Search

Large animals are severely depleted in many ecosystems, yet we are only beginning to understand the ecological implications of their loss. To empirically measure the short-term effects of removing large animals from an ocean ecosystem, we used exclosures to remove large fish from a near-pristine coral reef at Palmyra Atoll, Central Pacific Ocean. We identified a range of effects that followed from the removal of these large fish. These effects were revealed within weeks of their removal. Removing large fish (1) altered the behavior of prey fish; (2) reduced rates of herbivory on certain species of reef algae; (3) had both direct positive (reduced mortality of coral recruits) and indirect negative (through reduced grazing pressure on competitive algae) impacts on recruiting corals; and (4) tended to decrease abundances of small mobile benthic invertebrates. Results of this kind help advance our understanding of the ecological importance of large animals in ecosystems. © 2010 The Author(s).

Protected areas are a cornerstone of conservation strategies globally, yet questions remain about their impacts, including on highly migratory species. The Palmyra Atoll National Wildlife Refuge, one of the Northern Line Islands in the Central Pacific, contains a regionally significant green turtle Chelonia mydas foraging ground. Residency patterns of this species were investigated through satellite telemetry (n = 15 males, 1 female, 2 subadults) and flipper tagging (n = 555) between 2008 and 2013. Almost every captured turtle was flipper-tagged, but telemetry efforts focused primarily on adult males, which have been studied infrequently. Overall, the turtles tracked during 4076 transmission days (mean = 227, range = 37 to 633) had high site fidelity and small home ranges, and remained close to their capture sites in waters ≤50 m deep. Five turtles were tracked for >1 yr, but none left Palmyra on annual breeding migrations. Only one satellite-tracked turtle departed the atoll, covering a total distance of ~5600 km in a near-circular loop. Similarly, flipper tag recaptures on the atoll (n = 67) occurred near the original capture site. However, additional tags were recovered from 1 female in Kiritimati, Northern Line Islands, and from 1 subadult in Kosrae, Micronesia, ~690 and 3800 km away from Palmyra, respectively. Such extended, spatially restricted residency with low turnover is expected in small, high-quality habitats. The study highlights the importance of this protected area, which harbors regionally endangered turtles whose movements over several years are almost entirely encompassed within its established boundaries.

Sustained community spread of influenza viruses relies on efficient person-to-person transmission. Current experimental transmission systems do not mimic environmental conditions (e.g., air exchange rates, flow patterns), host behaviors, or exposure durations relevant to real-world settings. Therefore, results from these traditional systems may not be representative of influenza virus transmission in humans. To address this pitfall, we developed a close-range transmission setup that implements a play-based scenario and used it to investigate the impact of ventilation rates on transmission. In this setup, four immunologically naive recipient ferrets were exposed to a donor ferret infected with a genetically barcoded 2009 H1N1 virus (H1N1pdm09) for 4 h. The ferrets interacted in a shared space that included toys, similar to a childcare setting. Transmission efficiency was assessed under low and high ventilation, with air exchange rates of ~1.3 h -1 and 23 h -1 , respectively. Transmission efficiencies observed in three independent replicate studies were similar between ventilation conditions. The presence of infectious virus or viral RNA on surfaces and in air throughout the exposure area was also not impacted by the ventilation rate. While high viral genetic diversity in donor ferret nasal washes was maintained during infection, recipient ferret nasal washes displayed low diversity, revealing a narrow transmission bottleneck regardless of ventilation rate. Examining the frequency and duration of ferret physical touches revealed no link between these interactions and a successful transmission event. Our findings indicate that exposures characterized by frequent, close-range interactions and the presence of fomites can overcome the benefits of increased ventilation., Competing Interests: Competing interests statement:The authors declare no competing interest.

Objective: The authors report no conflicts of interest.To determine baseline sleep characteristics of male/female student-athletes across multiple sports using objective and subjective measures., Design: Prospective study., Setting: Division I college., Participants: Eighty-two male and female Division I student-athletes., Interventions: Participants completed 2 validated sleep questionnaires (Epworth Sleepiness Scale [ESS] and Single-Item Sleep Quality Scale [SISQS]) to assess subjective sleep. They also wore a validated sleep monitoring device (WHOOP 4.0 band) for at least 14 nights to collect objective data on total sleep time (TST) and sleep architecture., Main Outcome Measures: Overnight sleep variables, including TST, time spent awake in bed after falling asleep, time spent in light sleep, rapid eye movement (REM) sleep, and slow-wave sleep (SWS) cycles. Sleep quality and daytime sleepiness were also assessed., Results: There were no statistical differences between male and female student-athletes in average TST, sleep architecture, sleep consistency, SISQS, and ESS scores. The average TST was 409.2 ± 36.3 minutes. Sleep architecture consisted of 25.6% REM, 19.9% SWS, and 54.4% light sleep. The average sleep consistency was 61.6% ± 8.9%. The average SISQS score was 6.48 ± 1.71, and the average ESS score was 7.57 ± 3.82. A significant difference was found in average wake time between males and females (55.0 vs 43.7 min, P = 0.020), with an overall average of 50.2 ± 16.2 minutes., Conclusions: College student-athletes do not typically obtain the recommended amount of sleep. Optimizing sleep can positively affect academic and athletic performance., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: The goal of this exploratory study was to examine the relationships between sleep consistency and workplace resilience among soldiers stationed in a challenging Arctic environment., Materials and Methods: A total of 862 soldiers (67 females) on an Army base in Anchorage, AK, were provided WHOOP 3.0, a validated sleep biometric capture device and were surveyed at onboarding and at the conclusion of the study. Soldiers joined the study from early January to early March 2021 and completed the study in July 2021 (650 soldiers completed the onboarding survey and 210 completed the exit survey, with 151 soldiers completing both). Three comparative analyses were conducted. First, soldiers' sleep and cardiac metrics were compared against the general WHOOP population and a WHOOP sample living in AK. Second, seasonal trends (summer versus winter) in soldiers' sleep metrics (time in bed, hours of sleep, wake duration during sleep, time of sleep onset/offset, and disturbances) were analyzed, and these seasonal trends were compared with the general WHOOP population and the WHOOP sample living in AK. Third, soldiers' exertion, sleep duration, and sleep consistency were correlated with their self-reported psychological functioning. All analyses were conducted with parametric and non-parametric statistics. This study was approved by The University of Queensland Human Research Ethics Committee (Brisbane, Australia) Institutional Review Board., Results: Because of the exploratory nature of the study, the critical significance value was set at P < .001. Results revealed that: (1) Arctic soldiers had poorer sleep consistency and sleep duration than the general WHOOP sample and the Alaskan WHOOP sample, (2) Arctic soldiers showed a decrease in sleep consistency and sleep duration in the summer compared to that in the winter, (3) Arctic soldiers were less able to control their bedroom environment in the summer than in the winter, and (4) sleep consistency but not sleep duration correlated positively with self-report measures of workplace resilience and healthy social networks and negatively with homesickness., Conclusions: The study highlights the relationship between seasonality, sleep consistency, and psychological well-being. The results indicate the potential importance of sleep consistency in psychological functioning, suggesting that future work should manipulate factors known to increase sleep consistency to assess whether improved sleep consistency can enhance the well-being of soldiers. Such efforts would be of particular value in an Arctic environment, where seasonality effects are large and sleep consistency is difficult to maintain., (© The Association of Military Surgeons of the United States 2023.)

