bluuebunny/crossref_metadata_2025 huggingface dataset:
Galápagos History, Restoration, and a Shifted Baseline
Authors: Bush Mark B. , Restrepo Alejandra , Collins Aaron F.
Published: May 2014

An ecological system that had been resilient to climatic change for thousands of years was transformed in decades by the introduction of livestock to the Galápagos. Habitat restoration at El Junco, San Cristobal Island, has included the exclusion of cattle, removal of exotic species, and replanting with the endemic shrub, Miconia robinsoniana. M. robinsoniana was known to form a characteristic zone of near mono‐dominant shrub cover at equivalent elevations on other islands. Analysis of modern and fossil pollen data from El Junco Crater Lake showed that two of the most common shrubs of the San Cristóbal uplands, Acalypha and Alternanthera, were the most common pollen types for more than two thousand years. In the 1930s, 30 years before the first scientific description of that habitat, the abundance of both taxa declined rapidly as livestock densities increased. The restoration target, based on the assumption that mono‐dominance by M. robinsoniana is the natural state, reflects a shifted baseline. Acalypha and Alternanthera should be considered for inclusion within future restoration efforts.
Flexible and Adaptable Restoration: An Example from South Korea
Authors: Temperton Vicky M. , Higgs Eric , Choi Young D. , Allen Edith , Lamb David , Lee Chang‐Seok , Harris James , Hobbs Richard J. , Zedler Joy B.
Published: May 2014

Ecological restoration is set to play a key role in mitigating biodiversity loss. While many restorationists worry about what to do about and what to call rapidly changing ecosystems (no‐analog, novel, or other terms), ecologists and managers in some parts of the world have avoided these controversies and proceeded with developing and implementing innovative restoration projects. We discuss examples from South Korea, including the Cheonggyecheon river project in Seoul and the new National Institute of Ecology, which combines scientific research, planted reference systems for future restoration, and an Ecorium for outreach and education. South Korea faces a range of restoration challenges, including managing even‐aged planted forests, major land use changes (especially urbanization) affecting valuable tidal flats, and fragmented landscapes caused by intensive land use and the fenced Demilitarized Zone (DMZ). The examples from South Korea provide insights that might guide future actions more broadly. These include flexible targets for restoration not based on historical precedents, considering ecosystem functions and functional trait diversity as well as species composition, creating model restoration projects, and managing adaptively.
The Unintended Consequences of Education Policies on South African Participation and Unemployment
Authors: Burger Rulof , van der Berg Servaas , von Fintel Dieter
Published: May 2014

In the late 1990s, theSouthAfricanDepartment ofEducation implemented two policies that were meant to reduce the large number of over‐aged learners in the school system: schools were no longer allowed to accept students who were more than two years older than the correct grade age, and students could not be held back more than once in each of four schooling phases. Our analysis uses school administrative data and household survey data to show that these policies coincided with a decrease in school enrolment of at least 400,000 and possibly more than 900,000 learners. These policies appear to have pushed many students into the labour market at earlier ages than was observed for previous generations, which explains much of the sudden increase in labour force participation and unemployment during this period. However, since these individuals would probably have entered the labour market sooner if not for their poor employment prospects, we argue that the resulting increase in unemployment signifies a more accurate reflection of disguised unemployment that already existed in the mid‐1990s rather than a deterioration of labour market conditions.
Carbon Monoxide–Releasing Molecule‐A1 Inhibits Th1/Th17 and Stimulates Th2 Differentiation In vitro
Authors: Nikolic I. , Vujicic M. , Stojanovic I. , Stosic‐Grujicic S. , Saksida T.
Published: May 2014

Carbon monoxide (CO) is endogenously produced by haeme oxygenase‐1 and has profound effects on intracellular signalling processes, generating anti‐inflammatory, antiproliferative and antiapoptotic effects. A boron‐containing compound CORM‐A1 is capable of releasing CO in such a way to mimic physiological functions of haeme oxygenase‐1. Considering the importance of Th1/Th17 versus Th2 balance in the final outcome of immune and inflammatory responses in this study we focused on immune‐modulatory effects of CORM‐A1 on murine lymph node–derived T cells in vitro and its influence on T‐cell proliferation, activation and differentiation. Anti‐CD3/CD28 antibody‐triggered lymph node cells proliferation remained unaffected after 24‐hour CORM‐A1 treatment, as well as the expression of the early activation marker CD25. However, CORM‐A1 successfully reduced the secretion of the two representative pro‐inflammatory cytokines, IFN‐γ and IL‐17, while the secretion of anti‐inflammatory cytokine IL‐4 remained unchanged. Furthermore, CORM‐A1 efficiently reduced the percentage of CD4+IFN‐γ+ and CD4+IL‐17+ cells, whereas CD4+IL‐4+ cell population increased after treatment. Also, CORM‐A1 significantly reduced expression of transcription factor RORγT, necessary for Th17 development, but the expression of Th1‐related and Th2‐related transcription factors (T‐bet and GATA‐3, respectively) remained unchanged. In conclusion, our findings indicate that CO has anti‐inflammatory role through the regulation of balance between pro‐inflammatory Th1/Th17 and anti‐inflammatory Th2 cells. Observed immunomodulatory effects of CORM‐A1 could be useful for developing novel therapeutic approaches in managing Th1/Th17‐mediated immune disorders.
Vitamin A Supplementation Reduces IL‐17 and RORc Gene Expression in Atherosclerotic Patients
Authors: Mottaghi A. , Ebrahimof S. , Angoorani P. , Saboor‐Yaraghi A.‐A.
Published: May 2014

