Application of Suction-cup-attached VHF Transmitters to the Study of Beluga, Delphinapterus leucas, Surfacing Behavior in Cook Inlet, Alaska

Suction-cup-attached VHF radio transmittes were deployed on belugas, Delphinapterus leucas, in Cook Inlet, Alaska, in 1994 and 1995 to characterize the whales' surfacing behavior. Data from video recordings were also used to characterize behavior of undisturbed whales and whales actively pursued for tagging. Statistics for dive intervals (time between the midpoints of contiguous surfacings) and surfacing intevals (time at the surface per surfacing) were estimated. Operations took place on the tidal delta of the Susitna and Little Susitna Rivers. During the 2-yr study, eight whales were successfully tagged, five tags remained attached for >60 min, and data from these were used in the analyses. Mean dive interval was 24.1 sec (interwhale SD=6.4 sec, n=5). The mean surfacing interval, as determined from the duration of signals received from the radio transmitters, was 1.8 sec (SD=0.3 sec, n=125) for one of the whales. Videotaped behaviors were categorized as "head-lifts" or "slow-rolls." Belugas were more likely to head-lift than to slow-roll during vessel approaches and tagging attempts when compared to undisturbed whales. In undisturbed groups, surfacing intervals determined from video records were significantly different between head-lifting (average = 1.02 sect, SD=0.38 sed, n=28) and slow-rolling whales (average = 2.45 sec, SD=0.37 sec, n=106). Undisturbed juveniles exhibited shorter slow-roll surfacing intervals (average = 2.25 sec, SD=0.32 sec, n=36) than adults (average = 2.55 sec, SD=0.36 sec, n=70). We did not observe strong reactions by the belugas to the suction-cup tags. This tagging method shows promise for obtaining surfacing data for durations of several days

Detecting Pulsars with Interstellar Scintillation in Variance Images

Pulsars are the only cosmic radio sources known to be sufficiently compact to show diffractive interstellar scintillations. Images of the variance of radio signals in both time and frequency can be used to detect pulsars in large-scale continuum surveys using the next generation of synthesis radio telescopes. This technique allows a search over the full field of view while avoiding the need for expensive pixel-by-pixel high time resolution searches. We investigate the sensitivity of detecting pulsars in variance images. We show that variance images are most sensitive to pulsars whose scintillation time-scales and bandwidths are close to the subintegration time and channel bandwidth. Therefore, in order to maximise the detection of pulsars for a given radio continuum survey, it is essential to retain a high time and frequency resolution, allowing us to make variance images sensitive to pulsars with different scintillation properties. We demonstrate the technique with Murchision Widefield Array data and show that variance images can indeed lead to the detection of pulsars by distinguishing them from other radio sources.Comment: 8 papes, 9 figures, accepted for publication in MNRA

Seismic oceanography imaging of thermal intrusions in strong frontal regions

The Naval Research Laboratory and collaborating partners carried out two dedicated seismic oceanography field experiments in two very different strong frontal regions. ADRIASEISMIC took seismic oceanography measurements at the confluence of North Adriatic Dense Water advected along the Western Adriatic Current and Modified Levantine Intermediate Water advected around the topographic rim of the Southern Adriatic basin. ARC12 took seismic oceanography measurements in and around the Agulhas Return Current as it curved northwards past the Agulhas Plateau and interacted with a large anticyclone that had collided with the current. Despite one study focused on coastal boundary currents and the other focused on a major Western Boundary Current extension, the complex horizontal structures seen through seismic imaging are tied to the processes of thermal intrusions and interleaving in both systems. Seismic Oceanography provides a unique capability of tracking the fine-scale horizontal extent of these intrusions

Rotor redesign for a highly loaded 1800 ft/sec tip speed fan. 3: Laser Doppler velocimeter report

Laser Doppler velocimeter (LDV) techniques were employed for testing a highly loaded, 550 m/sec (1800 ft/sec) tip speed, test fan stage, the objective to provide detailed mapping of the upstream, intrablade, and downstream flowfields of the rotor. Intrablade LDV measurements of velocity and flow angle were obtained along four streamlines passing through the leading edge at 45%, 69%, 85%, and 95% span measured from hub to tip, at 100% of design speed, peak efficiency; 100% speed, near surge; and 95% speed, peak efficiency. At the design point, most passages appeared to have a strong leading edge shock, which moved forward with increasing strength near surge and at part speeds. The flow behind the shock was of a complex mixed subsonic and supersonic form. The intrablade flowfields were found to be significantly nonperiodic at 100% design speed, peak efficiency

