190 research outputs found
Effects of Aflatoxin on Some Haematological Parameters and Protective Effectiveness of Esterified Glucomannan in Merino Rams
The objective of the present study was to evaluate the toxic effects of aflatoxin on some hematological parameters and to determine the preventive effectiveness of added glucomannan. In the study, 32 Merino rams were used, and the rams were separated equally to four groups as control (C), glucomannan (G), glucomannanâ+âaflatoxin (AG), and aflatoxin (A). Erythrocyte, leukocyte count, hemoglobin, and hematocrit levels were decreased in A group compared with the other groups, and there was a reduction in similar parameters in AG group compared to control values. On the other hand, these parameters were tended to increase in AG group compared to A group values. Aflatoxicosis caused the lymphocytopenia and monocytopenia but increased percentage of neutrophil counts. In conclusion, the results determined in the study might be important to demonstrate the effects of aflatoxicosis and glucomannan on some haematological parameters before the clinical symptoms appear
Effects of protein deficiency on testosterone levels, semen quality and testicular histology in the developing male rat
The aim of the study was to evaluate the effects of protein deficiency on plasma testosterone levels, epididymal sperm characteristics and testicular histology in the developing male rat. Twenty four Wistar albino rats were used in the study and were fed with a diet variously containing 3 %, 10 % and 20 % protein. Plasma testosterone levels were significantly lower in rats fed 3 % protein when compared to rats fed 10 % and 20 % protein (P<0.05). Testicular weight in protein deficient rats (rats fed 3 % and 10 % protein) was significantly lower than that of a control group (20 % protein) (P<0.05). No sperm was present in the epididymal duct lumen, but germ cells were observed in some duct lumens in rats fed 3 % protein. Epididymal weight decreased significantly in rats fed 3 % protein compared to rats fed 10 % and 20 % protein (P<0.05). The results of this study clearly show that protein deficiency in developing male rats adversely affects gonadal endocrine function, testicular histology and spermatogenesis
Utjecaj oligosaharida hitozana na odreÄene hematoloĆĄke pokazatelje u ĆĄtakora izloĆŸenih kadmiju
The aim of the study was to investigate the effects of chitosan oligosaccharide (COS) on some hematological
parameters, and define the percentage of alpha-naphthyl acetate esterase (ANAE) positive lymphocytes in rats that had
been exposed to cadmium (Cd). Thirty-two (n = 32) male Wistar albino rats were randomly divided into four groups
as the control (C), chitosan oligosaccharide (COS), cadmium (Cd), and Cd + COS (CdCOS) groups. Blood samples
were collected to assess erythrocytes (RBC), leukocytes (WBC), hemoglobin levels (HGB), hematocrit values (HCT),
mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), mean corpuscular
volume (MCV), platelets (PLT), and alpha-naphthyl acetate esterase (ANAE) positive lymphocytes. The number
of WBCs significantly increased in the Cd group compared to the C, CdCOS, and COS groups (P<0.05). Although
the lymphocyte count decreased significantly in the Cd group (P<0.05), it was ameliorated by COS treatment in
the CdCOS group compared to the Cd group (P<0.05). Also, the percentage of peripheral blood ANAE positive
lymphocytes decreased significantly in the CdCOS and Cd groups (P<0.05). COS exhibits a partially protective effect
on some hematological characteristics, apart from the percentage of ANAE positive lymphocyte in cases of chronic
Cd exposure.Cilj ovog rada bio je istraĆŸiti uÄinak oligosaharida hitozana (COS) na odreÄene hematoloĆĄke pokazatelje odnosno
postotak limfocita pozitivnih na alfa-naftil-acetat-esterazu (ANAE) u ĆĄtakora izloĆŸenih kadmiju (Cd). MuĆŸjaci (n = 32)
pasmine Wistar albino, sluÄajnim odabirom podijeljeni su u Äetiri skupine: kontrolnu (C), skupinu s oligosaharidom
hitozanom (COS), skupinu s kadmijem (Cd) i skupinu s kadmijem i oligosaharidom hitozanom (CdCOS). Prikupljeni
su uzorci krvi kako bi se odredili eritrociti (RBC), leukociti (WBC), hemoglobin (HGB), hematokrit (HCT), prosjeÄni
hemoglobin u eritrocitima (MCH) i njegova koncentracija (MCHC), prosjeÄan obujam eritrocita (MCV), trombociti
(PLT), te limfociti pozitivni na alfa-naftil-acetat-esterazu (ANAE). Broj leukocita znakovito je porastao u skupini
Cd u usporedbi s kontrolnom skupinom te skupinama C, CdCOS, i COS (P < 0,05). Iako je broj limfocita znakovito
smanjen u skupini Cd (P < 0,05), to je ublaĆŸeno primjenom COS-a u skupini CdCOS u usporedbi sa skupinom Cd (P <
0,05). TakoÄer, postotak limfocita iz periferne krvi pozitivnih na ANAE znakovito je smanjen u skupinama CdCOS i
Cd (P < 0,05). COS je, u sluÄaju kroniÄne izloĆŸenosti ĆĄtakora kadmiju, pokazao djelomice zaĆĄtitni uÄinak na odreÄene
hematoloĆĄke znaÄajke, osim na postotak limfocita pozitivnih na ANAE
