scholarly journals Experiments on invertebrate predation on cladocerans and its relationships with lake data

2021 ◽  
Author(s):  
Tânia C. Dos Santos Ferreira ◽  
Marlene S. Arcifa
Keyword(s):  
Prey Species ◽  
Laboratory Data ◽  
Fourth Instar ◽  
Experimental Results ◽  
Light Conditions ◽  
Invertebrate Predation ◽  
Water Mite ◽  
Cladoceran Species ◽  
Invertebrate Predators ◽  
The Impact

Until recently, knowledge of the impact of invertebrate predators on cladocerans in the Brazilian Lake Monte Alegre was limited to a few species. In order to assess the effects of predation on other cladoceran species, experiments were carried out with different pair-wise combinations of prey species. The experiments tested predation by fourth instar larvae of the dipteran Chaoborus brasiliensis Theobald on neonates and adults of the cladocerans Daphnia gessneri Herbst, Diaphanosoma birgei Kořínek, and Ceriodaphnia richardi Sars, and predation by the water mite Krendowskia sp. on neonates and adults of C. richardi and D. gessneri. In replicated treatments, the prey was offered alone or in combination with neonates and adults of two species and kept in bottles on a plankton wheel under controlled temperature, photoperiod, and light conditions. Chaoborus larvae preyed on neonates of D. birgei and D. gessneri and on adults of the former species. They preyed preferentially on neonates and adults of D. birgei over neonates and adults of C. richardi. The mite Krendowskia sp. preyed on only one species: neonates and adults of D. gessneri. Data on the distribution and strategies of prey in the lake are discussed in light of the experimental results, in an attempt to establish a link between laboratory data and field conditions.

The Impact of Cash Mobs in the Vote with the Wallet Game: Experimental Results

2016 ◽  
Author(s):  
Leonardo Becchetti ◽  
Maurizio Fiaschetti ◽  
Francesco Salustri
Keyword(s):  
Experimental Results ◽  
The Impact

Glucose Levels and Outcome After Primary Intraventricular Hemorrhage

2019 ◽  
Vol 16 (1) ◽  
pp. 40-46
Author(s):  
Rui Guo ◽  
Ruiqi Chen ◽  
Chao You ◽  
Lu Ma ◽  
Hao Li ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Blood Glucose ◽  
Blood Glucose Level ◽  
Incidence Rate ◽  
Glucose Level ◽  
Intraventricular Hemorrhage ◽  
Laboratory Data ◽  
History Of ◽  
Poor Outcomes ◽  
The Impact

Background and Purpose: Hyperglycemia is reported to be associated with poor outcome in patients with spontaneous Intracerebral Hemorrhage (ICH), but the association between blood glucose level and outcomes in Primary Intraventricular Hemorrhage (PIVH) remains unclear. We sought to identify the parameters associated with admission hyperglycemia and analyze the impact of hyperglycemia on clinical outcome in patients with PIVH. Methods: Patients admitted to Department of Neurosurgery, West China Hospital with PIVH between 2010 and 2016 were retrospectively included in our study. Clinical, radiographic, and laboratory data were collected. Univariate and multivariate logistic regression analyses were used to identify independent predictors of poor outcomes. Results: One hundred and seventy patients were included in the analysis. Mean admission blood glucose level was 7.78±2.73 mmol/L and 10 patients (5.9%) had a history of diabetes mellitus. History of diabetes mellitus (P = 0.01; Odds Ratio [OR], 9.10; 95% Confidence Interval [CI], 1.64 to 50.54) was independent predictor of admission critical hyperglycemia defined at 8.17 mmol/L. Patients with admission critical hyperglycemia poorer outcome at discharge (P < 0.001) and 90 days (P < 0.001). After adjustment, admission blood glucose was significantly associated with discharge (P = 0.01; OR, 1.30; 95% CI, 1.06 to 1.59) and 90-day poor outcomes (P = 0.03; OR, 1.27; 95% CI, 1.03 to 1.58), as well as mortality at 90 days (P = 0.005; OR, 1.41; 95% CI, 1.11 to 1.78). In addition, admission critical hyperglycemia showed significantly increased the incidence rate of pneumonia in PIVH (P = 0.02; OR, 6.04; 95% CI 1.27 to 28.80) even after adjusting for the confounders. Conclusion: Admission blood glucose after PIVH is associated with discharge and 90-day poor outcomes, as well as mortality at 90 days. Admission hyperglycemia significantly increases the incidence rate of pneumonia in PIVH.

