Crystal structures of 2-amino-2-oxoethyl 4-bromobenzoate, 2-amino-2-oxoethyl 4-nitrobenzoate and 2-amino-2-oxoethyl 4-aminobenzoate monohydrate

The title molecules were synthesized by the reaction of 4-substituted sodium benzoates with chloroacetic acid amide in the presence of dimethylformamide. The yields of 2-amino-2-oxoethyl 4-bromobenzoate, C9H8BrNO3, I, 2-amino-2-oxoethyl 4-nitrobenzoate, C9H8N2O5, II, and 2-amino-2-oxoethyl 4-aminobenzoate monohydrate, C9H10N2O3·H2O, III, are 86, 78 and 88%, respectively. The low yield of II is explained by the reduced reactivity of the molecule in a nucleophilic exchange reaction because of the negative induction and negative mesomeric effects of the nitro group on the benzene ring. Single crystals were obtained from the products under the same (temperature and solvent) conditions. In the case of III, the crystals formed as a monohydrate. In all three crystal structures, the same type of intermolecular N—H...O hydrogen bonds are observed, but the molecules differ in some torsion angles as well as in the dihedral angles between the mean planes of the benzene rings and the amide groups.

Trait cheerfulness sensitivity to positive and negative affective states

Recent research suggests that trait cheerfulness triggers larger state cheerfulness variations after facing amusing and sad clips. The present study aimed at replicating and extending these effects. A sample of 80 psychology students (68 women) was selected depending on their scores in trait cheerfulness. Participants watched a set of positive and negative pictures, which was accompanied by statements, and were asked to report their affective states before and after watching them. The results showed that high versus low trait cheerfulness participants reported a larger increase in state cheerfulness, valence, and joy measures after the positive induction and a larger decrease in state cheerfulness after the negative induction. The results replicate and extend previous findings and support the idea that high trait cheerfulness people are more sensitive to the affective environment.

Negative induction effect of graphite N on graphene quantum dots: tunable band gap photoluminescence

We synthesized nitrogen-doped graphene quantum dots (N-GQDs) under a high temperature range of 800–1200 °C and high pressure of 4.0 GPa through a solid-to-solid process.

Differential Multiple-Schedule Interactions in Rats

Three experiments examined multiple-schedule interactions in a free-operant paradigm for rats. In Exps. 1 and 2 three rats each and in Exp. 3 five rats were given extended multiple variable-interval baseline training before being shifted to multiple variable-interval extinction. Visual discriminative stimuli and regular extinction, which allowed nonreinforced responding, were used in Exps. 1 and 2, but auditory discriminative stimuli and retraction of the lever to prevent responding during extinction were used in Exp. 3. Positive behavioral contrast was observed in only one out of six rats in Exps. 1 and 2, while negative induction was observed in the other five subjects. However, contrast was observed at some point in training for all five subjects in Exp. 3. The differential multiple-schedule interactions were attributed to the introduction of an additional stimulus-reinforcer dependency with regard to the presence vs absence of the lever in Exp. 3. Results support an autoshaping or additivity account of behavioral contrast.

Respiration in the Desert Locust

1. During normal flight of the desert locust, auxiliary ventilating mechanisms do not appear, and dorso-ventral abdominal pumping continues at increased frequency and amplitude. When flight stops hyperventilation together with auxiliary forms appear briefly. Removal of the abdomen has shown that pterothoracic and neck ventilation are adequate for sustained flight. 2. Spiracles 2 and 3 open wide during flight: when flight is weaker they make incipient closing movements. A central inhibitory reflex controls their activity, in addition to the peripheral action of carbon dioxide on spiracle 2. The incipient closing movements are shown not to have a functional significance; they are probably the expression of two competing mechanisms, and may arise by negative induction. 3. Spiracles 1 and 4-10 remain synchronized with ventilation, and thereby permit adequate ventilation of the central nervous system. 4. The isolation of the pterothoracic tracheal system is enhanced by the occlusion of two pairs of cross-links. The occlusion of a further three pairs in the prothorax and head ensures that the head has priority on the inspired air. 5. The occlusion of all the cross-links takes place after the first instar, at which time spiracle synchronization first regularly appears and a directed airstream becomes possible. 6. In flight there are two largely independent ventilating systems. The first, a two-way system, ventilates the flight muscles through the open spiracles 2 and 3 and is pumped by the flight movements. The second, a one-way system, ventilates primarily the central nervous system and is pumped by the abdomen, in through the dorsal orifice of spiracle 1, and out through spiracles 5-10.