Transcultural aspects of eating disorders: A critical literature review

A review of studies addressing anorexia nervosa and bulimia nervosa among Native Americans, African-Americans, Hispanics, Asians, Africans, and Middle Easterners yielded only 35 studies, of which 22 were qualitative case reports, three were clinical quantitative studies, and ten were non-clinical quantitative studies. The case studies reported symptoms similar to those of Caucasian patients, and eating disorders were reported in all SES classes. The clinical studies, all reported from Asian countries, described a number of cases for eating disorders quite different from one another. The non-clinical quantitative studies reported a number of cases consistent with the ranges previously reported for controlled samples of non-clinical Caucasian populations. We found few or no quantitative studies on eating disorders from Hispanic, Middle Eastern, African, or Asian countries other than Japan.     

Modeling neurodegenerative disorders in adult somatic cells: A critical review

Development of new therapeutic targets for neurodegenerative disorders has been hampered by a reliance on post mortem tissue that is representative of end-stage disease, or on animal models that fail to provide faithful analogs. However, rapid advances in cellular genetic reprogramming, in particular the induction of somatic cells into stem cells, or directly into neurons, has led to intense interest in modeling of human neurodegeneration in vitro. Here, we critically review current methods and recent progress in cellular models of Alzheimer’s disease, Parkinson’s disease and amyotrophic lateral sclerosis. Several challenges are identified, including technical variability, lack of degenerative phenotypes, neurodevelopmental age and establishing ground truths for models of sporadic disease. Recommendations for evaluating neurodegenerative cellular models are proposed along with suggestions for future research.     

工业生态学的内涵与发展

作为一门发展不到20a的综合性交叉学科,工业生态学目前需要界定其学术范畴和理论基础.首先评述了工业生态学的4个主要领域:(1)社会代谢是工业生态学起源最早也是发展最为成熟的领域.它提供了宏观层次上观察和测量经济发展与物质流动关系的方法和工具,但需要进一步细化物质流动图景和加强流动机制的解释;(2)工业共生是工业生态学最具特征的领域.它实质上是人们出于观察视角的转变而对工业体系的重新认识.逻辑严谨且规则统一的解释框架有助于工业共生理论的发展和实践;(3)基础设施与产业相互选择且协同演进,二者共同构成了城市的物质基础,而城市又是更大范围内区域经济系统的子集.这一组工业生态学的研究对象需要处理产业全球化与社会和生态要素本土化的矛盾;(4)工业发展的可持续性是工业生态学关注的核心目标,而多样性和复杂性给其研究带来了很大的挑战.这提醒我们要避免陷入简单化、还原论或机械论的陷阱,多开展实证研究.最后,从本体论、方法论和隐喻3个标准给出了工业生态学的初步界定,并指出4个重要的努力方向.     

Anandamide transport: a critical review

Anandamide (AEA) uptake has been described over the last decade to occur by facilitated diffusion, but a protein has yet to be isolated. In some cell types, it has recently been suggested that AEA, an uncharged hydrophobic molecule, passively diffuses through the plasma membrane in a process that is not protein-mediated. Since that observation, recent kinetics studies (using varying assay conditions) have both supported and denied the presence of an AEA transporter. In this review, we analyze the current literature exploring the mechanism of AEA uptake and endeavor to explain the reasons for the divergent views. One of the main variables among laboratories is the incubation time of the cells with AEA. Initial kinetics (at time points <1 min depending upon the cell type) isolate events that occur at the plasma membrane and are most useful to study saturability of uptake and effects of purported transport inhibitors upon uptake. Results with longer incubation times reflect events not only at the plasma membrane but also interactions at intracellular sites that may include enzyme(s), other proteins, or specialized lipid-binding domains. Furthermore, at long incubation times, antagonists to AEA receptors reduce AEA uptake. Another complicating factor in AEA transport studies is the nonspecific binding to plastic culture dishes. The magnitude of this effect may exceed AEA uptake into cells. Likewise, AEA may be released from plastic culture dishes (without cells) in such a manner as to mimic efflux from cells. AEA transport protocols using BSA, similar to the method used for fatty acid uptake studies, are gaining acceptance. This may improve AEA solution stability and minimize binding to plastic, although some groups report that BSA interferes with uptake. In response to criticisms that many transport inhibitors also inhibit the fatty acid amide hydrolase (FAAH), new compounds have recently been synthesized. Following their characterization in FAAH+/+ and FAAH-/- cells and transgenic mice, several inhibitors have been shown to have physiological activity in FAAH-/- mice. Their targets are now being characterized with the possibility that a protein transporter for AEA may be characterized.     

Puberty as a critical risk period for eating disorders: A review of human and animal studies

This article is part of a Special Issue “Puberty and Adolescence”.     

Psychiatrically hospitalized children: a critical review

The high cost of inpatient hospitalization and the rise in the number of private psychiatric beds for children and adolescents prompt several questions about who is using these services. To examine these issues, a review focusing on the use of psychiatric inpatient services by children was undertaken. The history of inpatient care of children is briefly outlined, recent public policies contributing to the rise in the number of psychiatric beds are considered, and findings from available studies are reviewed. We conclude that the data base is inadequate to draw many conclusions about who is using child psychiatric inpatient services. There appear, however, to be important differences in use of inpatient services according to age and perhaps by institutional type and geographic region. Suggestions for future research and some of the social policy implications are discussed as well.     

