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BACKGROUND: The ferroxidase zyklopen (Zp) has been implicated in the placental transfer of iron to the fetus. However, the evidence for this is largely circumstantial. OBJECTIVES: This study aimed to determine whether Zp is essential for placental iron transfer. METHODS: A model was established using 8- to 12-wk-old pregnant C57BL/6 mice on standard rodent chow in which Zp was knocked out in the fetus and fetal components of the placenta. Zp was also disrupted in the entire placenta using global Zp knockout mice. Inductively coupled plasma MS was used to measure total fetal iron, an indicator of the amount of iron transferred by the placenta to the fetus, at embryonic day 18.5 of gestation. Iron transporter expression in the placenta was measured by Western blotting, and the expression of Hamp1, the gene encoding the iron regulatory hormone hepcidin, was determined in fetal liver by real-time PCR. RESULTS: There was no change in the amount of iron transferred to the fetus when Zp was disrupted in either the fetal component of the placenta or the entire placenta. No compensatory changes in the expression of the iron transport proteins transferrin receptor 1 or ferroportin were observed, nor was there any change in fetal liver Hamp1 mRNA. Hephl1, the gene encoding Zp, was expressed mainly in the maternal decidua of the placenta and not in the nutrient-transporting syncytiotrophoblast. Disruption of Zp in the whole placenta resulted in a 26% increase in placental size (P

This paper investigates the relative importance of social and cultural capitals in (re)shaping a tourism resource governance approach for supporting sustainable livelihood outcomes. We apply a ‘Cap...

A broader view of sustainable tourism development is becoming increasingly apparent, in which the discourse of sustainability has been extended to include notions of tourism/community capitals, sus...

Objective Sulfation is an essential physiological process that regulates the function of a wide array of molecules involved in brain development. We have previously shown expression levels for the sulfate transporter Slc13a4 to be elevated during postnatal development, and that sulfate accumulation in the brains of Slc13a4+/− mice is reduced, suggesting a role for this transporter during this critical window of brain development. In order to understand the pathways regulated by cellular sulfation within the brain, we performed a bulk RNA-sequencing analysis of the forebrain of postnatal day 20 (P20) Slc13a4 heterozygous mice and wild-type litter mate controls. Data description We performed an RNA transcriptomic based sequencing screen on the whole forebrain from Slc13a4+/− and Slc13a4+/+mice at P20. Differential expression analysis revealed 90 differentially regulated genes in the forebrain of Slc13a4+/− mice (a p-value of 0.1 was considered as significant). Of these, 55 were upregulated, and 35 were downregulated in the forebrain of heterozygous mice. Moreover, when we stratified further with a ± 1.2 fold-change, we observed 38 upregulated, and 16 downregulated genes in the forebrain of heterozygous mice. This resource provides a useful tool to interrogate which pathways may require elevated sulfate levels to drive normal postnatal development of the brain.

Sulfate is a key anion required for a range of physiological functions within the brain. These include sulfonation of extracellular proteoglycans to facilitate local growth factor binding and to regulate the shape of morphogen gradients during development. We have previously shown that mice lacking one allele of the sulfate transporter Slc13a4 exhibit reduced sulfate transport into the brain, deficits in social behaviour, reduced performance in learning and memory tasks, and abnormal neurogenesis within the ventricular/subventricular zone lining the lateral ventricles. However, whether these mice have deficits in hippocampal neurogenesis was not addressed. Here, we demonstrate that adult Slc13a4+/− mice have increased neurogenesis within the subgranular zone (SGZ) of the hippocampal dentate gyrus, with elevated numbers of neural progenitor cells and intermediate progenitors. In contrast, by 12 months of age there were reduced numbers of neural stem cells in the SGZ of heterozygous mice. Importantly, we did not observe any changes in proliferation when we isolated and cultured progenitors in vitro in neurosphere assays, suggestive of a cell-extrinsic requirement for sulfate in regulating hippocampal neurogenesis. Collectively, these data demonstrate a requirement for sulfate transport during postnatal brain development to ensure normal adult hippocampal neurogenesis., Summary Statement: Heterozygosity for the brain sulfate transporter Slc13a4 during postnatal development results in life-long abnormal hippocampal neurogenesis.

The major milestones in mouse placental development are well described, but our understanding is limited to how the placenta can adapt to damage or changes in the environment. By using stereology and expression of cell cycle markers, we found that the placenta grows under normal conditions not just by hyperplasia of trophoblast cells but also through extensive polyploidy and cell hypertrophy. In response to feeding a low protein diet to mothers prior to and during pregnancy, to mimic chronic malnutrition, we found that this normal program was altered and that it was influenced by the sex of the conceptus. Male fetuses showed intrauterine growth restriction (IUGR) by embryonic day (E) 18.5, just before term, whereas female fetuses showed IUGR as early as E16.5. This difference was correlated with differences in the size of the labyrinth layer of the placenta, the site of nutrient and gas exchange. Functional changes were implied based on up-regulation of nutrient transporter genes. The junctional zone was also affected, with a reduction in both glycogen trophoblast and spongiotrophoblast cells. These changes were associated with increased expression of Phlda2 and reduced expression of Egfr. Polyploidy, which results from endoreduplication, is a normal feature of trophoblast giant cells (TGC) but also spongiotrophoblast cells. Ploidy was increased in sinusoidal-TGCs and spongiotrophoblast cells, but not parietal-TGCs, in low protein placentas. These results indicate that the placenta undergoes a range of changes in development and function in response to poor maternal diet, many of which we interpret are aimed at mitigating the impacts on fetal and maternal health.

