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This article argues that language teaching would benefit by paying attention to the L2 user rather than concentrating primarily on the native speaker. It suggests ways in which language teaching can apply an L2 user model and exploit the students' L1. Because L2 users differ from monolingual native speakers in their knowledge of their L2s and Lls and in some of their cognitive processes, they should be considered as speakers in their own right, not as approximations to monolingual native speakers. In the classroom, teachers can recognise this status by incorporating goals based on L2 users in the outside world, bringing L2 user situations and roles into the classroom, deliberately using the students' L1 in teaching activities, and looking to descriptions of L2 users or L2 learners rather than descriptions of native speakers as a source of information. The main benefits of recognising that L2 users are speakers in the own right, however, will come from students' and teachers' having a positive image of L2 users rather than seeing them as failed native speakers. Language professionals often take for granted that the only appropriate models of a language's use come from its native speakers. Linguists look at the intuitions of native speakers or collect quantities of their speech; language teachers encourage students to be like native speakers. This article argues that the prominence of the native speaker in language teaching has obscured the distinctive nature of the successful L2 user and created an unattainable goal for L2 learners. It recommends that L2 users be viewed as multicompetent language users rather than as deficient native speakers and suggests how language teaching can recognise students as L2 users both in and out of the classroom.

The control factors controlling the growth of native silicon oxide on silicon (Si) surfaces have been identified. The coexistence of oxygen and water or moisture is required for growth of native oxide both in air and in ultrapure water at room temperature. Layer-by-layer growth of native oxide films occurs on Si surfaces exposed to air. Growth of native oxides on n-Si in ultrapure water is described by a parabolic law, while the native oxide film thickness on n+-Si in ultrapure water saturates at 10 Å. The native oxide growth on n-Si in ultrapure water is continuously accompanied by a dissolution of Si into the water and degrades the atomic flatness at the oxide-Si interface, producing a rough oxide surface. A dissolution of Si into the water has not been observed for the Si wafer having surface covered by the native oxide grown in air. Native oxides grown in air and in ultrapure de-ionized water have been demonstrated experimentally to exhibit remarkable differences such as contact angles of ultrapure water drops and chemical binding energy. These chemical bond structures for native oxide films grown in air and in ultrapure water are also discussed.

Ecosystem services are critical to human survival; in selected cases, maintaining these services provides a powerful argument for conserving biodiversity. Yet, the ecological and economic underpinnings of most services are poorly understood, impeding their conservation and management. For centuries, farmers have imported colonies of European honey bees (Apis mellifera) to fields and orchards for pollination services. These colonies are becoming increasingly scarce, however, because of diseases, pesticides, and other impacts. Native bee communities also provide pollination services, but the amount they provide and how this varies with land management practices are unknown. Here, we document the individual species and aggregate community contributions of native bees to crop pollination, on farms that varied both in their proximity to natural habitat and management type (organic versus conventional). On organic farms near natural habitat, we found that native bee communities could provide full pollination services even for a crop with heavy pollination requirements (e.g., watermelon, Citrullus lanatus), without the intervention of managed honey bees. All other farms, however, experienced greatly reduced diversity and abundance of native bees, resulting in insufficient pollination services from native bees alone. We found that diversity was essential for sustaining the service, because of year-to-year variation in community composition. Continued degradation of the agro-natural landscape will destroy this "free" service, but conservation and restoration of bee habitat are potentially viable economic alternatives for reducing dependence on managed honey bees.

Natively unfolded or intrinsically unstructured proteins constitute a unique group of the protein kingdom. The evolutionary persistence of such proteins represents strong evidence in the favor of their importance and raises intriguing questions about the role of protein disorders in biological processes. Additionally, natively unfolded proteins, with their lack of ordered structure, represent attractive targets for the biophysical studies of the unfolded polypeptide chain under physiological conditions in vitro. The goal of this study was to summarize the structural information on natively unfolded proteins in order to evaluate their major conformational characteristics. It appeared that natively unfolded proteins are characterized by low overall hydrophobicity and large net charge. They possess hydrodynamic properties typical of random coils in poor solvent, or premolten globule conformation. These proteins show a low level of ordered secondary structure and no tightly packed core. They are very flexible, but may adopt relatively rigid conformations in the presence of natural ligands. Finally, in comparison with the globular proteins, natively unfolded polypeptides possess 'turn out' responses to changes in the environment, as their structural complexities increase at high temperature or at extreme pH.

