Single Leptoquark Production at Hadron Colliders

Leptoquarks can be produced in pairs by gluon--gluon fusion and quark--antiquark annihilation at hadron colliders. While HERA is the proper machine for single production of $(eu)$ and $(ed)$ type leptoquarks, the flavor species of ($\mu u$), ($\mu d$) and ($\tau u$), ($\tau d$) type leptoquarks can be produced at hadron colliders very efficiently. Besides exploiting gluon-quark collisions, leptoquarks can also be produced singly by colliding the quarks in one proton beam with leptons $e,\mu,\tau$ generated by splitting photons which are radiated off the quarks in the other proton beam. For Yukawa couplings of the size $\alpha$ leptoquark masses up to about 300~GeV can be generated at the Tevatron while the LHC can produce leptoquarks with masses up to about 3~TeV. [Leptoquarks involving heavy quarks can be produced singly at a lower rate, determined by the heavy flavor flux in the proton beam.]Comment: 7 LaTex pages plus 2 uuencoded postscript files appended, DESY 94--086, UCD--94--17, UMN--TH--1258/94. Latex and postscipt files are also available via anonymous ftp at ucdhep.ucdavis.edu in directory [anonymous.ohnemus.ucd-94-17

Does a Brief Mindfulness Training Enhance Heartfulness in Students? Results of a Pilot Study

(1) Background: There is robust evidence that mindfulness trainings enhance mindfulness as operationalized in Western psychology, but evidence about their effect on aspects of heartfulness is sparse. This study seeks to test whether a brief mindfulness training enhances heart qualities, including self-compassion, gratitude, and the generation of feelings of happiness. (2) Methods: Eighteen students enrolled in a mindfulness training that was offered as part of an interdisciplinary class. The training consisted of five training sessions and four booster sessions of 45 minutes each over the course of nine weeks. Mindfulness was measured with the Five Facet Mindfulness Questionnaire-Short Form (FFMQ-SF) and self-compassion was measured with the Self-Compassion Scale Short Form (SCS-SF). In addition, two items were drawn from the Caring for Bliss Scale (CBS) measuring gratitude and the generation of feelings of happiness in the present moment. Assessments were conducted before the training (pre), after the training (post), and four weeks after the training (follow-up). (3) Results: Results showed that mindfulness, general self-compassion, and generating feelings of happiness increased from pre to post, whereas self-critical attitudes decreased and that these changes were maintained at follow-up. Gratitude increased from pre to post and then decreased from post to follow-up. (4) Conclusions: A brief mindfulness training seems to be beneficial for students to improve mindfulness and aspects of heartfulness, but further research is needed to investigate the effectiveness of the training relative to a cohort or active control group

Mindfulness and acceptance-based trainings for fostering self-care and reducing stress in mental health professionals: A systematic review

This review summarizes the effectiveness of Mindfulness-Based Stress Reduction (MBSR), Mindfulness-Based Cognitive Therapy (MBCT), Mindful Self-Compassion (MSC), and Acceptance and Commitment Therapy (ACT) to foster self-care and reduce stress in mental health professionals. Twenty-four quantitative articles from PsycInfo and PubMed were identified that focused on mindfulness, self-compassion, psychological flexibility, stress, burnout, or psychological well-being. All MBSR and MBCT studies lacked active control conditions, but some of the ACT studies and one MSC study included an active control. Most studies support evidence that all training programs tend to improve mindfulness and some also self-compassion. In addition, psychological flexibility was measured in the ACT studies and tends to improve over time. Further, MBSR, MSC, and ACT tend to reduce stress or burnout. The results were less supportive for psychological well-being. The value of the various training adaptations as well as directions for future research are discussed

Psychological Distress and Well-Being among Students of Health Disciplines: The Importance of Academic Satisfaction

Background: Research on the mental health of students in health disciplines mainly focuses on psychological distress and nursing and medical students. This study aimed to investigate the psychological well-being and distress and related factors among undergraduate students training in eight different health-related tracks in Geneva, Switzerland. Methods: This cross-sectional study used established self-filled scales for anxiety, depression, stress, psychological well-being, and study satisfaction. Descriptive statistics and hierarchical regression analyses were applied. Results: In October 2019, out of 2835 invited students, 915 (32%) completed the survey. Lower academic satisfaction scores were strongly associated with depression (β = −0.26, p < 0.001), anxiety (β = −0.27, p < 0.001), and stress (β = −0.70, p < 0.001), while higher scores were associated with psychological well-being (β = 0.70, p < 0.001). Being female was strongly associated with anxiety and stress but not with depression or psychological well-being. Increased age was associated with enhanced psychological well-being. The nature of the academic training had a lesser impact on mental health and the academic year had none. Conclusion: Academic satisfaction strongly predicts depression, anxiety, stress, and psychological well-being. Training institutions should address the underlying factors that can improve students’ satisfaction with their studies while ensuring that they have access to psychosocial services that help them cope with mental distress and enhance their psychological well-bein

