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

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
  • Hiram Ponce added an answer in Multi Agent System:
    Is it possible to incorporate a Genetic Algorithm within a Multi Agent System (MAS) framework

    I am looking at ways of solving a genetic algorithm such as NSGA-II within the communication framework of a Multi Agent System, i.e, using an Agent based scheme.

    Hiram Ponce · Universidad Panamericana

    Read an IEEE conference article entitled "Genetic Algorithms in a Multi-Agent System". This paper will guide you more properly. Here is the DOI: dx.doi.org/10.1109/IJSIS.1998.685410

  • Danielle Newby added an answer in Machine Learning:
    What should we do to deal with lack of training data in a machine learning task? How about the bagging method?

    I want to work on a machine learning and pattern recognition task but the size of data set is small and there are only 43 samples for both training and testing purpose. How should I deal with this problem? Is there any way to find the reasonable size of data set or it's only based on try and error. 

    Thanks in advanced.

    Danielle Newby · King's College London

    Hi Sajjad,

    As people have mentioned before you have a few options:

    1) cross validation using leave one out, leave many out etc more details in the link below:

    http://en.wikipedia.org/wiki/Cross-validation_(statistics)

    With such a small sample set leave one out cross validation would be the best option here in this section however other methods as shown below..

    2) bootstrapping

    http://en.wikipedia.org/wiki/Bootstrapping_(statistics)

    Someone has already posted this link above however i found this useful link:

    http://www.faqs.org/faqs/ai-faq/neural-nets/part3/section-12.html

    3) Increase sample size - this is a tricky one as this can be done depending on the distribution of your dependent variable in your dataset. You can use for example SMOTE (a type of oversampling technique) however there are other oversampling techniques. As well as already what has been mentioned, semi supervised learning. Finally, other ways to obtain data would be the typical literature search or maybe there is a industry collaborator you can obtain some data from.

    In an ideal situation an external validation set (data that is completely separate from the training of the model) would show the predictability of any model built however when you have such a small dataset doing this would waste vital data therefore the internal validation methods stated in points 1, 2 above are needed. However, be careful as just because the internal validation statistics might be high they too (like the training set) might be over optimistic of the actual model predictive performance. Just something to bear in mind!

    Hope the above helps,

    Danielle

  • Ana I. Estanqueiro added an answer in PMSG:
    What are the advantages and disadvantages of using Induction generators in Direct Drive Wind Energy Converters?

    Most large wind turbine ( above 1 MW) manufacturers use PMSG or EESG with direct drive WEC's. Are there any working models using IG with direct drive systems?

  • How to identify 'parasitism' in practice?

    The definition of parasitism implies that some living beings named 'parasites' take energy for individual survival at costs of living beings named 'hosts'.

    Terminology 'host' might give the impression to 'non-specialists', like tourists, that parasites are always mentally invited to take energy. In addition, humans often give 'energy' (e.g. blood) without knowing the true identity of receivers, thus without having access to perceived costs or benefits involved.

    How to make practically a distinction between 'taking', 'giving' and 'sharing' in Parasitology or Sociology when mental states of actors are ignored?

    Francesca Cansani · University of Applied Sciences and Arts of Southern Switzerland

    Dear Marcel, thank you for your Question.

    I can't direclty answer to it, though, 2 Things or Authors came [Parasites! (I'm jocking)] to my Mind:

    . Roy Martina, who said that when we develop Light [let's say, the Thought of Light, lightful Thoughts] we actually are like Lamps. Have you seen the Lamps during the Night? Not only they attract human Beings who wish to be, let's say, enlightened [and imitate the Example]; they attract Moskitos and Beings like those as well! [...]

    . Corrado Malanga, who has written ''Genesis'' and who is interested in the Phenomena of the so called Abductions. He state that People who have endured an Abduction have probably become the Hosts of certain Parasites [i.E. Aliens, i.E. one called Lux]. It is very interesting indeed!

