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- Can we freeze purified monocytes which were isolated from PBMC?
Monocyte isolation is a time and cost comsuming procedure. Does cryopreservation change the characteristics of monocyte in term of immune responses?
it is practical to freez PBMCs and then isolate monocyres from frozen PBMCs as and when requiredFollowing
- Are there some well studied cases of the extrusion of native not carnivorous species by an invasive intruder with similar preferences?
I.e. not just the destruction of native species by predating, like with rats or Euglandina rosea, but replacing in some other way, concurrence for resources or something. Maybe on the islands or in the some insular habitats. Especially interesting with invertebrates (have a case with land snails). I need some references with examples in citable journals.
There is extensive literature for introduced freshwater fish species, though predation may be part of the problem, there is also aggressive behaviour and more effective use of food sources. Some examples below:
Barrier RFG, Hicks BJ. 1994. Behavioral interactions between black mudfish (Neochanna diversus Stokell, 1949: Galaxiidae) and mosquitofish (Gambusia affinis Baird & Girard, 1854). Ecology of Freshwater Fish 1994: 3: 93-99.
Bunkley-Williams, L. et al. 1994. The South American Sailfin Armored Catfish, Liposarcus multiradiatus (Hancock), a New Exotic Established in Puerto Rican Fresh Waters. Caribbean Journal of Science, Vol. 30, No. 1 -2, 90-94.
Crossman, E. J. 1991. Introduced freshwater fishes: a review of the North American perspective with emphasis on Canada. Can. J. Fish. Aquat. Sci. 48 (Suppl. 1): 46-57.
Deacon, J. E. et al. 1964. Some Effects of Introduced Fishes on the Native Fish Fauna of Southern Nevada. Copeia, 1964 (2): 384-388.
Gido, K. B. & Propst, D.L. 1999. Habitat Use and Association of Native and Nonnative Fishes in the San Juan River, New Mexico and Utah. Copeia 1999 ( 2): 321-332.
Kohler, C. C., & Courtenay, JR., W. R. 1986. Regulating introduced aquatic species: A review of past initiatives. Fisheries 1 1(2): 34-38.
Kohler, C. C., & Courtenay, JR., W. R. 1986. American Fisheries Society position on introductions of aquatic species. Fisheries 11(2): 39-42.
Morgan, D.L. & Gill, H. S. 2001. The green swordtail Xiphophorus helleri HeckeI (Poeciliidae): another aquarium fish established in the wild in Western Australia. Records of the Western Australian Museum 20: 349-352.
Schoenherr, A. A. 1981. The role of competition in the replacement of native fishes by introduced species. Pp. 173-203. In: Naiman, R.J. & Soltz, D. L. eds.: Fishes in North American deserts. New York.Following
- What are the best methods to obtain high quality RNA from diatom?
Our problem is relative to the disruption methods, we tried different methods like, sonication, grinding with beats, and liquid nitrogen, although we get some results we did not obtain an high RIN yet.
Someone have a different protocol?
Thanks in advance.
Dear Sarang thank you for your answer, the article was really interest but they do not pay really attention to the quality of the RNA yield, anyway we follows their procedure without obtain good result.
- Is there a difference between "research questions" and "research objectives" or "research goals" in qualitative research?
I remember being told during my studies that in QR one does not ask "questions" of the data, but rather sets objectives or goals for the research. As far as I can understand, this is guided by the notion that one does not know at the outset of the research what it is he or she is to ask.
Can anyone elaborate on this? Or else refer me to a place where such a distinction is made clear?
There is a clear distinction, at least between research questions and research goals/objectives. The latter distinction is less clear.
Research questions are empirical or non-empirical questions that address an extant research problem. Empirically, they can be exploratory, descriptive, explanatory, evaluative, predictive, and historical. Non-empirically they can be meta-analytic, conceptual, theoretical, or normative.
Research goals can represent the overarching 'purpose' of the research (to explore/to explain/to describe phenomenon X so to address gap in knowledge Y) whereas research objectives are subsets of goals, in which particular objectives have to be achieved so to achieve the overarching goal(s).
Inherently, interpretive and exploratory research (in the constructivist paradigm) face the philosophical difficulty of induction versus deduction, i.e. "how can I know which questions to ask if I haven't done the research?". Grounded theory is one means for addressing this anomaly, where ordinarily research questions are derived from a systematic review and analytic reading of the literature.
I am a proponent of the emergent and iterative principles that grounded theory espouses, namely that we can formulate initial research questions, but that these too will emerge (and likely change!) as the research progresses, e.g. through interpreting the empirical data or non-empirical phenomena. This is for example typical of more anthropological/ethnographic studies, where strictly methodological concepts of "data" and "research questions" are not as germane as in problem-based research.Following
- What is the difference between cluster radius and threshold distance in clustering in WSN in hierarchical protocols such as HEED?
