bluuebunny/crossref_metadata_2025 huggingface dataset:
Kinetic brain analysis and whole‐body imaging in monkey of [11C]MNPA: A dopamine agonist radioligand
Authors: Seneca Nicholas , Skinbjerg Mette , Zoghbi Sami S. , Liow Jeih‐San , Gladding Robert L. , Hong Jinsoo , Kannan Pavitra , Tuan Edward , Sibley David R. , Halldin Christer , Pike Victor W. , Innis Robert B.
Published: June 2008

With a view to future extension of the use of the agonist radioligand [11C]MNPA ([O‐methyl‐11C]2‐methoxy‐N‐propylnorapomorphine) from animals to humans, we performed two positron emission tomography (PET) studies in monkeys. First, we assessed the ability to quantify the brain uptake of [11C]MNPA with compartmental modeling. Second, we estimated the radiation exposure of [11C]MNPA to human subjects based on whole‐body imaging in monkeys. Brain PET scans were acquired for 90 min and included concurrent measurements of the plasma concentration of unchanged radioligand. Time‐activity data from striatum and cerebellum were quantified with two methods, a reference tissue model and distribution volume. Whole‐body PET scans were acquired for 120 min using four bed positions from head to mid thigh. Regions of interest were drawn on compressed planar whole‐body images to identify organs with the highest radiation exposures. After injection of [11C]MNPA, the highest concentration of radioactivity in brain was in striatum, with lowest levels in cerebellum. Distribution volume was well identified with a two‐tissue compartmental model and was quite stable from 60 to 90 min. Whole‐body PET scans showed the organ with the highest radiation burden (μSv/MBq) was the urinary bladder wall (26.0), followed by lungs (22.5), gallbladder wall (21.9), and heart wall (16.1). With a 2.4‐h voiding interval, the effective dose was 6.4 μSv/MBq (23.5 mrem/mCi). In conclusion, brain uptake of [11C]MNPA reflected the density of D2/3receptors, quantified relative to serial arterial measurements, and caused moderate to low radiation exposure. Synapse 62:700–708, 2008. Published 2008 Wiley‐Liss, Inc.
Oncoplastic Breast Surgery: A Global Perspective on Practice, Availability, and Training
Authors: Malycha Peter L. , Gough Ian R. , Margaritoni Marko , Deo S. V. S. , Sandelin Kerstin , Buccimazza Ines , Agarwal Gaurav
Published: June 2008

Oncoplastic surgery is the seamless joining of the extirpative and reconstructive aspects of breast surgery that is performed by a single surgeon. A symposium was held at ISW 2007 in Montreal with a prearranged aim to publish an article on the current and historical record of the developing specialty of oncoplastic breast surgery. The presenters and authors are well‐known breast surgeons from Australia, Croatia, India, Sweden, and South Africa.
Graduate Education in General Surgery and Its Related Specialties and Subspecialties in the United States
Authors: Bell Richard H.
Published: June 2008

Each year, approximately 1,000 graduating medical students enter training in general surgery and its related specialties and subspecialties in the United States. Traditionally, residents who want to practice vascular surgery, plastic surgery, thoracic surgery, and other specialties and subspecialties derived from general surgery have been required to complete five years of training in general surgery before embarking on further training. However, three phenomena have recently emerged that are changing the picture of surgical training: (1) proliferation of fellowships in subspecialties of general surgery, (2) increasing desire of subspecialties of general surgery for recognition as specialties in their own right, and (3) pressure to reduce or eliminate the traditional general surgery training required before specialization or subspecialization. In the meantime, and perhaps as a consequence of these changes, traditional general surgery has become less attractive as a specialty and there has been significant concern about the quality of training in general surgery. As a result of fewer trainees electing general surgery as a career, there is now increasing evidence of a shortage of surgeons who are able to handle a reasonably broad caseload of emergency care in general surgery and trauma.

Many of these issues are currently being addressed by the profession. Among the initiatives underway are developing a standardized curriculum in general surgery, appropriately apportioning operative experience between residency and fellowship, considering alternative pathways for training in subspecialties, and developing a system for oversight of advanced surgical training fellowships. The system for governance of graduate surgical education in the United States is less centralized than in other countries. One initiative that has been undertaken to improve coordination of efforts between educational and regulatory bodies is the formation of the Surgical Council on Resident Education (SCORE), a voluntary consortium of six organizations with the mission of defining a national curriculum for general surgery residency and with the goal of facilitating collaboration on educational issues involving general surgery and its related specialties and subspecialties.
Family History of Pancreatic Cancer in a High‐Risk Cancer Clinic: Implications for Risk Assessment
Authors: Hall Michael J. , Dignam James J. , Olopade Olufunmilayo I.
Published: June 2008