    Not a very common or well known Theme. According to this Man and his Studies, certain Humans [the Hosts] are the ... Object of Study of ExtraTerrestrial Beings.

    ---

    In both Cases, and many other similar Cases [...], the Question is: what do these Parasites seek? Why do they do want from us? A Benefit, for whom? What do they, let's say, think of us? Do they think of us in a positive Way, or else?

    Generally speaking, the only important Thing is the Host to be innerly good enough, and externally strong enough, to endure the Parasitism.

    ---

    If you ask me, I detest Parasitism.

    Though, better to be a, let's say, Host, than a Parasite, I believe.

    Parasites are, in my Opinion, despicable: there is a Phenomena which has been called, or which is known, Energy Vampirism.

    Certain People manipulate other People, and they take energetically Profit of/from them:

    at a public Level, there are Lobbies which constantly do so toward or against, let's say, Consumers [their, let's say, Slaves].

    We have been taught [sigh] to look at the visible World, while there is a whole, invisible World to be looked at: by the Way, the, so to say, upper Class Manipulators know it very well,

    and they have been working [sigh] at an energetical and invisible Level, since Centuries!

    In this regard, I would repeat what I've said about Parasitism and Parasites, and notably, what I believe about them.

    ---

    When it comes to sublte, quite practical or material, though even somehow invisible and incorporeal Manipulation,

    which is, the psychological Manipulation of People [mental Manipulation],

    the Marketing Strategists do that constantly. In this regard, we All become, let's say ... alienated! We start believing Things [Concept of Beauty, Needs that we allegedly have and which we allegedly want to satisfy, ...] which we actually would never believe,

    and which actually are believed [for us!] by the above mentioned Stategists, and notably, by their Masters [those who ask the Strategists to develop a certain Marketing ... Strategy, in order to serve their own ... Needs, or better Interests].

    We are All, somehow, alienated: we think what Others think or we think the Thoughts, that other People have, let's say, introduced into our, let's say, Heads.

    ---

    Meditations and SelfCentredness might help us to get rid of Others' Thoughts. Though, see above about Roy Martina's Statement [which I rephrased].

    Happiness inside/outside to Every1.

  • Idania Marrero added an answer in Ficoll:
    What is the best way to isolate lymphocytes from murine liver?

    I used to isolate CD4 T cells from spleen and lymph nodes, now I want to isolate T cells from murine liver, do I need to enrich them with a ficoll first or can I isolate them directly using the MACS-System? Or does another method suit better ?

    Idania Marrero · Torrey Pines Institute for Molecular Studies

    Purification lymphocytes from Livers: Remove the liver from the mice and put liver into DMEM/High Glucose medium. Use a small Petri dish to press the liver through 70um strainer, add more medium and centrifuge at 1500 rpm for 6 minutes at RT. Break the pellet and add 15 ml of 35% Percoll in DMEM medium containing heparin. Centrifuge with no brake at 2000 RPM for 15 min at RT. Resuspend pellet in 15 ml tubes with 5-7 ml of red cell lysis buffer, wait 5-7 min and stop with DMEM + 2% FCS. Centrifuge at 1500 rpm for 7 min at RT, wash again and the pellet will be ready to count

  • Dirk Breitkreutz added an answer in Collagenases:
    How do I remove collagens from my collagenase-digested tissue solution when the adipocytes don't settle down?

    I am facing a problem in isolatng adipocytes from rat epididymal fat pads.

    By following the Rodbell method, in which fraction are the adipocytes present? At the last step, after centrifugation of collagenase-digested tissue, the stromal vascular cells settle down, and the rest suspension should have the adipocytes.

    How do I get adipocytes in a concentrated layer in the final result?

    Dirk Breitkreutz · Hochschule Mannheim

    Depending on what you like to do with the adipocytes I have a further suggestion. Though these cells are not very adhesive, you may try plating them on matrix/ECM coated dishes (e.g. collagen type I or IV or BM-laminin) to separate them from lipid vesicles etc. Adipose tissue is surrounded by a basement membrane (BM), so the cells should adhere to respective ECM components.

