Feeding effect of selenium enriched rotifers on larval growth and development in red sea bream Pagrus major

Feeding trials were conducted to investigate the effect of selenium (Se)-enriched rotifers on growth and development of red sea bream Pagrus major larvae. Fish were reared from fertilized eggs (98% hatch rate) to 20. days post hatch (dph) at 19. °C with two different food sources; non-enriched S-type rotifers (0.0. μg. Se/g D.W., control diet) or Se-enriched rotifers (2.2. μg. Se/g D.W., Se-enriched diet) at 10. rotifers/mL, respectively. On the last day of larviculture, the Se-enriched diet accelerated growth and developmental stage of fish larvae. The larvae fed Se-enriched rotifers were advanced in the following parameters compared to those fed control diet: total length (6.06 vs 5.53. mm), standard length (5.74 vs 5.26. mm), head length (1.46 vs 1.28. mm), eye diameter (0.57 vs 0.50. mm), the number of caudal fin rays (5.8 vs 1.9), and the proportion of individuals undergoing notochord flexion (55 vs 3%). Fish larvae of 20. dph showed higher Se concentration (9.5 ± 0.2. μg/g DW) with the Se-enriched diet than with the control diet (1.3 ± 0.3. μg/g DW), but there were no significant differences in the composition of polyunsaturated fatty acids which significantly affect larval growth and development. Therefore, the feeding of Se enriched rotifers enhanced growth and development of the red sea bream P. major larvae

中華人民共和国におけるウイルス性神経壊死症の発生

中華人民共和国の種苗生産施設で生産された孵化7-45日齢のチャイロマルハタとキジハタに異常遊泳を特徴とする大量死が発生した。病魚の脳および網膜組織には空胞形成が認められ, 神経細胞などに直径25-28nmのエンベロープを持たない球形ウイルス粒子が観察された。また, 病魚から魚類ノダウイルスの外被タンパク質抗原および遺伝子が検出されたことから, 本病はウイルス性神経壊死症(VNN)と診断された。本報告は中華人民共和国における VNN の初記載である。The viral etiology of mass mortalities of groupers, Epinephelus coioides and E. akaara, cultured in the People's Republic of China was examined. Disease outbreaks occurred in 7 to 45 day-old fish with erratic swimming motion and marked vacuolation was observed in the brain and retina of the affected fish. The piscine nodavirus (the Betanodavirus), the causative agent of viral nervous necrosis (VNN), was detected in the affected tissues by electron microscopy, indirect fluorescent antibody test and reverse transcription-polymerase chain reaction. This paper is the first record of the agent in the People's Republic of China

Encoding of sequence boundaries in the subthalamic nucleus of patients with Parkinson's disease

Sequential behaviour is widespread not only in humans but also in animals, ranging in different degrees of complexity from locomotion to birdsong or music performance. The capacity to learn new motor sequences relies on the integrity of basal ganglia-cortical loops. In Parkinson's disease the execution of habitual action sequences as well as the acquisition of novel sequences is impaired partly due to a deficiency in being able to generate internal cues to trigger movement sequences. In addition, patients suffering from Parkinson's disease have difficulty initiating or terminating a self-paced sequence of actions. Direct recordings from the basal ganglia in these patients show an increased level of beta (14-30 Hz) band oscillatory activity associated with impairment in movement initiation. In this framework, the current study aims to evaluate in patients with Parkinson's disease the neuronal activity in the subthalamic nucleus related to the encoding of sequence boundaries during the explicit learning of sensorimotor sequences. We recorded local field potential activity from the subthalamic nucleus of 12 patients who underwent deep brain stimulation for the treatment of advanced Parkinson's disease, while the patients in their usual medicated state practiced sequences of finger movements on a digital piano with corresponding auditory feedback. Our results demonstrate that variability in performance during an early phase of sequence acquisition correlates across patients with changes in the pattern of subthalamic beta-band oscillations; specifically, an anticipatory suppression of beta-band activity at sequence boundaries is linked to better performance. By contrast, a more compromised performance is related to attenuation of beta-band activity before within-sequence elements. Moreover, multivariate pattern classification analysis reveals that differential information about boundaries and within-sequence elements can be decoded at least 100 ms before the keystroke from the amplitude of oscillations of subthalamic nucleus activity across different frequency bands, not just from the beta-band. Additional analysis was performed to assess the strength of how much the putative signal encoding class of ordinal position (boundaries, within-sequence elements) is reflected in each frequency band. This analysis demonstrates that suppression of power in the beta-band contains the most class-related information, whereas enhancement of gamma band (31-100 Hz) activity is the second main contributor to the encoding. Our findings support the hypothesis that subthalamic nucleus-mediated gating of salient boundary elements during sequence encoding may be a prerequisite for the adequate acquisition of action sequences and the transition to habitual behaviour