Incisional hernia following colorectal cancer surgery according to suture technique: Hughes Abdominal Repair Randomized Trial (HART)

BACKGROUND

Incisional hernias cause morbidity and may require further surgery. HART (Hughes Abdominal Repair Trial) assessed the effect of an alternative suture method on the incidence of incisional hernia following colorectal cancer surgery.

METHODS

A pragmatic multicentre single-blind RCT allocated patients undergoing midline incision for colorectal cancer to either Hughes closure (double far-near-near-far sutures of 1 nylon suture at 2-cm intervals along the fascia combined with conventional mass closure) or the surgeon's standard closure. The primary outcome was the incidence of incisional hernia at 1 year assessed by clinical examination. An intention-to-treat analysis was performed.

RESULTS

Between August 2014 and February 2018, 802 patients were randomized to either Hughes closure (401) or the standard mass closure group (401). At 1 year after surgery, 672 patients (83.7 per cent) were included in the primary outcome analysis; 50 of 339 patients (14.8 per cent) in the Hughes group and 57 of 333 (17.1 per cent) in the standard closure group had incisional hernia (OR 0.84, 95 per cent c.i. 0.55 to 1.27; P = 0.402). At 2 years, 78 patients (28.7 per cent) in the Hughes repair group and 84 (31.8 per cent) in the standard closure group had incisional hernia (OR 0.86, 0.59 to 1.25; P = 0.429). Adverse events were similar in the two groups, apart from the rate of surgical-site infection, which was higher in the Hughes group (13.2 versus 7.7 per cent; OR 1.82, 1.14 to 2.91; P = 0.011).

CONCLUSION

The incidence of incisional hernia after colorectal cancer surgery is high. There was no statistical difference in incidence between Hughes closure and mass closure at 1 or 2 years.

REGISTRATION NUMBER

ISRCTN25616490 (http://www.controlled-trials.com).

Muir-Torre syndrome: a case of unusual coexisting genetic mutations

Muir-Torre syndrome (MTS) is a rare autosomal dominant geno-dermatosis that was independently described by Muir in 1967 and Torre in 1968. MTS is a phenotypic subtype of Lynch syndrome and most commonly arises due to germline mutations in mismatch repair genes. MTS manifests with at least one cutaneous neoplasm and one visceral malignancy.

935 Identification and Management of Electrolyte Abnormalities in Surgical Patients Requiring Total Parenteral Nutrition: An Audit of Current Practice at A University Hospital

Aim

Electrolyte abnormalities are a common and serious consequence of nutritional deficiencies when patients are nil-by-mouth. Timely intervention with a multidisciplinary approach is known to improve outcome. This audit aimed to assess adequacy of initial electrolyte management and timing of dietetics referral in acute surgical patients requiring total parenteral nutrition in a university hospital.

Method

A retrospective audit of all general surgery patients referred to dietetics for total parenteral nutrition between January-December 2019 was performed. The following audit standards (from the time following admission) were applied: monitoring of electrolytes every 48-hours, treatment of electrolyte abnormalities within 24-hours of discovery; and referral to the dietetics service within 48-hours of nil-by-mouth being commenced.

Results

Data from 52 patients (27 females, median age 66) were analysed. Fifty-one (98%) had electrolytes measured every 48-hours, however magnesium, phosphate and/or calcium were not measured prior to dietetics input in 9 (17%). Forty electrolyte abnormalities requiring treatment were found in 28 patients (54%), though only 18 (64%) commenced treatment within 24-hours. The most common electrolyte abnormalities not corrected within 24-hours were phosphate and calcium (50%). 46% of patients were referred to dietetics after 48-hours of nil-by-mouth status.

Conclusions

In our unit, we found that basic electrolytes were frequently monitored in patients placed nil-by-mouth, however calcium, phosphate and magnesium were often omitted prior to dietetics input, and correction of abnormalities was sometimes delayed. Introduction of a local protocol-based approach for electrolyte monitoring with streamlined dietetics referrals is likely to improve adherence to best practice.

O38: TACKING VERSUS NO TACKING IN LAPAROSCOPIC TOTALLY EXTRAPERITONEAL REPAIR OF PRIMARY INGUINAL HERNIA - A SYSTEMATIC REVIEW AND META-ANALYSIS

Introduction

The necessity of mesh fixation in laparoscopic totally extraperitoneal (TEP) inguinal hernia repair remains controversial. We performed a systematic review and meta-analysis to compare the effectiveness of mesh tacking versus no tacking in laparoscopic TEP repair for primary inguinal hernia.

Materials and Methods

PubMed, EMBASE and Cochrane databases were searched for relevant articles from inception until November 2019. All studies that compared tacking versus no tacking in TEP repairs for inguinal herniae were included. Recurrent and femoral herniae were excluded from the current analysis. The primary outcome measure was recurrence, while secondary outcomes included postoperative pain scores at discharge and at 1 month, mean operative time, length of stay and seroma rates. Random effects models were used to calculate pooled effect size estimates.