Triheptanoin, the triglyceride of heptanoate, is anaplerotic (refills deficient tricarboxylic acid cycle intermediates) via the propionyl-CoA carboxylase (PCC) pathway. It has been shown to be neuroprotective and anticonvulsant in several models of neurological disorders. Here, we investigated the effects of triheptanoin against changes of hippocampal mitochondrial functions, oxidative stress and cell death induced by pilocarpine-induced status epilepticus (SE) in mice. Ten days of triheptanoin pre-treatment did not protect against SE, but it preserved hippocampal mitochondrial functions including state 2, state 3 ADP, state 3 uncoupled respiration, respiration linked to ATP synthesis along with the activities of pyruvate dehydrogenase complex and oxoglutarate dehydrogenase complex 24 h post-SE. Triheptanoin prevented the SE-induced reductions of hippocampal mitochondrial superoxide dismutase activity and plasma antioxidant status as well as lipid peroxidation. It also reduced neuronal degeneration in hippocampal CA1 and CA3 regions three days after SE. In addition, heptanoate significantly reduced hydrogen peroxide-induced cell death in cultured neurons. In situ hybridization localized the enzymes of the PCC pathway, specifically Pccα, Pccβ and methylmalonyl-CoA mutase to adult mouse hippocampal pyramidal neurons and dentate granule cells, indicating that anaplerosis may occur in neurons. In conclusion, triheptanoin appears to have anaplerotic and antioxidant effects which contribute to its neuroprotective properties. This article is protected by copyright. All rights reserved.

Disruptions to either sulfate supply or sulfation enzymes can affect brain development and have long-lasting effects on brain function, yet our understanding of the molecular mechanisms governing this are incomplete. Perineuronal nets (PNNs) are highly sulfated, specialized extracellular matrix structures that regulate the maturation of synaptic connections and neuronal plasticity. We have previously shown that mice heterozygous for the brain sulfate transporter Slc13a4 have abnormal social interactions, memory, exploratory behaviors, stress and anxiety of postnatal origin, pointing to potential deficits in PNN biology, and implicate SLC13A4 as a critical factor required for regulating normal synaptic connectivity and function. Here, we sought to investigate aberrant PNN formation as a potential mechanism contributing to the functional deficits displayed by Slc13a4+/- mice. Following social interactions, we reveal reduced neuronal activation in the somatosensory cortex of Slc13a4+/- mice, and altered inhibitory and excitatory postsynaptic currents. In line with this, we found a reduction in parvalbumin-expressing neurons decorated with PNNs, as well as reduced expression of markers for PNN maturation. Finally, we reveal that postnatal administration of N-acetylcysteine prevented PNN abnormalities from manifesting in Slc13a4+/- adult animals. Collectively, these data highlight a central role for postnatal SLC13A4 in normal PNN formation, circuit function and subsequent animal behavior.

Public participation is considered a cornerstone of sustainable tourism planning. Although this process is well established and tested in western democracies, there is an emerging trend of developing it within the liberalizing Chinese tourism economy. Using a qualitative research strategy, this paper applies the theoretical construction of community participation in tourism planning to the analysis of the planning process of a tourism destination in Jiao Chang Wei, Shenzhen, China. The paper finds that: 1) public participation has played a significant role in the formulation and implementation of the tourism destination plan in the case study area. 2) Structuralized inter-network collaboration led-by government organized non-governmental organizations has the potential to become dominant paradigm of public participation in tourism planning in China in the future. The paper concludes with the contributions of this research to wider theory.

Background A male fetus is suggested to be more susceptible to in utero and birth complications. This may be due in part to altered morphology or function of the XY placenta. We hypothesised that sexual dimorphism begins at the blastocyst stage with sex differences in the progenitor trophectoderm (TE) and its derived trophoblast lineages, as these cells populate the majority of cell types within the placenta. We investigated sex-specific differences in cell allocation in the pre-implantation embryo and further characterised growth and gene expression of the placental compartments from the early stages of the definitive placenta through to late gestation. Methods Naturally mated Sprague Dawley dams were used to collect blastocysts at embryonic day (E) 5 to characterise cell allocation; total, TE, and inner cell mass (ICM), and differentiation to downstream trophoblast cell types. Placental tissues were collected at E13, E15, and E20 to characterise volumes of placental compartments, and sex-specific gene expression profiles. Results Pre-implantation embryos showed no sex differences in cell allocation (total, TE and ICM) or early trophoblast differentiation, assessed by outgrowth area, number and ploidy of trophoblasts and P-TGCs, and expression of markers of trophoblast stem cell state or differentiation. Whilst no changes in placental structures were found in the immature E13 placenta, the definitive E15 placenta from female fetuses had reduced labyrinthine volume, fetal and maternal blood space volume, as well as fetal blood space surface area, when compared to placentas from males. No differences between the sexes in labyrinth trophoblast volume or interhaemal membrane thickness were found. By E20 these sex-specific placental differences were no longer present, but female fetuses weighed less than their male counterparts. Coupled with expression profiles from E13 and E15 placental samples may suggest a developmental delay in placental differentiation. Conclusions Although there were no overt differences in blastocyst cell number or early placental development, reduced growth of the female labyrinth in mid gestation is likely to contribute to lower fetal weight in females at E20. These data suggest sex differences in fetal growth trajectories are due at least in part, to differences in placenta growth. Electronic supplementary material The online version of this article (doi:10.1186/s13293-017-0138-6) contains supplementary material, which is available to authorized users.

