Thermally Induced Losses in Ultra-Cold Atoms Magnetically Trapped Near Room-Temperature Surfaces

We have measured magnetic trap lifetimes of ultra-cold Rb87 atoms at distances of 5-1000 microns from surfaces of conducting metals with varying resistivity. Good agreement is found with a theoretical model for losses arising from near-field magnetic thermal noise, confirming the complications associated with holding trapped atoms close to conducting surfaces. A dielectric surface (silicon) was found in contrast to be so benign that we are able to evaporatively cool atoms to a Bose-Einstein condensate by using the surface to selectively adsorb higher energy atoms.Comment: Improved theory curve eliminates discrepancy. JLTP in pres

The Mystery of the Ramsey Fringe that Didn't Chirp

We use precision microwave spectroscopy of magnetically trapped, ultra-cold 87Rb to characterize intra- and inter-state density correlations. The cold collision shifts for both normal and condensed clouds are measured. The results verify the presence of the sometimes controversial "factors of two", in normal-cloud mean-field energies, both within a particular state and between two distinct spin species. One might expect that as two spin species decohere, the inter-state factor of two would revert to unity, but the associated frequency chirp one naively expects from such a trend is not observed in our data.Comment: Proceedings of the 18th International Conference on Atomic Physics (ICAP 2002

Decoherence-driven Cooling of a Degenerate Spinor Bose Gas

We investigate the relationship between the coherence of a partially Bose-condensed spinor gas and its temperature. We observe cooling of the normal component driven by decoherence as well the effect of temperature on decoherence rates.Comment: 4 pages, 2 figure

Schooling for violence and peace : how does peace education differ from ‘normal’ schooling?

This article reviews literature on the roles of schooling in both reproducing and actively perpetrating violence, and sets out an historical explanation of why schools are socially constructed in such a way as to make these roles possible. It then discusses notions of peace education in relation to one particular project in England before using empirical data from research on the project to examine contrasts between peace education approaches and ‘normal’ schooling from the viewpoints of project workers, pupils and teachers. It concludes that such contrasts and tensions do indeed exist and that this raises serious questions about the compatibility of peace education and formal schooling

Theory of the Ramsey spectroscopy and anomalous segregation in ultra-cold rubidium

The recent anomalous segregation experiment of Lewandowski et al. (PRL, 88, 070403, 2002) shows dramatic, rapid internal state segregation for two hyperfine levels of rubidium. We simulate an effective one dimensional model of the system for experimental parameters and find reasonable agreement with the data. The Ramsey frequency is found to be insensitive to the decoherence of the superposition, and is only equivalent to the interaction energy shift for a pure superposition. A Quantum Boltzmann equation describing collisions is derived using Quantum Kinetic Theory, taking into account the different scattering lengths of the internal states. As spin-wave experiments are likely to be attempted at lower temperatures we examine the effect of degeneracy on decoherence by considering the recent experiment of Lewandowski et al. where degeneracy is around 10%. We also find that the segregation effect is only possible when transport terms are included in the equations of motion, and that the interactions only directly alter the momentum distributions of the states. The segregation or spin wave effect is thus entirely due to coherent atomic motion as foreseen in the experimental reportComment: 26 pages, 4 figures, to be published in J. Phys.

Alkali Adsorbate Polarization on Conducting and Insulating Surfaces Probed with Bose-Einstein Condensates

A magnetically trapped 87Rb Bose-Einstein condensate is used as a sensitive probe of short-range electrical forces. In particular, the electric polarization of, and the subsequent electric field generated by, 87Rb adsorbates on conducting and insulating surfaces is measured by characterizing perturbations to the magnetic trapping potential using high quality factor condensate excitations. The nature of the alterations to the electrical properties of Rb adsorbates is studied on titanium (metal) and silicon (semiconductor) surfaces, which exhibit nearly identical properties, and on glass (insulator), which displays a smaller transitory electrical effect. The limits of this technique in detecting electrical fields and ramifications for measurements of short-range forces near surfaces are discussed

Spectroscopic insensitivity to cold collisions in a two-state mixture of fermions

