首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Adaptive sample size methods have been a popular topic in the field of clinical trials. There are a few basic requirements for the adaptive methods to be acceptable from the international regulatory viewpoint. All valid methods need to control the overall type-I error rate at the pre-specified level. The rule of the interim and final decisions needs to be explicit and clearly documentable. It is extremely desirable that the method employed also provides estimation of the treatment effect in addition to the significance test. In this paper we describe the point and confidence interval estimation for the likelihood approach of sample-size adaptive design proposed by Li et al. (Biostatistics 3:277–287, 2002, J. Biopharm. Stat. 15:707–718, 2005). We use the median unbiased estimator (Cox and Hinkley, Theoretical Statistics, p. 273, 1974) for estimating the treatment effect and demonstrate that the estimator has small mean squared error compared to the naïve method, and that the confidence interval estimation has correct coverage probability.  相似文献   

2.
Recent studies of noncrystalline HIV-1 capsid protein (CA) assemblies by our laboratory and by Polenova and coworkers (Protein Sci 19:716–730, 2010; J Mol Biol 426:1109–1127, 2014; J Biol Chem 291:13098–13112, 2016; J Am Chem Soc 138:8538–8546, 2016; J Am Chem Soc 138:12029–12032, 2016; J Am Chem Soc 134:6455–6466, 2012; J Am Chem Soc 132:1976–1987, 2010; J Am Chem Soc 135:17793–17803, 2013; Proc Natl Acad Sci USA 112:14617–14622, 2015; J Am Chem Soc 138:14066–14075, 2016) have established the capability of solid state nuclear magnetic resonance (NMR) measurements to provide site-specific structural and dynamical information that is not available from other types of measurements. Nonetheless, the relatively high molecular weight of HIV-1 CA leads to congestion of solid state NMR spectra of fully isotopically labeled assemblies that has been an impediment to further progress. Here we describe an efficient protocol for production of segmentally labeled HIV-1 CA samples in which either the N-terminal domain (NTD) or the C-terminal domain (CTD) is uniformly 15N,13C-labeled. Segmental labeling is achieved by trans-splicing, using the DnaE split intein. Comparisons of two-dimensional solid state NMR spectra of fully labeled and segmentally labeled tubular CA assemblies show substantial improvements in spectral resolution. The molecular structure of HIV-1 assemblies is not significantly perturbed by the single Ser-to-Cys substitution that we introduce between NTD and CTD segments, as required for trans-splicing.  相似文献   

3.
We develop a Bayes factor-based approach for the design of non-inferiority clinical trials with a focus on controlling type I error and power. Historical data are incorporated in the Bayesian design via the power prior discussed in Ibrahim and Chen (Stat Sci 15:46–60, 2000). The properties of the proposed method are examined in detail. An efficient simulation-based computational algorithm is developed to calculate the Bayes factor, type I error, and power. The proposed methodology is applied to the design of a non-inferiority medical device clinical trial.  相似文献   

4.
In the planning stage of a clinical trial investigating a potentially targeted therapy, there is commonly a high degree of uncertainty whether the treatment is more efficient (or efficient only) in a subgroup compared to the whole population. Recently developed adaptive designs enable to allow for an efficacy assessment both for the whole population and a subgroup and to select the target population mid-course based on interim results (see, e.g., Wang et al., Pharm Stat 6:227–244, 2007, Brannath et al., Stat Med 28:1445–1463, 2009, Wang et al., Biom J 51:358–374, 2009, Jenkins et al., Pharm Stat 10:347–356, 2011, Friede et al., Stat Med 31:4309–4120, 2012). Frequently, predictive biomarkers are used in these trials for identifying patients more likely to benefit from a drug. We consider the situation that the selection of the patient population is based on a biomarker and where the diagnostics that evaluates the biomarker may be perfect, i.e., with 100 % sensitivity and specificity, or not. The performance of the applied subset selection rule is crucial for the overall characteristics of the design. In the setting of an adaptive enrichment design, we evaluate the properties of subgroup selection rules in terms of type I error rate and power by taking into account decision rules with a fixed ad hoc threshold and optimal decision rules developed for the situation of uncertain assumptions. In a simulation study, we demonstrate that designs with optimal decision rules are under certain assumptions more powerful as compared to those with ad hoc decision rules. Throughout the results, a strong impact of sensitivity and specificity of the biomarker on both type I error rate and power is observed.  相似文献   

