bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Characteristics of Hazelnut Allergy in an Adjuvant-Free Mouse Model
Authors: Gonipeta Babu , Parvataneni Sitaram , Paruchuri Pranati , Gangur Venu
Published: February 2010

Background: Clinically it is recognized that tree nut allergies such as hazelnut allergy are not usually outgrown. Specific mechanisms underlying the persistence of such food allergies are incompletely understood. Here we studied the natural history and the long-term immune and clinical characteristics of hazelnut allergy in an adjuvant-free mouse model. Methods: BALB/c mice were sensitized to hazelnut protein using a transdermal sensitization protocol that does not use adjuvant. After establishing sensitization, exposure to hazelnut was withdrawn for 3, 5 or 8 months. The fate of circulating IgE antibodies was monitored. Subsequently, mice were given booster exposures and examined for memory IgE antibody and spleen cell IL-4 responses. Clinical characteristics and hypothermia responses upon oral allergen challenge were studied. Results: Upon allergen withdrawal, circulating hazelnut-specific IgE antibody levels began to drop. Nevertheless, IgE responses once established remained at significantly high levels for up to 8 months (the last time point studied) despite withdrawal of allergen exposure. Memory IgE responses to booster exposures were robust after 3, 5 or 8 months of allergen withdrawal. Furthermore, significant clinical reactivity to oral hazelnut challenge, and hypothermia responses were demonstrable at each of these time points. Long-lasting spleen cell memory IL-4 responses to hazelnut were detectable in these mice explaining the mechanism of sustenance of IgE responses and clinical sensitization. Conclusions: Hazelnut allergy once established persists for long periods, despite withdrawal of allergen exposure, due to long-lasting, memory IgE and IL-4 responses.
Association of Antigen-Stimulated Release of Tumor Necrosis Factor-Alpha in Whole Blood with Response to Chemotherapy in Patients with Pulmonary Multidrug-Resistant Tuberculosis
Authors: Eum Seok-Yong , Lee Ye-Jin , Min Jin-Hong , Kwak Hyun-Kyung , Hong Min-Sun , Kong Ji-Hye , Hwang Soo-Hee , Park Seung-Kyu , LeBlanc Jason J. , Via Laura E. , Barry, III Clifton E. , Cho Sang-Nae
Published: February 2010

Background: We have previously reported that TNF-α levels correlate to total mycobacterial burden in tuberculosis (TB) patients. Objective: To characterize the dynamics of cytokine responses in TB patients during chemotherapy to identify potential surrogate markers for effective treatment. Methods: Following induction by culture filtrate proteins in whole blood, production patterns of TNF-α, IL-10, IFN-γ and IL-12 were measured in 23 non-multidrug-resistant (MDR)-TB and 16 MDR-TB patients and in 31 healthy controls. Rates of mycobacterial clearance from the sputum were then measured and compared. Results: Prior to the initiation of chemotherapy, TNF-α and IL-10 levels were significantly higher in TB patients than in healthy controls while IFN-γ and IL-12 levels were similar. During chemotherapy, the levels of all 4 cytokines increased. We evaluated these responses separately in patients that did and did not clear their sputum culture at 2 and 6 months. At 2 months, decreases in both IFN-γ and IL-12 correlated strongly with a successful early response, while after 6 months of therapy, when half (7/14) of MDR-TB patients were still sputum culture positive, downregulation of TNF-α was uniquely correlated with sputum conversion between the groups. Conclusion: Our findings suggest the possibility that the regulation of TNF-α production in whole blood may be a more specific indicator of sputum conversion at 6 months than IFN-γ, IL-12 or IL-10 in MDR-TB patients.
Inflammatory Caspases in Innate Immunity and Inflammation
Authors: Yazdi Amir S. , Guarda Greta , D’Ombrain Marthe C. , Drexler Stefan K.
Published: February 2010

Caspases are best known for their role in apoptosis. More recently, they have gained prominence as critical mediators of innate immune responses. The so-called ‘inflammatory caspases’ include human caspase-1, -4, -5 and -12 and murine caspase-1, -11 and -12. Of these, caspase-1 is best characterized and serves as the prototype for our understanding of the processing, activation and function of inflammatory caspases. Like their apoptotic counterparts, inflammatory caspases are produced as inactive zymogens and require activation to become proteolytically active. Caspase-1 is activated within the inflammasome, a large cytosolic protein complex that is induced by a growing number of endogenous, microbial, chemical or environmental stimuli. The importance of caspase-1 in initiating innate immune responses is demonstrated by its role in cleaving pro-IL-1β and pro-IL-18 to their biologically active forms. New functions have also been implicated, as these proteases and the mechanisms underlying their activation and regulation emerge as important mediators of human health and disease.
‘Heat and Destroy’: Bronchoscopic-Guided Therapy of Peripheral Lung Lesions
Authors: Eberhardt Ralf , Kahn Nicolas , Herth Felix J.F.
Published: February 2010

