The consequences of reservoir host eradication on disease epidemiology in animal communities.

Non-native species have often been linked with introduction of novel pathogens that spill over into native communities, and the amplification of the prevalence of native parasites. In the case of introduced generalist pathogens, their disease epidemiology in the extant communities remains poorly understood. Here, Sphaerothecum destruens, a generalist fungal-like fish pathogen with bi-modal transmission (direct and environmental) was used to characterise the biological drivers responsible for disease emergence in temperate fish communities. A range of biotic factors relating to both the pathogen and the surrounding host communities were used in a novel susceptible-exposed-infectious-recovered (SEIR) model to test how these factors affected disease epidemiology. These included: (i) pathogen prevalence in an introduced reservoir host (Pseudorasbora parva); (ii) the impact of reservoir host eradication and its timing and (iii) the density of potential hosts in surrounding communities and their connectedness. These were modelled across 23 combinations and indicated that the spill-over of pathogen propagules via environmental transmission resulted in rapid establishment in adjacent fish communities (<1 year). Although disease dynamics were initially driven by environmental transmission in these communities, once sufficient numbers of native hosts were infected, the disease dynamics were driven by intra-species transmission. Subsequent eradication of the introduced host, irrespective of its timing (after one, two or three years), had limited impact on the long-term disease dynamics among local fish communities. These outputs reinforced the importance of rapid detection and eradication of non-native species, in particular when such species are identified as healthy reservoirs of a generalist pathogen

Parasites of non-native freshwater fishes introduced into england and wales suggest enemy release and parasite acquisition

When non-native species are introduced into a new range, their parasites can also be introduced, with these potentially spilling-over into native hosts. However, in general, evidence suggests that a high proportion of their native parasites are lost during introduction and infections by some new parasites from the native range might occur, potentially resulting in parasite spill-back to native species. These processes were investigated here using parasite surveys and literature review on seven non-native freshwater fishes introduced into England and Wales. Comparison of the mean numbers of parasite species and genera per population for each fish species England andWaleswith their native ranges revealed\9 % of the native parasite fauna were present in their populations in England and Wales. There was no evidence suggesting these introduced parasites had spilled over into sympatric native fishes. The non-native fishes did acquire parasites following their introduction, providing potential for parasite spill-back to sympatric fishes, and resulted in non-significant differences in overall mean numbers of parasites per populations between the two ranges. Through this acquisition, the non-native fishes also had mean numbers of parasite species and genera per population that were not significantly different to sympatric native fishes. Thus, the non-native fishes in England and Wales showed evidence of enemy release, acquired new parasites following introduction providing potential for spill-back, but showed no evidence of parasite spill-over

Rhodophyta de ambientes lóticos de Unidades de Conservação da região Sul do Brasil

Species of Rhodophyta from 10 Conservation Units from the south region of Brazil were surveyed. The samplings were carried out in 105 stream reaches, consisting of 10 m length transects. The floristic survey involved 80 populations, representing three genera, Batrachospermum, Kumanoa and Hildenbrandia plus the 'Chantransia' stages. Batrachospermum was represented by five species (B. arcuatum Kylin, B. atrum (Hudson) Harvey, B. helminthosum Bory, B. keratophytum Bory and B. puiggarianum Grunow in Wittrock & Nordstedt). The genus Kumanoa was represented by K. abilii (Reis) Necchi Junior & Vis and K. ambigua (Montagne) Entwisle et al., while Hildenbrandia only by H. angolensis W.West & G.S.West. Our results confirm Batachospermum as the best represented genus, in terms of species number, among freshwater Rhdophyta. B. arcuatum was a new record for the south region of Brazil, thus extending its austral distribution range.Espécies de Rhodophyta de 10 Unidades de Conservação da região Sul do Brasil foram investigadas. As amostragens foram conduzidas em 105 segmentos de riachos consistindo em transeções de 10 m de comprimento. O levantamento florístico resultou em 80 populações representando três gêneros, Batrachospermum, Kumanoa e Hildenbrandia, além do estágios ‘Chantransia’. Batrachospermum foi representado por cinco espécies (B. arcuatum Kylin, B. atrum (Hudson) Harvey, B. helminthosum Bory, B. keratophytum Bory, B. puiggarianum Grunow in Wittrock & Nordstedt). O gênero Kumanoa foi representado por K. abilii (Reis) Necchi Júnior & Vis e K. ambigua (Montagne) Entwisle et al., enquanto Hildenbrandia exclusivamente por H. angolensis W. West & G.S. West. Nossos resultados confirmam Batachospermum como o gênero melhor representado, em termos de número de espécies, entre as Rhdophyta de água doce. Batrachospermum arcuatum foi registrado pela primeira vez na região Sul do Brasil, ampliando assim, o limite austral de sua distribuição.Univ Estadual Paulista UNESP, FCL, BR-19806900 Assis, SP, BrazilUniv Fed Integracao Latino Amer UNILA, Foz do Iguacu, PR, BrazilUniv Estadual Paulista UNESP, Dept Zool & Bot, BR-15054000 Sao Jose do Rio Preto, SP, BrazilUniv Estadual Paulista UNESP, FCL, BR-19806900 Assis, SP, BrazilUniv Estadual Paulista UNESP, Dept Zool & Bot, BR-15054000 Sao Jose do Rio Preto, SP, Brazi