The development of pathologies during pregnancy, including pre-eclampsia, hypertension and fetal growth restriction (FGR), often originates from poor functioning of the placenta. In vivo models of maternal stressors, such as nutrient deficiency, and placental insufficiency often focus on inadequate growth of the fetus and placenta in late gestation. These studies rarely investigate the origins of poor placental formation in early gestation, including those affecting the pre-implantation embryo and/or the uterine environment. The current study characterises the impact on blastocyst, uterine and placental outcomes in a rat model of periconceptional alcohol exposure, in which 12.5% ethanol is administered in a liquid diet from 4 days before until 4 days after conception. We show female-specific effects on trophoblast differentiation, embryo-uterine communication, and formation of the placental vasculature, resulting in markedly reduced placental volume at embryonic day 15. Both sexes exhibited reduced trophectoderm pluripotency and global hypermethylation, suggestive of inappropriate epigenetic reprogramming. Furthermore, evidence of reduced placental nutrient exchange and reduced pre-implantation maternal plasma choline levels offers significant mechanistic insight into the origins of FGR in this model.

Who are key stakeholders in tourism and who among them are addressing issues of overtourism? The answers depend on the role of the state and the general approaches to governance in the particular destination. In the member countries of the Organisa­tion for Economic Co-operation and Development (OECD), for example, development builds on three dimensions, namely effective and accountable governance, growth and social cohesion (including well-being and equity). Other countries, such as China, are transforming from communist to market-oriented economies (albeit state­controlled), and this change is bringing with it key challenges such as economic inequality and environmental degradation. Such challenges have led to a call for new arrangements and the participation in decision making of all stakeholders, including local communities, to achieve positive outcomes from development, including from tourism development (Lin and Simmons, 2017; Su et al., 2014). Tourism is rife with market failures (Simmons, 2017) and, as such, has experienced boom and bust cycles commonly seen in other resource-based sectors, such as mining (for a comparison of mining and tourism see Moyle, Moyle and Becken, 2018; for exam­ples of booms and busts in the history of a tourism destination see McAloon et al., 1998). Put simply, market failure is when the outcome of market forces is unsatisfac­tory from the perspective of society. One type of market failure is when the market fails to price, or include all costs associated with production or consumption, resulting in "externalities" (e.g. pollution). Addressing such externalities requires suitable gover­nance arrangements, such as the intervention by the government in the form of legisla­tion or taxes (UNWTO and Griffith University, 2017)

Significance Zn2+, Mg2+, and Ca2+ are the most abundant divalent metals in mammals. Different categories of cation-selective channels and transporters are thought to control the levels of individual metals in a cell-specific manner. However, the mechanisms responsible for the organismal balance of these minerals are poorly understood. Using genetic mouse models together with biophysical and biochemical analysis, we show that the channel-kinase TRPM7 is a master regulator of the organismal balance of divalent cations. TRPM7 activity is primarily required in the intestine, while TRPM7 function in the kidney—commonly thought to be essential—is expendable. Hence, against current thinking, organismal balance of multiple divalent cations predominantly relies on a common gatekeeper, TRPM7, rather than on individual specialized channels/transporters., Zn2+, Mg2+, and Ca2+ are essential minerals required for a plethora of metabolic processes and signaling pathways. Different categories of cation-selective channels and transporters are therefore required to tightly control the cellular levels of individual metals in a cell-specific manner. However, the mechanisms responsible for the organismal balance of these essential minerals are poorly understood. Herein, we identify a central and indispensable role of the channel-kinase TRPM7 for organismal mineral homeostasis. The function of TRPM7 was assessed by single-channel analysis of TRPM7, phenotyping of TRPM7-deficient cells in conjunction with metabolic profiling of mice carrying kidney- and intestine-restricted null mutations in Trpm7 and animals with a global “kinase-dead” point mutation in the gene. The TRPM7 channel reconstituted in lipid bilayers displayed a similar permeability to Zn2+ and Mg2+. Consistently, we found that endogenous TRPM7 regulates the total content of Zn2+ and Mg2+ in cultured cells. Unexpectedly, genetic inactivation of intestinal rather than kidney TRPM7 caused profound deficiencies specifically of Zn2+, Mg2+, and Ca2+ at the organismal level, a scenario incompatible with early postnatal growth and survival. In contrast, global ablation of TRPM7 kinase activity did not affect mineral homeostasis, reinforcing the importance of the channel activity of TRPM7. Finally, dietary Zn2+ and Mg2+ fortifications significantly extended the survival of offspring lacking intestinal TRPM7. Hence, the organismal balance of divalent cations critically relies on one common gatekeeper, the intestinal TRPM7 channel.

Background Sulfate availability is crucial for the sulfonation of brain extracellular matrix constituents, membrane phospholipids, neurosteroids, and neurotransmitters. Observations from humans and mouse models suggest dysregulated sulfate levels may be associated with neurodevelopmental disorders, such as autism. However, the cellular mechanisms governing sulfate homeostasis within the developing or adult brain are not fully understood. Methods We utilized a mouse model with a conditional allele for the sulfate transporter Slc13a4, and a battery of behavioral tests, to assess the effects of disrupted sulfate transport on maternal behaviors, social interactions, memory, olfaction, exploratory behavior, anxiety, stress, and metabolism. Immunohistochemistry examined neurogenesis within the stem cells niches. Findings The sulfate transporter Slc13a4 plays a critical role in postnatal brain development. Slc13a4 haploinsufficiency results in significant behavioral phenotypes in adult mice, notably impairments in social interaction and long-term memory, as well as increased neurogenesis in the subventricular stem cell niche. Conditional gene deletion shows these phenotypes have a developmental origin, and that full biallelic expression of Slc13a4 is required only in postnatal development. Furthermore, administration of N-acetylcysteine (NAC) within postnatal window P14-P30 prevents the onset of phenotypes in adult Slc13a4+/− mice. Interpretation Slc13a4 haploinsufficient mice highlight a requirement for adequate sulfate supply in postnatal development for the maturation of important social interaction and memory pathways. With evidence suggesting dysregulated sulfate biology may be a feature of some neurodevelopmental disorders, the utility of sulfate levels as a biomarker of disease and NAC administration as an early preventative measure should be further explored.