Although the treatment of choice for stage I lung cancer patients is surgery, a lot of patients have a high comorbidity and are medically inoperable. Bronchoscopy, as a central technique in diagnosing lung cancer, has the potency to apply endoscopic therapy to small lung lesions in a minimally invasive way in patients with high risk for surgery. Unfortunately, bronchoscopy cannot always reach lesions in the peripheral lung, in particular the smaller lesions. Therefore, new guidance techniques like virtual bronchoscopy and electromagnetic navigation are now available and instead of using the systems as a diagnostic tool, these techniques may provide an option for therapeutic interventions to inoperable lung tumor patients. With endoscopic fiducial marker placement for robotic radiosurgery and endoluminal high-dose brachytherapy, local radiotherapy of peripheral lung tumors becomes feasible, reducing radiotherapy-induced toxicity. Radiofrequency tissue ablation through the working channel of a flexible bronchoscope may be a chance of making a diagnosis and a curative treatment in one endoscopic session. However, technical improvements of the ablation probes are currently necessary to expand the sizes of ablated areas. Even though the technologies are very attractive and pilot data are extremely encouraging, more studies establishing selection criteria and best utility are needed.
Screening for Diabetic Retinopathy: A Comparative Trial of Photography and Scanning Laser Ophthalmoscopy
Authors: Wilson P.J. , Ellis J.D. , MacEwen C.J. , Ellingford A. , Talbot J. , Leese G.P.
Published: February 2010

Aims: To evaluate the sensitivity and specificity of wide-field scanning laser ophthalmoscopy (WSLO) in the detection of referable diabetic eye disease, and to compare its performance with digital retinal photography. Methods: Patients enrolled into the study underwent non-mydriatic WSLO imaging, then single- and dual-field mydriatic digital retinal photography, and examination with slit lamp biomicroscopy, the reference standard. Grading of retinopathy was performed in a masked fashion. Results: A total of 380 patients (759 eyes) were recruited to the study. Technical failure rates for dilated single-field retinal photography, dual-field retinal photography and undilated WSLO were 6.3, 5.8 and 10.8%, respectively (0.005 < p < 0.02 for photography vs. WSLO). The respective indices for screening sensitivity were 82.9, 82.9 and 83.6% (p > 0.2). Specificity was 92.1, 91.1 and 89.5%, respectively (p > 0.2). Conclusions: Sensitivity and specificity for WSLO were similar to retinal photography. The technical failure rate was greater for the WSLO used in this study.
Activating without Inhibiting: Left-edge Boundary Tones and Syntactic Processing
Authors: Roll Mikael , Horne Merle , Lindgren Magnus
Published: February 2010

Right-edge boundary tones have earlier been found to restrict syntactic processing by closing a clause for further integration of incoming words. The role of left-edge intonation, however, has received little attention to date. We show that Swedish left-edge boundary tones selectively facilitate the on-line processing of main clauses, the syntactic structure they are associated with. In spoken Swedish, main clauses are produced with a left-edge boundary tone, which is absent in subordinate clauses. Main and subordinate clauses are further distinguished syntactically by word order when containing sentence adverbs. The effects of tone and word order on the processing of embedded main, subordinate, and neutral clauses (lacking sentence adverbs) were measured using ERPs. A posterior P600 in embedded main clauses and a smaller P600 in subordinate clauses indicated that embedded clauses with sentence adverbs were structurally less expected than neutral clauses and thus were reanalyzed. The tone functioned as a cue for main clause word order, selectively reducing the P600 in embedded main clauses, without affecting the processing of subordinate or neutral clauses. Its perception was reflected in a right frontal P200 effect. The left-edge boundary tone thus seems to activate a main clause structure, albeit without suppressing alternative structures. The P600 was also preceded by a short positive effect in cases where a left-edge boundary tone was absent.
Accessing Semantic Person Knowledge: Temporal Dynamics of Nonstrategic Categorical and Associative Priming
Authors: Wiese Holger , Schweinberger Stefan R.
Published: February 2010

Recent theories of semantic memory suggest a subdivision into several separate domains of knowledge. The present study examined the structure of semantic person knowledge by analyzing both behavioral and ERP correlates of associative priming (via co-occurrence and/or shared semantic information) versus purely categorical priming (via shared occupational information). Participants performed familiarity decisions for target faces, which were preceded by sandwich-masked prime names at either short (33 msec) or long (1033 msec) SOAs. Although masking effectively prevented explicit prime recognition, faster RTs were generally observed for both associative and categorical priming (relative to an unrelated prime-target condition). At the short SOA, both associatively and categorically primed targets similarly elicited more positive going ERPs compared with unrelated targets in the N400 time range (N400 priming effect), suggesting a common initial mechanism mediating both forms of priming. By contrast, at the long SOA, a typical N400 priming effect was observed for associative priming only, whereas the corresponding effect for categorical priming was small and restricted to a left parietal site. This hitherto unreported interaction of relatedness, and SOA in the N400 suggests an initial fast spreading of activation to a wide range of related targets, which subsequently focuses to more closely related people at longer SOAs. This ability of ERPs to trace the neural dynamics of activation for different forms of prime/target relatedness can be exploited for testing different models of semantic priming.
From Perception to Recognition Memory: Time Course and Lateralization of Neural Substrates of Word and Abstract Picture Processing
Authors: Maillard Louis , Barbeau Emmanuel J. , Baumann Cedric , Koessler Laurent , Bénar Christian , Chauvel Patrick , Liégeois-Chauvel Catherine
Published: February 2010

