TNS Exam 1 100- VERIFIED SOLUTIONS, SCORED A+.

TNS Exam 1 100% VERIFIED SOLUTIONS,
SCORED A+



What .is .the .primary .motivation .of .experimentation? .- .CORRECT .ANSWER-To
.disprove .or .fail .to .disprove .a .hypothesis


What .does .the .scientific .method .consist .of? .- .CORRECT .ANSWER-Formalized
.steps .where .by .a .theory .is .formed, .tested, .and .revised


What's .the .purpose .of .hypothesis .testing? .- .CORRECT .ANSWER-Used .to
.evaluate .the .strength .of .evidence .from .the .sample .and .provides .a .framework
.for .making .determinations


When .should .a .t-test .be .used? .- .CORRECT .ANSWER-When .comparing .the
.averages .of .two .groups, .with .relatively .small .samples


How .to .read .T .value? .- .CORRECT .ANSWER-- .larger .T-value .= .the .more .different
.the .groups .are
- .more .different .groups .are .= .better .chances .that .groups .are ."significant"

How .to .read .P .value? .- .CORRECT .ANSWER-- .smaller .P .value .= .more .different
.the .groups .are .
- .threshold: ..05 .or ..01 .usually .
- .the .probability .of .being .wrong .if .you .conclude .that .your .groups .are .different

When .to .use .an .ANOVA .test? .- .CORRECT .ANSWER-When .making .multiple
.comparisons .between .groups
- .because .if .we .were .to .do .a .t-test, .it .would .be .more .likely .to .make .an .incorrect
.conclusion .since .each .additional .comparison .with .a .t-test .multiplies .probability
.of .making .a .mistake


What .is .the .alpha .value? .- .CORRECT .ANSWER-the .probability .of .making .a .type
.1 .error .(false .positive) .that .a .researcher .is .willing .to .make .(usually .it .is .0.05)
- .threshold .value .used .to .determine .whether .a .test .statistic .is .statistically
.significant


What .is .a .sampling .distribution? .- .CORRECT .ANSWER-Mean, .Proportion, .and
.T-sampling .distribution
- .generally .uses .the .central .limit .theorem .for .construction

What .is .the .critical .value? .- .CORRECT .ANSWER-It .is .the .cutoff .between
.retaining .or .rejecting .null .hypothesis

, - .regions .where .test .statistic .is .unlikely .to .lie

What .is .the .obtained .value? .- .CORRECT .ANSWER-

What .is .Magnetic .Resonance .Imaging? .- .CORRECT .ANSWER-It .is .a .cylindrical
.magnet .with .an .open .bore, .and .has .an .electromagnet. .It .is .usually .super
.conducting. .It .various .transmit .and .receive .antennae .through .radiofrequency.


How .does .the .magnetic .field .of .MRI .work? .- .CORRECT .ANSWER-As .protons
.rotate, .it .creates .a .tiny .magnetic .field. .The .external .field .(B0) .aligns .the .protons
.parallel .and .antiparallel .to .B0. .There .are .more .protons .that .align .parallel
.compared .to .antiparallel.


What .is .precession? .- .CORRECT .ANSWER-Protons .precess .about .an .axis .and
.the .frequency .depends .on .external .field .strength .(B0) .and .the .type .of .atom


What .is .excitation? .- .CORRECT .ANSWER-sending .energy .into .spinning .nuclei
.which .puts .them .in .a .higher .energy .level


What .are .T1 .scans? .- .CORRECT .ANSWER-They .involve .single .90 .degree
.pulses. .As .the .signal .decays .contrast .is .enhanced, .the .overall .strength .signal
.weakens.
- .lightest: .white .matter
- .gray: .gray .matter

What .is .a .signal? .- .CORRECT .ANSWER-It .is .a .simple .echo .taken .at .time .T1 .of
.a .single .pulse.


What .is .T2 .scans? .- .CORRECT .ANSWER-It .involves .two .pulses: .one .pulse .is .to
.flip .the .protons .to .90 .degree .precession, .the .other .pulse .is .to .flip .dephasing
.protons .into .phase .and .at .180 .degrees. .
- .It .tales .advantage .of .tissues .whose .protons .take .longer .to .fall .out .of .phase
- .darkest: .white .matter
- .gray: .gray .matter

What .is .repetition .of .MRI? .- .CORRECT .ANSWER-It .is .the .balance .of .temporal
.resolution .& .signal .to .noise .ratio. .
- .How .long .the .tissue .can .relax .to .B0 .before .next .pulse

What .is .TE? .- .CORRECT .ANSWER-The .time .after .90 .degree .pulse .that .the .echo
.is .sampled .and .depends .on .magnet .strength .and .type .of .scan
- .T1: .14msec
-T2: .90msec

What .is .the .repetition .time .(TR) .of .T1 .and .T2 .MRI? .- .CORRECT .ANSWER-T1:
.500msec
T2: .4000msec