Vitamin A is a potential mediator of T helper cells in atherosclerosis. The purpose of this study was to evaluate the effect of vitamin A supplementation on expression of Th17 cells‐related IL‐17 and RORc genes in atherosclerotic patients. Thirty one atherosclerotic patients and 15 healthy controls were studied for 4 months. Atherosclerotic patients were randomly divided into vitamin A or placebo groups. Healthy controls and patients in vitamin A group received 25,000 IU retinyl palmitate per day. Peripheral blood mononuclear cells were isolated, cultured and divided into three groups including fresh cells, phytohemagglutinin (PHA)‐activated T cells and ox‐LDL‐activated T cells. Gene expressions of T cells were studied by real‐time PCR. In atherosclerotic patients, vitamin A supplementation resulted in significant decrease in IL‐17 gene expression by 0.63‐fold in fresh cell, 0.82‐fold in PHA‐activated cells and 0.65‐fold in ox‐LDL‐activated cells (P < 0.05 for all). RORc gene expression in fresh cells as well as ox‐LDL‐activated cells decreased significantly after vitamin A supplementation in atherosclerotic patients (P = 0.0001 for both). In PHA‐activated cells, vitamin A supplementation significantly decreased RORc gene in both atherosclerotic patients and healthy subjects by 0.87‐fold and 0.72, respectively, while in placebo group, the RORc gene expression significantly increased by 1.17‐fold (P < 0.05 for all). Findings of this study suggest that vitamin A supplementation may be an effective approach to slow progression of atherosclerosis.
Establishment of culture systems for Genotypes 3 and 4 hepatitis E virus (HEV) obtained from human blood and application of HEV inactivation using a pathogen reduction technology system
Authors: Owada Takashi , Kaneko Moe , Matsumoto Chieko , Sobata Rieko , Igarashi Masashi , Suzuki Ko , Matsubayashi Keiji , Mio Kazuhiro , Uchida Shigeharu , Satake Masahiro , Tadokoro Kenji
Published: May 2014

Background

It has been demonstrated that the hepatitis E virus (HEV) can be transmitted via blood transfusion, and the risk of HEV transmission via transfusion has become a major global concern. An HEV culture system for blood‐derived HEV has been sought to obtain valuable knowledge of the virus and the risk of HEV infection through blood products.

Study Design and Methods

We endeavored to establish an HEV culture system using RNA‐positive blood specimens for Genotypes (G) 3 and 4 and applied this system to evaluate tissue culture infectious dose (TCID). We applied this method to investigate the potential of the Mirasol pathogen reduction technology (PRT) system (Terumo BCT) to inactivate live HEV in contaminated platelet samples (PLTs). PLTs were spiked with cultured HEV G3 or G4 and then treated with the Mirasol PRT system. PLTs were examined before and after the treatment for HEV load using TCID titration.

Results

We successfully established two strains for HEV production: the JRC‐HE3 strain for G3 and the UA1 strain for G4. The Mirasol PRT system expressed more than 3 log inactivation for JRC‐HE3 and more than 2 log inactivation for UA1.

Conclusion

The Mirasol PRT system inactivated greater than 2 to 3 logs of live HEV in PLTs and can potentially be used to lower the possibility of blood‐borne HEV transmission. The G3 and G4 HEV inocula identified in this study and the hepatoma cell culture system provide a new means to assess HEV infectious titer and to evaluate other pathogen reduction strategies.
Fourteen‐year experience of a tertiary hospital transfusion committee in West Africa
Authors: Opare‐Sem Ohene , Bedu‐Addo George , Karikari Patrick , Boateng Peter , Sarkodie Francis , Rahman Rabiniatu , Asenso‐Mensah Kwame , Awuah Baffour , Osei Akoto Alex , Munin S.A. Abdul , Mensah‐Acheampong Fred , Allain Jean‐Pierre , Owusu‐Ofori Shirley
Published: May 2014

Background

Hospital transfusion committees (HTCs) have been established in the United States to link producers and users as well as to ensure appropriate use of blood. The HTC has been little reported in sub‐Saharan Africa (SSA), although it has been established in some hospitals.

Study Design and Methods

The minutes of three to four HTC meetings per year in a tertiary hospital hosting its own blood service have been reviewed to examine the HTC role over a period of 14 years. Minutes were broken down into themes and indexes, and incomplete data were reinforced by other information sources. Specific data on progress over time were reviewed.

Results

The HTC systematically scrutinized the blood supply, blood safety, donor care, clinical use of blood products, and costs. It operated more as a blood transfusion service supervisory board than the limited function allocated to western HTCs. Clinicians and hospital administration were directly involved in decision making and directing investigations to support potential changes and advances in the role and function of the blood transfusion service. The close relation with a UK major blood center and university laboratory provided the impetus and support for research and investigations preliminary to decision making. Data collected and analyzed were reported in the international literature and contributed to disseminate progress made.

