Intoxicated eyewitnesses:the effect of a fully balanced placebo design on event memory and metacognitive control

Few studies have examined the impact of alcohol on metacognition for witnessed events. We used a 2x2 balanced placebo design, where mock-witnesses expected and drank alcohol, did not expect but drank alcohol, did not expect nor drank alcohol, or expected but did not drink alcohol. Participants watched a mock-crime in a bar-lab, followed by free recall and a cued-recall test with or without the option to reply ‘don’t know’ (DK). Intoxicated mock-witnesses’ free recall was less complete but not less accurate. During cued-recall, alcohol led to lower accuracy, and reverse placebo participants gave more erroneous and fewer correct responses. Permitting and clarifying DK responses was associated with fewer errors and more correct responses for sober individuals; and intoxicated witnesses were less likely to opt out of erroneous responding to unanswerable questions. Our findings highlight the practical and theoretical importance of examining pharmacological effects of alcohol and expectancies in real-life settings

Forces on Bins - The Effect of Random Friction

In this note we re-examine the classic Janssen theory for stresses in bins, including a randomness in the friction coefficient. The Janssen analysis relies on assumptions not met in practice; for this reason, we numerically solve the PDEs expressing balance of momentum in a bin, again including randomness in friction.Comment: 11 pages, LaTeX, with 9 figures encoded, gzippe

Average stresses and force fluctuations in non-cohesive granular materials

A lattice model is presented for investigating the fluctuations in static granular materials under gravitationally induced stress. The model is similar in spirit to the scalar q-model of Coppersmith et al., but ensures balance of all components of forces and torques at each site. The geometric randomness in real granular materials is modeled by choosing random variables at each site, consistent with the assumption of cohesionless grains. Configurations of the model can be generated rapidly, allowing the statistical study of relatively large systems. For a 2D system with rough walls, the model generates configurations consistent with continuum theories for the average stresses (unlike the q-model) without requiring the assumption of a constitutive relation. For a 2D system with periodic boundary conditions, the model generates single-grain force distributions similar to those obtained from the q-model with a singular distribution of q's.Comment: 18 pages, 10 figures. Uses aps,epsfig,graphicx,floats,revte

Daily bathing with chlorhexidine-based soap and the prevention of Staphylococcus aureus transmission and infection

OBJECTIVE: Determine if daily bathing with chlorhexidine-based soap decreased methicillin-resistant Staphylococcus aureus (MRSA) transmission and ICU-acquired S. aureus infection among ICU patients. DESIGN: Prospective pre-post-intervention study with control unit SETTING: 1,250 bed tertiary-care teaching hospital PATIENTS: Medical and surgical intensive care unit (ICU) patients METHODS: Active surveillance for MRSA colonization was performed in both ICUs. In June 2005, a chlorhexidine bathing protocol was implemented in the surgical ICU. Changes in S. aureus transmission and infection rate before and after implementation were analyzed using time-series methodology. RESULTS: The intervention unit had a 20.68% decrease in MRSA acquisition after institution of the bathing protocol [pre-intervention 12.64 vs. post-intervention 10.03 cases/1000 patient-days-at-risk (95% CI: −5.19 – −0.04, p = 0.046)]. There was no significant change in MRSA acquisition in the control ICU during the study period [10.97 pre-June 2005 vs. 11.33/1000 patient-days at risk post-June 2005 (95% CI −37.40 – 15.19, p = 0.40)]. There was a 20.77% decrease in all S. aureus (including MRSA) acquisition in the intervention ICU from 2002-2007 [19.73 pre-intervention to 15.63 cases per 1000 patient-days at risk post-intervention (95% CI −7.25 – −0.95, p=0.012)]. The incidence of ICU-acquired MRSA infections decreased by 41.37% in the intervention ICU (1.96 pre-intervention vs. 1.15 infections per 1000 patient-days at risk post-intervention; p=0.001). CONCLUSIONS: Institution of daily chlorhexidine bathing in an ICU resulted in a decrease in the transmission of S. aureus, including MRSA. These data support the use of routine daily chlorhexidine baths to decrease rates of S. aureus transmission and infections

A systematic review on the relationship between self-esteem and interrogative suggestibility

Some factors, such as age, learning disability and mental health difficulties, have been identified as making police suspects more vulnerable to suggestibility and false confessions during interview. However, there has been no systematic review on the association between self-esteem and suggestibility. Seven electronic bibliographic databases and reference lists of previous literature reviews of suggestibility in children were searched. Selected studies were quality assessed using pre-defined criteria before data were extracted. Electronic searches yielded 1914 hits. Of these, 685 duplicates, 1181 irrelevant references and 39 references that did not meet the inclusion criteria were removed. Nine publications were included in the review. Significant correlations between self-esteem and suggestibility, most notably on the Yield 1 subscale of the GSS, were found but four of the nine studies found no significant correlation. The prevalent use of self-report measures and lack of clarity in defining self-esteem limit the validity of those studies

Quantizing Charged Magnetic Domain Walls: Strings on a Lattice

The discovery by Tranquada et al. of an ordered phase of charged domain walls in the high-Tc cuprates leads us to consider the possible existence of a quantum domain-wall liquid. We propose minimal models for the quantization, by meandering fluctuations, of isolated charged domain walls. These correspond to lattice string models. The simplest model of this kind, a directed lattice string, can be mapped onto a quantum spin chain or on a classical two-dimensional solid-on-solid surface model. The model exhibits a rich phase diagram, containing several rough phases with low-lying excitations as well as ordered phases which are gapped.Comment: 4 two-column pages, including the 3 Postscript figure

Reentrant Melting of Soliton Lattice Phase in Bilayer Quantum Hall System

At large parallel magnetic field $B_\parallel$, the ground state of bilayer quantum Hall system forms uniform soliton lattice phase. The soliton lattice will melt due to the proliferation of unbound dislocations at certain finite temperature leading to the Kosterlitz-Thouless (KT) melting. We calculate the KT phase boundary by numerically solving the newly developed set of Bethe ansatz equations, which fully take into account the thermal fluctuations of soliton walls. We predict that within certain ranges of $B_\parallel$, the soliton lattice will melt at $T_{\rm KT}$. Interestingly enough, as temperature decreases, it melts at certain temperature lower than $T_{\rm KT}$ exhibiting the reentrant behaviour of the soliton liquid phase.Comment: 11 pages, 2 figure

Phase transitions in the antiferromagnetic XY model with a kagome lattice

The ground state of the antiferromagnetic XY model with a kagome lattice is characterized by a well developed accidental degeneracy. As a consequence the phase transition in this system consists in unbinding of pairs of fractional vortices. Addition of the next-to-nearest neighbors (NNN) interaction leads to stabilization of the long-range order in chirality (staggered chirality). We show that the phase transition, related with destruction of this long-range order, can happen as a separate phase transition below the temperature of the fractional vortex pairs unbinding only if the NNN coupling is extremely weak, and find how the temperature of this transition depends on coupling constants. We also demonstarte that the antiferromagnetic ordering of chiralities and, accordingly, the presence of the second phase transition are induced by the free energy of spin wave fluctuations even in absence of the NNN coupling.Comment: 10 pages (Revtex) + 8 figures (in 2 postscript files