96 research outputs found
Desmin is essential for the structure and function of the sinoatrial node:implications for increased arrhythmogenesis
Our objective was to investigate the effect of desmin depletion on the structure and function of the sinoatrial pacemaker complex (SANcl) and its implication in arrhythmogenesis. Analysis of mice and humans (SANcl) indicated that the sinoatrial node exhibits high amounts of desmin, desmoplakin, N-cadherin, and β-catenin in structures we call “lateral intercalated disks” connecting myocytes side by side. Examination of the SANcl from an arrhythmogenic cardiomyopathy model, desmin-deficient (Des-/-) mouse, by immunofluorescence, ultrastructural, and Western blot analysis showed that the number of these lateral intercalated disks was diminished. Also, electrophysiological recordings of the isolated compact sinoatrial node revealed increased pacemaker systolic potential and higher diastolic depolarization rate compared with wild-type mice. Prolonged interatrial conduction expressed as a longer P wave duration was also observed in Des-/mice. Upregulation of mRNA levels of both T-type Ca2+ current channels, Cav3.1 and Cav3.2, in the Des-/- myocardium (1.8- and 2.3-fold, respectively) and a 1.9-fold reduction of funny hyperpolarization-activated cyclic nucleotide-gated K+ channel 1 could underlie these functional differences. To investigate arrhythmogenicity, electrocardiographic analysis of Des-deficient mice revealed a major increase in supraventricular and ventricular ectopic beats compared with wild-type mice. Heart rate variability analysis indicated a sympathetic predominance in Des-/- mice, which may further contribute to arrhythmogenicity. In conclusion, our results indicate that desmin elimination leads to structural and functional abnormalities of the SANcl. These alterations may be enhanced by the sympathetic component of the cardiac autonomic nervous system, which is predominant in the desmin-deficient heart, thus leading to increased arrhythmogenesis
Aphrati and Kato Syme: Pottery, Continuity, and Cult in Late Archaic and Classical Crete
The analysis of ceramics from Aphrati sheds valuable new light on the history of this Cretan settlement and on its relationship with a nearby rural sanctuary at Kato Syme in the Late Archaic and Classical periods. It has long been held that Aphrati was deserted from ca. 600 to 400 B.C. A pottery deposit from the domestic quarter, however, now supports occupation of the city during this period. A ceramic classification system is presented and the morphological development and absolute chronology of several key shapes at Aphrati and Kato Syme are plotted. Historical implications of the ceramic evidence are also explored
Nine Months of Hybrid Intradialytic Exercise Training Improves Ejection Fraction and Cardiac Autonomic Nervous System Activity.
Cardiovascular disease is the most common cause of death in hemodialysis (HD) patients. Intradialytic aerobic exercise training has a beneficial effect on cardiovascular system function and reduces mortality in HD patients. However, the impact of other forms of exercise on the cardiovascular system, such as hybrid exercise, is not clear. Briefly, hybrid exercise combines aerobic and strength training in the same session. The present study examined whether hybrid intradialytic exercise has long-term benefits on left ventricular function and structure and the autonomous nervous system in HD patients. In this single-group design, efficacy-based intervention, twelve stable HD patients (10M/2F, 56 ± 19 years) participated in a nine-month-long hybrid intradialytic training program. Both echocardiographic assessments of left ventricular function and structure and heart rate variability (HRV) were assessed pre, during and after the end of the HD session at baseline and after the nine-month intervention. Ejection Fraction (EF), both assessed before and at the end of the HD session, appeared to be significantly improved after the intervention period compared to the baseline values (48.7 ± 11.1 vs. 58.8 ± 6.5, p = 0.046 and 50.0 ± 13.4 vs. 56.1 ± 3.4, p = 0.054 respectively). Regarding HRV assessment, hybrid exercise training increased LF and decreased HF (p p > 0.05). In conclusion, long-term intradialytic hybrid exercise training was an effective non-pharmacological approach to improving EF and the cardiac autonomous nervous system in HD patients. Such exercise training programs could be incorporated into HD units to improve the patients' cardiovascular health
Lutzomyia Sand Fly Diversity and Rates of Infection by Wolbachia and an Exotic Leishmania Species on Barro Colorado Island, Panama
