An analysis of the case records at the Boston University speech clinic from 1948 through 1950

Thesis (Ed.M.)--Boston Universit

Computer-Generated Holographic Optical Tweezer Arrays

Holographic techniques significantly extend the capabilities of laser tweezing, making possible extended trapping patterns for manipulating large numbers of particles and volumes of soft matter. We describe practical methods for creating arbitrary configurations of optical tweezers using computer-generated diffractive optical elements. While the discussion focuses on ways to create planar arrays of identical tweezers, the approach can be generalized to three-dimensional arrangements of heterogeneous tweezers and extended trapping patterns.Comment: 8 pages, 9 Postscript figures, REVTeX source. For related materials, see http://griergroup.uchicago.edu/~grier

Mangroves as a sustainable coastal defence

Mangroves effectively reduce the height of wind and swell waves over short distances (less than 500 m),\ud and can reduce storm surge water levels over greater distances (several kilometres of mangroves). Thus mangroves can\ud contribute to coastal defence strategies. However, their appropriate use depends on a thorough understanding of the\ud conditions under which they can provide these coastal defence services. Here we present a literature review of this\ud topic. Small wind and swell waves can be reduced in height by between 50 and 100% over 500 m of mangroves. Wave\ud reduction largely depends on water depth and vegetation structure and density. However, few measurements are\ud available for the reduction of bigger waves (> 70 cm in height) in deeper water (> 2 m). Storm surge water levels may\ud be reduced by between 5 cm and 50 cm per kilometre of mangrove, based on field measurements and validated\ud numerical models; water level reduction rates depend on the distance from the edge of the mangrove and the forward\ud speed of the cyclone, amongst other factors. Extreme events may severely damage or destroy mangroves, reducing their\ud effectiveness as a coastal defence. The use of mangroves in hybrid engineering can reduce flood risk: for example, a\ud mangrove foreshore in front of a sea wall/dyke will reduce wave impacts on the wall/dyke. The likelihood of waves\ud overtopping the sea wall or walls being breached is thus reduced, with an associated reduction in sea defence\ud maintenance costs. Therefore mangroves can contribute to coastal risk reduction, alongside other risk reduction\ud measures such as sea walls/dykes, early warning systems and evacuation plans. Additionally, mangroves can respond\ud dynamically to rising sea levels, in some cases maintaining their surface elevation with respect to local sea level; thus\ud they may act as a sustainable coastal defence in the face of rising sea levels and changing climatic patterns

Cortical bony thickening of the lateral intercondylar wall : the functional attachment of the anterior cruciate ligament

Background: The anatomy of the anterior cruciate ligament (ACL) has become the subject of much debate. There has been extensive study into attachment points of the native ligament, especially regarding the femoral attachment. Some of these studies have suggested that fibers in the ACL are of differing functional importance. Fibers with higher functional importance would be expected to exert larger mechanical stress on the bone. According to Wolff’s law, cortical thickening would be expected in these areas. Purpose: To examine cortical thickening in the region of the ACL footprint (ie, the functional footprint of the ACL). Study Design: Descriptive laboratory study. Methods: Using micro–computed tomography with resolutions ranging from 71 to 91 μm, the cortical thickness of the lateral wall of the intercondylar notch in 17 cadaveric knees was examined, along with surface topography. After image processing, the relationship between the cortical thickening and surface topology was visually compared. Results: A pattern of cortical thickening consistent with the functional footprint of the ACL was found. On average, this area was 3 times thicker than the surrounding bone and significantly thicker than the remaining lateral wall (P < .0001). This thickening was roughly elliptical in shape (with a mean centroid at 23.5 h:31 t on a Bernard and Hertel grid) and had areas higher on the wall where greater thickness was present. The relationship to previously reported osseous landmarks was variable, although the patterns were broadly consistent with those reported in previous studies describing direct and indirect fibers of the ACL. Conclusion: The findings of this study are consistent with those of recent studies describing fibers in the ACL of differing functional importance. The area in which the thickening was found has been defined and is likely to represent the functional footprint of the ACL

Light pollution is associated with earlier tree budburst across the United Kingdom

