What's the deal with frame rates?

Whenever I watched my parents' television when younger I was often struck by the differences in appearance among films, sitcoms and adverts. I've never really been able to put into words what it is about the difference that I've noticed though, other than that films seem somehow more distant than sitcoms.

I just assumed it was to do with the quality of the type of film used to record in the first place, and nothing to do with our standard CRT television.

When the magnet went on the TV (and we didn't know about the YouTube videos showing you how to fix it) my dad got a new one - it's a flat screen digital affair.

Personally I'm not a fan (I still use a CRT myself) and find that there are artefacts on these modern new-fangled televisions that distract me. Worse, old episodes of Midsomer Murders look... a bit modern, I don't quite understand why they look so different.

I'm not sure if the more modern television is able to show the programmes as they were originally intended, and the earlier television wasn't, whereas more expensive (presumably) motion picture film already overcame the weaknesses of the television... does that sound plausible?

Very much looking forward to seeing the new Hobbit film but the thing I'm really intrigued about is to see how the two frame rates compare, I will probably go and see it in all the formats that I can find, just to check ;)

Don't assume that your private Twitter account is all that private

by @JoBrodie

You can protect your tweets (lock your account) by visiting the settings page, which can be found here: https://twitter.com/settings/account and put a tick next to 'Tweet privacy' which looks like this.

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Tweet privacy

Protect my Tweets If selected, only those you approve will receive your Tweets. Your future Tweets will not be available publicly. Tweets posted previously may still be publicly visible in some places. Learn more.

---

Note: ticking the box in the image above does NOT affect your Twitter privacy, you need to do this on your own Twitter account. Go to https://twitter.com/settings/account to do this (& log in)

Once you've done that then people who aren't following you cannot see your timeline without your permission. You'll have a little lock symbol next to your name and people have to send a request to follow you.

However I don't think any system is perfect and from looking at the comments on a similar post (about blocking people) I wondered if this might be giving people a false sense of security (or privacy).

There are several ways in which people can read directly, or at least work out, what's in your tweets.

1. Although Twitter makes it harder for someone to retweet a locked account (the 'Retweet' button doesn't work) this can't stop someone from copying the text manually and reposting it. If you think someone reading your timeline might do this (without your permission) then your tweets aren't perfectly private.

2. Anything that is visible on the screen of a device can be captured by my making a screenshot* - this can then be posted as an image accompanying a tweet. This also includes anything written on a private Facebook page or ANY system. If you can see it on your screen you can show it to someone else.

3. If you've ever heard someone talking on a phone you're hearing just one side of the conversation but you can usually work out what the person they're talking to might be saying, from how they respond. It's possible to search for someone's name on Twitter, or their @mentions, and see what people say to them even if you can't see what they say.

Even without a conversation I might give away what you're planning to do tonight if I talk about meeting in Ye Olde Pubbe at 7.30 and mention you and a couple of other people we're meeting. Someone else watching might reasonably assume that you might be at the pub too.

* How to make a screenshot / take a 'photo' of your screen
iPhone
Simultaneously press the on/off button at the top and the home button at the bottom, the screen is then saved as an image to your cameraroll.

PC/Windows
Press the PrtScr button which is usually somewhere to the top right of your keyboard, you may need to use the Function (Fn) key to activate it. The image is stored temporarily in your clipboard which is generally hidden, but you can view and edit the image by pasting it (Ctrl+V) into Paint / Paintbrush.

If you just want to copy the currently active window use Alt+PrtScrn (thanks to @zeno001 for pointing that one out!)

Mac/OSx
To take a copy of the entire screen use Ctrl+Command+Shift+3 (you can then paste it somewhere using Command+V) but if you want to save it as a picture file on the desktop remove the Ctrl bit, ie Command+Shift+3.

To select just a bit of the page to copy use either Ctrl+Command+Shift+4, or to save to desktop use Command+Shift+4.


Related reads

• What happens if you block someone on Twitter? What happens if they block you? (by me)
• Advice to celebrities about Twitter - for anyone in the public eye really (by me)

Trying to familiarise myself with the 'Computer Science teaching in schools' literature

As I'm helping out a bit more on another project at Queen Mary (on my boss Paul Curzon's cs4fn project) I'm trying to find out a bit more about 'the literature' relating to various outreach programmes that aim to engage school pupils in the world of computer science.

