On simple Shamsuddin derivations in two variables.

We study the subgroup of k -automorphisms of k ⁢ [ x , y ] which commute with a simple derivation d of k ⁢ [ x , y ] . We prove, for instance, that this subgroup is trivial when d is a shamsuddin simple derivation. in the general case of simple derivations, we obtain properties for the elements of this subgroup.

Accuracy of in vivo palpation-guided acromioclavicular joint injection assessed with contrast material and fluoroscopic evaluations.

Objective: The purpose of this study was to evaluate the accuracy of in vivo acromioclavicular (AC) joint injections without fluoroscopic guidance and assess whether patient demographics affected the accuracy of injections.

Materials And Methods: A consecutive cohort of patients who presented with painful acromioclavicular joints was prospectively evaluated. All patients had clinical and radiographic evidence of AC arthritis, had failed conservative measures, and thus had received intraarticular corticosteroid injections.

Medial prefrontal cortex inactivation attenuates the diurnal rhythm in amphetamine reward.

Psychostimulant reward, as assessed via the conditioned place preference (CPP) paradigm, exhibits a daily rhythm with peaks in the late dark and early light periods, and a nadir near the light-to-dark transition. While this diurnal rhythm is correlated with neural activity in several corticolimbic structures, the brain regions mediating this behavioral rhythm remain unknown. Here, we examine the role of the ventral medial prefrontal cortex (mPFC).

Diurnal rhythms in neural activation in the mesolimbic reward system: critical role of the medial prefrontal cortex.

Previous evidence suggests a circadian modulation of drug-seeking behavior and responsiveness to drugs of abuse. To identify potential mechanisms for rhythmicity in reward, a marker of neural activation (cFos) was examined across the day in the mesolimbic reward system. Rats were perfused at six times during the day [zeitgeber times (ZTs): 2, 6, 10, 14, 18, and 22], and brains were analysed for cFos and tyrosine hydroxylase (TH)-immunoreactive (IR) cells.

The transcription factor Runx2 is under circadian control in the suprachiasmatic nucleus and functions in the control of rhythmic behavior.

Runx2, a member of the family of runt-related transcription factors, is rhythmically expressed in bone and may be involved in circadian rhythms in bone homeostasis and osteogenesis. Runx2 is also expressed in the brain, but its function is unknown. We tested the hypothesis that in the brain, Runx2 may interact with clock-controlled genes to regulate circadian rhythms in behavior.