Quality improvement in ammonium nitrate production using Six Sigma methodology
Six sigma has been used in different industries to reach operational excellence. However, in the chemical industry, the application of this methodology is limited. This research presents an implementation of the six sigma method for ammonium nitrate (AN) content optimization in condensate production for a fertilizer company in Colombia. The paper aims to determine the levels for input variables in the process, to meet desirable standards for condensate quality in terms of ammonium nitrate content. Based on the DMAIC steps implementation, it was possible to establish the main variables affecting the condensate quality and their optimal levels to reach an ammonium nitrate content below 15,000 ppm. These results demonstrate the impact that a six sigma project may have on operational effectiveness and quality improvement for meeting the customer requirements
Analyzing collaborative learning processes automatically
In this article we describe the emerging area of text classification research focused on the problem of collaborative learning process analysis both from a broad perspective and more specifically in terms of a publicly available tool set called TagHelper tools. Analyzing the variety of pedagogically valuable facets of learnersâ interactions is a time consuming and effortful process. Improving automated analyses of such highly valued processes of collaborative learning by adapting and applying recent text classification technologies would make it a less arduous task to obtain insights from corpus data. This endeavor also holds the potential for enabling substantially improved on-line instruction both by providing teachers and facilitators with reports about the groups they are moderating and by triggering context sensitive collaborative learning support on an as-needed basis. In this article, we report on an interdisciplinary research project, which has been investigating the effectiveness of applying text classification technology to a large CSCL corpus that has been analyzed by human coders using a theory-based multidimensional coding scheme. We report promising results and include an in-depth discussion of important issues such as reliability, validity, and efficiency that should be considered when deciding on the appropriateness of adopting a new technology such as TagHelper tools. One major technical contribution of this work is a demonstration that an important piece of the work towards making text classification technology effective for this purpose is designing and building linguistic pattern detectors, otherwise known as features, that can be extracted reliably from texts and that have high predictive power for the categories of discourse actions that the CSCL community is interested in
Use of the microalga Scenedesmus obliquus to remove cadmium cations from aqueous solutions
The ability of a wild strain of Scenedesmus
obliquus, isolated from a heavy metal-contaminated environment, to remove Cd2+ from aqueous solutions was studied at several initial concentrations. Viable biomass removed metal to a maximum extent of 11.4 mgCd/g at 1 mgCd/l, with most Cd2+ being adsorbed onto the cell surface. A commercially available strain (ACOI 598) of the same microalga species was also exposed to the same Cd concentrations, and similar results were obtained for the maximum extent of metal removal. Heat-inactivated cells
removed a maximum of 6.04 mgCd/g at 0.5 mgCd/l. The highest extent of metal removal, analyzed at various pH values, was 0.09 mgCd/g at pH 7.0. Both strains of the
microalga tested have proven effective in removing a toxic heavy metal from aqueous solutions, hence supporting their choice for bioremediation strategies of industrial effluents.info:eu-repo/semantics/acceptedVersio
Collaboration scripts - a conceptual analysis
This article presents a conceptual analysis of collaboration scripts used in face-to-face and computer-mediated collaborative learning. Collaboration scripts are scaffolds that aim to improve collaboration through structuring the interactive processes between two or more learning partners. Collaboration scripts consist of at least five components: (a) learning objectives, (b) type of activities, (c) sequencing, (d) role distribution, and (e) type of representation. These components serve as a basis for comparing prototypical collaboration script approaches for face-to-face vs. computer-mediated learning. As our analysis reveals, collaboration scripts for face-to-face learning often focus on supporting collaborators in engaging in activities that are specifically related to individual knowledge acquisition. Scripts for computer-mediated collaboration are typically concerned with facilitating communicative-coordinative processes that occur among group members. The two lines of research can be consolidated to facilitate the design of collaboration scripts, which both support participation and coordination, as well as induce learning activities closely related to individual knowledge acquisition and metacognition. In addition, research on collaboration scripts needs to consider the learnersâ internal collaboration scripts as a further determinant of collaboration behavior. The article closes with the presentation of a conceptual framework incorporating both external and internal collaboration scripts
