Reddit mentions: The best bioengineering books

Dacron I am sorry to hear that but there is more to it. Exciting changes have happened in the last 2 years regarding biotechnology but following the trend of exponential tech this will only get better. Like everything else in this world, a title is not enough. Biotechnology is just one variable in the equation of an exciting outcome. You need CREATIVITY + PERSISTENCE and a well defined goal of what you want to achieve. Someone with biotech background can innovate on new therapies for diabetes, htn, hld, heart failure. ETC. I started reading a book on biodesign. Please recommend this to your friend and hopefully he can see the true potential of biotech. http://www.amazon.com/Biodesign-Process-Innovating-Medical-Technologies/dp/0521517427 If he feels down and is a redditor, tell him to contact me, maybe I can help him get his inspiration back.

Yeah Einstein, that's why some of the folks I'm relating to won Nobel Prizes and you are academically jerking off typing here on Reddit et al.! Btw. even your own "Debunking" table that you posted shows China as Nr. 6 on IQ and only 1,374 $ income, just as I mentioned before and the other high income countries accordingly. Studies vary slightly but even yours proves again the high correlation between higher IQ x higher income. And regarding Israel and the topic of ethnicity among them read below.

ASHKENAZI  JEWS**: Unlike the “average” Jew in Israel whose IQ is given above as 94, the Ashkenazi Jew is said to have an average IQ of 110-115, sometimes as high as 117. This is 10 points above the Hong Kong Chinese (107), 20 points above the Canadians (97), 30 points above the Mexicans (87), and 50 points above the Nigerians (67).

>“The 2005 paper “Natural History of Ashkenazi Intelligence” by [Cochran](https://en.wikipedia.org/wiki/Gregory_Cochran), Hardy, and [Harpending](https://en.wikipedia.org/wiki/Henry_Harpending), argued on the basis of inherited diseases and the peculiar economic situation of Ashkenazi Jews in [medieval Europe](https://en.wikipedia.org/wiki/Middle_Ages), that Ashkenazi Jews as a group now inherit a cognitive profile that includes higher [verbal](https://en.wikipedia.org/wiki/Verbal_intelligence) and [mathematical](https://en.wikipedia.org/wiki/Mathematical) intelligence than other ethnic groups, along with lower [spatial intelligence](https://en.wikipedia.org/wiki/Spatial_intelligence).
One observational basis for inferring that Ashkenazi Jews have high intelligence is their prevalance in intellectually demanding fields. From 1901–2010, 21.5% of Nobel prize winners were Jewish, while Jews make up a much smaller fraction of the population of the countries represented. For example, 36% of Nobel prize winners from the [United States](https://en.wikipedia.org/wiki/United_States) have been Jewish, while Jews make up 2.1% of the U.S. population.
G. Cochran, J. Hardy and H. Harpending additionally cite the disproportionately high percentage of [Ashkenazi Chess Grandmasters](https://en.wikipedia.org/wiki/List_of_Jewish_chess_players) and [Fields Medalists](https://en.wikipedia.org/wiki/Fields_Medal) in mathematics, as well as winners of the [Turing Award](https://en.wikipedia.org/wiki/Turing_Award) in computer science.
Their median IQ is calculated at 117 in [From Chance to Choice: Genetics and Justice](https://www.amazon.com/Chance-Choice-Genetics-Justice/dp/0521660017) (2000), published by Cambridge University Press. This is 10 points higher than the generally-accepted IQ of their closest rivals—Northeast Asians—and almost 20% higher than the global average.”**

By modifying synaptic strength. Synapses are the points of connection between neurons.

I'll go all technical first, then explain the process in more common terms.

There is a famous dictum in neuroscience: neurons that fire together, wire together. This means that the synaptic efficiency between cells is increased when they tend to fire at the same time. This means that there will be a change so that the ability of cell A to make cell B fire will enhance. What's the nature of this change?

Glutamate is the brain's most common excitatory neurotransmitter. "Excitatory" in this case means that it increases the likelihood of an action potential going off in the receiving cell. Glutamate is released across the synapse and binds to glutamate receptors on the neighbouring cell. Let's look at two of them: AMPA and NMDA.

AMPA receptors are simple. Glutamate binds to them, they open ion channels that change the internal chemistry so that the likelihood of an action potential increases. Action potentials are all-or-nothing events. Cells either fire (1) or don't (0). So it's binary and rather neat.