  • Marcelo Tappin added an answer in Internal Standard:
    Can we normalize the metabolite levels only with cell number, instead of an internal standard for GCMS data analysis?

    I am comparing metabolite levels in different cell lines using gas chromatography mass spec. Although, I add an internal standard in my samples, it's levels are always inconsistent between replicates and if I use it to normalize the metabolite levels, it completely messes with ttest. On the other hand, if I use cell numbers only for the corresponding sample to normalize my data, everything looks fine. The area peaks for the target metabolites in my sample are always consistent between the replicates. I have repeated the experiment 3 times now, with similar results. I know it is recommended to normalize with an internal standard to account for injection errors between samples but does anyone know if cell numbers are a good parameter to normalize the data with? None of the papers describe the detailed data analysis method.

    Marcelo Tappin · Fundação Oswaldo Cruz

    I think you must do both. You are extracting metabolites from a sample of cell culture, since the metabolites are produced by the cells the amount of these metabolites are directly proportional to the amount of cells you use to prepare your sample. In a sense since you can't weight the sample, as I understand,  you have to find another way to quantify the original sample amount, so you can count cells. If you could weight the cells before you extracted the metabolites you would probably find the amount of metabolites to be proportional to the cell weight and you wouldn't have variation between replicates because you would be weighting similar masses. The use of a internal standard is also important to cope with the sources of variations related to the extraction protocol. Concluding I think you should try to normalize the cell  number per sample and then apply an internal standard to control the sources of variation related to the extraction protocol. If you can't normalize the cell number you should, as you are already doing, normalize the metabolites amount by the cell number and then normalize the result by the internal standard.

  • Is the European Union democratic?
    This question is vital for each european citizen. I was one of the two million of signatories of the European Citizens’ Initiative, “One of Us”, which was vetoed by the European Commission illegitimately and anti-democratically.
    (see http://www.europeandignitywatch.org/index.php?id=43&tx_ttnews%5btt_news%5d=443&cHash=d1c5204c3b713d6fbdb9ebbd7ee688f0)
    Alfonso Diestro Fernández · National Distance Education University

    Dear all, 

    I think that the European Union will be truly democratic when the EU belongs to the citizens and not ("only") to the members States. They can easily ignore European initiatives in the cooperation politics areas... Usually, they have never shown sufficient forward-looking vision to go beyond national interests in favour of a greater convergence, such as occurs with common policies. Right now, the austerity's strategy seems to be against civil (and Human) rights in Europe and their welfare state.

    Best regards. 

  • Michael Marcus added an answer in Image Compression:
    What is the definition of image compression?

    I'm confused about two things.

    1. What is the definition of image compression?

    2. Is that okay to say a "compression" is done when the size of an image is decreased by optical means?

    Despite the discrete cosine and wavelet transforms, I wonder if there is another effective optical method for image compression.

    Michael Marcus · Independent Researcher

    There are two types of image compression for data files -- lossless image compression and lossy image compression. Lossless image compression uses compression algorithms which are similar to what is used for the ZIP file format to compress the image data file without losing any of the original image information. There are many techniques for lossy image compression such as JPEG, fourier transform in which the higher image frequencies are removed, reducing the dynamic range of the image, or the use of image companding functions.

    Optically, I can think of several ways to compress an image. The first is to simply make the image smaller such that less detail is recorded across the given field of view of the optical system by a CCD sensor of given pixel size. The second involves either deliberately designing the optical system or adding optical elements to the optical system in order to reduce the modulation transfer function (MTF) of the optical system. Reduction of the MTF can be achieved by losing fine image detail, reducing overall image contrast (dynamic range), or both. Optical methods for reducing the MTF:

    -- Deliberately add or modify an optical element to introduce spherical aberration in order to reduce the overall image resolution and thus the MTF.

    -- Deliberately decenter an optical element or add optical wedges in order to introduce strong astigmatism across the field of view. This is a neat technique if, for example, you want to have excellent resolution across the horizontal image axis yet have poor resolution across the vertical image axis.