Detailed family history is a critical element of cancer risk assessment. The relative importance of pancreatic cancer (PC) in a close family member, particularly in hereditary breast‐ovarian syndrome (HBOS), is not clearly defined. We use a case‐control design to investigate the importance of a family history of PC to cancer risk assessment. Case and control families were identified from the University of Chicago Cancer Risk database (1994–2005). Pedigrees were analyzed for personal and familial clinical cancer data. Cases included all new subjects (probands) reporting a close relative (first or second degree) with PC. Controls included the probands enrolled in the database immediately prior to and subsequent to each case (i.e. two controls for each case). From 1,231 pedigrees, 103 PC were reported by the proband in 87 unique families. Many probands reported multiple or early‐onset PCs: one third (28/87) of case families met criteria for a familial PC syndrome [≥2 first‐degree relatives with PC (n = 10) or PC diagnosed ≤50 (n = 18)]. Of these families, the majority (75%) concurrently met criteria suggestive of hereditary breast‐ovarian syndrome (HBOS). Because of a family history consistent with HBOS, at least one individual from each of 29 case and 55 control families underwent genetic testing for BRCA1/2. Among case families, 19 of 29 (66%) had a BRCA1/2 mutation compared with 16 of 55 (29%) controls. A significant association between family history of PC and a BRCA1/2 mutation was seen (OR 3.78, 1.32–10.9). This point estimate was strengthened but less precise in the non‐Ashkenazi Jewish subset of tested families (OR 6.03, 1.68–22.14). In a high‐risk population, a family history of PC, though infrequently reported, is nonetheless clinically meaningful. In risk assessment for HBOS, identifying a family history of PC should strongly raise the suspicion of an unrecognized BRCA1/2 mutation.
The ‘M2 DASH’—Manchester-Modified Disabilities of Arm Shoulder and Hand Score
Authors: Khan Wasim S. , Jain Rohit , Dillon Bernice , Clarke Lawrence , Fehily Max , Ravenscroft Mark
Published: June 2008

The Disability of the Arm, Shoulder, and Hand (DASH) questionnaire was originally designed as a measure of disability in patients with disorders of the upper limb, but the DASH score is also affected by disability because of lower limb disorders. The aim of this study was to investigate the construct validity of the DASH questionnaire and to create a revised DASH questionnaire, the Manchester-modified or M2 DASH, with fewer questions that is more specific to the upper limb. Patients were asked to fill in the DASH questionnaire in a fracture clinic after ethical approval. This included 79 patients with upper limb injuries, 61 patients with lower limb injuries, and 52 control subjects. The mean DASH scores for the three groups varied significantly, and the lower limb group had a mean score of 16. The M2 DASH questionnaire was developed using questions more specific to the upper limb and included questions 1–4, 6, 13–17, 21–23, and 26–30 from the original questionnaire. The mean M2 DASH score for the lower limb group was 9 and, unlike the original DASH score, was not statistically different from the control group. The M2 DASH scores were then calculated for the upper limb group and a correlation study showed highly significant correlation between the original DASH scores and the M2 DASH scores. Our study shows that the original DASH questionnaire is not specific for the upper limb. The M2 DASH questionnaire has the advantage of being more specific for the upper limb than the DASH questionnaire, and it correlates well with the original DASH questionnaire when looking at isolated upper limb injuries.
Standard of Care for Hand Trauma: Where Should We Be Going?
Authors: Labs J. Daniel
Published: June 2008

Emergency Medical Treatment and Active Labor Act, an unfunded mandate for emergency hospital physician coverage, combined with falling reimbursement and escalating medico-legal risk, has resulted in declining enthusiasm for specialty coverage to emergency rooms. In a South West Florida community of 150,000, limited hand surgeons necessitated modification of acute on-call duties for hand trauma, whereby the hospital emergency room personnel performed evaluation and wound management with telephonic consultation followed by referral and definitive care in the outpatient setting by the hand surgeon. The policy for hand care, triage, management, and transfer is reviewed, as well as the first year experience with this highly efficient management methodology for urgent and emergent hand problems. In establishing a county-wide standard of care, emergency rooms and hand surgeons are coordinated to deliver excellent care by treatment protocol.
Effect of Surfactants and Temperature on Adsorption Behavior of Metal Ions on Organic–Inorganic Hybrid Exchanger, Acrylamide Aluminum Tungstate
Authors: Nabi Syed Ashfaq , Ganai Sajad Ahmad , Khan Amjad Mumtaz
Published: June 2008

The adsorption behavior of a thermally and chemically stable hybrid ion‐exchange material, acrylamide aluminum tungstate was explored in cationic (CTAB) and anionic (SDS) surfactants and acidic solvents. Critical micellar concentration (CMC) appears to be an important parameter in determining the adsorption behavior of metal ions. Equilibration time and temperature studies on the distribution coefficient of metal ions were studied. On the basis of the distribution coefficient, this material was successfully used for quantitative separations of some binary synthetic mixtures of metal ions by the column method. Hg(II) ion was selectively determined quantitatively in synthetic mixture. The material appears to be promising for separating toxic metal ions in a real matrix (industrial effluents and waste water) and can be utilized as a packing material in HPLC and GC columns for faster and more efficient separation.
Regulation of the human tRNase ZS gene expression
Authors: Takahashi Masayuki , Takaku Hiroaki , Nashimoto Masayuki
Published: June 2008