NMDA receptors are similar to AMPA receptors, but they are different in that they require AMPA receptors to have been activated first before they are themselves activated. The membrane needs to be depolarized (brought closer to action potential threshold). This is because the ion channels opened by NMDA receptor activation are blocked by magnesium ions when the membrane is not sufficiently depolarized.

When NMDA receptors are activated, their associated ion channels lets in Ca^(2+) (calcium ions). This influx of Ca^(2+) leads to the activation of kinases (CAMKII, PKA, PKC, MAPK) and phosphotases. In the short run, this leads to the addition or subtraction of the number of AMPA receptors on the postsynaptic membrane. More AMPA = greater synaptic strength. Less AMPA = weaker synaptic strength. In the long run, there's a growth of dendritic spines.

All of the above is covered in great detail in introductory neuroscience textbooks. I recommend Kandel (highly detailed) or Purves (simple).

An important element in the process of synaptic plasticity is the Arc protein. Remarkably, Arc works like a virus. It encases mRNA in capsids and allows for interneuronal communication. Recently, it was found that one of its major roles is to strike a balance. When one synapse is strengthening, others are weakened. So there's a Darwinistic struggle involved even at this level.

So information is stored in synaptic connections. How is it used?

The information comes in the pattern of action potentials over time. This is called the spike train. Remember how I said action potentials are binary events? This means a spike train can look something like this: 00010111100100. This is clearly a neural code. It's entirely possible to decode it. For instance, you can listen in to a population of head-direction cells in the anterior thalamus of a rat while also recording its actual head movement. When you find neurons that respond to head direction (they spike more frequently when the head is oriented in a certain direction), you can later use the activity of these cells to know the rat's head direction at any time. If you also record the activity of speed cells, you can also trace the exact trajectory of the rat. This means that you can actually download neural data and accurately interpret it.

This is covered in Principles of Neural Coding.

It's usually difficult to understand something when technical terms are used; they often get in the way. So let's try to understand this using everyday terms.

Information is carried in the flow of energy through the brain. Information is stored by making it a little more difficult or a little easier for energy to flow down a certain path. Take associations, for instance. By repeatedly associating two different things, you are strengthening neural pathways between the two. If you don't use them, they will grow weaker with time.

Hope you're having a great day, Grey's Assistant! I've got three book recommendations!

The First is A Walk in the Woods, or any Bill Bryson Book (At Home and One Summer are great as well). Bill Bryson hikes the Appalachian Trail, discussing in humorous detail the process as well as delving into history on America's parks and trails.

https://www.amazon.com/Walk-Woods-Rediscovering-Appalachian-Official-ebook/dp/B000S1LSAM

Next is "The Grasshopper Trap" by Patrick McManus. Another columnist, this time appearing in a lot of fishing and game magazines. I doubt Grey has read these. They're fairly short stories and light reading. McManus tells (or invents) stories from his childhood living in a rural setting, and has a lot of funny stories from hunting and fishing trips from his adulthood. It's a little "blue collar comedy tour", and a little "guy humor" but pretty wholesome and really entertaining. I seriously doubt Grey would have read these, which is why I am suggesting it in the first place.

https://www.amazon.com/Grasshopper-Trap-Patrick-F-McManus-ebook/dp/B00723IO7Y/ref=sr_1_1?keywords=the+grasshopper+trap&qid=1565735667&s=digital-text&sr=1-1

Finally, and this one is the most niche of all, is Nature's Flyers: Birds Insects, and the Biomechanics of Flight by David E. Alexander. This book straddles the line between a textbook and non-fiction informative reading. It goes into different types of flight, the physics of natural flight, which animals do what kinds, why their bodies allow them to fly the ways they do, migration, how animals may have evolved flight, the impacts on the world... it's just a fascinating book, but it can require focus to read. This appeals to me since I studied Mechanical Engineering and love birds, but there's a chance it may tickle Grey's fancy as well. If he's looking something to test his enhanced focus after Project Cyclops, this is a good one.