Effects of Olfactory Sense on Chocolate Craving

Chocolate has been referred to as one of the most socially acceptable addictions. It is one of America’s most craved foods, and women tend to crave it more frequently than men. Kemps and Tiggemann (2013) conducted an innovative experiment to reconcile the ideas of mental imagery, scent, and craving. After presenting images of sweet foods and having female undergraduate students smell a neutral scent, the researchers found that the neutral smell decreased craving for sweet foods. In the present study, researchers sought to replicate many aspects of Kemps and Tiggemann’s design. This new study went one step further, though: in addition to anticipating that a neutral or fresh scent would reduce one’s craving level, there was also an anticipation that smelling a sweet scent would increase craving levels. To test the research hypothesis, female undergraduate students received three smell conditions (no scent, fresh scent, and sweet scent) in the experiment. The order of the three conditions was counterbalanced. In all conditions, the students were shown a series of 12 images of chocolate food (cakes, muffins, ice cream, and brownies) on a large projector screen. Each image appeared for five seconds and was followed by an eight second retention period, during which participants were instructed to smell one of the essential oils. The students inhaled Slique essential oil in the fresh scent condition, inhaled vanilla essential oil in the sweet scent condition, and inhaled no essential oil in the control condition. After inhaling the scent, the students were asked to rate their craving level for the food just presented in the image on a 100 mm visual analogue scale. An analysis based on the 93 participants’ craving responses revealed a significant effect of the olfactory conditions, (F=73.813, p\u3c.001). That is, the students’ level of craving for chocolate food was higher in the sweet scent condition (M=59.31, SD=4.85), but lower in the fresh scent condition (M=34.65, SD=4.79), compared to the control condition (M=46.97, SD=6.67). These findings are important for a variety of populations including practitioners, nutritionists, and individuals seeking to curb their cravings or lose weight

A Qualitative Assessment of Military Kids: Instabilities & Constants

In the present study, we addressed the following research question: Do college-aged military kids report similar patterns in affect, behavior, and cognition due to shared perceptions and experiences? The study was conducted through semi-structured qualitative research interviews on a selective, Midwest, private college campus. Participants were asked questions regarding their upbringing as a military child and were asked to identify any potential connections between their past experiences and their current beliefs and behaviors. We report qualitative findings relating to themes in the areas of family dynamics, adaptability, and lifestyles

Natural functionally-graded composites in hard-to-soft tissue (bone- tendon) junctions

Composite materials are often functionally engineered to imbue desired mechanical properties in materials for structural applications. Nature has long engaged in such composite engineering of biological organisms, which has evolved in both flora and fauna in response to specific mechanical demands. Incorporation of phenolic compounds (like lignin) in stiffening cell assemblies in plant basts, or of silica in plant leaves to resist chomping insect incursions, are good examples in the plant world. Skeletal bone in vertebrates is the classic example in the animal kingdom, a composite of flexible fibrous polymerized organic protein and platy-crystalline inorganic mineral that results in a mechanically strong, hard, tough tissue. The musculo-skeletal system of vertebrates in fact comprises a variety of both hard and soft tissue types (bone, cartilage, tendon, ligament), generative cell types (osteoblasts, chondrocytes, tenocytes, fibroblasts, all of which can derive from multipotent mesenchymal stem cell precursors), and fibrous connective-tissue proteins (chiefly collagen, types I and II) that are susceptible to varying degrees of mineralization. In the case of bone, mineralization is extensive and forms a bi-continuous composite of mineral (chiefly partially-carbonated hydroxyapatite [Ca10(PO4,CO3)6(OH)2] and precursors) and collagen (a triple a-helix polypeptide) that self-assembles into protein fibrils (mostly type I collagen). Bone continually remodels itself and also re-forms as a consequence of injury or around implanted prostheses (such as knee and hip prostheses). High-resolution analytical TEM reveals [1] a mineralization mechanism which entails initial creation, at the mitochondria of bone-forming cells (osteoblasts), of pre-packaged vesicles that fill with a calcium-phosphate hydrogel and thereafter migrate through the cell wall. The vesicle contents subsequently crystallize [2] in the extra-cellular space with the dissolution of the vesicle containment wall, shortly before self-assembling collagen is expressed from the osteoblasts, providing a “just-in-time” ready source of Ca and P for mineralization of collagen fibrils with close to (though not identical with) the Ca/P ratio of hydroxyapatite found in the mature bone composite. The critical connective junctions between different tissue types in the musculo-skeletal system (bone, cartilage, tendon, muscle, ligament) involve several hard-tissue/soft-tissue interfaces, characterized by gradients in mineralization, cell type, cell morphology, and collagen self-assembly modes. For example, standard procedure for re-attachment of ruptured tendons—by surgically re-locating the tendon proximally to bone—re-establishes the important bone-tendon junction (enthesis) in a period of about one year. The process proceeds through growth, contiguous to the (fully mineralized) bone surface, of a partially-mineralized fibrocartilage layer (comprising collagen, expressed by chondrocyte cells, that self-assembles into principally Type II and Type X collagens). TEM [3] of ovine models shows that mineralization of this cartilaginous layer appears to occur via the identical mechanism established [1,2] for bone mineralization but initiated instead by chondrocyte cells. SEM [3] reveals that the cell-type in the remaining unmineralized cartilage portion gradually morphs into tenocytes, which form more elastic tendon fibers comprising, again, mostly Type I collagen (but also Types III, IV, V and IX self-assembly motifs). The resulting hard-tissue/soft-tissue enthesis junction is thus seen [3] to be a multiply graded interface involving three different cell types, several different collagen self-assembly motifs, and the functional gradation of a composite material paradigm spanning fully-hard tissue (bone) to fully-soft tissue (tendon). [1] S. Boonrungsiman, E. Gentleman, R. Carzaniga, N.D. Evans, D.W. McComb, A. E. Porter and M.M. Stevens, PNAS 109 (2012) 141. [2] V. Benezra, L. W. Hobbs and M. Spector, Biomaterials 23 (2001) 725; A. E. Porter, L. W. Hobbs, V. Benezra and M. Spector, Biomaterials 23 (2001) 921. [3] L. W. Hobbs, H. Wang, W. M. Reese, B. M. Tomerline, T. Y. C. Lim, A. E. Porter, M. Walton and M. J. Cotton, Microscopy & Microanalysis 19 (2013) 182