Result

Eight randomised controlled trials were included capturing 557 patients and 715 inguinal herniae. On random effects analysis, there were no significant differences between tacking and no tacking in terms of recurrence (OR 0.94, 95% CI=0.10 to 9.28, p=0.96), postoperative pain scores on discharge (Mean difference 0.82, 95% CI=-0.35 to 2.00, p=0.17) or at 1 month (Mean difference 0.53, 95% CI=-0.75 to 1.82, p=0.41), mean operative time (Mean difference 1.58 mins, 95% CI=-0.22 to 3.37, p=0.09), seroma (OR=0.70, 95% CI=0.28 to 1.74, p=0.44) or length of stay (Mean difference 0.11 days, 95% CI=-0.04 to 0.25, p=0.14).

Conclusion

Mesh tacking in laparoscopic TEP repair for primary inguinal herniae does not translate into improved postoperative outcomes and may be omitted.

Take-home message

Mesh tacking in laparoscopic TEP repair for primary inguinal herniae does not translate into improved postoperative outcomes and may be omitted.

O66: FLOW CYTOMETRIC AND RNA SEQUENCED UNCOUPLING OF TUMOUR-INFILTRATING LYMPHOCYTE CHECKPOINT EXPRESSION AND MISMATCH REPAIR STATUS IN COLORECTAL CANCER

Introduction

Selection criteria for immunotherapy with checkpoint blockade in colorectal cancer are currently based on mismatch repair status. However, intra-tumoral T cell response varies among patients with the same MMR status. Inhibitory checkpoint expression on tumour-infiltrating lymphocytes in microsatellite stable and unstable CRC is unknown.

Method

Flow cytometric analysis and single-cell RNA sequencing, using the 10x genomic platform, were performed ex vivo on tumour and uninvolved colonic tissue samples from patients undergoing surgical resection for colorectal cancer. Inhibitory checkpoint expression (PD-1) and functional status of isolated populations of TILs were analysed.

Result

Conventional and unconventional tissue-resident T cells were enriched in tumour samples compared to uninvolved healthy colonic tissue. Upregulation of PD-1 expression on TILs was observed in all patients, however the % upregulation varied among those with the same MMR status. A proportion of MSS tumours were found to have high levels of PD-1 expression, while a subset of MSI tumours had low PD-1 expression. Functional studies of cytotoxicity demonstrated varying TIL production of IFNg, TNFa and amphiregulin in patients with the same MMR status.

Conclusion

TIL profile (infiltration pattern, checkpoint expression and functional status) differs among patients with the same MMR status. A subset of ‘hot’ immunogenic MSS tumours exist that may respond to checkpoint blockade. Characterisation of TIL profile represents a more accurate method of selecting patients likely to derive benefit. Abbrev. CRC Colorectal cancer, MMR Mismatch repair, TIL Tumour-infiltrating lymphocytes, MSS Microsatellite stable, MSI Microsatellite unstable, IFNg Interferon-gamma, TNFa Tumour necrosis factor alpha

Take-home message

A subset of immunogenic microsatellite stable colorectal tumours exist that may respond to checkpoint blockade. Mismatch repair status alone does not accurately predict response to immunotherapy.

Safety and immunogenicity of the α-synuclein active immunotherapeutic PD01A in patients with Parkinson's disease: a randomised, single-blinded, phase 1 trial

BACKGROUND

Robust evidence supports the role of α-synuclein pathology as a driver of neuronal dysfunction in Parkinson's disease. PD01A is a specific active immunotherapy with a short peptide formulation targeted against oligomeric α-synuclein. This phase 1 study assessed the safety and tolerability of the PD01A immunotherapeutic in patients with Parkinson's disease.

METHODS

We did a first-in-human, randomised, phase 1 study of immunisations with PD01A, followed by three consecutive study extensions. Patients aged 45-65 years with a clinical diagnosis of Parkinson's disease (≤4 years since diagnosis and Hoehn and Yahr Stage 1 to 2), imaging results (dopamine transporter single photon emission CT and MRI) consistent with their Parkinson's disease diagnosis, and on stable doses of Parkinson's disease medications for at least 3 months were recruited at a single private clinic in Vienna, Austria. Patients were randomly assigned (1:1), using a computer-generated sequence with varying block size, to receive four subcutaneous immunisations with either 15 μg or 75 μg PD01A injected into the upper arms and followed up initially for 52 weeks, followed by a further 39 weeks' follow-up. Patients were then randomly assigned (1:1) again to receive the first booster immunisation at 15 μg or 75 μg and were followed up for 24 weeks. All patients received a second booster immunisation of 75 μg and were followed up for an additional 52 weeks. Patients were masked to dose allocation. Primary (safety) analyses included all treated patients. These four studies were registered with EU Clinical Trials Register, EudraCT numbers 2011-002650-31, 2013-001774-20, 2014-002489-54, and 2015-004854-16.

