Q&A

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.

#### Browse Topics

• What is the next in coronary artery disease prevention?

The essential logic is to decrease the time of exposure to cardiovascular risk factors with genetic insights providing strong justification for this approach. Lifetime exposure to lower concentrations of cholesterol specifically, plasma levels of low-density lipoprotein (LDL) cholesterol, is shown to be associated with larger reduction in the risk of coronary heart disease. The decrease in risk is related to the genetic variants of receptors that remove cholesterol from the circulation matched with individuals who do not carry such variants. For a known reduction in LDL cholesterol, there was much more impact on reduction in cardiovascular disease risk than that reached with pharmacotherapeutic modulation in late life. Several studies have shown that the adoption of a healthy life , the act of not smoking, weight control and perform regular physical activity , with the reduction of cholesterol levels can be more effective than drug therapy of known effectiveness. How best to link these two strategies and show people that the protection of their coronary health goes beyond the use of drugs ?

Does anyone know how to prove that this real integral is non negative?

I would like to prove that the following real integral

$$I_t(x)=\int_{-\infty}^{\infty}e^{-\frac{\cosh^2(u)}{2x}}\,e^{-\frac{u^2}{2 t}}\,\cos\left(\frac{\pi\,u}{2t }\right)\,\cosh(u)\,du$$

(with x,t>0 ) is non negative, that is, $I_t(x)\geq 0$. The main problem appear with the oscillatory term

\cos\left(\frac{\pi\,u}{2t }\right)

Gabriel Mititelu · University of Western Sydney

Pedro, give a try by using the attached integral identity and split the interval \left[ {\frac{\pi }{2}, + \infty }\right) into parts where sin(x) is positive or negative, from there do the analysis of positivity on each subinterval following Ian's approach....cheers

• Dominique Bachelet asked a question in Python:
Does anyone know of a good carbon model in python?

We have a model in C++, C and good old fortran. We are trying to update, upgrade, improve all the algorithms. we have chosen python as a language to write the new model. Any building block available? We will look at the C cycle and at fires.

• Does the level of Emotional Intelligence differ according to the Company Sector?

I am writing my FMP about Emotional Intelligence in the Business World. I will be carrying out a study to see if there are differences in the level of EI depending on the Company Sector, with a special focus in the Fashion Sector.

Data Collection through: Surveys, Semi-Structured Interviews, Online Focus Groups, and Participant Observation. With the aim of analysing how an individual is in terms of his emotional capabilities and skills by answering a certain sequence of questions about himself and about his working environment. I designed these questions according to the definition of EI and its components so that I could measure his: self-control, self-awareness, self-motivation, empathy,and, interpersonal relational skills. (Everything individually)

Then by filtering my results into which company sector this person is in I would be able to see if there are any differences or not among them.

Rojan Baniya · Kathmandu University School of Management

Hi Ana,

Agreeing with Ariel's comment, may you need to re-frame your research as - is the requirement of EI different in different industry? Certainly in service industry where frontline staff are of great value EI plays critical role. Maybe for manufacturing industry, it is not that important. EI is not organisational trait, it is an individual capability. Just recently I presented a paper on conference as how perceived organisational politics affects the relationship between EI and other outcomes. My finding shows EI normally have positive relationship with organisational outcomes. So please think about your research question.

Best

Rojan

Are these Taeniidae eggs found in feces from Neotropical Otter (Lontra longicaudis)?

These eggs were found in feces from Neotropical Otter (Lontra longicaudis)

Scott Lyell Gardner · University of Nebraska at Lincoln

I agree with Dan about the ascarid egg.

Which LPS would you consider "most typical" and suitable for testing in human and murine cells?

Hello,

I am interested in testing the various effects of LPS in in vitro models of human (immortalized cell line) liver and mouse liver cells.

I want to use an LPS that is enterobacterial and "structurally typical" in relation to TLR4 response. Which of the following LPS would you think most relevant:

(1) Salmonella minnesota

(2) Salmonella typhimurium

(3) Salmonella Typhi

I am not considering using E. coli LPS. Thank you very much for your comments.