Abstract The idea that a new generation of students is entering the education system has excited recent attention among educators and education commentators. Termed ‘digital natives’ or the ‘Net generation’, these young people are said to have been immersed in technology all their lives, imbuing them with sophisticated technical skills and learning preferences for which traditional education is unprepared. Grand claims are being made about the nature of this generational change and about the urgent necessity for educational reform in response. A sense of impending crisis pervades this debate. However, the actual situation is far from clear. In this paper, the authors draw on the fields of education and sociology to analyse the digital natives debate. The paper presents and questions the main claims made about digital natives and analyses the nature of the debate itself. We argue that rather than being empirically and theoretically informed, the debate can be likened to an academic form of a ‘moral panic’. We propose that a more measured and disinterested approach is now required to investigate ‘digital natives’ and their implications for education.

Implicit solvation models provide, for many applications, a reasonably accurate and computationally effective way to describe the electrostatics of aqueous solvation. Here, a popular analytical Generalized Born (GB) solvation model is modified to improve its accuracy in calculating the solvent polarization part of free energy changes in large-scale conformational transitions, such as protein folding. In contrast to an earlier GB model (implemented in the AMBER-6 program), the improved version does not overstabilize the native structures relative to the finite-difference Poisson-Boltzmann continuum treatment. In addition to improving the energy balance between folded and unfolded conformers, the algorithm (available in the AMBER-7 and NAB molecular modeling packages) is shown to perform well in more than 50 ns of native-state molecular dynamics (MD) simulations of thioredoxin, protein-A, and ubiquitin, as well as in a simulation of Barnase/Barstar complex formation. For thioredoxin, various combinations of input parameters have been explored, such as the underlying gas-phase force fields and the atomic radii. The best performance is achieved with a previously proposed modification to the torsional potential in the Amber ff99 force field, which yields stable native trajectories for all of the tested proteins, with backbone root-mean-square deviations from the native structures being approximately 1.5 A after 6 ns of simulation time. The structure of Barnase/Barstar complex is regenerated, starting from an unbound state, to within 1.9 A relative to the crystal structure of the complex.

Abstract This work corroborates the hierarchical conceptual model for soil aggregate structure presented by Tisdall and Oades (1982), extends it to North American grassland soils, and elaborates on the aspects relating to the influence of cultivation upon losses of soil organic matter. Aggregate size distributions observed for our soils are very similar to those of Australian soils, indicating that the microaggregate‐macroaggregate model may hold for a wide array of grassland soils from around the world. The use of two wetting treatments prior to sieving demonstrated that the native sod soil had the same general structural characteristics as cultivated soil but the macroaggregates were more stable. When slaked, native and cultivated soil present in the microaggregate size classes had less organic C, N, and P than the soil remaining as macroaggregates, even when expressed on a sand‐free basis. Moreover, the C/N, C/P, and N/P ratios of microaggregates were narrower than those of macroaggregate size classes. Much more C and N was lost than P under the conditions of this study. Element‐specific differences in microbial catabolic processes vs. extracellular enzyme activity and its attendant feedback controls are postulated to account for this difference. When the macroaggregates were crushed to the size of microaggregates, mineralizable C as a percent of the total organic C was generally greater for macro‐ than microaggregates early in the incubation for the cultivated soil and throughout most of the incubation for the native sod soil. Mineralizable N as a percent of the total organic N was greatest in macroaggregates even when the macroaggregates were not crushed. The macroaggregate‐micraggregate conceptual model is applied to help explain accumulation of soil organic matter under native conditions and its loss upon cultivation.

"Natively unfolded" proteins occupy a unique niche within the protein kingdom in that they lack ordered structure under conditions of neutral pH in vitro. Analysis of amino acid sequences, based on the normalized net charge and mean hydrophobicity, has been applied to two sets of proteins: small globular folded proteins and "natively unfolded" ones. The results show that "natively unfolded" proteins are specifically localized within a unique region of charge-hydrophobicity phase space and indicate that a combination of low overall hydrophobicity and large net charge represent a unique structural feature of "natively unfolded" proteins.

Linguistic input probably has to be comprehensible to the learner if it is to serve as data for second language acquisition. It is widely assumed that input becomes comprehensible through the speech modifications of native speakers addressing non-native speakers of the target language. Recent research on native speaker/non-native speaker conversation suggests, however, that modifications of the interactional structure of conversation are more important in this regard. They are more extensive and more consistently observed than input modifications, and often occur when the latter do not. Fifteen devices for the modification of interaction are described. They are of three kinds: strategies, which serve to avoid conversational trouble, tactics, which are used to repair the discourse when trouble occurs, and strategies and tactics, devices which serve both functions.

