161 research outputs found

    Recruitment and growth of Megabalanus azoricus (Pilsbry, 1916) on artificial substrates: first steps towards commercial culture in the Azores

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    This paper reports the results of preliminary research evaluating the potential of farming Megabalanus azoricus. From March 2006 to September 2006, artificial substrates were immersed bi-monthly in a shallow water bank located in the channel separating the islands of Faial and Pico, Azores. They were monitored monthly for a period of 12 months by scuba-diving. M. azoricus rapidly colonised the immersed substrates, establishing itself as the dominant organism. Even though recruitment was observed year round, there was a peak in recruitment between June and October. The substrate immersed for the longest period (15 months) presented final densities of 1109 ind. m-2, from which 20.2% were of edible size. Growth was monitored for 18 isolated barnacles for 8 months. Growth rate proved to be high (base diameter; 0.08 ± 0.02 mm day-1; mean ± SD), with individuals reaching diameters of 21.35 ± 6.2 mm after 8 months. Considering this growth rate, it was estimated that after a further 9 months, over 80% of the total densities (on the oldest substrate ) would be harvestable, thus suggesting a production cycle of 17 to 24 months. Although much further research is needed, the species presents all characteristics of a potential candidate to initiate the aquaculture industry in the Azores

    Disease burden due to gastrointestinal infections among people living along the major wastewater system in Hanoi, Vietnam

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    Background : Despite recent improvements of wastewater treatment capacities in urban areas of Hanoi, Vietnam, microbial pollution is still considerable. There is a paucity of burden estimates due to gastrointestinal infection in people living along the wastewater system, and among people who are in direct contact with the wastewater, such as farmers using wastewater in agriculture and aquaculture. Methods : A quantitative microbial risk assessment (QMRA) was pursued focussing on four population groups characterised by different levels of exposure to wastewater: (i) workers maintaining the wastewater conveyance and treatment systems; (ii) urban farmers using wastewater from To Lich River; (iii) community members in urban areas exposed to flooding events in the districts of Hoang Mai and Thanh Tri; and (iv) peri-urban farmers in Thanh Tri district, where Red River water is used for agriculture and aquaculture. The QMRA was developed on the basis of measured concentration of Escherichia coli and Salmonella spp. and Ascaris spp. eggs in water samples. Published ratios between measured organisms and pathogenic strains of norovirus, rotavirus, Campylobacter spp., pathogenic E. coli, pathogenic Salmonella spp., Cryptosporidium spp. and Ascaris lumbricoides were employed to estimate annual risk of gastrointestinal infection and disease burden. Results : The QMRA estimated a disease burden of 0.011 disability-adjusted life years (DALYs) per person per year in urban farmers, 0.006 DALYs for sanitation workers, 0.0005 DALYs for urban communities at risk of flooding events and 0.0004 DALYs for peri-urban farmers. Urban farmers had considerably higher incidence estimates for gastrointestinal disease episodes per year (2.0) compared to the other exposure groups (≀1.0). Conclusions : Urban farmers using wastewater from To Lich River have a high gastrointestinal disease burden, which is about 100 times larger than the health-based targets for wastewater use set by the World Health Organization. These findings are of direct public health relevance and call for upgrading Hanoi's wastewater system to reduce microbial contamination. Finally, this study presents a first example on how to link QMRA to a sanitation safety planning (SSP) approach in an Asian context and its findings are interesting in the frame of Sustainable Development Goal (SDGs) #6

    Predicting the Response to Intravenous Immunoglobulins in an Animal Model of Chronic Neuritis

