Estimating oceanic primary production using vertical irradiance and chlorophyll profiles from ocean gliders in the North Atlantic

An autonomous underwater vehicle (Seaglider) has been used to estimate marine primary production (PP) using a combination of irradiance and fluorescence vertical profiles. This method provides estimates for depth-resolved and temporally evolving PP on fine spatial scales in the absence of ship-based calibrations. We describe techniques to correct for known issues associated with long autonomous deployments such as sensor calibration drift and fluorescence quenching. Comparisons were made between the Seaglider, stable isotope (13C), and satellite estimates of PP. The Seaglider-based PP estimates were comparable to both satellite estimates and stable isotope measurements

Performance of buried channel n-type MOSFETs in 0.18-μm CMOS image sensor process

Buried channel (BC) MOSFETs are known to have better noise performance than surface channel (SC) MOSFETs when used as source followers in modern Charge Coupled Devices (CCD). CMOS image sensors find increasing range of applications and compete with CCDs in high performance imaging, however BC transistors are rarely used in CMOS. As a part of the development of charge storage using BC CCDs in CMOS, we designed and manufactured deep depletion BC n-type MOSFETs in 0.18 μm CMOS image sensor process. The transistors are designed in a way similar to the source followers in a typical BC CCD. In this paper we report the results from their characterization and compare with enhancement mode and “zero-threshold” SC devices. In addition to the detailed current-voltage and noise measurements, semiconductor device simulation results are presented to illustrate and understand the different conditions affecting the channel conduction and the noise performance of the BC transistors at low operating voltages. We show that the biasing of the BC transistors has to be carefully adjusted for optimal operation, and that their noise performance at the right operating conditions can be superior to SC devices, despite their lower gain as in-pixel source followers

Radiation Hardness Studies in a CCD with High-Speed Column Parallel Readout

Charge Coupled Devices (CCDs) have been successfully used in several high energy physics experiments over the past two decades. Their high spatial resolution and thin sensitive layers make them an excellent tool for studying short-lived particles. The Linear Collider Flavour Identification (LCFI) collaboration is developing Column-Parallel CCDs (CPCCDs) for the vertex detector of the International Linear Collider (ILC). The CPCCDs can be read out many times faster than standard CCDs, significantly increasing their operating speed. The results of detailed simulations of the charge transfer inefficiency (CTI) of a prototype CPCCD are reported and studies of the influence of gate voltage on the CTI described. The effects of bulk radiation damage on the CTI of a CPCCD are studied by simulating the effects of two electron trap levels, 0.17 and 0.44 eV, at different concentrations and operating temperatures. The dependence of the CTI on different occupancy levels (percentage of hit pixels) and readout frequencies is also studied. The optimal operating temperature for the CPCCD, where the effects of the charge trapping are at a minimum, is found to be about 230 K for the range of readout speeds proposed for the ILC. The results of the full simulation have been compared with a simple analytic model.Comment: 3 pages, 6 figures; presented at IEEE'07, ALCPG'07, ICATPP'0

On the K^+D Interaction at Low Energies

The Kd reactions are considered in the impulse approximation with NN final-state interactions (NN FSI) taken into account. The realistic parameters for the KN phase shifts are used. The "quasi-elastic" energy region, in which the elementary KN interaction is predominantly elastic, is considered. The theoretical predictions are compared with the data on the K^+d->K^+pn, K^+d->K^0pp, K^+d->K^+d and K^+d total cross sections. The NN FSI effect in the reaction K^+d->K^+pn has been found to be large. The predictions for the Kd cross sections are also given for slow kaons, produced from phi(1020) decays, as the functions of the isoscalar KN scattering length a_0. These predictions can be used to extract the value of a_0 from the data.Comment: 22 pages, 5 figure

General practitioners' evaluation of community psychiatric services: responsiveness to change of the General Practitioner Experiences Questionnaire (GPEQ)