5.
Neuroimaging data often take the form of high-dimensional arrays, also known as tensors. Addressing scientific questions arising from such data demands new regression models that take multidimensional arrays as covariates. Simply turning an image array into a vector would both cause extremely high dimensionality and destroy the inherent spatial structure of the array. In a recent work, Zhou et al. (J Am Stat Assoc, 108(502):540–552, 2013) proposed a family of generalized linear tensor regression models based upon the CP (CANDECOMP/PARAFAC) decomposition of regression coefficient array. Low-rank approximation brings the ultrahigh dimensionality to a manageable level and leads to efficient estimation. In this article, we propose a tensor regression model based on the more flexible Tucker decomposition. Compared to the CP model, Tucker regression model allows different number of factors along each mode. Such flexibility leads to several advantages that are particularly suited to neuroimaging analysis, including further reduction of the number of free parameters, accommodation of images with skewed dimensions, explicit modeling of interactions, and a principled way of image downsizing. We also compare the Tucker model with CP numerically on both simulated data and real magnetic resonance imaging data, and demonstrate its effectiveness in finite sample performance.  相似文献   

6.
Many multi-regional clinical trials are faced with possible heterogeneity in treatment effect among regions and consequently the interpretation of the trial results is quite challenging. Regional heterogeneity can be caused by the differences in intrinsic factors, extrinsic factors or trial/data quality among regions. An apparent regional difference in treatment effect can be caused by a play of chance or sampling variability. In another aspect, regional heterogeneity may have substantial ramifications on sample size estimation for planning a multi-regional trial, as stipulated in Hung et al. (Pharm Stat 9:173–178, 2010), Lan and Pinheiro (Stat Biosci 14:235–244, 2012) and Quan et al. (Stat Med 33:2191–2205, 2014). Analyses of multi-regional trials are commonly based on a fixed-effect model assuming that the true treatment effects in all regions are equal in magnitude which may or may not be practical. Random-effect modelling has been considered as an alternative to deal with regional heterogeneity. In this research work we shall discuss the statistical implications of the statistical modelling approaches on the type I error probability and statistical power associated with testing the global treatment effect. We also develop formulae to assess the probability that some regions may falsely show an apparent negative trend by chance or sampling variability. As another alternative, a fixed-effect model that accounts for acceptable regional heterogeneity will be introduced.  相似文献   

7.
In a famous experiment Stanley Miller showed that a large number of organic substances can emerge from sparking a mixture of methane, ammonia and hydrogen in the presence of water (Miller, Science 117:528–529, 1953). Among these substances Miller identified different amino acids, and he concluded that prebiotic events may well have produced many of Life’s molecular building blocks. There have been many variants of the original experiment since, including different gas mixtures (Miller, J Am Chem Soc 77:2351–2361, 1955; Oró Nature 197:862–867, 1963; Schlesinger and Miller, J Mol Evol 19:376–382, 1983; Miyakawa et al., Proc Natl Acad Sci 99:14,628–14,631, 2002). Recently some of Miller’s remaining original samples were analyzed with modern equipment (Johnson et al. Science 322:404–404, 2008; Parker et al. Proc Natl Acad Sci 108:5526–5531, 2011) and a total of 23 racemic amino acids were identified. To give an overview of the chemical variety of a possible prebiotic broth, here we analyze a “Miller type” experiment using state of the art mass spectrometry and NMR spectroscopy. We identify substances of a wide range of saturation, which can be hydrophilic, hydrophobic or amphiphilic in nature. Often the molecules contain heteroatoms, with amines and amides being prominent classes of molecule. In some samples we detect ethylene glycol based polymers. Their formation in water requires the presence of a catalyst. Contrary to expectations, we cannot identify any preferred reaction product. The capacity to spontaneously produce this extremely high degree of molecular variety in a very simple experiment is a remarkable feature of organic chemistry and possibly prerequisite for Life to emerge. It remains a future task to uncover how dedicated, organized chemical reaction pathways may have arisen from this degree of complexity.  相似文献   