Unfortunately this book is not on kindle. Used versions can be acquired from Amazon for around 20 dollars.

https://www.amazon.com/Natures-Flyers-Biomechanics-Alexander-2002-01-31/dp/B01FGNI53E/ref=sr_1_fkmr0_1?keywords=nature%27s+flyers%3A+birds+insects+and+the+biomechanics+of+flight&qid=1565735964&s=digital-text&sr=8-1-fkmr0

I'm in first year doing DI in Scotland, we've been on placement since November. Don't be nervous, speak up and ask questions. You'll quickly learn which members of staff will let you do as much as you're comfortable with, while others will pretty much just carry on with their job until you ask/offer to do something. If you get to choose which room you're working in, try and get in a room with someone who's been helpful before, you'll learn more.

Every radiographer does things slightly differently, and different departments will have different 'standard views' from the ones you learned in uni. Learn what they want and do it their way, not the way you were taught in uni. DON'T argue that 'well this is the way we were taught to do it'!

Be as helpful as possible. Clean up / wipe down surfaces, process cassettes (if you're using them), offer to go get patients changed, etc. Don't stand around looking bored, if you don't know something, ask about it, genuine curiosity will be rewarded.

Remember your TLD and anatomical markers - I found this book really useful for carrying around (fits perfectly in NHS tunic pockets). Sometimes the radiographers will even ask to borrow it, so brownie points for you.

Good luck on your placement!

For some basic info, check out the getting started guide in the sidebar.

What style of bow you get will be mostly guided by what kind of bow you are drawn to (and also what you plan on doing with it). There are some decent bows in the 100-150 price range (at least in a recurve or longbow). You should probably plan on 6-12 arrows to start off with (along with a few other necessary items). Arrows can be anywhere from $5 US each on up (arrows can be found cheaper, but quality might suffer).

As for learning on your own, /u/nusensei has a good youtube channel, not sure how many videos he has on technique, but good info. Archery Great Britain had some coaching videos online, you could search youtube for those as well, I think they go at least a little into technique but might be more tuned to coaches and not the archer.

KSLInternationals website has some good info on shooting.

You can also find some good books on archery, the only one I have read is Archery Anatomy, maybe other folks here could recommend other useful books.

Bottom line is, as with any other skill, teaching yourself will likely be more difficult than if you have a teacher, but you you don't have access to one than lots of reading and watching.

>Companies will compete to offer the best facilities to house your developing child.

Oh, great, let's bring capitalism into yet another aspect of our lives. You should read Crepuscular Dawn. The procedures you speak of will only be available to people who can afford it. Then what happens? You start creating a superior race. Super intelligent, super humans, if you could call them humans at all. Humans like you and I, born out of a vagina, without genetic engineering will become subhumans, likely 22nd century slaves to the super humans. Eventually the subhumans will die off, basically a man-induced evolution. By doing this, you would in effect be killing off your own kind.

I like the egg idea much better.

To your first question and based on your interests, the short answer is that there are many opportunities for ChemE for prostheses/materials and even artificial tissues. In fact, ChemE may place your ahead of bio or bme majors in some cases. For example, take a look at the book by Robert Langer, Tissue Engineering. It was one of my favorite book, as almost the go-to book for the area. Langer himself is an amazing leader in the area too. One particular case is that in many tissue engineering and prostheses/impacts, it is critical to design materials that have the right surface compound to stimulate or suppress particular cell responses, and that is where chemical engineering come in handy, and better if you have biochemistry background as well.

For your second question, an MS in biomedical engineering (BME) or engineering areas is a reasonable choice, while for biology a PhD is preferred. The reason is that for BME MS training is about more advanced engineering aspects and knowledge, which aims to help solve interdisciplinary problems and that is what industry job opening will expect you to do. The con is obvious, many research job still require PhD as qualification, exception is rare, but not impossible. For biology, it is less the case for post-graduate training but really about being able to conduct research, as the "problem-solving" in biology by its natural is mostly multi-year. MS in biology gives you small edge over BS. That say, PhD in biology takes a long time, and the first landing job may not always be that great in terms of salary. If you want to be in academia, Post-doc is usually the norm, which will add another 2 to 3 years.

Just my 2c based on what I heard from friends in the school where I got my PhD in engineering and a certification in biomedical imaging. It is one of the top 10 biomedical institutions, so there may be bias toward research/PhD.

I haven't read any of those authors' books but I only read books that describes processes or books that have actions items to apply to your life. I used to read books that only made me feel good and I wouldn't learn or improve on anything.