Innovative methodology to transfer conventional GC-MS heroin profiling to UHPLC-MS/MS

Nowadays, in forensic laboratories, heroin profiling is frequently carried out by gas chromatography coupled with mass spectrometry (GC-MS). This analytical technique is well established, provides good sensitivity and reproducibility, and allows the use of large databases. Despite those benefits, recently introduced analytical techniques, such as ultra-high-pressure liquid chromatography (UHPLC), could offer better chromatographic performance, which needs to be considered to increase the analysis throughput for heroin profiling. With the latter, chromatographic conditions were optimized through commercial modeling software and two atmospheric pressure ionization sources were evaluated. Data obtained from UHPLC-MS/MS were thus transferred, thanks to mathematical models to mimic GC-MS data. A calibration and a validation set of representative heroin samples were selected among the database to establish a transfer methodology and assess the models' abilities to transfer using principal component analysis and hierarchical classification analysis. These abilities were evaluated by computing the frequency of successful classification of UHPLC-MS/MS data among GC-MS database. Seven mathematical models were tested to adjust UHPLC-MS/MS data to GC-MS data. A simplified mathematical model was finally selected and offered a frequency of successful transfer equal to 95%. Figur

Defect Production in Slow First Order Phase Transitions

We study the formation of vortices in a U(1) gauge theory following a first-order transition proceeding by bubble nucleation, in particular the effect of a low velocity of expansion of the bubble walls. To do this, we use a two-dimensional model in which bubbles are nucleated at random points in a plane and at random times and then expand at some velocity $v_{\rm b}<c$. Within each bubble, the phase angle is assigned one of three discrete values. When bubbles collide, magnetic `fluxons' appear: if the phases are different, a fluxon--anti-fluxon pair is formed. These fluxons are eventually trapped in three-bubble collisions when they may annihilate or form quantized vortices. We study in particular the effect of changing the bubble expansion speed on the vortex density and the extent of vortex--anti-vortex correlation.Comment: 13 pages, RevTeX, 15 uuencoded postscript figure

Partial Derivation of Transformation Properties of Quarks and Leptons

Under the assumptions that $SU(3)_c\times U(1)_Y \times G^{\prime}$ with $G^{\prime}$ simple is a local symmetry group at high energies, that color is parity-conserving, and the Y-charges are irreducible, we show that anomaly constraints imply the minimal set of fermions is fifteen in number. Given this minimal set, we further show that $G^{\prime}$ must be $SU(2)$ and the unbroken gauge symmetry is {\it either} color {\it or} the product of color with electric charge.Comment: 9 pages, UMDHEP 94-72 and IFP-487-UN

Possible large phase in psi(2S) -> 1-0- Decays

The strong and the electromagnetic amplitudes are analyzed on the basis of the measurements of J/psi, psi(2S) -> 1-0- in e+e- experiments. The currently available experimental information is revised with inclusion of the contribution from e+e- -> gamma * -> 1-0- . The study shows that a large phase around minus 90 degree between the strong and the electromagnetic amplitudes could not be ruled out by the experimental data for psi(2S).Comment: 4 page

Single-run separation of closely related cationic and anionic compounds by CE-ESI-MS: application to the simultaneous analysis of melamine and its analogs in milk

In recent years, two adulteration incidents concerning the addition of melamine, a nitrogen-rich industrial small polar compound, to pet food and infant formula products have occurred in China. These issues prompted laboratories to develop methods for the analysis of melamine and related compounds in a wide variety of food products and ingredients. In this context, a CE-ESI-MS method was developed to simultaneously analyze melamine and its related products (ammeline, ammelide and cyanuric acid) that possess close physico-chemical properties. This method allows the simultaneous analysis of both cations and anions in a single run, using CE to divide the run into two time segments in normal polarity mode. For this purpose, ESI polarity was switched once during the run, increasing sensitivity and data quality. The method was applied to spiked powdered milk and melamine-contaminated powdered milk, with two sample preparation procedures