Generating Multiparticle Entangled States by Self-Organization of Driven Ultracold Atoms.

We describe a mechanism for guiding the dynamical evolution of ultracold atomic motional degrees of freedom toward multiparticle entangled Dicke-squeezed states, via nonlinear self-organization under external driving. Two examples of many-body models are investigated. In the first model, the external drive is a temporally oscillating magnetic field leading to self-organization by interatomic scattering. In the second model, the drive is a pump laser leading to transverse self-organization by photon-atom scattering in a ring cavity. We numerically demonstrate the generation of multiparticle entangled states of atomic motion and discuss prospective experimental realizations of the models. For the cavity case, the calculations with adiabatically eliminated photonic sidebands show significant momentum entanglement generation can occur even in the "bad cavity" regime. The results highlight the potential for using self-organization of atomic motion in quantum technological applications.

Control of Light-Atom Solitons and Atomic Transport by Optical Vortex Beams Propagating through a Bose-Einstein Condensate.

We model propagation of far-red-detuned optical vortex beams through a Bose-Einstein condensate using nonlinear Schrödinger and Gross-Pitaevskii equations. We show the formation of coupled light-atomic solitons that rotate azimuthally before moving off tangentially, carrying angular momentum. The number, and velocity, of solitons, depends on the orbital angular momentum of the optical field. Using a Bessel-Gauss beam increases radial confinement so that solitons can rotate with fixed azimuthal velocity. Our model provides a highly controllable method of channeling a BEC and atomic transport.

Multiple Self-Organized Phases and Spatial Solitons in Cold Atoms Mediated by Optical Feedback.

We study the transverse self-structuring of cold atomic clouds with effective atomic interactions mediated by a coherent driving beam retroreflected by means of a single mirror. The resulting self-structuring due to optomechanical forces is much richer than that of an effective-Kerr medium, displaying hexagonal, stripe and honeycomb phases depending on the interaction strength parametrized by the linear susceptibility. Phase domains are described by Ginzburg-Landau amplitude equations with real coefficients. In the stripe phase the system recovers inversion symmetry. Moreover, the subcritical character of the honeycomb phase allows for light-density feedback solitons functioning as self-sustained dark atomic traps with motion controlled by phase gradients in the driving beam.

Avoided Crossing and sub-Fourier-sensitivity in Driven Quantum Systems.

The response of a linear system to an external perturbation is governed by the Fourier limit, with the inverse of the interaction time constituting a lower limit for the system bandwidth. This does not hold for nonlinear systems, which can thus exhibit sub-Fourier-behavior. The present Letter identifies a mechanism for sub-Fourier-sensitivity in driven quantum systems, which relies on avoided crossing between Floquet states. Features up to three orders of magnitude finer than the Fourier limit are presented.

Younger Dryas deglaciation of Scotland driven by warming summers.

The Younger Dryas Stadial (YDS; ∼ 12,900-11,600 y ago) in the Northern Hemisphere is classically defined by abrupt cooling and renewed glaciation during the last glacial-interglacial transition. Although this event involved a global reorganization of atmospheric and oceanic circulation [Denton GH, Alley RB, Comer GC, Broecker WS (2005) Quat Sci Rev 24:1159-1182], the magnitude, seasonality, and geographical footprint of YDS cooling remain unresolved and pose a challenge to our understanding of abrupt climate change. Here, we present a deglacial chronology from Scotland, immediately downwind of the North Atlantic Ocean, indicating that the Scottish ice cap disintegrated during the first half of the YDS. We suggest that stratification of the North Atlantic Ocean resulted in amplified seasonality that, paradoxically, stimulated a severe wintertime climate while promoting warming summers through solar heating of the mixed layer. This latter process drove deglaciation of downwind landmasses to completion well before the end of the YDS.

Recent tropical Andean glacier retreat is unprecedented in the Holocene.

Tropical glaciers have retreated over recent decades, but whether the magnitude of this retreat exceeds the bounds of Holocene fluctuations is unclear. We measured cosmogenic beryllium-10 and carbon-14 concentrations in recently exposed bedrock at the margin of four glaciers spanning the tropical Andes to reconstruct their past extents relative to today. Nuclide concentrations are near zero in almost all samples, suggesting that these locations were never exposed during the Holocene. Our data imply that many glaciers in the tropics are probably now smaller than they have been in at least 11,700 years, making the tropics the first large region where this milestone has been documented.