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    Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a disabling autoimmune disorder of the peripheral nervous system (PNS). Intravenous immunoglobulins (IVIg) are effective in CIDP, but the treatment response varies greatly between individual patients. Understanding this interindividual variability and predicting the response to IVIg constitute major clinical challenges in CIDP. We previously established intercellular adhesion molecule (ICAM)-1 deficient non-obese diabetic (NOD) mice as a novel animal model of CIDP. Here, we demonstrate that similar to human CIDP patients, ICAM-1 deficient NOD mice respond to IVIg treatment by clinical and histological measures. Nerve magnetic resonance imaging and histology demonstrated that IVIg ameliorates abnormalities preferentially in distal parts of the sciatic nerve branches. The IVIg treatment response also featured great heterogeneity allowing us to identify IVIg responders and non- responders. An increased production of interleukin (IL)-17 positively predicted IVIg treatment responses. In human sural nerve biopsy sections, high numbers of IL-17 producing cells were associated with younger age and shorter disease duration. Thus, our novel animal model can be utilized to identify prognostic markers of treatment responses in chronic inflammatory neuropathies and we identify IL-17 production as one potential such prognostic marker

    Stenosis Length and Degree Interact With the Risk of Cerebrovascular Events Related to Internal Carotid Artery Stenosis

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    Background and Purpose: Internal carotid artery stenosis (ICAS)≄70% is a leading cause of ischemic cerebrovascular events (ICVEs). However, a considerable percentage of stroke survivors with symptomatic ICAS (sICAS) have <70% stenosis with a vulnerable plaque. Whether the length of ICAS is associated with high risk of ICVEs is poorly investigated. Our main aim was to investigate the relation between the length of ICAS and the development of ICVEs.Methods: In a retrospective cross-sectional study, we identified 95 arteries with sICAS and another 64 with asymptomatic internal carotid artery stenosis (aICAS) among 121 patients with ICVEs. The degree and length of ICAS as well as plaque echolucency were assessed on ultrasound scans.Results: A statistically significant inverse correlation between the ultrasound-measured length and degree of ICAS was detected for sICAS≄70% (Spearman correlation coefficient ρ = –0.57, p < 0.001, n = 51) but neither for sICAS<70% (ρ = 0.15, p = 0.45, n = 27) nor for aICAS (ρ = 0.07, p = 0.64, n = 54). The median (IQR) length for sICAS<70% and ≄70% was 17 (15–20) and 15 (12–19) mm (p = 0.06), respectively, while that for sICAS<90% and sICAS 90% was 18 (15–21) and 13 (10–16) mm, respectively (p < 0.001). Among patients with ICAS <70%, a cut-off length of ≄16 mm was found for sICAS rather than aICAS with a sensitivity and specificity of 74.1% and 51.1%, respectively. Irrespective of the stenotic degree, plaques of the sICAS compared to aICAS were significantly more often echolucent (43.2 vs. 24.6%, p = 0.02).Conclusion: We found a statistically insignificant tendency for the ultrasound-measured length of sICAS<70% to be longer than that of sICAS≄70%. Moreover, the ultrasound-measured length of sICAS<90% was significantly longer than that of sICAS 90%. Among patients with sICAS≄70%, the degree and length of stenosis were inversely correlated. Larger studies are needed before a clinical implication can be drawn from these results

    Combined Perfusion and Permeability Imaging Reveals Different Pathophysiologic Tissue Responses After Successful Thrombectomy.

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    Despite successful recanalization of large-vessel occlusions in acute ischemic stroke, individual patients profit to a varying degree. Dynamic susceptibility-weighted perfusion and dynamic T1-weighted contrast-enhanced blood-brain barrier permeability imaging may help to determine secondary stroke injury and predict clinical outcome. We prospectively performed perfusion and permeability imaging in 38 patients within 24 h after successful mechanical thrombectomy of an occlusion of the middle cerebral artery M1 segment. Perfusion alterations were evaluated on cerebral blood flow maps, blood-brain barrier disruption (BBBD) visually and quantitatively on ktrans maps and hemorrhagic transformation on susceptibility-weighted images. Visual BBBD within the DWI lesion corresponded to a median ktrans elevation (IQR) of 0.77 (0.41-1.4) min-1 and was found in all 7 cases of hypoperfusion (100%), in 10 of 16 cases of hyperperfusion (63%), and in only three of 13 cases with unaffected perfusion (23%). BBBD was significantly associated with hemorrhagic transformation (p < 0.001). While BBBD alone was not a predictor of clinical outcome at 3 months (positive predictive value (PPV) = 0.8 [0.56-0.94]), hypoperfusion occurred more often in patients with unfavorable clinical outcome (PPV = 0.43 [0.10-0.82]) compared to hyperperfusion (PPV = 0.93 [0.68-1.0]) or unaffected perfusion (PPV = 1.0 [0.75-1.0]). We show that combined perfusion and permeability imaging reveals distinct infarct signatures after recanalization, indicating the severity of prior ischemic damage. It assists in predicting clinical outcome and may identify patients at risk of stroke progression