Flora de comunidades de macroalgas lóticas de fragmentos florestais remanescentes da região noroeste do Estado de São Paulo, Brasil

Foram amostrados 17 riachos, em 12 fragmentos durante a estação seca (junho a agosto de 2007 e de 2008). Foram identificadas 16 espécies de macroalgas, pertencentes a 14 gêneros. Cyanophyta e Chlorophyta foram os grupos mais representativos (44 e 38%, respectivamente), seguidos por Rhodophyta (12%) e Heterokontophyta (6%). O número global de espécies foi baixo, fato atribuído à predominância de substrato areno-argiloso (65%) e de trechos sombreados (53%). A maioria das espécies (69%) ocorreu exclusivamente em um único riacho, padrão frequentemente observado para macroalgas lóticas. Vaucheria pseudogeminata foi reportada pela primeira vez para o Brasil e Trichocoleus sociatus para a região noroeste do Estado de São Paulo. Comparando a flora de macroalgas encontrada com aquelas de outras regiões/biomas do Estado de São Paulo, notou-se maior semelhança com Floresta Tropical (56% espécies em comum), conforme esperado, por ser o bioma mais próximo e composto também por Floresta Estacional Semidecidual.Seventeen streams in 12 forest fragments were sampled during the dry season (June to August of 2007 and of 2008). Sixteen species belonging to 14 genera were found. Cyanophyta and Chlorophyta were the best represented algal division (44 and 38%, respectively), followed by Rhodophyta (12%) and Heterokontophyta (6%). Global species number was low, probably due to predominance of sand-clay substrates (65%) and of shaded stream segments (53%). Most species (69%) occurred in only one stream, a pattern often observed in lotic macroalgal communities. Vaucheria pseudogeminata was reported for the first time for Brazil, whereas Trichocoleus sociatus for this region. Comparing these macroalgal flora with those from other biomes of São Paulo State, the highest similarity was with Tropical Forest (56% in common), as expected because it is the nearest biome and also constituted by Semideciduous Seasonal Forest.Universidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências, Letras e Ciências Exatas Departamento de Zoologia e BotânicaUniversidade Estadual Paulista Júlio de Mesquita Filho Instituto de Biociências, Letras e Ciências Exatas Departamento de Zoologia e Botânic

Benthic algal response to N and P enrichment along a pH gradient

Nutrient enrichment and its effect on benthic algal growth, community composition, and average cell size was assessed across two sites of differing pH within a single habitat. Nutrients were added using in situ substrata, which released either N, P, or no additional nutrients (controls) at each site for 21 days. Upon collection, chlorophyll and biovolume standing stocks of the attached algal microflora were measured. Chlorophyll concentration was different among all treatments, accumulating greatest on P, followed by N, and the least on C substrata (P < 0.001) and was highest at site-2 (P < 0.001), while total algal biovolume was highest on P compared to both N and C substrata (P < 0.05) and did not vary between sites. Increased growth on P substrata was due to the enhanced biovolume of filamentous green algae, although the affected taxa varied between sites. Biovolume to cell density ratios (as a measure of average cell size) were highest on P substrata over both N-enriched and control substrata (P < 0.05) and this pattern was similar between sites. Progression towards a community composed of larger cells following P enrichment observed along this pH gradient, seems to be related to the dominance of larger celled filamentous green algae. Thus, nutrients exhibited greater control on benthic algal growth than did changes in hydrogen ion concentration.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42877/1/10750_2004_Article_BF00007599.pd