A Bayesian parameter estimation approach to pulsar time-of-arrival analysis

The increasing sensitivities of pulsar timing arrays to ultra-low frequency (nHz) gravitational waves promises to achieve direct gravitational wave detection within the next 5-10 years. While there are many parallel efforts being made in the improvement of telescope sensitivity, the detection of stable millisecond pulsars and the improvement of the timing software, there are reasons to believe that the methods used to accurately determine the time-of-arrival (TOA) of pulses from radio pulsars can be improved upon. More specifically, the determination of the uncertainties on these TOAs, which strongly affect the ability to detect GWs through pulsar timing, may be unreliable. We propose two Bayesian methods for the generation of pulsar TOAs starting from pulsar "search-mode" data and pre-folded data. These methods are applied to simulated toy-model examples and in this initial work we focus on the issue of uncertainties in the folding period. The final results of our analysis are expressed in the form of posterior probability distributions on the signal parameters (including the TOA) from a single observation.Comment: 16 pages, 4 figure

Effects of Olfactory Sense on Chocolate Craving

In the present study, we assessed the effect of the olfactory sense on chocolate craving in college females. Building on previous research by Kemps and Tiggemann (2013), we hypothesized that a fresh scent would decrease one’s craving level for chocolate food. While the precursor study only addressed the decrease of chocolate craving, we also hypothesized that a sweet scent would increase one’s craving level for chocolate foods. In the present experiment, participants rated their craving levels after viewing images of chocolate foods and inhaling essential oils: one fresh (Slique™ essence), and one sweet (vanilla). Results supported both of the hypotheses: inhaling a fresh scent reduced females’ craving levels; similarly, when a sweet scent was inhaled, the participants’ craving levels for chocolate food increased. These findings are particularly beneficial for women seeking weight loss and the findings can be applied in contexts such as weight loss programs, therapy, and maintenance programs, even beyond college settings. The results are particularly useful for helping women regarding stimuli that might serve as triggers for chocolate cravings

On detection of the stochastic gravitational-wave background using the Parkes pulsar timing array

We search for the signature of an isotropic stochastic gravitational-wave background in pulsar timing observations using a frequency-domain correlation technique. These observations, which span roughly 12 yr, were obtained with the 64-m Parkes radio telescope augmented by public domain observations from the Arecibo Observatory. A wide range of signal processing issues unique to pulsar timing and not previously presented in the literature are discussed. These include the effects of quadratic removal, irregular sampling, and variable errors which exacerbate the spectral leakage inherent in estimating the steep red spectrum of the gravitational-wave background. These observations are found to be consistent with the null hypothesis, that no gravitational-wave background is present, with 76 percent confidence. We show that the detection statistic is dominated by the contributions of only a few pulsars because of the inhomogeneity of this data set. The issues of detecting the signature of a gravitational-wave background with future observations are discussed.Comment: 12 pages, 8 figures, 7 tables, accepted for publication in MNRA