We have experimentally demonstrated the absence of spectroscopic resonance shifts in a mixture of two interacting Fermi gases. This result is linked to observations in an ultracold gas of thermal bosons. There, the measured resonance shift due to interstate collisions is independent of the coherence in the system, and twice that expected from the equilibrium energy splitting between the two states in a fully decohered cloud. We give a simple theoretical explanation of these observations, which elucidates the effect of coherent radiation on an incoherent mixture of atoms

Effect of Cold Collisions on Spin Coherence and Resonance Shifts in a Magnetically Trapped Ultra-Cold Gas

We have performed precision microwave spectroscopy on ultracold 87Rbconfined in a magnetic trap, both above and below the Bose-condensation transition. The cold collision frequency shifts for both normal and condensed clouds were measured, which allowed the intrastate and interstate density correlations (characterized by sometimes controversial “factors of 2”) to be determined. Additionally, temporal coherence of the normal cloud was studied, and the importance of mean-field and velocity-changing collisions in preserving coherence is discussed

HARBER ET AL. DIRECTIVE AND NONDIRECTIVE SOCIAL SUPPORT DIRECTIVE SUPPORT, NONDIRECTIVE SUPPORT, AND MORALE

The concept of social support as being directive or nondirective may help explain why helping can either boost or impede morale. The Inventory of Nondirective and Directive Instrumental Support (INDIS) was developed to investigate this question. The directive factor concerns others' attempts to dominate coping and the nondirective factor concerns others' attempts to facilitate but not dominate coping. Studies 1 and 2 identified and confirmed these factors. Study 3 showed predicted associations between INDIS subscales and measures of morale. Nondirective support (from a family member) was positively related to hope and optimism, and directive support (from either a family member or a friend) was positively related to depression and loneliness, even after controlling for other social support measures. Maintaining hope and morale is one of the most important and difficult challenges faced by people coping with serious problems. Events such as loss of loved ones, professional or interpersonal failure, and cata- 691 Journal of Social and Clinical Psychology, Vol. 24, No. 5, 2005, pp. 691-722 Kent D. Harber, Department of Psychology, Rutgers University at Newark; Joanne Kraenzle Schneider, Department of Nursing, St. Louis University; Kelly Everard and Edwin Fisher, Division of Health Behavior Research, Departments of Medicine and Pediatrics, Washington University School of Medicine. We thank Gabrielle Highstein, Ian Brissette, Lee Jussim, Bäerbel Knauper, and Annette La Greca for their contributions to this research. We also thank Alan Lambert for his assistance. Correspondence concerning this article should be addressed to Kent D. Harber, Department of Psychology, Rutgers University, Smith Hall, 101 Warren Street, Newark, NJ 07044; E-mail: [email protected]. strophic damage to oneself or to one's prized possessions can shake victims' confidence in their self worth and self-efficacy However, support is not always nurturing. In many cases social ties can fail to buttress morale, and can even exacerbate the psychological challenge of coping. Research into "negative social support" identifies a number of ways in which helping attempts can be unhelpful. Sometimes would-be supporters aggravate recovery by being critical, antagonistic, disruptive or even exploitative One of the most common forms of failed support is not generally attributable to insufficient caring, knowledge, or skills. Instead, this form of counterproductive helping is most often and most potently delivered by those closest to copers, and by those most heavily invested in their recovery. Referred to as "over-involvement" By taking charge of too much, supporters may communicate through their very acts of support that copers lack the skills or strengths needed to remedy their own problems 692 HARBER ET AL. teem However, despite these operational difficulties, advances in social support research buttress the over-involvement framework. Cutrona, To a certain degree this tension is an inescapable dilemma of support provision. However, underlying and perhaps aggravating the copers' conflicting needs for help and for autonomy may be helpers' conflicting motives to step in and step back. These motives can be characterized by the degree to which helping is nondirective or directive. In essence, what distinguishes nondirective from directive help is whether supporters attempt to advance the coper's own recuperative agenda or instead impose an agenda of recovery upon the coper. Supporters provide nondirective support when they cooperate without assuming primary responsibility for the other person's performance. Supporters provide directive support when they assume, or attempt to assume, primary responsibility for coping DIRECTIVE AND NONDIRECTIVE SOCIAL SUPPORT 693 nondirective or directive, depending on the manner in which helpers supply it. For