Certain sand fly species living inside or on the edge of tropical forests are well known to transmit a protozoan to humans, which in lowland Panama develops into a cutaneous form of leishmaniasis; open, itching sores on the face and extremities requiring aggressive treatment with antimonial compounds. Morphological characters and DNA sequence from mitochondrial and nuclear gene fragments permitted us to identify and then establish historical relationships among 20 common sand fly species occurring in the understory of Barro Colorado Island, a forested preserve in the middle of the Panama Canal. Individuals in three of these sand fly species were found to be 26–43% infected by Leishmania naiffi, a species hitherto known only from the Amazonian region and the Caribbean. We then screened the same 20 sand fly species for the cytoplasmically transmitted bacteria Wolbachia pipientis, finding three infected at high rates, each by a distinct strain. Lutzomyia trapidoi, the most likely transmitter of Leishmania to humans in Panama, was among the Wolbachia-infected species, thus marking it as a possible high-value target for future biocontrol studies using the bacteria either to induce mating incompatabilities or to drive selected genes into the population
Using systems thinking and open innovation to strengthen aquaculture policy for the United Nations Sustainable Development Goals
In a world of nine billion people and a widening income gap between the rich and poor, it is time to rethink how aquaculture can strengthen its contribution to the second UN Sustainable Development Goal (SDG) of zero hunger in our generation. The disparity in the level of sustainable aquaculture development at present, between and within countries, especially regarding human access to farmed aquatic food remains highly variable across the globe. This paper offers a fresh look at the opportunities from using systems thinking and new open innovation measuring tools to grow sustainable aquaculture. Political will in many nations is the main constraint to aquaculture in realising its potential as an: accessible source of micronutrients and nutritious protein; aid to meeting conservation goals; economic prosperity generator where benefits extend to locals and provider of indirect social benefits such as access to education and well‐being, among others. Resources to enable strong partnerships (SDG 17) between academia, civic society, government and industry should be prioritised by governments to build a sustainable aquatic food system, accessible to all, forever
Cutaneous Leishmaniasis and Sand Fly Fluctuations Are Associated with El Nino in Panama
BackgroundCutaneous Leishmaniasis (CL) is a neglected tropical vector-borne disease. Sand fly vectors (SF) and Leishmania spp parasites are sensitive to changes in weather conditions, rendering disease transmission susceptible to changes in local and global scale climatic patterns. Nevertheless, it is unclear how SF abundance is impacted by El Nino Southern Oscillation (ENSO) and how these changes might relate to changes in CL transmission.Methodology and FindingsWe studied association patterns between monthly time series, from January 2000 to December 2010, of: CL cases, rainfall and temperature from Panama, and an ENSO index. We employed autoregressive models and cross wavelet coherence, to quantify the seasonal and interannual impact of local climate and ENSO on CL dynamics. We employed Poisson Rate Generalized Linear Mixed Models to study SF abundance patterns across ENSO phases, seasons and eco-epidemiological settings, employing records from 640 night-trap sampling collections spanning 2000?2011. We found that ENSO, rainfall and temperature were associated with CL cycles at interannual scales, while seasonal patterns were mainly associated with rainfall and temperature. Sand fly (SF) vector abundance, on average, decreased during the hot and cold ENSO phases, when compared with the normal ENSO phase, yet variability in vector abundance was largest during the cold ENSO phase. Our results showed a three month lagged association between SF vector abundance and CL cases.ConclusionAssociation patterns of CL with ENSO and local climatic factors in Panama indicate that interannual CL cycles might be driven by ENSO, while the CL seasonality was mainly associated with temperature and rainfall variability. CL cases and SF abundance were associated in a fashion suggesting that sudden extraordinary changes in vector abundance might increase the potential for CL epidemic outbreaks, given that CL epidemics occur during the cold ENSO phase, a time when SF abundance shows its highest fluctuations
Stable Isotope Evidence for Dietary Overlap between Alien and Native Gastropods in Coastal Lakes of Northern KwaZulu-Natal, South Africa
Tarebia granifera (Lamarck, 1822) is originally from South-East Asia, but has been introduced and become invasive in many tropical and subtropical parts of the world. In South Africa, T. granifera is rapidly invading an increasing number of coastal lakes and estuaries, often reaching very high population densities and dominating shallow water benthic invertebrate assemblages. An assessment of the feeding dynamics of T. granifera has raised questions about potential ecological impacts, specifically in terms of its dietary overlap with native gastropods.A stable isotope mixing model was used together with gut content analysis to estimate the diet of T. granifera and native gastropod populations in three different coastal lakes. Population density, available biomass of food and salinity were measured along transects placed over T. granifera patches. An index of isotopic (stable isotopes) dietary overlap (IDO, %) aided in interpreting interactions between gastropods. The diet of T. granifera was