Conclusions

The HTC in a major SSA tertiary hospital inclusive of all sections of hospital organization was critically instrumental in decision making, funding, and implementing measures improving the amount and quality of blood products on the basis of evidence collected despite lack of resources. Steps are taken to ensure sustainability of the HTC.
Inactivation of dengue virus in plasma with amotosalen and ultraviolet A illumination
Authors: Musso Didier , Richard Vaea , Broult Julien , Cao‐Lormeau Van‐Mai
Published: May 2014

Background

Dengue virus (DENV) is the most prevalent arbovirus in tropical and subtropical regions. Transfusion‐transmitted DENV infections have already been reported and the risk for blood products to be contaminated by DENV needs to be considered in dengue‐endemic areas, especially during outbreaks. Blood product inactivation processes, including amotosalen and ultraviolet A (UVA) illumination, have been developed to reduce transfusion‐transmitted infections. In this study we demonstrate the efficiency of using amotosalen and UVA illumination for DENV inactivation in human plasma.

Study Design and Methods

Plasma units from volunteer blood donors were spiked with DENV. Viral titers and viral RNA loads were measured in plasma before and after amotosalen and UVA photochemical treatment.

Results

The mean DENV titer in plasma before inactivation was 5.61 log 50% tissue culture infectious dose (TCID50)/mL and the mean viral RNA load was 10.21 log copies/mL. In inactivated plasma, the mean DENV RNA load was 9.37 log copies/mL, but cell cultures inoculated with inactivated plasma did not result in infected cells and did not produce any replicative virus nor detectable viral RNA.

Conclusion

We report here that amotosalen combined with UVA light inactivated DENV in fresh‐frozen plasma (5.61 log inactivation of viral titer). This inactivation process is an efficient method to prevent plasma transfusion‐transmitted DENV infections.
Cerebral Doppler velocimetry to predict fetal anemia after more than three intravenous fetal exchange transfusions
Authors: Hermann Monika , Poissonnier Marie‐Hélène , Grangé Gilles
Published: May 2014

Background

We aimed to assess usefulness of the middle cerebral artery peak systolic velocity (MCA‐PSV) in the prediction of fetal anemia after more than three intravenous fetal‐exchange transfusions (IFET).

Study Design and Methods

A retrospective study was conducted over 6 years of 15 consecutive pregnancies with severe red blood cell fetomaternal alloimmunization requiring more than three IFETs. We evaluated correlation between MCA‐PSV (expressed as multiples of the mean [MoM]) and pretransfusion hemoglobin (Hb) in the fetus (MoM). Analyses were also performed to assess the value of MCA‐PSV to predict moderate to severe fetal anemia.

Results

Twenty‐seven MCA‐PSV measurements performed before the fourth to last IFET were coupled with pretransfusion Hb in the fetus. The median number of IFETs per fetus was five (range, four to eight). Five Hb samples found fetuses with severe (19%), seven with moderate (26%), and 15 with mild anemia (56%). There was a linear correlation between MCA‐PSV(x) and Hb in the fetus(y): y = −0.21x + 0.93 (r = −0.50, p < 0.01). For the prediction of moderate to severe anemia the negative predictive value of MCA‐PSV with a threshold of 1.5 MoM was 75%, positive predictive value 73%, specificity 80%, sensibility 67%, and positive likelihood ratio 3.33. The area under the receiver operating characteristic curve was 0.78 (95% confidence interval, 0.59‐0.96; p < 0.001). For the prediction of severe anemia, MCA‐PSV with a threshold of 1.5 MoM had 94% negative predictive value, 80% sensibility, and a positive likelihood ratio of 2.5.

Conclusions

This study shows that a correlation between MCA‐PSV and Hb in the fetus persists even after more than three IFETs. MCA‐PSV measurements thus remain useful to monitor fetuses at risk of anemia.
CONTRAST‐ENHANCED ULTRASONOGRAPHIC FINDINGS IN THREE DOGS WITH PANCREATIC INSULINOMA
Authors: Nakamura Kensuke , Lim Sue‐Yee , Ochiai Kenji , Yamasaki Masahiro , Ohta Hiroshi , Morishita Keitaro , Takagi Satoshi , Takiguchi Mitsuyoshi
Published: May 2014