A model of online protection to reduce children's online risk exposure: empirical evidence from Asia
Children are surrounded by a variety of digital media and are exposed to potential risks that come with such easy accessibility. Learning how to be safe online is an important consideration for both children and their caregivers. The present study proposes an integrated model of online safety based on constructs from protection motivation theory and the health belief model, namely perceived severity of (and susceptibility to) risk, online self-efficacy, online privacy concern, and digital literacy. The study comprised a survey conducted among 420 schoolchildren aged 9â16 years. Using partial least squares-structural equation modelling, the results illustrated the presence of a negative effect of âperceived severity of online riskâ toward online risks, whereas the effect of âdigital literacyâ was found to be positive. Children whose perception of online risks was more severe were less exposed to online risks if they had higher âonline privacy concernsâ than the children with higher âdigital literacyâ who are more exposed to online risk. Results of the study show that engaging in safe online behaviour requires children to have a high perception regarding severity of online risks as well as knowledge of online privacy concerns. Online risks and opportunities occur in parallel. Consequently, the factors that increase or decrease risk may also increase or decrease the benefits
Ductility of wide-beam RC frames as lateral resisting system
[EN] Some Mediterranean seismic codes consider wide-beam reinforced concrete moment resisting frames (WBF) as horizontal load carrying systems that cannot guarantee high ductility performances. Conversely, Eurocode 8 allows High Ductility Class (DCH) design for such structural systems. Code prescriptions related to WBF are systematically investigated. In particular, lesson learnt for previous earthquakes, historical reasons, and experimental and numerical studies underpinning specific prescriptions on wide beams in worldwide seismic codes are discussed. Local and global ductility of WBF are then analytically investigated through (1) a parametric study on chord rotations of wide beams with respect to that of deep beams, and (2) a spectral-based comparison of WBF with conventional reinforced concrete moment resisting frames (i.e. with deep beams). Results show that the set of prescriptions given by modern seismic codes provides sufficient ductility to WBF designed in DCH. 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Label-free smartphone quantitation of bacteria by darkfield imaging of light scattering in fluoropolymer micro capillary film allows portable detection of bacteriophage lysis
Conventional methods for the detection and quantitation of bacteria are slow, laborious and require a laboratory. Microfluidic systems offer faster and portable testing, and smartphone cameras can record colorimetric or fluorometric bioassays, but this requires dye addition. Here, we demonstrate for the first time label-free smartphone detection of bacterial light scattering by darkfield microfluidic imaging to measure bacteria and bacteriophage lysis. A single LED and portable 3D printed imaging box allowed bacterial concentration and growth to be measured by direct imaging of bacterial light scattering. Bacteriophage lysis was detected within a 10-channel microfluidic device made from melt-extruded fluoropolymer micro capillary film, allowing rapid detection of host specificity. Elimination of unwanted reflections and optimising illumination angle are critical for successful darkfield bacterial imaging, with 15° giving maximal intensity. Bacterial sedimentation was directly observed within microfluidic devices, and detection sensitivity significantly increased by allowing bacteria to sediment for 30âŻmin. With this simple, low-cost, 3D printed system bacterial concentrations down to an optical density of 0.1 could be measured corresponding to 8âŻĂâŻ104 colony forming units (CFU) per microdevice, approaching the sensitivity of conventional spectrophotometers. Bacteriophage lysis could be detected at a range of starting cell concentrations. With a low starting cell concentration, the increase in light scatter signal with incubation was prevented in the presence of bacteriophage. Conversely, with high starting cell concentration, the light scatter signal detected at the start was clearly eliminated when phage were added, indicating this simple system allows direct visualisation of bacteriophage eliminating light scattering by lysis
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