Workshops are an important part of the IFPA annual meeting as they allow for discussion of specialized topics. At IFPA meeting 2015 there were twelve themed workshops, three of which are summarized in this report. These workshops covered areas of placental regulation and nutrient handling: 1) placental epigenetics; 2) placental mitochondrial function; 3) placental transport systems.

This paper interrogates the changing role of local government in tourism development. It does so through the examination of the Hurunui District, a rural district in New Zealand which has experienced significant transformation in the tourism sector and a concomitant increase in public sector input over the past 25 years. By situating this interrogation within an evolving neoliberal public policy context, this paper explores the tensions at play between tourism stakeholders and decision-makers, and it critiques the way in which local government involvement in the sector is manifested as regulation, promotion, and ownership of key tourism resources in the District. The significance of this paper is that it extends our understanding of the role of the state in tourism and of the influence of public policy on tourism development, potentially including sustainable tourism development. Specifically, it draws our attention to the rationality, roles and activities of public sector engagement in the touris...

Address correspondence to Dr. Jude Wilson, Lincoln University, PO Box 85084, Lincoln 7647, Christchurch, New Zealand. Tel: +64 3 423 0502; E-mail: Jude.Wilson@lincoln.ac.nz with being a sustainable cruise destination (Lester & Weeden, 2004). This article reports on a study of community attitudes to cruise tourism in the small harbor town of Akaroa, New Zealand. It does so in the context of a period of unprecedented change and disruption to the region’s tourism sector as a consequence of the 2010/2011 Canterbury earthquakes. An important dimension of cruise tourism in Akaroa has been the arrival of large numbers of cruise visitors over a relatively short period of time; this growth trajectory contrasts markedly with the more incremental tourism growth patterns of land-based visitors experienced in Akaroa to date. Historically a busy MAKING WAVES: EXAMINING THE INTERFACE BETWEEN

The contribution of environmental factors to pancreatic islet damage in type 1 diabetes remains poorly understood. In this study, we crossed mice susceptible to type 1 diabetes, where parental male (CD8+ T cells specific for IGRP206-214; NOD8.3) and female (NOD/ShiLt) mice were randomized to a diet either low or high in AGE content and maintained on this diet throughout pregnancy and lactation. After weaning, NOD8.3+ female offspring were identified and maintained on the same parental feeding regimen for until day 28 of life. A low AGE diet, from conception to early postnatal life, decreased circulating AGE concentrations in the female offspring when compared to a high AGE diet. Insulin, proinsulin and glucagon secretion were greater in islets isolated from offspring in the low AGE diet group, which was akin to age matched non-diabetic C57BL/6 mice. Pancreatic islet expression of Ins2 gene was also higher in offspring from the low AGE diet group. Islet expression of glucagon, AGEs and the AGE receptor RAGE, were each reduced in low AGE fed offspring. Islet immune cell infiltration was also decreased in offspring exposed to a low AGE diet. Within pancreatic lymph nodes and spleen, the proportions of CD4+ and CD8+ T cells did not differ between groups. There were no significant changes in body weight, fasting glucose or glycemic hormones. This study demonstrates that reducing exposure to dietary AGEs throughout gestation, lactation and early postnatal life may benefit pancreatic islet secretion and immune infiltration in the type 1 diabetic susceptible mouse strain, NOD8.3.

The complement system, typically associated with innate immunity, is emerging as a key controller of nonimmune systems including in development, with recent studies linking complement mutations with neurodevelopmental disease. A key effector of the complement response is the activation fragment C5a, which, through its receptor C5aR1, is a potent driver of inflammation. Surprisingly, C5aR1 is also expressed during early mammalian embryogenesis; however, no clearly defined function is ascribed to C5aR1 in development. Here we demonstrate polarized expression of C5aR1 on the apical surface of mouse embryonic neural progenitor cellsin vivoand on human embryonic stem cell-derived neural progenitors. We also show that signaling of endogenous C5a during mouse embryogenesis drives proliferation of neural progenitor cells within the ventricular zone and is required for normal brain histogenesis. C5aR1 signaling in neural progenitors was dependent on atypical protein kinase C ζ, a mediator of stem cell polarity, with C5aR1 inhibition reducing proliferation and symmetric division of apical neural progenitors in human and mouse models. C5aR1 signaling was shown to promote the maintenance of cell polarity, with exogenous C5a increasing the retention of polarized rosette architecture in human neural progenitors after physical or chemical disruption. Transient inhibition of C5aR1 during neurogenesis in developing mice led to behavioral abnormalities in both sexes and MRI-detected brain microstructural alterations, in studied males, demonstrating a requirement of C5aR1 signaling for appropriate brain development. This study thus identifies a functional role for C5a–C5aR1 signaling in mammalian neurogenesis and provides mechanistic insight into recently identified complement gene mutations and brain disorders.SIGNIFICANCE STATEMENTThe complement system, traditionally known as a controller of innate immunity, now stands as a multifaceted signaling family with a broad range of physiological actions. These include roles in the brain, where complement activation is associated with diseases, including epilepsy and schizophrenia. This study has explored complement regulation of neurogenesis, identifying a novel relationship between the complement activation peptide C5a and the neural progenitor proliferation underpinning formation of the mammalian brain. C5a was identified as a regulator of cell polarity, with inhibition of C5a receptors during embryogenesis leading to abnormal brain development and behavioral deficits. This work demonstrates mechanisms through which dysregulation of complement causes developmental disease and highlights the potential risk of complement inhibition for therapeutic purposes in pregnancy.