For example, I have a book that details a process to innovate the healthcare field. This process has been developed by Stanford for 13+ years through research and consultation of high-level executives, physicians, other healthcare professionals, large companies, small companies across the world. Stanford has been teaching this process for almost 13 years as well. This book is my bible. I'm going to use this process for developing my own startup.

My point is, this kind of book is much more valuable to me than the ones that make you feel good or just motivate you.

Are you interested in becoming a massage therapist, is that what you mean? What sort of self care are you talking about?

I don't know of any books or packages of information describing specific self care techniques for therapists, but maybe there is one out there. I just use the knowledge I have attained over the years and apply it to what I do, and what I need to fix with myself - and what I help my clients with.

Having knowledge and having awareness in nutrition, physiology, anatomy, remedial exercises/kinesiology ect. is all very important.. I could list text books which pertain to these areas, but I highly doubt you'd want to spend the money or time haha D:

There are some good stretching books out there here is one for example - I was told to buy one similar to it when I was in school, but I never did :s

If you know all the muscle oia's of the body, you shouldn't need a stretch book. This is a good book for a muscle visualization

if you are wanting to become a massage therapist though, I recommend you go to a reputable college and take the course, even if your area isn't regulated or not. It's totally worth it.

Disclaimer: I haven't read the following recommendations, but I was convinced to read them when I finish my current stash of books.

I don't work in the medical field, but my biggest hobby is powerlifting and I've spend many years doing tons of reading in scientific litterature about training and such. And when I was recommended the followings books by another powerlifter it seemed like a great opportunity to learn more. Biomechanics For Dummies and Anatomy and Physiology For Dummies

Hey H0RSED1K it's good to hear that I'm not the only one who feels this way.

I just want to graduate as soon as possible - I'd rather spend 40 hours a week working and getting paid, then 80 hours a week studying and paying for it.

One text we used in one of my classes was great, it is Molecular Biology of the Cell
I would love to read this entire text over an 8 month period or so, and complete the problems book

I feel that this would solidify my basic knowledge in biology.
Following this I would be able to target specific areas of interest.

I'm having errors accessing my Amazon wish list, but some of the books I can remember are as follows:

• Introduction to Biological Physics for the Health and Life Sciences
  
  
• Lab Ref, Volume 1: A Handbook of Recipes, Reagents, and Other Reference Tools for Use at the Bench
  
  
• Power, Sex, Suicide
  
  
• Short Protocols in Molecular Biology
  
  Also, you can consult some of the free courses online (MIT's OCW, Coursera.org, iTunes U, Open.edu) and once you obtain the syllabus you can review the material at your leisure. There are also sites like BenchFly.com, Jove.com that have videos of lab techniques and experiments. I presently don't have the time to review these in detail, so they are on my post-graduation queue.
  
  If you want to do this right, you'll probably have to hire a tutor to answer questions you might have.

I've personally referenced Human Biomaterials Applications numerous times. There are lots of biomaterial reference books. I haven't read many, but I know this one has been handy.


The biomedical engineering handbook is a great resource, as is the 2nd part-Medical devices and systems. These two of the 3 part volume would be the core. The 3rd part (electrical) may be less than essential for someone more biomechanically focused.


Another good reference is the Clinical Engineering Handbook. Not sure if your sister is going to go the direction of Clinical Engineering, but there's tons of relevant information that any engineer would be well served to know, since their products will (hopefully) end up in the clinic.

Thanks for your input!

Yeah I totally understand about medical moving slowly, the regulatory process surrounding it seems like a science in and of itself.

Apparently engineering in the medical industry also pays the best on average than most conventional engineering industries? It could be because they tend to work in capital cities, or maybe because medical professions are generally pretty highly paid, and some of that recognition rubs off onto the engineers (I’d take advantage of that gravy train for as much as I could!)

Thats interesting regarding low disruption, but understandable when looking at barriers to entry. I just started reading this book Biodesign , a massive book but lays out literally everything about the medical device industry and how to innovate within it. Thoroughly recommended.

The classic text is J.D. Murray's Mathematical Biology, but the last time I looked at it, it was a little long in the tooth. Maybe the second volume picks up a bit. No matter, look at it if you want to get a clear understanding of the background and classic problems.