One potential advantage of live attenuated influenza vaccines (LAIVs) is their ability to establish both virus-specific Ab and tissue-resident memory T cells (TRM) in the respiratory mucosa. However, it is hypothesized that pre-existing immunity from past infections and/or immunizations prevents LAIV from boosting or generating de novo CD8+ T cell responses. To determine whether we can overcome this limitation, we generated a series of drifted influenza A/PR8 LAIVs with successive mutations in the hemagglutinin protein, allowing for increasing levels of escape from pre-existing Ab. We also inserted a CD8+ T cell epitope from the Sendai virus nucleoprotein (NP) to assess both generation of a de novo T cell response and boosting of pre-existing influenza-specific CD8+ T cells following LAIV immunization. Increasing the level of escape from Ab enabled boosting of pre-existing TRM, but we were unable to generate de novo Sendai virus NP+ CD8+ TRM following LAIV immunization in PR8 influenza-immune mice, even with LAIV strains that can fully escape pre-existing Ab. As these data suggested a role for cell-mediated immunity in limiting LAIV efficacy, we investigated several scenarios to assess the impact of pre-existing LAIV-specific TRM in the upper and lower respiratory tract. Ultimately, we found that deletion of the immunodominant influenza NP366-374 epitope allowed for sufficient escape from cellular immunity to establish de novo CD8+ TRM. When combined, these studies demonstrate that both pre-existing humoral and cellular immunity can limit the effectiveness of LAIV, which is an important consideration for future design of vaccine vectors against respiratory pathogens., (Copyright © 2023 by The American Association of Immunologists, Inc.)

Pre-sleep nutrition habits in elite female athletes have yet to be evaluated. A retrospective analysis was performed with 14 NCAA Division I female soccer players who wore a WHOOP, Inc. band - a wearable device that quantifies recovery by measuring sleep, activity, and heart rate metrics through actigraphy and photoplethysmography, respectively - 24 h a day for an entire competitive season to measure sleep and recovery. Pre-sleep food consumption data were collected via surveys every 3 days. Average pre-sleep nutritional intake (mean ± sd: kcals 330 ± 284; cho 46.2 ± 40.5 g; pro 7.6 ± 7.3 g; fat 12 ± 10.5 g) was recorded. Macronutrients and kcals were grouped into high and low categories based upon the 50 th percentile of the mean to compare the impact of a high versus low pre-sleep intake on sleep and recovery variables. Sleep duration ( p  = 0.10, 0.69, 0.16, 0.17) and sleep disturbances ( p  = 0.42, 0.65, 0.81, 0.81) were not affected by high versus low kcal, PRO, fat, CHO intake, respectively. Recovery ( p  = 0.81, 0.06, 0.81, 0.92), RHR ( p  = 0.84, 0.64, 0.26, 0.66), or HRV ( p  = 0.84, 0.70, 0.76, 0.93) were also not affected by high versus low kcal, PRO, fat, or CHO consumption, respectively. Consuming a small meal before bed may have no impact on sleep or recovery.

Objective: We sought to quantify the effects of in-house call(IHC) on sleep patterns and burnout among acute care surgeons (ACS)., Background: Many ACS take INC, which leads to disrupted sleep and high levels of stress and burnout., Methods: Physiological and survey data of 224 ACS with IHC were collected over 6 months. Participants continuously wore a physiological tracking device and responded to daily electronic surveys. Daily surveys captured work and life events as well as feelings of restfulness and burnout. The Maslach Burnout Inventory (MBI) was administered at the beginning and end of the study period., Results: Physiological data were recorded for 34,135 days, which includes 4389 nights of IHC. Feelings of moderate, very, or extreme burnout occurred 25.7% of days and feelings of being moderately, slightly, or not at all rested occurred 75.91% of days. Decreased amount of time since the last IHC, reduced sleep duration, being on call, and having a bad outcome all contribute to greater feelings of daily burnout ( P <0.001). Decreased time since last call also exacerbates the negative effect of IHC on burnout ( P <0.01)., Conclusions: ACS exhibit lower quality and reduced amount of sleep compared with an age-matched population. Furthermore, reduced sleep and decreased time since the last call led to increased feelings of daily burnout, accumulating in emotional exhaustion as measured on the MBI. A reevaluation of IHC requirements and patterns as well as identification of countermeasures to restore homeostatic wellness in ACS is essential to protect and optimize our workforce., Competing Interests: K.E.H. is a paid employee of and has an equity interest in WHOOP Inc. J.K. is a paid employee of WHOOP Inc. WHOOP Inc. had no financial interest in this study and did not participate in study design or approval of the results or manuscript. The remaining authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