    Profiles of cognitive impairment in chronic heart failure—A cluster analytic approach

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    BackgroundCognitive impairment is a major comorbidity in patients with chronic heart failure (HF) with a wide range of phenotypes. In this study, we aimed to identify and compare different clusters of cognitive deficits.MethodsThe prospective cohort study “Cognition.Matters-HF” recruited 147 chronic HF patients (aged 64.5 ± 10.8 years; 16.2% female) of any etiology. All patients underwent extensive neuropsychological testing. We performed a hierarchical cluster analysis of the cognitive domains, such as intensity of attention, visual/verbal memory, and executive function. Generated clusters were compared exploratively with respect to the results of cardiological, neurological, and neuroradiological examinations without correction for multiple testing.ResultsDendrogram and the scree plot suggested three distinct cognitive profiles: In the first cluster, 42 patients (28.6%) performed without any deficits in all domains. Exclusively, the intensity of attention deficits was seen in the second cluster, including 55 patients (37.4%). A third cluster with 50 patients (34.0%) was characterized by deficits in all cognitive domains. Age (p = 0.163) and typical clinical markers of chronic HF, such as ejection fraction (p = 0.222), 6-min walking test distance (p = 0.138), NT-proBNP (p = 0.364), and New York Heart Association class (p = 0.868) did not differ between clusters. However, we observed that women (p = 0.012) and patients with previous cardiac valve surgery (p = 0.005) prevailed in the “global deficits” cluster and the “no deficits” group had a lower prevalence of underlying arterial hypertension (p = 0.029). Total brain volume (p = 0.017) was smaller in the global deficit cluster, and serum levels of glial fibrillary acidic protein were increased (p = 0.048).ConclusionApart from cognitively healthy and globally impaired HF patients, we identified a group with deficits only in the intensity of attention. Women and patients with previous cardiac valve surgery are at risk for global cognitive impairment when suffering HF and could benefit from special multimodal treatment addressing the psychosocial condition

    Transient bio-inspired gliders with embodied humidity responsive actuators for environmental sensing

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    Collecting temporal and spatial high-resolution environmental data can guide studies in environmental sciences to gain insights in ecological processes. The utilization of automated robotic systems to collect these types of data can maximize accuracy, resilience, and deployment rate. Furthermore, it reduces the risk to researchers deploying sensors in inaccessible environments and can significantly increase the cost-effectiveness of such studies. The introduction of transient robotic systems featuring embodied environmental sensors pushes towards building a digital ecology, while introducing only minimal disturbance to the environment. Transient robots made from fully biodegradable and non-fossil based materials, do not develop into hazardous e-waste at the end of their lifetime and can thus enable a broader adoption for environmental sensing in the real world. In this work, our approach towards the design of transient robots includes the integration of humidity-responsive materials in a glider, which is inspired by the Alsomitra macrocarpa seed. The design space of these gliders is explored and their behavior studied numerically, which allows us to make predictions on their flight characteristics. Results are validated against experiments, which show two different gliding behaviors, that can help improve the spread of the sensors. By tailoring the Cellulose-Gelatin composition of the humidity actuator, self-folding systems for selective rainwater exposure can be designed. The pH sensing layer, protected by the actuator, provides visual feedback on the pH of the rainwater. The presented methods can guide further concepts developing transient aerial robotic systems for sustainable, environmental monitoring
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