In WSN in hierarchical protocols such as HEED protocol, the range of cluster head is identified by cluster radius which is smaller than threshold distance (d0 = 87). Why don't we use the threshold distance rather than cluster radius? What is the difference between them?
Thank you so much.
Why we don't use the threshold distance as a cluster radius? We know that the network life-time increases as the value of radius increases.Following
- Do you think that salt accumulation plays the leading role in plant leaf shedding process in saline condition?
Do you think the Na+ or Cl- accumulated in leaf could lead to the leaf abscission?
In high saline condition, what's the major factors trigger the leaf abscission?
I am looking forward to your reply! Thx!
Thank you for your time to help me ! Best wishs1Following
- Is it possible to chip small mammals?
Hey hallo, I want to mark shrews (Neomys fodiens, N. anomalus, Sorex araneus and S. minutus) for recaptures. The field study shall last 12 month. In the past, I tattooed them with high effort at their tail.
Is it possible to use small microchips? These chips are already in use by vets for marking cats and dogs. But I think that these are too large for small mammals, especially for Sorex minutus.
Does a kind of a very small microchip exists, which I can use for marking these small mammals?
We successfully used standard microchips for marking shrews, including pygmy shrew. They will live with it, but there is a big risk of injury. Moreover, they quite easy loose the tags, so toe clipping seems to be good alternative method. In some studies we mark small mammals using both chips and toe clipping. If you want to read small tags you need reader with big antennae otherwise you must literally touch the tags to read it.Following
- Does anyone have experience with GDNA extraction-Medicago truncatula?
I currently working with M. truncatula and I am trying to perform some gDNA extraction out of leaf tissue. I have been using the following extraction buffer: 200mM Tris,pH7.5, 250mM NaCl, 25mM EDTA and 0.5% SDS. My supernatant volume is mixed with isopropanol (equal volume as my supernatant) and incubated for 10 min, then centrifuged for 7 mins. Then the pellet is resuspended with 70% ice-cold ethanol and then centrifuged again for 2 mins. I let my pellet dried and then resuspended with ddH2O.
I have used this method and always, my pellet turned out orange or pink. I am trying to obtain good quality of gDNA. Any suggestions?
Try Murray and Thomson 1981 protocol. I am using this protocaol since 2003 and I have got good quality of gDNA always whether it is plant, Bacteria or fungus. The Protocol is as below
Tris HCl pH 8.0 ------------------- 100 mM
EDTA pH 8.0-------------------------20mM
Heat samples at 65 deg for 1 and Half hours with constant starring
Cool the samples and add chloroform isoamyl alchol 24:1 and agitate
spin at 10000 rpm for 15 min
collect supernatant and transfer to other tube and then add chilled isopropanol (equal vol.) and left at -20 deg for overnight
centrifuge and wash the pallet with 70% ethanol, dry and suspend in TE buffer
Hope it will yield good quality DNA
- Total RNA Extraction from a human fresh whole blood (kit #K0871). I don't understand my results. Please help me!!!
I have recently extracted total RNA from a human fresh whole blood (kit #K0871 - Thermo Scientific GeneJET Stabilized and Fresh Whole Blood RNA Kit). To verify the integrity of samples, I proceeded to check RNA samples on 1% agarose gel. For humans the 28S and 18S ribosomal RNA bands should appear at approximately 5kb and 1.9kb respectively. But I don’t received these bands (except gel 1, probe P4). I don’t know if these bands are RNA. Then I don’t know what represents the bands at the top of the gel, may be this is genomic DNA? Because in many article says that if the RNA is contaminated with DNA genomic in gel appear the band at ~20 kb I think that this is not DNA genomic, but I don’t sure. Please help me understand these results.
Probe 1 and P4 – 500 ul blood + Lysis buffer Protocol B kit #K0871
Probe 2 and B2 – 500 ul blood + 1,3 ml RNAlater Protocol B kit #K0871
Probe D3 – 600 ul blood + 1,3 ml RNAlater Protocol D kit #K0871
T1.1 – TriReagent (AM9738)
M – marker #SM1551 (GeneRuler Express DNA Ladder – 5000pb)
Gel 1 and 2 – agarose gels was run at 140 V
Gel 3 – agarose gels was run at 65 V
Thank you in advance.Following
- Is there a higher risk of lightning-induced forest fires near electrical infrastructure? Is there any indication that lightning prefers sites near electrical power lines, e.g. high-voltage power lines or power lines of railway systems?Following
- Can anyone help with the best simulator for hetNetwork for Demand Response (DR) in smart grids?
