA-responsive genes are not enriched among genes regulated by PIF4 and PIF5, whereas auxin pathway and response genes are. Consistent with this finding, the auxin response is more severely affected than the GA response in pif4 pif5 double mutants and in PIF5-overexpressing lines. We conclude that at least two downstream modules participate in diurnal rhythmic hypocotyl growth: PIF4 and/or PIF5 modulation of auxin-related pathways and PIF-independent regulation of the GA pathway.
Comparative evaluation of seed coat dormancy breaking treatments in Stylosanthes seabrana
Authors: Anand A. , Bhardwaj J. , Nagarajan S. 
Published: March 2011

AbstractThe efficiency of microwave treatment in breaking the hard seed coat dormancy in Stylosanthes seabrana was compared with three other conventional methods including mechanical scarification, hot water treatment (100°C for 1 min) and acid scarification (5 min). The microwave treatment was as efficient in breaking hard seed coat dormancy as the hot water treatment. The ranking of treatments followed the order microwave ≥ hot water ≥ acid > mechanical scarification > control. The electrical conductivity of microwave‐treated seeds, although less than that of hot water, was greater than untreated control seeds, indicating increased permeability of the seed coat for water uptake. Seedling vigour, based on seedling length, was also similar for these treatments. Respiration was found to be higher in microwave‐treated seeds. Although levels of food reserves were not measured, future studies could hypothesize that increased imbibition of water in microwave‐treated seeds could cause a faster breakdown of food‐reserve material that is supplied to the germinating seed, resulting in increased evolution of CO2 through respiration. Scanning electron micrographs indicated the appearance of cracks and blisters on the seed surface of microwave‐treated seeds. These are most likely the sites of water entry during imbibition.
Plant and soil responses to nitrogen and phosphorus fertilization of bromegrass‐dominated haylands in Saskatchewan, Canada
Authors: Lkhagvasuren B. , Schoenau J. J. , Anderson D. W. , Malhi S. S. 
Published: March 2011

AbstractField experiments were conducted at three different sites in Saskatchewan, Canada (Colonsay, Vanscoy and Rosthern) over two years (2005 and 2006) to determine the effects of dribble‐banded and coulter‐injected liquid fertilizer applied in the spring of 2005 at 56, 112 and 224 kg N ha−1 with and without P at 28 kg P2O5 ha−1. The three sites were unfertilized, 7‐ to 8‐year old stands of mainly meadow bromegrass (Bromus riparius)‐dominated haylands. All fertilization treatments produced significantly (P ≤ 0·05) higher dry matter yield than the control in the year of application at the three Saskatchewan sites. There was no significant difference between the two application methods (surface dribble band vs. coulter injected) for any fertilizer treatments. The addition of 28 kg P2O5 ha−1 P fertilizer along with the N fertilizer did not have a significant effect on yield in most cases. In the year of application, increasing N rates above 56 kg N ha−1 did not significantly increase yield over the 56 kg N ha−1 rate in most cases, but did increase N concentration, N uptake and protein concentration. A significant residual effect was found in the high N‐rate treatments in 2006, with significantly higher yield and N uptake. In 2005, the forage N and P uptake in the fertilized treatments were significantly higher than the control in all cases. The N uptake at the three Saskatchewan sites increased with increasing N rate up to the high rate of 224 kg N ha−1, although the percent recovery of applied N decreased with increasing rate. The P fertilization with 28 kg P2O5 ha−1 also increased P uptake. Overall, rates of fertilizer of approximately 56 kg N ha−1 appear to be sufficient to produce nearly maximum forage yield and protein concentration of the grass in the year of application.
A systematic review of mentoring nursing students in clinical placements
Authors: Jokelainen Merja , Turunen Hannele , Tossavainen Kerttu , Jamookeeah David , Coco Kirsi 
Published: March 2011

