Beyond population engagement: understanding counterinsurgency

The US military has made considerable progress in developing counterinsurgency (COIN) strategy and doctrine, including the publication of Army Field Manual 3-24 and the military's successes in working with the population to stem the insurgency in Iraq. The short-term goals of COIN are now fairly well understood: engage the population and win their support. Whichever side wins the support of the population--either the host nation (and US forces that support it) or the insurgents--wins the battle. The battle is not the war, however. the long-term goal of a counterinsurgency campaign requires the creation of a functioning state, a government that can stand on its own, provide for its citizens, and promote regional and international stability; this achievement is victory in a counterinsurgency. Transitioning from the short-term success of population engagement to long-term viability of the host nation is far more difficult and less understood

Physiological beta-catenin signaling controls self-renewal networks and generation of stem-like cells from nasopharyngeal carcinoma

BACKGROUND: A few reports suggested that low levels of Wnt signaling might drive cell reprogramming, but these studies could not establish a clear relationship between Wnt signaling and self-renewal networks. There are ongoing debates as to whether and how the Wnt/beta-catenin signaling is involved in the control of pluripotency gene networks. Additionally, whether physiological beta-catenin signaling generates stem-like cells through interactions with other pathways is as yet unclear. The nasopharyngeal carcinoma HONE1 cells have low expression of beta-catenin and wild-type expression of p53, which provided a possibility to study regulatory mechanism of stemness networks induced by physiological levels of Wnt signaling in these cells. RESULTS: Introduction of increased beta-catenin signaling, haploid expression of beta-catenin under control by its natural regulators in transferred chromosome 3, resulted in activation of Wnt/beta-catenin networks and dedifferentiation in HONE1 hybrid cell lines, but not in esophageal carcinoma SLMT1 hybrid cells that had high levels of endogenous beta-catenin expression. HONE1 hybrid cells displayed stem cell-like properties, including enhancement of CD24(+) and CD44(+) populations and generation of spheres that were not observed in parental HONE1 cells. Signaling cascades were detected in HONE1 hybrid cells, including activation of p53- and RB1-mediated tumor suppressor pathways, up-regulation of Nanog-, Oct4-, Sox2-, and Klf4-mediated pluripotency networks, and altered E-cadherin expression in both in vitro and in vivo assays. qPCR array analyses further revealed interactions of physiological Wnt/beta-catenin signaling with other pathways such as epithelial-mesenchymal transition, TGF-beta, Activin, BMPR, FGFR2, and LIFR- and IL6ST-mediated cell self-renewal networks. Using beta-catenin shRNA inhibitory assays, a dominant role for beta-catenin in these cellular network activities was observed. The expression of cell surface markers such as CD9, CD24, CD44, CD90, and CD133 in generated spheres was progressively up-regulated compared to HONE1 hybrid cells. Thirty-four up-regulated components of the Wnt pathway were identified in these spheres. CONCLUSIONS: Wnt/beta-catenin signaling regulates self-renewal networks and plays a central role in the control of pluripotency genes, tumor suppressive pathways and expression of cancer stem cell markers. This current study provides a novel platform to investigate the interaction of physiological Wnt/beta-catenin signaling with stemness transition networks.published_or_final_versio

Tissue-specific transcriptome assemblies of the marine medaka Oryzias melastigma and comparative analysis with the freshwater medaka Oryzias latipes

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Effects of hypoxia on growth of the diatom Skeletonema costatum

Hypoxia, defined as dissolved oxygen falls below 2.8mg O 2 L -1, affects several 100,000km 2 of marine water worldwide. Previous studies have shown that hypoxia results in aberrant behaviors of benthic fauna, collapse of fisheries, and major changes in the structure and trophodynamics of marine ecosystems. Nevertheless, it is not known whether, and if so how, hypoxia can affect the phytoplankton, which accounts for the major part of the primary productivity of marine ecosystems. The present study investigated the effects of hypoxia on the growth of the diatom Skeletonema costatum. Diatoms were cultured at three levels of oxygen (i.e. 7.0, 2.0, 0.5mg O 2 L -1) for 14days, and the biological endpoints (i.e. cell size, cell density, optical density, chlorophyll a concentration, adenylate energy charge) were measured at 0, 1, 3, 5, 7, and 14days. Our results demonstrated that all metrics and the calculated specific growth rate over the 14day experimental period were negatively affected by 0.5mg O 2 L -1. Results of this study, for the first time, provided the evidence and important insight of the impacts of hypoxia on the functions of phytoplankton in marine ecosystems. © 2012 Elsevier B.V.link_to_subscribed_fulltex

Effects of 1,2-dichlorobenzene on the growth, bioenergetics and reproduction of the amphipod, Melita longidactyla

