ResearchGate Q&A lets scientists and researchers exchange questions and answers relating to their research expertise, including areas such as techniques and methodologies.
Browse by research topic to find out what others in your field are discussing.
- NewReason for necrosis followed by spontaneous regression of tumor in xenograft model?
Hello to everyone,
I'm working with HCT116 xenograft model in NCr Nude mice. All of sudden i came across the problem of tumor necrosis followed by spontaneous regression of tumor and sudden weight loss too. Anybody can help me to sort out trouble shooting in this regard?
I wonder if you have determined levels of cytokines in sera of your mice. If not, you may consider this. Speculatively, cell death-associated release of cellular DNA induced innate immune responses in NCr nude mice resulting in tumor regression and weight loss. However, other possible explanations can not be ruled out based on your limited information.Following
- 8Do the dielectric-temperature maxima correlate with the high temperature impedance spectroscopy in ferroelectric relaxors?
As we all know, the dielectric-temperature spectra of ferroelectric relaxors are dispersed. High temperature impedance spectroscopy can be utilized to seperate the impedance contribution of grain, grain boudary, electrodes, etc. The question is whether the maxima of the dielectric-temperature spectra has any relationship with the high impedance spectroscopy. I am very confused because one reviewer raised such a question on the explaination of the suppression of the dielectric maxima with different doping concentration in our relaxor system through the differing contribution of Cgb (the capacitance of grain boundary retrieved from the high temperature impedance spectroscopy). To my knowledge, the dielectric maxima is due to the existence of polar clusters/regions, while the high temperature impedance spectroscopy is conducted at temperatures (> 500 deg C) well above the dielectric-temperature maxima (<50 deg C), the relaxation of which was reported to be ion hopping. The contributions to the permittivity of the two kinds of spectra should be different. I wonder how the two can be correlated? Any help or discussion is appreciated in advance!
Dear Petr Viscor,
Thank you very much for you suggestive answer. The problem is that the dielectric-temperature peak which is literaturally reported to be due to dipoles, appears at low temperatures. I have not conducted impedance spectroscopy at that temperature. It seems true that to distinguish the response whether intrinsic(bulk) or extrinsic, impedance data should be collected at the same temperature region. Nevertheless, from my previous experience, at lower temperatures, it is difficult to obtain complete cole-cole circles because the impedance is over high, especially when the dielectric relaxation temperature of our material system is at < -80 deg C. Any suggestions or opinions on the low-temperature EIS? Thank you!
- 3What is casimir energy ,force or effect ? What is dark energy ? and what is the connection between the two ?
Tthis is a fundamental question in physics and cosmology
If the Sun is surrounded by a thick soup of dark matter, we ought to be able to see its gravitational influence on the orbits of the planets, moons and asteroids.Following
- 13The Heckscher-Ohlin theory is preferred to the Ricardo theory by economists because it makes fewer simplifying assumptions. What is your view?Http://www.rulemic.com/hecks.html
of course, the factor price equalization theorem does not hold out of factor price equalization cone, but is it a good theory to analyze wage differentials between countries?
You have mentioned Jones (1970). I suppose it is the paper with the title "The role of technology in the theory of international trade." Did Jones analyze the HO model with the same technology for two countries?
In section I, Jones examines "the general case in which production functions are allowed to differ between countries." (p.74) This is already a bit different from the standard HO model, which assumes the same technology for both countries.
In section II, Jones examines what he calls modified Heckscher-Ohlin model. He willingly admits that his modified "Heckscher-Ohlin model represents a step backward from the earlier Ricardian tradition." (p.78) It does not seem to me that Jones examines the case of perfect specialization. What Jones examines as his "modified HO model" is the case where "the two countries differ only slightly in their technologies.small modification." (p.83) It is quite doubtful if Jones examined the case of "complete specialization". He only observed slightly modified state of the factor price equality case. By his method, he cannot examine the case where the wages differs in a large extent (workers of a country gains in the same working time ten to twenty time more than workers of the other country).