Magnetization transfer histograms in clinically isolated syndromes suggestive of multiple sclerosis.

In established multiple sclerosis, magnetization transfer ratio (MTR) histograms reveal abnormalities of normal-appearing white matter (NAWM) and grey matter (NAGM). The aim of this study was to investigate for such abnormalities in a large cohort of patients presenting with clinically isolated syndromes suggestive of multiple sclerosis. Magnetization transfer imaging was performed on 100 patients (67 women, 33 men, median age 32 years) a mean of 19 weeks (SD 3.8, range 12-33 weeks) after symptom onset with a clinically isolated syndrome and in 50 healthy controls (34 women, 16 men, median age 32.5 years). SPM99 software was used to generate segmented NAWM and NAGM MTR maps. The volumes of T2 lesions, white matter and grey matter were calculated. Eighty-one patients were followed up clinically and with conventional MRI after 3 years (n = 61) or until they developed multiple sclerosis if this occurred sooner (n = 20). Multiple regression analysis was used to investigate differences between patients and controls with age, gender and volume measures as covariates to control for potential confounding effects. The MTR histograms for both NAWM and NAGM showed a reduction in the mean (NAWM, 38.14 versus 38.33, P = 0.001; NAGM 32.29 versus 32.50, P = 0.009; units in pu) and peak location, with a left shift in the histogram. Mean NAWM and NAGM MTR were also reduced in the patients who developed clinically definite multiple sclerosis and multiple sclerosis according to the McDonald criteria but not in the 24 patients with normal T2-weighted brain magnetic resonance imaging (MRI). MTR abnormalities occur in the NAWM and NAGM at the earliest clinical stages of multiple sclerosis.

Cytotoxic activity, tumor accumulation, and tissue distribution of ruthenium-103-labeled bleomycin.

Bleomycin (BLM) was labeled with gamma-emitting 103Ru. Yields of 103Ru-labeled BLM as high as 50.6% were attained. 103Ru-labeled BLM was stable in vitro and the 103ru label was not displaced by large excesses of Cu (II) and Co (II) or Fe (III). Chromatography of the urine following 103Ru-labeled BLM injection indicated no in vivo decomposition. Pharmacokinetic studies in healthy inbred SD and tumor-bearing inbred BUF rats demonstrated tumor accumulations, tissue distributions, and clearance nearly identical with those reported for 3H-labeled BLM. Cytotoxicity studies on a WI-L2 human B-cell line showed that BLM labeled with nonradioactive Ru retained 100% of the activity demonstrated by native BLM. Thus BLM may be labeled with isotopes of Ru to form stable complexes by a simple, rapid reaction without loss of its chemotherapeutic properties or variations in its in vivo distribution. BLM labeled with the proper Ru isotope should prove useful as a gamma-emitting tracer for BLM or a beta-emitting compound capable of providing combination chemotherapy and radiotherapy of tumors.

The effect of certain variables on the tumor and tissue distribution of tracers V: false carrier effect, II, Fe.

The effect of Fe3+ citrate on carrier-free 67Ga and 59Fe kinetics was studied in a Buffalo rat-Morris 7777 hepatoma model. Two mg Fe3+ citrate/Kg were administered intravenously in a variety of time sequences, prior to and following the tracers, and the rats were killed at 4 or 24 hours. 67Ga concentrations could be increased in tumor and decreased in most normal tissues. Administering Fe3+ both one half hour before and 2 hours after the tracers produced 67Ga values equivalent to 72-hour carrier-free values after 4 hours, while simultaneously decreasing gut secretion and increasing urinary excretion. The 59Fe and 67Ga kinetics suggested that events at both vascular and cellular levels were responsible for these changes. This study demonstrated the potential utility of Fe3+ citrate for improving both conventional 67Ga and positron (68Ga) imaging of tumors.

Out to pasture: a case for the retirement of Canadian mental health legislation.