When multiple viral populations propagate within the same host environment, they often shape each other's dynamics. These interactions can be positive or negative and can occur at multiple scales, from coinfection of a cell to co-circulation at a global population level. For influenza A viruses (IAVs), the delivery of multiple viral genomes to a cell substantially increases burst size. However, despite its relevance for IAV evolution through reassortment, the implications of this positive density dependence for coinfection between distinct IAVs has not been explored. Furthermore, the extent to which these interactions within the cell shape viral dynamics at the level of the host remains unclear. Here we show that, within cells, diverse coinfecting IAVs strongly augment the replication of a focal strain, irrespective of their homology to the focal strain. Coinfecting viruses with a low intrinsic reliance on multiple infection offer the greatest benefit. Nevertheless, virus-virus interactions at the level of the whole host are antagonistic. This antagonism is recapitulated in cell culture when the coinfecting virus is introduced several hours prior to the focal strain or under conditions conducive to multiple rounds of viral replication. Together, these data suggest that beneficial virus-virus interactions within cells are counterbalanced by competition for susceptible cells during viral propagation through a tissue. The integration of virus-virus interactions across scales is critical in defining the outcomes of viral coinfection., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Delima et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

As influenza A viruses (IAV) continue to cross species barriers and cause human infection, the establishment of risk assessment rubrics has improved pandemic preparedness efforts. In vivo pathogenicity and transmissibility evaluations in the ferret model represent a critical component of this work. As the relative contribution of in vitro experimentation to these rubrics has not been closely examined, we sought to evaluate to what extent viral titer measurements over the course of in vitro infections are predictive or correlates of nasal wash and tissue measurements for IAV infections in vivo . We compiled data from ferrets inoculated with an extensive panel of over 50 human and zoonotic IAV (inclusive of swine-origin and high- and low-pathogenicity avian influenza viruses associated with human infection) under a consistent protocol, with all viruses concurrently tested in a human bronchial epithelial cell line (Calu-3). Viral titers in ferret nasal wash specimens and nasal turbinate tissue correlated positively with peak titer in Calu-3 cells, whereas additional phenotypic and molecular determinants of influenza virus virulence and transmissibility in ferrets varied in their association with in vitro viral titer measurements. Mathematical modeling was used to estimate more generalizable key replication kinetic parameters from raw in vitro viral titers, revealing commonalities between viral infection progression in vivo and in vitro . Meta-analyses inclusive of IAV that display a diverse range of phenotypes in ferrets, interpreted with mathematical modeling of viral kinetic parameters, can provide critical information supporting a more rigorous and appropriate contextualization of in vitro experiments toward pandemic preparedness. IMPORTANCE Both in vitro and in vivo models are employed for assessing the pandemic potential of novel and emerging influenza A viruses in laboratory settings, but systematic examinations of how well viral titer measurements obtained in vitro align with results from in vivo experimentation are not frequently performed. We show that certain viral titer measurements following infection of a human bronchial epithelial cell line are positively correlated with viral titers in specimens collected from virus-inoculated ferrets and employ mathematical modeling to identify commonalities between viral infection progression between both models. These analyses provide a necessary first step in enhanced interpretation and incorporation of in vitro -derived data in risk assessment activities and highlight the utility of employing mathematical modeling approaches to more closely examine features of virus replication not identifiable by experimental studies alone.

Transmission efficiency is a critical factor determining the size of an outbreak of infectious disease. Indeed, the propensity of SARS-CoV-2 to transmit among humans precipitated and continues to sustain the COVID-19 pandemic. Nevertheless, the number of new cases among contacts is highly variable and underlying reasons for wide-ranging transmission outcomes remain unclear. Here, we evaluated viral spread in golden Syrian hamsters to define the impact of temporal and environmental conditions on the efficiency of SARS-CoV-2 transmission through the air. Our data show that exposure periods as brief as one hour are sufficient to support robust transmission. However, the timing after infection is critical for transmission success, with the highest frequency of transmission to contacts occurring at times of peak viral load in the donor animals. Relative humidity and temperature had no detectable impact on transmission when exposures were carried out with optimal timing and high inoculation dose. However, contrary to expectation, trends observed with sub-optimal exposure timing and lower inoculation dose suggest improved transmission at high relative humidity or high temperature. In sum, among the conditions tested, our data reveal the timing of exposure to be the strongest determinant of SARS-CoV-2 transmission success and implicate viral load as an important driver of transmission., Competing Interests: The authors have declared that no competing interests exist.

Reassortment of segmented viruses can be an important source of genetic diversity underlying viral evolution and emergence. Methods for the quantification of reassortment have been described but are often cumbersome and best suited for the analysis of reassortment between highly divergent parental strains. While it is useful to understand the potential of divergent parents to reassort, outcomes of such heterologous reassortment are driven by differential selection acting on the progeny and are typically strain specific. To quantify reassortment robustly, a system free of differential selection is needed. We have generated such a system for influenza A virus and for mammalian orthoreovirus by constructing well-matched parental viruses carrying small genetic tags. The method utilizes high-resolution melt technology for the identification of reassortant viruses. Ease of sample preparation and data analysis enables streamlined genotyping of a large number of virus clones. The method described here thereby allows quantification of the efficiency of reassortment and can be applied to diverse segmented viruses., (Copyright © 2020 Elsevier B.V. All rights reserved.)

We tested the effects of gestational stress, principally in the form of alarm cue extracted from the skin of conspecifics, on reproduction in female guppies (Poecilia reticulata) and the growth and behaviour of their offspring. Offspring from mothers exposed to alarm cue exhibited stunted growth in the first few days post-partum, which appeared to be mediated by shortening of the gestation period, the length of which directly correlated with growth rate within the first 6 days post-partum. Mature offspring did not differ in behaviour or stress responses compared with controls and so the effects of maternal predation stress did not appear to persist into adulthood. A different form of gestational stress, dietary restriction, did not significantly affect offspring growth, though brood size was reduced, suggesting that the effects of predation stress were not mediated by differences in resource demand or consumption., (© 2019 The Fisheries Society of the British Isles.)

