UJI AKTIVITAS ANTIOKSIDAN EKSTRAK ETANOL SPONS Stylissa carteri DARI PULAU MENTEHAGE MINAHASA UTARA

ABSTRACTSponges are one of the animals from the phylum porifera and are marine invertebrates that live in coral reef ecosystems. Sponges are multi-cellular marine biota whose tissue and organ functions are very simple. Sponge Stylissa carteri can produce secondary metabolites from metabolic processes in the cells that exist in the body. This study aims to determine the antioxidant activity of the ethanolic extract of sponge Stylissa carteri from Mantehage Island, North Minahasa. Sponge Stylissa carteri was extracted by maceration method using ethanol as solvent. The antioxidant activity test was carried out using the DPPH method (1,1-diphenyl-2- picrylhydrazyl), which was measured by means of a UV-Vis spectrophotometer. The results of the study showed that the ethanolic extract of the sponge Stylissa carteri performed the antioxidant activity at each concentration, at a concentration of 0,5 mg/L (77,7 %), at a concentration 0,6 mg/L (86,13 %) and the highest was at a concentration of 0.7 mg/L with an inhibition value of 90.03%.Keywords: Antioxidant, DPPH, Stylissa carteri, MantehageABSTRAKSpons ialah salah satu spesies dari filum porifera juga merupakan invertebrata laut yang hidup pada ekosistem terumbu karang. Spons merupakan biota laut multi sel yang fungsi jaringan dan organnya sangat sederhana. Spons Stylissa carteri dapat menghasilkan metabolit sekunder dari proses metabolisme dalam sel yang ada pada tubuhnya. Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan dari ekstrak etanol spons Stylissa carteri dari pulau Mantehage, Minahasa Utara. Spons Stylissa carteri diekstrak dengan metode maserasi menggunakan pelarut etanol. Pengujian aktivitas antioksidan dilakukan dengan metode DPPH (1,1-difenil-2- pikrilhidrazil) yang diukur dengan alat spektrofotometer UV-Vis. Hasil dari penelitian menunjukan bahwa ekstrak etanol spons Stylissa carteri memiliki aktivitas antioksidan disetiap konsentrasi, Pada konsentrasi 0,5 mg/L (77,7 %), konsentrasi 0,6 mg/L (86,13 %) dan yang tertinggi pada konsentrasi 0,7 mg/L dengan nilai inhibisi 90,03%.Kata Kunci : Antioksidan, DPPH, Stylissa carteri, Mantehag

Constrained Emergence of Universals and Variation in Syllable Systems

A computational model of emergent syllable systems is developed based on a set of functional constraints on syllable systems and the assumption that language structure emerges through cumulative change over time. The constraints were derived from general communicative factors as well as from the phonetic principles of perceptual distinctiveness and articulatory ease. Through evolutionary optimization, the model generated mock vocabularies optimized for the given constraints. Several simulations were run to understand how these constraints might define the emergence of universals and variation in complex sound systems. The predictions were that (1) CV syllables would be highly frequent in all vocabularies evolved under the constraints; (2) syllables with consonant clusters, consonant codas and vowel onsets would occur much less frequently; (3) a relationship would exist between the number of syllable types in a vocabulary and the average word length in the vocabulary; (4) different syllable types would emerge according to, what we termed, an <EM iterative principle of syllable structure> and their frequency would be directly related to their complexity; and (5) categorical differences would emerge between vocabularies evolved under the same constraints. Simulation results confirmed these predictions and provided novel insights into why regularities and differences may occur across languages. Specifically, the model suggested that both language universals and variation are consistent with a set of functional constraints that are fixed relative to one another. Language universals reflect underlying constraints on the system and language variation represents the many different and equally-good solutions to the unique problem defined by these constraints

Investigating Metrical Context Effects on Anticipatory Coarticulation in Connected Speech Development

If rhythm acquisition is influenced by the development of articulatory timing, then metrical structure might be expected to condition this timing. This study tested this hypothesis by investigating anticipatory effects of an upcoming noun on the production of a preceding determiner, under the assumption that anticipatory coarticulation indexes chunking. Simple S-V-O sentences were elicited from 5-year-olds, 8-year-olds, and adults. The V was either monosyllabic packed or disyllabic patted. The O was a determiner phrase where nouns varied either in onset place-of-articulation (POA; tack vs. cat) or in their rhymes (tack vs. toot). Acoustic analyses of determiner schwa F1 and F2 showed no effect of verb on schwa coarticulation. Given other results, including an interaction between age group and POA, the findings suggest that the acquisition of articulatory timing is independent of metrical structure, even if this timing is related to speech rhythm acquisition

The New CGEMS - Preparing the Computer Graphics Educational Materials Source to Meet the Needs of Educators

ACM SIGGRAPH and Eurographics are restarting CGEMS, the Computer Graphics Educational Materials Source, an on-line repository of curricular material for computer graphics education. In this context, the question that we ask ourselves is: ''How can CGEMS best meet the needs of educators''? The aim of this forum is to provide the audience with an idea of the purpose of CGEMS - a source of educational materials for educators by educators - and to give them an opportunity to contribute their views and ideas towards shaping the new CGEMS. Towards this purpose, we have identified a number of issues to resolve, which the panel will put forward to the participants of the forum for discussion