FINDINGS

32 patients were recruited between Feb 14, 2012, and Feb 6, 2013, and 24 were deemed eligible and randomly assigned to receive four PD01A priming immunisations. One patient had a diagnosis change to multiple system atrophy and was withdrawn and two patients withdrew consent during the studies. 21 (87%) of 24 patients received all six immunisations and completed 221-259 weeks in-study (two patients in the 15 μg dose group and one patient in the 75 μg dose group discontinued). All patients experienced at least one adverse event, but most of them were considered unrelated to study treatment (except for transient local injection site reactions, which affected all but one patient). Serial MRI assessments also ruled out inflammatory processes. Systemic treatment-related adverse events were fatigue (n=4), headache (n=3), myalgia (n=3), muscle rigidity (n=2), and tremor (n=2). The geometric group mean titre of antibodies against the immunising peptide PD01 increased from 1:46 at baseline to 1:3580 at week 12 in the 15 μg dose group, and from 1:76 to 1:2462 at week 12 in the 75 μg dose group. Antibody titres returned to baseline over 2 years, but could be rapidly reactivated after booster immunisation from week 116 onwards, reaching geometric group mean titres up to 1:20218.

INTERPRETATION

Repeated administrations of PD01A were safe and well tolerated over an extended period. Specific active immunotherapy resulted in a substantial humoral immune response with target engagement. Phase 2 studies are needed to further assess the safety and efficacy of PD01A for the treatment of Parkinson's disease.

FUNDING

AFFiRiS, Michael J Fox Foundation.

Erratum: Evolution of π^{0} Suppression in Au+Au Collisions from sqrt[s_{NN}]=39 to 200 GeV [Phys. Rev. Lett. 109, 152301 (2012)]

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

IL-10 signaling in dendritic cells controls IL-1β-mediated IFNγ secretion by human CD4+ T cells: relevance to inflammatory bowel disease

Uncontrolled interferon γ (IFNγ)-mediated T-cell responses to commensal microbiota are a driver of inflammatory bowel disease (IBD). Interleukin-10 (IL-10) is crucial for controlling these T-cell responses, but the precise mechanism of inhibition remains unclear. A better understanding of how IL-10 exerts its suppressive function may allow identification of individuals with suboptimal IL-10 function among the heterogeneous population of IBD patients. Using cells from patients with an IL10RA deficiency or STAT3 mutations, we demonstrate that IL-10 signaling in monocyte-derived dendritic cells (moDCs), but not T cells, is essential for controlling IFNγ-secreting CD4⁺ T cells. Deficiency in IL-10 signaling dramatically increased IL-1β release by moDCs. IL-1β boosted IFNγ secretion by CD4⁺ T cells either directly or indirectly by stimulating moDCs to secrete IL-12. As predicted a signature of IL-10 dysfunction was observed in a subgroup of pediatric IBD patients having higher IL-1β expression in activated immune cells and macroscopically affected intestinal tissue. In agreement, reduced IL10RA expression was detected in peripheral blood mononuclear cells and a subgroup of pediatric IBD patients exhibited diminished IL-10 responsiveness. Our data unveil an important mechanism by which IL-10 controls IFNγ-secreting CD4⁺ T cells in humans and identifies IL-1β as a potential classifier for a subgroup of IBD patients.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions

The PHENIX collaboration presents first measurements of low-momentum (0.4<p_{T}<3  GeV/c) direct-photon yields from Au+Au collisions at sqrt[s_{NN}]=39 and 62.4 GeV. For both beam energies the direct-photon yields are substantially enhanced with respect to expectations from prompt processes, similar to the yields observed in Au+Au collisions at sqrt[s_{NN}]=200. Analyzing the photon yield as a function of the experimental observable dN_{ch}/dη reveals that the low-momentum (>1  GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5  GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Appendectomy for Therapy-Refractory Ulcerative Colitis Results in Pathological Improvement of Colonic Inflammation: Short-Term Results of the PASSION Study

BACKGROUND AND AIMS

The objective of this study was to examine the modulating effect of an appendectomy on the disease course of therapy-refractory ulcerative colitis [UC] patients, and to analyse appendiceal pathological characteristics predictive of pathological response.

METHODS

Patients with therapy-refractory UC, and referred for proctocolectomy, were invited to undergo laparoscopic appendectomy first. The primary end points were clinical response after 3 and 12 months. Secondary end points were endoscopic remission, failure, and pathologic response. Appendiceal specimens, and pre- and post-operative biopsies were histologically graded according to the validated Geboes score.

RESULTS

Thirty patients [53% male] with a median age of 40 (interquartile range [IQR], 33-47) underwent appendectomy, with a median preoperative total Mayo score of 9 [IQR, 8-11]. After 12 months, 9 patients [30%] had lasting clinical response, of whom 5 [17%] were in endoscopic remission. Pathological evaluation was possible in 28 patients. After a median of 13.0 weeks [range 7-51], pathological response was seen in 13 patients [46%], with a median decrease of 2 points [range 1-3]. Appendiceal inflammation was highly predictive of pathological response when compared with no inflammation or extensive ulcerations [85% vs 20%, p = 0.001].