Through study of clinical cases with brain lesions as well as neuroimaging studies of cognitive processing of words and pictures, it has been established that material-specific hemispheric specialization exists. It remains however unclear whether such specialization holds true for all processes involved in complex tasks, such as recognition memory. To investigate neural signatures of transition from perception to recognition, according to type of material (words or abstract pictures), high-resolution scalp ERPs were recorded in adult humans engaged either in categorization or in memory recognition tasks within the same experimental setup. Several steps in the process from perception to recognition were identified. Source localization showed that the early stage of perception processing (N170) takes place in the fusiform gyrus and is lateralized according to the nature of stimuli (left side for words and right side for pictures). Late stages of processing (N400/P600) corresponding to recognition are material independent and involve anterior medial-temporal and ventral prefrontal structures bilaterally. A crucial transitional process between perception (N170) and recognition (N400/P600) is reflected by the N270, an often overlooked component, which occurs in anterior rhinal cortices and shows material-specific hemispheric lateralization.
Attentional Control in Anterior Cingulate Cortex Based on Probabilistic Cueing
Authors: Aarts Esther , Roelofs Ardi
Published: February 2010

In Stroop-like tasks, conflict effects in behavioral measures and ACC activity are smaller on trials following an incongruent trial than following a congruent one. Researchers have found no agreement on whether these sequential effects in ACC can be driven by experienced incongruency only or also by expectations about target types. In the present fMRI experiment, we specifically manipulated the expectancies by using symbolic cues predicting with 75% or 50% certainty the incongruent or congruent targets in a Stroop-like task. Both behavioral and dorsal ACC data replicated previous sequential effects, with conflict effects being smallest for targets following the cues that predicted with 75% certainty the incongruent targets. However, these effects were not driven by experienced conflict but by symbolic cues. These results demonstrate differential attentional control activity in ACC after probabilistic cueing, providing evidence for control adjustments driven by changes in expectation.
Neural Correlates of Sequence Learning with Stochastic Feedback
Authors: Averbeck Bruno B. , Kilner James , Frith Christopher D.
Published: February 2010

Although much is known about decision making under uncertainty when only a single step is required in the decision process, less is known about sequential decision making. We carried out a stochastic sequence learning task in which subjects had to use noisy feedback to learn sequences of button presses. We compared flat and hierarchical behavioral models and found that although both models predicted the choices of the group of subjects equally well, only the hierarchical model correlated significantly with learning-related changes in the magneto-encephalographic response. The significant modulations in the magneto-encephalographic signal occurred 83 msec before button press and 67 msec after button press. We also localized the sources of these effects and found that the early effect localized to the insula, whereas the late effect localized to the premotor cortex.
Auditory Target Detection Is Affected by Implicit Temporal and Spatial Expectations
Authors: Rimmele Johanna , Jolsvai Hajnal , Sussman Elyse
Published: February 2010

Mechanisms of implicit spatial and temporal orienting were investigated by using a moving auditory stimulus. Expectations were set up implicitly, using the information inherent in the movement of a sound, directing attention to a specific moment in time with respect to a specific location. There were four conditions of expectation: temporal and spatial expectation; temporal expectation only; spatial expectation only; and no expectation. Event-related brain potentials were recorded while participants performed a go/no-go task, set up by anticipation of the reappearance of a target tone through a white noise band. Results showed that (1) temporal expectations alone speeded reaction time and increased response accuracy; and (2) implicit temporal expectations alone independently enhanced target detection at early processing stages, prior to motor response. This was reflected at stages of perceptual analysis, indexed by P1 and N1 components, as well as in task-related stages indexed by N2; and (3) spatial expectations had an effect at later response-related processing stages but only in combination with temporal expectations, indexed by the P3 component. Thus, the results, in addition to indicating a primary role for temporal orienting in audition, suggest that multiple mechanisms of attention interact in different phases of auditory target detection. Our results are consistent with the view from vision research that spatial and temporal attentional control is based on the activity of partly overlapping, and partly functionally specialized neural networks.
Slow Fluctuations in Attentional Control of Sensory Cortex
Authors: Kam Julia W. Y. , Dao Elizabeth , Farley James , Fitzpatrick Kevin , Smallwood Jonathan , Schooler Jonathan W. , Handy Todd C.
Published: February 2010