Bone morphogenetic proteins: a critical review

Bone Morphogenetic Proteins (BMPs) are potent growth factors belonging to the Transforming Growth Factor Beta superfamily. To date over 20 members have been identified in humans with varying functions during processes such as embryogenesis, skeletal formation, hematopoesis and neurogenesis. Though their functions have been identified, less is known regarding levels of regulation at the extracellular matrix, membrane surface, and receptor activation. Further, current models of activation lack the integration of these regulatory mechanisms. This review focuses on the different levels of regulation, ranging from the release of BMPs into the extracellular components to receptor activation for different BMPs. It also highlights areas in research that is lacking or contradictory.     

Speciation through competition: a critical review

We examined causes of speciation in asexual populations in both sympatry and parapatry, providing an alternative explanation for the speciation patterns reported by Dieckmann and Doebeli (1999) and Doebeli and Dieckmann (2003). Both in sympatry and parapatry, they find that speciation occurs relatively easily. We reveal that in the sympatric clonal model, the equilibrium distribution is continuous and the disruptive selection driving evolution of discrete clusters is only transient. Hence, if discrete phenotypes are to remain stable in the sympatric sexual model, there should be some source of nontransient disruptive selection that will drive evolution of assortment. We analyze sexually reproducing populations using the Bulmer's infinitesimal model and show that cost-free assortment alone leads to speciation and disruptive selection only arises when the optimal distribution cannot be matched--in this example, because the phenotypic range is limited. In addition, Doebeli and Dieckmann's analyses assumed a high genetic variance and a high mutation rate. Thus, these theoretical models do not support the conclusion that sympatric speciation is a likely outcome of competition for resources. In their parapatric model (Doebeli and Dieckmann 2003), clustering into distinct phenotypes is driven by edge effects, rather than by frequency-dependent competition.     

Back-calculation of fish length: a critical review

A review is made of the literature on the back-calculation of fish body length from marks on scales or other hard parts (otoliths, vertebrae, fin rays, etc.). Though the technique is widely used it does not appear to be well understood. Regression methods are commonly used, apparently in ignorance of the more realistic proportional methods. It is not generally recognized that there are two equally plausible back-calculation hypotheses which can lead to significantly different back-calculated lengths. The Fraser-Lee equation, the most commonly used back-calculated formula, follows neither of these hypotheses but is based on a misuse of linear regression. It is recommended that back-calculation be restricted to procedures following one of the proportional hypotheses; that the difference between lengths calculated using the two hypotheses is a useful measure of the minimum uncertainty in back-calculation lengths; and that more attention be paid to validating back-calculation hypotheses by comparing observed and back-calculated lengths for individual fish. The pattern of heteroscedasticity in body length–scale radius plots is noted as a useful diagnostic in evaluating back-calculation hypothesis.     

Sodium transport in plants: a critical review

Sodium (Na) toxicity is one of the most formidable challenges for crop production world-wide. Nevertheless, despite decades of intensive research, the pathways of Na(+) entry into the roots of plants under high salinity are still not definitively known. Here, we review critically the current paradigms in this field. In particular, we explore the evidence supporting the role of nonselective cation channels, potassium transporters, and transporters from the HKT family in primary sodium influx into plant roots, and their possible roles elsewhere. We furthermore discuss the evidence for the roles of transporters from the NHX and SOS families in intracellular Na(+) partitioning and removal from the cytosol of root cells. We also review the literature on the physiology of Na(+) fluxes and cytosolic Na(+) concentrations in roots and invite critical interpretation of seminal published data in these areas. The main focus of the review is Na(+) transport in glycophytes, but reference is made to literature on halophytes where it is essential to the analysis.     

Trichloroethylene and dichloroethylene: a critical review of teratogenicity

Trichloroethylene (TCE) and dichloroethylene (DCE) are high-volume industrial chemicals frequently found as contaminants in public drinking water supplies. The developmental toxicity of both chemicals has been evaluated in laboratory and epidemiologic studies. It has been suggested that TCE and DCE are specific cardiac teratogens and that drinking water contaminated with them increases the risk of congenital heart defects in exposed human populations. In contrast, other laboratory and epidemiologic studies do not find an increase in developmental effects, either in general or specifically affecting the heart. This laboratory and epidemiologic base was reviewed to evaluate the strengths and weaknesses of the conflicting published reports. We conclude that the weight of experimental and epidemiologic evidence does not support the hypothesis that TCE or DCE is a selective developmental toxicant in general or a cardiac teratogen specifically.     

Potential biotechnological application of microalgae: a critical review

Microalgae are diverse microorganisms inhabiting a wide range of habitats with only a small fraction being cultivated for human use. Recently, interest in microalgal research has increased in the quest for alternative renewable fuels due to possible depletion of fossil fuels in the near future. However, costly downstream processing has hampered the commercialization of biofuels derived from microalgae. Several value added products of industrial, pharmaceutical and agricultural relevance could be simultaneously derived from microalgae during bioenergy production. Despite these value-added products having the potential to offset the high cost of downstream processing of renewable fuels, their production has not been explored in-depth. This review presents a critical overview of the current state of biotechnological applications of microalgae for human benefit and highlights possible areas for further research and development.