As I'm not familiar with either the literature, or the search strategies I should be employing to winkle it out (very familiar with life sciences / medical database searching, less so with computer science other than the ACM Digital Library and generic Web of Knowledge) I feel I'm fiddling about more than necessary.

Here are some papers I've found (some are written by my colleagues) on the topic, but what I'm particularly after is information about surveys of CS teachers - what do they want / need? There are already some looking at awareness of CS among high school children and first year students (who studied maths and were required to take a CS module, which they seemed to rather like) but I've not found many that have asked teachers.

I've also just discovered the CSTA (Computer Science Teachers' Association) which does have one or two surveys up its sleeves, so will be hunting there too.
http://www.csta.acm.org/Research/sub/CSTAResearch.html
and http://www.csta.acm.org/Research/sub/ExternalResearch.html

But my question so far (and it may not even be the right question of course!) is - what do computer science teachers want or need to help them teach computer science and encourage pupils to think computationally?

Bibliography - not systematic I'm afraid, mostly foraged and follow-on from citations. Many will prove to be not that relevant but the process of finding that out for myself has been useful! The order below is the order in which I downloaded PDFs or noted the citation. I've added links which should help anyone to track the papers down although I can't guarantee that you'll be able to access them (they open on my computer because I'm within an academic institution that is subscribed to most of them).

1. Published papers
2. Parliamentary discussions / reports to Government


1. Published papers
01 Myketiak (2012)
cs4fn: a flexible model for computer science outreach
http://dl.acm.org/citation.cfm?id=2325366

02 Curzon (2009)
Computational thinking (CT): on weaving it in
http://dl.acm.org/citation.cfm?id=1562941

03 Curzon (2008)
Engaging with computer science through magic shows
http://dl.acm.org/citation.cfm?id=1384320

04 Bell (2011)
Introducing students to computer science with programmes that don't emphasise programming
http://dl.acm.org/citation.cfm?id=1999904

05 Curzon (2007)
Serious fun in computer science
http://dl.acm.org/citation.cfm?id=1268785

06 [Multiple authors - conference proceedings]
Proceedings of the 12th annual SIGCSE conference on Innovation and technology in computer science education

07 Thies (2012)
Reflections on outreach programs in CS classes: learning objectives for "unplugged" activities
http://dl.acm.org/citation.cfm?id=2157136.2157281

08 Taub (2012)
CS Unplugged and Middle-School Students’ Views, Attitudes, and Intentions Regarding CS
http://dl.acm.org/citation.cfm?id=2160551

09 Blum (2007)
CS4HS: an outreach program for high school CS teachers
http://dl.acm.org/citation.cfm?id=1227320

10 Carter (2006)
Why students with an apparent aptitude for computer science don't choose to major in computer science
http://dl.acm.org/citation.cfm?id=1121352

11 Liu (2011)
A Survey on Computer Science K-12 Outreach: Teacher Training Programs
http://dl.acm.org/citation.cfm?id=2192607.2193197

12 Ragonis (2010)
A Survey of Computer Science Teacher Preparation Programs in Israel Tells Us: Computer Science Deserves a Designated High School Teacher Preparation!
http://dl.acm.org/citation.cfm?id=1734402

13 Porta (2010)
Dec-CS: The Computer Science Declining Phenomenon
http://www.iaeng.org/publication/WCECS2010/WCECS2010_pp1173-1178.pdf

14 Guzdal (2011)
Learning How to Prepare Computer Science High School Teachers
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=6036102&tag=1

15 Moura (2011)
Teaching a CS introductory course: An active approach
http://dl.acm.org/citation.cfm?id=1879857

16 Donathan (2011)
Successful K-12 Outreach Strategies
http://dl.acm.org/citation.cfm?id=1953211

17 Ragonis (2011)
A Study on Attitudes and Emphases in Computer Science Teacher Preparation
http://dl.acm.org/citation.cfm?id=1953320

18 Tillman (year not given on preprint, est > 2010)
Pex4Fun: Teaching and Learning Computer Science via Social Gaming
http://research.microsoft.com/apps/pubs/default.aspx?id=164417

19 Altinkurt, Y., & Yilmaz, K. (2012). Prospective science and mathematics teachers’ computer anxiety and learning styles. Energy Education Science and Technology Part B: Social and Educational Studies, 4(2), 933–942.