8.
Using data collected over nearly three years of ethnographic fieldwork in the Gilgit-Baltistan region of northern Pakistan, my paper explores hospital spaces, clinical services and treatment encounters as conduits for the expression and propagation of conflictive Shia-Sunni sectarianism. Where my prior research has investigated the political etiologies (Hamdy in Am Ethnol 35(4):553–569, 2008) associated with Gilgiti women’s experiences of childbirth during ‘tensions’, as Shia-Sunni hostilities are locally known, this paper focuses on healthcare providers’ professional and personal navigations of an episode of conflict whose epicentre was at the District Headquarter Hospital, Gilgit-Baltistan’s foremost government hospital. Through critical evaluation of the impacts of Shia-Sunni tensions on the social, administrative and clinical practices and consequences of medicine, my paper analyses the complex ways that clinics in crisis serve as zones of contact (Pratt in Profession 91:33–40, 1991) and abandonment (Biehl in Soc Text 68(19):131–149, 2001; Subjectivity: ethnographic investigations, 2007), in which neglect and harm are directed along lines of sectarian affiliation to produce vulnerability, spectacular violence and death for healthcare providers and patients.  相似文献   

9.
This paper addresses the phenomenon of mixed paradigms, i.e. mixed perfective auxiliation systems, attested in a wide range of Italo-Romance varieties (cf. Loporcaro 2001, 2007a, 2014; Manzini and Savoia 2005, among others). In these varieties, two auxiliary verbs, esse and habere, alternate within one and the same (sub)paradigm, displaying various patterns which can range from morphosyntactically motivated to apparently unmotivated distributions (here termed ‘morphomic’). I propose that, in these varieties, auxiliary selection is no longer a syntactically driven phenomenon, but becomes morphologized. I draw on the notion of ‘lexical split’ (cf. Corbett 2013, 2015, 2016) and describe the attested splits induced by intraparadigmatic auxiliary alternation. Following Bonami (2015), I put forward a typology of such splits. It is shown that, apart from motivated distributions, some morphomic patterns can also be found. The typology becomes more complex insofar as patterns with free variation between both auxiliaries are taken into account, as well as patently morphomic patterns which also seem to display external syntactic relevance (cf. Corbett 2013: 174–176). The phenomena reviewed and discussed in this paper are of major interest because they demonstrate the existence of competing exponence strategies within periphrasis, thus enriching the notion of ‘possible lexeme’ (cf. Corbett 2015: 146).  相似文献   

10.
The problem of plant individuality is something which has vexed botanists throughout the ages, with fashion swinging back and forth from treating plants as communities of individuals (Darwin 1800; Braun and Stone 1853; Münch 1938) to treating them as organisms in their own right, and although the latter view has dominated mainstream thought most recently (Harper 1977; Cook 1985; Ariew and Lewontin 2004), a lively debate conducted mostly in Scandinavian journals proves that the issues are far from being resolved (Tuomi and Vuorisalo 1989b; Fagerström 1992; Pan and Price 2001). In this paper I settle the matter once and for all, by showing which elements of each side are correct.  相似文献   

11.
A systematic theoretical investigation on cobalt lithium clusters LinCo [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12] was performed with a DFT approach. The location of global minima and structural evolution were carried out using the partical swarm optimization method. Li6Co is the transition structure in going from low-coordinated structures to three-dimensional torispherical structures with a cobalt atom enclosed by lithium atoms. Maxima of ?2 E and E b for LinCo were found at n?=?3, 6, 8, 10, indicating that these clusters possess higher relative stability than their neighbors. In comparison with small clusters, n?=?1–6, the greater electron transfer from Li-2s to Co-3d within cage-like clusters LinCo (n?=?7–12) strengthens the bonding effect between Lin and Co, which is reflected in the Wiberg bond index of Co and atomic binding energy analysis. AdNDP analysis verified the presence of both Lewis bonding elements (1c–2e objects) and delocalized bonding elements (6c–2e, 9c–2e and 10c–2e bonds). It is hoped that this theoretical work will provide favorable information to help understand the influence of dopant transition metal atoms on the properties of lithium-based materials.  相似文献   

12.
Biomarker-directed targeted clinical trial is aimed at developing pharmaceutical agents for a targeted patient subpopulation sharing a specific disease etiology. Biomarker plays a key role in patient enrichment for targeted trials. Biomarker performance substantially impacts heterogeneity of a targeted study population and consequently trial efficiency, statistical power, information accumulation, and early stopping decision-making (Simon and Maitournam in Clinical Cancer Res 10:6759-6763, 2004; Maitournam and Simon in Stat Med 24:329-339, 2005; Gao et al. in Contemp Clin Trials 42:119-131, 2015). Hence, accurate assessment of biomarker performance is crucial to sample size calculation in planning of targeted trials. However, prior knowledge of biomarker performance is often limited at the planning stage due to inadequacy of biomarker validation, differences between study populations in demographic characteristics and trial settings, etc. Under this circumstance, adaptive design would be useful in updating biomarker performance and re-estimating sample sizes when a targeted trial is ongoing. In this paper, we propose a two-stage adaptive design that provides flexibility in biomarker performance-based sample size adaption for targeted trials. The design can facilitate a targeted trial to achieve planned statistical power by re-assessment of actual biomarker performance and subsequent sample size adaption while preserving desired type-1 error.  相似文献   

13.

