bluuebunny/crossref_metadata_2025 huggingface dataset:
Make Magazine Online: No-Battery Remote (Faraday Generator)
Authors: MacIsaac Dan
Published: September 2009

Make Magazine (motto: technology on your time) is a technology-hacking magazine dedicated to folk interested in using inexpensive technology in unintended ways, or remanufacturing technology to suit their personal whims. Typically this involves making clever robots, barbeques, model rocket telemetry, autopilots for RC planes, and many electronics projects. The project featured here under the first link describes how to make a Faraday generator to replace batteries for a TV remote control using a plastic tube wrapped in magnet wire containing a Nd magnet that is shaken by hand. I buy my Nd magnets in bulk from Master Magnetics http://www.mastermagnetics.com.
Green Diode Laser Pointers Have Now Dropped in Cost to About $10
Authors: MacIsaac Dan
Published: September 2009

Also on the cheap apparatus hunt, handheld green diode laser pointers are now $8–12 each from www.amazon.com or www.ebay.com—search for “green laser pointers.” Because green light is in the center of the sensitivity of our eyes, we see 5 mW of green light MUCH more clearly than the same power red diode laser. Green lasers are preferred for pointing out astronomical objects in the night sky or for those faint wave diffraction experiments. A group of my students worked on green laser pointer diffraction experiments this past summer, and their work can be seen at http://physicsed.buffalostate.edu/eurp09.
More Physics Cheap Apparatus From HarborFreight.com
Authors: MacIsaac Dan
Published: September 2009

Finally, I can't talk about cheap physics apparatus without including HarborFreight.com. Worth a visit for the $10 digital multimeter alone ($3 on sale), $20 sound meter, $11 IR thermometer, and many other inexpensive geeky goodies. Every lab group can have cheap durable voltmeters and ammeters as necessary. Our introductory labs stock about four dozen of these meters, and while we blow lots of fuses we have yet to electrically destroy one (though several have met their physical doom for the good of the discipline). http://harborfreight.com, search on the appropriate keyword.
Success … by Accident or Design? Outliers: The Story of Success: Malcolm Gladwell
Authors: Bartlett Albert Allen
Published: September 2009

Success … by Accident or Design? Outliers: The Story of Success, by Malcolm Gladwell, Little Brown and Company, New York, NY, (2008), 309 pp., $27.99.
In Vivo Efficacy of 1- and 2-Gram Human Simulated Prolonged Infusions of Doripenem against
Pseudomonas aeruginosa
Authors: Crandon Jared L. , Bulik Catharine C. , Nicolau David P.
Published: September 2009

Doripenem is a new carbapenem antimicrobial with activity against a range of gram-negative organisms, including
Pseudomonas aeruginosa
. Previous animal studies have shown efficacy of a 500-mg dose of doripenem given as a 4-h infusion against
P. aeruginosa
with MICs of ≤4 μg/ml. The purpose of this study is to evaluate the efficacy of 1- and 2-g-dose prolonged infusions of doripenem against a wide range of
P. aeruginosa
isolates in the neutropenic murine thigh model. Eighteen clinical
P. aeruginosa
isolates (MIC range, 2 to 32 μg/ml) were used; 15 of these were multidrug resistant. After infection, groups of mice were administered doripenem doses designed to simulate the free time above the MIC (
f
T>MIC) observed in humans given 1 or 2 g of doripenem every 8 h as a 4-h infusion. Efficacy correlated well with published
f
T>MIC bactericidal targets of 40%. After 24 h, 1- and 2-g doses achieved approximately ≥2 log decreases in CFU against isolates with MICs of ≤8 and 16 μg/ml, respectively (
f
T>MIC range, 52.5 to 95%). Results with organisms with higher MICs, where
f
T>MIC was 0%, were variable, including both increases and decreases in CFU. Compared with 1-g doses, statistically greater efficacy was noted for 2-g doses against three of the eight isolates with MICs of ≥16 μg/ml. While MIC distributions of
P. aeruginosa
at present necessitate increased exposures for only the most-resistant isolates, the ability of increased doses to achieve pharmacodynamic targets and the efficacy observed when these targets were attained could prove useful when these resistant isolates are encountered.
ACHN-490, a Neoglycoside with Potent In Vitro Activity against Multidrug-Resistant
Klebsiella pneumoniae
Isolates
Authors: Endimiani Andrea , Hujer Kristine M. , Hujer Andrea M. , Armstrong Eliana S. , Choudhary Yuvraj , Aggen James B. , Bonomo Robert A.
Published: September 2009

The in vitro activity of ACHN-490, a novel aminoglycoside (“neoglycoside”), was evaluated against 102 multidrug-resistant (MDR)
Klebsiella pneumoniae
strains, including a subset of 25 strains producing the KPC carbapenemase. MIC
50
values for gentamicin, tobramycin, and amikacin were 8 μg/ml, 32 μg/ml, and 2 μg/ml, respectively; MIC
90
values for the same antimicrobials were ≥64 μg/ml, ≥64 μg/ml, and 32 μg/ml, respectively. ACHN-490 showed an MIC
50
of 0.5 μg/ml and an MIC
90
of 1 μg/ml, which are significantly lower than those of comparator aminoglycosides. ACHN-490 represents a promising aminoglycoside for the treatment of MDR
K. pneumoniae
isolates, including those producing KPC β-lactamase.
Postantibiotic Effect of Ceftaroline against Gram-Positive Organisms
Authors: Pankuch G. A. , Appelbaum P. C.
Published: September 2009