Abdominal ultrasonography is one of the most common diagnostic imaging modalities used for dogs with suspected insulinoma; however, pancreatic masses are clearly identified in fewer than half of affected dogs and benign pancreatic nodules can be difficult to differentiate from malignant ones. The purpose of this prospective study was to describe contrast‐enhanced ultrasonography (CEUS) characteristics of confirmed pancreatic insulinoma in a group of dogs. Inclusion criteria were as follows: (1) repeated hypoglycemia (blood glucose levels <60 mg/dl, twice or more); (2) elevated blood insulin levels with hypoglycemia; (3) pancreatic nodules detected with conventional ultrasonography; and (4) histological confirmation of pancreatic islet cell carcinoma. Immediately following conventional ultrasonography of the entire abdomen, CEUS of the pancreatic nodule and adjacent parenchyma was performed using contrast‐specific technology pulse inversion imaging and perflubutane microbubble contrast agent. Three dogs met inclusion criteria. Pancreatic nodules in all the three dogs became more clearly demarcated after injection of the contrast agent. Each nodule showed different enhancement patterns: markedly hyperechoic for 5 s, slightly hyperechoic for 1 s, and clearly hypoechoic for over 30 s. These results were not in complete agreement with previously reported CEUS findings in human patients with insulinoma. All nodules were surgically resected and histopathologically confirmed as malignant insulinomas. Findings from the current study indicated that contrast‐enhanced ultrasound may help to increase conspicuity of pancreatic insulinomas in dogs and that enhancement characteristics may be more variable in dogs than in humans.
Algorithm to Construct Line-Shaped Feature Point Clouds of Single-Value Ruled Blades for Gas Turbines
Authors: Zhou Yu , Wang Hao-chen , Du Fa-rong , Ding Shui-ting
Published: May 2014

Using the geometric features of surfaces, we proposed an algorithm to construct line-shaped feature point clouds for the reverse design of a blade surface. Blade surfaces in the gas turbines field require high accuracy and have complex shapes. By quickly recognizing the border of the scattered point clouds of blades, the back-project method was used to extract the ruled generatrix vector. By solving the multi-objective optimization problem of border point clouds, the annealing algorithm was applied to match border point clouds nonrigidly. Equally divided points were constructed based on the point clouds registration results to get inerratic-orderly line-shaped feature point clouds that are beneficial for generating high quality blade surfaces quickly. The proposed algorithm is very effective for dealing with the point clouds of single-value ruled blades. It is also theoretically significant and may be applied for reconstructing the surface of point clouds of single-value ruled blade surfaces. Experiments verify the feasibility of the proposed algorithm.
Soundscape and architecture—What is your vision?
Authors: Brooks Bennett M. , Paoletti Dennis
Published: May 2014

The soundscape technique combines physical acoustical parameters with user perceptions of the sonic environment in a context of meaning. This method can be a powerful analysis and design tool for a wide range of projects, including building interior and exterior spaces, site planning, urban and transportation planning, environmental noise control, public parks, etc. The soundscape method can also be a useful marketing and project management tool, with the goal to address acoustical concerns as early as possible in the architectural design process, even in the inspiration phase. Sonic perceptions of the built environment are often a vital part of the vision for a project, and must be expressed at the outset to be fully incorporated in the design. Innovative project delivery methods and contract structures such as Integrated Project Delivery (IPD), unlike design-bid-build, assign shared risk and reward among the design, construction, and management teams. Design inputs are solicited from all stakeholders and design team members very early, before programming. This and similar delivery methods offer great opportunities for practitioners, through soundscaping, to include acoustics in the initial project discussions, and to advance the implementation of quality sonic environments. Project case study examples are discussed.
The challenge of interdisciplinarity in soundscape
Authors: Schulte-Fortkamp Brigitte
Published: May 2014

Interdisciplinarity is one of the most stressed player in Soundscape. Over time when starting to collaborate in and with different disciplines, it became obvious that it is necessary to understand the needs in soundscapes as well as the use of soundscape techniques in the respective disciplines. One of the most important outcomes in the COST project on Soundscape TD 0804 with respect to... that a common language is needed to guarantee the collaboration. Especially in the field of Architecture, there is the need to understand why Soundscape and landscape have some similarities but also that landscape and soundscape are different in their focus. The paper will discuss understandings and misunderstandings in the respective fields and provide an orientation guideline.
Spatial stream segregation by cats, rats, and humans
Authors: Middlebrooks John C. , Bremen Peter , Javier Lauren K. , Yao Justin D.
Published: May 2014

Spatial hearing aids a listener in disentangling multiple competing sound sequences. We find that separation of around 10° between target and masker sound sources permits humans and cats to hear interleaved sound sequences as segregated streams, thus enabling a “rhythmic masking release” task requiring recognition of target rhythms. In cats and rats, neurons in primary auditory cortex (A1) exhibit spatial stream segregation in that they synchronize selectively to one of two interleaved sequences of noise burst originating from spatially separated sources. Cortical spatial selectivity is markedly sharper under competing-sound conditions compared to that observed with single sound sources. Cortical responses are predicted well by a model that incorporates moderate spatial selectivity inherited from the brainstem sharpened by forward suppression at the level of thalamocortical synapses. Consistent with that model, spatial stream segregation in rats is stronger in cortical area A1 than in the ventral division of the medial geniculate body, its principal source of thalamic input. In cats, psychophysical performance was better for high-frequency sounds, and cortical stream segregation was stronger for neurons having high characteristic frequencies. In contrast, human psychophysics was better for low-frequency sounds, suggesting that the larger heads of humans provide them with greater interaural time differences.
Temporal and spatial coherence as cues for across-frequency grouping in treefrogs
Authors: Bee Mark
Published: May 2014

