263 research outputs found
Bovine serum albumin further enhances the effects of organic solvents on increased yield of polymerase chain reaction of GC-rich templates
Background
While being a standard powerful molecular biology technique, applications of the PCR to the amplification of high GC-rich DNA samples still present challenges which include limited yield and poor specificity of the reaction. Organic solvents, including DMSO and formamide, have been often employed as additives to increase the efficiency of amplification of high GC content (GC \u3e 60%) DNA sequences. Bovine serum albumin (BSA) has been used as an additive in several applications, including restriction enzyme digestions as well as in PCR amplification of templates from environmental samples that contain potential inhibitors such as phenolic compounds. Findings
Significant increase in PCR amplification yields of GC-rich DNA targets ranging in sizes from 0.4 kb to 7.1 kb were achieved by using BSA as a co-additive along with DMSO and formamide. Notably, enhancing effects of BSA occurs in the initial PCR cycles with BSA additions having no detrimental impact on PCR yield or specificity. When a PCR was set up such that the cycling parameters paused after every ten cycles to allow for supplementation of BSA, combining BSA and organic solvent produced significantly higher yields relative to conditions using the solvent alone. The co-enhancing effects of BSA in presence of organic solvents were also obtained in other PCR applications, including site-directed mutagenesis and overlap extension PCR. Conclusions
BSA significantly enhances PCR amplification yield when used in combination with organic solvents, DMSO or formamide. BSA enhancing effects were obtained in several PCR applications, with DNA templates of high GC content and spanning a broad size range. When added to the reaction buffer, promoting effects of BSA were seen in the first cycles of the PCR, regardless of the size of the DNA to amplify. The strategy outlined here provides a cost-effective alternative for increasing the efficiency of PCR amplification of GC-rich DNA targets over a broad size range
Analisis Efektivitas Pembelajaran Daring Pada SMK Dengan Metode Asynchronous dan Synchronous
Pandemi covid-19 memberikan pengaruh yang besar terhadap dunia pendidikan, sehingga menyebabkan terjadinya beberapa perubahan terutama pada metode pembelajaran. Kementerian pendidikan dan kebudayaan memberikan peraturan bahwa metode pembelajaran yang digunakan pada masa pandemi yaitu metode pembelajaran daring. Tujuan penelitian ini adalah mengetahui analisis efektivias pembelajaran pada pendidikan vokasi dengan metode asynchronous dan metode synchronous. Jenis penelitian ini adalah penelitian kuantitatif dan model penelitian desain eksperimen (quasi-experiment) dengan non-equivalent control group design. Subjek penelitian adalah SMK N 2 Padang. Populasi dalam penelitian ini adalah siswa kelas XI RPL yang berjumlah 68 orang. Teknik analisis data menggunakan Uji Normalitas – Gain (N-Gain) dan Uji-T untuk kedua kelompok sampel. Nilai N-gain pada pada kelas eksperimen sebesar 53,77%, sedangkan kelas kontrol nilai N-gain sebesar 59,30%. Berdasarkan hasil uji-T terdapat perbedaan yang disignifikan antara hasil belajar peserta didik dengan metode pembelajaran asynchronous dan metode pembelajaran synchronous. Tingkat keefektivan terjadi pada metode synchronous dengan menggunakan video conference, sehingga penerapan metode synchronous dapat meningkatkan hasil belajar siswa
The 'double face' illusion
We report three experiments intended to characterise aspects of the ‘double’ face illusion, formed by replicating the eyes and mouth below the originals. Such doubled faces are disturbing to look at. We find there are wide individual differences in ability to detect that a face has been doubled when presented briefly and masked. These differences appear to relate to perceptual speed, since they correlate with the ability to identify a briefly presented famous face. Doubling has a significant effect on identification, though much less than inversion. In a reaction time study, participants are faster to decide that a face has been doubled as it is rotated away from upright. The final study shows that normal and doubled faces do not pop out from each other, but reveals a processing overhead of 40-60ms per doubled face. We offer some speculations as to the cause of the perceptual effects
Human-derived nanoparticles and vascular response to injury in rabbit carotid arteries: Proof of principle
Self-calcifying, self-replicating nanoparticles have been isolated from calcified human tissues. However, it is unclear if these nanoparticles participate in disease processes. Therefore, this study was designed to preliminarily test the hypothesis that human-derived nanoparticles are causal to arterial disease processes. One carotid artery of 3 kg male rabbits was denuded of endothelium; the contralateral artery remained unoperated as a control. Each rabbit was injected intravenously with either saline, calcified, or decalcified nanoparticles cultured from calcified human arteries or kidney stones. After 35 days, both injured and control arteries were removed for histological examination. Injured arteries from rabbits injected with saline showed minimal, eccentric intimal hyperplasia. Injured arteries from rabbits injected with calcified kidney stone- and arterial-derived nanoparticles occluded, sometimes with canalization. The calcified kidney stone-derived nanoparticles caused calcifications within the occlusion. Responses to injury in rabbits injected with decalcified kidney stone-derived nanoparticles were similar to those observed in saline-injected animals. However, decalcified arterial-derived nanoparticles produced intimal hyperplasia that varied from moderate to occlusion with canalization and calcification. This study offers the first evidence that there may be a causal relationship between human-derived nanoparticles and response to injury including calcification in arteries with damaged endothelium