The postantibiotic effects (PAEs), postantibiotic sub-MIC effects (PA-SMEs), and sub-MIC effects (SMEs) of ceftaroline, a novel injectable cephalosporin, were determined for 15 gram-positive organisms. The pneumococcal, staphylococcal, and enterococcal PAEs were 0.8 to 1.8 h, 0.7 to 2.2 h, and 0.2 to 1.1 h, respectively. The corresponding PA-SMEs (0.4 times the MIC) were 2.5 to 6.7 h, 2.9 to >0.0 h, and 7.9 to >10.3 h, respectively. The PA-SMEs were longer than the PAEs, suggesting that sub-MIC levels extend the PAE of ceftaroline against gram-positive cocci.
Manganese(II)-ion-selective electrode based on 2,2′-bis(salicylideneamino)azobenzene incorporated in poly(vinyl chloride) matrix
Authors: Gholivand Mohammad Bagher , Gorji Maryam , Joshaghani Mohammad
Published: September 2009

A new PVC membrane electrode highly selective to Mn(II), based on 2,2′-bis(salicylideneamino)azobenzene as an ionophore. The electrode exhibits a Nernstian response to Mn(II) ions over a concentration range 0.8 × 10–1–1.1 × 10–7 mol l–1 with a slope of 30.5 ± 0.5 mV per decade and detection limit 5.5 × 10–8 mol l–1. The electrode was used for 45 days at the minimum without any measurable potential divergence. Also, the electrode revealed a fairly good discrimination ability between Mn(II) ions and some cations and anions. The electrode was also utilized as indicator electrode in the potentiometric titration of Mn(II) with EDTA and in determination of Mn(II) in drug as well as tape and river water.
New carbocyclic nucleoside analogues built on a bicyclo[2.2.2]octane-2,2-dimethanol template
Authors: Hřebabecký Hubert , Dračínský Martin , Holý Antonín
Published: September 2009

(1R*,4S*,6S*)-6-(6-Chloro-9H-purin-9-yl)bicyclo[2.2.2]octane-2,2-dimethanol (22) and (1R*,4R*,5S*)-5-(6-chloro-9H-purin-9-yl)bicyclo[2.2.2]octane-2,2-dimethanol (17) were prepared from (1R*,4R*)-bicyclo[2.2.2]oct-5-ene-2,2-dimethanediyl dibenzoate (7) using two approaches. The first procedure consists in hydroboration of 7, separation of obtained 6-exo-hydroxy derivative 8 and 5-exo-hydroxy derivative 9, conversion of 8 and 9 to endo-hydroxy derivatives 12 and 13, respectively, and the Mitsunobu reaction with 6-chloropurine. Only 5-(6-chloropurinyl) analogue 16 was obtained in an acceptable yield. The target analog 17 was prepared by reductive debenzoylation of 16. The further reactions were hydroboration of 7, treatment with hydroxylamine-O-sulfonic acid and debenzoylation. Chloropurine analogues 17 and 22 were built on the obtained 6-exo-amino- and 5-exo-aminobicyclo[2.2.2]octane-2,2-dimethanols 18 and 19, respectively. Compounds 17 and 22 were converted to adenine (23, 24) and 6-(cyclopropylamino)purine analogues (25, 26).
Paternal occupation and retinoblastoma: a case–control study based on data for Great Britain 1962–1999
Authors: MacCarthy A , Bunch K J , Fear N T , King J C , Vincent T J , Murphy M F G
Published: September 2009

Objectives:

To examine the association between paternal occupational exposures and retinoblastoma using birth registration data for cases from the National Registry of Childhood Tumours (NRCT) and controls from the general population of Great Britain.

Methods:

A case–control study of paternal occupational data for 1318 cases of retinoblastoma, born and diagnosed in Great Britain between 1962 and 1999, and 1318 controls matched on sex, date of birth and birth registration sub-district. Paternal occupations at birth were grouped according to inferred exposure using an occupational exposure classification scheme. A conditional (matched) case–control analysis was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for each paternal occupational exposure group.

Results:

For non-heritable retinoblastoma, a statistically significant increased risk was found with father’s definite occupational exposure to oil mists in metal working (OR = 1.85 (95% CI 1.05 to 3.36)). Together with a (non-significant) risk (OR = 1.64 (0.73 to 3.83)) amongst the heritable cases, this occupational exposure was also associated with a significant increased risk when all retinoblastoma cases were considered together (OR = 1.77 (1.12 to 2.85)). No statistically significant associations were observed for other exposure groups.