Trophic Cascades in Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Indirect Effects ◽  
Prey Species ◽  
Trophic Levels ◽  
Herbaceous Plant ◽  
Direct Effects ◽  
Temperate Grasslands ◽  
Cascading Effect ◽  
Top Predators ◽  
Invertebrate Predators ◽  
Ecology Of Fear

Top predators have effects that can ‘cascade down’ on lower trophic levels. Because of this cascading effect, it matters how many trophic levels are present. Predators are either ‘sit and wait’ or ‘active’. Wolves are top predators in temperate grasslands and can alter species composition of smaller-sized predators, prey, and woody and herbaceous plant species, either through direct effects or indirect effects (‘Ecology of Fear’). In human derived grasslands, invertebrate predators fill a similar ecological role as wolves. Migrating populations of herbivores tend to be more limited by food than non-migratory populations. The phenology and synchrony of births vary among prey species in a way that is consistent with an adaptation to predation. Precocious species have highly synchronous birth dates to satiate predators. Non-precocious species (‘hiders’) have asynchronous births. Results from studies that manipulate both predators and food support the hypothesis that bottom-up and top-down effects interact.

scholarly journals Experimental study of the supercritical CO 2 diffusion coefficient in porous media under reservoir conditions

2019 ◽  
Vol 6 (6) ◽  
pp. 181902 ◽  
Author(s):  
Junchen Lv ◽  
Yuan Chi ◽  
Changzhong Zhao ◽  
Yi Zhang ◽  
Hailin Mu
Keyword(s):  
Porous Media ◽  
Diffusion Coefficient ◽  
Oil Recovery ◽  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Elevated Pressure ◽  
Experimental Results ◽  
Saturated Porous Media ◽  
Reservoir Conditions ◽  
The Impact

Reliable measurement of the CO 2 diffusion coefficient in consolidated oil-saturated porous media is critical for the design and performance of CO 2 -enhanced oil recovery (EOR) and carbon capture and storage (CCS) projects. A thorough experimental investigation of the supercritical CO 2 diffusion in n -decane-saturated Berea cores with permeabilities of 50 and 100 mD was conducted in this study at elevated pressure (10–25 MPa) and temperature (333.15–373.15 K), which simulated actual reservoir conditions. The supercritical CO 2 diffusion coefficients in the Berea cores were calculated by a model appropriate for diffusion in porous media based on Fick's Law. The results show that the supercritical CO 2 diffusion coefficient increases as the pressure, temperature and permeability increase. The supercritical CO 2 diffusion coefficient first increases slowly at 10 MPa and then grows significantly with increasing pressure. The impact of the pressure decreases at elevated temperature. The effect of permeability remains steady despite the temperature change during the experiments. The effect of gas state and porous media on the supercritical CO 2 diffusion coefficient was further discussed by comparing the results of this study with previous study. Based on the experimental results, an empirical correlation for supercritical CO 2 diffusion coefficient in n -decane-saturated porous media was developed. The experimental results contribute to the study of supercritical CO 2 diffusion in compact porous media.

