118 research outputs found

    ALEKS Constructs as Predictors of High School Mathematics Achievement for Struggling Students

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    Educators in the United States (U.S.) are increasingly turning to intelligent tutoring systems (ITS) to provide differentiated math instruction to high school students. However, many struggling high school learners do not perform well on these platforms, which reinforces the need for more awareness about effective supports that influence the achievement of learners in these milieus. The purpose of this study was to determine what factors of the Assessment and Learning in Knowledge Spaces (ALEKS), an ITS, are predictive of struggling learners\u27 performance in a blended-learning Algebra 1 course at an inner city technical high school located in the northeastern U.S. The theoretical framework consisted of knowledge base theory, the zone of proximal development, and cognitive learning theory. Three variables (student retention, engagement time, and the ratio of topics mastered to topics practiced) were used to predict the degree of association on the criterion variable (mathematics competencies), as measured by final course progress grades in algebra, and the Preliminary Scholastic Assessment Test (PSATm) math scores. A correlational predictive design was applied to assess the data of a purposive sample of 265 struggling students at the study site; multiple regression analysis was also used to investigate the predictability of these variables. Findings suggest that engagement time and the ratio of mastered to practiced topics were significant predictors of final course progress grades. Nevertheless, these factors were not significant contributors in predicting PSATm score. Retention was identified as the only statistically significant predictor of PSATm score. The results offer educators with additional insights that can facilitate improvements in mathematical content knowledge and promote higher graduation rates for struggling learners in high school mathematics

    Animal community dynamics at senescent and active vents at the 9° N East Pacific Rise after a volcanic eruption

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Gollner, S., Govenar, B., Arbizu, P. M., Mullineaux, L. S., Mills, S., Le Bris, N., Weinbauer, M., Shank, T. M., & Bright, M. Animal community dynamics at senescent and active vents at the 9° N East Pacific Rise after a volcanic eruption. Frontiers in Marine Science, 6, (2020): 832, doi:10.3389/fmars.2019.00832.In 2005/2006, a major volcanic eruption buried faunal communities over a large area of the 9°N East Pacific Rise (EPR) vent field. In late 2006, we initiated colonization studies at several types of post eruption vent communities including those that either survived the eruption, re-established after the eruption, or arisen at new sites. Some of these vents were active whereas others appeared senescent. Although the spatial scale of non-paved (surviving) vent communities was small (several m2 compared to several km2 of total paved area), the remnant individuals at surviving active and senescent vent sites may be important for recolonization. A total of 46 meio- and macrofauna species were encountered at non-paved areas with 33 of those species detected were also present at new sites in 2006. The animals living at non-paved areas represent refuge populations that could act as source populations for new vent sites directly after disturbance. Remnants may be especially important for the meiofauna, where many taxa have limited or no larval dispersal. Meiofauna may reach new vent sites predominantly via migration from local refuge areas, where a reproductive and abundant meiofauna is thriving. These findings are important to consider in any potential future deep-sea mining scenario at deep-sea hydrothermal vents. Within our 4-year study period, we regularly observed vent habitats with tubeworm assemblages that became senescent and died, as vent fluid emissions locally stopped at patches within active vent sites. Senescent vents harbored a species rich mix of typical vent species as well as rare yet undescribed species. The senescent vents contributed significantly to diversity at the 9°N EPR with 55 macrofaunal species (11 singletons) and 74 meiofaunal species (19 singletons). Of these 129 species associated with senescent vents, 60 have not been reported from active vents. Tubeworms and other vent megafauna not only act as foundation species when alive but provide habitat also when dead, sustaining abundant and diverse small sized fauna.We received funding from the Austrian FWF (GrantP20190-B17; MB), the U.S. National Science Foundation (OCE-0424953; to LM, D. McGillicuddy, A. Thurnherr, J. Ledwell, and W. Lavelle; and OCE-1356738 to LM), and the European Union Seventh Framework Programme (FP7/2007-2013) under the MIDAS project, Grant Agreement No. 603418. Ifremer and CNRS (France) supported NL cruise participation and sensor developments. BG was supported by a postdoctoral fellowship from the Deep Ocean Exploration Institute at WHOI (United States). TS was supported by the U.S. National Science Foundation (OCE-0327261 to TS and OCE-0937395 to TS and BG)

    Structural basis of proton-coupled potassium transport in the KUP family

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    Potassium homeostasis is vital for all organisms, but is challenging in single-celled organisms like bacteria and yeast and immobile organisms like plants that constantly need to adapt to changing external conditions. KUP transporters facilitate potassium uptake by the co-transport of protons. Here, we uncover the molecular basis for transport in this widely distributed family. We identify the potassium importer KimA from Bacillus subtilis as a member of the KUP family, demonstrate that it functions as a K+/H+ symporter and report a 3.7 Å cryo-EM structure of the KimA homodimer in an inward-occluded, trans-inhibited conformation. By introducing point mutations, we identify key residues for potassium and proton binding, which are conserved among other KUP proteins

    Facial correlates of emotional behaviour in the domestic cat (Felis catus)

