Natural linewidth analysis of d-band photoemission from Ag(110)

We report a high-resolution angle-resolved study of photoemission linewidths observed for Ag(110). A careful data analysis yields k$-resolved upper limits for the inverse inelastic lifetimes of$d$-holes at the X-point of the bulk band structure. At the upper$d$-band edge the hole-lifetime is$\tau_h \geq 22 $fs, i.e. more than one order of magnitude larger than predicted for a free-electron gas. Following calculations for$d$-hole dynamics in Cu (I.\ Campillo et al., Phys. Rev. Lett., in press) we interpret the lifetime enhancement by a small scattering cross-section of $d$- and $sp$-states below the Fermi level. With increasing distance to $E_F$ the $d$-hole lifetimes get shorter because of the rapidly increasing density of d-states and contributions of intra-$d$-band scattering processes, but remain clearly above free-electron-model predictions.Comment: 14 pages, 7 figure

Raising Student Achievement Levels Through Target-setting and Academic Monitoring: A Case Study of Developments at Key Stage 3 in a Secondary School

Evidence for the conclusions and recommendations are based on interviews with tutors and students from Year 8 conducted by the Head of Year, who then provides an overview from her perspective. The findings are contrasted against the examples of effective target-setting provided by the DfEE Standards and Effectiveness Unit (DfEE, 1998b) and the Office for Standards in Education (Ofsted, 1996). The new scheme is also reviewed in the light of the call for equal opportunities by, amongst others, the Department for Education and Employment (DfEE, 1998c) and against the body of evidence provided by the research on school improvement (e.g. Stoll and Mortimore, 1995; Creemers, 1997

Interaction of Public and Private Employment: Evidence from a German Government Move

We use the move of the seat of the German government from Bonn to Berlin in 1999 to test competing views about the impact of public employment on private sector activity in a local labor market. A relocated public sector job might create new jobs in an area as it increases demand for locally-produced goods and services, or crowd out existing jobs due to upward pressure on housing rents. Using employment data from a panel of a 50% sample of establishments across 190 Berlin postcodes, we apply a treatment intensity approach which takes the possibility of spillovers into account. Results indicate that the arrival of 100 public sector jobs into an area generates 55 additional jobs in the private sector. There is evidence of spillovers: relocations up to a distance of 1km from a postcode boundary increases employment in the private sector by 36 jobs. These effects are coming through job gains in the service sector, while manufacturing employment is not influenced by the relocation

Ultrafast spatio-temporal dynamics of terahertz generation by ionizing two-color femtosecond pulses in gases

We present a combined theoretical and experimental study of spatio-temporal propagation effects in terahertz (THz) generation in gases using two-color ionizing laser pulses. The observed strong broadening of the THz spectra with increasing gas pressure reveals the prominent role of spatio-temporal reshaping and of a plasma-induced blue-shift of the pump pulses in the generation process. Results obtained from (3+1)-dimensional simulations are in good agreement with experimental findings and clarify the mechanisms responsible for THz emission

Strange Quark PDFs and Implications for Drell-Yan Boson Production at the LHC

Global analyses of Parton Distribution Functions (PDFs) have provided incisive constraints on the up and down quark components of the proton, but constraining the other flavor degrees of freedom is more challenging. Higher-order theory predictions and new data sets have contributed to recent improvements. Despite these efforts, the strange quark PDF has a sizable uncertainty, particularly in the small x region. We examine the constraints from experiment and theory, and investigate the impact of this uncertainty on LHC observables. In particular, we study W/Z production to see how the s-quark uncertainty propagates to these observables, and examine the extent to which precise measurements at the LHC can provide additional information on the proton flavor structure.Comment: 14 pages, 11 figures, added reference

The impact of public employment on private sector activity: Evidence from Berlin

We use the move of the seat of the German government from Bonn to Berlin in 1999 to test competing views about the impact of public employment on private sector activity in a local labor market. Using employment data from a 50% sample of establishments across 190 Berlin postcodes, we apply a treatment intensity approach which takes the possibility of spillovers into account. Results indicate that the arrival of 100 public sector jobs into an area generates 55 additional jobs in the private sector. There is evidence of spillovers: relocations up to a distance of 1km from a postcode boundary increases employment in the private sector by 36 jobs. These effects are coming through job gains in the service sector, while manufacturing employment is not influenced by the relocation

Water Quality and Sanitation, Aquatic Flora Fauna

Division of Power (DOP