Going to start simulating a model of DR. Any suggestion of best simulator, where it would be easy to simulate DR model with HetNet ....
@Samaresh Bera - Did you use it for the DR/DER purpose?Following
- Could someone tell me about any algorithm that works well in face recognition by composite sketch?
Could someone tell me about any algorithm that works well in face recognition by composite sketch?Following
- What in your view is an innovative teaching method?
Many experience teacher had used different method of teaching to attract or to improve the quality of sharing knowledge with students. How do you design the teaching to become innovative method?
I completely agree with Dr. Kamal. Teaching must create a fluid communication between students and teachers. If you can capture their attention and their involvement in the class, the learning experience will be really productive. Any method getting this aim could be considered innovative (in my view). I'm teaching Neuroscience. However, at the very beginning of the class I project photographs from very different places (cities, landscapes...). They have to guess which place was projected and afterwards I tell a brief story about that place. They get relaxed and participative and two minutes later, being unaware of that, were are speaking about the brain.Following
- Has 'academic' feminism achieved any practical results?
One can categorize feminism, broadly of course, into 'academic' and 'political'. There have been a number of achievements for political feminist activists, whether they be legal, social, domestic, etc.
However, do you think academic feminism has been able to take any significant practical measures towards liberation/emancipation/empowerment of women?
I guess, the other speakers are right in highlighting the common ground of the different fields of activity of feminism - I could add the concept of "free space" that academia could provide for feminism... and argue that many of the feminists in academia do not participate in the social movement feminism.
Concerning your question, I think a major contribution of "academic feminism" is the inclusion of gender into the analysis of different factors of inequality - together with class and ethnicity, as the intersectionality approach does. This is indeed an epistemic break that changed the ground on which research is done.Following
- How can we perform the detection of mitocondrial DNA (mtDNA) in living or fixed animal cells with confocal microscopy?
How can we perform the detection of mitocondrial DNA (mtDNA) in living or fixed animal cells with confocal microscopy?
thanks for suggestions, I start working!!!Following
- Social media: Downvoting and degrading in social networks – What are the reasons? - What are the reactions? We have recently seen a lot of down-votings in some threads. We also saw different kinds of reactions on this phenomenon. I would like to ask a question about these reactions.
First I assume that there are several possible reasons for downvotings: dissent – misunderstandings – misuse of buttons without knowing it– a social scientist who writes a paper about the reactions – a test carried out by RG – some technical problem, etc.
I would like to have a discussion about the reactions on the part of researchers. We have seen calls to ban down-voters or to cancel their anonymity. Elections in democracies are anonymous and there are good reasons for this. I think most of us agree about some basic traits of democracy, the right to stay anonymous is among them. What about these basics in social media?Following
- How would you test if a batch of TNF-alpha is biologically active?
I want to check if a batch of TNF-alpha is still biologically active and I am wondering if anyone knows the best way to do that? What readout after stimulation of cells with the TNF would give the most accurate quantification of the activity of that TNF?
Thank you for the help. I will get some endothelial cells and try this technique.
- Has anyone evaluated the role of Acemannan in treatment of periodontal disease? Has it been worked on? Acemannan is an extract from Aloe vera
Is it available commercially?Following
- I am looking for specialists in order to identify arthropods from Djibouti. Can you help?
For 4 years, I have collected arthropods from Djibouti. Now I need help to identify them.
I can probably help with any acridoid grasshoppers you have. (Not, however, with crickets or katydids). Please send some specimen photos! firstname.lastname@example.orgFollowing
- Can you please suggest a diagnosis for someone with hepatosplenomegaly, thrombocytopenia, neutropenia and microcytosis?
A 45 year old male patient presented to me with hepatosplenomegaly, thrombocytopenia, neutropenia and microcytosis. He has recurrent lung abscees. He was treated as pulmonary tuberculosis initially 3 years back and HIV also was ruled out. His bone marrow examination is normal. Again he was started on anti TB drugs recently for lung abscess considering a relapse of TB. We have stopped ATT as he developed alteration in liver profile.Tuberculosis and anti TB drugs also can cause bicytopenia. But microcytosis cannot be explained.Is it an immunodeficiciency syndrome?
Does inflammation like Tuberculosis causes microcytosis?Following
- Do you have national strategy for health in your country and if so how effective it is?
National health strategy in different countries and its applications
Well, a national strategy may be their but its implementation depends on the political will of the government of the day.Following
- What are the main drawbacks of conventional anti-malarial therapy ? Conventional antimalarial therapy has numerous disadvantages as far as the patient is concerned. I am looking for the major disadvantages which are preventing the therapy to be utmost useful as far as its action is concerned
A major limitation includes drug bioavailability at target site.Following
- How to remove copper after CuAAc click reaction?