There is a great deal of focus on computational molecular biology lately (networks, DNA computation, molecular programming, etc). Some of the people on the forefront of these fields include Niles Pierce, Erik Winfree and Drew Endy. Check out their papers and you'll get answers to many of your questions. On Winfree's page there is a whole list of collaborators which will keep you busy for a while.

The applied math degree will help, but if you really want to do well you'll need to learn a ton of biology. And I mean really learn it, there is nothing worse than a mathematician coming in and doing some cheap models of a biological system and claim that he has found a novel result when in fact it has no bearing on the underlying biology.

A guide like this would be priceless. Is any of it written yet? I think that your biggest challenge will be packaging that knowledge into a package that is approachable and easy to follow.

Stanford put together a reference like you're proposing for medical device development that helped me a lot in my first medical device project (http://www.amazon.com/Biodesign-Process-Innovating-Medical-Technologies/dp/0521517427/ref=sr_1_1?ie=UTF8&qid=1394453046&sr=8-1&keywords=biodesign). Unfortunately no one outside of academia has ever heard of it.

In terms of what I'd pay for something like this, I'll answer your question in the same way that I ask from your side of the table. Less than $10 would feel cheap. Greater than $40 would be too much. Probably a good value between $20 and $30. Given that people would need these various pieces of advice over many months, have you thought of a monthly access fee?

Is there a book you'd recommend that can give an overview of various techniques, but without lab protocol lists: i.e. "1.) Add 10mL of X", or a ton of equations. I'm not afraid of technical stuff as long as it's not too crazy. I've read 'The Cell' for instance - so I have general information on microbiology.

Something with chapter headings like: "Gene Insertion Techniques" or "Protein Sequencing Techniques" where the chapter would give you a broad overview of many techniques, why they matter and when to use these them.

These were some I was thinking of:

• Synthetic Biology: A Primer
  
• Biotechnology for Beginners
  
  Would love to get your take!

How are you with Anatomy? If not so great, first get this and learn as much in there as you can. Especially the neuro-musculo-skeletal stuff.

Now that you kind of know a little about anatomy, you'll need to learn how all those parts work. I recommend this kinesiology textbook.

Now that you know all the pieces and how they're supposed to work together, you'll need a text that talks about musculoskeletal dysfunctions and how to go about managing some of those conditions with exercise and other forms of treatment. I recommend this text for that.

Good luck!

I have James D Murray's Mathematical Biology which is quite good (although I must confess I haven't read all of it) but perhaps out of the scope of what you'd be looking for.

I've looked up the recommended reading in a mathematics module for a biology degree at my university and they recommend Paul Monk's Maths for Chemistry: A chemist's toolkit of calculations so perhaps that might be useful for you (although it seems from the title it would be more geared towards chemists, yet that's what they reccomend).

If you can't get OP's for free, but want to learn MSK exams here's another option (PDF is available free online):

https://www.amazon.com/Physical-Examination-Extremities-Stanley-Hoppenfeld/dp/0838578535

It's what people recommend ortho interns read.

For very fundamental information, I recommend Principles of Animal Locomotion. This isn't a book about algorithms, though; it's more of a book about the underlying dynamics of locomotion (bipedal and otherwise).


There are a lot of different approches to gait, both dynamically and statically stable. You'll find many in academic literature (proceedings of CLAWAR, IROS, and AAAI are good places to start). Papers related to the recent DARPA Robotics Challenge, and old but seminal work like Spring Flamingo and the DARPA Adaptive Suspension Vehicle are also good starting points.



Unfortunately the people on the forefront of this field don't publish their results.

I would get in touch with your program and see what the book list is like, but we use this book for two classes and it's FANTASTIC.

Merrill and Bontrager tend to be recommended by Americans, most of us Brits go for Clark's Positioning in Radiography.

Not read the 13th edition of the big boy book myself (basically everywhere has 12th edition, and I am not paying for a new one lol), but the only thing I disagree with in the first edition (since updated to 2nd edition) of the [little baby handbook for students and such] (https://www.amazon.co.uk/d/Books/Clarks-Handbook-Radiographers-Companion-Essential/1498726992/ref=pd_sim_14_5?_encoding=UTF8&psc=1&refRID=R5H91P80E0SZ5ZKVP0QH) was the ankle section, they describe a correct mortice view, but then the demonstrated image has their centring... somewhat high... :v

The main other book I consider a "must have" is Accident and Emergency Radiology, but as an ortho resident, you are likely past that (it is basic image interpretation, suitable for a junior doc or the average band 5/6 radiographer), though you might consider giving it a flick through anyway, it's not a long read, and is a very good quality book.