Conclusions:

Our finding for exposure to oil mists in metal working (a subset of metal workers) is not directly comparable to those for metal working previously reported in the literature. Overall, our findings do not support the hypothesis that paternal occupational exposure is an important aetiological factor for retinoblastoma, however, the study has low power and other methodological limitations.
The Location and Structure of the Precambrian Kisseynew Gneiss Domain of Northern Saskatchewan
Authors: Pearson David E.
Published: September 2009

The Kisseynew Gneisses occupy a large structural basin which can be traced from Reindeer Lake to Kisseynew Lake in Saskatchewan, and for at least 70 mi (113 km) east of the provincial boundary with Manitoba. The domain is flanked on the south and west sides by metavolcanics and metasediments of the Amisk Series, and by their presumed equivalents of a higher metamorphic grade. The northern boundary is composed of foliated granodiorites.The rocks have been assigned to two lithological groups, the Nokomis and the Sherridon, which correspond to similar divisions of the Kisseynew gneisses in Manitoba. The Nokomis is predominantly a graphite bearing pelitic gneiss containing cordierite and sillimanite, with subsidiary amphibole bearing gneisses and calc-silicates. It is characterized by a low aeromagnetic relief (< 61 300 γ). The Sherridon, by contrast, is characterized by a higher aeromagnetic signature (61 300–62 350 γ), being a magnetite bearing semi-pelitic gneiss.The Kisseynew basin has a complex structure resulting from three phases of deformation. Large recumbent and reclined folds formed in the first period of deformation have been refolded during a second period of deformation producing complex interference patterns. A third phase of deformation produced a series of regional elbow-like folds with east–northeasterly trending axial surface traces.
An Extrusive Basaltic Komatiite from a Canadian Archean Metavolcanic Belt
Authors: Brooks C. , Hart S.
Published: September 2009

A pillowed mafic metavolcanic from an Archean volcanic belt near Wawa, Ontario contains over 16% MgO and has a CaO/Al2O3 ratio of 1.5. It is chemically similar to the basaltic komatiites described from the Archean of South Africa. Because komatiites are related chemically and stratigraphically to Archean basalt–dacite–rhyolite suites, we propose that all these volcanic types should be considered genetically in terms of an Archean volcanic or island arc tectonic regime.
A Study of Fenitization in Mafic Rocks, with Special Reference to the Callander Bay Complex
Authors: Currie K. L. , Ferguson J.
Published: September 2009

Garnet amphibolite lenses around the Callander Bay alkaline carbonatite complex are transformed by fenitization into alkali feldspar – hastingsite rocks, partly by ionic exchange reactions, and partly by replacement of mafic minerals. The chemical composition of the mafic rocks converges with fenitization towards that of salic fenites. Literature data suggest that these observations are typical of mafic fenites. The fenitizing solutions at Callander Bay were alkali chloride brines 10–25 molar in strength with K/Na + K ratios of 0.23, and a K/H+ ratio of 30. These brines arose from the silicate portion of the complex, and the close association of carbonatite and fenite stems from a factor common to both carbonatite and alkaline silicate rocks, probably a high water content in the parental magma.
Igneous and Tectonic Events in Northeastern Cape Breton Island, Nova Scotia
Authors: Wiebe Robert A.
Published: September 2009

The geology of northern Cape Breton Island is characterized by two structurally and compositionally distinct metamorphic units and an extended history of igneous activity ranging in age from Precambrian to Devonian. The older metamorphic unit (George River Group(?)) is composed of metamorphosed psammitic and semipelitic rocks with some distinctive quartzite and coarse-grained marble layers. It was deformed and probably metamorphosed, prior to emplacement of Precambrian diorites. A younger metamorphic unit (Fourchu Group(?)) consists mostly of metamorphosed intermediate to acidic volcanic and volcaniclastic rocks and rests with angular unconformity on the George River Group (?) and the diorites. Shallow-level plutonic activity was contemporaneous with the Fourchu Group(?). Younger leucocratic granodiorites (410 m.y.) were emplaced at a depth of about 15 km and require deposition of a thick surficial sequence during the early Paleozoic (between 560 and 410 m.y.). Mississippian sedimentary rocks rest unconformably on all of the older rocks.Igneous rocks of the Precambrian are dominantly andesitic and are similar to present-day suites in island arcs associated with subduction zones. Their composition requires that they be generated in the mantle. The average compositions of igneous rocks emplaced from late Precambrian to Devonian time become more granitic and probably reflect increasing generation of magma from crustal sources.
The Catamaran Fault, North-Central New Brunswick
Authors: Anderson F. D.
Published: September 2009

The Catamaran Fault cuts pre-Carboniferous rocks of the Miramichi Geanticline in north-central New Brunswick. It has been examined for about 60 miles (100 km) across the intrusive and metamorphic core of the geanticline and into the Siluro-Devonian flank rocks. The fault strikes easterly in the core and northeasterly in the flanks.Where displacement could be determined movement on the fault is mainly right lateral strike-slip. There is no evidence for major dip-slip. Fracture analysis indicates that faulting was in response to a northwest-southeast trending principal compressive stress similar to that deduced for other faults in the Maritime Provinces. Latest movement along the fault was post-Middle Devonian (i.e. post-dates the emplacement of the Acadian granite) and pre-Pennsylvanian.The Catamaran Fault may extend eastward along a fault possibly underlying Miramichi Bay and continuing under the Gulf of St. Lawrence, and westward along a southwesterly trending fault in western New Brunswick. As such the Catamaran Fault may exceed 250 miles (400 km) in length.
Crustal Seismic Measurements over the Appalachian Front from Shots in Labrador and Quebec
Authors: Overton A.
Published: September 2009