There are two types of tRNA 3′ processing endoribonucleases (tRNase Z): a short form (tRNase ZS) and a long form (tRNase ZL). Although the human genome contains both genes, little is known about the physiological role of tRNase ZS. We found that the human tRNase ZS gene expression appears to be post‐transcriptionally regulated. Additionally, analyses for cis‐regulatory elements for the tRNase ZS gene transcription suggested that transcription factors that bind to five different sites on the promoter work together to potentiate the transcription initiation. Furthermore, we found that tRNase ZS is predominantly present in the cytosol and hardly in the nucleus.
Self‐recognition by an intrinsically disordered protein
Authors: Hecht Oliver , Ridley Helen , Boetzel Ruth , Lewin Allison , Cull Nick , Chalton David A. , Lakey Jeremy H. , Moore Geoffrey R.
Published: June 2008

The intrinsically disordered translocation domain (T‐domain) of the protein antibiotic colicin N binds to periplasmic receptors of target Escherichia coli cells in order to penetrate their inner membranes. We report here that the specific 27 consecutive residues of the T‐domain of colicin N known to bind to the helper protein TolA in target cells also interacts intramolecularly with folded regions of colicin N. We suggest that this specific self‐recognition helps intrinsically disordered domains to bury their hydrophobic recognition motifs and protect them against degradation, showing that an impaired self‐recognition leads to increased protease susceptibility.
Reproductive biology of the Patagonian bobtail squid, Semirossia patagonica (Sepiolidae: Rossiinae) in the south-west Atlantic
Authors: Önsoy Bahadir , Laptikhovsky Vladimir , Salman Alp
Published: June 2008

A total of 104 Semirossia patagonica were collected all over the Patagonian shelf between the depths of 47 and 295 m. Mature female size varied from 10 to 35 mm ML, mature male size was 16–32 mm. Potential fecundity ranged between 527–766 eggs in pre-spawning females, ripe egg size was 3.4–5.0 mm. The oviduct capacity probably was no more than 30 eggs. The maximum number of spermatophores in males was 229. Males transfer 2–19 spermatophores to females during copulation. The ovulation pattern is asynchronous, individual spawning is continuous. Reproduction occurs all year round. Semirossia patagonica is a south-west Atlantic ecological sibling of north-east Atlantic bobtail squids Sepiola spp. and Sepietta spp.
A new method to determine the reproductive condition in female tubeworms tested inSeepiophila jonesi(Polychaeta: Siboglinidae: Vestimentifera)
Authors: Hilário Ana , Tyler Paul A. , Pond David W.
Published: June 2008

Vestimentiferan tubeworms are significant members of deep-sea chemosynthetically-driven communities, including hydrothermal vents and cold seeps. The reproductive condition in this taxon is rarely studied because of sampling constraints inherent to these environments, and the lack of a simple methodology to quantify gonad development in vestimentiferans.

We demonstrate that the amount of gonad found in the first 10 mm of trunk can be used as representative of the reproductive condition of the individual, and we establish a linear relationship between the amount of gonad and the proportion of wax ester in the trunk of female vestimentiferans. This relationship represents a new method for the determination of the reproductive condition in this group.
Seasonal reproductive activity in the pterobranch hemichordate Rhabdopleura compacta
Authors: Sato Atsuko
Published: June 2008

Pterobranchs are small marine filter feeders in the phylum Hemichordata. Their phylogenetic position and anatomical structure has resulted in pterobranchs featuring in many scenarios concerning the evolution of chordates. Despite this interest, the basic reproductive biology of pterobranchs is still poorly known. To address this issue, the reproductive season of Rhabdopleura compacta was investigated by collecting specimens in 2004–2007 from a population growing on disarticulated bivalve shells off the south coast of Devon, UK. I analysed reproductive status by categorizing shells according to the condition of the colonies growing on them. The frequency of shells having mature females was almost constant from spring to autumn among shells with active colonies. However, it was apparent that: (a) shells having mature females were more likely to be incubating embryos or larvae in June and July than other months; and (b) the production of embryos was high in June, and then decreased by July. Thus, despite the previous speculation that the species is capable of successful sexual reproduction throughout the year, the present study shows seasonality in reproduction of R. compacta, with at least a peak season during summer.
Reproductive behaviour and cross-mating of two closely related pygmy squids Idiosepius biserialis and Idiosepius thailandicus (Cephalopoda: Idiosepiidae)
Authors: Nabhitabhata Jaruwat , Suwanamala Jitima
Published: June 2008

Idiosepius biserialis and Idiosepius thailandicus have been previously described as separate species although the difference in morphological characters is only the arrangement of pegs in tentacular-club suckers. The former species inhabits sea grass beds in the Andaman Sea of Thailand. The latter species inhabits mangroves in the eastern Gulf of Thailand. The present study of reproductive behaviour, mating, and spawning of the two species in captivity demonstrated that they are closely related. Copulation was performed using tentacles by the male for fixation of spermatophores at the buccal region of the female. Behavioural patterns were distinguished based on the hovering and adhering positions of each sex. Cross-mating between two species was initiated and observed, yielding fertilized eggs which developed to the organogenesis stage. Reproductive behaviour of crossed pairs was similar to those of individual species. This study revealed that the two ‘species’ are not reproductively isolated.
Predation by the sea urchin Strongylocentrotus droebachiensis on capsular egg masses of the whelk Buccinum undatum
Authors: Dumont Clement P. , Roy Jean-Sebastien , Himmelman John H.
Published: June 2008