-

Edit: Interesting thing about Clark's - go back a few versions from the 12th edition and they were inexplicably using nude patients in a solid half of the demonstration images, flicking between covered and uncovered for seemingly no reason. God knows why. In any of the modern ones, they are all wearing swimsuits, at least!

I would recommend checking out later sections of this book http://www.amazon.com/Mathematical-Biology-Introduction-Interdisciplinary-Mathematics/dp/0387952233 (I can PM you a pdf if you want it). It goes into protein-protein bonding and protein-small molecule reactions in glorious mathematical sparseness, succinctly covers molecular biology/bioinformatic screens, and of course covers everyone's favorite intro PDE- the predator prey model; even after taking upper level undergraduate biochem/molecular biology courses seeing it all put so succinctly was a real treasure. Some of the math is relatively advanced for a developmental math course, but given that all of your biology/chemistry majors should have covered this material before (sans math in most cases) it shouldn't be too hard for them to jump into.

Yea sure. It’s a multidisciplinary field at the moment so we have almost as many computer scientists, Physicists and engineers as we do molecular biologists/ geneticists.

I’d recommend ‘synthetic biology - a primer’ as a first book:

https://www.amazon.co.uk/Synthetic-Biology-Paul-S-Freemont/dp/1848168632/ref=mp_s_a_1_2?ie=UTF8&qid=1550177278&sr=8-2&pi=AC_SX236_SY340_QL65&keywords=synthetic+biology+a+primer&dpPl=1&dpID=41xiiA-mjkL&ref=plSrch

Syn bio uses waterfall and agile approaches which are basically development life cycles. The waterfall approach for example proceeds as (1) system requirements, (2) design, (3) modelling, (4) synthesis, (5) assembly, (6) Transformation/implementation and (7) validation.

(2) and (3) use a lot of computer based skills such as computer assisted design (CAD) with standards such as SBOL (for 2), and computer assisted modelling (CAM) which includes the use of computer languages such as python and R (for 3). CAM also includes using markup languages such as SBML which is a good place to start with programmatic modelling.

(4), (5) and (6) are more molecular biology and genetic engineering based in terms of the practical sense. (4) Synthesis is very chemistry and physics based and there are separate companies that do this - we usually order our DNA from a synthesis company and then clone it to make loads for testing as it’s expensive . (5) is about assembling the DNA parts into modules and devices using methods such as Gibson assembly, golden gate assembly or BioBrick standards (which is an OG method developed by Tom Knight at MIT http://parts.igem.org/Assembly:Standard_assembly). (6) is about ‘installing’ the assembled DNA into the chosen cell chassis (cell fee systems are also up and coming) to install said function as a means of fulfilling the system requirements. (7) is about characterising your system to check it works and look for improvements.

There are loads of ways to apply yourself be it in the lab, on a computer or both. The book does a really good job in introducing you to the above so that you’re aware of how to do 1 through to 7 (except maybe 4). Ofc applying the skills is a whole other story (lab protocols and actually coding skills) but that comes with practise.

For a good explanation of the underlying physiology for why this is as described, see the book Archery Anatomy: An Introduction to Techniques for Improved Performance by Ray Axford

Rockwood and Green's is the bible IMHO. My first job was in ortho trauma and I slept with these volumes while I was rotating with the practice while still in school.

Wheeless is also a great website but sometimes info is incomplete

Physical Exam is another great resource. Really helped with those shoulder exam techniques, which always confused me for some reason

Physical Examination of the Spine and extremities by Stanley Hoppenfeld was helpful not only during my ortho rotation but in my ER and family med rotations.

Edit: link

Anatomy, Anatomy, Anatomy and this.

as /u/picklesandmustard said try to get in some PT aide hours and please empty your mind of what you think PT is before getting to PT school.

Principles of animal locomotion by R. McNeill Alexander. I haven't read all of it, but my professor swears by it.

http://www.amazon.com/Principles-Animal-Locomotion-McNeill-Alexander/dp/0691126348/ref=sr_1_5?ie=UTF8&qid=1334073029&sr=8-5