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.

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.

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.

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.

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.

Ten years of breast screening in the Nova Scotia Breast Screening Program, 1991-2001. experience: use of an adaptable stereotactic device in the diagnosis of screening-detected abnormalities.

OBJECTIVE: To evaluate and present 10-year outcomes of the Nova Scotia Breast Screening Program (NSBSP), a population-based screening program in the province of Nova Scotia, Canada, total population 900 000. SETTING: Organized Breast Screening Program in Nova Scotia, Canada. METHODS: Rates of participation, abnormal referrals, cancer detection rates, and benign:malignant (B:M) rates for core biopsy and surgical biopsy were calculated for asymptomatic women receiving a mammogram through the NSBSP 1991-2001. RESULTS: Of 192 454 mammograms performed on 71 317 women, 33% were aged 40 to 49 years, 39% aged 50 to 59 years, 23% aged 60 to 69 years, and 5% aged 70 years and over. Cancer detection rate increased in each age group respectively: 3.7, 5.8, 9.7, and 13.5 per 1000 population on first-time screens. The positive predictive value of an abnormal screen increased with increasing age groups. Benign breast surgery decreased with increased use of needle core breast biopsy (NCBB). Open surgery decreased from 25 to 6 surgeries per 1000 screens. Of 1519 open surgical procedures (1328 women), 878 cancers were removed, with 37% 10 mm or less, and 61% 15 mm or less. In 613 women in whom the node status was assessed, 79% were negative. CONCLUSION: A quality screening program incorporating NCBB in the diagnostic work-up is effective in the early detection of breast cancer and results in less open surgery, particularly in younger women.

Elevated white matter myo-inositol in clinically isolated syndromes suggestive of multiple sclerosis.

Normal-appearing white matter (NAWM) in established multiple sclerosis has been shown to be abnormal using a variety of magnetic resonance (MR) techniques, including proton MR spectroscopy ((1)H-MRS), although the stage at which these changes first appear is less clear. Using a 1.5 T scanner and single-voxel (1)H-MRS [TR 3000 ms, TE 30 ms, point-resolved spectroscopy (PRESS) localization], we determined NAWM metabolite concentrations in 96 patients a mean of 19 weeks (range 12-28 weeks) after onset of a clinically isolated syndrome (CIS) suggestive of multiple sclerosis and in 44 healthy control subjects. Absolute concentrations of N-acetyl-aspartate, total creatine and phosphocreatine (Cr), choline-containing compounds, glutamate plus glutamine, and myo-inositol (Ins) were estimated automatically using the LCModel. Compared with control subjects, the concentration of Ins was elevated in CIS NAWM (mean 3.31 mM, SD 0.86 versus mean 3.82 mM, SD 1.06; P = 0.001). The increase in Ins was also seen in the patient subgroup with abnormal T2-weighted MRI (mean 3.88 mM, SD 1.10; P = 0.001) and in those who satisfied the McDonald criteria for multiple sclerosis (mean 4.04 mM, SD 1.31; P = 0.001). An increase in Cr was also observed in CIS NAWM (P = 0.023), but other metabolites did not significantly differ between the whole CIS group and control subjects. There was no significant correlation between NAWM Ins and T2 lesion load. The early increase in Ins may reflect a process of pathogenic importance in multiple sclerosis NAWM. Follow-up studies will investigate whether the increase in NAWM Ins is of prognostic importance for future relapses and disability.

Team approaches to treating children with disabilities: a comparison.

OBJECTIVE: To investigate differences in team functioning between the multidisciplinary and transdisciplinary models when treating children with disabilities. DESIGN: A crossover trial. SETTING: An outpatient educational and rehabilitation program in a rehabilitation institute based at a university medical center. PARTICIPANTS: A population-based sample of 19 rehabilitation specialists and educators. INTERVENTION: Participants attended four team meetings using the multidisciplinary approach and then attended four team meetings using the transdisciplinary approach. OUTCOME MEASURES: Behavioral ratings of team participation (Transdisciplinary Team Rating Scale) and self-report instruments of team development (Team Assessment Questionnaire) and treatment planning and goal development (Staff Perception Questionnaire). RESULTS: Results of t tests confirmed the hypothesis that there was more team member participation during transdisciplinary meetings than during multidisciplinary meetings (p=.027). There were no differences in levels of team development (p=.329); however, staff members favored the transdisciplinary model for treatment planning and goal development (p < .001). CONCLUSION: This study provides evidence of the effectiveness of the transdisciplinary model. Further research is now needed to investigate outcome variables such as rate of success in attaining treatment goals when using this model.

A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean.

The seeding of an expanse of surface waters in the equatorial Pacific Ocean with low concentrations of dissolved iron triggered a massive phytoplankton bloom which consumed large quantities of carbon dioxide and nitrate that these microscopic plants cannot fully utilize under natural conditions. These and other observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.

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.

Stress, appraisal, and coping in mothers of disabled and nondisabled children.

The cognitive-behavioral model of stress and coping provided the framework for this study of mothers of physically disabled children (n = 69) and mothers of nondisabled children (n = 63). The first aim was to test for differences between groups in responses to stressful parenting events. As hypothesized, mothers of disabled children reported higher levels of depressive symptomatology. Differences in psychological distress and health status approached significance. The second aim was to explore the mediating influences of coping strategies and cognitive appraisals. As predicted, emotion-focused coping was related to increased psychological distress in mothers of disabled children whereas problem-focused coping was associated with decreased distress. Both relationships were significant even after controlling for differences in type of parenting stressor. Hierarchical regressions showed that 58 and 25% of the variance in psychological distress was explained by the independent variables; however, the predictors were different for the two groups of mothers. Factors that may explain the differential effectiveness of coping and appraisal, and clinical implications of this study are discussed.