CONCLUSIONS

Appendectomy was effective in one-third of therapy-refractory UC patients, with a substantial proportion of patients demonstrating complete endoscopic remission after 1 year. Pathological response was seen in almost 50% of patients and was related to active inflammation in the appendix, limited disease, and shorter disease duration. These early results suggest that there is a UC patient group that may benefit from appendectomy.

Disturbed glutathione antioxidative defense is associated with structural brain changes in neuroleptic-naïve first-episode psychosis patients

BACKGROUND

Oxidative stress and impaired antioxidant defense are reported in schizophrenia and are thought to be associated with disturbed neurodevelopment, brain structural alterations, glutamatergic imbalance, negative symptomatology, and cognitive impairment. To test some of these assumptions we investigated the glutathione (GSH) antioxidant defense system (AODS) and brain structural abnormalities in drug-naïve individuals with first acute episode of psychosis (FEP).

METHOD

The study involved 27 drug-naïve FEP patients and 31 healthy controls (HC). GSH AODS markers and TBARS (thiobarbituric acid reactive substances) were measured in blood plasma and erythrocytes. High-resolution T₁-weighted 3T MRI were acquired from all subjects. To investigate brain structural abnormalities and effects of illness on interactions between GSH metabolites or enzyme activities and local grey matter density, voxel-based morphometry (VBM) with the computational anatomy toolbox (CAT12) was used. Symptomatology was assessed using the Positive and Negative Syndrome Scale (PANSS) and the Symptom Checklist 1990 revised (SCL-90-R).

RESULTS

(i) In FEP patients, glutathione reductase activity (GSR) was lower than in the HC group. GSR activity in plasma was inversely correlated with SCL-90-R scores of depression and PANSS scores of the negative symptom subscale. (ii) A reduction of GM was observed in left inferior frontal, bilateral temporal, as well as parietal cortices of FEP patients. (iii) Interaction analyses revealed an influence of illness on GSR/GM associations in the left orbitofrontal cortex (BA 47).

CONCLUSION

Our findings support the notion of altered GSH antioxidative defense in untreated acute psychosis as a potential pathomechanism for localized brain structural abnormalities. This pathology relates to a key brain region of social cognition, affective motivation control and decision making, and is clinically accompanied by depressive and negative symptoms.

Centrality-Dependent Modification of Jet-Production Rates in Deuteron-Gold Collisions at √[s(NN)]=200 GeV

Jet production rates are measured in p+p and d+Au collisions at sqrt[s_{NN}]=200  GeV recorded in 2008 with the PHENIX detector at the Relativistic Heavy Ion Collider. Jets are reconstructed using the R=0.3 anti-k_{t} algorithm from energy deposits in the electromagnetic calorimeter and charged tracks in multiwire proportional chambers, and the jet transverse momentum (p_{T}) spectra are corrected for the detector response. Spectra are reported for jets with 12<p_{T}<50  GeV/c, within a pseudorapidity acceptance of |η|<0.3. The nuclear-modification factor (R_{dAu}) values for 0%-100% d+Au events are found to be consistent with unity, constraining the role of initial state effects on jet production. However, the centrality-selected R_{dAu} values and central-to-peripheral ratios (R_{CP}) show large, p_{T}-dependent deviations from unity, challenging the conventional models that relate hard-process rates and soft-particle production in collisions involving nuclei.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d+Au Collisions at sqrt[s_{NN}]=200 GeV

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and minimum bias p+p collisions at sqrt[s_{NN}]=200 GeV. The charged hadron is measured at midrapidity |η|<0.35, and the energy is measured at large rapidity (-3.7<η<-3.1, Au-going direction). An enhanced near-side angular correlation across |Δη|>2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v_{2} for inclusive charged hadrons at midrapidity up to p_{T}=4.5 GeV/c. We also present the measurement of v_{2} for identified π^{±} and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at sqrt[s_{NN}]=5.02 TeV. The magnitude of the mass ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.

Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d + Au collisions at √sNN = 200 GeV

The PHENIX experiment has measured open heavy-flavor production via semileptonic decay over the transverse momentum range 1 < p(T) < 6  GeV/c at forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p + p collisions at √sNN = 200  GeV. In central d+Au collisions, relative to the yield in p + p collisions scaled by the number of binary nucleon-nucleon collisions, a suppression is observed at forward rapidity (in the d-going direction) and an enhancement at backward rapidity (in the Au-going direction). Predictions using nuclear-modified-parton-distribution functions, even with additional nuclear-p(T) broadening, cannot simultaneously reproduce the data at both rapidity ranges, which implies that these models are incomplete and suggests the possible importance of final-state interactions in the asymmetric d + Au collision system. These results can be used to probe cold-nuclear-matter effects, which may significantly affect heavy-quark production, in addition to helping constrain the magnitude of charmonia-breakup effects in nuclear matter.

