WIMP searches with gamma rays in the Fermi era: challenges, methods and results

The launch of the gamma-ray telescope Fermi Large Area Telescope (Fermi-LAT) started a pivotal period in indirect detection of dark matter. By outperforming expectations, for the first time a robust and stringent test of the paradigm of weakly interacting massive particles (WIMPs) is within reach. In this paper, we discuss astrophysical targets for WIMP detection and the challenges they present, review the analysis tools which have been employed to tackle these challenges, and summarize the status of constraints on and the claimed detections in the WIMP parameter space. Methods and results will be discussed in comparison to Imaging Air Cherenkov Telescopes. We also provide an outlook on short term and longer term developments.Comment: 72 pages, 7 figures, Invited review for Journal of Experimental and Theoretical Physics,v3: added a few references, addressed referee comment

The Approach: A Promise of Warmth Inside

Walking up those stairs is always a treat. The tacit knowledge that you are moving towards a hidden gem: a space most don’t know to find. Salt water, wood smoke, and roasted coffee perfume the air. But the best part of all is the intention. This is not a space to go to out of necessity or convenience. This is a space for slow sips and long reprieves. This thesis explores many themes, but at the heart is the idea of The Approach: how we come to an object is just as important as the actual moment when we meet the object. The Approach pulls the outside world in, building opportunities for solace. Woven into the core of this research is the theme of tension in harmony: contrast that creates a sum greater than its parts. I seek to better understand how to harness balance in opposition. I search for moments on the stairs, when the promise of warmth beckons from just around the corner

Conceptions of headteachers concerning their role

The study is an exploration of the role conceptions of headteachers for various aspects of their work with pupils, teachers and parents, and the expectations that heads believe teachers and parents hold for the role of the head as school leader. A Headteacher Role Definition Instrument (HRDI) was constructed with the assistance of headteachers and tested. It was completed by a national sample of Infant, Junior and Secondary school headteachers from schools throughout England and Wales. In the first part of the study, the interpositional analysis, a number of hypotheses were tested in connection with the relationship between situational factors (the type, the size, and the location of schools) end personal factors (the age and the sex of their incumbents) and head teachers' role conceptions. In the initial section of the second part of the study, the phenomenological analysis, each of eleven headteacher groups was examined separately on each item of the HRDI to ascertain the pattern of relationships between head teachers' role conceptions and their attributed expectations to teachers and to parents. A typology of nine perceived role type situations was deduced. In the final section of the second part of the study, an adequate stimulus weighting criterion was introduced by which to identify 44 HRDI items on which headteachers—in-general held common phenomenological perceptions. Ihe head teacher's world was described by reference to the typology of role type situations and the 44 items of headteacher behaviour. In the interpositional analysis, hypotheses which related the type and the size of the school to the role conceptions of their headteach­ers were supported. So, also, were hypotheses concerning relationships between age, sex, end headteachers' role conceptions. A null hypothesis in respect of the location of schools and the role conceptions of their headteachers was not rejected. In the phenomenological analysis, the headteacher was described as the occupant of a boundary position which served as a point of articula­tion between the internal and external systems of the school. Headteachers' mandatory role conceptions were directed primarily towards the internal system of the school and were marked by high consensual agreement among heads themselves and, so they believed, among teachers and parents. Those items of headteacher behaviour which articulated the internal and external systems of the school were generally marked by less consensual agreement both actual and attributed, and were identified as potentially - conflictful for headteachers. The commonest source of such conflict was held to arise out of headteachers' perceptions of the incompatibility of teacher expectations for professional autonomy and boundary maintenance and parent expectations for representation and influence in specific aspects of the school's affairs. The findings reported here are suggested as useful basic material content for lecture, seminar, and simulation techniques in connection with courses concerned with the in-service training of head teachers

A Biography of the Second Justice Harlan

A Review of John Marshall: Great Dissenter of the Warren Court by Tinsley E. Yarbroug

Democracy as Civic Conversation: Book Review Of: Talking It Through: Puzzles of American Democracy. by Robert W. Bennett

Book review of: Talking It Through: Puzzles of American Democracy. By Robert W. Bennett. Cornell University Press. Pp. 223. Reviewed by: Louis R. Cohen

The Potential of Synergistic Static, Dynamic and Speculative Loop Nest Optimizations for Automatic Parallelization

Research in automatic parallelization of loop-centric programs started with static analysis, then broadened its arsenal to include dynamic inspection-execution and speculative execution, the best results involving hybrid static-dynamic schemes. Beyond the detection of parallelism in a sequential program, scalable parallelization on many-core processors involves hard and interesting parallelism adaptation and mapping challenges. These challenges include tailoring data locality to the memory hierarchy, structuring independent tasks hierarchically to exploit multiple levels of parallelism, tuning the synchronization grain, balancing the execution load, decoupling the execution into thread-level pipelines, and leveraging heterogeneous hardware with specialized accelerators. The polyhedral framework allows to model, construct and apply very complex loop nest transformations addressing most of the parallelism adaptation and mapping challenges. But apart from hardware-specific, back-end oriented transformations (if-conversion, trace scheduling, value prediction), loop nest optimization has essentially ignored dynamic and speculative techniques. Research in polyhedral compilation recently reached a significant milestone towards the support of dynamic, data-dependent control flow. This opens a large avenue for blending dynamic analyses and speculative techniques with advanced loop nest optimizations. Selecting real-world examples from SPEC benchmarks and numerical kernels, we make a case for the design of synergistic static, dynamic and speculative loop transformation techniques. We also sketch the embedding of dynamic information, including speculative assumptions, in the heart of affine transformation search spaces