Low and high intensity velocity selective coherent population trapping in a two-level system

An experimental investigation is made of sub-recoil cooling by velocity selective coherent population trapping in a two-level system in Sr. The experiment is carried out using the narrow linewidth intercombination line at 689 nm. Here, the ratio between the recoil shift and the linewidth is as high as 0.64. We show that, on top of a broader momentum profile, subrecoil features develop, whose amplitude is strongly dependent on the detuning from resonance. We attribute this structure to a velocity selective coherent population trapping mechanism. We also show that the population trapping phenomenon leads to complex momentum profiles in the case of highly saturated transitions, displaying a multitude of subrecoil features at integer multiples of the recoil momentum.Comment: 6 pages and 7 figure

Porphyrias associated with malignant tumors: Results of treatment with ionizing irradiation

Background: Porphyrin metabolism disorders, known as porphyria, represent inherited or acquired diseases. The development of porphyria due to light sensibility occurs especially with exposure to wavelengths in the range of 300-700 nm. Skin reactions and neurovisceral dysfunctions are known side effects of ionizing irradiation. It can be postulated that during or after ionizing irradiation treatment of patients affected with tumor and porphyria, severe side effects might appear, in contrast to patients without porphyria. This paper describes the treatment of 2 patients affected with tumor and concomitant porphyria. Patients: One female patient suffering from intermittent porphyria and breast cancer and one male patient suffering from porphyria cutanea tarda and bladder cancer were treated with ionizing irradiation (electrons and photons). No abnormalities nor any severe general or local side effects could be observed. Conclusion: Radiation therapy is not a `stimulating' factor in activating porphyria symptoms

Radio-chemotherapy as a preoperative treatment for advanced rectal cancer. Evaluation of down-staging and morbidity

Background: The standard therapy for patients with clinically resectable rectal cancer is generally considered to be surgery, If the patient is diagnosed with advanced disease, postoperative radiochemotherapy (RCT) is usually recommended. In our study we aimed to investigate and analyze the effectiveness and toxicity of preoperative pelvic radiotherapy in combination with 5-fluorouracil (5-FU) in locally advanced rectal cancer. Patients and Methods: From June 1999 to September 2001 we evaluated 50 consecutive patients {[}37 male and 13 female; average age 65.1 (range 46-79.5) years] with locally advanced rectal carcinoma. 32 patients were staged as uT3, 14 as uT4, and 4 as uT2. Regarding N-staging, 22 patients were diagnosed as ONO. 2 patients had distant metastases, with liver metastases in both instances. Conformal irradiation was performed with a box technique 4-field technique) with a dose of 45 Gy (5 x 1.8 Gy per week for a total of 25 sessions). From days 1-5 and 29-33, all patients received 5-FU (500 mg/m(2) per day, as a continuous i.v. injection). Results: Remission was observed in 28 patients (56%), with down-staging of at least one T-stage. A better success rate was achieved for patients with deep-seated tumors (64% of the patients in this group). Complete remission was observed in 4 patients (8.0%) and progression in 3 (6.0%). 15 patients had no detectable change in tumor staging (30.0%). A surgical R0 resection could be achieved in 43 patients, an R1 resection (minimal margins in 7. Side effects and toxicity (common toxicity criteria) of RCT included grade I-II dysuria in 5 patients (10%), grade I-II diarrhea in 20 patients (40%), and severe diarrhea in 2 patients (4.0%). Grade I-II skin reaction was noticed in 22 patients (44.0%), severe skin reaction only in 1 patient. Regarding acute postoperative morbidity, abscess and fistula formation was noted in 8 patients (16.0%), with anastomosis leakage in 7 (14%). Conclusion: Preoperative radiotherapy appears to be a feasible therapeutic approach with moderate toxicity and the potential to induce down-staging. The data presented in this study confirm the preliminary reports on this neoadjuvant treatment

Coherent flash of light emitted by a cold atomic cloud

When a resonant laser sent on an optically thick cold atomic cloud is abruptly switched off, a coherent flash of light is emitted in the forward direction. This transient phenomenon is observed due to the highly resonant character of the atomic scatterers. We analyze quantitatively its spatio-temporal properties and show very good agreement with theoretical predictions. Based on complementary experiments, the phase of the coherent field is reconstructed without interferometric tools.Comment: Submitted to Phys. Rev. Let

