Pigeons (Columba livia) have excellent flying and orienting abilities and are ideal study subjects for biologists who research the underlying neurological mechanisms that modulate flying and allow birds to find their way home. These mechanisms also attract the engineers who want to apply pigeon locomotion to the design of flying robots. Here, we identified the motor-related brain nuclei and revealed their relationship in spatial distribution in pigeons under light anesthesia and freely moving conditions respectively. Flapping and lateral body movements were successfully elicited when electrical microstimulation was applied to the diencephalon, medial part of the midbrain, and medulla oblongata of lightly anesthetized pigeons (N = 28) whose heads were fixed. The current thresholds for stimulating different nuclei and behavior ranged from 10 μA to 20 μA. During freely moving tests (N = 24), taking off and turning were induced by a wireless stimulator through microelectrodes implanted in specific nuclei or brain regions. The results showed that electrical stimulation of these nuclei elicited the desired motor behavior. In addition, regulatory mechanisms were identified in the motor-related regions and nuclei of pigeons. Overlapping in the behavior elicited by stimulation of different regions indicates that complicated neural networks regulate motor behavior. Therefore, more studies need to be conducted involving simultaneous stimulation at multiple points within the nuclei involved in the networks.

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Background There is a dearth of published literature that demonstrates the impact of a Guide to Reading Biomedical English Literature course on new Chinese medical postgraduates. Keeping this gap in mind, the objectives of this study were to assess the factors associated with course effectiveness using the teacher, postgraduate and organizational factors. Methods This study was conducted at Nanjing Medical University from December 2014 to December 2015. The participants were 440 new graduate students from different medical specialties. At baseline, each student was assessed for teacher factors, individual factors and organizational factors using a self-administered structured scored anonymous questionnaire. After that, Pearson chi-square analysis was conducted to evaluate the factors that impact teacher factors (knowledge level, teaching style, individualized teaching, logical teaching, heuristic teaching, literature difficulty, bilingual teaching), individual factors (gender, attitude toward studying, previewing literature, English literacy level) and course management (such as teaching objectives and assessment system) on this course. Furthermore, multiple logistic regression analyses were performed to determine the impact of the above factors on our outcome variables (knowledge level, teaching style, individualized teaching, heuristic teaching, study attitude, previewing literature, management). Results Nearly all of the participants (420 of 440, 95.5%) thought this course was helpful for learning to read scientific literature and understanding scientific research design. Multivariate logistic regression analyses showed that the participants perception of the course as effective was associated with teachers’ high knowledge level (Adjusted Odds Ratio, AOR = 49.673; 95% confidence interval, 95% CI = 4.28, 575.90). In addition, heuristic teaching was found to be significantly associated with a positive teaching effect of teaching (AOR = 12.76; 95% CI = 1.78, 91.64). Furthermore, the participants perception of the course as effective was associated with positive attitude toward studying (AOR = 25.004; 95% CI = 2.51, 249.09). Previewing literature was also associated with course effectiveness (AOR = 0.02; 95% CI = 0.04, 0.11). Conclusions This study indicated that the course effectiveness of the Guide for Reading Biomedical English Literature was associated with i) teachers’ knowledge, ii) heuristic teaching, iii) students’ positive attitude, and iv) students’ previewing literature. Electronic supplementary material The online version of this article (10.1186/s12909-019-1731-7) contains supplementary material, which is available to authorized users.

AimTo explore the chronic effects of metformin on testosterone levels in men with type 2 diabetes mellitus (T2DM).MethodsThis is a secondary analysis of a real-world study evaluating the efficacy and safety of premixed insulin treatment in patients with T2DM via 3-month intermittent flash glucose monitoring. Male patients aged 18-60 who were using metformin during the 3-month study period were included as the metformin group. The control group included males without metformin therapy by propensity score matching analysis with age as a covariate. Testosterone levels were measured at baseline and after 3-month treatment.ResultsAfter 3-month treatment, the control group had higher levels of total testosterone, free and bioavailable testosterone than those at baseline (P<0.05). Compared with the control group, the change of total (-0.82 ± 0.59 vs. 0.99 ± 0.59 nmol/L) and bioavailable (-0.13 ± 0.16 vs. 0.36 ± 0.16 nmol/L) testosterone levels in the metformin group significantly decreased (P=0.036 and 0.029, respectively). In Glycated Albumin (GA) improved subgroup, the TT, FT, and Bio-T levels in the control subgroup were higher than their baseline levels (P < 0.05). Compared with the metformin subgroup, TT level in the control subgroup also increased significantly (P=0.044). In GA unimproved subgroup, the change of TT level in the metformin subgroup was significantly lower than that in the control subgroup (P=0.040).ConclusionIn men with T2DM, 3-month metformin therapy can reduce testosterone levels, and counteract the testosterone elevation that accompanied with the improvement of blood glucose.Clinical Trial Registrationhttps://www.clinicaltrials.gov/ct2/show/NCT04847219?term=04847219&draw=2&rank=1.

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The recent history of activity input onto granule cells (GCs) in the main olfactory bulb can affect the strength of lateral inhibition, which functions to generate contrast enhancement. However, at the plasticity level, it is unknown whether and how the prior modification of lateral inhibition modulates the subsequent induction of long-lasting changes of the excitatory olfactory nerve (ON) inputs to mitral cells (MCs). Here we found that the repetitive stimulation of two distinct excitatory inputs to the GCs induced a persistent modification of lateral inhibition in MCs in opposing directions. This bidirectional modification of inhibitory inputs differentially regulated the subsequent synaptic plasticity of the excitatory ON inputs to the MCs, which was induced by the repetitive pairing of excitatory postsynaptic potentials (EPSPs) with postsynaptic bursts. The regulation of spike timing-dependent plasticity (STDP) was achieved by the regulation of the inter-spike-interval (ISI) of the postsynaptic bursts. This novel form of inhibition-dependent regulation of plasticity may contribute to the encoding or processing of olfactory information in the olfactory bulb.

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