Humans exploit environmental regularities in sounds to perceptually bind acoustic energy occurring simultaneously at different frequencies. Such abilities influence vowel perception in speech and timbre perception in music. Other animals solve similar binding problems in the recognition of species-specific acoustic signals. Moreover, they commonly do so using auditory systems that differ in notable ways from that of mammals. This study of two treefrog species investigated temporal and spatial coherence as cues that promote grouping of two spectral bands emphasized in their acoustic signals. In two-alternative choice tests, females preferred temporally and spatially coherent calls over alternatives in which the onsets/offsets of the two bands were time-shifted by more than 25 ms or in which the two bands were spatially separated by 7.5° or more. These results, which suggest temporal coherence and spatial coherence promote across-frequency auditory grouping, are notable given differences in how the two spectral bands are processed by the anuran auditory system. Sound energy in the high- and low-frequency bands primarily enters the auditory system via different pathways (tympanum and body wall, respectively) and is encoded primarily by different papillae in the inner ear (basilar papilla and amphibian papilla, respectively).
Release from auditory masking with complex signals and complex noise in the bottlenose dolphin (Tursiops truncatus)
Authors: Branstetter Brian K. , Trickey Jennifer S. , Bakhtiari Kimberly L. , Black Amy , Finneran James J.
Published: May 2014

Dolphins are social animals that rely heavily on passive and active acoustics for communication, navigation, foraging, and detecting predators. Auditory masking, from both natural and anthropogenic noise sources, may adversely affect these fitness-related capabilities. The dolphin's ability to detect a variety of complex signals (both dolphin phonations and tonal signals) masked by Gaussian, comodulated, snapping shrimp, and ice squeaks noise was tested. Detection thresholds were measured using a go/no-go adaptive staircase procedure. Masking patterns were similar for all signals (whistles, burst-pulse, and pure tones) except for click signals. Masking from ice squeaks resulted in the largest masked thresholds, while snapping shrimp and comodulated noise resulted in a release from masking relative to thresholds from Gaussian noise. Click signals were most difficult to detect when masked by snapping shrimp. Recognition thresholds were estimated for whistle-like signals using a cross-modal, matching-to-sample procedure. Recognition thresholds were on average 4 dB greater than detection thresholds for all noise types. The auditory mechanisms governing the results are discussed. [Work supported by the ONR.]
Getting more for less: Increasing the accessibility of water column sonar data for fisheries management
Authors: Wall Carrie C. , Anderson Charles , McLean Susan J.
Published: May 2014

Active acoustic technology is of increasing importance for studies examining fish populations and biological abundance in the water column. Multibeam echosounders are employed routinely on NOAA fishery vessels to estimate biomass, conduct trophic- and species-level identification, measure school morphology and behavior, and characterize habitat for commercially important species. These surveys deliver valuable information for ecosystem-based fisheries management but they also produce massive amounts of data that are costly and difficult to maintain. With its ability to store and preserve large datasets, NOAA's National Geophysical Data Center is acquiring and archiving acoustic data collected from NOAA and academic fleets. Through these efforts, an accessible archive of acoustic water column data will be made available to researchers and the public around the world. A web-based search engine will allow anyone to identify where data were collected, what instrument was used, and access the raw data and associated products. Years of decreasing funding for the sciences have necessitated our ability to get more information and more users out of data currently collected. This globally accessible archive is a large step in that direction. Of most importance is identifying how best to tap the archive to benefit current and future fisheries research and management.
Detection of fish near the bottom with a hull-mounted multibeam echosounder
Authors: de Moustier Christian
Published: May 2014

In single-beam or split-beam fisheries echosounding, bottom echoes often mask echoes from fish hovering near the bottom. Likewise, in down-looking multibeam echosounding bottom echoes received in the main lobe of near normal incidence beams appear in the sidelobes of the other beams and obscure weaker echoes received at the same range in the mainlobe of these other beams. Some multibeam sonars use frequency division multiplexing to avoid crosstalk between beams. However, it was shown recently [de Moustier, Proc. MTS/IEEE OCEANS'13, San Diego, September 23–27, 2013] that detection of fish near the seafloor is possible with a multibeam echo-sounder operating at a single acoustic frequency. This is achieved with a signal processing technique based on the ordered statistic constant false alarm rate (OS-CFAR) detection method used in radar. Here, the OS-CFAR operator is applied in the angle domain, rather than the customary range domain, and it estimates the signal-to-clutter ratio across all angles at a given time slice or range increment at the output of the beamformer. In this context, clutter encompasses both clutter and noise against which the desired signal is to be detected. Data collected with a 160 kHz multibeam echosounder are used to demonstrate the technique.
Scattering and reverberation from fish schools in the 500–1500 Hz band
Authors: Newhall Arthur , Lin Ying-Tsong , Lynch James F. , Gawarkiewicz Glen G. , Grothues Thomas M.
Published: May 2014

We will report on the results from an experiment off Cape Hatteras, North Carolina, to look at scattering and reverberation from fish schools in the 500–1500 Hz band. The experiment, which was performed during the period May 12–29, 2012, was a joint acoustics, biology, and physical oceanography effort, with distinct, but coordinated, goals in each area. Acoustically, we wished to examine the scattering of sound from fish schools over a full range of azimuthal angles. To do this, we employed a source mounted on an autonomous vehicle and a moored, four element array receiver. The source traveled around the fish school and the receiver, giving the desired angular diversity. Video images, sidescan sonar, and direct sampling of the school allowed us to quantify the in-situ scattering field. Estimates for attenuation and scattering versus azimuthal angle will be presented. Directions for analysis and further research will be discussed.
Deep sea organisms density estimation using a Dual Frequency Identification Sonar (DIDSON)
Authors: Giorli Giacomo , Copeland Adrienne M. , Au Whitlow W. , Polovina Jeff
Published: May 2014

