An Examination of Six “Nutting Stones” from East Texas for Plant Phytoliths

In this article we report on an examination of six nutting stones from East Texas sites as well as an exploratory examination of their possible functions. “Nutting stones” have long been presumed to have been used prehistorically for crushing nuts such as hickory, etc. as foodstuffs. In fact Davis described them as being: A small flat stone, usually made of limestone, sandstone or other sedimentary types of rock which could be carried by hand. The flat surface may have one or more ground or pecked cups of various sizes, shapes and depth. It is postulated that they were used for various purposes such as cracking nuts, mixing pigments, milling herbs and seeds, or as an anvil for flint knapping. While Davis is an avocationalist and numerous professional archaeologists have dealt with nutting stones, we know of neither a more complete definition nor any other effort to empirically test for their function

Biological Characteristics and Fishery Assessment of Alaska Plaice, Pleuronectes quadrituberculatus, in the Eastern Bering Sea

Alaska plaice, Pleuronectes quadrituberculatus, is one of the major flatfishes in the eastern Bering Sea ecosystem and is most highly concentrated in the shallow continental shelf of the eastern Bering Sea. Annual commercial catches have ranged from less than 1,000 metric tons (t) in 1963 to 62,000 t in 1988. Alaska plaice is a relatively large flatfish averaging about 32 cm in length and 390 g in weight in commercial catches. They are distributed from nearshore waters to a depth of about 100 m in the eastern Bering Sea during summer, but move to deeper continental shelf waters in winter to escape sea ice and cold water temperatures. Being a long-lived species (>30 years), they have a relatively low natural mortality rate estimated at 0.20. Maturing at about age 7, Alaska plaice spawn from April through June on hard sandy substrates of the shelf region, primarily around the 100 m isobath. Prey items primarily include polychaetes and other marine worms. In comparison with other flatfish, Alaska plaice and rock sole, Pleuronectes bilineatus, have similar diets but different habitat preferences with separate areas of peak population density which may minimize interspecific competition. Yellowfin sole, Pleuronectes asper, while sharing similar habitat, differs from these two species because of the variety of prey items in its diet. Competition for food resources among the three species appears to be low. The resource has experienced light exploitation since 1963 and is currently in good condition. Based on the results of demersal trawl surveys and age-structured analyses, the exploitable biomass increased from 1971 through the mid-1980’s before decreasing to the 1997 level of 500,000 t. The recommended 1998 harvest level, Allowable Biological Catch, was calculated from the Baranov catch equation based on the FMSY harvest level and the projected 1997 biomass, resulting in a commercial harvest of 69,000 t, or about 16% of the estimated exploitable biomass

Multifractal analysis of Birkhoff averages for countable Markov maps

In this paper we prove a multifractal formalism of Birkhoff averages for interval maps with countably many branches. Furthermore, we prove that under certain regularity assumptions on the potential the Birkhoff spectrum is real analytic. Applications of these results to number theory are also given. Finally, we compute the Hausdorff dimension of the set of points for which the Birkhoff average is infinite.Comment: 27 pages. Substantial changes have been made to Theorem 1.2 and sections 4,5 and 6. Some minor corrections have been made elsewher

The effect of stromal hydration on surgical outcomes for cataract patients who received a hydrogel ocular bandage

Thomas R WaltersTexan Eye, Austin, TX, USAPurpose: The purpose of this study was to examine the effect of stromal hydration on surgical outcomes for patients who received the new hydrogel ocular bandage (ReSure™ Adherent Ocular Bandage, Ocular Therapeutix, Inc, Bedford, MA, USA) following routine cataract surgery.Methods: This post-hoc, single-masked study was conducted with 310 patients who were scheduled to undergo unilateral clear corneal cataract surgery with phacoemulsification and intraocular lens implantation. Incisions were closed with stromal hydration (270 patients) or without stromal hydration (40 patients) based on physician standard of care. All patients received the hydrogel bandage at the conclusion of the procedure. Ocular assessments of stromal edema, flare, corneal staining, anterior chamber cells, best-corrected visual acuity, and intraocular pressure were made 24 hours after surgery.Results: Significantly more patients experienced stromal edema in the group with stromal hydration (26.3% versus 10.0%, respectively; P = 0.028). A higher percentage of patients experienced corneal staining when stromal hydration was performed (20.4% versus 2.5%; P = 0.004). The mean BCVA (best-corrected visual acuity) also was significantly different between the groups (logMAR of 0.164 with stromal hydration versus 0.095 without hydration; P = 0.007). No significant differences were observed between the study groups in terms of flare, anterior chamber cells, or intraocular pressure.Conclusion: Cataract surgery without stromal hydration provided better surgical outcomes than the traditional hydration procedure when used in conjunction with a new hydrogel bandage.Keywords: cataract surgery, hydrogel bandage, phacoemulsification, stromal hydratio