Introduction

Despite much work over past decades, whether antigen-specific immune reactions occur in rheumatoid arthritis (RA) and to what extent such reactions are directed towards joint-specific autoantigens is still questionable. One strong indicator for antigenic involvement in RA is the fact that certain major histocompatibility complex (MHC) class II genotypes [human leucocyte antigen (HLA)-DR4 and HLA-DR1] predispose for the development of the disease [1]. In the present report, collagen type II (CII) was studied as a putative autoantigen on the basis of both clinical and experimental data that show an increased frequency of antibodies to CII in RA patients [2,3,4] and that show that CII can induce experimental arthritis [5].It is evident from the literature that RA peripheral blood mononuclear cells (PBMCs) respond poorly to antigenic stimulation [6,7,8], and in particular evidence for a partial tolerization to CII has been presented [9]. The strategy of the present work has accordingly been to reinvestigate T-cell reactivity to CII in RA patients, to relate it to the response to commonly used recall antigens and to analyze IFN-γ responses as an alternative to proliferative responses.  相似文献   

14.
This article presents a corpus study of over 16,000 tokens of -er nominalizations on 62 verbal bases that were extracted from the Corpus of Contemporary American English and the British National Corpus. We show that an individual -er nominal can often be given a range of modal and aspectual readings and that a number of factors influence the availability of different readings for -er nominals, including verb type, syntactic context (verb tenses, adverbs), and encyclopedic information. On the basis of these data, we argue, contra Cohen (2016), that the core meaning of the affix -er (as in writer, printer, etc.) cannot be that of a dynamic modal. We show that neither Cohen’s (2016) analysis nor syntactic analyses such as that of Alexiadou and Schäfer (2010) can account for the range of readings we find. We conclude by sketching one possible analysis in terms of the Lexical Semantic Framework of Lieber (2004, 2016) that postulates underspecified lexical representations of the -er nominals and resolution of underspecification in context.  相似文献   

15.

Objectives

In this review we compare the advantages and disadvantages of different model biological systems for determining the metabolic functions of cells in complex environments, how they may change in different disease states, and respond to therapeutic interventions.

Introduction

All preclinical drug-testing models have advantages and drawbacks. We compare and contrast established cell, organoid and animal models with ex vivo organ or tissue culture and in vivo human experiments in the context of metabolic readout of drug efficacy. As metabolism reports directly on the biochemical state of cells and tissues, it can be very sensitive to drugs and/or other environmental changes. This is especially so when metabolic activities are probed by stable isotope tracing methods, which can also provide detailed mechanistic information on drug action. We have developed and been applying Stable Isotope-Resolved Metabolomics to examine metabolic reprogramming of human lung cancer cells in monoculture, in mouse xenograft/explant models, and in lung cancer patients in situ (Lane et al. in Omics 15:173–182, 2011; Fan et al. in Metabolomics 7(2):257–269, 2011a, in Pharmacol Ther 133:366–391, 2012a, in Metabolomics 8(3):517–527, b; Xie et al. in Cell Metab 19:795–809, 2014; Ren et al. in Sci Rep 4:5414, 2014; Sellers et al. in J Clin Investig 125(2):687–698, 2015). We are able to determine the influence of the tumor microenvironment using these models. We have now extended the range of models to fresh human tissue slices, similar to those originally described by Warburg (Biochem Z 142:317–333, 1923), which retain the native tissue architecture and heterogeneity with a paired benign versus cancer design under defined cell culture conditions. This platform offers an unprecedented human tissue model for preclinical studies on metabolic reprogramming of human cancer cells in their tissue context, and response to drug treatment (Xie et al. 2014). As the microenvironment of the target human tissue is retained and individual patient’s response to drugs is obtained, this platform promises to transcend current limitations of drug selection for clinical trials or treatments

Conclusions

Development of ex vivo human tissue and animal models with humanized organs including bone marrow and liver show considerable promise for analyzing drug responses that are more relevant to humans. Similarly using stable isotope tracer methods with these improved models in advanced stages of the drug development pipeline, in conjunction with tissue biopsy is expected significantly to reduce the high failure rate of experimental drugs in Phase II and III clinical trials.
  相似文献   