"This book presents a theoretical discussion of problems and issues encountered in the Native American community from a perspective that accepts Native knowledge as legitimate. Native American cosmology and metaphor are used extensively in order to deal with specific problems such as alcoholism, suicide, family, and community problems. The authors discuss what it means to present material from the perspective of a people who have legitimate ways of knowing and conceptualizing reality and show that it is imperative to understand intergenerational trauma and internalized oppression in order to understand the issues facing Native Americans today."--pub. website.

What leads humans to divide the social world into groups, preferring their own group and disfavoring others? Experiments with infants and young children suggest these tendencies are based on predispositions that emerge early in life and depend, in part, on natural language. Young infants prefer to look at a person who previously spoke their native language. Older infants preferentially accept toys from native-language speakers, and preschool children preferentially select native-language speakers as friends. Variations in accent are sufficient to evoke these social preferences, which are observed in infants before they produce or comprehend speech and are exhibited by children even when they comprehend the foreign-accented speech. Early-developing preferences for native-language speakers may serve as a foundation for later-developing preferences and conflicts among social groups.

Generational differences are seen as the cause of wide shifts in our ability to engage with technologies and the concept of the digital native has gained popularity in certain areas of policy and practice. This paper provides evidence, through the analysis of a nationally representative survey in the UK, that generation is only one of the predictors of advanced interaction with the Internet. Breadth of use, experience, gender and educational levels are also important, indeed in some cases more important than generational differences, in explaining the extent to which people can be defined as a digital native. The evidence provided suggests that it is possible for adults to become digital natives, especially in the area of learning, by acquiring skills and experience in interacting with information and communication technologies. This paper argues that we often erroneously presume a gap between educators and students and that if such a gap does exist, it is definitely possible to close it.

This paper builds upon the research investigating conversational interactions between native speakers (NS) and non-native speakers (NNS) by focusing on interactions among non-native speakers. We examine NS/NS, NS/NNS, and NNS/NNS conversations, noting that negotiation of meaning is most prevalent among NNS/ NNS pairs. We propose an explanation for this phenomenon and set up a model to describe it in terms of ‘pushdowns’ from and ‘pops’ to the main discourse. Finally, we suggest the importance of NNS/NNS conversation and especially the function of negotiation in second language acquisition.

MOTIVATION: Computational annotation of protein coding genes in genomic DNA is a widely used and essential tool for analyzing newly sequenced genomes. However, current methods suffer from inaccuracy and do poorly with certain types of genes. Including additional sources of evidence of the existence and structure of genes can improve the quality of gene predictions. For many eukaryotic genomes, expressed sequence tags (ESTs) are available as evidence for genes. Related genomes that have been sequenced, annotated, and aligned to the target genome provide evidence of existence and structure of genes. RESULTS: We incorporate several different evidence sources into the gene finder AUGUSTUS. The sources of evidence are gene and transcript annotations from related species syntenically mapped to the target genome using TransMap, evolutionary conservation of DNA, mRNA and ESTs of the target species, and retroposed genes. The predictions include alternative splice variants where evidence supports it. Using only ESTs we were able to correctly predict at least one splice form exactly correct in 57% of human genes. Also using evidence from other species and human mRNAs, this number rises to 77%. Syntenic mapping is well-suited to annotate genomes closely related to genomes that are already annotated or for which extensive transcript evidence is available. Native cDNA evidence is most helpful when the alignments are used as compound information rather than independent positionwise information. AVAILABILITY: AUGUSTUS is open source and available at http://augustus.gobics.de. The gene predictions for human can be browsed and downloaded at the UCSC Genome Browser (http://genome.ucsc.edu).