During June and July of 1968 the Geological Survey of Canada participated in the Dominion Observatories crustal seismic experiment centered on the Grenville front in north central Quebec. Participation was to the extent of recording the shots of the experiment at locations subadjacent to the Appalachian front from Rimouski and Rivière Du Loup, Québec to Edmundston, New Brunswick. Recordings from a three component station were taken on photographic paper, and also on frequency modulated magnetic tape. A preliminary study of 19 Pn first arrivals results in velocities for the upper mantle ranging from 8.08 km/s to 8.23 km/s with a mean of 8.15 km/s under the shots. Under the stations Pn events show velocities for the upper mantle ranging from 7.81 km/s to 8.65 km/s with a mean of 8.15 km/s. A least-squares time-term analysis for Pn events results in a velocity of 7.94 ± 0.42 km/s at the 90% confidence level. This solution shows large residual times ranging between ±0.7 s which probably imply complex geological structures near the shots and the recording stations. Time and distance data are summarized as well as details of computations.
A Mathematical Model Predicting Tidal Current Velocities in the Strait of Georgia – Juan de Fuca Strait System
Authors: Dewey J. M. , McMillin D. J.
Published: September 2009

A one-dimensional model for calculating the time variation of tidal current velocities throughout the Strait of Georgia – Juan de Fuca Strait system is described. It is intended to use the calculated velocity field as input to a particle transport model predicting the motion of foreign material released in the tidal stream. The velocity calculations are based on the detailed channel dimensions and on observed tidal heights at a number of stations in the system. Only the hydrodynamic equation of continuity is used, which avoids the necessity of using arbitrarily adjusted roughness coefficients. As a single boundary condition it is assumed that there is a constant zero velocity at the head of the channel, where the volume flow rate is small compared to other parts of the system. The calculated velocity field compares well with the limited number of observations that have been made.
Geothermal Data from the Granduc Area, Northern Coast Mountains of British Columbia
Authors: Mathews W. H.
Published: September 2009

Temperature measurements have been obtained from 80 points along the Granduc haulage tunnel, at depths of as much as 1.5 km below the surface. These fit, within 1 °C, a simplified model assuming, among other things, uniform thermal conductivity of the rocks and a temperature at rock–glacier contacts of 0 °C. For these assumptions a generalized thermal gradient (with effects of topographic irregularity removed) is about 26 mK m−1 (26 °C/km). With the thermal conductivity of a suite of rocks from the tunnel averaging 2.72 ± 12 W m−1K−1 (6.50 ±.28 cal/cm s °C) present heat flow of about 73 mW m−2 (1.74 μcal/cm2 s) can be derived.
A Note on the Age of Basalt Dikes in the Mealy Mountains, Labrador, Canada
Authors: Gittins J.
Published: September 2009

K–Ar ages of 1123 and 1078 m.y. were obtained on two specimens from basalt dikes occupying joints in the Mealy Mountains anorthosite massif, Lake Melville, Labrador.
A MATHEMATICAL MODEL OF BLOOD FLOW IN A CATHETERIZED ARTERY WITH A STENOSIS
Authors: CHAKRAVARTY S. , SEN S.
Published: September 2009

The present theoretical investigation is based on the flow characteristics of blood in a catheterized bifurcated artery under stenotic conditions through the use of a mathematical model. The geometry of the bifurcated arterial segment having stenosis in the daughter arterial lumen frequently appearing in the diseased arteries causing malfunction of the cardiovascular system, is constructed mathematically with the introduction of suitable curvatures at the lateral junction and the flow divider. The changed flow pattern in the catheterized artery is studied by considering the pressure gradient as pulsatile in nature. The flowing blood contained in the arterial segment under consideration is treated to be Newtonian and the flow is considered to be two dimensional. The motion of the arterial wall and its effect on local fluid mechanics is not ruled out from the present study. The flow analysis applies the two-dimensional unsteady incompressible nonlinear Navier–Stokes equations for Newtonian fluids. The resulting nonlinear differential equations together with the boundary conditions following the radial coordinate transformation are solved numerically by adopting a finite difference scheme. An extensive quantitative analysis is performed at the end of the paper in order to estimate the effects of the catheter, the wall distensibility, the stenosis and the viscous dissipation of blood in the flow characteristics of the blood stream and the wall shear stress so as to validate the applicability of the present mathematical model. Some of the several important findings of the present investigation discussed at length include the changing pattern of the flow-field in the parent aorta, the occurrence of back flow at and beyond the apex with the formation of several flow separation zones, and the generation of higher wall shear stresses on the inner wall than on the outer wall surface owing to the arterial catheterization. The arterial catheterization does influence the viscous dissipation more remarkably in the parent duct till its apex than in the branch arteries.
Comparing Group Discussion in Virtual and Physical Environments
Authors: Friedman Doron , Karniel Yuval , Dinur Amit Lavie
Published: September 2009

One of the main promises of collaborative virtual environments (CVEs) is that they would decrease the need for travel and face-to-face meetings. In this study we aim at comparing the dynamics and content of group discussions in desktop virtual environments with physical-world discussions. We have conducted an experiment in which four groups of 7–12 participants each carried out a political discussion on the same topic; specifically, global warming. Two groups conducted the experiment in a face-to-face setting and two other groups conducted a similar discussion inside the virtual world SecondLife ( http://www.secondlife.com ). Virtual-world discussions were found to include shorter sentences on average, have a smaller number of themes discussed, discuss a smaller number of themes in depth, and require a longer time for discussion threads to form. In this paper we provide a quantitative analysis of the similarities and differences between virtual-world and physical-world discussions.
Virtual Experiences, Physical Behaviors: The Effect of Presence on Imitation of an Eating Avatar
Authors: Fox Jesse , Bailenson Jeremy , Binney Joseph
Published: September 2009