Azimuthal-angle dependence of charged-pion-interferometry measurements with respect to second- and third-order event planes in Au+Au collisions at √[S(NN)]=200 GeV

Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrt[s_{NN}]=200  GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

Review article: the psychosexual impact of inflammatory bowel disease in male patients

BACKGROUND

Knowledge of the extent and the impact of sexual dysfunction and interpersonal relationships in men with inflammatory bowel disease is scarce.

AIMS

The aim of this review article was to summarise the current literature on sexual function in male patients with IBD and to provide a critical review of the IBD-related medical, surgical and psychological complications that can result in impaired quality of sexual health.

METHODS

To collect relevant articles, PubMed/Medline and Embase searches were performed using Boolean search phrases.

RESULTS

Reported rates of sexual dysfunction in male IBD patients range from 10% to 50%. Thirty-three to fifty per cent of patients report that sexual desire and satisfaction deteriorated after IBD diagnosis. Of those patients who were sexually inactive, half of these attributed lack of intercourse to underlying IBD. A striking finding reproduced in numerous studies is that disease activity relates strongly to impaired psychological function, and the most consistently reported risk factor for sexual problems in IBD patients is co-existing mood disorders. Hypogonadism is a complication of IBD and its therapies, the role of testosterone deficiency should be further explored as a potentially treatable and reversible factor in sexual dysfunction.

CONCLUSIONS

By understanding what factors contribute to poor sexual functioning in our patients, we can strive to minimise adverse psychosocial events. Further insight into this complex relationship requires an IBD-specific measure of sexual function in male patients. We recommend screening for and treating co-morbid depression, testosterone deficiency and striving for clinical remission to prevent psychosexual dysfunction in male patients with inflammatory bowel disease.

Quadrupole anisotropy in dihadron azimuthal correlations in central d+Au collisions at √(s(NN))=200 GeV

The PHENIX collaboration at the Relativistic Heavy Ion Collider (RHIC) reports measurements of azimuthal dihadron correlations near midrapidity in d+Au collisions at √(s(NN))=200 GeV. These measurements complement recent analyses by experiments at the Large Hadron Collider (LHC) involving central p+Pb collisions at √(s(NN))=5.02 TeV, which have indicated strong anisotropic long-range correlations in angular distributions of hadron pairs. The origin of these anisotropies is currently unknown. Various competing explanations include parton saturation and hydrodynamic flow. We observe qualitatively similar, but larger, anisotropies in d+Au collisions at RHIC compared to those seen in p+Pb collisions at the LHC. The larger extracted v2 values in d+Au are consistent with expectations from hydrodynamic calculations owing to the larger expected initial-state eccentricity compared with that from p+Pb collisions. When both are divided by an estimate of the initial-state eccentricity the scaled anisotropies follow a common trend with multiplicity that may extend to heavy ion data at RHIC and the LHC, where the anisotropies are widely thought to arise from hydrodynamic flow.

Nuclear modification of ψ', χc, and J/ψ production in d+Au collisions at sqrt[s(NN)]=200 GeV

We present results for three charmonia states (ψ', χc, and J/ψ) in d+Au collisions at |y|<0.35 and sqrt[s(NN)]=200  GeV. We find that the modification of the ψ' yield relative to that of the J/ψ scales approximately with charged particle multiplicity at midrapidity across p+A, d+Au, and A+A results from the Super Proton Synchrotron and the Relativistic Heavy Ion Collider. In large-impact-parameter collisions we observe a similar suppression for the ψ' and J/ψ, while in small-impact-parameter collisions the more weakly bound ψ' is more strongly suppressed. Owing to the short time spent traversing the Au nucleus, the larger ψ' suppression in central events is not explained by an increase of the nuclear absorption owing to meson formation time effects.

Medium modification of jet fragmentation in Au+Au collisions at √[s(NN)]=200 GeV measured in direct photon-hadron correlations

The jet fragmentation function is measured with direct photon-hadron correlations in p+p and Au+Au collisions at √[s(NN)]=200 GeV. The p(T) of the photon is an excellent approximation to the initial p(T) of the jet and the ratio z(T)=p(T)(h)/p(T)(γ) is used as a proxy for the jet fragmentation function. A statistical subtraction is used to extract the direct photon-hadron yields in Au+Au collisions while a photon isolation cut is applied in p+p. I(AA), the ratio of hadron yield opposite the photon in Au+Au to that in p+p, indicates modification of the jet fragmentation function. Suppression, most likely due to energy loss in the medium, is seen at high z(T). The associated hadron yield at low z(T) is enhanced at large angles. Such a trend is expected from redistribution of the lost energy into increased production of low-momentum particles.

