Neuromuscular control of the point to point and oscillatory movements of a sagittal arm with the actor–critic reinforcement learning method

In this study, we have used a single link system with a pair of muscles that are excited with alpha and gamma signals to achieve both point to point and oscillatory movements with variable amplitude and frequency.

The system is highly nonlinear in all its physical and physiological attributes. The major physiological characteristics of this system are simultaneous activation of a pair of nonlinear muscle-like-actuators for control purposes, existence of nonlinear spindle-like sensors and Golgi tendon organ-like sensor, actions of gravity and external loading. Transmission delays are included in the afferent and efferent neural paths to account for a more accurate representation of the reflex loops.

A reinforcement learning method with an actor–critic (AC) architecture instead of middle and low level of central nervous system (CNS), is used to track a desired trajectory. The actor in this structure is a two layer feedforward neural network and the critic is a model of the cerebellum. The critic is trained by state-action-reward-state-action (SARSA) method. The critic will train the actor by supervisory learning based on the prior experiences. Simulation studies of oscillatory movements based on the proposed algorithm demonstrate excellent tracking capability and after 280 epochs the RMS error for position and velocity profiles were 0.02, 0.04?rad and rad/s, respectively.     

The Receptor-Like Protein ReMAX of Arabidopsis Detects the Microbe-Associated Molecular Pattern eMax from Xanthomonas

As part of their immune system, plants have pattern recognition receptors (PRRs) that can detect a broad range of microbe-associated molecular patterns (MAMPs). Here, we identified a PRR of Arabidopsis thaliana with specificity for the bacterial MAMP eMax from xanthomonads. Response to eMax seems to be restricted to the Brassicaceae family and also varied among different accessions of Arabidopsis. In crosses between sensitive accessions and the insensitive accession Shakhdara, eMax perception mapped to RECEPTOR-LIKE PROTEIN1 (RLP1). Functional complementation of rlp1 mutants required gene constructs that code for a longer version of RLP1 that we termed ReMAX (for receptor of eMax). ReMAX/RLP1 is a typical RLP with structural similarity to the tomato (Solanum lycopersicum) RLP Eix2, which detects fungal xylanase as a MAMP. Attempts to demonstrate receptor function by interfamily transfer of ReMAX to Nicotiana benthamiana were successful after using hybrid receptors with the C-terminal part of ReMAX replaced by that of Eix2. These results show that ReMAX determines specificity for eMax. They also demonstrate hybrid receptor technology as a promising tool to overcome problems that impede interfamily transfer of PRRs to enhance pathogen detection in crop plants.     

Age and parasitism status of Tuta absoluta eggs alter the foraging responses of the predator Nabis pseudoferus

We studied the effect of Trichogramma brassicae Bezdenko (Hymenoptera: Trichogrammatidae) parasitism of Tuta absoluta Meyrick (Lepidoptera: Gelechiidae) eggs on the foraging behavior of Nabis pseudoferus Remane (Hemiptera: Nabidae) feeding on T. absoluta eggs of different ages. Older parasitized eggs (48–72 h old) were rejected after probing with the probosis. A separate experiment showed that probing did not harm developing parasitoids. Bugs greatly reduced their feeding times on older parasitized eggs and spent more time grooming and probing eggs and leaves. Predators exhibited a type III functional response to 24 h-old eggs, but a type II response to older eggs, whether parasitized or not. 24 h-old eggs suffered higher attack rates, and required less handling time than older eggs. Although the predatory efficiency of N. pseudoferus was reduced in the presence of parasitized eggs, the partial refuge enjoyed by T. brassicae in older eggs may permit an additive impact on the pest, and should facilitate the joint augmentation of both species against T. absoluta.

     

Effects of Dietary Bovine Lactoferrin on Growth Performance and Immuno-physiological Responses of Asian Sea Bass (Lates calcarifer) Fingerlings

Probiotics and Antimicrobial Proteins - The aim of this study was to evaluate the effects of lactoferrin (Lf) on growth and feeding performance, biochemical and immune parameters in Asian sea bass...     

Biochemical characterization of digestive proteases and carbohydrases of the carob moth,Ectomyelois ceratoniae (Zeller) (Lepidoptera: Pyralidae)

Digestive proteinases and carbohydrases of Ectomyelois ceratoniae (Zeller) larvae were investigated using appropriate substrates and inhibitors. Midgut pH in larvae was determined to be slightly alkaline. Midgut extracts showed optimum activity for proteolysis of hemoglobin at pH 9–12. Midgut proteinases also hydrolyzed the synthetic substrates of trypsin, chymotrypsin, and elastase at pH 8–11. Maximum digestive α-amylase activity was also observed at pH 8–11. However, optimum activity for α- and β-glucosidase occurred at pH 5–8. Alpha- and β-galactosidases optimum activities occurred at pH 5 and pH 6, respectively. Inhibitors of serine proteases were effective on midgut serine proteases (trypsin and chymotrypsin proteases). Zymogram analyses revealed at least five bands of total proteolytic activity in the larval midgut. Protease-specific zymogram analyses revealed at least four, two, and one isozymes for trypsin-, chymotrypsin-, and elastase-like activities respectively. Two α-amylase isozymes were found in the midgut of fifth instar larvae and in the whole bodies of 1st through 5th instar larvae. Zymogram studies also revealed the presence of one and two bands of activity for β- and α-glucosidase, respectively. Recycling of α-amylase and proteases in the larval midgut was not complete. At least one isozyme of trypsin, chymotrypsin, elastase, and α-amylase were not recycled and were observed in the larval hindgut.