Top–down control of visual sensory cortex has long been tied to the orienting of visual spatial attention on a rapid, moment-to-moment basis. Here, we examined whether sensory responses in visual cortex are also modulated by natural and comparatively slower fluctuations in whether or not one is paying attention to the task at hand. Participants performed a simple visual discrimination task at fixation as the ERPs to task-irrelevant probes in the upper visual periphery were recorded. At random intervals, participants were stopped and asked to report on their attentional state at the time of stoppage—either “on-task” or “off-task.” ERPs to the probes immediately preceding these subjective reports were then examined as a function of whether attention was in an on-task versus off-task state. We found that sensory-evoked responses to the probes were significantly attenuated during off-task relative to on-task states, as measured by the visual P1 ERP component. In two additional experiments, we replicated this effect while (1) finding that off-task sensory attenuation extends to the auditory domain, as measured by the auditory N1 ERP component, and (2) eliminating state-dependent shifts in general arousal as a possible explanation for the effects. Collectively, our findings suggest that sensory gain control in cortex is yoked to the natural ebb and flow in how much attention we pay to the current task over time.
Time-dependent Neural Processing of Auditory Feedback during Voice Pitch Error Detection
Authors: Behroozmand Roozbeh , Liu Hanjun , Larson Charles R.
Published: February 2010

The neural responses to sensory consequences of a self-produced motor act are suppressed compared with those in response to a similar but externally generated stimulus. Previous studies in the somatosensory and auditory systems have shown that the motor-induced suppression of the sensory mechanisms is sensitive to delays between the motor act and the onset of the stimulus. The present study investigated time-dependent neural processing of auditory feedback in response to self-produced vocalizations. ERPs were recorded in response to normal and pitch-shifted voice auditory feedback during active vocalization and passive listening to the playback of the same vocalizations. The pitch-shifted stimulus was delivered to the subjects' auditory feedback after a randomly chosen time delay between the vocal onset and the stimulus presentation. Results showed that the neural responses to delayed feedback perturbations were significantly larger than those in response to the pitch-shifted stimulus occurring at vocal onset. Active vocalization was shown to enhance neural responsiveness to feedback alterations only for nonzero delays compared with passive listening to the playback. These findings indicated that the neural mechanisms of auditory feedback processing are sensitive to timing between the vocal motor commands and the incoming auditory feedback. Time-dependent neural processing of auditory feedback may be an important feature of the audio-vocal integration system that helps to improve the feedback-based monitoring and control of voice structure through vocal error detection and correction.
Failure to Engage Spatial Working Memory Contributes to Age-related Declines in Visuomotor Learning
Authors: Anguera Joaquin A. , Reuter-Lorenz Patricia A. , Willingham Daniel T. , Seidler Rachael D.
Published: February 2010

It is well documented that both cognitive and motor learning abilities decline with normative aging. Given that cognitive processes such as working memory are engaged during the early stages of motor learning [Anguera, J., Reuter-Lorenz, P., Willingham, D., & Seidler, R. Contributions of spatial working memory to visuomotor learning. Journal of Cognitive Neuroscience, 22(9), 1917–1930, 2010], age-related declines in motor learning may be due in part to reductions in cognitive ability. The present study examined whether age-related declines in spatial working memory (SWM) contribute to deficits in visuomotor adaptation. Young and older adult participants performed a visuomotor adaptation task that involved adapting manual aiming movements to a 30° rotation of the visual feedback display as well as an SWM task in an fMRI scanner. Young adults showed a steeper learning curve than older adults during the early adaptation period. The rate of early adaptation was correlated with SWM performance for the young, but not older, adults. Both groups showed similar brain activation patterns for the SWM task, including engagement of the right dorsolateral prefrontal cortex and bilateral inferior parietal lobules. However, when the SWM activation was used as a limiting mask, younger adults showed neural activation that overlapped with the early adaptation period, whereas older adults did not. A partial correlation controlling for age revealed that the rate of early adaptation correlated with the amount of activation at the right dorsolateral prefrontal cortex. These findings suggest that a failure to effectively engage SWM processes during learning contributes to age-related deficits in visuomotor adaptation.
Parametric Manipulation of the Conflict Signal and Control-state Adaptation
Authors: Forster Sarah E. , Carter Cameron S. , Cohen Jonathan D. , Cho Raymond Y.
Published: February 2010

Mechanisms by which the brain monitors and modulates performance are an important focus of recent research. The conflict-monitoring hypothesis posits that the ACC detects conflict between competing response pathways which, in turn, signals for enhanced control. The N2, an ERP component that has been localized to ACC, has been observed after high conflict stimuli. As a candidate index of the conflict signal, the N2 would be expected to be sensitive to the degree of response conflict present, a factor that depends on both the features of external stimuli and the internal control state. In the present study, we sought to explore the relationship between N2 amplitude and these variables through use of a modified Eriksen flankers task in which target–distracter compatibility was parametrically varied. We hypothesized that greater target–distracter incompatibility would result in higher levels of response conflict, as indexed by both behavior and the N2 component. Consistent with this prediction, there were parametric degradations in behavioral performance and increases in N2 amplitudes with increasing incompatibility. Further, increasingly incompatible stimuli led to the predicted parametric increases in control on subsequent incompatible trials as evidenced by enhanced performance and reduced N2 amplitudes. These findings suggest that the N2 component and associated behavioral performance are finely sensitive to the degree of response conflict present and to the control adjustments that result from modulations in conflict.
The Dynamic Response of the Hurricane Wind Field to Spiral Rainband Heating
Authors: Moon Yumin , Nolan David S.
Published: February 2010