I am using CuAAc click reaction to functionalized antimicrobial polymer colloids particles which has positive charged group on it. Is anyone know how to purify my product after cilck reaction?Following
- Do you know an alternative to Hough transform to detect circles/ellipse/spots?
I tried Hough transform but it is too noisy. Do you know a better way to detect spots/circles/ellipse?
Some examples of data:
- How can we determine the sample size from an unknown population?
How can we determine the sample size from an unknown population in tourism studies?
If key-variable of the population is quantitative, use n=Z2*s2/d2. Where: n - this is what are looking for (minimum sample size), Z - is the value of the distribution function (for tourism phenomenons you can calculate this value for alpha equals to 0,05), s - is the population standard deviation, and d - is acceptable standard error of the mean (it is up to you). Of course, you don't know the population (typical in tourism studies). So, I suggest to estimate s using results from pilot research. After the pilot research calculate s=s'*(n'/(n'-1))^0,5. Where: n' - is the sample size of pilot research, and s' - is the the standard deviation of sample of pilot research. I know that it's not a perfect solution. There is lot of limitations, e.g. using convenience sampling for pilot research.Following
- Why do we have peaks that are not pesticides that we already know in pesticide residue analysis?
When using the instrument (GC or HPLC) for pesticide residue analysis, we found that there are many peaks that are not pesticides we already know , Also the peaks are not from chemicals of pretreatment and matrix. Then how do we know whether composition of these peaks is toxic or not ?
there may be different reasons for the appearance of the unexplained peaks
1. Due to unknown impurities or artifacts in the HPLC or GC system.
2. Due to matrix effects which may not be eliminated during the clean-up process.
3. Due to unstable detector response which may give false peaks.
4. Use of impure solvents
Confirm the purity of the standards, confirm the column specifications so that you use the right column for the samples, ensure that the column is clean and run blank samples in between sample runs. Only standards of high purity can confirm m the presence of the compounds in samples.
Hope above information is of help to you.
- How to set up HPLC validation for budesonide Dry powder inhelar pharmacokinetic in mice?
Most of the articles I came across for an above sited topic, I found validation with LC-MS, HPLC-MS/MS. Why I can't go with HPLC, though LOQ and LOQ of BUD were 2.29ng/ml and 6.96ng/ml respectively for my validated HPLC method.Following
- Is the atherogenic index of plasma (AIP) a better marker of atherosclerosis than LDL/HDL in asians?
NCEAP ATPIII and various guidelines point out that LDL/HDL is an important predictor of atherosclerosis. But in clinical practice I found that log of TG/HDL (Atherogenic index of plasma) as an important marker in South Asians.
We do observe this relationship in patients with cardiovascular events. At the moment doing a small hospital based study among stroke patients comparing LDL/HDL vs AIPFollowing
- How do you best evaluate nurse’s knowledge of dysphagia by quantitative research?
In my masters thesis I am evaluating nurse’s knowledge of dysphagia. I would like to discover where the main problems (lack of knowledge) are and develop a standard to help them and make a patient care safer. In my questioner I included assessment of nursing practice, professional training and academic knowledge. Unfortunately I haven’t found any similar study to compare it with and so I have developed my own questioner. Has anyone evaluated nurse’s knowledge of dysphagia? In our hospitals SLT (Speech Pathologists/Therapists) are included after nurses perform the patient evaluation. If you have any information about any study I would appreciate it.
Thank you Carol,
yes, I also agree that dysphagia should be viewed as a patient safety issue and nurses are the ones that should recognise the signs first. Population is getting older and dysphagia will be even a bigger problem.
Evaluating a novel approach to enhancing dysphagia management sounds very interesting I am looking forward to reading it.Following
- Will there be a difference in the concentration of water soluble constituents when method of extraction is different although solvent is the same?
Using water as a solvent for extraction, two processes were used as described below:
1. Fresh leaves of the plant collected and instantly extracted with hot water.
2. Leaves were collected, then sun drying carried out, followed by extraction with water.
Among the above two methods, the concentration of active ingredient was found to be appreciably higher in process 1.
Following process 2, the yield was very low. Solvent was hot water in both cases.
Does it has something to do with the use of fresh leaves and drying leaves in the sun. Heat is applied in both the cases but results are different. Suggestions are welcome.
There is lot of difference in the yield. In wet / fresh tissues, due to water content, yield is reduced, whereas, in case of dry tissue, the yield is normally high. If you determine extractive value, you will find the difference.Following