We evaluated sea urchin Strongylocentrotus droebachiensis predation on egg masses of the whelk Buccinum undatum. The urchin actively grazes on the egg masses, even as they are being deposited on the bottom. Whelks preferentially lay their egg masses on vertical areas where urchin densities are 4-fold less than on flat areas. This strategy is advantageous, as experimental trials showed that the loss in the mass of capsules was 4 fewer on walls than on flat areas. Nevertheless, a high proportion of egg masses on walls show damage from predation. Urchins provided with egg masses in the laboratory, ingested the capsules at a steady rate over a 9-d period (5 urchins ingested 2.8 g.d-1). Urchins provided agar discs that included a preferred alga and whelk capsule walls ingested the discs at a rate that was half that observed for discs that only included the alga. Discs that included the preferred alga and capsule contents were eaten at the same rate as discs that only included the alga. Thus, capsule walls, but not the capsule contents, provide a defence against urchin predation. Laying aggregate egg masses likely provides only a limited advantage, as the attachment surface does not increase with the number of egg masses deposited together, so the risk of detachment increases. Consideration of the interactions between urchins and whelks is important in managing the fisheries of the two species.
Multiple spawning and length of embryonic development ofMunida gregariain northern Patagonia (Argentina)
Authors: Dellatorre Fernando G. , Barón Pedro J.
Published: June 2008

Munida gregariais a small galatheid widely distributed around the southern hemisphere, considered a key species in food webs of coastal and shelf marine ecosystems. Previous studies conducted at 55°S and 46°S on the Atlantic coast of South America, have shown that the species can adapt its reproductive patterns to different environmental conditions. The objectives of this work are to complete this analysis by determining: (1) the reproductive season span; (2) the potential of the species to produce multiple clutches of eggs; (3) the length of its embryonic development; and (4) based on previous objectives, the potential number of clutches produced byM. gregariaby reproductive season in the northern range of its coastal distribution (42–43°S, northern Patagonia). In this region, brooding females were present from June to December, representing more than 80% of total females between July and October. Females presented previtellogenic oocytes beginning maturation just after egg extrusion, and fully developed vitellogenic oocytes just before hatching. From November to February increasing proportions of females showed signs of athresia and resorption of mature oocytes. The complete embryonic development ofM. gregarialasted 26–29 days at 11ºC constant temperature. Considering the pattern of synchronous ovary re-maturation and embryonic development, the length of embryogenesis at water temperatures typical from costal waters off northern Patagonia during the breeding season, it is concluded that femaleM. gregariahave the potential to consecutively lay more than three egg clutches per reproductive season.
A new species ofTrypanosyllis(Polychaeta: Syllidae) from Brazil, with a redescription of Brazilian material ofTrypanosyllis zebra
Authors: De Matos Nogueira João Miguel , Fukuda Marcelo Veronesi
Published: June 2008

A new species ofTrypanosylliswas found in a collection of polychaetes living on algae, sponges, ascidians and sabelariid reefs at the intertidal zone of a rocky shore, at Praia do Guaraú, south-eastern Brazil.Trypanosyllis aurantiacussp. nov., is characterized by having an orange body in life, with dark red antennae and cirri throughout, falcigers with short, sub-bidentate blades, and parapodia with thick, distally sharp, protruding aciculae, two to three aciculae on each anterior parapodium, two aciculae on midbody segments, single acicula per parapodium on posteriormost chaetigers.Trypanosyllis aurantiacussp. nov., is compared with the most similar congeners and a redescription ofTrypanosyllis zebra, based on Brazilian specimens collected from similar environments at nearby beaches, is given.
Valuing lives and life years: anomalies, implications, and an alternative
Authors: DOLAN PAUL , METCALFE ROBERT , MUNRO VICKI , CHRISTENSEN MICHAEL C.
Published: June 2008

Many government interventions seek to reduce the risk of death. The value of preventing a fatality (VPF) is the monetary amount associated with each statistical death that an intervention can be expected to prevent. The VPF has been estimated using a preference-based approach, either by observing market behaviour (revealed preferences) or by asking hypothetical questions that seek to replicate the market (stated preferences). The VPF has been shown to differ across and within these methods. In theory, the VPF should vary according to factors such as baseline and background risk, but, in practice, the estimates vary more by theoretically irrelevant factors, such as the starting point in stated preference studies. This variation makes it difficult to choose one unique VPF. The theoretically irrelevant factors also affect the estimates of the monetary value of a statistical life year and the value of a quality-adjusted life year. In light of such problems, it may be fruitful to focus more research efforts on generating the VPF using an approach based on the subjective well-being associated with different states of the world.
Anisotropic shear‐wave velocity structure of the Earth's mantle: A global model
Authors: Kustowski B. , Ekström G. , Dziewoński A. M.
Published: June 2008