The amphipod Melita longidactyla occurs in great abundance and serves important roles in the trophic transfer and nutrient recycling in marine systems along the Chinese coast. This study investigated the lethal dose (48h LC 50), as well as sub-lethal effects of a common xenobiotic, 1,2-dichlorobenzene (1,2-DCB), on the bioenergetics, growth and reproduction of this important species. The 48h LC 50 for M. longidactyla exposed to 1,2-DCB was 780μgL -1. Exposure to 20μgL -1 1,2-DCB for 3weeks resulted in 22% reduction in the growth (dry weight) and 57% reduction in the number of progeny, respectively. Furthermore, a significant reduction in RNA:DNA ratio was observed in amphipods exposed to 1,2-DCB at concentration as low as 5μgL -1, whereas significant reductions in scope for growth occurred upon exposure to higher concentrations of 1,2-DCB (10 and 20μgL -1) for 3 and 5weeks. Our results showed that environmentally relevant concentrations of 1,2-DCB can affect the bioenergetics and more importantly, growth and reproduction of M. longidactyla, implicating that 1,2-DCB may affect the recruitment and sustainability of natural populations of this ecologically important species. © 2010.link_to_subscribed_fulltex

Can a scavenging gastropod with a mussel conspecific diet induce anti-predator defence in the mussel Perna viridis?

This study investigated whether a mussel predator (the swimming crab Thalamita danae) and a scavenger (the gastropod Babylonia lutosa) could induce anti-predator response in the green-lipped mussel Perna viridis by chemical means. The crabs and gastropods had been either starved or recently fed with the mussels. We examined the number, diameter, length and volume of byssus threads produced by the mussels in order to compare the intensity of anti-predator responses when they were exposed to different stimuli. Our results showed that the mussels produced a significantly larger volume of byssus threads when they were exposed to a crab that had recently consumed conspecifics than the mussels in the control group. The starved crab had a weak effect on increasing the number, length, diameter and volume of byssus threads. Furthermore, the scavenging gastropods failed to increase byssus thread production in the mussels, no matter they had been starved or consumed conspecifics. Indeed, byssus thread production is energetically costly. It would be maladaptive for the mussels to increase byssus thread production in response to a low predation risk presented by a scavenger. © 2011 Elsevier B.V.link_to_subscribed_fulltex

Differential timing of larval starvation effects on filtration rate and growth in juvenile Crepidula onyx

This study demonstrates that the timing of larval starvation did not only determine the larval quality (shell length, lipid content, and RNA:DNA ratio) and the juvenile performance (growth and filtration rates), but also determine how the latent effects of larval starvation were mediated in Crepidula onyx. The juveniles developed from larvae that had experienced starvation in the first two days of larval life had reduced growth and lower filtration rates than those developed from larvae that had not been starved. Lower filtration rates explained the observed latent effects of early larval starvation on reduced juvenile growth. Starvation late in larval life caused a reduction in shell length, lipid content, and RNA:DNA ratio of larvae at metamorphosis; juveniles developed from these larvae performed poorly in terms of growth in shell length and total organic carbon content because of "depletion of energy reserves" at metamorphosis. Results of this study indicate that even exposure to the same kind of larval stress (starvation) for the same period of time (2 days) can cause different juvenile responses through different mechanisms if larvae are exposed to the stress at different stages of the larval life. © 2008 Springer-Verlag.link_to_subscribed_fulltex

Qualitative and quantitative changes in marine biofilms as a function of temperature and salinity in summer and winter

This study examined quantitative (dry weight, chlorophyll a content and C:N ratio) and qualitative (community compositions of bacteria and diatoms) changes in marine biofilms as a function of season (summer 2003 and winter 2004), temperature (16, 23 and 30°C) and salinity (20‰, 27‰ and 34‰) under laboratory conditions. Biofilms were allowed to develop for 20 days in the laboratory, using natural sea water collected from Port Shelter, Hong Kong. The following results were obtained: (1) biofilm dry weight was greater in summer than in winter, and greater at 34‰ than at 20‰; (2) biofilm chlorophyll a content was affected by all three factors (season, temperature and salinity), with significant interactive effects among the three factors; and (3) C:N ratio was affected by season (winter > summer) and temperature (30°C > 16°C in summer), but not by salinity. Bacterial community composition was analyzed by terminal restriction-fragment length polymorphism of polymerase chain reaction-amplified 16S rRNA genes. In summer, community compositions of both bacteria and diatoms were strongly affected by salinity. In addition, natural summer biofilms that developed at three field sites, where different salinities were found, harbored appreciably different bacterial and diatom community compositions. In contrast, in winter, temperature exerted a major influence on community compositions. The present study adds to the growing evidence that environmental factors are important determinants of both the quality and quantity of marine biofilms. © 2006 Cambridge University Press.link_to_subscribed_fulltex