The solute linked carrier 13A4 gene (SLC13A4) is abundantly expressed in the human and mouse placenta where it is proposed to transport nutrient sulfate to the fetus. In mice, targeted disruption of placental Slc13a4 leads to severe and lethal fetal phenotypes, however the involvement of SLC13A4 in human development is unknown. A search of the NCBI and Ensembl gene databases identified two alternatively spliced SLC13A4 mRNA transcripts and 98 SLC13A4 gene variants, including 85 missense, 4 splice site, 5 frameshift and 2 nonsense variants, as well as 2 in-frame deletions. We examined the relative abundance of the two SLC13A4 mRNA transcripts and then compared the sulfate transport function and plasma membrane expression of both isoforms as well as 6 sequence variants that predict disrupted SLC13A4 protein structure and function. SLC13A4 mRNA variant 1 has three additional nucleotides CAG compared to SLC13A4 mRNA variant 2 as a result of alternative splicing at the 5'-end of exon 6. Using qRT-PCR, we show a 4-fold higher abundance of SLC13A4 mRNA variant 1 compared to variant 2 in term human placentas and cultured BeWo and JEG-3 cell lines. The corresponding SLC13A4 protein isoforms 1 and 2 were found to have similar sulfate uptake activity and apical membrane expression in cultured MDCK cells. In addition, sulfate uptake into MDCK cells was similar between SLC13A4 isoform 1 and four missense variants N300S, F310C, E360Q and I570V, whereas V513M and frameshift variant L72Sfs led to partial (≈75% decrease) and complete loss-of-function, respectively. Localisation of these variants in MDCK cells showed N300S, E360Q, V513M and I570V expression on the apical plasma membrane, L72Sfs intracellularly and F310C on both apical and basolateral membranes. Our finding of partial and complete loss-of-function variants warrants further studies of the potential involvement of SLC13A4 in fetal pathophysiology.

Background and Purpose Subtypes of the hyperpolarization-activated cyclic nucleotide-gated (HCN) family of cation channels are widely expressed on nerves and smooth muscle cells in many organ systems, where they serve to regulate membrane excitability. Here we have assessed whether HCN channel inhibitors alter the function of airway smooth muscle or the neurons that regulate airway smooth muscle tone. Experimental Approach The effects of the HCN channel inhibitors ZD7288, zatebradine and Cs+ were assessed on agonist and nerve stimulation-evoked changes in guinea pig airway smooth muscle tone using tracheal strips in vitro, an innervated tracheal tube preparation ex vivo or in anaesthetized mechanically ventilated guinea pigs in vivo. HCN channel expression in airway nerves was assessed using immunohistochemistry, PCR and in situ hybridization. Key Results HCN channel inhibition did not alter airway smooth muscle reactivity in vitro to exogenously administered smooth muscle spasmogens, but significantly potentiated smooth muscle contraction evoked by the sensory nerve stimulant capsaicin and electrical field stimulation of parasympathetic cholinergic postganglionic neurons. Sensory nerve hyperresponsiveness was also evident in in vivo following HCN channel blockade. Cs+, but not ZD7288, potentiated preganglionic nerve-dependent airway contractions and over time induced autorhythmic preganglionic nerve activity, which was not mimicked by inhibitors of potassium channels. HCN channel expression was most evident in vagal sensory ganglia and airway nerve fibres. Conclusions and Implications HCN channel inhibitors had a previously unrecognized effect on the neural regulation of airway smooth muscle tone, which may have implications for some patients receiving HCN channel inhibitors for therapeutic purposes.

This article is part of research exploring various ways to visualize the complexity of sentient movement in space and time. In this case, visualization focuses on the movement of tourists on the West Coast of the South Island of New Zealand, with some commentary on national tourist activity. Working at the atomistic level of the individual we adopt space, time, and activity (s,t,a) as the three main dimensions of sentient movement, but we emphasize activity as a privileged dimension where visualization is involved. The rationale for this is that when interpreting movements of individuals or crowds, most itineraries either reflect resources in the environment that encourage travel or avoid risk or cause delay, resources ranging from food and water to incoming sunshine or rain. Activity and process is at the heart of most rich movement data-sets, and we suggest that using multiple-view visualization to decode (s,t,a) and environmental patterns opens further avenues for interpreting and communicating dynamic...

Sulfate is an important nutrient for fetal growth and development. The fetus has no mechanism for producing its own sulfate and is therefore totally reliant on sulfate from the maternal circulation via placental sulfate transport. To build a model of directional sulfate transport in the placenta, we investigated the relative abundance of the 10 known sulfate transporter mRNAs in human placenta from uncomplicated term pregnancies. SLC13A4 and SLC26A2 were the most abundant sulfate transporter mRNAs, which localized to syncytiotrophoblast and cytotrophoblast cells, respectively. These findings indicate important physiological roles for SLC13A4 and SLC26A2 in human placental sulfate transport.