We combine a new, large data set of surface wave phase anomalies, long‐period waveforms, and body wave travel times to construct a three‐dimensional model of the anisotropic shear wave velocity in the Earth's mantle. Our modeling approach is improved and more comprehensive compared to our earlier studies and involves the development and implementation of a new spherically symmetric reference model, simultaneous inversion for velocity and anisotropy, as well as discontinuity topographies, and implementation of nonlinear crustal corrections for waveforms. A comparison of our new three‐dimensional model, S362ANI, with two other models derived from comparable data sets but using different techniques reveals persistent features: (1) strong, ∼200‐km‐thick, high‐velocity anomalies beneath cratons, likely representing the continental lithosphere, underlain by weaker, fast anomalies extending below 250 km, which may represent continental roots, (2) weak velocity heterogeneity between 250 and 400 km depths, (3) fast anomalies extending horizontally up to 2000–3000 km in the mantle transition zone beneath subduction zones, (4) lack of strong long‐wavelength heterogeneity below 650 km suggesting inhibiting character of the upper mantle–lower mantle boundary, and (5) slow‐velocity superplumes beneath the Pacific and Africa. The shear wave radial anisotropy is strongest at 120 km depth, in particular beneath the central Pacific. Lateral anisotropic variations appreciably improve the fit to data that are predominantly sensitive to the uppermost and lowermost mantle but not to the waveforms that control the transition zone and midmantle depths. Tradeoffs between lateral variations in velocity and anisotropy are negligible in the uppermost mantle but noticeable at the bottom of the mantle.
Hydrothermal activity and volcano distribution along the Mariana arc
Authors: Baker Edward T. , Embley Robert W. , Walker Sharon L. , Resing Joseph A. , Lupton John E. , Nakamura Ko‐ichi , de Ronde Cornel E. J. , Massoth Gary J.
Published: June 2008

Submarine volcanic arcs extend for fully a third of the length of the mid‐ocean ridge system, but systematic investigation of hydrothermal venting on those arcs is sparse. Here we report on the distribution of hydrothermal activity along the intraoceanic Mariana arc. We identify 76 volcanic edifices along 1370 km of arc, grouped into 60 “volcanic centers,” of which at least 26 (20 submarine) are hydrothermally or volcanically active. The overall volcanic center density is 4.4/100 km of arc, and that of active centers is 1.9/100 km. An equal length of the Tonga‐Kermadec arc holds fewer centers, 2.9/100 km, but a similar density of active centers, 1.8/100 km. The lower percentage of active centers on the Mariana arc results from its having both fewer caldera volcanoes, since on both arcs calderas are twice as likely as cones to be active, and a lower percentage of active calderas and cones. Active centers are found from 80 to 230 km above the subducting Pacific slab, and a quarter lie behind the arc front. The frequency distribution of center spacing along the arc front peaks between 20 and 30 km and shows the asymmetric, long‐tail shape typical for many other arcs, especially those with volcano populations >∼20. There is no evidence for a regular spacing of volcanic centers. Using the new Mariana data and recent data from the Tonga‐Kermadec arc, we estimate that all intraoceanic arcs combined may contribute hydrothermal emissions equal to ∼10% of that from the global mid‐ocean ridge.
Submarine groundwater discharge from the Yellow River Delta to the Bohai Sea, China
Authors: Taniguchi Makoto , Ishitobi Tomotoshi , Chen Jianyao , Onodera Shin‐ichi , Miyaoka Kunihide , Burnett William C. , Peterson Richard , Liu Guanqun , Fukushima Yoshihiro
Published: June 2008

Spatial and temporal variations of submarine groundwater discharge (SGD) have been evaluated by automated seepage meters from the Yellow River delta to 7 km offshore in the Bohai Sea, China. We identified three zones from the coast to offshore based on different relationships between tidal and SGD changes. Our results indicate that the point of maximum SGD shifted 2 km offshore from September 2004 to September 2006. This spatial change is thought to be caused by sediment deposition near the coast. Integrating submarine fresh groundwater discharge (SFGD) along the coastline of the Yellow River delta using measured values of SFGD per unit length of shoreline shows that discharge of fresh groundwater along the entire delta would be equivalent to 4.5 to 7.0 % of the river discharge.
A study of stratospheric chlorine partitioning based on new satellite measurements and modeling
Authors: Santee M. L. , MacKenzie I. A. , Manney G. L. , Chipperfield M. P. , Bernath P. F. , Walker K. A. , Boone C. D. , Froidevaux L. , Livesey N. J. , Waters J. W.
Published: June 2008

Two recent satellite instruments, the Microwave Limb Sounder (MLS) on Aura and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE‐FTS) on SCISAT‐1, provide an unparalleled opportunity to investigate stratospheric chlorine partitioning. We use measurements of ClO, HCl, ClONO2, and other species from MLS and ACE‐FTS to study the evolution of reactive and reservoir chlorine throughout the lower stratosphere during two Arctic and two Antarctic winters characterizing both relatively cold and relatively warm and disturbed conditions in each hemisphere. At middle latitudes, and at high latitudes at the beginning of winter, HCl greatly exceeds ClONO2, representing ∼0.7–0.8 of estimated total inorganic chlorine. Nearly complete chlorine activation is seen inside the winter polar vortices. In the Arctic, chlorine recovery follows different paths in the two winters: In 2004/2005, deactivation initially takes place through reformation of ClONO2, then both reservoirs are produced concurrently but ClONO2 continues to significantly exceed HCl, and finally slow repartitioning between ClONO2 and HCl occurs; in 2005/2006, HCl and ClONO2 rise at comparable rates in some regions. In the Antarctic, chlorine deactivation proceeds in a similar manner in both winters, with a rapid rise in HCl accompanying the decrease in ClO. The measurements are compared to customized runs of the SLIMCAT three‐dimensional chemical transport model. Measured and modeled values typically agree well outside the winter polar regions. In contrast, partly because of the equilibrium scheme used to parameterize polar stratospheric clouds, the model overestimates the magnitude, spatial extent, and duration of chlorine activation inside the polar vortices.
A regional climate modeling study of the effect of desert dust on the West African monsoon
Authors: Konare A. , Zakey A. S. , Solmon F. , Giorgi F. , Rauscher S. , Ibrah S. , Bi X.
Published: June 2008