Divaker Choubey · University of Cincinnati

I agree with the comments above. In our hands, LPS from different sources works differently in THP-1 cells. Therefore, it is important to first determine whether cells do or do not express detectable levels of TLR4 before trying LPS from different sources.

Can I run a sample on an agarose gel, refrigerate it, and run it again at another time?

Something I've always wondered about- if I'm running a electrophoresis agarose gel and something comes up and I cannot finish it, is it possible to refrigerate it as per usual, take it out of the fridge, and continue running it at a later time?

Dejun Li · Chinese Academy of Tropical Agricultural Sciences

Yes, you'd better wrap your gel with preservative film and put it in refrigerate. When you have time to work again, you remove the preservative film and restart your experiment.

• Robert Shuler asked a question in Pedagogics:
What is the path of a horizontal light ray in a sheet metric?

Using the geodesic method, what is an expression for the light path, and the falling path of a mass, or at least the vertical (x) position of each as a function of time, with the light initially horizontal?  The "a" is the field acceleration.  If results are interesting, a pedagogical paper may be considered.

ds2=-(1-ax/c2)2c2dt2 + (1-ax/c2)-2dx2 + dy2 + dz2

• Which is the best way to track down neurogenesis spatiotemporally in my samples?

i would like to know the best way to track down neurogenesis spatiotemporally in my samples, please suggest the best method? which is the best method?

What is the reliability measure equivalent to Cronbach alpha for a computer adaptive test?

We use Cronbach alpha for non-adaptive test to check internal consistency of items measuring the same construct. What is the equivalent of this for an adaptive test?

Naoko Taguchi · Carnegie Mellon University

Thanks for the information!

• Can you indicate, research papers, thesis, data sets or similar about socio-economic profile of pre-service teachers in your country?

In Brazil the majority of pre-service teachers are from low income families, have illiterate parents and the average of age is a little elevated (30,2 years to be more exactly).

Daniel de Freitas Nunes · University of Brasília

Marković G. Đoko,

So, the situation in Brazil is not too different of europe... Anyway, do you have any paper, thesis or similar that you can indicate me about this issue?

• What are your thoughts on using Biological control as a countermeasure against invasive alien plants?

The "enemy release hypothesis" is an often documented mechanism by which alien plants become invasive. There are opinions of using native enemies (may be modified) against these weeds in invaded ranges? Are there examples where such control strategies have worked? And is there any future for the approach

Jonatan Rodríguez · University of Vigo

Hi Nelson, I think that 's a good question for discussion.

In my oppinion, I believe that it is necessary to know a lot more about this field. We need go out and see what is happening in the ecosystems. Probably, with the time, some herbivory insect (New natural enemies on non-native range) could be adapted to alien plant species and they can changing their ecological behavior in the presence of this invasive plant. In last months, I saw some interesting things about this fact. On the other hand, I believe that using exotic natural enemies or probably modified, could be a serious problem.

Philosophy and Science, what is the connection?
The connection between science and philosophy has endured for thousands of years. In present-day conditions it has not only been preserved but is also growing substantially stronger. The scale of the scientific work and the social significance of research have acquired huge proportions. For example, philosophy and physics were at first organically interconnected, particularly in the work of Galileo, Descartes, Kepler, Newton, Lomonosov, Mendeleyev and Einstein, and generally in the work of all scientists with a broad outlook.

At one time it was commonly held that philosophy was the science of sciences, their supreme ruler. Today physics is regarded as the queen of sciences. Both views contain a certain measure of truth. Physics with its tradition, the specific objects of study and vast range of exact methods of observation and experiment exerts an exceptionally fruitful influence on all or nearly all spheres of knowledge.
Philosophy may be called the "science of sciences" probably in the sense that it is, in effect, the self-awareness of the sciences and the source from which all the sciences draw their world-view and methodological principles, which in the course of centuries have been honed down into concise forms.