example, a supporter who screens phone calls based on the coper's instructions would be providing nondirective support, but would be supplying directive support by screening calls either without, or against, the coper's instruction. The former advances the copers' intent, while the latter supercedes it. It is important to emphasize that nondirective and directive support do not necessarily differ in the degree to which they meet the immediate objective needs of the coper. Screening phone calls may ultimately prove helpful or unhelpful, regardless of whether this action has been requested or not. Instead, nondirective and directive helping differ in the kinds of meta-messages they communicate to copers regarding their physical, mental, and emotional competencies. These messages, we believe, can profoundly affect copers' morale regarding their coping efforts. NONDIRECTIVE SUPPORT VS. DIRECTIVE SUPPORT AND MORALE Kurt Lewin defined morale as the ability to set valued goals combined with confidence in one's own ability to achieve those goals 1 More recently, Charles Snyder and colleagues used this same prescription to define and measure hope. In much the same way as Lewin characterized morale, Snyder et al. define hope as consisting of both an ability to set goals and confidence in one's own capacity to achieve them. Hope serves "as a means of maintaining a fighting spirit" in the face of adversity (Snyder et al., 1998, p. 195). Snyder and his colleagues have demonstrated the contribution of hope to realizing important personal goals The themes of planning, agency, and control that are integral to morale are centrally implicated in the distinction between nondirective and directive support. People who receive primarily nondirective support are encouraged to identify and articulate the goals of their own recovery and, through the assistance of their supporters, to achieve the goals that they, themselves, have set. Moreover, by controlling the amount, nature, 694 HARBER ET AL. 1. Lewin explicitly associated morale with social support, stating "group 'belongingness' may increase a feeling of security, thereby raising the morale . . . of the individual" (Lewin, 1948, p. 85). and timing of help, recipients of nondirective support may be better able to both ascertain and exercise their own coping abilities. Because nondirective support allows them to assert greater agency in their own recovery, copers who mainly receive this kind of support-at least for generally tractable problems-should experience greater morale, compared to people who receive primarily directive support, where others prescribe the nature, time-course, and degree of helping. Research conducted by our group generally confirms these hypotheses DEVELOPMENT OF A SELF REPORT MEASURE OF NONDIRECTIVE AND DIRECTIVE SUPPORT The distinction between nondirective and directive support may help differentiate the ways that over-involved helping depletes morale. According to over-involvement researchers, help that over-reaches can convey to copers a lack of faith in their capacity to solve their own problems The nondirective/directive distinction has two other important advantages over "over-involvement." First, over-involvement is largely empirically derived and for this reason definitions of it vary across the studies in which it has been observed DIRECTIVE AND NONDIRECTIVE SOCIAL SUPPORT 695 ence, judgment, or need of the recipient. Nondirective support and directive support are defined a priori. They remain conceptually consistent across support situations and can be assessed independent of the recipients' preferences or situation. Second, nondirective support and directive support are not necessarily evaluative terms. Indeed there may be situations in which an emphasis on one or the other might be especially appropriate (a point we elaborate upon in the Discussion). "Over-involvement" (and "over-protectiveness"), on the other hand, carries pejorative connotations that may obscure the necessary relation between, for example, assertive helping and acute crises (see HARBER ET AL. 2. Indeed, there may be cases where directive and nondirective support are supplied invisibly, perhaps making the former less injurious and the latter less beneficial to esteem. 3. The adjective "Instrumental" emphasizes the more tangible and action-oriented kinds of support as reported in the over-involvement literature. SPECIFYING SUPPORT SOURCE Many extant measures of social support inquire about the overall quality of support people receive from their social networks. However, there is an increasing appreciation that support does not come from an undifferentiated social field. Instead, the nature and impact of support are strongly affected by support source, such as family versus friends The research reported here describes three studies regarding the development of the INDIS and the testing of the nondirective/directive model. The purpose of the first study was to identify and confirm the directive and non-directive constructs. The second study was conducted to re-confirm these sub-scales. The third study used the INDIS to test whether directive support and nondirective support