The emergence of new adult guardianship and related legislation and systems in British Columbia, Ontario, and other jurisdictions has generated questions about the utility of separate mental health legislation. Mental health statutes are the descendents of legislation that once created and regulated separate institutions and systems for the insane (later known as the mentally diseased and, more recently, the mentally ill). Such legislation is no longer consistent with the dominant community care and treatment strategies in the mental health field and the growing trend to recognize and respect consumer involvement in care and treatment decision making. Emerging legislation in the guardianship field makes provision for a range of options and mechanisms that can replace separate mental health statutes (e.g., general consent to health care legislation, and provision for enduring powers of attorney of the person and Ulysses agreements) and produce a new and more effective legal framework for the provision of mental health care and treatment.

Paleoindian settlement of the high-altitude Peruvian Andes.

Study of human adaptation to extreme environments is important for understanding our cultural and genetic capacity for survival. The Pucuncho Basin in the southern Peruvian Andes contains the highest-altitude Pleistocene archaeological sites yet identified in the world, about 900 meters above confidently dated contemporary sites. The Pucuncho workshop site [4355 meters above sea level (masl)] includes two fishtail projectile points, which date to about 12.8 to 11.5 thousand years ago (ka). Cuncaicha rock shelter (4480 masl) has a robust, well-preserved, and well-dated occupation sequence spanning the past 12.4 thousand years (ky), with 21 dates older than 11.5 ka. Our results demonstrate that despite cold temperatures and low-oxygen conditions, hunter-gatherers colonized extreme high-altitude Andean environments in the Terminal Pleistocene, within about 2 ky of the initial entry of humans to South America.

PP164. Magnesium sulphate for prevention and treatment of eclampsia in low and middle income countries: Systematic review of tested regimens.

INTRODUCTION: Magnesium sulphate (MgSO4) is regarded as the most effective prophylactic and therapeutic agent for eclampsia. Although well studied and widely used in high income countries (HICs), MgSO4 is under utilized in low and middle income countries (LMICs) due to many factors including lack of adequately trained health care providers, supplies for administration, or the MgSO4 itself, in addition to fear of potential adverse effects. OBJECTIVES: To systematically review the dosing and effectiveness of MgSO4 regimens administered in LMICs to women with pre-eclampsia or eclampsia. METHODS: We searched Medline, EMBASE, IPA, CINAHL, CDSR and CENTRAL databases for English language randomized controlled trials (RCT) and observational studies of MgSO4 regimens administered in LMICs to women with pre-eclampsia or eclampsia. Two authors independently reviewed search results and extracted relevant data from eligible studies. No quality assessment was performed. RESULTS: Twenty two papers (7 RCT and 15 observational studies) from 12 LMIC met our inclusion criteria, of which 21 were conducted in hospital settings. Two studied MgSO4 for eclampsia prevention ,14 for eclampsia treatment and 6 studied MgSO4 for both. In 20 studies, both loading and maintenance MgSO4 dosing was administered, with intravenous (IV) or combined IV and intramuscular (IM) loading doses of 4-15g and IV or IM maintenance doses up to 2g/h. Five studies used only the IV route of administration, while the remainder coupled IV with IM administration. All studies were effective at preventing the initiation and/or recurrence of eclamptic seizures. One study of 265 women with eclampsia found that MgSO4 loading dose administration in the community (4g IV over 20min plus 3g IM in each buttock) before referral and administration of maintenance therapy in hospital was more effective in decreasing recurrent eclampsia compared with the standard practice of referral to hospital where the initial dose of MgSO4 was administered [RR of 0.23, 95% CI 0.11, 0.49]. The two studies of 4g IV plus 10g IM loading dose-only regimens did not show a significant reduction in eclamptic seizures compared with identical loading dose plus 5g/4h IM maintenance dose regimens [RR of 1.38, 95% CI of 0.23, 8.45]. However the combined sample size was small (N=180 women). CONCLUSION: In LMICs, most studies of MgSO4 for pre-eclampsia or eclampsia were conducted in high level health care facilities and administered MgSO4 by the IV route, at least in part. The one study of community administration of a MgSO4 loading dose showed this approach to be effective. There are limited data to support loading dose-only regimens.