An increased serum alkaline phosphatase concentration is known to be associated with a negative prognosis in canine and human osteosarcoma. To expand upon previous studies regarding the biological relevance of increased serum alkaline phosphatase as a negative prognostic factor, xenogeneic heterotopic transplants were performed using six canine primary osteosarcoma cell lines generated from patients with differing serum alkaline phosphatase concentrations (three normal and three increased). Three of the six cell lines were capable of generating tumours and tumour formation was independent of the serum alkaline phosphatase status of the cell line. Microarray analysis identified 379 genes as being differentially expressed between the tumourigenic and non-tumourigenic cell lines. Frizzled-6 was upregulated to the greatest extent (7.78-fold) in tumourigenic cell lines compared with non-tumourigenic cell lines. Frizzled-6, a co-receptor for Wnt ligands has been associated with enhanced tumour-initiating cells and poor prognosis for other tumours. The increased expression of frizzled-6 was confirmed by quantitative reverse transcription polymerase chain reaction (QPCR) and Western blot analysis. Additionally, the tumourigenic cell lines also had an increase in the percentage of side population cells compared with non-tumourigenic cell lines (5.89% versus 1.58%, respectively). There were no differences in tumourigenicity, frizzled-6 or percentage of side population cells noted between osteosarcoma cell lines generated from patients of differing serum alkaline phosphatase concentration. However, to our knowledge this is the first study to identified frizzled-6 as a possible marker of osteosarcoma cell populations with enhanced tumourigenicity and side population cells. Future work will focus on defining the role of frizzled-6 in osteosarcoma tumourigenesis and tumour-initiating cells., (© 2015 John Wiley & Sons Ltd.)

Ongoing declines in the structure and function of the world’s coral reefs require novel approaches to sustain these ecosystems and the millions of people who depend on them3. A presently unexplored approach that draws on theory and practice in human health and rural development is to systematically identify and learn from the ‘outliers’—places where ecosystems are substantially better (‘bright spots’) or worse (‘dark spots’) than expected, given the environmental conditions and socioeconomic drivers they are exposed to. Here we compile data from more than 2,500 reefs worldwide and develop a Bayesian hierarchical model to generate expectations of how standing stocks of reef fish biomass are related to 18 socioeconomic drivers and environmental conditions. We identify 15 bright spots and 35 dark spots among our global survey of coral reefs, defined as sites that have biomass levels more than two standard deviations from expectations. Importantly, bright spots are not simply comprised of remote areas with low fishing pressure; they include localities where human populations and use of ecosystem resources is high, potentially providing insights into how communities have successfully confronted strong drivers of change. Conversely, dark spots are not necessarily the sites with the lowest absolute biomass and even include some remote, uninhabited locations often considered near pristine6. We surveyed local experts about social, institutional, and environmental conditions at these sites to reveal that bright spots are characterized by strong sociocultural institutions such as customary taboos and marine tenure, high levels of local engagement in management, high dependence on marine resources, and beneficial environmental conditions such as deep-water refuges. Alternatively, dark spots are characterized by intensive capture and storage technology and a recent history of environmental shocks. Our results suggest that investments in strengthening fisheries governance, particularly aspects such as participation and property rights, could facilitate innovative conservation actions that help communities defy expectations of global reef degradation.

Serum alkaline phosphatase (ALP) concentration is a prognostic factor for osteosarcoma in multiple studies, although its biological significance remains incompletely understood. To determine whether gene expression patterns differed in osteosarcoma from patients with differing serum ALP concentrations, microarray analysis was performed on 18 primary osteosarcoma samples and six osteosarcoma cell lines from dogs with normal and increased serum ALP concentration. No differences in gene expression patterns were noted between tumours or cell lines with differing serum ALP concentration using a gene-specific two-sample t-test. Using a more sensitive empirical Bayes procedure, defective in cullin neddylation 1 domain containing 1 (DCUN1D1) was increased in both the tissue and cell lines of the normal ALP group. Using quantitative PCR (qPCR), differences in DCUN1D1 expression between the two groups failed to reach significance. The homogeneity of gene expression patterns of osteosarcoma associated differing serum ALP concentrations are consistent with previous studies suggesting serum ALP concentration is not associated with intrinsic differences of osteosarcoma cells., (© 2015 John Wiley & Sons Ltd.)

Osteosarcoma is an aggressive malignancy and represents the most frequent primary bone malignancy of dogs and humans. Prognostic factors reported for osteosarcoma include tumour size, presence of metastatic disease and serum alkaline phosphatase (ALP) concentration at the time of diagnosis. To date, there have been no studies to determine whether the behaviour of osteosarcoma cells differ based on serum ALP concentration. Here, we report on the generation of six canine osteosarcoma cell lines from osteosarcoma-bearing dogs with differences in serum ALP concentration. To determine whether in vitro behaviour differs between primary osteosarcoma cell lines generated from patients with normal or increased serum ALP, assays were performed to evaluate proliferation, migration, invasion and chemosensitivity. There were no significant differences in cell proliferation, migration, invasion or chemosensitivity between cell lines associated with normal or increased serum ALP concentration., (© 2013 Blackwell Publishing Ltd.)