Nutrient sulfate has numerous roles in mammalian physiology and is essential for healthy fetal growth and development. The fetus has limited capacity to generate sulfate and relies on sulfate supplied from the maternal circulation via placental sulfate transporters. The placenta also has a high sulfate requirement for numerous molecular and cellular functions, including sulfate conjugation (sulfonation) to estrogen and thyroid hormone which leads to their inactivation. Accordingly, the ratio of sulfonated (inactive) to unconjugated (active) hormones modulates endocrine function in fetal, placental and maternal tissues. During pregnancy, there is a marked increase in the expression of genes involved in transport and generation of sulfate in the mouse placenta, in line with increasing fetal and placental demands for sulfate. The maternal circulation also provides a vital reservoir of sulfate for the placenta and fetus, with maternal circulating sulfate levels increasing by 2-fold from mid-gestation. However, despite evidence from animal studies showing the requirement of maternal sulfate supply for placental and fetal physiology, there are no routine clinical measurements of sulfate or consideration of dietary sulfate intake in pregnant women. This is also relevant to certain xenobiotics or pharmacological drugs which when taken by the mother use significant quantities of circulating sulfate for detoxification and clearance, and thereby have the potential to decrease sulfonation capacity in the placenta and fetus. This article will review the physiological adaptations of the placenta for maintaining sulfate homeostasis in the fetus and placenta, with a focus on pathophysiological outcomes in animal models of disturbed sulfate homeostasis.

Exposure of the embryo or fetus to perturbations in utero can result in intrauterine growth restriction, a primary risk factor for the development of adult disease. However, despite similar exposures, males and females often have altered disease susceptibility or progression from different stages of life. Fetal growth is largely mediated by the placenta, which, like the fetus is genetically XX or XY. The placenta and its associated trophoblast lineages originate from the trophectoderm (TE) of the early embryo. Rodent models (rat, mouse, spiny mouse), have been used extensively to examine placenta development and these have demonstrated the growth trajectory of the placenta in females is generally slower compared to males, and also shows altered adaptive responses to stressful environments. These placental adaptations are likely to depend on the type of stressor, duration, severity and the window of exposure during development. Here we describe the divergent developmental pathways between the male and female placenta contributing to altered differentiation of the TE derived trophoblast subtypes, placental growth, and formation of the placental architecture. Our focus is primarily genetic or environmental pertur bations in rodent models which show altered placental responsiveness between sexes. We suggest that perturbations during early placental development may have greater impact on viability and growth of the female fetus whilst those occurring later in gestation may preferentially affect the male fetus. This may be of great relevance to human pregnancies which result from assisted reproductive technologies or complications such as pre-eclampsia and diabetes.

Normal placental function is essential for optimal fetal growth. Transport of glucose from mother to fetus is critical for fetal nutrient demands and can be stored in the placenta as glycogen. However, the function of this glycogen deposition remains a matter of debate: It could be a source of fuel for the placenta itself or a storage reservoir for later use by the fetus in times of need. While the significance of placental glycogen remains elusive, mounting evidence indicates that altered glycogen metabolism and/or deposition accompanies many pregnancy complications that adversely affect fetal development. This review will summarize histological, biochemical and molecular evidence that glycogen accumulates in a) placentas from a variety of experimental rodent models of perturbed pregnancy, including maternal alcohol exposure, glucocorticoid exposure, dietary deficiencies and hypoxia and b) placentas from human pregnancies with complications including preeclampsia, gestational diabetes mellitus and intrauterine growth restriction (IUGR). These pregnancies typically result in altered fetal growth, developmental abnormalities and/or disease outcomes in offspring. Collectively, this evidence suggests that changes in placental glycogen deposition is a common feature of pregnancy complications, particularly those associated with altered fetal growth.

Mg2+ regulates many physiological processes and signalling pathways. However, little is known about the mechanisms underlying the organismal balance of Mg2+. Capitalizing on a set of newly generated mouse models, we provide an integrated mechanistic model of the regulation of organismal Mg2+ balance during prenatal development and in adult mice by the ion channel TRPM6. We show that TRPM6 activity in the placenta and yolk sac is essential for embryonic development. In adult mice, TRPM6 is required in the intestine to maintain organismal Mg2+ balance, but is dispensable in the kidney. Trpm6 inactivation in adult mice leads to a shortened lifespan, growth deficit and metabolic alterations indicative of impaired energy balance. Dietary Mg2+ supplementation not only rescues all phenotypes displayed by Trpm6-deficient adult mice, but also may extend the lifespan of wildtype mice. Hence, maintenance of organismal Mg2+ balance by TRPM6 is crucial for prenatal development and survival to adulthood. DOI: http://dx.doi.org/10.7554/eLife.20914.001, eLife digest A balanced diet contains a variety of minerals such as magnesium ions, which are required for many chemical reactions in our body. A shortage of magnesium ions is linked to many diseases and is thought to be especially harmful to babies in the womb and shortly after birth. Magnesium ion deficiency is widespread in human populations and in the US is thought to affect up to 68% of people. Despite its prominent role in human health, our understanding of how the body maintains the right balance of magnesium ions remains extremely vague. Magnesium ions can enter and leave a cell by passing through specific types of proteins that form channels in the membrane surrounding the cell. There are thought to be around ten types of these magnesium ion channels in human cells, but we do not know what roles any of them perform in the body. One such channel called TRPM6 may be particularly important because mutations in the gene that encodes this channel can cause magnesium ion deficiency in human infants. However, the loss of TRPM6 in mice disrupts how mouse embryos develop, suggesting that our current view on the role that TRPM6 plays in regulating the magnesium ion balance in humans may be too simplistic. To address this question, Chubanov et al. studied mice with mutations that disrupted the production of TRPM6 in specific tissues only. The experiments show that TRPM6 primarily operates in the placenta and intestine to regulate the balance of magnesium ions in the body. Further experiments show that the loss of TRPM6 in adult mice leads to reduced lifespan, growth defects and poor health by disrupting important biochemical reactions. Supplying the mutant mice with magnesium ion supplements improved their health and could extend lifespans of normal animals. The findings of Chubanov et al. demonstrate that TRPM6 plays a crucial role in regulating the levels of magnesium ions in mice before birth and into adulthood. The next step is to carry out large-scale experiments to investigate the effects of altering the levels of magnesium ions in human diets. DOI: http://dx.doi.org/10.7554/eLife.20914.002