We investigate the effect of the shortwave radiative forcing of Saharan dust on the West African monsoon with a regional climate model interactively coupled to a dust model. Toward this purpose we intercompare sets of 38 summer monsoon season simulations (1969–2006) with and without dust effects over a domain encompassing most of the African continent and adjacent regions. We find that the main effect of the dust radiative shortwave forcing is to reduce precipitation over the Sahel region. This is in response to cooling over the Sahara, which decreases the meridional gradient of moist static energy and results in a weakening of the monsoon energy pump. The dust effects also cause a strengthening of the southern branch of the African Easterly Jet and a weakening of Tropical Easterly Jet. Over the Sahel the dust forcing causes climate response patterns that are similar to those found during dry years over the Sahel, which suggests that Saharan dust feedbacks might have a role in maintaining drought events over the region. Overall, the inclusion of dust also tends to improve the model simulation of the West African monsoon, as well as African and Tropical Easterly jets. This work focuses on climatic feedback associated to shortwave radiation forcing and should be further completed by the study of dust effect on long‐wave radiation.
Environmental impact of atmospheric NH3 emissions under present and future conditions in the eastern United States
Authors: Pinder R. W. , Gilliland A. B. , Dennis R. L.
Published: June 2008

Recent regulations require large‐scale emission reductions of NOx and SO2 in the eastern United States. These emission changes will alter the partitioning of ammonia between the gas and particle phases. Furthermore, ammonia emissions are expected to increase in the future. How will these changes impact the contribution of ammonia to inorganic particulate matter and nitrogen deposition? We use a chemical transport model and emission scenarios representing years 2001, 2010, and 2020 to estimate the future change of the sensitivity of iPM2.5 to ammonia emission reductions and change in nitrogen deposition to ecosystems. We find that during winter conditions, particulate matter concentrations in several locations in the Midwestern US continue to have significant sensitivity to NH3 emissions. In addition, the total nitrogen deposition near NH3 emission sources increases 10–40%
Phase relations of Fe‐Si alloy up to core conditions: Implications for the Earth inner core
Authors: Asanuma Hidetoshi , Ohtani Eiji , Sakai Takeshi , Terasaki Hidenori , Kamada Seiji , Hirao Naohisa , Sata Nagayoshi , Ohishi Yasuo
Published: June 2008

X‐ray diffraction experiments were conducted to 257 GPa and high temperature in situ on an iron‐silicon alloy containing 3.4 wt% silicon, a candidate for the Earth's inner core forming material. The results revealed that fcc and hcp phases coexist up to 104 GPa. A single hcp phase is stable at higher pressures at least up to 3600 K at 242 GPa and to 2400 K at 257 GPa. Dissolution of silicon in the liquid outer core following reaction with the silicate mantle during core formation strongly suggests the existence of silicon in the solid inner core. Our results revealed that the iron‐3.4 wt% silicon alloy in the inner core is likely to possess an hcp structure, which can explain the inner core anisotropy observed in seismology.
Air‐sea interaction between tropical cyclone Nari and Kuroshio
Authors: Wu Chau‐Ron , Chang Yu‐Lin , Oey Lie‐Yauw , Chang C.‐W. June , Hsin Yi‐Chia
Published: June 2008

The air‐sea interaction between tropical cyclone Nari (Sep/6–16/2001) and Kuroshio is studied using satellite observations and an ocean model. Nari crossed the Kuroshio several times, which caused variations in typhoon intensity. Nari weakened when it was over the shelf north of Kuroshio where cooling took place due to mixing of the shallow thermocline. The cyclonic circulation penetrated much deeper for the slowly‐moving storm, regardless of Nari's intensity. Near‐inertial oscillations are simulated by the model in terms of the vertical displacement of isotherms. The SST cooling caused by upwelling and vertical mixing is effective in cooling the upper ocean several days after the storm had passed. At certain locations, surface chlorophyll‐a concentration increases significantly after Nari's departure. Upwelling and mixing bring nutrient‐rich subsurface water to the sea surface, causing enhancement of phytoplankton bloom.
Field survey and numerical simulation of the 21 November 2004 tsunami at Les Saintes (Lesser Antilles)
Authors: Le Friant Anne , Heinrich Philippe , Boudon Georges
Published: June 2008