The response of the hurricane wind field to spiral rainband heating is examined by using a three-dimensional, nonhydrostatic, linear model of the vortex–anelastic equations. Diabatic heat sources, which are designed in accordance with previous observations of spiral rainbands, are made to rotate with the flow around the hurricane-like wind field of a balanced, axisymmetric vortex. Common kinematic features are recovered, such as the overturning secondary circulation, descending midlevel radial inflow, and cyclonically accelerated tangential flow on the radially outward side of spiral rainbands. Comparison of the responses to the purely convective and stratiform rainbands indicates that the overturning secondary circulation is mostly due to the convective part of the rainband and is stronger in the upwind region, while midlevel radial inflow descending to the surface is due to the stratiform characteristics of the rainband and is stronger in the downwind region. The secondary horizontal wind maximum is exhibited in both convective and stratiform parts of the rainband, but it tends to be stronger in the downwind region. The results indicate that the primary effects of rainbands on the hurricane wind field are caused by the direct response to diabatic heating in convection embedded in them and that the structure of the diabatic heating is primarily responsible for their unique kinematic structures. Sensitivity tests confirm the robustness of the results. In addition, the response of the hurricane wind field to the rainband heating is, in the linear limit, the sum of the asymmetric potential vorticity and symmetric transverse circulations.
CPOL Radar-Derived Drop Size Distribution Statistics of Stratiform and Convective Rain for Two Regimes in Darwin, Australia
Authors: Thurai M. , Bringi V. N. , May P. T.
Published: February 2010

This note builds on prior technique development related to the classification of rain types utilizing C-band polarimetric (CPOL) radar measurements. While the prior work was preliminary and limited in scope, the authors elaborate here on the basis of the drop size distribution (DSD)-based indexing technique for rain-type classification (convective/stratiform/mixed), and place it on firmer footing by testing the methodology against texture- and disdrometer-based methods as applied to Darwin datasets. A microphysical-based methodology is attractive as it links more directly to the underlying rainfall physical processes.

Statistics of the DSD parameters, namely, histograms of log10(Nw) and D0, for convective and stratiform rain types across the premonsoon buildup and monsoon regimes were derived and further separated for over land and over ocean regions. The maximum value for mean D0 (1.64 mm) and the largest histogram standard deviation (0.32 mm) occurred for convective rain over land during the buildup regime. The largest differences in D0 and NW histograms were found to be for convective rain between the buildup and monsoon regimes (independent of land or ocean areas). Stratiform rain histograms were found to be very similar during the buildup regime with little land–ocean differences. However, somewhat larger land–ocean differences were found for the monsoon stratiform rain. The main histogram characteristics of the “mixed” or “uncertain” rain type were closer to the convective rain type than to stratiform, across both regimes and land–ocean areas. Additionally, the Nw versus D0 cluster of points (mean ±1σ) for convective rain agrees very well with the previously published range of values for maritime convective (equilibrium-like) DSDs.
A Synergy Approach to Estimate Properties of Raindrop Size Distributions Using a Doppler Lidar and Cloud Radar
Authors: Träumner Katja , Handwerker Jan , Wieser Andreas , Grenzhäuser Jens
Published: February 2010

Remote sensing systems like radars and lidars are frequently used in atmospheric measurement campaigns. Because of their different wavelengths, they operate in different scattering regimes. Combined use may result in new measurement options. Here, an approach to estimate raindrop size distribution using vertical velocities measured by a lidar–radar combination is introduced and tested using a 2-μm Doppler lidar and a 35.5-GHz cloud radar. The lidar spectra are evaluated to deduce air motion from the aerosol peak and the fall velocity of the raindrops from the rain peak. The latter is weighted by the area (D2) of the scatters. The fall velocity derived from radar measurements is weighted by D6 (Rayleigh approximation). Assuming a size-dependent fall velocity and an analytical description of the drop size distribution, its parameters are calculated from these data. Comparison of the raindrop size distribution from the lidar–radar combination with in situ measurements on the ground yields satisfying results.
Lidar Scanning of Momentum Flux in and above the Atmospheric Surface Layer
Authors: Mann J. , Peña A. , Bingöl F. , Wagner R. , Courtney M. S.
Published: February 2010

Methods to measure the vertical flux of horizontal momentum using both continuous wave and pulsed Doppler lidar profilers are evaluated. The lidar measurements are compared to momentum flux observations performed with sonic anemometers over flat terrain at Høvsøre, Denmark, and profile-derived vertical momentum flux observations at the Horns Rev wind farm in the North Sea. Generally, the momentum fluxes are reduced because of the finite measuring volume of the instruments, and the filtering is crudely accounted for theoretically. The essential parameter for the estimation of the reduction is the ratio of the turbulence scale to the size of the measuring volume. For the continuous wave lidar the reduction can largely be compensated by averaging Doppler spectra instead of radial velocities.
Intercomparison of Bulk Microphysics Schemes in Model Simulations of Polar Lows
Authors: Wu Longtao , Petty Grant W.
Published: February 2010