Aim and objective.  This systematic review describes mentoring of nursing students in clinical placements.Background.  Mentoring in nursing has been widely investigated, but mentoring among students has remained vague. There is no universal agreement on student mentoring in nursing placements; therefore, mentoring approaches vary. A unified description of student mentoring is needed to ensure the quality of placement learning in nursing organisations.Design.  Systematic review.Method.  The data were collected from nursing research articles over 20 years (1986–2006). The articles (n = 23) were analysed using inductive content analysis.Results.  Mentoring of nursing students in clinical placements was described according to two themes: (1) facilitating nursing students’ learning by creating supportive learning environments and enabling students’ individual learning processes, (2) strengthening students’ professionalism by empowering the development of their professional attributes and identities and enhancing attainment of students’ professional competence in nursing.Discussion.  This description of student mentoring in nursing clinical placements integrates environmental, collegial, pedagogical and clinical attributes. To ensure effective student mentoring, an individual mutual relationship is important, but also essential is organisation and management to provide adequate resources and systematic preparation for mentors.Conclusions.  The description of student mentoring needs to be systematically reviewed to reflect changes in nursing and education and compared within related concepts to achieve and maintain a workable description. A clear and systematic strategy for student mentoring in nursing organisations could be one opportunity to enhance recruitment of nursing students to the workforce.Relevance to clinical practice.  A unified description of student mentoring will help improve the quality of placement learning opportunities and support for students, also for exchange students. A clear description of student mentoring enables the development of systematic provisions for mentoring of nursing students in placements and adequate mentor preparation programmes for nurses.
Direct evidence of surface infestation of seeds and tubers by Plasmodiophora brassicae and quantification of spore loads
Authors: Rennie D. C. , Manolii V. P. , Cao T. , Hwang S. F. , Howard R. J. , Strelkov S. E. 
Published: March 2011

Using quantitative PCR, DNA of Plasmodiophora brassicae, the causal agent of clubroot, was detected and quantified on canola, pea and wheat seeds, as well as on potato tubers, all harvested from clubroot‐infested fields in Alberta, Canada. Quantifiable levels of infestation were found on seven of the 46 samples analysed, and ranged from <1·0 × 103 to 3·4 × 104 resting spores per 10 g seeds; the vast majority (80–100%) of resting spores on these samples were viable, as determined by Evan’s blue vital staining. However, the levels of infestation found were generally lower than that required to cause consistent clubroot symptoms in greenhouse plant bioassays. While the occurrence of P. brassicae resting spores on seeds and tubers harvested from clubroot‐infested fields suggests that seedborne dissemination of this pathogen is possible, practices such as commercial seed cleaning may be sufficient to effectively mitigate this risk.
Phylogenetic and morphological identification of Colletotrichum boninense: a novel causal agent of anthracnose in avocado
Authors: Silva‐Rojas H. V. , Ávila‐Quezada G. D. 
Published: March 2011

In recent years, anthracnose has become a significant disease affecting avocado fruit in the state of Michoacan, Mexico, where it significantly reduces fruit quality and commercial yield. Anthracnose has been assumed to involve Colletotrichum gloeosporioides and C. acutatum as causal agents. However, because of the increasing incidence of anthracnose, a more precise identification of the Colletotrichum spp. involved in this disease has become desirable. During the years 2004–2007, avocado fruits of different sizes exhibiting brown‐black and reddish spots on the pericarp and soft rot in the mesocarp, were gathered from orchards in nine counties. Fungal isolates were cultured on potato dextrose agar, and among these, 31 were selected for molecular, morphological and pathogenicity analyses. The molecular approaches used sequence typing of the internal transcribed spacer region and the partial nuclear large ribosomal subunit, allowing the unequivocal identification of C. gloeosporioides (71%), C. acutatum (16%) and C. boninense (13%). This last species has not been previously reported as being associated with anthracnose symptoms in avocado fruits anywhere in the world. Various morphological characteristics such as the size and shape of conidia were determined, as well as the conidial mass colour. Pathogenicity tests performed with all three species were conducted by inoculating healthy fruits. In each case, identical symptoms developed within 3 days of inoculation. Knowledge of the Colletotrichum populations in the Michoacan state, including the newly encountered avocado pathogen C. boninense, will facilitate further studies addressing the relationships between these Colletotrichum spp. and their avocado host.