Direct Numerical Simulation of a Weakly Stratified Turbulent Wake

Direct numerical simulation (DNS) is used to investigate a time-dependent turbulent wake evolving in a stably stratified background. A large initial Froude number is chosen to allow the wake to become fully turbulent and axisymmetric before stratification affects the spreading rate of the mean defect. The uncertainty introduced by the finite sample size associated with gathering statistics from a simulation of a time-dependent flow is reduced, compared to earlier simulations of this flow. The DNS reveals the buoyancy-induced changes to the turbulence structure, as well as to the mean-defect history and the terms in the mean-momentum and turbulence-kinetic-energy budgets, that characterize the various states of this flow - namely the three-dimensional (essentially unstratified), non-equilibrium (or 'wake-collapse') and quasi-two-dimensional (or 'two-component') regimes observed elsewhere for wakes embedded in both weakly and strongly stratified backgrounds. The wake-collapse regime is not accompanied by transfer (or 'reconversion') of the potential energy of the turbulence to the kinetic energy of the turbulence, implying that this is not an essential feature of stratified-wake dynamics. The dependence upon Reynolds number of the duration of the wake-collapse period is demonstrated, and the effect of the details of the initial/near-field conditions of the wake on its subsequent development is examined

Development of Aluminum LEKIDs for Balloon-Borne Far-IR Spectroscopy

We are developing lumped-element kinetic inductance detectors (LEKIDs) designed to achieve background-limited sensitivity for far-infrared (FIR) spectroscopy on a stratospheric balloon. The Spectroscopic Terahertz Airborne Receiver for Far-InfraRed Exploration (STARFIRE) will study the evolution of dusty galaxies with observations of the [CII] 158 $\mu$m and other atomic fine-structure transitions at $z=0.5-1.5$, both through direct observations of individual luminous infrared galaxies, and in blind surveys using the technique of line intensity mapping. The spectrometer will require large format ($\sim$1800 detectors) arrays of dual-polarization sensitive detectors with NEPs of $1 \times 10^{-17}$ W Hz$^{-1/2}$. The low-volume LEKIDs are fabricated with a single layer of aluminum (20 nm thick) deposited on a crystalline silicon wafer, with resonance frequencies of $100-250$ MHz. The inductor is a single meander with a linewidth of 0.4 $\mu$m, patterned in a grid to absorb optical power in both polarizations. The meander is coupled to a circular waveguide, fed by a conical feedhorn. Initial testing of a small array prototype has demonstrated good yield, and a median NEP of $4 \times 10^{-18}$ W Hz$^{-1/2}$.Comment: accepted for publication in Journal of Low Temperature Physic

Actin crosslinker competition and sorting drive emergent GUV size-dependent actin network architecture

The proteins that make up the actin cytoskeleton can self-assemble into a variety of structures. In vitro experiments and coarse-grained simulations have shown that the actin crosslinking proteins α-actinin and fascin segregate into distinct domains in single actin bundles with a molecular size-dependent competition-based mechanism. Here, by encapsulating actin, α-actinin, and fascin in giant unilamellar vesicles (GUVs), we show that physical confinement can cause these proteins to form much more complex structures, including rings and asters at GUV peripheries and centers; the prevalence of different structures depends on GUV size. Strikingly, we found that α-actinin and fascin self-sort into separate domains in the aster structures with actin bundles whose apparent stiffness depends on the ratio of the relative concentrations of α-actinin and fascin. The observed boundary-imposed effect on protein sorting may be a general mechanism for creating emergent structures in biopolymer networks with multiple crosslinkers

Evaluating Accomplished Teaching: Report of a Pilot Study into Means of Investigating the Impact of Accomplished Teaching on Pupils’ Learning in the Context of the Chartered Teacher Initiative in Scotland

No abstract available

Exploring the limits of saving a subspecies: The ethics and social dynamics of restoring northern white rhinos (Ceratotherium simum cottoni)

Abstract The northern white rhino (Ceratotherium simum cottoni) is functionally extinct with only two females left alive. However, cryopreserved material from a number of individuals represents the potential to produce additional individuals using advanced reproductive and genetic rescue technologies and perhaps eventually a population to return to their native range. If this could and were done, how should it be done responsibly and thoughtfully. What issues and questions of a technical, bioethical, and societal nature will it raise that need to be anticipated and addressed? Such issues are explored in this article by an interdisciplinary team assembled to provide context to the northern white rhino project of the San Diego Zoo Global

Measuring response functions of active materials from data

From flocks of birds to biomolecular assemblies, systems in which many individual components independently consume energy to perform mechanical work exhibit a wide array of striking behaviors. Methods to quantify the dynamics of these so called active systems generally aim to extract important length or time scales from experimental fields. Because such methods focus on extracting scalar values, they do not wring maximal information from experimental data. We introduce a method to overcome these limitations. We extend the framework of correlation functions by taking into account the internal headings of displacement fields. The functions we construct represent the material response to specific types of active perturbation within the system. Utilizing these response functions we query the material response of disparate active systems composed of actin filaments and myosin motors, from model fluids to living cells. We show we can extract critical length scales from the turbulent flows of an active nematic, anticipate contractility in an active gel, distinguish viscous from viscoelastic dissipation, and even differentiate modes of contractility in living cells. These examples underscore the vast utility of this method which measures response functions from experimental observations of complex active systems