Cold-nuclear-matter effects on heavy-quark production in d+Au collisions at sqrt[S(NN)]=200 GeV

The PHENIX experiment has measured electrons and positrons at midrapidity from the decays of hadrons containing charm and bottom quarks produced in d+Au and p+p collisions at sqrt[S(NN)]=200 GeV in the transverse-momentum range 0.85 ≤ p(T)(e) ≤ 8.5 GeV/c. In central d+Au collisions, the nuclear modification factor R(dA) at 1.5<p(T)<5 GeV/c displays evidence of enhancement of these electrons, relative to those produced in p+p collisions, and shows that the mass-dependent Cronin enhancement observed at the Relativistic Heavy Ion Collider extends to the heavy D meson family. A comparison with the neutral-pion data suggests that the difference in cold-nuclear-matter effects on light- and heavy-flavor mesons could contribute to the observed differences between the π(0) and heavy-flavor-electron nuclear modification factors R(AA).

The neural substrate of the ideomotor principle revisited: evidence for asymmetries in action-effect learning

Ideomotor theory holds that the perception or anticipatory imagination of action effects activates motor tendencies toward the action that is known to produce these effects, herein referred to as ideomotor response activation (IRA). IRA presupposes that the agent has previously learned which action produces which effects, and that this learning process has created bidirectional associations between the sensory effect codes and the motor codes producing the sensory effects. Here, we refer to this process as ideomotor learning. In the presented fMRI study, we adopted a standard two-phase ideomotor learning paradigm; a mixed between/within-subjects design allowed us to assess the neural substrate of both, IRA and ideomotor learning. We replicated earlier findings of a hand asymmetry in ideomotor processing with significantly stronger IRA by left-hand than right-hand action effects. Crucially, we traced this effect back to more pronounced associative learning for action-contingent effects of the left hand compared with effects of the right hand. In this context, our findings point to the caudate nucleus and the angular gyrus as central structures of the neural network underlying ideomotor learning.

Force-induced diffusion in microrheology

We investigate the force-induced diffusive motion of a tracer particle inside a glass-forming suspension when a strong external force is applied to the probe (active nonlinear microrheology). A schematic model of mode-coupling theory introduced recently is extended to describe the transient dynamics of the probe particle, and used to analyze recent molecular-dynamics simulation data. The model describes non-trivial transient displacements of the probe before a steady-state velocity is reached. The external force also induces diffusive motion in the direction perpendicular to its axis. We address the relation between the transverse diffusion coefficient D(perpendicular) and the force-dependent nonlinear friction coefficient ζ. Non-diffusive fluctuations in the direction of the force are seen at long times in the MD simulation, while the model describes cross-over to long-time diffusion.

Evolution of π(0) suppression in Au+Au collisions from √(s(NN))=39 to 200 GeV

Neutral-pion π(0) spectra were measured at midrapidity (|y|<0.35) in Au+Au collisions at √(s(NN))=39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1<p(T)<10 GeV/c. The high-p(T) tail is well described by a power law in all cases, and the powers decrease significantly with decreasing center-of-mass energy. The change of powers is very similar to that observed in the corresponding spectra for p+p collisions. The nuclear modification factors (R(AA)) show significant suppression, with a distinct energy, centrality, and p(T) dependence. Above p(T)=7 GeV/c, R(AA) is similar for √(s(NN))=62.4 and 200 GeV at all centralities. Perturbative-quantum-chromodynamics calculations that describe R(AA) well at 200 GeV fail to describe the 39 GeV data, raising the possibility that, for the same p(T) region, the relative importance of initial-state effects and soft processes increases at lower energies. The p(T) range where π(0) spectra in central Au+Au collisions have the same power as in p+p collisions is ≈5 and 7 GeV/c for √(s(NN))=200 and 62.4 GeV, respectively. For the √(s(NN))=39 GeV data, it is not clear whether such a region is reached, and the x(T) dependence of the x(T)-scaling power-law exponent is very different from that observed in the √(s(NN))=62 and 200 GeV data, providing further evidence that initial-state effects and soft processes mask the in-medium suppression of hard-scattered partons to higher p(T) as the collision energy decreases.

Measurement of direct photons in Au+Au collisions at √(s(NN))=200 GeV

We report the measurement of direct photons at midrapidity in Au+Au collisions at √(s(NN))=200 GeV. The direct photon signal was extracted for the transverse momentum range of 4 GeV/c<p(T)<22 GeV/c, using a statistical method to subtract decay photons from the inclusive photon sample. The direct photon nuclear modification factor R(AA) was calculated as a function of p(T) for different Au+Au collision centralities using the measured p+p direct photon spectrum and compared to theoretical predictions. R(AA) was found to be consistent with unity for all centralities over the entire measured p(T) range. Theoretical models that account for modifications of initial direct photon production due to modified parton distribution functions in Au and the different isospin composition of the nuclei predict a modest change of R(AA) from unity. They are consistent with the data. Models with compensating effects of the quark-gluon plasma on high-energy photons, such as suppression of jet-fragmentation photons and induced-photon bremsstrahlung from partons traversing the medium, are also consistent with this measurement.