Intra-aortic balloon pump as a bridge therapy to heart transplant in refractory heart failure

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
G.A.B Boros ◽  
V.S.C Bellini ◽  
D Fatori ◽  
C Bernoche ◽  
M.F Macatrao-Costa ◽  
...  
Keyword(s):  
Heart Failure ◽  
Intensive Care ◽  
Heart Transplant ◽  
Insertion Site ◽  
Laboratory Data ◽  
Central Venous Oxygen Saturation ◽  
Single Center ◽  
Intra Aortic Balloon Pump ◽  
The Impact ◽  
Bridge Therapy

Abstract Background The role of intra-aortic balloon pump (IABP) in advanced heart failure (HF) treatment is still under debate. Some heart transplant (HTx) candidates on the waiting list require mechanical support, and IABP may be the simple and most available device. Purpose Describe the impact of IABP treatment in advanced HF patients who underwent HTx. Methods We retrospectively analysis patients who underwent HTx from a single center intensive care unit (ICU), between 2009 and 2018, to evaluate the use of IABP as bridge therapy. Selection included decompensated chronic HF patients that required intensive care with optimized intravenous drugs before IABP placement. Exclusion criteria were acute myocardial infarction or cardiac surgery 90 days prior to admission, and implant of ventricular assist device before HTx. Results We included 134 HF patients with IABP therapy before HTx. Insertion site was exclusively femoral. Mean time of IABP onset to HTx were 26±21 days, and hospital admission to HTx 65±45 days. The main cardiomyopathy etiology was Chagas Disease (46%) and mean LVEF was 23±6% (TABLE 1). Clinical and laboratory data were compared before and 96 hours after IABP therapy. Mean central venous oxygen saturation (SvO2) increased from 49.7±14.6% to 67.4±11.3% (p&lt;0.001), creatinine decreased from 1.77±0.9 mg/dL to 1.40±0.6 mg/dL (p&lt;0.001), and urine output increased from 1552±886 mL/24h to 2189±1029 mL/24h (p&lt;0.001). These differences were sustained or improved until the day before HTx (FIGURE 1). After 96 hours dobutamine was maintained in 98% of patients, nitroprusside increased from 56% to 67%, milrinone decreased from 26% to 20%, and norepinephrine decreased from 18% to 3%. Significant IABP complications were few (5.2%; n=7: 3 infections, 2 major bleeding, 2 arterial injury). Conclusion In this single center ICU sample, IABP improved hemodynamic status and renal function in refractory HF patients waiting for HTx. IABP can be a reasonable, available and effective bridging therapy. Figure 1 Funding Acknowledgement Type of funding source: None

scholarly journals Three doors anomaly, “should I stay, or should I go”: an artefactual field experiment

2021 ◽  
Author(s):  
Andrea Morone ◽  
Rocco Caferra ◽  
Alessia Casamassima ◽  
Alessandro Cascavilla ◽  
Paola Tiranzoni
Keyword(s):  
Field Experiment ◽  
Experimental Evidence ◽  
Bayesian Updating ◽  
Anomalous Behavior ◽  
Status Quo ◽  
Experimental Results ◽  
Illusion Of Control ◽  
Optimal Decision ◽  
Status Quo Bias ◽  
The Impact

AbstractThis work aims to identify and quantify the biases behind the anomalous behavior of people when they deal with the Three Doors dilemma, which is a really simple but counterintuitive game. Carrying out an artefactual field experiment and proposing eight different treatments to isolate the anomalies, we provide new interesting experimental evidence on the reasons why subjects fail to take the optimal decision. According to the experimental results, we are able to quantify the size and the impact of three main biases that explain the anomalous behavior of participants: Bayesian updating, illusion of control and status quo bias.

Devanagari Text Detection From Natural Scene Images

2020 ◽  
Vol 10 (3) ◽  
pp. 44-59
Author(s):  
Sankirti Sandeep Shiravale ◽  
R. Jayadevan ◽  
Sanjeev S. Sannakki
Keyword(s):  
Edge Detection ◽  
Image Understanding ◽  
Text Detection ◽  
Experimental Results ◽  
Combined Approach ◽  
Natural Scene ◽  
Light Conditions ◽  
The Individual ◽  
Natural Scene Images ◽  
Better Than

Text present in a camera captured scene images is semantically rich and can be used for image understanding. Automatic detection, extraction, and recognition of text are crucial in image understanding applications. Text detection from natural scene images is a tedious task due to complex background, uneven light conditions, multi-coloured and multi-sized font. Two techniques, namely ‘edge detection' and ‘colour-based clustering', are combined in this paper to detect text in scene images. Region properties are used for elimination of falsely generated annotations. A dataset of 1250 images is created and used for experimentation. Experimental results show that the combined approach performs better than the individual approaches.