variable, including contributions from microphytobenthos, filamentous algae (Cladophora sp.), detritus and sedimentary organic matter. IDO was significant (>60%) between T. granifera and each of the following gastropods: Haminoea natalensis (Krauss, 1848), Bulinus natalensis (Küster, 1841) and Melanoides tuberculata (Müller, 1774). However, food did not appear to be limiting. Salinity influenced gastropod spatial overlap. Tarebia granifera may only displace native gastropods, such as Assiminea cf. ovata (Krauss, 1848), under salinity conditions below 20. Ecosystem-level impacts are also discussed.The generalist diet of T. granifera may certainly contribute to its successful establishment. However, although competition for resources may take place under certain salinity conditions and if food is limiting, there appear to be other mechanisms at work, through which T. granifera displaces native gastropods. Complementary stable isotope and gut content analysis can provide helpful ecological insights, contributing to monitoring efforts and guiding further invasive species research
Correlation of male genital filaments and female spermathecal ducts in New World sand flies of the Lutzomyia intermedia species complex (Diptera: Psychodidae, Phlebotominae)
Seasonality of Lutzomyia fairtigi (Diptera: Psychodidae: Phlebotominae), a species endemic to Eastern Colombia
The nature and extent of evidence on methodologies for monitoring and evaluating marine spatial management measures in the UK and similar coastal waters : a systematic map
Background: Anthropogenic degradation of marine ecosystems is widely accepted as a major social-ecological problem. The growing urgency to manage marine ecosystems more effectively has led to increasing application of spatial management measures (marine protected areas [MPAs], sectoral [e.g. fishery] closures and marine spatial planning [marine plans]). Understanding the methodologies used to evaluate the effectiveness of these measures against social, economic, and ecological outcomes is key for designing effective monitoring and evaluation programmes. Methods: We used a pre-defined and tested search string focusing on intervention and outcome terms to search for relevant studies across four bibliographic databases, Google Scholar, 39 organisational websites, and one specialist data repository. Searches were conducted in English and restricted to the period 2009 to 2019 to align with current UK marine policy contexts. Relevant studies were restricted to UK-relevant coastal countries, as identified by key stakeholders. Search results were screened for relevance against pre-defined eligibility criteria first at title and abstract level, and then at full text. Articles assessed as not relevant at full text were recorded with reasons for exclusion. Two systematic map databases of meta-data and coded data from relevant primary and secondary studies, respectively, were produced. Review findings: Over 19,500 search results were identified, resulting in 391 relevant primary articles, 33 secondary articles and 49 tertiary reviews. Relevant primary articles evaluated spatial management measures across a total of 22 social, economic and ecological outcomes; only 2.8% considered all three disciplines, with most focused exclusively on ecological (67.8%) or social (13.3%) evaluations. Secondary articles predominately focused on ecological evaluations (75.8%). The majority of the primary and secondary evidence base aimed to evaluate the effectiveness of MPAs (85.7% and 90.9% respectively), followed by fisheries closures (12.5%; 3.0%) with only 1.8% of primary, and 6.1% of secondary, articles focused on marine plans or on MPAs and fisheries closures combined. Most evaluations reported within primary articles were conducted for a single site (60.4%) or multiple individual sites (32.5%), with few evaluating networks of sites (6.9%). Secondary articles mostly evaluated multiple individual sites (93.9%). Most (70.3%) primary articles conducted principal evaluations, i.e. basic description of effects; 29.4% explored causation; and 0.3% undertook benefit evaluations. Secondary articles predominately explored causation (66.7%) with the remainder conducting principal evaluations. Australia (27.4%), the USA (18.4%) and the UK (11.3%) were most frequently studied by primary articles, with secondary articles reporting mostly global (66.7%) or European (18.2%) syntheses. Conclusions: The systematic map reveals substantial bodies of evidence relating to methods of evaluating MPAs against ecological outcomes. However, key knowledge gaps include evaluation across social and economic outcomes and of overall merit and/or worth (benefit evaluation), as well as of: marine plans; networks of sites; real-time, temporary or seasonal closures; spatial management within offshore waters, and lagoon or estuary environments. Although the evidence base has grown over the past two decades, information to develop comprehensive evaluation frameworks remains insufficient. Greater understanding on how to evaluate the effectiveness of spatial management measures is required to support improved management of global ocean resources and spaces
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