Four spiraliform polar lows, two over the Sea of Japan and two over the Nordic Seas, were simulated with the Weather Research and Forecasting (WRF) model. Five mixed-phase bulk microphysics schemes (BMS) provided with WRF were run respectively in order to compare their performance in polar low simulations. The observed cloud-top temperatures (CTTs) were compared with the model simulations. Precipitation rates estimated by the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) and gauge-calibrated surface radar precipitation estimates around Japan were also used for validation. Although definitive validation is not possible with the available data, results from the WRF Single-Moment 6-class (WSM6) scheme appear to reproduce the cloud and precipitation processes most realistically. The model produced precipitation intensities comparable to validation products over the Sea of Japan. However, in the Nordic Seas cases, all five schemes produced significantly more precipitation than the AMSR-E estimates even though the latter estimates are known to average slightly high in the same region when validated against monthly totals measured at Jan Mayen Island (Norway).
Diagnosing the Origin of Extended-Range Forecast Errors
Authors: Jung T. , Miller M. J. , Palmer T. N.
Published: February 2010

Experiments with the ECMWF model are carried out to study the influence that a correct representation of the lower boundary conditions, the tropical atmosphere, and the Northern Hemisphere stratosphere would have on extended-range forecast skill of the extratropical Northern Hemisphere troposphere during boreal winter. Generation of forecast errors during the course of the integration is artificially reduced by relaxing the ECMWF model toward the 40-yr ECMWF Re-Analysis (ERA-40) in certain regions. Prescribing rather than persisting sea surface temperature and sea ice fields leads to a modest forecast error reduction in the extended range, especially over the North Pacific and North America; no beneficial influence is found in the medium range. Relaxation of the tropical troposphere leads to reduced extended-range forecast errors especially over the North Pacific, North America, and the North Atlantic. It is shown that a better representation of the Madden–Julian oscillation is of secondary importance for explaining the results of the tropical relaxation experiments. The influence from the tropical stratosphere is negligible. Relaxation of the Northern Hemisphere stratosphere leads to forecast error reduction primarily in high latitudes and over Europe. However, given the strong influence from the troposphere onto the Northern Hemisphere stratosphere it is argued that stratospherically forced experiments are very difficult to interpret in terms of their implications for extended-range predictability of the tropospheric flow. The results are discussed in the context of future forecasting system development.
Numerical Investigations on the Formation of Tropical Storm Debby during NAMMA-06
Authors: Chiao Sen , Jenkins Gregory S.
Published: February 2010

Mesoscale model forecasts were carried out beginning at 0000 UTC 19 August for simulating Tropical Disturbance 4, which was named Tropical Storm Debby on 22 August 2006. The Weather Research and Forecasting model, with 25-km grid spacing and an inner nested domain of 5-km grid spacing, was used. The development of a small closed vortex at approximately 0600 UTC 20 August 2006 at 850 hPa was found off the coast of Guinea in agreement with satellite images in the 5-km simulation. Intense convection offshore and over the Guinea Highlands during the morning of 20 August 2006 led to the production of a vortex formation by 1400 UTC at 700 hPa. Sensitivity tests show that the Guinea Highlands play an important role in modulating the impinging westerly flow, in which low-level flow deflections (i.e., northward turning) enhance the cyclonic circulation of the vortex formation. Yet, the moist air can be transported by the northward deflection flow from lower latitudes to support the development of mesoscale convective systems (MCSs). Although the model forecast is not perfect, it demonstrates the predictability of the formation and development of the tropical disturbance associated with the Guinea Highlands.
The Association of the Elevated Mixed Layer with Significant Severe Weather Events in the Northeastern United States*
Authors: Banacos Peter C. , Ekster Michael L.
Published: February 2010

The occurrence of rare but significant severe weather events associated with elevated mixed-layer (EML) air in the northeastern United States is investigated herein. A total of 447 convective event days with one or more significant severe weather report [where significant is defined as hail 2 in. (5.1 cm) in diameter or greater, a convective gust of 65 kt (33 m s−1) or greater, and/or a tornado of F2 or greater intensity] were identified from 1970 through 2006 during the warm season (1 May–30 September). Of these, 34 event days (7.6%) were associated with identifiable EML air in regional rawinsondes preceding the event. Taken with two other noteworthy events in 1953 and 1969, a total of 36 significant severe weather events associated with EML air were studied via composite and trajectory analysis. Though a small percentage of the total, these 36 events compose a noteworthy list of historically significant derechos and tornadic events to affect the northeastern United States. It is demonstrated that plumes of EML air emanating from the Intermountain West in subsiding, anticyclonically curved flows can reinforce the capping inversion and maintain the integrity of the EML across the central United States over a few days. The EML plume can ultimately become entrained into a moderately fast westerly to northwesterly midtropospheric flow allowing for the plume’s advection into the northeastern United States. Resultant thermodynamic conditions in the convective storm environment are similar to those more typically observed closer to the EML source region in the Great Plains of the United States. In addition to composite and trajectory analysis, two case studies are employed to demonstrate salient and evolutionary aspects of the EML in such events. A lapse rate tendency equation is explored to put EML advection in context with other processes affecting lapse rate.
U.S. Policy and the STEM Workforce System
Authors: Hira Ron
Published: February 2010