Estimating the density of organism living in deep sea scatting layers is of key importance for understanding the biomass in the mesopelagic layers. Scientific echosounders are routinely used for this task; however, new imaging sonar technologies pose the opportunity for estimating density of organism, as well as identification at smaller scales. During the 2013 NOAA KONA Integrated Ecosystem, a Dual Frequency Identification Sonar (DIDSON) (SoundMetrics Inc.) was used to estimate the density, length of organisms in the deep sea scattering layers during nighttime and daytime along the KONA coast of the island of Hawaii. At each station, an EK60 38 kHz echosounder was used to find the depth of the deep sea scattering layers, and the DIDSON was lower into the layer (or layers if two were present) (about 500 and 600 m), and underneath the deeper layer (about 800 m). A total of 4621 organisms were counted and sized. We estimated densities ranging from 6 to 1 organism/m3. Density shows some variation between locations and depth and organism as big as 3 m were sighted.
Clinical breast imaging with ultrasound tomography: A description of the SoftVue system
Authors: Duric Neb , Littrup Peter , Roy Olivier , Li Cuiping , Schmidt Steve , Cheng Xiaoyang , Janer Roman
Published: May 2014

We describe the technical design and performance of SoftVue, a breast imaging device based on the principles of ultrasound tomography. SoftVue's imaging sensor is a ring shaped transducer operating at 3 MHz and consisting of 2048 elements. Data acquisition is achieved through 512 receive channels. The transducer encircles the breast, which is immersed in warm water while the patient lies in a prone position. The transducer is translated vertically to acquire data from the entire breast. The acquired data are used to reconstruct images using tomographic inversions. The reconstruction engine is based around a blade-server design that houses multiple CPUs and GPUs. Separate algorithms are used to reconstruct reflection, sound speed, and attenuation images. A patient scan generates a stack of each type of image. The system was designed with the clinical goal of detecting and characterizing breast masses based on their biomechanical and morphological properties. Ongoing clinical studies are being used to assess the performance of the system under realistic clinical settings. Results of the clinical assessment are presented. [The authors acknowledge research support from the National Cancer Institute (5 R44 CA165320-03). Neb Duric and Peter Littrup also acknowledge that they have financial interests in the SoftVue technology.]
Improving ultrasound-based estimates of vector displacement fields in elastography applications
Authors: Yengul Sanjay S. , Babaniyi Olalekan A. , Meral Faik C. , Madore Bruno , Barbone Paul E.
Published: May 2014

Ultrasound elastography is based on estimating tissue displacement using ultrasound imaging technology. The displacement field of interest may be the result of either an external quasistatic deformation (i.e., strain imaging), or a propagating shear wave (i.e., radiation force imaging), or some other excitation. Ultrasound image data with standard beamforming can provide very precise measurements of soft tissue displacement in the axial direction, i.e., in the direction of the ultrasound beam. Lateral (and elevational) displacement estimates are relatively noisy. This observation demonstrates that the quality of displacement estimates depends on the ultrasound image formation method. In this contribution, we evaluate the precision of axial and lateral displacement estimates obtained using different image formation methods. Ultrasound data from a Verasonics V-1 system (Redmond, WA) is used, which provides access to the raw signal from each element of the transducer array, thereby allowing beamforming to be done in software as a post-processing step. Using information from a mechanics-based model [Babaniyi et al., J. Acoust. Soc. Am. 134, 4011 (2013)] further improves the precision of the displacement field estimate. We will present the results and discuss the next steps.
Animations illustrating the reflection of longitudinal sound wave pulses
Authors: Russell Daniel A.
Published: May 2014

The reflection of transverse wave pulses from a fixed or free boundary may be demonstrated physically in the classroom using an elastic string under tension. Animations of transverse wave pulses reflecting from hard and soft boundaries clearly indicate the phase relationship between incident and reflected signals. However, demonstrating similar phenomena for longitudinal waves difficult. The reversal of longitudinal waves in a spring may be physically demonstrated, but not the phase relationship between incident and reflected wave pulses. A microphone and digital oscilloscope may be used to demonstrate the phase change in pressure for reflections from the open end of a pipe, and the lack of phase change for reflections from a rigid end, but such demonstrations do not illustrate the longitudinal behavior of the wave motion at the boundary during reflection. This paper will showcase animations of longitudinal wave pulses reflecting from fixed and free boundaries, with an emphasis the appropriate phase changes upon reflection, with clarification of relationships between particle displacement, particle velocity, and pressure for longitudinal waves traveling in positive and negative directions. Discussion will include ways these animations may be used to improve student understanding.
Architectural acoustics illustrated, animated, designed, and built
Authors: Ermann Michael , Nanji Nawazish , Argentina Vinny , Yourshaw Matt , Zawistowski Marie , Zawistowski Keith , Duda Lauren , Ezure Megumi , Stephenson Samantha , Terrill Taylor , Shelton Ian , Yeh Samantha , Lee Kyle , Duong Huy , Sikora Brent , Naegele Leo , Atkins Tyler , Ellison Derek , Nelson Margaret , Schafer Leah , Skelton Emarie
Published: May 2014