We have performed a comprehensive first-principles investigation of native point defects in ZnO based on density functional theory within the local density approximation (LDA) as well as the $\mathrm{LDA}+U$ approach for overcoming the band-gap problem. Oxygen deficiency, manifested in the form of oxygen vacancies and zinc interstitials, has long been invoked as the source of the commonly observed unintentional $n$-type conductivity in ZnO. However, contrary to the conventional wisdom, we find that native point defects are very unlikely to be the cause of unintentional $n$-type conductivity. Oxygen vacancies, which have most often been cited as the cause of unintentional doping, are deep rather than shallow donors and have high formation energies in $n$-type ZnO (and are therefore unlikely to form). Zinc interstitials are shallow donors, but they also have high formation energies in $n$-type ZnO and are fast diffusers with migration barriers as low as $0.57\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$; they are therefore unlikely to be stable. Zinc antisites are also shallow donors but their high formation energies (even in Zn-rich conditions) render them unlikely to be stable under equilibrium conditions. We have, however, identified a different low-energy atomic configuration for zinc antisites that may play a role under nonequilibrium conditions such as irradiation. Zinc vacancies are deep acceptors and probably related to the frequently observed green luminescence; they act as compensating centers in $n$-type ZnO. Oxygen interstitials have high formation energies; they can occur as electrically neutral split interstitials in semi-insulating and $p$-type materials or as deep acceptors at octahedral interstitial sites in $n$-type ZnO. Oxygen antisites have very high formation energies and are unlikely to exist in measurable concentrations under equilibrium conditions. Based on our results for migration energy barriers, we calculate activation energies for self-diffusion and estimate defect-annealing temperatures. Our results provide a guide to more refined experimental studies of point defects in ZnO and their influence on the control of $p$-type doping.

The first generation of Digital Nativeschildren who were born into and raised in the digital worldare coming of age, and soon our world will be reshaped in their image. Our economy, our politics, our culture, and even the shape of our family life will be forever transformed. But who are these Digital Natives? And what is the world theyre creating going to look like?In Born Digital, leading Internet and technology experts John Palfrey and Urs Gasser offer a sociological portrait of these young people, who can seem, even to those merely a generation older, both extraordinarily sophisticated and strangely narrow. Exploring a broad range of issues, from the highly philosophical to the purely practical, Born Digital will be essential reading for parents, teachers, and the myriad of confused adults who want to understand the digital presentand shape the digital future.

The Story Began Long Ago... I. Commitment from the Mirror-Writing Box The triple bind Silence in time Rites of passage The Guilt Freedom and the masses For the people, by the people, and from the people Vertically imposed language: on clarity, craftsmanship, and She who steals language A sketched window on the world The infinite play of empty mirrors Writing woman II. The Language of Nativism: Anthropology as a Scientific Conversation of Man with Man The reign of worn codes The positivist dream: We, the natives They, the natives A Western Science of man A Myth of mythology What OmanO and which OmanO? Gossip and science: a conversation on what I love according to truth Nativist interpretation See them as they see each other III. Difference: OA Special Third World Women IssueO The Policy of Oseparate developmentO The Sense of specialness The question of roots and authenticity Infinite Layer: I am not i can be you and me The female identity enclosure Third World? OWomanO and the subtle power of linguistic exclusion Subject-in-the-making Ethnicity or womanhood: whose duality? The Gender controversy IV. GrandmaOs Story Truth and fact: story and history Keepers and transmitters Storytelling in the OcivilizedO context A regenerating force At once OblackO and OwhiteO magic The woman warrior: she who breaks open the spell A cure and a protection from illness OTell it the way they tell itO OThe story must be told. There must not be any lieO Notes Selected Bibliography Index

The experimental material accumulated in the literature on the conformational behavior of intrinsically unstructured (natively unfolded) proteins was analyzed. Results of this analysis showed that these proteins do not possess uniform structural properties, as expected for members of a single thermodynamic entity. Rather, these proteins may be divided into two structurally different groups: intrinsic coils, and premolten globules. Proteins from the first group have hydrodynamic dimensions typical of random coils in poor solvent and do not possess any (or almost any) ordered secondary structure. Proteins from the second group are essentially more compact, exhibiting some amount of residual secondary structure, although they are still less dense than native or molten globule proteins. An important feature of the intrinsically unstructured proteins is that they undergo disorder-order transition during or prior to their biological function. In this respect, the Protein Quartet model, with function arising from four specific conformations (ordered forms, molten globules, premolten globules, and random coils) and transitions between any two of the states, is discussed.

This article uses 1990 census data to study the effects of immigrant inflows on occupation‐specific labor market outcomes. I find that intercity mobility rates of natives and earlier immigrants are insensitive to immigrant inflows. However, occupation‐specific wages and employment rates are systematically lower in cities with higher relative supplies of workers in a given occupation. The results imply that immigrant inflows over the 1980s reduced wages and employment rates of low‐skilled natives in traditional gateway cities like Miami and Los Angeles by 1–3 percentage points.