<p>Abstract</p> <p>Background</p> <p>Instruments have been developed to assess professional views of the quality of care but have rarely been tested for responsiveness to change. The objective of this study was to test the responsiveness of the General Practitioner Experiences Questionnaire (GPEQ) for the measurement of Community Mental Health Centres in Norway.</p> <p>Methods</p> <p>National surveys were conducted in Norway in 2006 (n = 2,415) and 2008 (n = 2,209) to measure general practitioners' evaluation of community mental health centres. GPs evaluated the centres by means of a postal questionnaire, consisting of questions focused on centre quality and cooperation with GPs. As part of the national surveys 75 GPs in 2006 and 66 GPs in 2008 evaluated Hamar community mental health centre. Between the surveys, several quality improvement initiatives were implemented which were directed at cooperation with and guidance for GPs in Stange municipality, one of eight municipalities in Hamar centre catchment area. The main outcome measures were changes in GPEQ scores from 2006 to 2008 for GPs evaluating Hamar community mental health centre from Stange municipality, and changes in scores for GPs in the other seven municipalities and nationally which were assessed for statistical significance.</p> <p>Results</p> <p>GPs in Stange municipality rated Hamar community mental health centre significantly better on the guidance scale in 2008 than in 2006; on a 0-100 scale where 100 represents the best possible experiences the score was 26.5 in 2006 and 58.3 in 2008 (p < 0.001). Apart from one item about workforce situation, none of the other scales and items showed significant changes. The control group from the other seven municipalities gave significantly poorer rating for the emergency situation scale, the workforce situation scale and seven items in 2008 than in 2006. The national results showed small differences between 2006 and 2008, even though several scales and items were significantly different. A question about changes in centre performance over the last 2-3 years showed that 82% of GPs from Stange municipality reported that Hamar community mental health centre had improved, compared to only 36% from the other seven municipalities and 40% nationally which was statistically significant.</p> <p>Conclusions</p> <p>Following the implementation of an initiative designed to enhance service quality, the GPEQ identified expected changes in the guidance scale for the intervention group, indicating that the instrument is responsive to change. The worsening of services for GPs in the control group evaluating Hamar centre warrants further study.</p

Measurement of the branching ratios of the Z0 into heavy quarks

We measure the hadronic branching ratios of the Z0 boson into heavy quarks: Rb=Gamma(Z0->bb)/Gamma(Z0->hadrons) and Rc=Gamma(Z0->cc/Gamma(Z0->hadrons) using a multi-tag technique. The measurement was performed using about 400,000 hadronic Z0 events recorded in the SLD experiment at SLAC between 1996 and 1998. The small and stable SLC beam spot and the CCD-based vertex detector were used to reconstruct bottom and charm hadron decay vertices with high efficiency and purity, which enables us to measure most efficiencies from data. We obtain, Rb=0.21604 +- 0.00098(stat.) +- 0.00073(syst.) -+ 0.00012(Rc) and, Rc= 0.1744 +- 0.0031(stat.) +- 0.0020(syst.) -+ 0.0006(Rb)Comment: 37 pages, 8 figures, to be submitted to Phys. Rev. D version 2: changed title to ratios, used common D production fractions for Rb and Rc and corrected Zgamma interference. Identical to PRD submissio

Search for time-dependent B0s - B0s-bar oscillations using a vertex charge dipole technique

We report a search for B0s - B0s-bar oscillations using a sample of 400,000 hadronic Z0 decays collected by the SLD experiment. The analysis takes advantage of the electron beam polarization as well as information from the hemisphere opposite that of the reconstructed B decay to tag the B production flavor. The excellent resolution provided by the pixel CCD vertex detector is exploited to cleanly reconstruct both B and cascade D decay vertices, and tag the B decay flavor from the charge difference between them. We exclude the following values of the B0s - B0s-bar oscillation frequency: Delta m_s < 4.9 ps-1 and 7.9 < Delta m_s < 10.3 ps-1 at the 95% confidence level.Comment: 18 pages, 3 figures, replaced by version accepted for publication in Phys.Rev.D; results differ slightly from first versio

Measurement of the Charged Multiplicities in b, c and Light Quark Events from Z0 Decays

Average charged multiplicities have been measured separately in $b$, $c$ and light quark ($u,d,s$) events from $Z^0$ decays measured in the SLD experiment. Impact parameters of charged tracks were used to select enriched samples of $b$ and light quark events, and reconstructed charmed mesons were used to select $c$ quark events. We measured the charged multiplicities: $\bar{n}_{uds} = 20.21 \pm 0.10 (\rm{stat.})\pm 0.22(\rm{syst.})$, $\bar{n}_{c} = 21.28 \pm 0.46(\rm{stat.}) ^{+0.41}_{-0.36}(\rm{syst.})$ $\bar{n}_{b} = 23.14 \pm 0.10(\rm{stat.}) ^{+0.38}_{-0.37}(\rm{syst.})$, from which we derived the differences between the total average charged multiplicities of $c$ or $b$ quark events and light quark events: $\Delta \bar{n}_c = 1.07 \pm 0.47(\rm{stat.})^{+0.36}_{-0.30}(\rm{syst.})$ and $\Delta \bar{n}_b = 2.93 \pm 0.14(\rm{stat.})^{+0.30}_{-0.29}(\rm{syst.})$. We compared these measurements with those at lower center-of-mass energies and with perturbative QCD predictions. These combined results are in agreement with the QCD expectations and disfavor the hypothesis of flavor-independent fragmentation.Comment: 19 pages LaTex, 4 EPS figures, to appear in Physics Letters