In this line of pedagogy, architectural acoustics is filtered through the graphic and built language of architecture. First, a series of animations were created to explain room acoustics to architecture students. The impulse response as a concept is inherently spatial and dynamic. It can be explained with text, and it can be explained more clearly when illustration is included, but because the path of sound and the loudness at a receiver fluctuates with time, it can be best explained with a narrated animation (available online). Second, the physics of sound, room acoustics, and noise control were illustrated as part of a book, Architectural Acoustics Illustrated (Wiley, 2015). Building material choices, spatial relationships, best-practices, and data were explored through drawing; non-obvious and counter-intuitive graphic findings are presented. Finally, 15 architecture students explored room acoustics through ray tracing and auralization software. Then they designed and built an amphitheater for the town of Clifton Forge, Virginia. The completed project was widely published, was the subject of a documentary film, and earned award recognition from the American Institute of Architects.
Demonstrations and laboratory experiments in a senior level acoustics course
Authors: Korman Murray S.
Published: May 2014

The Physics Department at the U.S. Naval Academy has a senior level four credit course (SP436) in acoustics (called “Acoustics”) that features a well-equipped laboratory including an anechoic chamber. The course is populated by Physics Majors along with a few Engineering Majors at times. This presentation will show how Mathematica 9 is used in the laboratory portion of the course to enhance lecture topics and student computational assignments. It is “hands-on” which helps motivate and enhance learning. Students learn the fundamentals of Mathematica as part of the laboratory experience. Tasks after data collection, including analysis and write-up, are done with this software. Workstations include laptop personal computers, spectrum analyzers, oscilloscopes, laser Doppler vibrometers, and various accelerometers, mics, hydrophones, and ultrasonic transducers. A demonstration of standing waves in a cylindrical cavity will be presented as a representation of some of our featured lab experiments—including: Helmholtz resonators, linear and nonlinear vibration of a circular membrane, or circular elastic plate, flexural waves on a thin bar, Chladni plates, the hanging oscillating chain, spectral analysis (Fourier series, Fourier integral), sound speed vs. temperature and salinity, acoustic landmine detection, moving coil loud speaker, waves on strings, transmitting arrays, and wave guide studies.
YouTube EDU: Inspiring interest in acoustics through online video
Authors: Wilson Michael B.
Published: May 2014

The Internet is changing the face of education in the world today. More people have access to more information than ever before. The Khan Academy, iTunes U, YouTube EDU, and other programs are providing educational content for free to millions of Internet users worldwide. This content ranges from interesting facts that introduce a topic to entire undergraduate courses. And just as acoustics is an underrepresented science at the secondary and undergraduate levels, acoustics is an underrepresented science in the world of online education. But that is changing. Online content is being created focusing on clarifying misconceptions and sparking an interest in the field of acoustics. These videos are available without charge to everyone in the world.
Aging and lexical neighborhood effects in competing speech perception
Authors: Helfer Karen S. , Costanzi Angela , Laakso Sarah
Published: May 2014

Little is known about the extent to which lexical neighborhood effects are influenced by the presence of to-be-ignored messages. When the competing signal is understandable speech, words in the masker may activate their own lexical neighbors, causing increased competition for word identification. Older adults may have particular difficulty inhibiting lexical activation. This poster will present results of an examination of lexical neighborhood influences on competing speech perception. Sentences were developed in which we manipulated the neighborhood density and frequency of key words to create lexically easy (low density or high frequency of usage) and lexically difficult (high density or low frequency) stimuli lists. Pairs of sentences were created in which one sentence was lexically easy (in terms of density or frequency) and one was difficult. The target sentence was always spoken by the same talker and could be either lexically easy or difficult. Participants were younger (18–23 years), middle-aged (45–59 years), and older (>60 years) adults; they also completed a battery of cognitive tests. This poster will show results of analyses comparing lexical neighborhood effects among the participant groups, as well as how these effects are influenced by hearing loss and cognitive abilities. [Work supported by NIH DC012057.]
Masked speech recognition in school-age children and adults: Effects of age, masker type, and context
Authors: Leibold Lori , Buss Emily , Hall Joseph W.
Published: May 2014

This study evaluated the influences of age, masker type, and context on masked speech recognition. A repeated-measures design compared the speech recognition thresholds of two age groups of children (5–7 and 9–13 years) and a group of adults (19–33 years) in a continuous speech-shaped noise or a two-talker speech masker. Target stimuli were disyllabic words that were familiar to young children. Masker level was fixed at 60 dB SPL, and signal level was adapted to estimate the SNR required for 70.7% correct performance. Each listener completed testing in each masker condition using both an open-set task requiring a verbal response, and a 4AFC closed-set task requiring a picture-pointing response. Consistent with previous studies, and regardless of response context, larger and more prolonged child-adult differences were observed in the two-talker compared to the speech-shaped noise masker. Poorer performance was observed for all three age groups using the open-set compared to the closed-set context. This performance gap was similar across the three age groups in the speech-shaped noise masker, but a developmental effect was observed in the two-talker masker. Specifically, the decrement in performance using the open-set compared to the closed-set procedure increased with age in the two-talker masker.
Priming in speech perception through captions and sign language
Authors: Freyman Richard L. , Rost Gwyneth C. , Boothroyd Derina S. , Morse-Fortier Charlotte , Griffin Amanda M. , Poissant Sarah F.
Published: May 2014