Maternal alcohol consumption is common prior to pregnancy recognition and in the rat results in altered placental development and fetal growth restriction. To assess the effect of ethanol (EtOH) exposure on the differentiation of trophoblast stem (TS) cells, mouse TS lines were differentiated in vitro for 6 days in 0%, 0.2% or 1% EtOH. This reduced both trophoblast survival and expression of labyrinth and junctional zone trophoblast subtype-specific genes. This suggests that fetal growth restriction and altered placental development associated with maternal alcohol consumption in the periconceptional period could be mediated in part by direct effects on trophoblast development.

Recently we reported that Rearranged L-Myc Fusion, RLF, acts as an epigenetic modifier maintaining low levels of DNA methylation at CpG island shores and enhancers across the genome. Here we focus on the phenotype of Rlf null mutant mice generated via an ENU mutagenesis screen, to identify genes required for epigenetic regulation. RLF is expressed in a range of fetal mouse tissues, including the fetal heart. Comprehensive timed-mating studies are consistent with our previously reported findings that Rlf homozygous mutant mice rarely survive to adulthood, with the majority dying shortly after birth. Histological analysis of two independent Rlf ENU mutant lines at E11.5-E14.5 showed heart defects resembling those present in humans with Left Ventricular Non-Compaction (LVNC). In situ hybridisation analysis localized expression of Rlf to the endocardium and epicardium of embryonic and postnatal hearts, and transiently to cardiomyocytes during heart looping and early chamber formation stages. RNA-seq analysis of Rlf mutant hearts highlighted defective NOTCH pathway signalling, recently describe as one cause of LVNC. This study provides the first evidence that RLF is required for normal heart development in the mouse. The heart morphological defects present at high penetrance in Rlf mutants are consistent with features of LVNC in humans, and molecular analysis identified attenuated JAGGED 1 expression and NOTCH signalling as likely contributors to these defects. Our study highlights the importance of RLF-dependent epigenetic modifications to DNA for maintaining correct gene regulatory network and intercellular signalling interactions during heart chamber and septal development. Further investigations are needed to define the biochemical role of RLF in the developing heart, and whether RLF mutations are a cause of heart defects in humans.

Insights into the anatomical organization of complex neural circuits provide important information about function, and thus tools that facilitate neuroanatomical studies have proved invaluable in neuroscience. Advances in molecular cloning have allowed the production of novel recombinant neuroinvasive viruses for use in transynaptic neural tracing studies. However, the vast majority of these viruses have motility in the retrograde direction only, therefore limiting their use to studies of synaptic input circuitry. Here we describe the construction of an EGFP reporting herpes simplex virus, strain H129, which preferentially moves along synaptically connected neurons in the anterograde direction. In vitro and in vivo characterization studies confirm that the HSV-1 H129-EGFP retains comparable replication and neuroinvasiveness as the wildtype H129 virus. As a proof of principle we confirm anterograde movement of the H129-EGFP along polysynaptic pathways by inoculating the upper airways and tracking time-dependent EGFP expression in previously described ascending sensory pathways. These data confirm a genomic locus for recombining HSV-1 H129 such that normal viral function and replication is maintained. Novel viral recombinants such as HSV-1 H129-EGFP will be useful tools for delineating the central organization of peripheral sensory pathways as well as the synaptic outputs from central neuronal populations.

The study of tourist decision-making usually focuses on destination choice, framed in terms of informational inputs into the rational decision-making processes of individuals. We report on a study of on-site tourist decision-making in the South Island of New Zealand. The framework within which decision-making is conceptualised draws on process accounts derived from work in naturalistic decision-making, and adaptive, situated and embodied cognition, and in this respect the study distinguishes itself from much previous work in this area. One hundred and forty qualitative interviews were analysed thematically to identify four dimensions of an emergent process of decision-making: (In)Flexibility; Location/timing; Social Composition; Stage of Trip. Decision-making varies on these dimensions in line with various ‘Types of Trip’ also identified from the data. This study provides support for process approaches to tourist decision-making and characterises it in terms of a continual process of socially mediated adjustment to features of the destination and overall trip evolution.

The Intergovernmental Panel on Climate Change has identified Australia as among the developed nations most at risk from climate change effects. Key tourism icon destinations and the tourism sector generally have been identified as being particularly at risk. This paper reports on an interdisciplinary, multi-case study approach to assess tourism stakeholders' knowledge of, and approaches to, climate change adaptation and to explore the potential for building a self-assessment toolkit that can be exported to other tourism destinations. This study examined existing knowledge on anticipated biophysical changes and, through primary research (stakeholder interviews and social learning workshops), gauged the expected adaptive approaches of destination communities and the tourism sector to these changes for 2020, 2050 and 2070. The facilitated workshops generated a common set of adaptation strategies across a diverse set of tourist destinations. A key finding from the workshops is that the tourism sector is not yet ready to invest in climate change adaptation because of the perceived uncertainties. Ongoing leadership for such measures were seen to rest with the public sector, especially local authorities. Whether such assessments can be self-generated or require specialist facilitation remains open to debate.