Although a few historical tsunamis have occurred in the Lesser Antilles region, their characteristics are poorly documented due to the ephemeral nature of the associated signatures. Recently, a tsunami was generated following a magnitude Mw 6.3 earthquake that occurred on 21 November 2004 between Guadeloupe and Dominica. This was one of the two largest historical earthquakes recorded in this area in the last century. A field survey allowed us to characterize the tsunami which affected Les Saintes, the southern coast of Basse‐Terre (Guadeloupe) and northern Dominica. We used these data to constrain a numerical simulation of tsunami generation and propagation. The 21 November tsunami provides a unique opportunity to further constrain the models of brittle deformation in the back arc region proposed by previous tectonic investigations, to characterize the tsunami signatures and to improve regional hazards evaluation.
General aspects of a T213L256 middle atmosphere general circulation model
Authors: Watanabe Shingo , Kawatani Yoshio , Tomikawa Yoshihiro , Miyazaki Kazuyuki , Takahashi Masaaki , Sato Kaoru
Published: June 2008

A high‐resolution middle atmosphere general circulation model (GCM) developed for studying small‐scale atmospheric processes is presented, and the general features of the model are discussed. The GCM has T213 spectral horizontal resolution and 256 vertical levels extending from the surface to a height of 85 km with a uniform vertical spacing of 300 m. Gravity waves (GWs) are spontaneously generated by convection, topography, instability, and adjustment processes in the model, and the GCM reproduces realistic general circulation in the extratropical stratosphere and mesosphere. The oscillations similar to the stratopause semiannual oscillation and the quasi‐biennial oscillation (QBO) in the equatorial lower stratosphere are also spontaneously generated in the GCM, although the period of the QBO‐like oscillation is short (15 months). The relative roles of planetary waves, large‐scale GWs, and small‐scale GWs in maintenance of the meridional structures of the zonal wind jets in the middle atmosphere are evaluated by calculating Eliassen‐Palm diagnostics separately for each of these three groups of waves. Small‐scale GWs are found to cause deceleration of the wintertime polar night jet and the summertime easterly jet in the mesosphere, while extratropical planetary waves primarily cause deceleration of the polar night jet below a height of approximately 60 km. The meridional distribution and propagation of small‐scale GWs are shown to affect the shape of the upper part of mesospheric jets. The phase structures of orographic GWs over the South Andes and GWs emitted from the tropospheric jet stream are discussed as examples of realistic GWs reproduced by the T213L256 GCM.
Collaborative Teaching and Learning
Authors: Hagstrom Fran , McGehee Marilyn G. , Aslin Larry , Baker Kim
Published: June 2008

Based on pedagogical theory, this article describes how collaborative teaching was used in six first year undergraduate communication disorders classes in order to promote critical and self-reflective thinking. Junior level teaching faculty incorporated KASA standards and project-based learning that focused on diversity and research into cross-course projects over two semesters. The projects required collaborative work among students and among faculty. As a result, collaboration at both the instructor and student level contributed to the learning process and facilitated student construction of knowledge.
Service Learning 201: Beyond the Basics
Authors: Schoenbrodt Lisa
Published: June 2008

Service learning is not a new concept in the field of education or communication disorders, involving a partnership that is formed between a community agency and a university training program. For service learning to effective, equal “buy in” is needed from all parties involved. Service learning is a natural fit in the area of communication disorders because the types of agencies involved and the types of experiences dovetail with the range of disorders in the population. In one department of Speech Pathology, we offered a variety of service-learning courses to students in training throughout their undergraduate curriculum, with different commitments in terms of time to service. In the past, our introductory level coursework involved brief experiences that were woven into the coursework, but was not the intensity of time or commitment that is required in graduate courses. In addition, with this introductory class, I had to consider the level of the student with little to no background with individuals with disabilities. These factors led us to design a service-learning course that incorporated time directly spent with the community partner agency on site and time spent indirectly planning an activity for clients at the community center.
Collaborative Learning in the Speech-Language Pathology and Audiology Classroom
Authors: Potts Carolyn S. , Ginsberg Sarah M.
Published: June 2008

In recent years, colleges and universities across the country have been called upon to increase the quality of education provided and to improve student retention rates. In response to this challenge, many faculty are exploring alternatives to the traditional “lecture-centered” approach of higher education in an attempt to increase student learning and satisfaction. Collaborative learning is one method of teaching, which has been demonstrated to improve student learning outcomes.
Challenges for Higher Education: Teaching the Cognitive Social Bases of Language
Authors: Cloud Steven J. , Muma John R.
Published: June 2008

Professionals in higher education are perfectly situated to reshape the field of Human Communication Sciences and Disorders in accordance with many substantive advancements in the cognitive socialization literature. This article provides a four-level model of the cognitive social bases of language, and it includes a discussion of four substantive issues toward improved clinical services. The topics include (a) the modality and core aspects of language; (b) the centrality of intent; (c) the lack of construct validity of language tests; and (d) the heterogeneous nature of clinical populations.
Microwave variable waveguide attenuator
Authors: Fabeni P. , Mugnai D. , Pazzi G. P. , Ranfagni A.
Published: June 2008

A new type of cutoff attenuator is presented. The attenuator works in the X-band in conditions of almost perfect matching. This means that the phase of the wave, which propagates inside the guide, does not suffer sensible variation in the passage between X- and Ku-bands. Moreover, the attenuator works directly in the X-band, avoiding the passage between waveguide and cable, thus eliminating spurious effects due to this (double) passage. Experimental results of attenuation and dephasing using a prototype are also presented.
Effects of different colorants on morphological development of sheared isotactic polypropylene: A study using synchrotron wide-angle x-ray scattering
Authors: Zhu Peng-wei , Tung Jason , Edward Graham , Nichols Lance
Published: June 2008

