NodeJS Variable Scope

I'm very, very new to the whole NodeJS stack, and I'm trying to rough up a simple login system for practice.

Jumping to my question,

app.js

...
var mongoose = require( 'mongoose' );
var templates = require( './data/inc.js' ); // includes schema structures
...

---

user.js - included in inc.js

...
module.exports =
{
    "Schema" : new exports.mongoose.Schema({
      "uid": mongoose.Schema.Types.ObjectId,
      "username": { type:String, unique:true },
      "alias": String,
      "credentials":
      {
        "salt": String,
        "password": String,
        "key": String
      },
      "profile":
      {
        "age": { type: Number, min: 18 }
      },
      "last_login": Date,
      "updated": { type: Date, default: Date.now }
    })
}
...

The 'user.js' script above will not work because it doesn't have access to the mongoose object variable instantiated in the 'app.js' script. In PHP any included/required scripts would be able to access variables from the parent script, but in NodeJS as I know it for example I have to re-require/state the mongoose variable in order to create my schema tree.

user.js

...
* var mongoose = require( 'mongoose' ); // must include in script to use mongoose object

module.exports
{
   ...
}
...

Is there any work-around that will allow me the same scope access as PHP?