20 Sherrell (2012)
Tri-P-LETS: Changing the Face of High School Computer Science. Journal of Computers in Mathematics and Science Teaching, 31(1), 61-85. Chesapeake, VA: AACE.
http://www.editlib.org/p/38493

21  Curzon (2008)
Securing the future of computer science: computer science for fun
In: 9th Annual Conference of the Subject Centre for Information and Computer Sciences

22 Curzon (2009, though year not given on preprint)
cs4fn.org: Enthusing students about computer science
http://www.dcs.qmul.ac.uk/~pc/publications/2009/PCJBLRMPWCIEEIV2009preprint.pdf

23 Lapidot (2007)
The Israeli Summer Seminars for CS Leading Teachers
http://dl.acm.org/citation.cfm?doid=1268784.1268885

24 Cutts (2007)
Enthusing and informing potential computer science students and their teachers
http://dl.acm.org/citation.cfm?id=1268842

25 Major (2011)
Experiences of prospective high school teachers using a programming teaching tool
http://www.academia.edu/1110423/Experiences_of_Prospective_High_School_Teachers_Using_a_Programming_Teaching_Tool

26 Lapidot (2007)
Supporting the Growth of CS Leading Teachers
http://dl.acm.org/ft_gateway.cfm?id=1268895&type=pdf

27 Denning (2005)
Recentering computer science
http://dl.acm.org/citation.cfm?id=1096018

28 Cutts (2011)
Computing as the 4th "R": a general education approach to computing education
http://dl.acm.org/citation.cfm?id=2016938

29 Roberts (2005)


30 Gal-Ezer (2010)


31 Arkansas Legislation (2007)


32 Pontier (1996)


2. Parliamentary discussions / reports to Government
13 January 2012
Royal Society report
Computing in schools: Shut down or restart?
http://royalsociety.org/education/policy/computing-in-schools/report/

"There is a need to improve understanding in schools of the nature and scope of Computing. In particular there needs to be recognition that Computer Science is a rigorous academic discipline of great importance to the future careers of many pupils. The status of Computing in schools needs to be recognised and raised by government and senior management in schools."

"Every child should have the opportunity to learn Computing at school, including exposure to Computer Science as a rigorous academic discipline."

 And from the Summary document (Paul Nurse, foreword):

"It is becoming increasingly clear that studying Computer Science provides a ‘way of thinking’ in the same way that mathematics does, and that there are therefore strong educational arguments for taking a careful look at how and when we introduce young people to the subject."

9 February 2012
Schools: ICT
Education
http://www.theyworkforyou.com/wrans/?id=2012-02-09a.94280.h

13 March 2012
Schools: Computer Science
Northern Ireland Assembly
2.30pm
http://www.theyworkforyou.com/ni/?id=2012-03-13.0.137

"Given that the school viability audits use the percentage of pupils attaining grades A to C at GCSE as an indicator of a quality educational experience, and that it is generally recognised that ICT would give a better chance of pupils achieving a higher grade than other subjects such as computer science, does the Minister agree that schools are unlikely to choose to offer the more challenging option, unless they are actively encouraged to do so?"

22 March 2012
Digital Economy
Oral Answers to Questions — Culture, Media and Sport
10:30 am
http://www.theyworkforyou.com/debates/?id=2012-03-22b.916.3

" I am concerned about getting more young people involved in the industry, given that the number of people studying computer science is lower now than it was a decade ago and the proportion of women doing computer science has gone down to only 14%."

9 November 2012
ICT
Education
http://www.theyworkforyou.com/wrans/?id=2012-11-09a.126601.h

"...we are now consulting on withdrawing the existing ICT Programmes of Study and Attainment Targets from September 2012. This will free schools to develop more innovative ICT curricula with a greater focus on computer science, drawing on support from industry and other expert groups.

ICT will however remain a compulsory subject at all key stages, pending the outcome of the current review of the national curriculum in England." 