    -- Deliberately leave the surfaces of an optical element somewhat rough (not fully polished) in order to reduce the overall resolution of the optical system and thus the MTF.

    -- Deliberately fabricate an optical element which is somewhat cloudy rather than clear. The most effective method is to add an optically flat yet either cloudy or lightly frosted optical element to the front of the optical system. A cloudy optical element would reduce the dynamic range of the optical system. A frosted optical element would reduce both the dynamic range and the resolution of the optical system.

    There are other methods as well. All of the above result in a form of optical image compression by lowering the overall MTF of the optical system. Combinations of the above could also be used.

  • Abdul Razaque added an answer in Cloud Computing:
    What is the major difference between private cloud and public cloud?

    If having private cloud still means having the cost of hardware and software, not to mention the security issues. Is it worth to move to public cloud to save costs?

    Abdul Razaque · University of Bridgeport

    Dear Almaburk,

    This is really very interesting question and i try my best to elaborate the differences.

    The public cloud should have adopt approach (off-premise IT capabilities or applications, provided by others) and private cloud should opt (on-premise enablement of cloud capabilities with existing IT).
    The pro-public crowd has long argued that the ability to consume IT and related services on a pay-per-use model, the speed of access to resources, and the flexibility to add and drop capacity make their approach the only way to go.
    The pro-private camp is quick to remind clients that enabling private cloud capabilities — either on site or in a private hosted environment — provides the highest levels of management visibility, control, security, privacy, and physical data proximity. The peace of mind of knowing exactly where your key business and client data resides at all times


    These are five key factors to consider before deciding whether private cloud or public cloud is the better fit for your company [http://www.networkworld.com].


    1. Budget
    If you run a small business that has a tight budget, you should consider a public cloud provider, because you only pay for what you need. Plus, you probably lack the funds to invest in hardware, software, and staff necessary to set up a private cloud.
    If you're at a large organization with a bigger budget, it might be cheaper to invest in a private cloud than rent a lot of public cloud resources in order to run long-term projects. You will have complete control over security, compliance, hardware, virtual servers, failover algorithms, and Service Level Agreements (SLAs).


    2. Security and compliance
    If your organization has Sarbanes-Oxley Act (SOX), Health Insurance Portability and Accountability Act (HIPAA), and/or Payment Card Industry Data Security Standard (PCI DSS) compliance requirements to meet, you should choose a private cloud to process or store sensitive documents. You know where in the private cloud the documents are when you want them. Also, your organization has certain security controls that a public cloud provider doesn't have.
    The public cloud is more suitable for processing and storing non-sensitive data (you don't care where they are in the cloud). You will likely be satisfied with a public cloud provider's security controls.


    3. Hardware and virtual server control
    Software as a Service (SaaS) users and Platform as a Service (PaaS) developers have no control over hardware and virtual servers; the only control a SaaS user has is to access an SaaS application. PaaS developers have control over the SaaS application life cycle; they decide what stress testing methodology to use and what operating system to run on the platform. Only the provider has the control over hardware and virtual servers.
    If your organization wants complete control over hardware and virtual servers, you should consider a private cloud. If your budget is limited, I recommend looking for a public cloud provider. You can rent a SaaS application or develop simple applications on the PaaS of your choice.


    4. Failover control
    If you choose to set up a private cloud, you will have complete control over a failover plan to ensure the cloud service will be available to users. You specify which healthy servers can automatically take over when a server's connection fails, or when the server experiences sudden loading spikes. You can test your failover algorithms in different scenarios to make sure they will work properly when a server begins to fail.
    A public cloud provider has complete control over a failover plan -- the provider doesn't share its proprietary failover algorithms with you. The public cloud is the right choice if you don't care about the location of any server or which healthy servers would take over.


