838 research outputs found

    Proof of a conjecture on hadamard 2-groups

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    AbstractBy expanding on the results of James Davis, we prove by construction that every abelian 2-group that meets the exponent bound has a difference set

    Academic Assessment of English Learning School-Aged Children with Suspected Learning Disabilities

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    The investigators sought to determine whether education evaluators, mainly school psychologists, complied with federal, state, and professional practice guidelines when assessing English learning (EL) school-aged children suspected of a learning disability in three northern California school districts. In accordance with the Individuals with Disabilities Education Improvement Act (U.S. Congress, 2004), all intellectual and academic assessments must be selected and administered by properly trained assessors so as not to be racially, culturally, and linguistically inappropriate. The investigators reviewed the academic assessment reports of 88 EL children who, at the time of the study, had been receiving both special education as well as English as a Second Language instruction. We investigated the cumulative files to identify if evaluators consider the student’s primary language by using culturally appropriate tests and interpreters, communicating with families, and consideration other important factors such as their attendance, grades, sex, and other factors. The investigators discovered that out of the 88 children, 76 were assessed in English only although all spoke English as their second language. In addition, none of the school psychologists employed the use of an interpreter during any portion of the assessment process. Findings present a compelling case for greater university program and local in-service training on appropriate assessment procedures for school psychologists when assessing EL children for LD

    Insights into the decontamination of cocaine-positive hair samples

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    A highly discussed step in hair sample preparation for forensic analytics is the applied decontamination. The here presented investigations aim to gain insight and give recommendations on how to conduct this decontamination for the analysis of cocaine consumption in hair. Key insights were gained from the investigation of cocaine consumer hair, which was artificially contaminated in a humid atmosphere with 13C6 labelled cocaine and from cocaine powder contaminated hair. Several decontamination protocols were investigated, whereby the usage of a decontamination protocol consisting of multiple short repetitive washes allowed to visualize the wash-out of (13C6-) cocaine. Multiple methanol washes proved to be an efficient and simple decontamination approach. Our findings showed that decontamination protocols can successfully wash-out recent cocaine contaminations. They were observed to be rather quickly washed-out, whereas cocaine from consumption or “older” cocaine contaminations were shown to eliminate both at a constant rate (from inner hair compartments). Thus, the usage of decontamination protocols to differentiate between consumption and contamination was shown to be limited. As contamination can happen any time at any level, only the application of elaborated decision trees, based on cocaine metabolite ratios and thresholds, can provide the distinction between consumption and contamination. Thus, the authors highly recommend the usage of such tools on all hair samples analyzed for cocaine consumption

    Achilles tendon suture deteriorates tendon capillary blood flow with sustained tissue oxygen saturation – an animal study

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    <p>Abstract</p> <p>Background</p> <p>Treatment of ruptured Achilles tendons currently constitutes of conservative early functional treatment or surgical treatment either by open or minimal invasive techniques. We hypothesize that an experimental Achilles tendon suture in an animal model significantly deteriorates Achilles tendon microcirculation immediately following suturing.</p> <p>Methods</p> <p>Fifteen Achilles tendons of eight male Wistar rats (275–325 g) were included. After preparation of the Achilles tendon with a medial paratendinous approach, Achilles tendon microcirculation was assessed using combined Laser-Doppler and spectrophotometry (Oxygen-to-see) regarding:</p> <p indent="1">- tendinous capillary blood flow [arbitrary units AU]</p> <p indent="1">- tendinous tissue oxygen saturation [%]</p> <p indent="1">- tendinous venous filling pressure [rAU]</p> <p>The main body of the Achilles tendon was measured in the center of the suture with 50 Hz. 10 minutes after Achilles tendon suture (6-0 Prolene), a second assessment of microcirculatory parameters was performed.</p> <p>Results</p> <p>Achilles tendon capillary blood flow decreased by 57% following the suture (70 ± 30 AU vs. 31 ± 16 AU; p < 0.001). Tendinous tissue oxygen saturation remained at the same level before and after suture (78 ± 17% vs. 77 ± 22%; p = 0.904). Tendinous venous filling pressure increased by 33% (54 ± 16 AU vs. 72 ± 20 AU; p = 0.019) after suture.</p> <p>Conclusion</p> <p>Achilles tendon suture in anaesthetised rats causes an acute loss of capillary perfusion and increases postcapillary venous filling pressures indicating venous stasis. The primary hypothesis of this study was confirmed. In contrast, tendinous tissue oxygen saturation remains unchanged excluding acute intratendinous hypoxia within the first 10 minutes after suture. Further changes of oxygen saturation remain unclear. Furthermore, it remains to be determined to what extent reduced capillary blood flow as well as increased postcapillary stasis might influence tendon healing from a microcirculatory point of view in this animal setting.</p

    Multi-Component Evaluation to Minimize the Spread of Aquatic Invasive Seaweeds, Harmful Algal Bloom Microalgae, and Invertebrates via the Live Bait Vector in Long Island Sound

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    The goal of the project was to protect guard Long Island Sound from the introduction of non-native organisms that may be imported via fishing bait worms and the seaweed packing material known as wormweed (Ascophyllum nodosum). The project examined bait for non-native invertebrate animals, macroalgae (also known as seaweeds), and harmful, toxin-producing microalgae. Bait was purchased from retail bait shops at locations ranging from northeastern Long Island Sound along the Connecticut shoreline to the southwestern part of the Sound in Long Island. Using a combination of visual and microscopic inspection, and sophisticated molecular biological techniques to detect the presence of microalgal cells, the study questioned whether (i) non-native organisms were being imported via bait worms, and if so whether; (ii) non-native organisms vary according to purchase location, or; (iii) time of year. Overall, 14 species of macroalgae, two species of harmful microalgae (Alexandrium fundyense, and Pseudo-nitzschia multiseries), and 23 different categories of invertebrate animals were discovered among the wormweed. Only one of the microalgal species was not native to Long Island Sound. Overall, location (eastern vs. western, northern vs. southern Long Island Sound) did not affect the number of algal or invertebrate species. Temperature did affect algal diversity and abundance, however, both in post-collection incubation (5° \u3c 15° = 25°) and seasonally (summer produced highest numbers). Invertebrates were most abundant in summer as well. The Gulf of Maine now harbors a diverse suite of non-native organisms. These may be exported to other areas of the U.S. via national bait wholesalers and cause ecological harm to the receiving ecosystem. In addition to potential ecological impacts associated with the import of non-native organisms, economic harm is also possible. For example, commercial shellfishing beds may be closed when harmful microalgae bloom in coastal waters. With ca. 470 retail bait shops in NY and CT, the chances of introduction of harmful non-natives is not trivial. For example, in our 18 month study of four locations, we discovered the harmful non-native microalga Pseudo-nitzschia multiseries in 58% of our samples

    Joseph\u27s Jogger

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    Joseph Cornelius is a young man with spastic quadriplegia who loves the experience of being in triathlons. He actively participates in triathlons in which he is pushed in a jogger. His old jogger has become worn out and does not dampen road impacts which cause Joseph discomfort. Thus, the scope of this project was to create a new stroller in which he can be pushed efficiently for long distances and that dampens road impacts in order to allow Joseph to continue enjoying triathlons
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