This article describes the science, technology, engineering, and mathematics (STEM) workforce system and discusses various policy mechanisms that can influence it. Discussion of STEM workforce policy too often focuses on controlling single variables, such as degree production, without taking into account how it influences, and is influenced by, other variables in the system. As a result, policy outcomes frequently fall short of goals. The policy discussion can be improved by taking an approach that recognizes that the STEM workforce is a system, with interconnectedness, feedback loops, and adaptation. This article sketches elements of that system and how data can help us understand relationships among them and highlights gaps in our knowledge. It also describes some of the policy mechanisms used to affect the workforce system and suggests steps policy makers can take to improve policy outcomes.
IT Offshoring and American Labor
Authors: Aspray William
Published: February 2010

This article presents an overview of the offshoring of information technology (IT), especially software and IT-enabled services, and its impacts on American labor. Topics include the history of offshoring politics in the United States, differences in attitudes between politicians and economists in their attitudes about the severity of the offshoring “problem,” national differences in types of offshoring providers, technological and other drivers of offshoring, reasons to offshore, characteristics of work amenable to offshoring, the employment impact in the United States, political and educational responses to offshoring in the United States, and the roles of labor unions and big business.
Expanding Entrepreneurship: Female and Foreign-Born Founders of New England Biotechnology Firms
Authors: McQuaid Jim , Smith-Doerr Laurel , Monti Daniel J.
Published: February 2010

Research on immigrant entrepreneurs in the United States has focused on small businesses in the retail and food service sectors rather than on high-technology start ups. Scholarship on women and immigrants in the U.S. science and technology workforce has focused on academia rather than scientists in industry. This article aims to bridge the gaps in these two literatures by examining the role of women and immigrants in founding science-based biotechnology firms. This research thus speaks to the sociological perspective on power inequalities for women and foreign-born people in entrepreneurship and in the U.S. science and technology workforce. Opportunities and barriers vary by organizational context, and the flexibility of the biotechnology industry has previously been found to benefit female scientists. But what of foreign-born scientists and women who play founding roles in biotech firms? A survey conducted of 261 biotechnology firms located in Massachusetts and New England in 2006 provides the data. The results show that 42% of the firms had at least one foreign-born founder, and 21% of firms had at least one female founder. These numbers suggest that foreign-born life scientists are well represented and female life scientists are somewhat underrepresented in founding roles in biotech. The role of entrepreneurs who have the double status of female immigrants is less clear and needs further study. The research finds significant variation in biotech entrepreneurship of immigrants by their world region of origin. Interviews supplement the survey data to illustrate the barriers and opportunities for foreign-born biotech entrepreneurs.
India-Born in the U.S. Science and Engineering Workforce
Authors: Varma Roli
Published: February 2010

With the intense debates over the extent to which foreign-born in the U.S. science and engineering (S&E) workplace displace U.S.-born, very few have focused on the work experience and professional activities of foreign-born in S&E. This article examines the extent to which India-born in the U.S. S&E workforce consider themselves professionally successful and/or facing institutional barriers, and their transnationalism between the United States and India. The article is primarily based on in-depth interviews conducted with different strata of scientists and engineers from India.
Preparation and Magnetic Properties of Cobalt Doping Mn-Zn Ferrite Nanoparticles
Authors: Youxian Zhang  , Yali Huang  , Jiaona Fan  , Xiaolong Fan  , Xueqin An
Published: February 2010

The Mn—Zn ferrite nanoparticles (CoxMn0.5Zn 0.5-xFe2O4, X = 0, 0.03, 0.12, 0.24, and 0.34) were prepared by a microemulsion technique and characterized by energy dispersive spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), etc. The XRD patterns indicate the presence of single-phase spinel ferrite in the samples. The particle size was estimated by the XRD method as well as from the micrograph taken by SEM. The magnetic properties of the samples were studied by VSM that showed superparamagnetic behaviors. Doping Co into the Mn—Zn ferrite can yield these superparamagnetic nanoparticles with narrow distribution of particle size so that their magnetic properties are improved.
Footprints in the Sand: British Colonial Counterinsurgency and the War in Iraq
Authors: Branch Daniel
Published: February 2010

Recent attempts to revive counterinsurgency strategies for use in Afghanistan and Iraq have been marked by a determination to learn lessons from history. Using the case of the campaign against the Mau Mau insurgency in Kenya of 1952—60, this article considers the reasons for this engagement with the past and the issues that have emerged as a consequence. The article disputes the lessons from British colonial history that have been learned by military planners, most obviously the characterization of nonmilitary forms of British counterinsurgency as nonviolent. Although it contests some of these supposed precedents for successful counterinsurgency in British military history, the article also identifies more generalizable elements of the Kenyan case. Particular emphasis is given to the effects on the nature of counterinsurgency, a reliance on locally recruited allies, and the decentralization of command.
Dirty Wars: Counterinsurgency in Vietnam and Today
Authors: Hunt David
Published: February 2010