In this study, the role of presence in the imitation of a virtual model was examined. Immersive virtual environment technology (IVET) was used to create photorealistic virtual representations of the self that were depicted eating food in a virtual world. Changes in the virtual environment (via a changing or unchanging body) were incorporated to create variance in perceived subjective presence. Based on previous research, presence was hypothesized to affect the relationship between the environmental manipulations and the behavioral outcome of imitating the avatar's eating behavior. Here we show that presence did indeed affect imitation, but that the effects varied for men and women in accordance with previous research on sex differences in eating behavior. Men who experienced high presence were more likely than low presence men to imitate the virtual model and eat candy, whereas women who experienced high presence were more likely than low presence women to suppress the behavior and not eat candy.
Using Radial Outflow to Provide Depth Information During Teleoperation
Authors: Gomer Joshua A , Dash Coleman H , Moore Kristin S , Pagano Christopher C
Published: September 2009

Practical experience has shown that teleoperators have difficulty perceiving aspects of remotely operated robots and their environments (e.g., Casper & Murphy, 2003; Smets, 1995; Tittle, Roesler, & Woods, 2002). Previous research has shown that head motions can provide effective information about depth (Bingham, & Pagano, 1998; Pagano & Bingham, 1998). In three experiments, a method for improving depth perception was investigated, where participants viewed remote targets with a moving camera. The camera was mounted on a teleoperated robotic arm that oscillated toward and away from white squares against black space, producing expansion and contraction of targets on a video monitor. Participants viewed this expansion and contraction and then reported the distance between the remote camera and the targets. Under different experimental conditions, motions of the remote camera arm were coupled with the participants' head movements, were controlled by a joystick, or followed a set of preprogrammed oscillatory motions. Under each of these conditions, participants' distance judgments varied semantically with actual target distances. In addition, the third experiment demonstrated that using familiar objects and providing feedback could be a successful method of training. This was also the case when applied to a condition where distance feedback was not provided and unfamiliar targets were used. The results indicate that the use of radial outflow produced by active or passive front-to-back camera motions and training with familiar objects may be effective strategies for improving depth perception in teleoperation.
Recent Declines in Western U.S. Snowpack in the Context of Twentieth-Century Climate Variability
Authors: McCabe Gregory J. , Wolock David M.
Published: September 2009

A monthly snow accumulation and melt model was used with monthly Precipitation-elevation Regressions on Independent Slopes Model (PRISM) temperature and precipitation data to generate time series of 1 April snow water equivalent (SWE) for 1900 through 2008 in the western United States. Averaged across the western United States, SWE generally was higher than long-term (1900–2008) average conditions during the periods 1900–25, 1944–55, and 1966–82; SWE was lower than long-term average conditions during the periods 1926–43, 1957–65, and 1984–2008. During the period 1900–2008, the temporal pattern in winter precipitation exhibited wetter-than-average and drier-than-average decadal-scale periods with no long-term increasing or decreasing trend. Winter temperature generally was below average from 1900 to the mid-1950s, close to average from the mid-1950s to the mid-1980s, and above average from the mid-1980s to 2008. In general, periods of higher-than-average SWE have been associated with higher precipitation and lower temperature. Since about 1980, western U.S. winter temperatures have been consistently higher than long-term average values, and the resultant lower-than-average SWE values have been only partially offset by periods of higher-than-average precipitation. The post-1980 lower-than-average SWE conditions in the western United States are unprecedented within the context of twentieth-century climate and estimated SWE.
Evaluation of TRMM Ground-Validation Radar-Rain Errors Using Rain Gauge Measurements
Authors: Wang Jianxin , Wolff David B.
Published: September 2009

Ground-validation (GV) radar-rain products are often utilized for validation of the Tropical Rainfall Measuring Mission (TRMM) space-based rain estimates, and, hence, quantitative evaluation of the GV radar-rain product error characteristics is vital. This study uses quality-controlled gauge data to compare with TRMM GV radar rain rates in an effort to provide such error characteristics. The results show that significant differences of concurrent radar–gauge rain rates exist at various time scales ranging from 5 min to 1 day, despite lower overall long-term bias. However, the differences between the radar area-averaged rain rates and gauge point rain rates cannot be explained as due to radar error only. The error variance separation method is adapted to partition the variance of radar–gauge differences into the gauge area–point error variance and radar-rain estimation error variance. The results provide relatively reliable quantitative uncertainty evaluation of TRMM GV radar-rain estimates at various time scales and are helpful to understand better the differences between measured radar and gauge rain rates. It is envisaged that this study will contribute to better utilization of GV radar-rain products to validate versatile space-based rain estimates from TRMM, as well as the proposed Global Precipitation Measurement satellite and other satellites.
The Echo Size Distribution of Precipitating Shallow Cumuli
Authors: Trivej Panu , Stevens Bjorn
Published: September 2009

