Charged-Particle Motion in Electromagnetic Fields Having at Least One Ignorable Spatial Coordinate

We give a rigorous derivation of a theorem showing that charged particles in an arbitrary electromagnetic field with at least one ignorable spatial coordinate remain forever tied to a given magnetic-field line. Such a situation contrasts the significant motions normal to the magnetic field that are expected in most real three-dimensional systems. It is pointed out that, while the significance of the theorem has not been widely appreciated, it has important consequences for a number of problems and is of particular relevance for the acceleration of cosmic rays by shocks.Comment: 7 pages, emulateapj format, including 1 eps figure, to appear in The Astrophysical Journal, Dec. 10 1998 issu

Violence among foragers: The bioarchaeological record from central California

Spatial and diachronic patterns in skeletal evidence for three forms of violence were evaluated for central California with information from a bioarchaeological database that contains information on 16,820 burials from 329 sites. The most abundant form of violence was sharp force/projectile trauma (462/6278, 7.4%), followed by blunt force craniofacial trauma (264/6202, 4.3%) and trophy-taking/dismemberment (87/12,603, 0.7%). Signs of violence were concentrated in the area with the highest ethnographic population densities (Sacramento River), but also in the southern San Francisco Bay area which seems to have been a contested interface zone between established residents and incoming migrants. Sharp force/projectile trauma was also high in the Sierra Nevada following introduction of the bow and arrow, and violence in general was more common among males, although there is less of a sex-difference among individuals with blunt force craniofacial injuries in central California relative to southern California, suggesting greater participation by females in this form of violence as attested by historic eyewitness accounts. Temporal patterning shows two episodes of elevated violence: the Early Middle Period (500 cal B.C.–cal A.D. 420) when trophytaking/dismemberment peaked, and the Protohistoric/Historic Period (cal A.D. 1720–1899) marked by high levels of blunt force craniofacial and projectile trauma. The Protohistoric/Historic peak, preceded by the appearance of the bow and arrow ca. A.D.1000–1200 and an associated upturn in projectile violence, is attributed to the arrival of Europeans into southwestern North America 250 years before their permanent settlement in California ca. A.D. 1769

Family Interactions Among African American Prostate Cancer Survivors

Prostate cancer affects African Americans at a higher rate than any other ethnic group in the United States. Prostate cancer does not only affect the man with the disease but also affects those individuals who are closest to him, such as his family and friends. Open communication is valuable in coping with stressors that are affiliated with chronic illnesses. This article focuses on family and friend social support of men with prostate cancer. Data analysis revealed that support from family members and friends plays an important role in how men cope with their treatment and recovery from prostate cancer. Originally published Family and Community Health, Vol. 31, No. 3, July-Sep 200

Shared compatibility of ectomycorrhizae on Pseudotsuga menziesii and Betula papyrifera seedlings grown in mixture in soils from southern British Columbia

Seedlings of Pseudotsuga menziesii (Mirb.) Franco and Betula papyrifera Marsh. were grown in the greenhouse in monoculture and dual culture in soils collected from a young mixed species plantation in the southern interior of British Columbia. The objectives of the study were (i) to evaluate the ability of P. menziesii and B. papyrifera to share compatible ectomycorrhizal fungi in order to assess their potential for hyphal linkages and (ii) to study the influence of neighboring seedlings on ectomycorrhizae occurrence. Eleven ectomycorrhizal morphotypes were recognized, seven of which P. menziesii and B. papyrifera seedlings shared in common over 90% of their root tips. The abundance and frequency of Rhizopogon, E-strain I, and Tuber on P. menziesii, and the frequency of Lactarius, Hebeloma, and Cenococcum on B. papyrifera, were affected by the presence of a neighboring seedling. The number of ectomycorrhizal morphotypes shared in common and colonization of root tips by common types were slightly greater when P. menziesii and B. papyrifera were grown in dual culture rather than in monoculture