are differentially associated with morale. STUDY 1 METHOD PARTICIPANTS The participants in this study were 353 Washington University undergraduates enrolled in an introductory psychology class. Two hundred thirteen (60.3%) were women and 140 (39.7%) were men. Participants' ages ranged from 17 to 21 (M = 18.5, SD = 0.92). The sample, in order of representation, was comprised of 250 non-Hispanic whites (70.8%), 73 Asians (20.7%), 18 African Americans (5.1%), and two Latinos (0.6%). Ten participants (2.8%) did not indicate their ethnicity. The religious composition of the sample included 100 Protestants (28.3%), 93 Jews (26.3%), 73 Catholics (20.7%), and 44 atheist or agnostic (12.5%). Forty-three participants (12.2%) did not indicate their religious affiliation. Participants completed the questionnaire as part of a class exercise. DIRECTIVE AND NONDIRECTIVE SOCIAL SUPPORT 697 MEASURES Inventory of Nondirective and Directive Instrumental Support (INDIS). A pool of 40 directive and nondirective items, emphasizing instrumental support, was generated for purposes of modified Q-sorting. These items were based upon themes that emerged from structured interviews investigating directive and nondirective support, and from general concepts of these kinds of support developed by Fisher and his colleagues (e.g., Fisher, Bickle et al., 1997; Fisher, La Greca et al.,1997). Seven colleagues who have conducted extensive interviews designed to investigate directive support and nondirective support were enlisted to complete the sorting task. Sixteen items were excluded due to low concordance (i.e., less than 75% agreement that they represented either directive or nondirective support). The remaining 24 items (12 directive and 12 nondirective) were subsequently administered in survey form. There were two parallel versions of the INDIS, one focusing on support from a family member and the other focusing on support from a friend. The items comprising these versions were the same; the difference between the versions was in the specific source (family member or friend) to which the items referred. Participants indicated how accurately each item reflected the kind of help that they received from their respective support source, using five-point Likert scales that ranged from 1 = not at all accurate to 5 = extremely accurate. Background Questionnaire. A brief background questionnaire was prepared that sampled participants' age, race, gender, and religion. In addition, it instructed participants to indicate whether or not they had experienced any of nine major kinds of problems including personal health, romantic relationships, non-romantic relationships, bereavement, loved one's injury or illness, personal victimization, loved one's victimization, or problems in academics, jobs, or other valued area, or any other kind of problem. Two final questions asked participants to indicate which problem was the most severe, and which family member or friend (depending on INDIS version) served as their primary source of support. PROCEDURE Participants completed the background survey first. They then completed either the family member or the friend version of the INDIS, according to random assignment. Participants completed the INDIS in the context of the most severe problem they weathered in the past 12 months, and in reference to the individual friend or family member (de- 698 HARBER ET AL. pending on INDIS version) who served as their primary support source in dealing with this particular problem. RESULTS PSYCHOMETRIC ANALYSIS OF STUDY 1 Because we had anticipated the underlying latent variable structure of the sub-scales (one directive and one nondirective latent variable), it would have been appropriate for us to immediately test the model using confirmatory factor analysis The 24 survey items were entered into principal components analyses. Because we expected to find two distinct constructs, one directive and one nondirective, two factors were rotated orthogonally using Varimax rotation. For both the family member and friend version of the INDIS items were eliminated if: (1) they did not load on either factor at or above .30; (2) they cross-loaded with a difference in loadings less than .10; or (3) they failed to load on the same factor for both the family member and friend versions. Four items were eliminated through this process. The remaining 20 items accounted for 44.2% of the family version variance and 40.6% of the friend version variance. Kaiser-Meyer-Olkin Measure of Sampling Adequacies (KMO) of .86 and .82 respectively indicated that factor analysis was appropriate for these data. As expected, two factors emerged from this analysis, for both the family and friend versions, which were respectively comprised of nondirective and directive items. The nondirective factor contained those items that reflected support in which the provider cooperated with the recipient without "taking over" responsibility or control. The directive factor contained items that reflected taking over the tasks of coping. DIRECTIVE AND NONDIRECTIVE SOCIAL SUPPORT 699 CONFIRMATORY FACTOR ANALYSIS In order to determine how well individual items fit the overall