S-band radar surveillance scans of precipitating shallow convection are analyzed. The scans are complied from 52 days of near-continuous measurements in the winter trades of the North Atlantic during the Rain in Cumulus over the Ocean (RICO) field campaign. After being analyzed and filtered to exclude spurious returns, the scans are segmented to identify contiguous returns, or echoes. The echo size and reflectivity statistics are then analyzed. A new normalization method is developed to account for biases associated with the nonuniformity in the native radar grid. The echo area distribution robustly exhibits power-law scaling up until sizes of about 10 km2, with a scaling exponent of about −1.1. At larger sizes the scaling behavior breaks down and varies more markedly across subsamples of the data. Conditional sampling suggests that the scaling behavior of the larger echoes does, however, approach that of the smaller echoes as echo coverage increases, which supports the idea of a limiting distribution. Departures from this limiting distribution are argued to reflect finite size effects, modulated by the presence of a capping inversion whose height and strength varies across the samples.
How Much Energy Is Transferred from the Winds to the Thermocline on ENSO Time Scales?
Authors: Brown Jaclyn N. , Fedorov Alexey V.
Published: September 2009

The dynamics of El Niño–Southern Oscillation (ENSO) are studied in terms of the balance between energy input from the winds (via wind power) and changes in the storage of available potential energy in the tropical ocean. Presently, there are broad differences in the way global general circulation models simulate the dynamics, magnitude, and phase of ENSO events; hence, there is a need for simple, physically based metrics to allow for model evaluation. This energy description is a basinwide, integral, quantitative approach, ideal for intermodel comparison, that assesses model behavior in the subsurface ocean. Here it is applied to a range of ocean models and data assimilations within ENSO spatial and temporal scales. The onset of an El Niño is characterized by a decrease in wind power that leads to a decrease in available potential energy, and hence a flatter thermocline. In contrast, La Niña events are preceded by an increase in wind power that leads to an increase in the available potential energy and a steeper thermocline. The wind power alters the available potential energy via buoyancy power, associated with vertical mass fluxes that modify the slope of the isopycnals. Only a fraction of wind power is converted to buoyancy power. The efficiency of this conversion γ is estimated in this study at 50%–60%. Once the energy is delivered to the thermocline it is subject to small, but important, diffusive dissipation. It is estimated that this dissipation sets the e-folding damping rate α for the available potential energy on the order of 1 yr−1. The authors propose to use the efficiency γ and the damping rate α as two energy-based metrics for evaluating dissipative properties of the ocean component of general circulation models, providing a simple method for understanding subsurface ENSO dynamics and a diagnostic tool for exploring differences between the models.
Seasonal Mixed Layer Heat Balance of the Southwestern Tropical Indian Ocean*
Authors: Foltz Gregory R. , Vialard Jérôme , Praveen Kumar B. , McPhaden Michael J.
Published: September 2009

Sea surface temperature (SST) in the southwestern tropical Indian Ocean exerts a significant influence on global climate through its influence on the Indian summer monsoon and Northern Hemisphere atmospheric circulation. In this study, measurements from a long-term moored buoy are used in conjunction with satellite, in situ, and atmospheric reanalysis datasets to analyze the seasonal mixed layer heat balance in the thermocline ridge region of the southwestern tropical Indian Ocean. This region is characterized by a shallow mean thermocline (90 m, as measured by the 20°C isotherm) and pronounced seasonal cycles of Ekman pumping and SST (seasonal ranges of −0.1 to 0.6 m day−1 and 26°–29.5°C, respectively). It is found that surface heat fluxes and horizontal heat advection contribute significantly to the seasonal cycle of mixed layer heat storage. The net surface heat flux tends to warm the mixed layer throughout the year and is strongest during boreal fall and winter, when surface shortwave radiation is highest and latent heat loss is weakest. Horizontal heat advection provides warming during boreal summer and fall, when southwestward surface currents and horizontal SST gradients are strongest, and is close to zero during the remainder of the year. Vertical turbulent mixing, estimated as a residual in the heat balance, also undergoes a significant seasonal cycle. Cooling from this term is strongest in boreal summer, when surface wind and buoyancy forcing are strongest, the thermocline ridge is shallow (<90 m), and the mixed layer is deepening. These empirical results provide a framework for addressing intraseasonal and interannual climate variations, which are dynamically linked to the seasonal cycle, in the southwestern tropical Indian Ocean. They also provide a quantitative basis for assessing the accuracy of numerical ocean model simulations in the region.
Greenland Ice Sheet Surface Mass-Balance Modeling in a 131-Yr Perspective, 1950–2080
Authors: Mernild Sebastian H. , Liston Glen E. , Hiemstra Christopher A. , Christensen Jens H.
Published: September 2009