Alterations in the Wnt signaling pathway are associated with diverse cancers, including hepatocellular carcinoma (HCC). The development of HCC is thought to be a multistage process in which multiple genetic alterations are necessary. Few studies have assessed the effect of aberrant Wnt signaling activity in association with other molecular alterations in HCC. Here we sought to determine whether co-overexpression of c-Myc or TGFα, 2 signaling molecules known to contribute to HCC development, enhanced the development of hepatic lesions associated with a stabilized β-catenin. The coexpression of mutant β-catenin with either c-Myc or TGFα within hepatocytes increased the severity of hepatic lesions compared with that associated with any of the transgenes expressed individually. The coexpression of mutant β-catenin with c-Myc or TGFα resulted in severe hepatomegaly necessitating the euthanasia of mice by an average of 156 and 128 d, respectively, after the cessation of doxycycline. The expression of mutant β-catenin alone resulted in mild to moderate hepatomegaly that prompted the euthanasia of mice by an average of 75 d after the cessation of doxycycline. Collectively, these findings indicate that coexpression of c-Myc or TGFα delays the onset of endstage hepatic disease yet enhances the severity of hepatic lesions due to mutant β-catenin.

Osteosarcoma (OSA) is the most frequently occurring malignant primary bone tumour in dogs and children and arises from cells of the osteoblast lineage. Inappropriate Wnt signalling activity has been implicated in human OSA. Altered expression of β-catenin, an integral member of the Wnt signalling pathway, has been associated with numerous human cancers, including OSA. In this study, 30 of the 37 primary canine OSA tissues and 2 of the 3 metastatic OSAs were positive for β-catenin expression as determined by immunohistochemistry, whereas 2 normal bones stained negative for β-catenin. No mutations were identified in exon 3 of β-catenin in the three OSA cases in which DNA sequencing was performed. Finally, there was no relationship between β-catenin expression and overall survival time or disease-free interval. Our results indicate β-catenin is frequently expressed within the cytoplasm of neoplastic cells in canine OSA but contains no detectable mutations in exon 3, similar to human OSA., (© 2010 Blackwell Publishing Ltd.)

Background: Mutations in the Wnt signalling pathway molecule β-catenin are associated with liver cancer., Aims: Our aim was to confirm the effects of stabilized β-catenin on liver growth, identify whether those effects were reversible and cell autonomous or non-cell autonomous and to model β-catenin-induced liver cancer in mice., Methods: Using a liver-specific inducible promoter, we generated transgenic mice in which the expression of mutant β-catenin can be induced or repressed within hepatocytes in mice of different ages., Results: Similar to other models, the hepatic expression of mutant β-catenin in our model beginning in utero or induced in quiescent adult liver resulted in a two-fold liver enlargement and development of disease with a latency of 1-5 months, and mice displayed elevated blood ammonia and altered hepatic gene expression. Our model additionally allowed us to discover that molecular and phenotypic abnormalities were reversible following the inhibition of transgene expression. Hepatocyte transplant studies indicated that mutant β-catenin could not increase the growth of transgene-expressing foci in either growth-permissive or -restrictive hepatic environments, but still directly altered hepatocyte gene expression. Mice with continuous but focal transgene expression developed hepatic neoplasms after the age of 1 year., Conclusions: Our findings indicate that hepatocyte gene expression is directly affected by mutant β-catenin in a cell autonomous manner. However, hepatomegaly associated with diffuse hepatocyte-specific expression of mutant β-catenin is secondary to liver functional alteration or non-cell autonomous. Both phenotypes are reversible. Nevertheless, some foci of transgene-expressing cells progressed to carcinoma, confirming the association of mutant β-catenin with liver cancer., (© 2011 John Wiley & Sons A/S.)

In recent years, electroporation has become a popular technique for in vivo transfection of DNA, RNA, and morpholinos into various tissues, including the eye, brain, and somites of zebrafish. The advantage of electroporation over other methods of genetic manipulation is that specific tissues can be targeted, both spatially and temporally, for the introduction of macromolecules by the application of electrical current. Here we describe the use of electroporation for transfecting mif and mif-like morpholinos into the tissues of the developing inner ear of the zebrafish. In past studies, mif morpholino injected into embryos at the 1- to 8-cell stage resulted in widespread morphological changes in the nervous system and eye, as well as the ear. By targeting the tissues of the inner ear at later stages in development, we can determine the primary effects of MIF in the developing inner ear, as opposed to secondary effects that may result from the influence of other tissues. By using phalloidin and acetylated tubulin staining to study the morphology of neurons, neuronal processes, and hair cells associated with the posterior macula, we were able to assess the efficacy of electroporation as a method for targeted transfection in the zebrafish inner ear. The otic vesicles of 24hpf embryos were injected with morpholinos and electroporated and were then compared to embryos that had received no treatment or had been only injected or electroporated. Embryos that were injected and electroporated showed a decrease in hair cell numbers, decreased innervation by the statoacoustic ganglion (SAG) and fewer SAG neurons compared with control groups. Our results showed that direct delivery of morpholinos into otocysts at later stages avoids the non-specific nervous system and neural crest effects of morpholinos delivered at the 1-8 cell stage. It also allows examination of effects that are directed to the inner ear and not secondary effects on the ear from primary effects on the brain, neural crest or periotic mesenchyme.

Habitat maps are frequently invoked as surrogates of biodiversity to aid the design of networks of marine reserves. Maps are used to maximize habitat heterogeneity in reserves because this is likely to maximize the number of species protected. However, the technique's efficacy is limited by intra-habitat variability in the species present and their abundances. Although communities are expected to vary among patches of the same habitat, this variability is poorly documented and rarely incorporated into reserve planning. To examine intra-habitat variability in coral-reef fishes, we generated a data set from eight tropical coastal habitats and six islands in the Bahamian archipelago using underwater visual censuses. Firstly, we provide further support for habitat heterogeneity as a surrogate of biodiversity as each predefined habitat type supported a distinct assemblage of fishes. Intra-habitat variability in fish community structure at scales of hundreds of kilometers (among islands) was significant in at least 75% of the habitats studied, depending on whether presence/absence, density, or biomass data were used. Intra-habitat variability was positively correlated with the mean number of species in that habitat when density and biomass data were used. Such relationships provide a proxy for the assessment of intra-habitat variability when detailed quantitative data are scarce. Intra-habitat variability was examined in more detail for one habitat (forereefs visually dominated by Montastraea corals). Variability in community structure among islands was driven by small, demersal families (e.g., territorial pomacentrid and labrid fishes). Finally, we examined the ecological and economic significance of intra-habitat variability in fish assemblages on Montastraea reefs by identifying how this variability affects the composition and abundances of fishes in different functional groups, the key ecosystem process of parrotfish grazing, and the ecosystem service of value of commercially important finfish. There were significant differences in a range of functional groups and grazing, but not fisheries value. Variability at the scale of tens of kilometers (among reefs around an island) was less than that among islands. Caribbean marine reserves should be replicated at scales of hundreds of kilometers, particularly for species-rich habitats, to capture important intra-habitat variability in community structure, function, and an ecosystem process.