As a whole, philosophy and the sciences are equal partners assisting creative thought in its explorations to attain generalising truth. Philosophy does not replace the specialised sciences and does not command them, but it does arm them with general principles of theoretical thinking, with a method of cognition and world-view. In this sense scientific philosophy legitimately holds one of the key positions in the system of the sciences.

http://www.marxists.org/reference/archive/spirkin/works/dialectical-materialism/ch01-s04.html

Can philosophy develop by itself, without the support of science? Can science "work" without philosophy? Has science reached such a level of theoretical thought that it no longer needs philosophy? Or is the connection between philosophy and science so mutual that it is characterised by their ever deepening interaction?

I all descend from  human engineering and accounting high scale activiities that were necessary for the first agriculture based civilisations.  Gradually we separated these activities into specialized activities.  The reasons they all fit so well even today after thousand years of separation is that they are all rooted in human activities.

Is it time we shift emphasis from technological solutions to climate change & focus on the 'Human Dimension'?

Is it not obvious that nature can heal itself, if only left alone? Many natural parks managers do just that; seal off the area from human interference to let nature heal and recover. It is classified as 'Strict Nature Reserve"by IUCN. Complacency is not advocated here, as many have misunderstood, but the shifting of focus from technology to the human being. As technology is no match for human greed, isn't introspection & restraining ourselves more relevant than developing more technology, which caused the mess in the first place, by making it easy for a few to consume more? Since technology is only a short term quickfix which fails after a short time, isn't the real problem our addiction to material consumption & our lack of understanding about human nature? Isn't developing more technology sustaining the addiction instead of correcting it, leading to more complex problems later on, needing more complex technological quickfixes like higher drug dosages, more ground troops & equipment, (along with their debilitating side effects) in the future? Isn't this the vicious addiction circle we are trapped in? As researchers, do we merely buy more time with technology OR go to the very root of the problem, the human being?

A lot of hue and cry is made about climate change and the environment in general. Public and private money is poured into research to study its effects on the environment, sustainability etc. Should we study nature or ourselves?

" Our studies must begin with our selves and not with the heavens. "-Ouspensky

Human activities have been found to have a direct correlation to climate change and its impact on the environment(I=P x A x T, the Ehrlich and Holdren equation), in spite of what some complacent sections say to protect their own self interests.

We hardly know about Human nature. We can scarcely predict human behavior. We need to find out why we think like we do and why we do what we do and why, in spite of all knowledge and wisdom, consume more than what we need, in the form of addictions to consumption and imbalance not only ourselves but also the family, society and environment around us..
Humanity is directly responsible for all the unnatural imbalances occurring on the planet. Yet we refuse to take responsibility and instead focus on climate change, or fool the public exchequer with a 'breakthrough in renewable energy just around the corner'. We scarcely know what drives human beings. If we had known, all the imbalances around us would have had solutions by now, given the amount of money plowed into finding such solutions. Are we blindly groping in the dark of climate change because we don't know the answers to our own nature?
Is it not high time we focus on what makes us human, correct our consumptive behavior and leave nature to take care of climate change? Why focus effort on 'externals' when the problem is 'internal'- 'me'?
Aren't we addicts denying our addiction and blaming everything else but ourselves?

" We are what we Think.

All that we are arises with our thoughts.

With our thoughts, we make the world." - Buddha

IMHO, We don't need to save the World. It is enough if we save ourselves from ourselves. The need of the hour is not vain glorious interventions, but self-restraint and self-correction!

The Mind is the Final frontier.

Dean von Germeten · Arcanum Industries

Mr. M.P. Weinstein;

You are talking about coming between a crocodile and its dinner.

What are the traditional methods to cure skin pigmentation problems?

If someone has black pigments on their body parts then what herbal medicine or traditional method can be used to remove /cure such pigmentation?

I also read somewhere a paper on Aloe vera reducing dark pigmentation but I agree with the others, check the spot first. Rule out sinister possibilities.

• Jasim Alaly asked a question in Indexes:
How can I measure The Economic Openness ?