Auditory-based processing of communication sounds

This thesis examines the possible benefits of adapting a biologically-inspired model of human auditory processing as part of a machine-hearing system. Features were generated by an auditory model, and used as input to machine learning systems to determine the content of the sound. Features were generated using the auditory image model (AIM) and were used for speech recognition and audio search. AIM comprises processing to simulate the human cochlea, and a ‘strobed temporal integration’ process which generates a stabilised auditory image (SAI) from the input sound. The communication sounds which are produced by humans, other animals, and many musical instruments take the form of a pulse-resonance signal: pulses excite resonances in the body, and the resonance following each pulse contains information both about the type of object producing the sound and its size. In the case of humans, vocal tract length (VTL) determines the size properties of the resonance. In the speech recognition experiments, an auditory filterbank was combined with a Gaussian fitting procedure to produce features which are invariant to changes in speaker VTL. These features were compared against standard mel-frequency cepstral coefficients (MFCCs) in a size-invariant syllable recognition task. The VTL-invariant representation was found to produce better results than MFCCs when the system was trained on syllables from simulated talkers of one range of VTLs and tested on those from simulated talkers with a different range of VTLs. The image stabilisation process of strobed temporal integration was analysed. Based on the properties of the auditory filterbank being used, theoretical constraints were placed on the properties of the dynamic thresholding function used to perform strobe detection. These constraints were used to specify a simple, yet robust, strobe detection algorithm. The syllable recognition system described above was then extended to produce features from profiles of the SAI and tested with the same syllable database as before. For clean speech, performance of the features was comparable to that of those generated from the filterbank output. However when pink noise was added to the stimuli, performance dropped more slowly as a function of signal-to-noise ratio when using the SAI-based AIM features, than when using either the filterbank-based features or the MFCCs, demonstrating the noise-robustness properties of the SAI representation. The properties of the auditory filterbank in AIM were also analysed. Three models of the cochlea were considered: the static gammatone filterbank, dynamic compressive gammachirp (dcGC) and the pole-zero filter cascade (PZFC). The dcGC and gammatone are standard filterbank models, whereas the PZFC is a filter cascade, which more accurately models signal propagation in the cochlea. However, while the architecture of the filterbanks is different, they have all been successfully fitted to psychophysical masking data from humans. The abilities of the filterbanks to measure pitch strength were assessed, using stimuli which evoke a weak pitch percept in humans, in order to ascertain whether there is any benefit in the use of the more computationally efficient PZFC. Finally, a complete sound effects search system using auditory features was constructed in collaboration with Google research. Features were computed from the SAI by sampling the SAI space with boxes of different scales. Vector quantization (VQ) was used to convert this multi-scale representation to a sparse code. The ‘passive-aggressive model for image retrieval’ (PAMIR) was used to learn the relationships between dictionary words and these auditory codewords. These auditory sparse codes were compared against sparse codes generated from MFCCs, and the best performance was found when using the auditory features

Large Protein Folding and Dynamics Studied by Advanced Hydrogen Exchange Methods

Protein folding studies over the past 50 years have been largely focused on small proteins (\u3c 200 residues) leading to a dearth of information about large protein folding. Regardless of protein size, research has generally lacked the structural tools with necessary temporal resolution to provide mechanistic insight into the process. This goal requires incisive information on transient kinetic intermediate conformations that describe the folding pathway. In this work special challenges that hinder large protein folding studies are addressed, and advancements to both HX NMR and HX MS experiments are described that provide unparalleled temporal resolution of structure formation than has been previously possible. These various advanced hydrogen exchange methods are used to study folding behaviors of the large, 370-residue, two-domain maltose binding protein from E. coli and provide a description of its folding pathway in structural detail. This work sheds light on two basic unresolved problems regarding the mechanisms of protein folding, the first being the enigmatic nature of the initial folding collapse event seen in many proteins, and the second concerning the nature of the folding pathway. We find that from an initially heterogeneous hydrophobic collapse, an obligatory intermediate emerges with a 7-second time constant followed by an apparent sequential pathway to the native state. These results add the largest protein studied at structural resolution to-date to the list of proteins known to fold through obligatory, native-like intermediates in distinct pathways and this work highlights strategies that may be employed to interrogate other large systems in future work

Environmental Controls on the Diversity and Distribution of Endosymbionts Associated with \u3ci\u3ePhacoides pectinatus\u3c/i\u3e (Bivalvia: Lucinidae) from Shallow Mangrove and Seagrass Sediments, St. Lucie County, Florida