Measuring water use in a green economy, A report of the Working Group on water Efficiency to the International Resource Panel
Information from physicians and retention of information by patients – Obstacles to the awareness of patients of progressing disease when life is near the end
<p>Abstract</p> <p>Background</p> <p>Discrepancies between the information that patients have received and the patients' awareness of their condition have frequently been observed in literature and given a number of different explanations. The chief contribution of this study is that by following patients over time it is possible not only to notice any changes in the patients' knowledge or awareness of their disease, but also to investigate the interview material for possible reasons for those changes. Since the study is based on two different groups of patients it will also be possible to notice if the category of disease matters for patients' awareness of their condition.</p> <p>Methods</p> <p>Twelve patients with malign haematological diseases or lung cancer were followed with interviews from diagnosis to cure or death, or at most for two years. The method is qualitative. Semi-structured interviews were conducted, transcribed into written text, and then used for a qualitative content analysis.</p> <p>Results</p> <p>During the process of analysis four different expressions (subcategories) emerged about the awareness of patients concerning their health status: informed and aware, not informed and not aware, aware though not informed, or not aware though informed. Then the search started for obstacles to the awareness of patients regarding their progressing disease and approaching death. Four kinds of obstacles were found: due to the physician, the patient, the physician and the patient in collusion, or neither to the physician nor the patient but the insidious way in which lung cancer (mostly) and haematological malignancies (occasionally) progress.</p> <p>Conclusion</p> <p>To optimize the care of patients who wish to be informed and aware during their disease, it is important that the health care staff recognizes potential obstacles to the awareness of patients in order to minimize such obstacles. The physicians could improve their communication with patients with life-threatening diseases, and avoid having a narrow focus on the treatment calendar. The patients could be encouraged to have a more proactive attitude in their communication with their physician.</p
The bodily presence of significant others: Intensive care patients' experiences in a situation of critical illness
This study is about intensive care patients and the bodily presence of significant others. The aim of the study is to inquire and understand the patients experience of the body in relation to their significant others during critical illness. Open, unstructured, in-depth interviews with six former intensive care patients provide the data for the study. The phenomenological–hermeneutical analysis points to a theme among ICU patients' experience of conflict between proximity and distance during the bodily presence of their relations. Patients experience different and conflicting forms of responses to the presence of their significant others. Patients experience significant positive confirmation but also negation through this presence. In the ICU situation, the reactions of significant others appear difficult to deal with, yet the physical presence is significant for establishing a sense of affinity. Patients seek to take some responsibility for themselves as well as for their relatives, and are met with a whole spectrum of reactions. Intensive care patients experience the need to be actively, physically present, which often creates sharp opposition between their personal needs and the needs of their significant others for active participation
A habituation account of change detection in same/different judgments
We investigated the basis of change detection in a short-term priming task. In two experiments, participants were asked to indicate whether or not a target word was the same as a previously presented cue. Data from an experiment measuring magnetoencephalography failed to find different patterns for “same” and “different” responses, consistent with the claim that both arise from a common neural source, with response magnitude defining the difference between immediate novelty versus familiarity. In a behavioral experiment, we tested and confirmed the predictions of a habituation account of these judgments by comparing conditions in which the target, the cue, or neither was primed by its presentation in the previous trial. As predicted, cue-primed trials had faster response times, and target-primed trials had slower response times relative to the neither-primed baseline. These results were obtained irrespective of response repetition and stimulus–response contingencies. The behavioral and brain activity data support the view that detection of change drives performance in these tasks and that the underlying mechanism is neuronal habituation
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