model, we proceeded to confirmatory factor analysis, using structural equation modeling to evaluate the fit indices of the remaining 20 items. Confirmatory factor analysis uses a set of measured variables (e.g., questionnaire items) to form a variance/covariance matrix from which unobservable latent variables (e.g., hypothesized factors) can be tested. The loading of each questionnaire item indicates its relationship with the latent variable (i.e., construct or factor). In confirmatory factor analysis, the measurement model specifies the observed variables that define the constructs and "reflects the extent to which the observed variables are assessing the latent variables in terms of reliability and validity" (Schumaker & Lomax, 1996, p. 64). We conducted confirmatory factor analysis to detect and delete weak questionnaire items (i.e., items that detract from overall model fit). The process is iterative; after detecting and deleting a weak item, the entire model is re-analyzed in order to detect and delete additional weak items, the model is analyzed again, and so forth until the model cannot be improved with additional deletions guidelines as aids for interpretation and not as absolute thresholds. We reported the RMSEA 90% confidence intervals as recommended by DIRECTIVE AND NONDIRECTIVE SOCIAL SUPPORT 701 STUDY 2 INTRODUCTION Study 1 provided initial confirmation of the predicted two-factor structure of the INDIS. Exploratory analyses showed that items predicted to comprise the nondirective and directive subscales did so, and confirmatory analyses demonstrated that these items generally fit the overall model. However, in order to ensure that the confirmatory results obtained in Study 1 were reliable, we conducted Study 2 to obtain a separate confirmatory test of the two-factor model. METHOD PARTICIPANTS The sample consisted of 142 undergraduates recruited from Rutgers University at Newark (74%) and from Washington University (26% PROCEDURE Participants were tested en masse in a large introductory psychology course at Rutgers, or individually at Washington University, where the study was included as an added task to other ongoing experiments. Participants first completed the revised nine-item INDIS and then filled out a brief background questionnaire sampling gender, age, and ethnic background. Data were collected anonymously. RESULTS AND DISCUSSION The nine items that comprise the INDIS (as identified in Study 1) were taken into confirmatory factor analysis using LISREL. The measurement models for the family member version and the friend version were reexamined separately. As before, items were constrained to zero on latent 702 HARBER ET AL. DIRECTIVE AND NONDIRECTIVE SOCIAL SUPPORT 703 constructs to which they did not belong and the latent constructs were allowed to correlate. Initial fit indices for the family member version (N = 142) were R 2 (26) = 123.24, p = 0.00; RMSEA = .16, 90% CI = 0.13-0.19; CFI = .88; and IFI = .88. Initial fit indices for the friend version (N = 142) were R 2 (26) = 107.40, p = 0.00; RMSEA = .15, 90%CI = 0.12-0.18; CFI = .82; and IFI = .82. Item trimming indicated that the friend model would be improved slightly by deleting the weakest item, "Knows when to back off from being helpful." However, we decided to provisionally retain this item because it fit the model in the Study 1 confirmatory analysis, it is conceptually central to the non-directive factor, and because the model demonstrated acceptable fit in Study 2 when this item was included in the friend version. We therefore decided that the final disposition of this item would be determined in confirmatory analysis conducted in Study 3. Several directive items were allowed to covary. "Decided what kind of help I needed" covaried with "Decided who could help me" and "Organized my schedule for me." "Solved problems for me" covaried with "Took charge of my problems." These items were allowed to covary based on the modification indices and supported conceptually Cumulatively, these fit indices show that the hypothesized constructs of the INDIS are supported by the data reasonably well, and that they support the findings obtained in the prior study. Coefficient alphas were satisfactory. For the family member version, alpha coefficients were .78 for Nondirective Support and .84 for Directive Support. For the friend version they were .75 for Nondirective Support and .79 for Directive Support. Consistent with the fit indices, subscale alphas also supported the strength of the measures. In sum, confirmatory analyses of the INDIS in Study 2 provided further evidence that both the family member and friend versions of the INDIS are psychometrically sound measures. Notably, this reconfirmation was obtained even after sampling from a population largely distinct from the one sampled in the initial test of the two-factor INDIS

Spatial Resolution of Spin Waves in an Ultra-Cold Gas

We present the first spatially resolved images of spin waves in a gas. The complete longitudinal and transverse spin field as a function of time and space is reconstructed. Frequencies and damping rates for a standing-wave mode are extracted and compared with theory