Lucinid bivalves are capable of colonizing traditionally inhospitable shallow marine sediments due to metabolic functions of bacterial endosymbionts located within their gills. Because lucinids can often be the dominant sediment infauna, defining their roles in sediment and pore fluid geochemical cycling is necessary to address concerns related to changes in coastal biological diversity and to understanding the sensitivity of threatened coastal ecosystems over time. However, there has been limited research done to understand the diversity and distribution of many lucinid chemosymbiotic systems. Therefore, the goals of this thesis were to evaluate the distribution of Phacoides pectinatus and its endosymbiont communities from Ft. Pierce, St. Lucie County, Florida, and to define the environmental controls on potential free-living P. pectinatus endosymbionts to understand symbiont distribution patterns and host acquisition. Nearly all of the encountered P. pectinatus hosts were confined to within one meter of mangrove canopy. The distribution of P. pectinatus correlated to concentrations of organic carbon in the sediments, but not to total dissolved sulfide or sea grass vegetation densities. Sequencing of bacterial 16S rRNA genes from sediment and pore fluids from the P. pectinatus habitat revealed that Proteobacteria dominated the communities, including Alpha-, Delta-, and Gammaproteobacteria classes. Other major phyla included the Bacteroidetes, Chloroflexi, Planctomycetes, and Spirochaetes. 16S rRNA genes for both P. pectinatus gills and feet were closely related to novel bacterial communities comprised of Sedimenticola, Kistimonas, Methylomarinum, and Spirochaeta spp., as well as unclassified Rickettsiales (Alphaproteobacteria) and unclassified Lentisphaerae. This level of potential endosymbiont diversity has not been previously reported for lucinids. Moreover, potential endosymbiont populations differed by lucinid location, as gills containing higher Rickettsiales occurred in areas with the lowest clam density and gills in deeper sediments contained a higher proportion of Methylomarinum. Despite broad sediment and pore water bacterial diversity, no environmental sequences genetically matched those from P. pectinatus at the genus level. These results, while strengthening our understanding of a lucinid-symbiont system, still highlight how limited our knowledge is about these systems. These results provide new directions for future research and can be used to help understand how sensitive these systems are to environmental change

Supporting Conservation: The Roles of Flagship Species and Identifiable Victims

Psychological insights into human behaviour can have enormous applied value for promoting charitable giving. Nevertheless, the application of these insights to conservation appeals featuring non-human animals has scarcely been explored. Although people often donate more when presented with single 'identifiable' victims, whether this effect also extends to non-humans is not known. Similarly, although many conservation appeals feature flagship species, it is unclear whether flagship species generate increased donations. We experimentally investigated how (i) identifiable versus statistical beneficiaries and (ii) flagship versus non-flagship species affected donations to a conservation charity. Unexpectedly, subjects did not donate more when presented with single identifiable beneficiaries rather than groups of beneficiaries. Flagship species, on the other hand, increased donation amounts relative to appeals featuring non-flagship species. We discuss how these findings can inform and improve the effectiveness of conservation fundraising appeals

Assessing the potential impact of strengthening food safety regulations on developing countries: The US Food Safety and Modernization Act

This paper’s goal is to assess the extent to which producers in Developing Countries have coped stricter US food safety regulations. We approach the question by calculating refusals/imports ratios and their trends for a sample of Developing Countries. We conclude there is a learning process in low value added products.food safety, traceability, value chain analysis, trade, Latin America and the Caribbean, Food Consumption/Nutrition/Food Safety, International Development, International Relations/Trade,

Who Benefits from KIPP?

The nation's largest charter management organization is the Knowledge is Power Program (KIPP). KIPP schools are emblematic of the No Excuses approach to public education, a highly standardized and widely replicated charter model that features a long school day, an extended school year, selective teacher hiring, strict behavior norms, and a focus on traditional reading and math skills. No Excuses charter schools are sometimes said to focus on relatively motivated high achievers at the expense of students who are most diffiult to teach, including limited English proficiency (LEP) and special education (SPED) students, as well as students with low baseline achievement levels. We use applicant lotteries to evaluate the impact of KIPP Academy Lynn, a KIPP school in Lynn, Massachusetts that typifies the KIPP approach. Our analysis focuses on special needs students that may be underserved. The results show average achievement gains of 0.36 standard deviations in math and 0.12 standard deviations in reading for each year spent at KIPP Lynn, with the largest gains coming from the LEP, SPED, and low-achievement groups. The average reading gains are driven almost completely by SPED and LEP students, whose reading scores rise by roughly 0.35 standard deviations for each year spent at KIPP Lynn.human capital, charter schools, achievement