Arc magazine is brought to you by the makers of New Scientist, and their first issue is out now (buy it in various physical/electronic formats from http://www.newscientist.com/arc). On the cover you’ll see ‘Featuring new fact and fiction from: Margaret Atwood, Stephen Baxter, M John Harrison, China Miéville, Hannu Rajaniemi, Alastair Reynolds, Adam Roberts and Bruce Sterling.’

That’s a polite way of saying, ‘Behold! You are in the presence of some seriously heavy hitters in the Science Fiction field.’ As for how to send them submissions:

The short answer is: by invitation. Arc runs off commissions, not submissions. We’re going to publish four issues this year, and we have a pretty clear idea about what we’re going to do in each of them. We’ve already been in touch with many of the authors we’d like to work with over the remainder of the year, and we’ll be in touch with the rest soon.

However, Arc magazine is open to submissions in the form of a competition closing April 8, with the theme, ‘The Future Always Wins’:

Arc, in collaboration with The Tomorrow Project, is looking for new, original stories – between 3000 and 5000 words – set in the near future. What do we mean by that? Near enough to be recognisable, but not so near as to be boring. Technology, in whatever guise – from robotics 
to synthetic biology to geoengineering – 
should feature prominently, but we’re looking for stories, not theses, and the human element will have to be compelling. The current theme for submissions 
is THE FUTURE ALWAYS WINS.

Read the full details and submit here (note: you will need a free SubMishMash account to submit): http://www.arcfinity.org/submit

Scape Zine specialises in Young Adult speculative fiction and poetry:

All Scape fiction and poetry must contain a speculative component. We’re into sword and sorcery, urban fantasy, magical realism, hard sci-fi, cyberpunk, alternate history, supernatural, myth and legend, post-apocalyptic, dark, light and all shades in between. If you can imagine it, we’ll consider it. That being said, to catch our attention you’re going to need to bring something fresh and edgy if your story features well-worn ideas such as vampires or time travel.

Young Adult fiction is an ever-growing field, and it’s great to see a dedicated magazine like Scape Zine:

Scape’s YA focus doesn’t mean we want ‘dumbed down’ or ‘censored’ stories. Quite the opposite. YA for us is broadly defined. It means fiction that is relevant, meaningful and of particular interest to young people. We’re not putting a specific age bracket on ‘young people’ and we aim for our publication to appeal to the ‘young’ and ‘young at heart’ alike.

They accept short fiction up to 8,000 words, and poetry up to 100 lines. Their pay rates are a generous 1 cent U.S. per word for original short stories, with a U.S. $10 minimum payment, and a flat $25 for poetry. Note that they pay via PayPal.

You can find all submission details here: http://scapezine.com/guidelines/