How to pipette properly

This is for the benefit of anyone making TV series or films that feature the transfer of small amounts of liquid from one place to another via pipette, in a laboratory setting - let's get it right. Or at least a bit right-er.

OK it's probably a bit rich of me to tell anyone how to pipette properly as it's been almost ten years since I stepped foot inside a lab, and to be fair most of the stuff I was handling wasn't amenable to plasticware (I was doing lipid science which requires some chemicals that tend to destroy plastic. The destruction of the plastic is less of a problem than the fact that contact between the chemical and the plastic can cause stuff that's in the plastic to 'leach out', wrecking the sample. Glass all the way.)

1. Gloves are there to protect you from the chemicals and whatnot, but importantly they're also there to protect whatever you're handling from you (from your sweat, dust and other stuff on your skin) so when wearing gloves don't fiddle with your hair or face. In some cases you might want to avoid picking up the phone or opening the door with a gloved hand, it does depend though. Ten years on and I still open doors with my foot in preference, where possible.

2. No 'skooshing' of the liquid from the pipette into the test-tube or wherever it's being placed. While this will certainly encourage mixing, which you often want, if you whoosh it in too fast you can lose some of it. If you skoosh it into a test-tube that already contains some liquid then you can end up jettisoning some of that liquid too - so you end up with the wrong amounts of everything. Or, you might form aerosols (tiny breathable liquid particles which you probably don't want). Not crucial if you're making orange squash but not so good in science.

Generally, you should angle the test-tube and touch the end of the disposable pipette tip against the lower side and depress the plunger gently. The liquid will then trickle down gracefully. If you want to mix it with another liquid (or dissolve something in the tube) you can suck up a bit of the slightly mixed liquid and repeat a few times (squidge it up and down a bit), or hold firmly (in your hand) but lightly against one of those vortex mixers).

I was once asked, by a new student in the lab, what the vortex mixer was for and I helpfully explained that you could put an Eppendorf (microcentrifuge) tube on it and it would mix it nicely for you. How we laughed when he took it a bit literally and he placed it on the mixer - without holding onto it - and it pinged off across the lab.

Next week: How to make fatty acid methyl esters. Kidding :)

In support of Lewisham A&E

• SaveLewishamHospital.com
• Petition in support of Lewisham A&E and Maternity Services
• Consultation on South London Healthcare NHS Trust (closes 13 December 2012, at midnight)
• Public meeting (tonight, 3 Dec 2012, 7pm) at Calabash Day Centre, off Lewisham High St - nearest railway station appears to be Ladywell.

I fell through a stepladder a few years ago and lacerated (their word) my leg. My flatmate called for an ambulance and off I went to Lewisham A&E for stitches and a tetanus shot.

Despite excellent care the wound didn't quite heal properly and I ended up having to have 'surgical debridement' where they cut back the bits that don't heal¹ to a 'bleeding wound bed' after which 'regranulation' can occur. Thanks to the surgeon, Mr Sweeney (not a name you forget), anaesthetists², nurses, cleaners and people who made me some toast... I and my leg made a full recovery over a couple of months (it was quite a big wound). I now look like I've had a rather triangular chunk taken out of my leg by a very neat shark.

It was a ridiculously hot summer (2003) and while it was all healing I managed to scratch the area just next to the large square plaster. The spreading red marks concerned me as I'd been warned to watch out for cellulitis and I took myself back to Lewisham A&E wondering if I was going to sound like a hypochondriac for saying at reception "I think I might have cellulitis". They didn't mess about and I got some antibiotics (amoxicillin and flucloxacillin³ and the suspected death mites cleared up in a few days.

So I'd be pretty sad if Lewisham A&E wasn't there, and from what I can gather, so would an awful lot of other local people. There are some things that people can read, sign or comment on in the links above.

It's not just Lewisham A&E, their maternity services are under threat too. More at Londonist.

Mind you, if they do have to close Lewisham A&E they might also want to do something about that massive gap between the platform and the trains at Lewisham railway station - I can't help thinking that probably results in the creation of a fair few patients.

Little superscripty footnotes
1. looking back, kinda gangrenous
2. who answered every question I asked about anaesthesia. I had that propofol in the back of my hand
3. I've never been able to pronounce that, although I can manage Eyjafjallajökull no bother thanks to the BBC's pronunciation guide.