However, these are only a minor point. What is more important for HO model is the assumption that factors are predetermined quantities. We can suppose that workers stay in their original country, but how about capital or more precisely input goods (or intermediate products)? They are traded as freely as final goods. Some reports that this part of trade (proportion of input trade) is increasing. As Jones admits, "the entire concept of factor abundance is subject to question if capital is mobile between countries." (p.84)
You should know that we have now very general Ricardian theory (M-country, N-commodity case with trade of intermediates goods and choice of techniques). Why should we stick to a very restricted theory? At last account, what Jones succeeded is the case of two-country, two-goods and two-factors. It may work as a parable, but theorems do not generally hold in the higher dimensional case. What is the merit to adhere to such a restricted model?Following
- 1What is the the acceptable analytical limit of error of muscle temperature measurement?
Muscle temperature, particularly of the VL, is regularly used as a thermoregulatory measure in studies of environmental heat stress and exercise regulation.
However, many of these papers simply make reference to significant changes. I am therefore wondering if there are any papers that make reference to the acceptable analytical limits of error of muscle temperature measurement?Following
- 2Any guidance on the procedure to get the natural frequency of a plate with general boundary condition?
Pse guide on the proceedure to get the natural frequency of a plate with general boundary condition?
The natural frequencies depend upon the specific (not general) boundary conditions just as they depend upon the properties of the plate itself (i.e. its geometry and material properties).Following
- NewEntopy of image histogram?
Does someone know the minimum and maximum values that the entropy can range when computed from an image histogram?Following
- 24Could you please tell your point of view on the current situation worldwide ?
Is it a stable or fluctuating and we are faced to the glabal danger
I agree with Kausel. It seems to me that we have miserably failed in learning from history.Following
- NewPlease let me know how to perform T1 quantification and mapping using spin echo sequence?
And are there any free softwear for T1 mapping and quantification?Following
- 7What are the ethical issues of RFID?
I am doing a research regarding the ethical issues of RFID on employees or refugees. After what happened in France, it seems that governments are thinking of using bracelets to track refugees in their countries or wanted people. The same in case of employees... I read few articles and found few ideas, but I would benefit from your experience.
- 2Can anyone share their recent findings on Impact of product Design on buying behavior?
Any model regarding influence of product design on word of mouth and purchase intention.
check out my recent published study concerning clothing brands. Some of the concepts and analysis might be usefulFollowing
- 99+What are the best cognitive tests for detecting early changes prior to the onset of dementia?A traditional approach is to use tests of global cognitive function such as the Mini-Mental State Exam (MMSE: Folstein et al., 1975) or the Blessed-Information-Memory-Concentration Test (BIMC: Blessed et al., 1968) to assess the severity of cognitive impairment (Tombaugh and McIntyre, 1992). But are these tests sensitive enough? Most studies show either ceiling or floor effects according to the time progression into disease.
The Rapid Cognitive Screen(RCS) can be done in 3 minutes and picks up most people with MCI as well as dementia. The SLUMS at 6 and a half minutes is very good for cognition, visual spatial and executive function. Both are better than the MMSE and equivalent to the MOCA a. The AD8 picks up dementia but not MCI. the St Louis University Lewy Body Screen can be used for Lewy Body DementiaFollowing
- 1Does anyone has an experience of growing SCC-4 cells from ATCC without feeder cells?
It would be nice to grow them using some coating, conditioned media, etc. instead of feeder layer.
I have some experience of growing SCC-4 cell line without feeder layers, wich have been obtained from ATCC. Cells were maintained in F12/Dubecco’s Modified Eagle’s Medium (DMEM) media (Sigma Aldrich, Germany) or DMEM/HAM's F12 1:1 supplemented with 10% fetal bovine serum (FBS) ), 1% penicillin, streptomycin, 15mM HEPES, 1mM Sodium pyruvate (Life Technologies GmbH, Darmstadt, Germany) and 400 mg/ml hydrocortisone (Sigma, St. Louis, MO, USA) and maintained at 37 C in a 5% CO2 air atmosphere. The medium was changed every 2 days and cells were passaged after reaching 70-80% confluence.