Changes in the crustacean communities of Lakes Michigan, Huron, and Erie following the invasion of the predatory cladoceran Bythotrephes longimanus

2004 ◽  
Vol 61 (11) ◽  
pp. 2111-2125 ◽  
Author(s):  
Richard P Barbiero ◽  
Marc L Tuchman
Keyword(s):  
Zooplankton Community ◽  
Crustacean Zooplankton ◽  
Bythotrephes Longimanus ◽  
Zooplankton Community Structure ◽  
Cladoceran Species ◽  
Invertebrate Predators ◽  
Predatory Cladoceran ◽  
Leptodora Kindti ◽  
Escape Responses ◽  
Zooplankton Communities

The crustacean zooplankton communities in Lakes Michigan and Huron and the central and eastern basins of Lake Erie have shown substantial, persistent changes since the invasion of the predatory cladoceran Bythotrephes in the mid-1980s. A number of cladoceran species have declined dramatically since the invasion, including Eubosmina coregoni, Holopedium gibberum, Daphnia retrocurva, Daphnia pulicaria, and Leptodora kindti, and overall species richness has decreased as a result. Copepods have been relatively unaffected, with the notable exception of Meso cyclops edax, which has virtually disappeared from the lakes. These species shifts have for the most part been consistent and equally pronounced across all three lakes. Responses of crustacean species to the Bythotrephes invasion do not appear to be solely a consequence of size, and it is likely that other factors, e.g., morphology, vertical distribution, or escape responses, are important determinants of vulnerability to predation. Our results indicate that invertebrate predators in general, and invasive ones in particular, can have pronounced, lasting effects on zooplankton community structure.

The impact of leaf shape on the feeding preference of insect herbivores: experimental and field studies with Capsella and Phyllotreta

1996 ◽  
Vol 351 (1348) ◽  
pp. 1671-1677 ◽  
Keyword(s):  
Leaf Shape ◽  
Laboratory Data ◽  
Leaf Size ◽  
Field Studies ◽  
Feeding Preference ◽  
Insect Herbivores ◽  
Flea Beetles ◽  
Shape Effects ◽  
Leaf Size And Shape ◽  
The Impact

Leaves display an enormous array of sizes and shapes. Although these attributes appear to have evolved primarily in response to abiotic conditions in the plant’s habitat, the importance of insect herbivores as additional selective agents is still poorly understood. A necessary requirem ent for leaf size and shape to evolve in response to attack by insects is that insects must respond to and/or be affected by, leaf morphology. We tested leaf-shape preferences in adult flea beetles ( Phyllotreta spp.) feeding on the highly variable rosette leaves of Capsella bursa-pastoris . Contrary to theoretical expectation (Brown & Lawton 1991), leaves with deeply lobed margins were more intensely damaged, both in field-collected and experimental plants. In two ancillary experiments with Capsella , we found that Spodoptera caterpillars showed no preferences for leaf shape, but that adult vine weevils ( Otiorhynchus sulcatus ) did, preferring (as predicted), undivided over divided leaves. We conclude that Brown & Law ton’s (1991) hypothesis is at best weakly supported by laboratory data for vine weevils, refuted by laboratory data for Spodoptera , and consistently refuted by both laboratory and field data for flea beetles. Although the experiment tried to reduce confounding variables to a minimum, interpretation was complicated by correlations between leaf shape and other developmental parameters of the plants, and highlights the difficulty of disentangling leaf-shape effects from other confounding factors.

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