    5. SLA management
    A private cloud helps an organization have complete control over SLA management. Your business can see how direct and indirect SLAs are related and what metrics are used in each SLA to measure service availability at given points of time.
    A public cloud provider has control over SLAs with all tenants. As a public cloud subscriber, your organization should be allowed limited negotiation on the terms in a SLA, including an exit clause. The provider will not let you view SLAs it has with other tenants and vendors.
    Conclusion
    If you have sufficient funds, have compliance requirements to meet, and want complete control over security, hardware, failover, and SLA management, a private cloud is your best bet. Otherwise, I advise you to opt for a public cloud provider.

  • Francesc Casanellas added an answer in Capacitor:
    What is a suitable filter for a tyristor rectifier?

    We have a battery smart charger and discharger that produces a very harmonic grid.

    We use the capacitor bank but after few time the capacitor fails. 

    Can anybody help me with a design filter?

    Francesc Casanellas · ALP, S.C.

    You have to use polypropylene capacitors. Other capacitors will fail with high di/dt.

    And as John Brindle says, a small input choke will help.

  • Bryan W. Reed added an answer in Scattering:
    How small is a small angle in the TEM and why are scattering angles in the TEM usually this small?

    How small is a small angle in the TEM and why are scattering angles in the TEM usually this small?

    Bryan W. Reed · Integrated Dynamic Electron Solutions, Inc.

    The Born approximation (basic quantum mechanical model for scattering theory) as well as the more elementary Bragg picture of diffraction both tell you that a typical angle for a single scattering event is roughly equal to the wavelength (which is essentially the same thing as the inverse momentum) of the radiation divided by the length scale of the thing it's scattering off. So for a 100-300 kV electron with a wavelength of a few pm scattering off an atomic-scale thing with typical periodicity of a few hundred pm, a typical scattering angle ends up being ~0.01 radian.

    The exception is when it scatters off something much smaller, such as an atomic nucleus, which means it has to get close enough to the nucleus for Rutherford scattering to be dominant. Then, in one of the more curious examples of the correspondence principle, the classical formula for the angular distribution applies. So this tells you that, mixed up with the ~0.01-radian scattering events that involve the atomic-scale structure, you'll have rare high-angle scattering events all the way up to 180 degrees.

    Which is exactly what you observe. Multiple scattering and inelastic scattering complicate the story a bit, but this basic semiquantitative picture is still a good way of thinking about it.

  • A. G. Piyal Aravinna added an answer in Syringes:
    What kind of cleaning procedures should be performed (column, syringe from the auto-sampler) when analyzing phages in HPLC?

    Good afternoon, 

    I will appreciate any comments on cleaning procedures after analyzing bacteriophage on an HPLC system.

    The columns we will be using is a LiChrosorb RP-18 and an Acclaim C30 with a mobile phase of A: KH2PO4 (0.05M, pH = 6) and B: MeOH 100% and (A:B; 90:10), flow: 0.6mL/min, temp.: 10C.

    thanks a lot for your help

    Anelore

    A. G. Piyal Aravinna · Central Engineering Consultancy Bureau


    Dear Anne-Laure Chauvin


    You are using reverse phase C18 column. Passing strong acids of base through the system is not suitable for the column and compartments.

    You have used KH2PO4 bffer solution for your analysis. So, first, you have to remove ionic buffer. To do this, you have to pass aqous mobilphase 80% water (in Methanol or acetonitrile) for two three hours (or till stabilize the baseline).


    As second step, you have to remove the organic commpound retaining in the column. To do this, you have to pass water : acetonitrile mixture (from 80:20 to 20:80)for one hour.


    If you dont have Actonitrile you can use methanol.


    Piyal

  • Hafeez Mohammed added an answer in Concrete:
    I am working with Ultra High performance concrete using locally available materials how does the sand gradation effect the mechanical properties??

    Concrete experts 

    Hafeez Mohammed · University of Akron

    Agree but you cannot use the bigger gravel for ultra high performance concrete they are undesirable bigger the size weakest the link, when comes to ultra high performance concrete the patented products use pure silica sand which is not only very clean but also absorbs less water leaving water for good matrix, but silica sand is very expensive so use of graded natural sand can work if we grade them properly. People have used the partial replacement of sand with no 8 gravel but couldn't achieve higher strength as you get without no 8 gravel 

  • Is there any viable and innovative solution for the world’s food crisis and food-shortage problems?

