1,522 research outputs found

    Gluon scattering in AdS at finite string coupling from localization

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    We consider gluons scattering in Type IIB string theory on AdS5 × S5/ℤ2 in the presence of D7 branes, which is dual to the flavor multiplet correlator in a certain 4d N = 2 USp(2N) gauge theory with SO(8) flavor symmetry and complexified coupling τ. We compute this holographic correlator in the large N and finite τ expansion using constraints from derivatives of the mass deformed sphere free energy, which we compute to all orders in 1/N and finite τ using supersymmetric localization. In particular, we fix the F4 higher derivative correction to gluon scattering on AdS at finite string coupling τs = τ in terms of Jacobi theta functions, which feature the expected relations between the SL(2, ℤ) duality and the SO(8) triality of the CFT, and match it to the known flat space term. We also use the flat space limit to compute D2F4 corrections of the correlator at finite τ in terms of a non-holomorphic Eisenstein series. At weak string coupling, we find that the AdS correlator takes a form which is remarkably similar to that of the flat space Veneziano amplitude

    Gluon scattering in AdS at finite string coupling from localization

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    We consider gluons scattering in Type IIB string theory on AdS5×S5/Z2_5\times S^5/\mathbb{Z}_2 in the presence of D7 branes, which is dual to the flavor multiplet correlator in a certain 4d N=2\mathcal{N}=2 USp(2N)USp(2N) gauge theory with SO(8)SO(8) flavor symmetry and complexified coupling τ\tau. We compute this holographic correlator in the large NN and finite τ\tau expansion using constraints from derivatives of the mass deformed sphere free energy, which we compute to all orders in 1/N1/N and finite τ\tau using supersymmetric localization. In particular, we fix the F4F^4 higher derivative correction to gluon scattering on AdS at finite string coupling τs=τ\tau_s=\tau in terms of Jacobi theta functions, which feature the expected relations between the SL(2,Z)SL(2,\mathbb{Z}) duality and the SO(8)SO(8) triality of the CFT, and match it to the known flat space term. We also use the flat space limit to compute D2F4D^2F^4 corrections of the correlator at finite τ\tau in terms of a non-holomorphic Eisenstein series. At weak string coupling, we find that the AdS correlator takes a form which is remarkably similar to that of the flat space Veneziano amplitude.Comment: 24 pages plus appendice

    Carrier-induced ferromagnetism in n-type ZnMnAlO and ZnCoAlO thin films at room temperature

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    The realization of semiconductors that are ferromagnetic above room temperature will potentially lead to a new generation of spintronic devices with revolutionary electrical and optical properties. Transition temperatures in doped ZnO are high but, particularly for Mn doping, the reported moments have been small. We show that by careful control of both oxygen deficiency and aluminium doping the ferromagnetic moments measured at room temperature in n-type ZnMnO and ZnCoO are close to the ideal values of 5mB and 3mB respectively. Furthermore a clear correlation between the magnetisation per transition metal ion and the ratio of the number of carriers to the number of transition metal donors was established as is expected for carrier induced ferromagnetism for both the Mn and Co doped films. The dependence of the magnetisation on carrier density is similar to that predicted for the transition temperature for a dilute magnetic semiconductor in which the exchange between the transition metal ions is through the free carriers.Comment: 14 pages pd

    Into the Absolute: Recent Paintings by James M. Behan Show Card

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    Show card for Into the Absolute: Recent Paintings by James M. Behan. February 5 - February 19, 1990.https://digitalcommons.udallas.edu/absolute_behan/1000/thumbnail.jp

    Help-seeking behaviors and mental well-being of first year undergraduate university students