Carbon dioxide fluxes increase from day to night across European streams

Globally, inland waters emit over 2 Pg of carbon per year as carbon dioxide, of which the majority originates from streams and rivers. Despite the global significance of fluvial carbon dioxide emissions, little is known about their diel dynamics. Here we present a large-scale assessment of day- and night-time carbon dioxide fluxes at the water-air interface across 34 European streams. We directly measured fluxes four times between October 2016 and July 2017 using drifting chambers. Median fluxes are 1.4 and 2.1 mmol m−2 h−1 at midday and midnight, respectively, with night fluxes exceeding those during the day by 39%. We attribute diel carbon dioxide flux variability mainly to changes in the water partial pressure of carbon dioxide. However, no consistent drivers could be identified across sites. Our findings highlight widespread day-night changes in fluvial carbon dioxide fluxes and suggest that the time of day greatly influences measured carbon dioxide fluxes across European streams

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Survivorship of the KUDO total elbow prosthesis--comparative study of cemented and uncemented ulnar components: 89 cases followed for an average of 6 years.

Contains fulltext : 53014.pdf (publisher's version ) (Open Access)BACKGROUND: The Kudo total elbow prosthesis (TEP) is a well-established implant with good mid-term results. The ulnar component can be placed with or without cement, and the humeral component is normally placed without cement. METHODS: 89 Kudo type-5 total elbow prostheses were evaluated after a mean follow-up of 6 (1.7-11) years. The indication for joint replacement was rheumatoid arthritis in all cases. 49 prostheses were placed without cement. In 40 cases, the ulnar component was cemented and the humeral component was uncemented. RESULTS: In the uncemented group, 7 revisions had taken place. 3 of these ulnar components were shortstemmed and 4 were long-stemmed. No revisions had been performed in the hybrid group. In the uncemented group another 7 patients showed progressive radiolucencies, while 3 patients in the hybrid group showed progressive radiolucencies. INTERPRETATION: In this group of RA patients, the survivorship of the cemented ulnar component was better than that of the uncemented ulnar component

Interglacial History of a Palaeo-lake and Regional Environment: A Multi-proxy Study of a Permafrost Deposit from Bolshoy Lyakhovsky Island, Arctic Siberia

Chironomid, pollen, and rhizopod records from a permafrost sequence at the Bolshoy Lyakhovsky Island (New Siberian Archipelago) document the evolution of a thermokarst palaeo-lake and environmental conditions in the region during the Last Interglacial (MIS 5e, ca. 130120 ka). Open Poaceae and Artemisia associations dominated vegetation at the beginning of the interglacial period, ca. 130 ka. Rare shrub thickets (Salix, Betula nana, Alnus fruticosa) grew in more protected and wetter places as well. Saalian ice wedges started to melt during this time, resulting in the formation of an initial thermokarst water body. The high percentage of semi-aquatic chironomids suggests that a peatland-pool palaeo-biotope existed at the site, when initial water body started to form. A distinct decrease in semi-aquatic chironomid taxa and an increase in lacustrine ones point to a gradual pooling of water in basin, which could in turn create thaw a permanent pond during the subsequent period. The highest relative abundance of Chironomus and Procladius reflects an existence of unfrozen water remaining under the ice throughout the ice-covered period during the later stage of palaeo-lake development. Chironomid record points to three successive stages during the water body evolution: (1) a peatland pool; (2) a pond (i.e., less deep than the maximum ice-cover thickness); and (3) a shallow lake (i.e., more deep than the maximum ice-cover thickness). The evolutionary trend of palaeo-lake points to intensive thermokarst processes occurring in the region during the Last Interglacial. Shrub tundra communities with Alnus fruticosa, Betula nana dominated the vegetation during the interglacial optimum that is evidenced by pollen record. The climate was relatively moist and warm. The results of this study suggest that quantitative chironomid-based temperature reconstructions from the Arctic thermokarst ponds/lakes may be problematic owing to other key environmental factors, such as prolonged periods of winter anoxia and local hydrological/geomorphological processes, controlling the chironomid assemblage