    The earth’s population may grow by three billion in the next 50 years or so. The world’s ever-growing number of people points toward a greater demand for food in spite of the already-scarce resources. Famine, hunger and starvation are accordingly a major issue in poor countries worldwide! In your opinion, would the world’s food production/industry suffice to feed the hungry stomachs (given the land and water limitations/scarcity)? What are the world’s options in this respect?

    Thanks so much for your contribution!

  • Are research projects proposed for financial support often too ambitious?

    There is a lot of competition to get financial support for research activities. Can this result in the presentation of research projects that are over-ambitious, also accepting that scientific results that result from such projects cannot be predicted with high certainty?  

    Marcel M. Lambrechts · Centre d'Ecologie Fonctionnelle et Evolutive, Montpellier, France

    Thanks Mohammad,

    I will buy this one! I have Jim Baggott. 2012. Higgs. The Invention and Discovery of the 'God Particle'. Oxford University Press (Dutch translation)

  • Jingyi Liu added an answer in Akt:
    How could I get a sharp band when doing WB?

    I've done Western Blotting using total Akt, pAkt ser 473 and pAkt thr 308. For total Akt and pAkt ser 473, I mostly see a very clear and sharp band. But there are so many non-specific bands for pAkt thr 308. All of the conditions are the same. I use 5% non-fat milk to block and 5% BSA to dilute the primary antibody. 

    Thank you!

    Jingyi Liu · University of Michigan

    Thanks! We use the cell signaling antibody. I do run separate gels. I've never stripped the membrane. I can see that they are at similar sizes but there are just too many non-specific bands for thr 308. 

  • Can we consider the positive reactors to skin sensitivity to histoplasmin as persons exposed to Histoplasma capsulatum present in their locality?

    Positive skin reaction to histoplasmin was detected in 9.4 per cent and doubtful reaction in 13.8 per cent of 275 persons tested for histoplasmin skin sensitivity in West Bengal. Most of the histoplasmosis cases reported  from India are from West Bengal. With isolation of Histoplasma capsulatum from local soil and positive reactors to histoplasmin in the local people, the endemicity of histoplasmosis in India is established.

    Roseli Santos Freitas · Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo

    Yes, according to the exposure time, amount of inhaled fungal propagules, it is important to emphasize that this is an endemic area that the agent was isolated from the environment. There is a note on preliminare inter-reaction of skin test sensitivity between histoplasmin and Chrisosporin in experimental animals. Fungus has in its composition of cell wall carbohydrates that can generate cross-reactivity, so the relevance of isolation of Histoplasma local soil demonstrated to be autochthonous.

  • James F Peters added an answer in Software:
    Is there a software that does log or division with accuracy up to one million digits?

    See above.

    James F Peters · University of Manitoba

    In addition to the answers already given, especially @Saheya Saheya and @Mariano Pierantozzi, try the following script in either Mathematica 9 or Mathematica 10:

    N[log[pi]];

    Accuracy[%]

    The accuracy returned is infinity (unbounded).

  • Diego Venturelli added an answer in Animal Behavior:
    Which is the best free software for animal video tracking and behavioral studies of captive fish?
    I'm running some behavioral trials on captive fish, like open field test, mirror test and novel object test. I'd like to analyse the data using video tracking software to get information about fish activity, area used, proximity to an object, etc. I'd appreciate any suggestion of a free software that helps me with this task, e.g., by providing me the coordinates of the fish track over the time. Thanks.
    Diego Venturelli · University of São Paulo

    http://www.noldus.com/animal-behavior-research

  • Barry Turner added an answer in Philosophy:
    Can ethics be measured objectively?
    Ethics, ethical committee, ethical approval and other ethical related words are extensively used on Researchgate and other places. How to define and measure ethics in objective bases?
    Barry Turner · University of Lincoln

    I am not sure that ethics and beauty (aesthetics) can be conflated.  Granted they do have in common a profound difficulty is 'measurement' and a massive degree of subjectivity but that is not a problem per se.  