- 30How can we expand the sink capacity of soil for carbon storage?
We very often raise the issue of declining soil fertility on account of depletion in carbon pool of the soil , which probably has equally revealing implications on plant health. An enriched carbon pool of soil has has many ecological functions to serve, besides safeguarding the quality of the soil against soil degradation forces. But, our experiences reveal it is probably equally difficult to elevate the carbon storage capacity of the soil, regardless of practices. I have the following set of questions to my learned colleagues to respond:
* How far different fertilization practices aid in building the carbon pool of soil irreversibly (Not lost back to atmosphere)?
* How can we ensure what fraction of soil carbon pool is aiding towards soil health and plant health?
* How can we decide the capacity of different crops to sequester the atmospheric carbon in plant canopy framework?
* Do you feel carbon pool of soil dictates the carbon storage capacity of plant?
* How can we correlate the soil carbon pool and ecological service in a given agro-ecosystem?
* How far conservation agriculture is effective in improving the soil carbon pool in irrigated areas?
The labile carbon pool is the Carbon source for feeding the microbial C pool. Ultimately the ability of microbes and plants will be most limited by scarcity of water. It is the passive Carbon which is mostly associated with that critical water function I believe.
Labile carbon will lead to passive Carbon over time and when it accumulates the water relations will improve both in the physical structure of the soil but also the reserve capacity to store and deliver scarce water.
E Hadavi is right to stress that readily available external inputs have untoward effects on the biological systems. I concur. The ability to promote diverse plant cover will maximize the Carbon sequestration capacity and potential of the soil. In relation to global warming and drought mitigation it is good to focus on accrual in passive Carbon which is key to those effects for top yield potential and as potent of future ability to predict Carbon sequestration labile Carbon pools are good indicators.
The microbial mass and activity active and passive Carbon are all correlated and probably can be used to predict each other.Following
- 33Is analogy the key to understand thinking?
Hofstadter and Sander write in their book "Surfaces and Essences: Analogy as the Fuel and Fire of Thinking" that analogy is a key issue for cognition and perception. They put analogy into the center of all mental tools. I think analogy is a powerful tool but it is a tool beside others.Following
- NewAre there any modified QuECH method to analyze bitertanol pesticide in black tea using LCMS/MS coupled with C-18 column ?
Accepted methodology, solvent for analysis, solvent ratios with time plan, black tea sample extraction procedure for minimum matrices and colour figments effects.Following
- NewIs there any analog of pseudo force if we take the Einstein field equation in non inertial frame?
Is there any analog of pseudo force if we take the Einstein field equation in non inertial frame of reference rather taking newton's second law with pseudo force concept?
Instead my simple doubt is that is there any physical reason of pseudo force?Following
- NewImpedance functions with negative Re and Im parts
When calculating foundation impedance functions in the frequency domain (with SASSI or Wolf's Cone Method) for some frequency intervals (usually between 5 and 10 Hz) the Re and Im parts become negative. This is more pronounced for layered sites and embedded foundations. Is there a physical explanation or it is a numerical issue? If it's numerical, what Re and Im values should be used instead of these negatives?Following
- 12Can you name a soil moisture point between Saturation and Field Capacity? How can I define it for different soil textures?
I have a number of hourly time series of soil moisture. In these time series, TDR never measured values near soil saturation, but my max values were alway at a certain point between Saturation and FC. So I thought maybe there is really a soil moisture point between Saturation and FC.
There is also the problem of whether the soil structural units (peds) actually collapse to form a homogeneous water-soil mix. Many soils, particularly in humid tropical regions tend to have peds that resist collapse when wetted. It is usually only the solontz-type soils of arid regions that readily collapse into a jelly-like mass when wetted. The interiors of the larger peds take a considerable time for the increased moisture to penetrate into the centre of the peds, by which time, the mass is already drying out. Although field capacity can be achieved in specially mixed soils in laboratories, the situation in the field is rather different.