ArticleThe ecological impact of night-time lighting is of concern because of its well-demonstrated effects on animal behaviour. However, the potential of light pollution to change plant phenology and its corresponding knock-on effects on associated herbivores are less clear. Here, we test if artificial lighting can advance the timing of budburst in trees. We took a UK-wide 13 year dataset of spatially referenced budburst data from four deciduous tree species and matched it with both satellite imagery of night-time lighting and average spring temperature. We find that budburst occurs up to 7.5 days earlier in brighter areas, with the relationship being more pronounced for later-budding species. Excluding large urban areas from the analysis showed an even more pronounced advance of budburst, confirming that the urban ‘heat-island’ effect is not the sole cause of earlier urban budburst. Similarly, the advance in budburst across all sites is too large to be explained by increases in temperature alone. This dramatic advance of budburst illustrates the need for further experimental investigation into the impact of artificial night-time lighting on plant phenology and subsequent species interactions. As light pollution is a growing global phenomenon, the findings of this study are likely to be applicable to a wide range of species interactions across the world.R.S.-Y. was supported by a GWR-ESF Studentship awarded by the University of Exeter to R.H.f.-C. The study was also founded by a BBSRC grant to R.H.f-C

Pyrenoid loss impairs carbon-concentrating mechanism induction and alters primary metabolism in Chlamydomonas reinhardtii

Carbon-concentrating mechanisms (CCMs) enable efficient photosynthesis and growth in CO2-limiting environments, and in eukaryotic microalgae localisation of Rubisco to a microcompartment called the pyrenoid is key. In the model green alga Chlamydomonas reinhardtii, Rubisco preferentially relocalises to the pyrenoid during CCM induction and pyrenoid-less mutants lack a functioning CCM and grow very poorly at low CO2. The aim of this study was to investigate the CO2 response of pyrenoid-positive (pyr+) and pyrenoid-negative (pyr–) mutant strains to determine the effect of pyrenoid absence on CCM induction and gene expression. Shotgun proteomic analysis of low-CO2-adapted strains showed reduced accumulation of some CCM-related proteins, suggesting that pyr– has limited capacity to respond to low-CO2 conditions. Comparisons between gene transcription and protein expression revealed potential regulatory interactions, since Rubisco protein linker (EPYC1) protein did not accumulate in pyr– despite increased transcription, while elements of the LCIB/LCIC complex were also differentially expressed. Furthermore, pyr− showed altered abundance of a number of proteins involved in primary metabolism, perhaps due to the failure to adapt to low CO2. This work highlights two-way regulation between CCM induction and pyrenoid formation, and provides novel candidates for future studies of pyrenoid assembly and CCM function

Anthelmintic tolerance in free-living and facultative parasitic isolates of Halicephalobus (Panagrolaimidae)

Studies on anthelmintic resistance in equine parasites do not include facultative parasites. Halicephalobus gingivalis is a free-living bacteriovorous nematode and a known facultative parasite of horses with a strong indication of some form of tolerance to common anthelmintic drugs. This research presents the results of an in vitro study on the anthelmintic tolerance of several isolates of Halicephalobus to thiabendazole and ivermectin using an adaptation of the Micro-Agar Larval Development Test hereby focusing on egg hatching and larval development. Panagrellus redivivus and Panagrolaimus superbus were included as a positive control. The results generally show that the anthelmintic tolerance of Halicephalobus to both thiabendazole and ivermectin was considerably higher than that of the closely related Panagrolaimidae and, comparing to other studies, than that of obligatory equine parasites. Our results further reveal a remarkable trend of increasing tolerance from fully free-living isolates towards horse-associated isolates. In vitro anthelmintic testing with free-living and facultative parasitic nematodes offers the advantage of observing drug effect on the complete lifecycle as opposed to obligatory parasites which can only be followed until the third larval stage. We therefore propose Halicephalobus gingivalis as an experimental tool to deepen our understanding of the biology of anthelmintic tolerance

Comparison and Mapping Facilitate Relation Discovery and Predication

Relational concepts play a central role in human perception and cognition, but little is known about how they are acquired. For example, how do we come to understand that physical force is a higher-order multiplicative relation between mass and acceleration, or that two circles are the same-shape in the same way that two squares are? A recent model of relational learning, DORA (Discovery of Relations by Analogy; Doumas, Hummel & Sandhofer, 2008), predicts that comparison and analogical mapping play a central role in the discovery and predication of novel higher-order relations. We report two experiments testing and confirming this prediction