Fluctuations in the Greenland ice sheet (GrIS) surface mass balance (SMB) and freshwater influx to the surrounding oceans closely follow climate fluctuations and are of considerable importance to the global eustatic sea level rise. A state-of-the-art snow-evolution modeling system (SnowModel) was used to simulate variations in the GrIS melt extent, surface water balance components, changes in SMB, and freshwater influx to the ocean. The simulations are based on the Intergovernmental Panel on Climate Change scenario A1B modeled by the HIRHAM4 regional climate model (RCM) using boundary conditions from the ECHAM5 atmosphere–ocean general circulation model (AOGCM) from 1950 through 2080. In situ meteorological station [Greenland Climate Network (GC-Net) and World Meteorological Organization (WMO) Danish Meteorological Institute (DMI)] observations from inside and outside the GrIS were used to validate and correct RCM output data before they were used as input for SnowModel. Satellite observations and independent SMB studies were used to validate the SnowModel output and confirm the model’s robustness. The authors simulated an ∼90% increase in end-of-summer surface melt extent (0.483 × 106 km2) from 1950 to 2080 and a melt index (above 2000-m elevation) increase of 138% (1.96 × 106 km2 × days). The greatest difference in melt extent occurred in the southern part of the GrIS, and the greatest changes in the number of melt days were seen in the eastern part of the GrIS (∼50%–70%) and were lowest in the west (∼20%–30%). The rate of SMB loss, largely tied to changes in ablation processes, leads to an enhanced average loss of 331 km3 from 1950 to 2080 and an average SMB level of −99 km3 for the period 2070–80. GrIS surface freshwater runoff yielded a eustatic rise in sea level from 0.8 ± 0.1 (1950–59) to 1.9 ± 0.1 mm (2070–80) sea level equivalent (SLE) yr−1. The accumulated GrIS freshwater runoff contribution from surface melting equaled 160-mm SLE from 1950 through 2080.
Application of the Multigrid Method to the Two-Dimensional Doppler Radar Radial Velocity Data Assimilation
Authors: Li Wei , Xie Yuanfu , Deng Shiow-Ming , Wang Qi
Published: September 2009

In recent years, the Earth System Research Laboratory (ESRL) of the National Oceanic and Atmospheric Administration (NOAA) has developed a space and time mesoscale analysis system (STMAS), which is currently a sequential three-dimensional variational data assimilation (3DVAR) system and is developing into a sequential 4DVAR in the near future. It is implemented by using a multigrid method based on a variational approach to generate grid analyses. This study is to test how STMAS deals with 2D Doppler radar radial velocity and to what degree the 2D Doppler radar radial velocity can improve the conventional (in situ) observation analysis. Two idealized experiments and one experiment with real Doppler radar radial velocity data, handled by STMAS, demonstrated significant improvement of the conventional observation analysis. Because the radar radial wind data can provide additional wind information (even it is incomplete: e.g., missing tangential wind vector), the analyses by assimilating both radial wind data and conventional data showed better results than those by assimilating only conventional data. Especially in the case of sparse conventional data, radar radial wind data can provide significant information and improve the analyses considerably.
An Isofactorial Change-of-Scale Model for the Wind Speed Probability Density Function
Authors: Morrissey Mark L. , Albers Angie , Greene J. Scott , Postawko Susan
Published: September 2009

The wind speed probability density function (PDF) is used in a variety of applications in meteorology, oceanography, and climatology usually as a dataset comparison tool of a function of a quantity such as momentum flux or wind power density. The wind speed PDF is also a function of measurement scale and sampling error. Thus, quantities derived from a function of the wind PDF estimated from measurements taken at different scales may yield vastly different results. This is particularly true in the assessment of wind power density and studies of model subgrid-scale processes related to surface energy fluxes. This paper presents a method of estimating the PDF of wind speed representing a specific scale, whether that is in time, space, or time–space. The concepts used have been developed in the field of nonlinear geostatistics but have rarely been applied to meteorological problems. The method uses an expansion of orthogonal polynomials that incorporates a scaling parameter whose values can be found from the variance of wind speed at the desired scale. Possible uses of this technique are for scale homogenization of model or satellite datasets used in comparison studies, investigations of subgrid-scale processes for development of parameterization schemes, or wind power density assessment.
Validation of Cloud-Resolving Model Background Data for Cloud Data Assimilation
Authors: Polkinghorne Rosanne , Vukicevic Tomislava , Evans K. Franklin
Published: September 2009

Results from a cloud-resolving model are systematically compared with a variety of observations, both ground based and satellite, in order to better understand the mean background errors and their correlations. This is a step in the direction of developing a background error covariance matrix for use in cloud data assimilation. Observation sources include the Geostationary Operational Environmental Satellite (GOES), the Atmospheric Emitted Radiance Interferometer (AERI), a microwave radiometer (MWR), radiosonde, and cloud radar. When exploring model biases in temperature, precipitable water vapor, and liquid water path, a warm and moist bias at night and a cool and dry bias during the day are observed. Values for the background decorrelation length of water variables are determined. In addition, a dynamic cloud mask is presented to give more control in the assimilation of cloudy satellite radiances, allowing different cloud types to be excluded from the assimilation as well as establishing values for the maximum residuals to be considered.
False Alarms, Tornado Warnings, and Tornado Casualties
Authors: Simmons Kevin M. , Sutter Daniel
Published: September 2009

This paper extends prior research on the societal value of tornado warnings to the impact of false alarms. Intuition and theory suggest that false alarms will reduce the response to warnings, yet little evidence of a “false alarm effect” has been unearthed. This paper exploits differences in the false-alarm ratio across the United States to test for a false-alarm effect in a regression model of tornado casualties from 1986 to 2004. A statistically significant and large false-alarm effect is found: tornadoes that occur in an area with a higher false-alarm ratio kill and injure more people, everything else being constant. The effect is consistent across false-alarm ratios defined over different geographies and time intervals. A one-standard-deviation increase in the false-alarm ratio increases expected fatalities by between 12% and 29% and increases expected injuries by between 14% and 32%. The reduction in the national tornado false-alarm ratio over the period reduced fatalities by 4%–11% and injuries by 4%–13%. The casualty effects of false alarms and warning lead times are approximately equal in magnitude, suggesting that the National Weather Service could not reduce casualties by trading off a higher probability of detection for a higher false-alarm ratio, or vice versa.
Making Science Useful to Decision Makers: Climate Forecasts, Water Management, and Knowledge Networks
Authors: Feldman David L. , Ingram Helen M.
Published: September 2009