16.
Multiple investigators have reported thepresence of defects in the immune response of the elderly [Castle In: Clin Infect Dis 31:578, 2000; Ortqvist et al. In: Eur Respir J 30:414–422, 2007; Saurwein-Teissl et al. In: J Immunol 168:5893, 2002; Haynes et al. In: Proc Natl Acad Sci USA 100:15053–15058, 2003]. These defects reduce the magnitude of the immune response to infection and to vaccination. In individuals greater than 55 years of age, the probability of developing a fully protective neutralizing antibody response to the yearly multivalent particle inactivated influenza vaccine is less than 20% [Jefferson et al. In: Lancet 264:1165–1174, 2005; Goodwin et al. In: Vaccine 24:1159–1169, 2006; Jackson et al. In: Lancet 372:398–405, 2008; Simonsen and Taylor In: Lancet 7:658–666, 2007]. The defects in the aged immune system that are responsible for this limited response to vaccination in the older age groups include functional defects of the antigen presenting cells, functional defects in CD4 helper CD4 T cells and monocytes, and an altered microenvironment [Eaton et al. In: J Exp Med 200:1613–1622, 2004; Dong et al. In: J Gen Virol 84:1623–1628, 2003; Deng et al. In: Immunology 172:3437–3446, 2004; Cella et al. In: J Exp Med 184:747–752, 1996]. Starting at puberty, the involution of the thymus and the consequent reduction of the export of naïve T cells specific to neo-antigens leads to the reduction of the ratio of antigen naïve to memory cells as chronological age advances [Prelog In: AutoimmunRev 5:136–139, 2006; McElhaney et al. In: J Immunology 176:6333–6339, 2006]. Changes in glycosylation of T cells and target antigens acquired during the aging process and the antibodies to these new glycopeptides and glycoproteins may also contribute to a reduction in the functioning of the adaptive immune response [Ishii et al. In: J Clin Neurosci 14:110–115, 2007; Shirai et al. In: Clin Exp Immunol 12:455–464, 1972; Adkins and Riley In: Mech AgeingDev 103:147–164, 1998; Ben-Yehuda and Weksler In: Cancer Investigation 10:525–531, 1992]. One of the more interesting examples of the functional defects in the cells of the adaptive immune response is a reduced level of expression in the surface cytoadhesion and activation receptor molecules on CD4 helper T cells undergoing activation during vaccination. Upon infection or vaccination, CD40L is typically increased on the surface of CD4 helper T cells during activation, and this increased expression is absolutely essential to the CD40L promotion of expansion of antigen-specific B cells and CD 8 effector T cells in response to infection or vaccination [Singh et al. In: Protein Sci 7:1124–1135, 1998; Grewal and Flavell In: Immunol Res 16: 59–70, 1997; Kornbluth In: J Hematother Stem Cell Res 11:787–801, 2002; Garcia de Vinuesa et al. In: Eur J Immunol 29:3216–3224, 1999]. In aged human beings and mice, the reduced levels of expression of CD40 ligand (CD40L) in activated CD4 helper T cells is dramatically reduced [Eaton et al. In: J Exp Med 200:1613–1622, 2004; Dong et al. In: J Gen Virol 84:1623–1628, 2003]. To circumvent the reduction in CD40L expression and the subsequent reduction in immune response in the elderly, we have developed a chimeric vaccine comprised of the CD40L linked to the target antigen, in a replication incompetent adenoviral vector and in booster protein. This review will discuss the implementation the potential use of this approach for the vaccination of the older populations for cancer and infection.  相似文献   

17.
Verb-noun compounds are typically considered to be one of the most important innovations in the domain of Romance word-formation (cf. Bauer 2011, among many others). This morphological innovation can also be seen as part of a general tendency in Romance languages to prefer head-initial structures across different levels of the language system (cf., e.g., Ledgeway 2012: 225). However, the question of the productivity of VN compounds arises immediately as there is evidence that the pattern has become extremely productive only recently. This paper investigates the question of the productivity of the VN compounds starting out with a distinction between availability of a word-formation pattern and its profitability (cf., e.g., Bauer 2001). This article shows that the structural presence—availability—of VN compounding seems to be diachronically constant, but that the quantitative exploitation of the pattern—its profitability—turns out to be a recent phenomenon. Following recent research on compounding in Spanish (Moyna 2011) and French (Rosenberg 2007, 2008, 2011), this paper takes one concrete example of the Italian VN compounds and proceeds to show its diachronic evolution from the 16th to the 19th century on the basis of data drawn from diachronic corpora as well as from major historical dictionaries. It demonstrates that the “dramatic increase” alluded to by Bauer (2011: 543) is not to be taken as a sign of a new structural innovation, but rather as a fortuitous exploitation of a well-settled word-formation pattern.  相似文献   