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    Leyhausen’s (1979) work on cat behaviour and facial expressions associated with offensive and defensive behaviour is widely embraced as the standard for interpretation of agonistic behaviour in this species. However, it is a largely anecdotal description that can be easily misunderstood. Recently a facial action coding system has been developed for cats (CatFACS), similar to that used for objectively coding human facial expressions. This study reports on the use of this system to describe the relationship between behaviour and facial expressions of cats in confinement contexts without and with human interaction, in order to generate hypotheses about the relationship between these expressions and underlying emotional state. Video recordings taken of 29 cats resident in a Canadian animal shelter were analysed using 1-0 sampling of 275 4-second video clips. Observations under the two conditions were analysed descriptively using hierarchical cluster analysis for binomial data and indicated that in both situations, about half of the data clustered into three groups. An argument is presented that these largely reflect states based on varying degrees of relaxed engagement, fear and frustration. Facial actions associated with fear included blinking and half-blinking and a left head and gaze bias at lower intensities. Facial actions consistently associated with frustration included hissing, nose-licking, dropping of the jaw, the raising of the upper lip, nose wrinkling, lower lip depression, parting of the lips, mouth stretching, vocalisation and showing of the tongue. Relaxed engagement appeared to be associated with a right gaze and head turn bias. The results also indicate potential qualitative changes associated with differences in intensity in emotional expression following human intervention. The results were also compared to the classic description of “offensive and defensive moods” in cats (Leyhausen 1979) and previous work by Gourkow et al. (2014a) on behavioural styles in cats in order to assess if these observations had replicable features noted by others. This revealed evidence of convergent validity between the methods However, the use of CatFACS revealed elements relating to vocalisation and response lateralisation, not previously reported in this literature

    From planning to execution to the future: An overview of a concerted effort to enhance biological control in apple, pear, and walnut orchards in the western U.S.

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    We embarked on a large project designed to help enhance biological control in apple, pear and walnut orchards in the western U.S., where management programs were in the midst of a transition from older organo-phosphate insecticides to mating disruption and newer reduced-risk insecticides. A “pesticide replacement therapy” approach resulted in unstable management programs with unpredictable outbreaks of spider mites and aphids. Our project was designed to provide growers and pest managers with information on the effects of newer pesticide chemistries on a suite of representative natural enemies in both the laboratory and field, potential of new monitoring tools using herbivore-induced plant volatiles and floral volatiles, phenology of the key natural enemy species, economic consequences of using an enhanced biological control program, and value of an outreach program to get project outcomes into the hands of decision-makers. We present an overview of both the successes and failures of the project and of new projects that have spun off from this project to further enhance biological control in our systems in the near future

    Detecting the influence of initial pioneers on succession at deep-sea vents

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    © The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in PLoS One 7 (2012): e50015, doi:10.1371/journal.pone.0050015.Deep-sea hydrothermal vents are subject to major disturbances that alter the physical and chemical environment and eradicate the resident faunal communities. Vent fields are isolated by uninhabitable deep seafloor, so recolonization via dispersal of planktonic larvae is critical for persistence of populations. We monitored colonization near 9°50â€ČN on the East Pacific Rise following a catastrophic eruption in order to address questions of the relative contributions of pioneer colonists and environmental change to variation in species composition, and the role of pioneers at the disturbed site in altering community structure elsewhere in the region. Pioneer colonists included two gastropod species: Ctenopelta porifera, which was new to the vent field, and Lepetodrilus tevnianus, which had been rare before the eruption but persisted in high abundance afterward, delaying and possibly out-competing the ubiquitous pre-eruption congener L. elevatus. A decrease in abundance of C. porifera over time, and the arrival of later species, corresponded to a decrease in vent fluid flow and in the sulfide to temperature ratio. For some species these successional changes were likely due to habitat requirements, but other species persisted (L. tevnianus) or arrived (L. elevatus) in patterns unrelated to their habitat preferences. After two years, disturbed communities had started to resemble pre-eruption ones, but were lower in diversity. When compared to a prior (1991) eruption, the succession of foundation species (tubeworms and mussels) appeared to be delayed, even though habitat chemistry became similar to the pre-eruption state more quickly. Surprisingly, a nearby community that had not been disturbed by the eruption was invaded by the pioneers, possibly after they became established in the disturbed vents. These results indicate that the post-eruption arrival of species from remote locales had a strong and persistent effect on communities at both disturbed and undisturbed vents.The authors received funding from National Science Foundation grant OCE-0424953, WHOI Deep Ocean Exploration Institute, WHOI Summer Student Fellow program, Woods Hole Partnership in Education Program, IFREMER and CNRS, Fondation TOTAL Chair Extreme Marine Environment, Biodiversity and Global change