Sheared isotactic polypropylene (iPP) forms a special crystalline assembly called branched shish kebab. The effects of two colorants, Cu-phthalocyanine and ultramarine blue, on the branched shish-kebab structure have been investigated by using synchrotron wide-angle x-ray scattering. The effects of the colorants on the morphological distributions of iPP are well constructed through the shear field or temperature gradient, including crystallinity, molecular orientation, fraction of lamellae, and thickness of crystalline lamellae. It is found that the Cu-phthalocyanine can significantly affect the morphological development of sheared iPP but the ultramarine blue cannot. In the presence of Cu-phthalocyanine, the degree of crystallinity is increased, the molecular orientation is enhanced, the more a∗-axis-oriented components form, and the crystalline lamellae are thickened.
Experimental evidence of internal solitary wave-induced global instability in shallow water benthic boundary layers
Authors: Carr M. , Davies P. A. , Shivaram P.
Published: June 2008

Experimental evidence is presented in support of the theoretical prediction of Diamessis and Redekopp [J. Phys. Oceanogr. 36, 784 (2006)] for wave-induced vortex shedding at the lower solid boundary of a stratified fluid system as a result of global instability. The time-dependent boundary layer induced by a strongly nonlinear internal wave of depression in shallow water is examined experimentally. Measurements of the velocity field close to the bottom boundary illustrate coherent periodic shedding of vortex structures at the lower boundary in the adverse pressure gradient region aft of the wave. The vortical structures ascend high into the water column and cause significant benthic turbulence. It is shown that global instability has a critical threshold dependent on the Reynolds number of the flow and the amplitude of the wave. The critical amplitudes observed are approximately half that predicted by Diamessis and Redekopp [J. Phys. Oceanogr. 36, 784 (2006)], indicating that internal wave-induced benthic mixing may be even more prominent than previously thought.
Probing isomer interconversion in anionic water clusters using an Ar-mediated pump-probe approach: Combining vibrational predissociation and velocity-map photoelectron imaging spectroscopies
Authors: McCunn Laura R. , Gardenier George H. , Guasco Timothy L. , Elliott Ben M. , Bopp Joseph C. , Relph Rachael A. , Johnson Mark A.
Published: June 2008

We present the first results from an experiment designed to explore barriers for interconversion between isomers of cluster anions using an Ar-cluster mediated pump-probe technique. In this approach, anions are generated with many Ar atoms attached, and one of the isomers present is selectively excited by tuning an infrared laser to one of the isomer’s characteristic vibrational resonances. The excited cluster is then cooled by evaporation of Ar atoms, and the isomer distribution in the lighter daughter ions is measured after secondary mass selection by recording their photoelectron spectra using velocity-map imaging. We apply the method to the water hexamer anion, (H2O)6−, which is known to occur in two isomeric forms with different electron-binding energies. We find that conversion of the high-binding (type I) form to the low-binding (type II) isomer is not efficiently driven in (H2O)6− with excitation energies in the 0.4eV range even though it is possible to create both isomers in abundance in the ion source. This observation is discussed in the context of the competition between isomerization and electron autodetachment, which depends on the relative positions of the neutral and ionic potential surfaces along the isomerization pathway. Application of the method to the more complex heptamer ion, however, does reveal that interconversion is available among the highest binding isomer classes (I and I′).
Errors in ram velocity and temperature measurements inferred from satellite-borne retarding potential analyzers
Authors: Klenzing J. H. , Earle G. D. , Heelis R. A.
Published: June 2008

Retarding potential analyzers (RPAs) [Heelis and Hanson, Measurement Techniques in Space Plasmas, in Geophys. Monogr. Ser., Vol. 102 (AGU, Washington, D.C., 1998), p. 61] have been used extensively in space science over the past five decades to provide in situ estimates of ion velocities and temperatures. It has been shown previously that the use of biased grids in such instruments creates a nonuniform potential in the grid plane, which leads to errors in inferred parameters. A simulation of ion interactions with biased grids has been developed using a commercial finite-element analysis software package. Using a statistical approach, perturbations to the idealized RPA equation are discussed with the intent of developing quantitative corrections for the inferred parameters. The transparency of the grid stacks is found to be a function of particle energy and angle of attack. A preliminary case study is presented and compared to previous work.
Rotation effects of elongated dust particles on dust ion-acoustic surface waves in a Lorentzian plasma
Authors: Lee Myoung-Jae
Published: June 2008

The dispersion relation for a dust ion-acoustic surface wave is obtained for the semi-bounded dusty plasma containing elongated and rotating charged dust particles. The equilibrium plasma velocity distribution function is taken to be Lorentzian. Dust particles are assumed to be cold. The result shows that the frequency of the dust ion-acoustic surface wave propagating at the plasma-vacuum interface can be lowered by the increase of the angular rotation frequency of the elongated dust particles in the range that kxλe≳1, where kx and λe are the wave number and electron Debye length, respectively. In addition, the increase of the spectral index κ in the Lorentzian distribution function is found to increase the phase velocity of the wave, especially in the case that kxλe≲10. The influence of κ and wave number on the group velocity of the surface wave is also analyzed.