Counterinsurgency doctrine emerged in the early 1960s as the Kennedy administration sought a politically progressive alternative to “pacification” campaigns waged by the French against the Vietnamese revolution. But its architects could not come up with a substitute for the conventional military reliance on massive firepower, which brought devastation to the Vietnamese people and failed to crush the “Viet Cong.” The Americans were again unsuccessful in transferring legitimacy to their allies in Saigon. After the war, the notion of counterinsurgency was kept alive among military writers. Rechristened as “COIN,” it has been given the task of providing cover for further “dirty wars” in Iraq and Afghanistan.
Counterinsurgency in El Salvador
Authors: Peceny Mark , Stanley William D.
Published: February 2010

Contemporary U.S. policy makers often characterize the U.S. counterinsurgency experience in El Salvador as a successful model to be followed in other contexts. This article argues that these characterizations significantly overstate the positive lessons of El Salvador, and ignore important cautionary implications. During the first part of the conflict, neither the Armed Forces of El Salvador (FAES) nor the U.S. followed the tenets of counterinsurgency doctrine. The FAES killed tens of thousands of non-combatants in 1979 and 1980, before the civil war even began. This repression may have preempted an incipient popular insurrection, but it also locked in a determined social base that enabled the armed left to build a highly effective and sustained insurgency. In 1984, the U.S. had to save the FAES from likely defeat through a major increase in military aid, especially airpower. When the Farabundo Martí National Liberation Front (FMLN) switched to a classical guerrilla strategy, the FAES, despite considerable U.S. aid, seldom followed best practices in counterinsurgency. Democratization and redistributional reforms were partial and flawed in implementation. The war settled into a stalemate that would likely have continued indefinitely had it not been for the collapse of the socialist bloc and significant changes in the interests of Salvadoran elites that were largely incidental to U.S. policies.The most important cautionary lesson is that indiscriminate violence against civilians early in a conflict can create dynamics that are very difficult to overcome in subsequent stages.
Effect of Staple Strength on Spinning Performance and Yarn Quality of Superfine Wools
Authors: Prins Martin W. , Pierlot Anthony P.
Published: February 2010

A processing trial was conducted at CSIRO comparing three batches of 17 µm, superfine fleece wool, collected from sale lot samples and matched for fiber properties but not staple strength. The three batches were compiled from auction display samples to have average staple strengths of 24, 32 and 43 N/ktex and were converted to top, yarn, and plain weave fabric. We demonstrate that, similar to previous research with mid-micrometer and fine wools sourced from commercial lots over a broad range of sources typically offered for auction and assembled as a consignment, staple strength has little influence on processing and product performance beyond top for superfine wool. We also compare our processing results to the predictive tools available to the industry (e.g. TEAM-3 and Yarnspec). The discounts applied to low staple strength raw wool should primarily be a reflection of commercial factors, for example supply and demand, rather than on objectively measured performance and technical attributes of the top and yarn. Economic benefits in topmaking may be possible through the selection and use of discounted, low staple strength wools with minimal impact on the technical attributes for yarn and fabric.
Pharmacokinetics, Pharmacodynamics, and Metabolism of Triethylenetetramine in Healthy Human Participants: An Open‐Label Trial
Authors: Lu Jun , Poppitt Sally D. , Othman Asma A. , Sunderland Tracey , Ruggiero Katya , Willett Michael S. , Diamond Lisa E. , Garcia Wilfredo D. , Roesch Benno G. , Cooper Garth J. S.
Published: February 2010

The selective CuII‐chelator, triethylenetetramine (TETA), is undergoing clinical trials for the treatment of heart failure in patients with diabetes. Recently, the authors showed that 2 acetylated metabolites, N1‐acetyltriethylenetetramine (MAT) and N1,N10‐diacetyltriethylenetetramine (DAT), are formed in humans following oral TETA administration. Thus, it became necessary to determine whether the N‐acetyltransferase (NAT) 2 phenotype has any effects on the pharmacological properties and safety profile of TETA. Twelve fast and 12 slow NAT2‐phenotype healthy participants were recruited. After oral drug administration, the authors collected plasma and urine samples, measured plasma concentrations of TETA and its 2 metabolites along with concomitant urinary copper concentrations, and performed safety tests. They present, for the first time, the complete 24‐hour pharmacokinetic profiles of TETA, MAT, and DAT in humans. There was no evidence for clear‐cut differences in pharmacokinetic profiles between fast and slow acetylators. Pharmacodynamic analysis showed no significant differences in cupruresis between the 2 NAT2 phenotypes. Safety results were consistent with TETA being well tolerated, and no significant differences in safety profiles were observed between the 2 phenotypes. Based on these data, NAT2 phenotype does not affect TETA's pharmacokinetic, pharmacodynamic, or safety profiles. TETA may be acetylated via an alternative mechanism, such as that catalyzed by spermidine/spermine N1‐acetyltranferase.