An idealized study of coupled atmosphere-ocean 4D-Var in the presence of model error

Atmosphere only and ocean only variational data assimilation (DA) schemes are able to use window lengths that are optimal for the error growth rate, non-linearity and observation density of the respective systems. Typical window lengths are 6-12 hours for the atmosphere and 2-10 days for the ocean. However, in the implementation of coupled DA schemes it has been necessary to match the window length of the ocean to that of the atmosphere, which may potentially sacrifice the accuracy of the ocean analysis in order to provide a more balanced coupled state. This paper investigates how extending the window length in the presence of model error affects both the analysis of the coupled state and the initialized forecast when using coupled DA with differing degrees of coupling. Results are illustrated using an idealized single column model of the coupled atmosphere-ocean system. It is found that the analysis error from an uncoupled DA scheme can be smaller than that from a coupled analysis at the initial time, due to faster error growth in the coupled system. However, this does not necessarily lead to a more accurate forecast due to imbalances in the coupled state. Instead coupled DA is more able to update the initial state to reduce the impact of the model error on the accuracy of the forecast. The effect of model error is potentially most detrimental in the weakly coupled formulation due to the inconsistency between the coupled model used in the outer loop and uncoupled models used in the inner loop.

Expression of AmphiCoe, an amphioxus COE/EBF gene, in the developing central nervous system and epidermal sensory neurons

The COE/EBF gene family marks a subset of prospective neurons in the vertebrate central and peripheral. nervous system; including neurons deriving from some ectodermal placodes. Since placodes are often considered unique to vertebrates, we have characterised an amphioxus COE/EBF gene with the aim of using it as a marker to examine the timing and location of peripheral neuron differentiation. A single COE/EBF family member, AmphiCoe, was isolated from the amphioxus Branchiostoma floridae: AmphiCoe lies basal to the vertebrate COE/EBF genes in molecular phylogenetic analysis, suggesting that the duplications that formed the vertebrate COE/EBF family were specific to the vertebrate lineage. AmphiCoe is expressed in the central nervous system and in a small number of scattered ectodermal cells on the flanks of neurulae stage embryos. These cells become at least largely recessed beneath the ectoderm. Scanning electron microscopy was used to examine embryos in which the ectoderm had been partially peeled away. This revealed that these cells have neuronal morphology, and we infer that they are the precursors of epidermal primary sensory neurons. These characters lead us to suggest that differentiation of some ectodermal cells into sensory neurons with a tendency to sink beneath the embryonic surface represents a primitive feature that has become incorporated into placodes during vertebrate evolution. (C) 2004 Wiley-Liss, Inc.

Pax gene expression in the developing central nervous system of Ciona intestinalis

We compare the expression patterns in Ciona intestinalis of three members of the Pax gene family, CiPax3/7, CiPax6 and Cipax2/5/8. All three genes are expressed in restricted patterns in the developing central nervous system. At the tailbud stage, CiPax3/7 is present in three patches in the brain and along the posterior neural tube, CiPax6 throughout the anterior brain and along the posterior neural tube and CiPax2/5/8 in a restricted region of the posterior brain. Double in situ hybridisations were used to identify areas of overlap between the expression of different genes. This showed that CiPax3/7 overlaps with the boundaries of CiPax6 expression in the anterior brain, and with CiPax2/5/8 in the posterior brain. The overlap between CiPax3/7 and CiPax2/5/8 is unlike that described in the ascidian Halocynthia rorezti. (C) 2003 Elsevier B.V. All rights reserved.

Family interventions in psychosis: a scale to measure therapist adherence

The efficacy of family interventions in psychosis is well documented. UK and USA schizophrenia treatment guidelines advocate the practice of family interventions within routine clinical services. However, less attention has been paid to the study of treatment fidelity and the tools used in its assessment. This study reports the inter-rater reliability of a new scale: Family Intervention in Psychosis-Adherence Scale (FIPAS). This measure is designed to assess therapist adherence to the Kuipers et al. (2002) family intervention in psychosis treatment manual. Reliability ratings were based on a sample of thirteen audiotapes drawn from a randomized controlled trial of family intervention. The results indicated that the majority of items of the FIPAS had acceptable levels of inter-rater reliability. The findings are discussed in terms of their implications for the training and monitoring of the effectiveness of practitioners for family interventions in psychosis.

Fractal-to-Euclidean crossover of the isotropy restoration feature in a family of fractal resistor networks

Fractal with microscopic anisotropy shows a unique type of macroscopic isotropy restoration phenomenon that is absent in Euclidean space [M. T. Barlow et al., Phys. Rev. Lett. 75, 3042]. In this paper the isotropy restoration feature is considered for a family of two-dimensional Sierpinski gasket type fractal resistor networks. A parameter xi is introduced to describe this phenomenon. Our numerical results show that xi satisfies the scaling law xi similar to l(-alpha), where l is the system size and alpha is an exponent independent of the degree of microscopic anisotropy, characterizing the isotropy restoration feature of the fractal systems. By changing the underlying fractal structure towards the Euclidean triangular lattice through increasing the side length b of the gasket generators, the fractal-to-Euclidean crossover behavior of the isotropy restoration feature is discussed.

Family language policy in the Chinese community in Singapore: a question of balance?

This paper focuses on the language shift phenomenon in Singapore as a consequence of the top-town policies. By looking at bilingual family language policies it examines the characteristics of Singapore’s multilingual nature and cultural diversity. Specifically, it looks at what languages are practiced and how family language policies are enacted in Singaporean English-Chinese bilingual families, and to what extend macro language policies – i.e. national and educational language policies influence and interact with family language policies. Involving 545 families and including parents and grandparents as participants, the study traces the trajectory of the policy history. Data sources include 2 parts: 1) a prescribed linguistic practices survey; and 2) participant observation of actual negotiation of FLP in face-to-face social interaction in bilingual English-Chinese families. The data provides valuable information on how family language policy is enacted and language practices are negotiated, and what linguistic practices have been changed and abandoned against the background of the Speaking Mandarin Campaign and the current bilingual policy implemented in the 1970s. Importantly, the detailed face-to-face interactions and linguistics practices are able to enhance our understanding of the subtleties and processes of language (dis)continuity in relation to policy interventions. The study also discusses the reality of language management measures in contrast to the government’s ‘separate bilingualism’ (Creese & Blackledge, 2011) expectations with regard to ‘striking a balance’ between Asian and Western culture (Curdt-Christiansen & Silver 2013; Shepherd, 2005) and between English and mother tongue languages (Curdt-Christiansen, 2014). Demonstrating how parents and children negotiate their family language policy through translanguaging or heteroglossia practices (Canagarajah, 2013; Garcia & Li Wei, 2014), this paper argues that ‘striking a balance’ as a political ideology places emphasis on discrete and separate notions of cultural and linguistic categorization and thus downplays the significant influences from historical, political and sociolinguistic contexts in which people find themselves. This simplistic view of culture and linguistic code will inevitably constrain individuals’ language expression as it regards code switching and translanguaging as delimited and incompetent language behaviour.