Do We See Eye to Eye? Moderators of Correspondence Between Student and Faculty Evaluations of Day-to-Day Teaching

Students and instructors show moderate levels of agreement about the quality of day-to-day teaching. In the present study, we replicated and extended this finding by asking how correspondence between student and instructor ratings is moderated by time of semester and student demographic variables. Participants included 137 students and 5 instructors. On 10 separate days, students and instructors rated teaching effectiveness and challenge level of the material. Multilevel modeling indicated that student and instructor ratings of teaching effectiveness converged overall, but more advanced students and Caucasian students converged more closely with instructors. Student and instructor ratings of challenge converged early but diverged later in the semester. These results extend our knowledge about the connection between student and faculty judgments of teaching

Color in context: psychological context moderates the influence of red on approach- and avoidance-motivated behavior.

A basic premise of the recently proffered color-in-context model is that the influence of color on psychological functioning varies as a function of the psychological context in which color is perceived. Some research has examined the appetitive and aversive implications of viewing the color red in romance- and achievement-relevant contexts, respectively, but in all existing empirical work approach and avoidance behavior has been studied in separate tasks and separate experiments. Research is needed to directly test whether red influences the same behavior differently depending entirely on psychological context. The present experiment was designed to put this premise to direct test in romance- and achievement-relevant contexts within the same experimental paradigm involving walking behavior. Our results revealed that exposure to red (but not blue) indeed has differential implications for walking behavior as a function of the context in which the color is perceived. Red increased the speed with which participants walked to an ostensible interview about dating (a romance-relevant context), but decreased the speed with which they walked to an ostensible interview about intelligence (an achievement-relevant context). These results are the first direct evidence that the influence of red on psychological functioning in humans varies by psychological context. Our findings contribute to both the literature on color psychology and the broader, emerging literature on the influence of context on basic psychological processes

Self-evaluation in advanced power searching and mapping with google MOOCs

While there is a large amount of work on creating autograded massive open online courses (MOOCs), some kinds of complex, qualitative exam questions are still beyond the current state of the art. For MOOCs that need to deal with these kinds of questions, it is not possible for a small course staff to grade students ’ qualitative work. To test the efficacy of self-evaluation as a method for complex-question evaluation, students in two Google MOOCs have submitted projects and evaluated their own work. For both courses, teaching assistants graded a random sample of papers and compared their grades with self-evaluated student grades. We found that many of the submitted projects were of very high quality, and that a large majority of self-evaluated projects were accurately evaluated, scoring within just a few points of the gold standard grading

Cooperative Emission of a Coherent Superflash of Light

We investigate the transient coherent transmission of light through an optically thick cold stron-tium gas. We observe a coherent superflash just after an abrupt probe extinction, with peak intensity more than three times the incident one. We show that this coherent superflash is a direct signature of the cooperative forward emission of the atoms. By engineering fast transient phenomena on the incident field, we give a clear and simple picture of the physical mechanisms at play.Comment: 4 Fig., 5 page

Lexical Derivation of the PINT Taxonomy of Goals: Prominence, Inclusiveness, Negativity Prevention, and Tradition

What do people want? Few questions are more fundamental to psychological science than this. Yet, existing taxonomies disagree on both the number and content of goals. We thus adopted a lexical approach and investigated the structure of goal-relevant words from the natural English lexicon. Through an intensive rating process, 1,060 goal-relevant English words were first located. In Studies 1-2, two relatively large and diverse samples (total n = 1,026) rated their commitment to approaching or avoiding these goals. Principal component analyses yielded 4 replicable components: Prominence, Inclusiveness, Negativity prevention, and Tradition (the PINT Taxonomy). Study 3-7 (total n = 1,396) supported the 4-factor structure of an abbreviated scale and found systematic differences in their relationships with past goal-content measures, the Big 5 traits, affect, and need satisfaction. This investigation thus provides a data-driven taxonomy of higher-order goal-content and opens up a wide variety of fascinating lines for future research