Sustainability assessments have become important tools for decision makers. This research assesses the sustainability of different types of tourists in New Zealand by using the concept of yield and by developing yield indicators in the areas of financial, public sector and sustainable yield. The concept and indicators have been developed in cooperation with the New Zealand tourism sector and therefore provide a sector-driven approach to implement a sustainability assessment. The analysis shows that there are numerous ‘trade-offs’ between indicators when attempting to define the ‘ideal visitor type’. Coach tourists, for example, are the largest spenders and generate the greatest Value Added in tourism on a per-day basis, but they contribute less to the financial sustainability of tourism when the costs of capital are accounted for. Coach tourists are highly concentrated in a few key destinations and at the same time produce substantial amounts of CO2 emissions due to their air travel component. In contrast, backpacker and camping tourists provide greater financial yield and are more dispersed, but they are also the greatest user of publicly provided tourist attractions and therefore come at a higher cost to government than other tourist types. Camping tourists are also contributing considerably to CO2 emissions. The yield analysis proposed in this paper could be a valuable tool for complex policy decision making and identifying strategies that lead to high-yield tourism.

Tourism has been increasingly used for, and directly linked with, rural poverty reduction in developing countries. However, the application, and to an extent the principles, of the widely used organising framework for considering poverty reduction, the Sustainable Livelihoods Approach (SLA), may not fit fully the tourism situation, and vice versa. Based on a review of the literature we first suggest that sustainable livelihoods for tourism should be viewed in a broader tourism context, rather than merely taking tourism as a development tool. Second, the SLA seeks household livelihood sustainability at the individual or household level, while tourism sustainability is often applied to the industry and destinations at wider, more macro level scales. Thus, a reconciliation of the tensions and opportunities between the SLA and tourism needs to be found. Third, tourism research has demonstrated local residents' increasing concern about participation in political governance associated with tourism development, with less participation jeopardising local people's assets from a livelihood perspective. Therefore, an additional concept of institutional asset (mainly community participation) needs to be incorporated within the SLA. Given the above understandings, a sustainable tourism livelihood was defined and a Sustainable Tourism Livelihoods Approach (STLA) is proposed. The potential applications of the STLA are discussed and future research is recommended.

Trophoblast giant cells (TGCs) are the first terminally differentiated subtype to form in the trophoblast cell lineage in rodents. In addition to mediating implantation, they are the main endocrine cells of the placenta, producing several hormones which regulate the maternal endocrine and immune systems and promote maternal blood flow to the implantation site. Generally considered a homogeneous population, TGCs have been identified by their expression of genes encoding placental lactogen 1 or proliferin. In the present study, we have identified a number of TGC subtypes, based on morphology and molecular criteria and demonstrated a previously underappreciated diversity of TGCs. In addition to TGCs that surround the implantation site and form the interface with the maternal deciduas, we demonstrate at least three other unique TGC subtypes: spiral artery-associated TGCs, maternal blood canal-associated TGCs and a TGC within the sinusoidal spaces of the labyrinth layer of the placenta. All four TGC subtypes could be identified based on the expression patterns of four genes: Pl1, Pl2, Plf (encoded by genes of the prolactin/prolactin-like protein/placental lactogen gene locus), and Ctsq (from a placental-specific cathepsin gene locus). Each of these subtypes was detected in differentiated trophoblast stem cell cultures and can be differentially regulated; treatment with retinoic acid induces Pl1/Plf+ TGCs preferentially. Furthermore, cell lineage tracing studies indicated unique origins for different TGC subtypes, in contrast with previous suggestions that secondary TGCs all arise from Tpbpa+ ectoplacental cone precursors.

The ubiquitously expressed zinc finger transcription factors Sp1 and Sp3 play critical roles in embryonic development. Sp1 knockout mice die around embryonic day 10.5. Mice lacking Sp3 are postnatal lethal. Mice heterozygous for either Sp1 or Sp3 are apparently normal, although slightly smaller. Here, we show that compound heterozygosity of Sp1 and Sp3 results in embryonic lethality accompanied by a spectrum of developmental abnormalities, including growth retardation, morphological alterations of the lung, impaired ossification, anemia, and placental defects. Anemia in Sp1/Sp3 compound heterozygous mutant embryos is associated with impaired maturation of erythrocytes. Analyses of the placenta revealed a markedly reduced spongiotrophoblast layer and a severe disorganization of the labyrinth layer in Sp1/Sp3 compound heterozygous as well as in Sp3-deficient mutant embryos. Our findings demonstrate that a threshold of Sp1 and Sp3 activity is required for normal embryonic development, suggesting that Sp1 and Sp3 act cooperatively to regulate downstream targets.

Through decentralization, local governments play an increasingly important role in tourism development. While there has been much research on local government's role in achieving sustainable tourism, relatively little research has been conducted on the capacity of local government to achieve sustainable tourism. This is particularly the case for developing countries such as Thailand. Applying the Nominal Group Technique and using in‐depth interviews with key stakeholders, this paper seeks to examine the capacity of a local Thai government administration, namely, the Tambon Administrative Authority (TAA). This research also examines the local government's influences on and responses to sustainable tourism development. The research findings demonstrate the TAA has adequate capacity in terms of legislative authority mandate, but limited capacity in terms of its resources including insufficient knowledge of tourism issues, budget and staffing. The paper concludes these limitations have resulted in a ...