Habitat maps are often the core spatially consistent data set on which marine reserve networks are designed, but their efficacy as surrogates for species richness and applicability to other conservation measures is poorly understood. Combining an analysis of field survey data, literature review, and expert assessment by a multidisciplinary working group, we examined the degree to which Caribbean coastal habitats provide useful planning information on 4 conservation measures: species richness, the ecological functions of fish species, ecosystem processes, and ecosystem services. Approximately one-quarter to one-third of benthic invertebrate species and fish species (disaggregated by life phase; hereafter fish species) occurred in a single habitat, and Montastraea-dominated forereefs consistently had the highest richness of all species, processes, and services. All 11 habitats were needed to represent all 277 fish species in the seascape, although reducing the conservation target to 95% of species approximately halved the number of habitats required to ensure representation. Species accumulation indices (SAIs) were used to compare the efficacy of surrogates and revealed that fish species were a more appropriate surrogate of benthic species (SAI = 71%) than benthic species were for fishes (SAI = 42%). Species of reef fishes were also distributed more widely across the seascape than invertebrates and therefore their use as a surrogate simultaneously included mangroves, sea grass, and coral reef habitats. Functional classes of fishes served as effective surrogates of fish and benthic species which, given their ease to survey, makes them a particularly useful measure for conservation planning. Ecosystem processes and services exhibited great redundancy among habitats and were ineffective as surrogates of species. Therefore, processes and services in this case were generally unsuitable for a complementarity-based approach to reserve design. In contrast, the representation of species or functional classes ensured inclusion of all processes and services in the reserve network.

Reduced fishing pressure and weak predator-prey interactions within marine reserves can create trophic cascades that increase the number of grazing fishes and reduce the coverage of macroalgae on coral reefs. Here, we show that the impacts of reserves extend beyond trophic cascades and enhance the process of coral recruitment. Increased fish grazing, primarily driven by reduced fishing, was strongly negatively correlated with macroalgal cover and resulted in a 2-fold increase in the density of coral recruits within a Bahamian reef system. Our conclusions are robust because four alternative hypotheses that may generate a spurious correlation between grazing and coral recruitment were tested and rejected. Grazing appears to influence the density and community structure of coral recruits, but no detectable influence was found on the overall size-frequency distribution, community structure, or cover of corals. We interpret this absence of pattern in the adult coral community as symptomatic of the impact of a recent disturbance event that masks the recovery trajectories of individual reefs. Marine reserves are not a panacea for conservation but can facilitate the recovery of corals from disturbance and may help sustain the biodiversity of organisms that depend on a complex three-dimensional coral habitat.

Since the mass mortality of the urchin Diadema antillarum in 1983, parrotfishes have become the dominant grazer on Caribbean reefs. The grazing capacity of these fishes could be impaired if marine reserves achieve their long-term goal of restoring large consumers, several of which prey on parrotfishes. Here we compare the negative impacts of enhanced predation with the positive impacts of reduced fishing mortality on parrotfishes inside reserves. Because large-bodied parrotfishes escape the risk of predation from a large piscivore (the Nassau grouper), the predation effect reduced grazing by only 4 to 8%. This impact was overwhelmed by the increase in density of large parrotfishes, resulting in a net doubling of grazing. Increased grazing caused a fourfold reduction in the cover of macroalgae, which, because they are the principal competitors of corals, highlights the potential importance of reserves for coral reef resilience.

Caribbean coral reef habitats, seagrass beds and mangroves provide important goods and services both individually and through functional linkages. A range of anthropogenic factors are threatening the ecological and economic importance of these habitats and it is vital to understand how ecosystem processes vary across seascapes. A greater understanding of processes will facilitate further insight into the effects of disturbances and assist with assessing management options. Despite the need to study processes across whole seascapes, few spatially explicit ecosystem-scale assessments exist. We review the empirical literature to examine the role of different habitat types for a range of processes. The importance of each of 10 generic habitats to each process is defined as its "functional value" (none, low, medium or high), quantitatively derived from published data wherever possible and summarised in a single figure. This summary represents the first time the importance of habitats across an entire Caribbean seascape has been assessed for a range of processes. Furthermore, we review the susceptibility of each habitat to disturbances to investigate spatial patterns that might affect functional values. Habitat types are considered at the scale discriminated by remotely-sensed imagery and we envisage that functional values can be combined with habitat maps to provide spatially explicit information on processes across ecosystems. We provide examples of mapping the functional values of habitats for populations of three commercially important species. The resulting data layers were then used to generate seascape-scale assessments of "hot spots" of functional value that might be considered priorities for conservation. We also provide an example of how the literature reviewed here can be used to parameterise a habitat-specific model investigating reef resilience under different scenarios of herbivory. Finally, we use multidimensional scaling to provide a basic analysis of the overall functional roles of different habitats. The resulting ordination suggests that each habitat has a unique suite of functional values and, potentially, a distinct role within the ecosystem. This review shows that further data are required for many habitat types and processes, particularly forereef and escarpment habitats on reefs and for seagrass beds and mangroves. Furthermore, many data were collected prior to the regional mass mortality of Diadema and Acropora, and subsequent changes to benthic communities have, in many cases, altered a habitat's functional value, hindering the use of these data for parameterising maps and models. Similarly, few data exist on how functional values change when environmental parameters, such as water clarity, are altered by natural or anthropogenic influences or the effects of a habitat's spatial context within the seascape. Despite these limitations, sufficient data are available to construct maps and models to better understand tropical marine ecosystem processes and assist more effective mitigation of threats that alter habitats and their functional values.

