Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Ex Input:
Context: A scale for the Assessment and Rating of Ataxia (SARA) was developed for evaluation of autosomal dominant cerebellar ataxias (ADCA) and was also recommended for clinical trials of Friedreich's ataxia patients (FRDA). FRDA, unlike ADCA, is characterized as being a sensory type of ataxia for which the disease-specific Friedreich ataxia rating scale (FARS) was developed. The objective of this study was to determine whether SARA and FARS scores are associated with posturographic parameters in FRDA patients.", 'Adult patients with genetically confirmed FRDA (n=11) and ADCA (n=13) were evaluated by SARA, FARS and posturography.', "FRDA patients' postural stability parameters, in stance with visual control, correlated with balance impairment in FARS (r=0.622; p<0.05) and SARA (r=0.735; p<0.05). Without visual control, only FARS correlated with balance impairment (r=0.732; p<0.05).
Answer: The SARA, in FRDA patients, correlates with stance with visual control but not without visual control which emphasizes sensory ataxia. This suggests that application of the SARA in Friedreich's ataxia patients according to posturography is possible but presumably limited and FARS, although being a more time consuming scale, may have advantages over SARA in FRDA patients.

Ex Output:
Is application of a Scale for the Assessment and Rating of Ataxia ( SARA ) in Friedreich 's ataxia patients according to posturography limited?


Ex Input:
Context: Nonviral vectors based on polyethylenimine (PEI) usually contain an excess of PEI that is not complexed to DNA. Since unbound PEI contributes to cellular and systemic toxicity, purification of polyplexes from unbound PEI is desirable.', 'Size exclusion chromatography (SEC) was used to purify PEI polyplexes of free PEI. Transfection properties of purified polyplexes and the effect of free PEI on gene delivery were studied in vitro and in vivo after systemic application into mice.', 'SEC did not change the size and zeta-potential of polyplexes. Independent of the amount of PEI used for complex formation, purified PEI polyplexes had the same final PEI nitrogen/DNA phosphate ratio of 2.5. Notably, purified PEI polyplexes demonstrated low cellular and systemic toxicity. High transfection efficiency was achieved with purified polyplexes at high DNA concentrations (8-15 microg/ml). At low DNA concentrations (2-4 microg/ml) gene transfer with purified particles was less efficient than with polyplexes containing free PEI both in vitro and in vivo. Mechanistic studies showed that free PEI partly blocked cellular association of DNA complexes but was essential for the following intracellular gene delivery. Adding free PEI to cells treated with purified particles with a delay of up to 4 h resulted in significantly enhanced transfection efficiency compared with non-purified particles or purified particles without free PEI.
Answer: This study presents an efficient method to remove free PEI from PEI polyplexes by SEC. Our results from transfection experiments demonstrate that free PEI substantially contributes to efficient gene expression but also mediates toxic effects in a dose-dependent manner. Purified polyplexes without free PEI have to be applied at increased concentrations to achieve high transfection levels, but exhibit a greatly improved toxicity profile.

Ex Output:
Does purification of polyethylenimine polyplexes highlight the role of free polycations in gene transfer?


Ex Input:
Context: An event-related brain potential (ERP) study investigated how different processing stages involved in face identification are reflected by ERP modulations, and how stimulus repetitions and attentional set influence such effects.', 'ERPs were recorded in response to photographs of familiar faces, unfamiliar faces, and houses. In Part I, participants had to detect infrequently presented targets (hands), in Part II, attention was either directed towards or away from the pictorial stimuli.', "The face-specific N170 component elicited maximally at lateral temporal electrodes was not affected by face familiarity. When compared with unfamiliar faces, familiar faces elicited an enhanced negativity between 300 and 500 ms ('N400f') which was followed by an enhanced positivity beyond 500 ms post-stimulus ('P600f'). In contrast to the 'classical' N400, these effects were parietocentrally distributed. They were attenuated, but still reliable, for repeated presentations of familiar faces. When attention was directed to another demanding task, no 'N400f' was elicited, but the 'P600f' effect remained to be present.
Answer: While the N170 reflects the pre-categorical structural encoding of faces, the 'N400f' and 'P600f' are likely to indicate subsequent processes involved in face recognition. Impaired structural encoding can result in the disruption of face identification. This is illustrated by a neuropsychological case study, demonstrating the absence of the N170 and later ERP indicators of face recognition in a prosopagnosic patient.

Ex Output:

Do event-related brain potentials distinguish processing stages involved in face perception and recognition?