If you really want to measure field capacity in the field, you have to find a flooded soil and then monitor the change in moisture content as it dries out. At first, draining the excess water will result in fairly rapid reduction in water content, but this should decrease with time. It is unlikely that there will be an abrupt change in water content of the soil at field capacity, because the drying process will be continuous. However, the rate of change will be lower and water will cease draining out of the soil mass into the drainage channel.Following
- NewHello researchers , can any one help me and give me aprocedor of synthesis of 3-oxobutanenitrile ( 1 cyanoacetone) ?
the proedors and condition of reactionFollowing
- NewDoes anyone have information about backwater floods?
I am looking for examples of backwater floods, especially in urban areas. I mean the situation when flood on the main river causes floods on tributary.Following
- NewPlease...,anyone give the guidance to perform SEM and MIP tests on Bentonite clay?
My project is on Analyzing the Ageing effects of expansive clay soil ; Micro-structure approach.For this, I need to perform Scanned Electron Microscopy(SEM) and Mercury Intrusion Porosimetry (MIP).I had some confusions while performing these tests(sample preparation,how I can conduct SEM test for compacted samples etc).Please suggest any journals regarding this.Following
- NewBPRS version 4.0 in Dutch?
I am interested in using the Brief Psychiatric Rating Scale - 24 (BPRS-24), version 4.0, which is a newer version of the BPRS. Is there anyone who knows whether this scale has already been translated into Dutch?
- 5What's the best way for warehousing gait analysis data?
3D gait analysis laboratory generates a huge amount for the subject.For many subjects such normals and abnormals gait, what's the best way to store these data so that we can do different statistical processing on them later. should we save the gait cycle data as rows or columns Are there any software for gait data warehousing?
Dear Sir Marcelo
I want to use SPSS for statistical examination between groups/participants, but some of my data are time series (e.g kinematics and kinetics) which made me confuse about putting them in rows or columnsFollowing
- 1Is there any simple method to analyse an allelochemical in a crop or weed?
We analysed broad group of chemicals such as phenolics, terpenes etc. in the lab. I want to know some method by which we can get an estimate in the field itself.
Tempers include vitamin A,D,E,K you can use for this Amperometric detection.For phenol compounds you can use anion chromatography, HPLC for bigger molecul.Following
- NewIn brief, how do you sustain the students' engagement, enjoyment, happiness and enthusiasm in the design studio?
Teaching Design is not about the final product itself, the process is the key for the experience. the struggle might be physical, mental and sometimes emotional. Sleep deprivation, depression, unconsciousness reflections ...and more.
To sustain the students' envolvement and productivity during all that, the experience must be worth it!
How do you achieve this in your studio? Starting from planning the tasks to the management of the studio itself?Following
- 6Can we insert BIO-sensors inside blood?
I know about edible microchips, but can we develop injectable sensors that insert inside body for detection purposes?
- NewHi, Which grade of polyvinyl alcohol (PVA) is considered as a best surfactant for polymeric nanoparticles?
Waiting for answer.Following
- NewWhy transfiction of Hela cell line is not perfect at all every time, while 293 is usually transficted?
What is the defect behind this relating to Hela strains ?Following
- 6What seminal research articles capture the way in which bureaucratic systems can work against quality mathematics teaching and learning?
I have been looking for seminal articles on how some of the bureaucratic systems of Education, with quality management systems and highly prescribed lesson formats and so forth have constrained possible interventions aimed at increased quality and equity – particularly in mathematics education. I recall many years ago in England that highly structured lesson systems pushed some of the best teachers out. I would love to read further on research that has looked into how bureaucratisation of teachers work can get in the way of the core business of teachers and their focus on student learning.
I know of no specific , but could give no idea where to start these studies
Pleas, keep me informed of the investigation and its results