Models of Star-Planet Magnetic Interaction

Magnetic interactions between a planet and its environment are known to lead to phenomena such as aurorae and shocks in the solar system. The large number of close-in exoplanets that were discovered triggered a renewed interest in magnetic interactions in star-planet systems. Multiple other magnetic effects were then unveiled, such as planet inflation or heating, planet migration, planetary material escape, and even modification of the host star properties. We review here the recent efforts in modelling and understanding magnetic interactions between stars and planets in the context of compact systems. We first provide simple estimates of the effects of magnetic interactions and then detail analytical and numerical models for different representative scenarii. We finally lay out a series of future developments that are needed today to better understand and constrain these fascinating interactions.Comment: 23 pages, 10 figures, accepted as a chapter in the Handbook of Exoplanet

The Grizzly, October 22, 1991

Alumni Return for Homecoming Celebration • Phi Beta Kappa Charter Approved for Ursinus • Thomas Confirmed to Supreme Court • Gibson to Speak at Ursinus • GALA Seeks Recognition • U.S.G.A. Minutes • GALA Comes Out • Modern Medical Imaging • The Vision of Science Through Art • Beware of Bad Moods • Woman Fixing Her Hair? • Critics\u27 Corner: The Fisher King; Sleeping With the Enemy • Giggles Night Club Comedians • Letters: In Defense of Harley; Harassment Response; An Appeal for the Trees • Apples and Oranges • Dining Turf • Bears Blank the Bullets in Homecoming Game • Cross Country Runs to Victory • Field Hockey Strikes Back, Raises Record to 5-5-2 • Volleyball Spikes Cabrini • Lady Bears Cruise to 1st Place • Winds Fill Ursinus\u27 Sails • Soccer Bounces Back with Three Straight Winshttps://digitalcommons.ursinus.edu/grizzlynews/1280/thumbnail.jp

Image acquisition and quality assurance in the Boston Adolescent Neuroimaging of Depression and Anxiety study

The Connectomes Related to Human Diseases (CRHD) initiative was developed with the Human Connectome Project (HCP) to provide high-resolution, open-access, multi-modal MRI data to better understand the neural correlates of human disease. Here, we present an introduction to a CRHD project, the Boston Adolescent Neuroimaging of Depression and Anxiety (BANDA) study, which is collecting multimodal neuroimaging, clinical, and neuropsychological data from 225 adolescents (ages 14–17), 150 of whom are expected to have a diagnosis of depression and/or anxiety. Our transdiagnostic recruitment approach samples the full spectrum of depressed/anxious symptoms and their comorbidity, consistent with NIMH Research Domain Criteria (RDoC). We focused on an age range that is critical for brain development and for the onset of mental illness. This project sought to harmonize imaging sequences, hardware, and functional tasks with other HCP studies, although some changes were made to canonical HCP methods to accommodate our study population and questions. We present a thorough overview of our imaging sequences, hardware, and scanning protocol. We detail similarities and dif-ferences between this study and other HCP studies. We evaluate structural-, diffusion-, and functional-image-quality measures that may be influenced by clinical factors (e.g., disorder, symptomatology). Signal-to-noise and motion estimates from the first 140 adolescents suggest minimal influence of clinical factors on image quality. We anticipate enrollment of an additional 85 participants, most of whom are expected to have a diagnosis of anxiety and/or depression. Clinical and neuropsychological data from the first 140 participants are currently freely available through the National Institute of Mental Health Data Archive (NDA)

Initial evaluation of the Robert Wood Johnson Foundation Nurse Faculty Scholars program

The Robert Wood Johnson Foundation Nurse Faculty Scholars (RWJF NFS) program was developed to enhance the career trajectory of young nursing faculty and to train the next generation of nurse scholars. Although there are publications that describe the RWJF NFS, no evaluative reports have been published. The purpose of this study was to evaluate the first three cohorts (n = 42 scholars) of the RWJF NFS program