Compensating for Ensemble-Specificity Effects when BuildingFacial Models

Multidimensional Anxiety and Content-specificity Effects in Preferential Processing of Threat

European Psychologist ◽

10.1027//1016-9040.8.4.252 ◽

2003 ◽

Vol 8 (4) ◽

pp. 252-265 ◽

Cited By ~ 9

Author(s):

Manuel G. Calvo ◽

P. Avero ◽

M. Dolores Castillo ◽

Juan J. Miguel-Tobal

Keyword(s):

Selective Attention ◽

Cognitive Biases ◽

Naming Task ◽

Color Naming ◽

Memory Bias ◽

Ego Threat ◽

Phobic Anxiety ◽

Relative Contribution ◽

Content Specificity ◽

Specificity Effects

We examined the relative contribution of specific components of multidimensional anxiety to cognitive biases in the processing of threat-related information in three experiments. Attentional bias was assessed by the emotional Stroop word color-naming task, interpretative bias by an on-line inference processing task, and explicit memory bias by sensitivity (d') and response criterion (β) from word-recognition scores. Multiple regression analyses revealed, first, that phobic anxiety and evaluative anxiety predicted selective attention to physical- and ego-threat information, respectively; cognitive anxiety predicted selective attention to both types of threat. Second, phobic anxiety predicted inhibition of inferences related to physically threatening outcomes of ambiguous situations. And, third, evaluative anxiety predicted a response bias, rather than a genuine memory bias, in the reporting of presented and nonpresented ego-threat information. Other anxiety components, such as motor and physiological anxiety, or interpersonal and daily-routines anxiety made no specific contribution to any cognitive bias. Multidimensional anxiety measures are useful for detecting content-specificity effects in cognitive biases.

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Purification and biochemical characterization of polyphenol oxidase from seeds of melon (Citrullus colocynthis)

Nova Biotechnologica et Chimica ◽

10.36547/nbc.v19i2.777 ◽

2020 ◽

Vol 19 (2) ◽

pp. 223-231

Author(s):

David Morakinyo Sanni ◽

Catherine Joke Adeseko ◽

Samuel Olufemi Bamidele

Keyword(s):

Gallic Acid ◽

Polyphenol Oxidase ◽

Fruits And Vegetables ◽

Biochemical Characterization ◽

Apparent Molecular Weight ◽

Citrullus Colocynthis ◽

Effects Of Ph ◽

Melon Seeds ◽

Processing And Storage ◽

Specificity Effects

Polyphenol oxidase (PPO) is an enzyme that is responsible for the enzymatic browning of fruits and vegetables. This is generally undesired process and need to be prevented in food technology. PPO from seeds of Citrullus colocynthis was purified, the physicochemical properties such as effects of pH and temperature, substrate specificity, effects of inhibitors and cations on PPO activity and the kinetic parameters for four substrates namely, catechol, L-DOPA, gallic acid and tyrosine, were determined. The purification steps resulted in 41-fold with 10 % yield, and the optima pH and temperature values for PPO from C. colocynthis were found to be pH 7.0 and 60 °C, respectively using catechol as substrate. About 9 % enzyme initial activity was retained after 60 min of incubation at 80 °C, and the apparent molecular weight was determined as 42 kDa by partially denaturing SDS-PAGE. PPO activity was inhibited by ascorbic acid, SDS and certain divalent (Ca2+, Zn2+, Mg2+ and, Fe2+) and monovalent (Na+) metal. Moreover, purified enzyme solution showed diphenolase activity toward catechol, gallic acid, L-DOPA and monophenolase activity toward tyrosine, therefore, tyrosinase was identified as the only one PPO in C. colocynthis seeds. This study revealed the use of temperature above 80 °C to inhibit PPO activity during processing and storage of melon seeds.

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