Observation of direct-photon collective flow in Au + Au collisions at √s(NN)] = 200 GeV

The second Fourier component v(2) of the azimuthal anisotropy with respect to the reaction plane is measured for direct photons at midrapidity and transverse momentum (p(T)) of 1-12 GeV/c in Au + Au collisions at √s(NN)] = 200 GeV. Previous measurements of this quantity for hadrons with p(T) < 6 GeV/c indicate that the medium behaves like a nearly perfect fluid, while for p(T) > 6 GeV/c a reduced anisotropy is interpreted in terms of a path-length dependence for parton energy loss. In this measurement with the PHENIX detector at the Relativistic Heavy Ion Collider we find that for p(T) > 4 GeV/c the anisotropy for direct photons is consistent with zero, which is as expected if the dominant source of direct photons is initial hard scattering. However, in the p(T) < 4 GeV/c region dominated by thermal photons, we find a substantial direct-photon v(2) comparable to that of hadrons, whereas model calculations for thermal photons in this kinematic region underpredict the observed v(2).

WE-E-211-01: Medical Physics in Federal and State Governments

In 2010, FDA's Center for Devices and Radiological Health (CDRH) launched an "Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging" and held a public meeting on "Device Improvements to Reduce Unnecessary Radiation Exposure from Medical Imaging" March 30- 31, 2010). In follow-up, FDA is pursuing efforts using its regulatory authority as it applies to imaging equipment and manufacturers and also partnering with professional organizations such as AAPM, industry and other governmental agencies to incorporate radiation protection principles into facility quality assurance, personnel credentialing, and training requirements.The current U.S. Federal guidance on medical x-rays was published in 1976 and addresses film imaging for radiographie and dental modalities. The Medical Workgroup of the Interagency Steering Committee on Radiation Standards (ISCORS) has modernized that document to address both diagnostic and interventional approaches, film and digital imaging, and the broad range of modalities that include radiography, computed tomography, interventional fluoroscopy, dentistry, bone densitometry, and veterinary practice. The current scope and status of the document will be presented.The Military Health System is committed to providing state-of- the-art care to its beneficiaries; both at home and abroad. Personnel constraints and the continuing wars oversees have created obstacles to this objective. In the past decade, tremendous advances have occurred in Electronic Health Records (EHR) and Teleradiology. Military Radiology seeks to leverage these advances as a means of surmounting many of the challenges it faces. In this talk, the current status of DoD teleradiology and EHR will be presented.

LEARNING OBJECTIVES

1. To provide a venue in which physicists working in the public sector can interface and discuss specific issues related to supporting the federal and state governments 2. To provide a venue for medical physicists to voice specific concerns with federal/state programs where medical physics should be involved in and/or more effective. 3. To educate audience on federal or state new or updated guidelines.

Overtreatment of sigmoid diverticulitis: plea for a less aggressive approach

A less invasive approach to the treatment of left-sided colonic diverticulitis has emerged in the last decade. The standard of care for perforated or complicated diverticulitis evolved from a Hartmann's procedure, to resection and primary anastomosis, to treatment with antibiotics and percutaneous drainage in a carefully selected (Hinchey grade 2) patient subset. Recently, laparoscopic lavage emerged as a promising less invasive treatment for selected cases of Hinchey 3 patients. Likewise, for nonperforated or uncomplicated diverticulitis the approach is becoming less aggressive with a change from intravenous antimicrobial therapy, starvation and admission, to oral antibiotics and finally to observation and outpatient treatment. This less invasive or aggressive approach is due to expanding evidence on optimal treatment and is congruent with an increasing understanding that diverticulitis comprises different disease entities with heterogeneity between patients. The disease should be targeted by specific approaches, after a meticulous assessment of the diverticulitis stage, and tailored to an individual basis. Avoidance of overtreatment has obvious benefits: less in-hospital treatment, cost reduction, diminished development of antimicrobial resistance, reduction in complication rate and side effects and presumably a better quality of life for the patient. In conclusion, one might say we have overtreated the majority of diverticulitis patients for decades. More research is needed to explain the pathogenesis and multifactorial etiology and in the near future hopefully several unanswered questions regarding the optimal management of patients with different stages of diverticulitis will be answered by various ongoing trials.

Active nonlinear microrheology in a glass-forming Yukawa fluid

A molecular dynamics computer simulation of a glass-forming Yukawa mixture is used to study the anisotropic dynamics of a single particle pulled by a constant force. Beyond linear response, a scaling regime is found where a force-temperature superposition principle of a Peclet number holds. In the latter regime, the diffusion dynamics perpendicular to the force can be mapped on the equilibrium dynamics in terms of an effective temperature, whereas parallel to the force a superdiffusive behavior is seen in the long-time limit. This behavior is associated with a hopping motion from cage to cage and can be qualitatively understood by a simple trap model.

Measurements of higher order flow harmonics in Au+Au collisions at √s(NN)=200 GeV

Flow coefficients ν(n) for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at √s(NN)=200 GeV, are measured relative to event planes Ψ(n), determined at large rapidity. We report ν(n) as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The ν(n) are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s.