I am trying to find the exactly index for Economic Openness , but what I found untill now is just the Trade Openness Index !!!

• Jane Lindborg asked a question in IgG:
How can I reduce the binding of a mouse secondary to IgGs on mouse tissue?

I tried incubating the mouse tissue with an unconjugated IgG (for 2 hours) prior to adding the mouse secondary, but I still get a lot of background. Is there a way to reduce the background without using a MOM kit?

What method (or which device) is commonly used in inpatient and outpatient clinics for wound area measurement?
Wound area reduction is a good predictor of wound closure, therefore the question is which method of wound area measurement is suitable and which is not.
Roy M Kimble · Lady Cilento Children's Hospital, Brisbane, University of Queensland & Queensland University of Technology

We used to use the Visitrak system, but has the disadvantage of having to trace over the wound.

• Can any one help me regarding current mode control of dc dc Boost converter?

Hello all,

I am working on dc dc converters for which I want to design a boost converter in current mode control, can any one help me regarding Matlab simulation and modeling?

Muhammad Wasif Umar · Universiti Teknologi PETRONAS

Dear Luis,

Thank u for ur kind response, I will try and if I hav any difficulty then I will ask again. Actually I am trying to make constant dc current source using Switch mode power supplies for which I am using current mode control Boost converter. If u know any thing abt constant dc current source kindly do let me know.

Regards

• Which environment science, aquatic ecology publications have a clear evidence of merit?

It is useful to know this.

• What is meant by non local hidden variables?

Sir Einstein was the first involved in these type of variables, but why we need such variables and what is their physical meaning?

Sofia D. Wechsler · Technion - Israel Institute of Technology

Dear Gyan, Alhun and Stefano,

Bohmian mechanics doesn't provide a general definition of nonlocal hidden variables, neither Leggett. Given an entanglement of 2 particles,

|Ψ> = α|a1>|b2> + β|a1>|b2> +  γ|a2>|b1> + δ|a2>|b2>,

where a1 , a2 , are eigenvalues of a binary operator A of one particle, and b1 , b2 , are eigenvalues of a binary operator B of the other particle, the general definition of a non-local hidden variable Λ is that it produces the following effect: the result of the measurement of A and B is a vector function V(A, B, Λ) with values V(A, B, λ1) = (a1, b1), V(A, B, λ2) = (a1, b2), V(A, B, λ3) = (a2, b1), V(A, B, λ4) = (a2, b2). Here λ1 is a set of values of Λ of measure |α|2 , λ2 is a set of values of Λ of measure |β|2, and so on, where the four sets are disjoint.

Well, despite all the wording above, I didn't say much: nobody knows what are these nonlocal variables, how they are implemented. To keep under control two particles distant from one another, and measured so that a photon transmitted during one measurement doesn't have enough time to reach the other site during the measurement there, nobody knows how can be done. Some people speak of faster-than-light signals, but it can be easily shown that such signals are a self-contradiction.

• Jane Lindborg asked a question in Trizol:
What is the best way to extract RNA from mouse sciatic nerves?

I've been using trizol to homogenize frozen nerves. I've pooled 2, 4, and 6 nerves and ran qPCR for GAPDH. The Ct values for all combinations were about the same (~23). So I used 2 nerves to run a data set, but this time my Ct values for GAPDH ranged from 26 to 31. I think I may just not have any RNA, and the readout of the RNA concentrations is something else. What protocols have worked for others?

Can someone advise on Pyeloplasty or Nephrectomy in a neonate having UPJO with SRF 5%?
What would be the practice in a 4 weeks child with antenatally detected unilateral HDN with PUJO when the SRF is only 5%? Pyeloplasty, PCN followed by Pyeloplasty or nephrectomy?
Most of the poorly functioning UPJO kidneys show improvement in function and not all such kidneys should be removed without a trial of PCN.
[Gupta DK, Chandrasekharam VV, Srinivas M, Bajpai M. Percutaneous nephrostomy
in children with ureteropelvic junction obstruction and poor renal function.
Urology. 2001 Mar;57(3):547-50.]
Roy M Kimble · Lady Cilento Children's Hospital, Brisbane, University of Queensland & Queensland University of Technology

Can't expect much from a 5% kidney. Will be asymptomatic, so why not wait and watch.