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    University students demonstrate poor help-seeking behaviors for their mental health, despite often reporting low levels of mental well-being. The aims of this study were to examine the help-seeking intentions and experiences of first year university students in terms of their mental well-being, and to explore these students’ views on formal (e.g. psychiatrists) and informal (e.g. friends) help-seeking. Students from a university in the Republic of Ireland (n=220) completed an online questionnaire which focused on mental well-being and help-seeking behaviors. Almost a third of students had sought help from a mental health professional. Very few students reported availing of university/online supports. Informal sources of help were more popular than formal sources, and those who would avail and had availed of informal sources demonstrated higher well-being scores. Counselors were the source of professional help most widely used. General practitioners, chaplains, social workers, and family therapists were rated the most helpful. Those with low/average well-being scores were less likely to seek help than those with higher scores. Findings indicate the importance of enhancing public knowledge of mental health issues, and for further examination of students’ knowledge of help-seeking resources in order to improve the help-seeking behaviors and mental well-being of this population group

    Spin polarized transport current in n-type co-doped ZnO thin films measured by Andreev spectroscopy

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    We use point contact Andreev reflection measurements to determine the spin polarization of the transport current in pulse laser deposited thin films of ZnO with 1% Al and with and without 2%Mn. Only films with Mn are ferromagnetic and show spin polarization of the transport current of up to 55 ±\pm 0.5% at 4.2 K, in sharp contrast to measurements of the nonmagnetic films without Mn where the polarization is consistent with zero. Our results imply strongly that ferromagnetism in these Al doped ZnO films requires the presence of Mn.Comment: Published versio

    Alpha-linolenic acid supplementation in Tris extender can improve frozen–thawed bull semen quality

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    The study was conducted to evaluate the effects of α-linolenic acid (ALA) on frozen–thawed quality and fatty acid composition of bull sperm. For that, twenty-four ejaculates obtained from three bulls were diluted in a Tris extender containing 0 (control), 3, 5, 10 and 15 ng/ml of ALA. Extended semen was incubated at 37°C for 15 min, to allow absorption of ALA by sperm cell membrane. The sample was chilled for 2 h, packed into 0.25-ml straws and frozen in liquid nitrogen for 24 h. Subsequently, straws were thawed and evaluated for total sperm motility (computer-assisted semen analysis), membrane functional integrity (hypo-osmotic swelling test), viability (eosin-nigrosin), fatty acid composition (gas chromatography) and lipid peroxidation (thiobarbituric acid-reactive substances (TBARS)). A higher (p < 0.05) percentage of total sperm motility was observed in ALA groups 5 ng/ml (47.74 ± 07) and 10 ng/ml (44.90 ± 0.7) in comparison with control (34.53 ± 3.0), 3 ng/ml (34.40 ± 2.6) and 15 ng/ml (34.60 ± 2.9). Still, the 5 ng/ml ALA group presented a higher (p < 0.05) percentage of viable sperms (74.13 ± 0.8) and sperms with intact membrane (74.46 ± 09) than all other experimental groups. ALA concentration and lipid peroxidation in post-thawed sperm was higher in all treated groups when compared to the control group. As such, the addition of 5 ng/ml of ALA to Tris extender improved quality of frozen–thawed bull spermatozoa

    A Human Right-Based Approach to Dealing with Adverse Events in Residential Care Facilities

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    Managing residential care facilities (RCFs) includes the ability to manage adverse events while maintaining a human rights-based approach to care and support. Literature investigating rights-based approaches in RCFs is scarce; therefore, an investigation of the current approach in RCFs will inform improvements. This study sought to identify whether RCFs in Ireland upheld a rights-based approach during the course of adverse events by analyzing notifications of adverse events from 2021 taken from the Database of Statutory Notifications from Social Care in Ireland. Data analysis was conducted independently by two researchers. Notifications of adverse events were coded according to whether the human rights principles of fairness, respect, equality, dignity, and autonomy were upheld or violated during the adverse event and its subsequent management. There was some evidence of violations, including staff violations during adverse events and their management, as well as residents violating fellow residents’ autonomy, respect, and dignity in notifications of “serious injury” and “allegations of abuse.” However, overall, good practice was identified, with residents’ human rights upheld by staff. Our findings indicate that a rights-based approach to care and support is being upheld during adverse events and their management, which may indicate that such an approach to care and support has been adopte
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