    Bruneleschi's Santa Maria Del Fiore is subjectively beautiful but some paintings while profoundly disturbing are also aesthetically gripping.  Bosch's Garden of Earthly Delights is both beautiful and deeply disturbing.  The two states are not mutually exclusive.

    Some questions do not have definitive answers and Ahed's is one of them.  In any case does it actually matter whether ethics can be measured or not?  Are we any better for ethics being a 'science'?  Why is subjectivity automatically looked upon with suspicion?

    To some a Samurai sword or a B52 bomber are graceful and beautiful, Their shape and design are certainly iconic, the skill in their creation staggering.  We can appreciate the grace and style of a form even if its purpose is destructive.  The same goes for ethics.  Larry mentioned the ethics of the Spartans an example of extremes if ever there was one.  We would be appalled by a modern society acting as they did but still we admire some of their characteristics and salute their courage.

    We cannot measure the uncertain or the variable.  Times change and ethics with them.  in 1789 the right to bear arms as a part of a properly constituted militia was undoubtedly an ethical position to hold.  In 2014 the assertion of that anachronistic right causes immeasurable suffering and heartbreak.  Most today would hold that the right to self determination is an ethical position to defend.  Few however would support a states right to self determination that was expressed in the form of maintaining slavery.

    As I mentioned before, at what point in that timescale do we apply the 'ethical micrometer'.  Would the ethics we value above others today be just as valid tomorrow. 

  • What are some new recycling strategies for the disposal of urban waste?

    Recycling technologies for the processing of urban waste are being continuously improved.

    Currently, more than 30% of MSW generated in the United States is recycled annually. The United States has about 872 operational MSW-fired power generation plants, generating approximately 2500MW, or about 0.3% of total national power generation.

    However, because construction costs of new plants have increased, economic factors have limited new construction.

    Lala Behari Sukla · Council of Scientific and Industrial Research (CSIR), New Delhi

    Australians generate more than 140,000 tonnes of electronic waste (e-waste) each year and most of it ends up in landfill. As well as putting more pressure on limited landfill capacity, e-waste can be hazardous as it contains toxic materials.
    To keep recyclable e-waste out of landfill, the City of Sydney offers free quarterly drop-off days.

  • Has anyone know the normal value of normal TOTAL BILIRUBIN in male Wistar rat?

    I look for an old paper from Muraca 1987 Gastroenterology 92, 309-317 "Relationships between serum bilirubins and production and conjugation of bilirubin. Studies in Gilbert's syndrome, Crigler-Najjar disease, hemolytic disorders, and rat models." (with reference literature) rats. (OR) I need normal data to compare data of control animals in our labs. Blood sample was taken from tail vein and plasma total bilirubin was measured by a cold chemistry photometer. Thank you

         
    Andrey Borodach · Novosibirsk State Medical University

    It is reported as 0.42 mg/dL, but this is a just mean value that can vary. 

  • How can i perform T-test in spss for comparing means of two groups with different sample size.?

    I want to compare means for management barriers/items obtained from responses in two countries for cross-cultural comparison.. But the sample size is 180 for one group and 60 for another group..

    Angel Dzhambov · Medical University of Plovdiv

    You can just perform Welch's t-test which does not assume homogeneity of variance or equal sample sizes. Take a look at this: https://www.youtube.com/watch?v=fl6wgE4Edqw&list=UUr3OHuCSrwAO2KYP2CJB6zg&index=29

  • K. K. Sinha added an answer in Gamma Rays:
    Does anyone have suggestions for specific units to do measurements of gamma rays on outcrops using commercially available portable devices?

    I am interested in mapping outcrops for gamma radiation.