When listeners know the content of the message they are about to hear, distorted or partially masked speech appears dramatically more intelligible compared to when the content is unknown. In the current research this priming phenomenon was investigated quantitatively using a same-different task where the prime and auditory message match on only 50% of trials. The first experiment was concerned with the effect of the timing of typed captions relative to the auditory message. For nonsense sentences subjected to four different types of distortion and masking, optimum performance was achieved when the initiation of the text preceded the acoustic speech signal by 800 ms. Performance was slightly poorer with simultaneous delivery and much poorer when the auditory signal preceded the caption. The second experiment investigated whether priming effects could be observed when the prime was delivered by sign language rather than captions. Preliminary results with normal-hearing signers indicate that some benefits in same-different performance can be triggered by sign language primes. Confirmation of this result and extension to listeners with hearing impairment who use sign and speech together in simultaneous communication (SimCom) may inform best practices for the use of SimCom in educational and other settings. [Work supported by NIDCD 01625 and The Hearing Health Foundation.]
Ear effect and gender difference of spontaneous otoacoustic emissions in children with auditory processing disorder
Authors: Zwissler Kimberly , Nagao Kyoko , Greenwood L. Ashleigh , Gaffney Rebecca G. , Cardinale R. Matthew , Morlet Thierry
Published: May 2014

Spontaneous otoacoustic emissions (SOAEs) are found in most healthy ears and can be used to measure the health of the cochlear structures and feedback mechanism. According to existing literature, right ears tend to exhibit greater numbers of SOAEs than left ears (Bilger et al., 1990) and females tend to show higher incidence of SOAEs than males (Moulin et al., 1993). The SOAE prevalence has not been extensively studied in children with auditory processing disorder (APD), a disorder with unknown etiology that reduces one's ability to process auditory information. This study examined the prevalence and ear advantage of SOAEs between genders in children diagnosed with APD. SOAEs were investigated in 19 children (7 girls and 12 boys) with APD and 24 typically developing children (14 girls and 10 boys) aged 7–12. Right ear advantage was more prevalent in control (71%) than APD subjects (42%). However, over 30% more females exhibited a right ear advantage than males in each group. Although the results are not significant, our findings indicate that the lack of right ear advantage for SOAE is more prevalent in children with APD, particularly in males, suggesting that cochlear mechanisms or their control might be somehow affected in APD.
Testing a nonlinear computational channel model for masker phase effects
Authors: Oh Yonghee , Hoglund Evelyn M. , Feth Lawrence L.
Published: May 2014

The masked threshold differences produced by Schroeder-phase maskers are most often attributed to the non-linear response of the normal cochlea (Summers et al., 2003). The nonlinear properties of the basilar membrane (BM) cause different response to the positive and negative Schroeder-phase maskers (i.e., + SCHR and -SCHR maskers, respectively) based on signal level, temporal synchrony, and on- and off-frequency harmonic components (Kohlrausch and Sander, 1995, Carlyon and Datta, 1997a,b, and Summers, 2000). In this study, manipulation of harmonic components of the maskers was used to explore nonlinear aspects of BM motion produced by the two different maskers. Specifically, masking period patterns (MPPs) for the + SCHR and -SCHR maskers were measured to show the influence of the phase relationships, and thus, the spectrotemporal characteristics of harmonic complexes on masking effectiveness. An enhanced channel model (Oh, 2013) provides a quantitative explanation for masking differences between + SCHR and -SCHR maskers by introducing nonlinear channel correlation across both frequency and time and a nonlinear decision criterion. [Research supported by a grant from the Office of Naval Research #N000140911017.]
Dual-carrier vocoder: Evidence of a primary role of temporal fine structure in streaming
Authors: Apoux Frederic , Youngdahl Carla L. , Yoho Sarah E. , Healy Eric W.
Published: May 2014

Thus far, two possible roles of temporal fine structure (TFS) have been suggested for speech recognition. A first role is to provide acoustic speech information. A second role is to assist in identifying which auditory channels are dominated by the target signal so that the output of these channels can be combined at a later stage to reconstruct the internal representation of that target. Our most recent work has been largely in contradiction with the speech-information hypothesis, as we generally observe that normal-hearing (NH) listeners do not rely on the TFS of the target speech signal to obtain speech information. However, direct evidence that NH listeners do rely on the TFS to extract the target speech signal from the background is still lacking. The present study was designed to provide such evidence. A dual-carrier vocoder was implemented to assess the role of TFS cues in streaming. To our knowledge, this is the only strategy allowing TFS cues to be provided without transmitting speech information. Results showed that NH listeners can achieve sentence recognition scores comparable to that obtain with the original TFS (i.e., unprocessed), suggesting a primary role of TFS cues in streaming. Implications for cochlear implants are discussed.