Is tray dryer the best for grains, especially maize?

Design and fabrication of a dryer for maize on corn cobs.

Shanker Lal Shrivastava · IIT Kharagpur

What is the material being analyzed?

Where can I find a dataset of melanoma images?

Eliezer Soares Flores · Universidade Federal do Rio Grande do Sul

I fill-in Mr. Baraka Maiseli, but unfortunately the link is not working...

• Which full texts of recommended environmental science papers were made available online free recently?

It is useful to have this information.

Can anyone suggest me survey questionnaires to measure the knowledge of the harmful effect of Smokeless tobacco use, Age Group (13-15)?

I am conducting a survey in the schools (13-15) to see the current prevalence of smokeless tobacco use and explore how much they know about the harmful effect of its use. In addition I am also trying to explore how much they know about the Oral Cancer and Oral Leukoplakia which is related to smokeless tobacco use. Thank you.

md Ullah · Anglia Ruskin University

Thank you Mohammed and Robert !!!!

• When it comes to simultaneity is Einstein correct or is Dingle correct?

Albert Einstein claimed in 1905 that a single event can occur simultaneously at different times within two inertial reference frames moving relative to one another. In 1950 Herbert Dingle argued that different times cannot be simultaneous. I have analysed this conflict by deriving the Lorentz equations using both points of view. According to this analysis Dingle must be correct. See youtube presentation of this analysis at  https://youtu.be/4XLYzhHQ64Y

Erkki J. Brändas · Uppsala University

Charles,

Actually you need 5, see below. I have said this in three other threads and I repeat for the second time in this thread. Here the are the axioms:

I. The velocity of light is the same in all privileged systems in uniform motion with respect to each other

II. The properties of space and time, which consists of the following four well-known axioms, i.e. a) Space and time are homogeneous.  b) Space is isotropic. c) Space is symmetric with respect to velocities. d) The superposition of two positive velocities will again be a positive velocity.

I did also enclose a scanned pdf file that demonstrates in detail how these assumptions unambiguously lead to LT and the Doppler effect. Note that the derivation does not make use of Maxwell’s equations. Furthermore axiom IId) shows the necessity of a maximum velocity!

Since Valentin erroneously pointed out that this argument is self-proclamation, I state again that these axioms were discussed by Pauli and others and were collected in a more recent study (Löwdin, 1939, 1998), from his book “Some Comments on the Foundations of Physics.

In passing Valentin’s comments are not only insulting, it is moreover reflexive in that the nitpickers, we are debating, do nothing else than pointing out their own results – in stark contrast to the defenders of deductive science.

Valentin – I am curious that a clever fellow like you do not see the irony in your own statement.

I am also surprised that Stam does not realize that his accurate and logical defence of STR and GR is meaningless since the revolutionaries do not care to tell that they have already done away with the first postulate.

• How can we quantify the benefits of proposed transit facilities to CBDs (central business districts)?
There's a growing body of research relating transport infrastructure (particularly transit) to land values, mostly in suburban situations. But how can we identify and quantify the potential benefits of proposed transit facilities to CBDs and the inner city?

Most transit facilities don't stack up in traditional benefit:cost analyses, but may afford great benefits in amenity, livability and the socio-economic wellbeing of our city centres. How can we evaluate those benefits and include them in the benefit:cost equation? Or, if we are stuck with some sort of MCA, what measures are available to allocate scores to such benefits in such a way that they can be weighed against implementation costs?

The same question applies also to active transport infrastructure.
Shian-Loong Bernard Lew · Taylor's University

Perhaps to look at the network effects (Metcalfe's Law) arising out of such a proposal-focusing on the total value of the existing network of accessibility if new nodes and links are added. There are a number of forums/blogs which might provide further insights...