Moving from climate science to adaptive action is an immense challenge, especially in highly institutionalized sectors such as water resources. Knowledge networks are valuable strategies to put climate information to use. They overcome barriers to information adoption such as stovepipes, pipelines, and restricted decision space, and they can be responsive to issues of salience and the hurdles of reliability, credibility, and trust. Collaboration and adaptive management efforts among resource managers and forecast producers with differing missions show that mutual learning informed by climate information can occur among scientists of different disciplinary backgrounds and between scientists and water managers. The authors show how, through construction of knowledge networks and their institutionalization through boundary organizations focused on salient problems, climate information can positively affect water resources decision making.
Weather-Index Drought Insurance in Burkina-Faso: Assessment of Its Potential Interest to Farmers
Authors: Berg Alexis , Quirion Philippe , Sultan Benjamin
Published: September 2009

By using a detailed agricultural and climate dataset over Burkina-Faso and simple assumptions regarding the form of an insurance contract, the authors investigate the potential economic efficiency for farmers of a weather-index insurance system in this country. To do so, the results of more than 3000 simulated contracts applied to 30 districts, 21 yr (1984–2004), and five crops (cotton, millet, sorghum, maize, and groundnut) are explored. It is found that such an insurance system, even based on a simple weather index like cumulative rainfall during the rainy season, can present a significant economic efficiency for some crops and districts. The determinants of the efficiency of such contracts are analyzed in terms of yield/index correlations and yield variability. As a consequence of these two main determinants, the farmer’s gain from an insurance contract is higher in the driest part of the country. In the same way, maize and groundnuts are the most suitable to implement an insurance system since their respective yields show a large variance and a generally high correlation with the weather index. However, the implementation of a real weather-index insurance system in West Africa raises a number of key practical issues related to cultural, economic, and institutional aspects.
Hydrologic Interdependencies and Human Cooperation: The Process of Adapting to Droughts
Authors: Endter-Wada Joanna , Selfa Theresa , Welsh Lisa W.
Published: September 2009

The Bear River Basin, which includes portions of Idaho, Utah, and Wyoming in the United States, has a dynamic history of human hydrologic adaptations in relation to a highly variable water supply. These adaptations are embedded in a geographical setting highly influenced by the legal, policy, and institutional contexts that govern allocation of water in this generally arid region. In response to several years of drought and a historically low water year in 2004, water users in the Bear River Basin tested the efficacy of the “law of the river” and innovative agreements that they had negotiated in recent years to help mitigate impacts related to water shortages. Three innovations were identified as being key to a successful response to the 2004 drought: 1) a precedent-setting voluntary settlement agreement, 2) technical work in river modeling and instrumentation, and 3) extraordinary communication strategies employed throughout the drought. Based on case study research and utilizing a “ways of knowing” theoretical framework, the authors report on an unfolding contemporary history of how people in the Bear River Basin have learned to deal with uncertainties and risks associated with both droughts and floods. Their story has important implications for the understanding of conflict and cooperation in water systems, management of transboundary waters, and the promotion of sustainable water resource governance.
Changes in Ice Storm Impacts over Time: 1886–2000
Authors: Call David A.
Published: September 2009

Ice storms have a variety of negative effects on society. Through an analysis of newspaper accounts of nine exceptional ice storms, the most widespread and longest lasting impact is the loss of electrical power. Power outages also cause secondary effects, such as carbon monoxide poisoning and fire, and they can force people to leave their homes because of a lack of heat. Other impacts of ice storms are transportation disruptions, school and business closings, and economic losses to agriculture and some business sectors. However, some businesses, such as those associated with the hospitality sector, actually benefit from ice storms.

Modern power outages have a longer duration than those associated with earlier storms. Rural areas are most likely to suffer from long power outages because utilities prioritize areas with greater numbers of customers and because fallen trees may limit accessibility. Several suggestions for reducing electrical disruption, such as aggressive tree-trimming programs and burial of lines, are analyzed. While these may help, less reliance on electricity for lighting and heating systems could also provide a benefit.
Migration et plurilinguisme: Parler en langues dans les Églises africaines en Europe
Authors: Fancello Sandra
Published: September 2009

Les enjeux liés aux pratiques langagières dans les Églises africaines implantées en Europe sont étroitement liés au type de migration en présence. Le choix des langues liturgiques s’inscrit dans des stratégies de recommunautarisation des migrants en milieu urbain ou de conversion des Européens. L’attention portée aux histoires de vie et aux parcours de conversion vise à dégager les modes d’interaction sociale qui amènent ces migrants à être confrontés à l’usage de la langue française ou anglaise, une situation porteuse de tension avec leur langue d’origine. Dans un contexte plurilingue, le “parler en langues” peut se présenter comme une solution imaginaire aux contradictions de l’unité dans la diversité.