Suppression of back-to-back hadron pairs at forward rapidity in d+Au collisions at √s(NN)=200 GeV

Back-to-back hadron pair yields in d+Au and p+p collisions at √s(NN)=200 GeV were measured with the PHENIX detector at the Relativistic Heavy Ion Collider. Rapidity separated hadron pairs were detected with the trigger hadron at pseudorapidity |η|<0.35 and the associated hadron at forward rapidity (deuteron direction, 3.0<η<3.8). Pairs were also detected with both hadrons measured at forward rapidity; in this case, the yield of back-to-back hadron pairs in d+Au collisions with small impact parameters is observed to be suppressed by a factor of 10 relative to p+p collisions. The kinematics of these pairs is expected to probe partons in the Au nucleus with a low fraction x of the nucleon momenta, where the gluon densities rise sharply. The observed suppression as a function of nuclear thickness, p(T), and η points to cold nuclear matter effects arising at high parton densities.

Cold nuclear matter effects on J/ψ yields as a function of rapidity and nuclear geometry in d+A collisions at sqrt[s(NN)]=200 GeV

We present measurements of J/ψ yields in d+Au collisions at sqrt[s(NN)]=200  GeV recorded by the PHENIX experiment and compare them with yields in p+p collisions at the same energy per nucleon-nucleon collision. The measurements cover a large kinematic range in J/ψ rapidity (-2.2<y<2.4) with high statistical precision and are compared with two theoretical models: one with nuclear shadowing combined with final state breakup and one with coherent gluon saturation effects. In order to remove model dependent systematic uncertainties we also compare the data to a simple geometric model. The forward rapidity data are inconsistent with nuclear modifications that are linear or exponential in the density weighted longitudinal thickness, such as those from the final state breakup of the bound state.

Sport-specific power assessment for rock climbing

AIM

The popularity of rock climbing has resulted in a growing research base for the sport. However, at present there is a lack of sport-specific measures of performance in the field. The aim of this study was to examine the use of the powerslap test as a sport specific power measure.

METHODS

The participants in this study were categorised into four different ability groups (novice, intermediate, advanced and elite) based on self reported lead grade. Two separate experiments were conducted to determine validity and reliability. The powerslap test was conducted on a revolution board with two variations - wide and narrow grip, for both sides of the body. The test started with the climber hanging at full extension from two holds from which a pull up movement was made releasing one hand to slap a scaled score board above.

RESULTS

There was a significant relationship between powerslap scores and climbing ability (Left Wide: r=0.7, P<0.0005; right wide: r=0.69, P<0.0005; left narrow: r=0.73, P<0.0005; right narrow: r =0.72, P<0.0005). Further to this, scores on the powerslap narrow test were significantly differentiated by climber ability (LEFT: F(3,37)=15.74, P<0.0005; right: F(3,37)=12.16, P<0.0005). Limits of agreement and intra-class correlation indicated that the powerslap test is a reliable performance measure.

CONCLUSION

According to the present findings the narrow grip variation of the powerslap test is a useful sport-specific power test that is related to climbing performance.

Comparison of lactate sampling sites for rock climbing

Comparisons of capillary blood lactate concentrations pre and post climb have featured in the protocols of many rock climbing studies, with most researchers obtaining samples from the fingertip. The nature of rock climbing, however, places a comparatively high physiological loading on the foreaand fingertips. Indeed, the fingertips are continually required for gripping and this makes pre-climb sampling at this site problematic. The purpose of our study was to examine differences in capillary blood lactate concentrations from samples taken at the fingertip and first (big) toe in a rock climbing context. 10 participants (9 males and 1 female) completed climbing bouts at 3 different angles (91°, 100° and 110°). Capillary blood samples were taken simultaneously from the fingertip and first toe pre and post climb. A limit of agreement plot revealed all data points to be well within the upper and lower bounds of the 95% population confidence interval. Subsequent regression analysis revealed a strong relationship (R (2)=0.94, y=0.940x + 0.208) between fingertip and first toe capillary blood lactate concentrations. Findings from our study suggest that the toe offers a valid alternative site for capillary blood lactate concentration analysis in a rock climbing context.

Cross section and parity-violating spin asymmetries of W± boson production in polarized p + p collisions at sqrt[s] = 500 GeV

Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = -0.86(-0.14) (+0.30) and A(L)(e-) = 0.88(-0.71) (+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p+p collisions at a center-of-mass energy of sqrt[s] = 500 GeV with the PHENIX detector at RHIC. These e± come mainly from the decay of W± and Z0 bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W± to the light quarks. The observed electron and positron yields were used to estimate W± boson production cross sections for the e± channels of σ(pp → W+ X) × BR(W+ → e+ ν(e)) = 144.1 ± 21.2(stat)(-10.3) (+3.4) (syst) ± 21.6(norm)  pb, and σ(pp → W- X) × BR(W- → e- ν[over ¯](e)) = 31.7 ± 12.1(stat)(-8.2) (+10.1) (syst) ± 4.8(norm)  pb.