The reaction of (Me3SiNSN)2S with TeCl4 in CH2Cl2 affords Cl2TeS2N2 (1) and that of (Me3SiNSN)2Se with TeCl4 produces Cl2TeSeSN2 (2) in good yields. The products were characterized by X-ray crystallography, as well as by NMR and vibrational spectroscopy and EI mass spectrometry. The Raman spectra were assigned by utilizing DFT molecular orbital calculations. The pathway of the formation of five-membered Cl2TeESN2 rings by the reactions of (Me3SiNSN)2E with TeCl4 (E = S, Se) is discussed. The reaction of (Me3SiNSN)2Se with [PPh4]2[Pd2X6] yields [PPh4]2[Pd2(mu-Se2N2S)X4] (X = Cl, 4a; Br, 4b), the first examples of complexes of the (Se2N2S)2- ligand. In both cases, this ligand bridges the two palladium centers through the selenium atoms.

Investigations of the reactivity of the thio-crown [14]aneS(4) (1,4,8,11-tetrathiacyclotetradecane) towards the aminating agent o-mesitylsulfonylhydroxylamine have lead to the crystallization of 1lambda(4),4lambda(4),8lambda(4),11lambda(4)-tetrathiacyclotetradecane-1,4,7,10-tetraylidenetetraaminium tetrakis(2,4,6-trimethylbenzenesulfonate), C10H28N4S(4)4+.4C9H11O3S-. The compound crystallizes in a centrosymmetric space group, with half a formula unit in the asymmetric unit. All S atoms within the cationic component are aminated, with the four NH(2) substituents arranged in pairs on neighbouring S atoms on opposite faces of the crown. The macrocyclic cation in the compound forms hydrogen bonds with the 2,4,6-trimethylbenzenesulfonate anions to create chains, which are further linked into thick two-dimensional sheets.

During investigations into sulfide- and selenide-amination reactions using the aminating agent o-mesitylsulfonylhydroxylamine, the monoclinic, (I), and orthorhombic, (II), polymorphs of ammonium 2,4,6-trimethylbenzenesulfonate, NH4+.C9H11O3S-, have been crystallized. Investigation of the hydrogen-bonding motifs within the two polymorphs shows that both contain N+-H...O- hydrogen bonds between the ammonium cations and the 2,4,6-trimethylbenzenesulfonate anions. Polymorph (I) contains R(4)(4)(12) and R(4)(2)(8) graph-set ring motifs, while polymorph (II) contains the same R(4)(4)(12) ring motif in combination with an R(4)(3)(10) motif. The two hydrogen-bonding patterns result in slightly different packing structures for the two polymorphs, but both are based on a thick-sheet arrangement, in which the NH4+ cations are enveloped between two layers of 2,4,6-trimethylbenzenesulfonate anions. In (I), the aromatic rings of the anions are approximately coplanar, giving parallel sheets, whereas in (II) the sheets are antiparallel and the anions pack in a herring-bone manner within the sheets, with angles of 78.76 (8) degrees between the planes of the aromatic rings.

The title compound, C24H20NSSe+.C24H20B-, exhibits disorder (S/Se scrambling) of the chalcogen sites within the S-N-Se triad. Similar disorder was observed in the bromide salt [Aucott, Bailey, Elsegood, Gilby, Holmes, Kelly, Papageorgiou & Pedron-Haba (2004). New J. Chem. pp. 959-966]. The S-N and Se-N bond lengths are 1.6735 (15) and 1.8045 (14) A, respectively. Whereas the chalcogens in the bromide salt are involved in S...Br and Se...Br interactions of very similar distances, the scrambled S and Se sites in the title compound are involved in distinct non-bonded interactions. The site predominantly occupied by sulfur is involved in C-H...S/Se interactions, while the site predominantly occupied by selenium is involved in Se/S...pi interactions.

The title compound, (C30H25NPS)2[Pd2Br6] or (Ph3PNSPh2)2[Pd2Br6], was crystallized from the reaction of (Ph3PNSPh2)[BPh4] with (PPh4)2[Pd2Br6], giving a salt rather than the intended coordination complex [PdBr3(Ph3PNSPh2)]. The compound crystallizes in the non-centrosymmetric space group Cc with one complete formula unit in the asymmetric unit. One of the two independent cations is disordered. The geometry of the two cations is compared with that of the only previously crystallized example of this cation, viz. its [SbCl6]- salt [Reck et al. (1982). Chem. Ber. 115, 2981-2996]. The bond angles within the P-N-S triad in the two cations in the title compound are narrower than those observed in the literature example, while the S-N bond lengths are slightly longer in the title compound. The P-N bond length in the ordered cation shows excellent agreement with that determined by Reck and co-workers, but the P-N bond lengths are lengthened slightly in the disordered cation. Weak C-H...Br interactions create a three-dimensional network, with cations and anions alternating along the crystallographic c direction.