    I see that there are a number of commercially available units, but I sense that the field is rapidly changing and advancing. Thus, I am looking to hear from people with direct experiences using these units in the field to assess rocks.

    K. K. Sinha · Atomic Minerals Directorate for Exploration and Research

    Different portable devices for gamma ray measurement used in field are calibrated for different unit.Portable scintillometer generally gives output in micro-Rontgen per hour, Gieger Muller couter in count per second and presently available portable gamma ray spectrometres in ppm.  For lithological mapping, I would suggest to use portable gamma ray spectrometres which is capable to give you uranim, thorium and potassium values in ppm.

  • What approaches can be used while measuring an effect of an event on a stock price of a company?

    In order to measure the effect of an event on a stock price (of a company), one approach would be to take into account the "information asymmetry". When an event occurs on a particular market it might have a straightforward impact on the companies located in that market and also impact on companies located elsewhere but having relationship with that market. This is one approach. I am looking for other different approaches, standpoints and etc. that can help me examine the effect of an event on a stock price.

    Riste Ichev · Universiteit Utrecht

    Thank you very much. I will think about this ..

  • Debosree Pal asked a question in Embryonic Stem Cell:
    Can anyone share with me a protocol for the differentiation of mouse embryonic stem cells into primordial germ cells?

    Hi,

    I am looking for a protocol to differentiate mouse embryonic stem cells into primordial germ cells. Can anyone provide me with a convenient protocol? How long can the differentiated cells be propagated and is it a suitable model system for manipulation like knockdowns?

  • Does anybody have any resources on mobile radiography?

    Hi,

    I would appreciate any suggestions for resources on mobile radiography.

    For example, the use of mobile X-ray units, including status, advantages and disadvantages.

    Thank you in advance,

    Albertina.

    Carla McCaghren Allen · University of Missouri

    Hi, Albertina,

    What an interesting thought! I find international comparisons of imaging practice fascinating. Here in the central US, we have several companies that provide mobile radiography to care centers and retirement homes. Several of our recent grads are working for these companies. In the past, they were film-screen based imaging and the image quality (at least around here) was often poor because the technologist had to drive an hour or two to develop the image and didn't know if they had made positioning mistakes until they were well away from the patient. All of the companies in this area have adopted CR systems that have photostimulable phosphor plate readers in their cars and are connected to PACS systems by cell. The physicians offices and other centers use standard radiographic rooms when they offer imaging services (although I do know of a couple of places with a

    Your question also tugged at a memory from my past. One of the radiologists that I have worked with did studies using hand held x-ray units (typically designed for dental use) in combat situations. It may not be of interest, but just in case, I am attaching a RIS file of the articles that you can upload to Zotero or Endnote or whatever citation tool you use.

    Carla

  • Adnan Iftikhar added an answer in HFSS:
    Can anyone tell me how I can simulate a receiver in HFSS with farfield source?

    I would like to simulate a phased array of patch antennas in receiving mode with a far field source in HFSS. I don't know how I get the field components or the voltage signal at the end of each antenna. Please help me! Thank you.

    Adnan Iftikhar · North Dakota State University

    @Nhat...Yeah you can simulate any antenna is receiving mode with far field source. Excite your receiving model (lump port/wave port) and then right click on Field overlays in Project manager and go to edit source option and change the solved magnitude to 0W (in wave port case) and 0V (in lump port case) for the excitation of receiving antenna. In this manner your antenna will simulate in receiving mode. 
  • Does anyone know a dataset of sunshine duration for the whole Europe?

    Hi everyone,

    I would like to use monthly or daily time series of sunshine duration or any other product related to the surface incoming radiation for the modelling of vegetation phenology (spring onset). 2002-2011.

    As far as I know there is a dataset of sunshine duration from WMO Regional climate Centre on climate monitoring (www.dwd.de/rcc-cm). However, this dataset is interpolated from a limited number of ground stations. I was wondering if there exist others datasets retrieved from satellite imagery  (i.e. SEVIRI) or both satellite+stations.

    Thanks