    ANTI-DIARRHEAL ACTIVITY OF ETHANOL AND CHLOROFORM SEED EXTRACT OF COLA NITIDA IN EXPERIMENTALLY INDUCED DIARRHEA

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    Objective: Cola nitida has been used in traditional medicine to treat diverse ailments including diarrhea. This study is carried out to investigate the antidiarrheal activity of the ethanol and chloroform seed extract of Cola nitida in Wistar albino rats. Methods: The ethanol and chloroform extracts of Cola nitida were evaluated with different doses (100mg/kg, 300mg/kg and 650mg/kg of animal weight) orally for antidiarrheal activity using castor oil induced-diarrhea, gastrointestinal motility test and castor oil-induced gastroenteropooling in Wistar albino rats. The observed activity was compared to standard antidiarrheal drug Lopermaide hydrochloride (2mg/kg) and to distilled water (10ml/kg) which served as the negative control. Results: Cola nitida ethanol extract at 150, 300 and 650mg/kg showed 55.64%, 59.73%, and 71.34% inhibition in gastrointestinal motility respectively. A significant reduction in diarrheal episodes (p<0.0001) was also observed with 650mg/kg of both extracts showing 100% inhibition. A reduction in the volume of fluid in the small intestine was also seen, this was however not significant. The chloroform extract of Cola nitida on the other hand produced a significant reduction in volume and weight of small intestinal content (p<0.05) with 650mg/kg showing a 92.73% inhibition of intestinal fluid accumulation. Conclusion: The ethanol and chloroform extract of Cola nitida showed anti-diarrheal activity in animal model by decreasing the frequency of defecation and by reducing gastrointestinal motility and intraluminal fluid accumulation in the intestine.                              Peer Review History: Received 15 October 2019;   Revised 31 October; Accepted 3 November, Available online 15 November 2019 Academic Editor: Dr. Ali Abdullah Al-yahawi, Al-Razi university, Department of Pharmacy, Yemen, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Prof. Dr. HĂŒsniye Kayalar, Ege University, Turkey, [email protected] Prof. Dr. Ali Gamal Ahmed Al-kaf, Sana'a university, Yemen, [email protected] Similar Articles: EPIDEMICITY OF VIBRIO CHOLERA IN SANA’A CITY, YEMEN: PREVALENCE AND POTENTIAL DETERMINANT

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    Sea ice diatom contributions to Holocene nutrient utilization in East Antarctica

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    Combined high-resolution Holocene ÎŽ30Sidiat and ÎŽ13Cdiat paleorecords are presented from theSeasonal Ice Zone, East Antarctica. Both data sets reïŹ‚ect periods of increased nutrient utilization by diatomsduring the Hypsithermal period (circa 7800 to 3500 calendar years (cal years) B.P.), coincident with a higherabundance of open water diatom species (Fragilariopsis kerguelensis), increased biogenic silica productivity(%BSi), and higher regional summer temperatures. The Neoglacial period (after circa 3500 cal years B.P.) isreïŹ‚ected by an increase in sea ice indicative species (Fragilariopsis curta and Fragilariopsis cylindrus,upto50%) along with a decrease in %BSi and ÎŽ13Cdiat(< 18‰ to 23‰). However, over this period, ÎŽ30Sidiatdata show an increasing trend, to some of the highest values in the Holocene record (average of +0.43‰).Competing hypotheses are discussed to account for the decoupling trend in utilization proxies including ironfertilization, species-dependent fractionation effects, and diatom habitats. Based on mass balance calculations,we highlight that diatom species derived from the semi-enclosed sea ice environment may have a confoundingeffect upon ÎŽ30Sidowncorecompositions of the seasonal sea ice zone. A diatom composition, with approximately28% of biogenic silica derived from the sea ice environment (diat-SI) can account for the increased averagecompo sition of ÎŽ30Sidiatduring the Neoglacial. These data highlight the signiïŹcant role sea ice diatoms can playwith relation to their export in sediment records, which has implications on productivity reconstructions fromthe seasonal ice zone

    The JWST Galactic Center Survey -- A White Paper

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    The inner hundred parsecs of the Milky Way hosts the nearest supermassive black hole, largest reservoir of dense gas, greatest stellar density, hundreds of massive main and post main sequence stars, and the highest volume density of supernovae in the Galaxy. As the nearest environment in which it is possible to simultaneously observe many of the extreme processes shaping the Universe, it is one of the most well-studied regions in astrophysics. Due to its proximity, we can study the center of our Galaxy on scales down to a few hundred AU, a hundred times better than in similar Local Group galaxies and thousands of times better than in the nearest active galaxies. The Galactic Center (GC) is therefore of outstanding astrophysical interest. However, in spite of intense observational work over the past decades, there are still fundamental things unknown about the GC. JWST has the unique capability to provide us with the necessary, game-changing data. In this White Paper, we advocate for a JWST NIRCam survey that aims at solving central questions, that we have identified as a community: i) the 3D structure and kinematics of gas and stars; ii) ancient star formation and its relation with the overall history of the Milky Way, as well as recent star formation and its implications for the overall energetics of our galaxy's nucleus; and iii) the (non-)universality of star formation and the stellar initial mass function. We advocate for a large-area, multi-epoch, multi-wavelength NIRCam survey of the inner 100\,pc of the Galaxy in the form of a Treasury GO JWST Large Program that is open to the community. We describe how this survey will derive the physical and kinematic properties of ~10,000,000 stars, how this will solve the key unknowns and provide a valuable resource for the community with long-lasting legacy value.Comment: This White Paper will be updated when required (e.g. new authors joining, editing of content). Most recent update: 24 Oct 202
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