Investigations into the effects of the choice of anion on the hydrogen-bonding interactions between anions and metal-sulfimide cationic complexes have led to the study of three novel compounds. Hexakis(S,S-diphenylsulfimide)cobalt(II) diiodide S,S-diphenylsulfimide acetonitrile disolvate, [Co(C12H11NS)6]I2.C12H11NS.2C2H3N, crystallizes in the centrosymmetric space group P-1 with Z = 2. Six diphenylsulfimide ligands coordinate to the cobalt centre through their N atoms. Two iodide counter-ions hydrogen bond to the cation through N-H...I interactions, with N...I distances in the range 3.7302 (19)-3.8461 (19) A. One extra molecule of sulfimide is included in the asymmetric unit, regardless of the metal-ligand ratio used in the synthesis, and this sulfimide molecule also hydrogen bonds to one of the iodide counter-ions through one N-H...I hydrogen bond. The reaction of FeCl3.6H2O with S,S-diphenylsulfimide monohydrate yields hexakis(S,S-diphenylsulfimide)iron(III) trichloride, [Fe(C12H11NS)6]Cl3. The complex crystallizes in the centrosymmetric cubic space group Pa-3 and the asymmetric unit contains one-sixth of a formula unit. Two of the chloride anions each hydrogen bond to three sulfimide NH groups on opposite sides of the [Fe(Ph2SNH)6]3+ cation. The third chloride anion does not take part in any strong hydrogen bonding; instead it is surrounded by aromatic groups and is involved in C-H...Cl hydrogen bonds. The reaction of [Pt(Ph2SNH)4]Cl2 with I2 facilitates oxidation of the Pt(II) metal centre to Pt(IV), producing tetrakis(S,S-diphenylsulfimide)diiodoplatinum(IV) dichloride dichloromethane disolvate, [PtI2(C12H11NS)4]Cl2.2CH2Cl2. The crystal structure is centrosymmetric, with the elongated octahedral cationic complex situated on an inversion centre. The chloride anions are hydrogen bonded to the cation through N-H...Cl hydrogen bonds, with two cis NH groups hydrogen bonded to each anion. Strong hydrogen bonding within these three compounds is limited to N-H...halide hydrogen bonds between the cation and two anions, with a three-up/three-down arrangement of the NH groups in the first two compounds. The anions also 'cap' the NH groups in the third compound. In all three cases, the anions are also involved in weaker hydrogen bonds utilizing the plethora of relatively acidic aryl CH groups in the structures.

The reaction of Se(4)N(4) with (Bu(4)N)(2)[Pd(2)Br(6)] gives the title compound, (C(16)H(36)N)(2)[Pd(2)Br(6)(N(2)Se(2))], in good yield. The [Pd(2)(Se(2)N(2))Br(6)](2-) anion lies on an inversion centre, and therefore the asymmetric unit contains half a formula unit. The crystal structure confirms the coordination of the Se(2)N(2) unit to Pd through the N atoms, as previously assigned by IR spectroscopic analysis [Kelly, Slawin & Soriano-Rama (1997). J. Chem. Soc. Dalton Trans. pp. 559-562]. The title compound contains the longest Pd-N bond so far observed for such systems.

Reaction of a solution of CuSO(4) and S,S'-diphenylsulfimide, Ph(2)SNH 1, with sodium salts of trimesic acid (H(3)tma) in MeOH gives the 2-D coordination network [Cu(3)(Ph(2)SNH)(6)(tma)(2)] in which each trimesate is bound to three copper centres. Addition of other solvents to the reaction mixture causes a change in the shape of the network. By this route, three forms have been prepared and characterised by X-ray crystallography. These include the known honeycomb, 2, and brick-wall, 3, motifs and a herringbone, 4, arrangement which is novel for transition metal-containing trimesate complexes. Key to the supramolecular isomerism observed is the ability of 1 to facilitate structural isomerism at copper(II) centres. In contrast to 2 in which the copper centres are square planar, 4 is analogous to an inter-allogon, with both planar and tetrahedral copper centres. Also prepared is a related complex which is composed of discrete units of three copper centres. These are further linked into a 2-D network by hydrogen bonds.

Pt(IV)-mediated addition of the sulfimide Ph2S = NH and the mixed sulfide/sulfimides o- and p-[PhS(=NH)](PhS)-C6H4 by the S=NH group to the metal-bound nitriles in the platinum(IV) complexes [PtCl4(RCN)2] proceeds smoothly at room temperature in CH2Cl2 and results in the formation of the heterodiazadiene compounds [PtCl4[NH=C(R)N=SR'Ph]2] (R' = Ph, R = Me, Et, CH2Ph, Ph; R' = o- and p-(PhS)C6H4; R = Et). While trans-[PtCl4(RCN)2] (R = Et, CH2Ph, Ph) reacting with Ph2S=NH leads exclusively to trans-[PtCl4[NH=C(R)N=SPh2]2], cis/trans-[PtCl4(MeCN)2] leads to cis/trans mixtures of [PtCl4[NH=C(Me)N=SPh2]2] and the latter have been separated by column chromatography. Theoretical calculations at both HF/HF and MP2//HF levels for the cis and trans isomers of [PtCl4[NH=C(Me)N=SMe2]2] indicate a higher stability for the latter. Compounds trans-[PtCl4[E-NH=C(R)N=SPh2]2] (R = Me, Et) and cis-[PtCl4[E-NH=C(Me)N=SPh2][Z-NH=C(Me)N=SPh2]] have been characterized by X-ray crystallography. The complexes [PtCl4[NH=C(R)N=SPh2]2] undergo hydrolysis when treated with HCl in nondried CH2Cl2 to achieve the amidines [PtCl4[NH=C(NH2)R]2] the compound with R = Et has been structurally characterized) and Ph2SO. The heterodiazadiene ligands, formed upon Pt(IV)-mediated RCN/sulfimide coupling, can be liberated from their platinum(IV) complexes [PtCl4[NH=C(R)N=SR'Ph]2] by reaction with Ph2PCH2CH2PPh2 (dppe) giving free NH=C(R)=SR'Ph and the dppe oxides, which constitutes a novel route for such rare types of heterodiazadienes whose number has also been extended. The hybrid sulfide/sulfimide species o- and p-[PhS(=NH)](PhS)C6H4 also react with the Pt(II) nitrile complex [PtCl2(MeCN)2] but the coupling--in contrast to the Pt(IV) species--gives the chelates [PtCl2[M-I=C(Me)N=S(Ph)C6H4SPh]]. The X-ray crystal structure of [PtCl2[M-I=C(Me)N=S(Ph)C6H4SPh-o]] reveals the bond parameters within the metallacycle and shows an unusual close interaction of the sulfide sulfur atom with the platinum.