18.
Tamás Halm 《Morphology》2018,28(4):359-396
The non-possessive uses of possessive morphology in Uralic languages have been a topic of intense debate (Fraurud 2001; Nikolaeva 2003; Gerland 2014; Janda 2015; É. Kiss and Tánczos to appear). In this paper, I focus on a special use of the poss.3sg suffix in Hungarian constructions such as a hülyéje (the stupid-poss.3sg): lit. ‘its stupid’, meaning ‘that total idiot’. My main claim is that this suffix is an affective demonstrative suffix (Lakoff 1974; Liberman 2008; Potts and Schwarz 2010), and that it has developed as a result of grammaticalization from a full-fledged possessive construction of the form a világ hülyéje (the world stupid-poss.3sg): lit. ‘the world’s stupid’, meaning: ‘the biggest idiot in the world’. I will show that this gradual process can be reconstructed fairly accurately using historical and contemporary corpora. I also claim that this grammaticalization pathway is very natural as it is based on a set-element relationship which is often expressed by possessive constructions cross-linguistically. I also identify two parameters which facilitate this grammaticalization process: the availability of (silent) pro possessors and the lack of gender agreement on the possessive suffix. Since Uralic languages in general have these parameters, I will argue that this grammaticalization pathway should at least be considered as one of the possible sources of the demonstrative (and definiteness marking) uses of poss.3sg suffixes in Uralic languages. Finally, my results are also an important contribution to the debate on whether demonstratives can be derived from other functional elements through grammaticalization (Plank 1979; Traugott 1982; Himmelmann 1997).  相似文献   

19.
Most psycholinguistic models of lexical processing assume that the comprehension and production of inflected forms is mediated by morphemic constituents. Several more recent studies, however, have challenged this assumption by providing empirical evidence that information about individual inflected forms and their paradigmatic relations is available in long-term memory (Baayen et al. 1997; Milin et al. 2009a, 2009b). Here, we investigate how whole-word frequency, inflectional paradigm size and morphological family size affect production latencies and articulation durations when subjects are asked to read aloud isolated Estonian case-inflected nouns. In Experiment 1, we observed that words with a larger morphological family elicited shorter speech onset latencies, and that forms with higher whole-word frequency had shorter acoustic durations. Experiment 2, for which we increased statistical power by using 2,800 words, revealed that higher whole-word frequency, inflectional paradigm size, and morphological family size reduced both speech onset times and acoustic durations. These results extend our knowledge of morphological processing in three ways. First, whole-word frequency effects of inflected forms in morphologically rich languages are not restricted to a small number of very high-frequency forms, contrary to previous claims (Niemi et al. 1994; Hankamer 1989; Yang 2016). Second, we replicated the morphological family size effect in a new domain, the acoustic durations of inflected forms. Third, we showed that a novel paradigmatic measure, inflectional paradigm size, predicts word naming latencies and acoustic durations. These results fit well with Word-and-Paradigm morphology (Blevins 2016) and argue against strictly (de)compositional models of lexical processing.  相似文献   

20.
North American glyptodonts originated from South American ancestors during the Great American Biotic Interchange no later than early Blancan North American Land Mammal Age (NALMA). A substantial expansion in population samples from the late Blancan 111 Ranch fauna of southeastern Arizona, several late Blancan faunas in New Mexico, and the early Blancan–Irvingtonian faunas of Guanajuato, Mexico, permit, analysis of sexual dimorphism and ontogeny of Glyptotherium texanum Osborn, 1903. Growth of carapacial osteoderms was allometric, including changes of the external sculpturing. Overall anatomy of the carapace changed with growth, with development of distinctive pre-iliac and post-iliac regions in lateral profile of adults. Skulls of adults possess a unique boss on the anterior surface of the descending process of the zygomatic arch that is not present in juveniles. Sexual dimorphism involves differences in anatomy of lateral and posterior osteoderms. Glyptotherium arizonae Gidley, 1926, is a junior synonym of G. texanum. The temporal distribution of G. texanum extends from early Blancan NALMA to Irvingtonian NALMA, with geographical distribution from Central America and Mexico to southern United States.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号