Internal state effects on behavioral shifts in freely behaving praying mantises (Tenodera sinensis).

How we interact with our environment largely depends on both the external cues presented by our surroundings and the internal state from within. Internal states are the ever-changing physiological conditions that communicate the immediate survival needs and motivate the animal to behaviorally fulfill them. Satiety level constitutes such a state, and therefore has a dynamic influence on the output behaviors of an animal. In predatory insects like the praying mantis, hunting tactics, grooming, and mating have been shown to change hierarchical organization of behaviors depending on satiety. Here, we analyze behavior sequences of freely hunting praying mantises (Tenodera sinensis) to explore potential differences in sequential patterning of behavior as a correlate of satiety. First, our data supports previous work that showed starved praying mantises were not just more often attentive to prey, but also more often attentive to further prey. This was indicated by the increased time fraction spent in attentive bouts such as prey monitoring, head turns (to track prey), translations (closing the distance to the prey), and more strike attempts. With increasing satiety, praying mantises showed reduced time in these behaviors and exhibited them primarily towards close-proximity prey. Furthermore, our data demonstrates that during states of starvation, the praying mantis exhibits a stereotyped pattern of behavior that is highly motivated by prey capture. As satiety increased, the sequenced behaviors became more variable, indicating a shift away from the necessity of prey capture to more fluid presentations of behavior assembly.

Predatory behavior changes with satiety or increased insulin levels in the praying mantis (Tenodera sinensis).

At any given moment, behavior is controlled by a combination of external stimuli and an animal's internal state. As physiological conditions change, vastly different behaviors might result from the same stimuli. For example, the motivation to hunt and hunting strategy are influenced by satiety. Here, we describe how sensory responsiveness and motor activity of a praying mantis (Tenodera sinensis) change as the insect feeds, leading to an altered hunting strategy. We further show that these changes can be induced by injection of insulin, which likely functions as a metabotropic indicator. Praying mantises directed their attention toward real and simulated prey less often as they fed and became sated. The range of distance and azimuth at which prey was detected decreased as did pursuit of prey, while opportunistic close-range attacks persisted. Together, these sensorimotor changes are indicative of a behavioral paradigm shift from 'pursuit' to 'ambush'. A similar effect was induced in starved praying mantises injected with 0.05 ml of 200 µg ml-1 bovine insulin. These experiments showed that insulin injection into the circulating hemolymph is sufficient to decrease prey orientation as well as in prey-directed locomotor behaviors (tracking and pursuit). The effects of prey consumption and insulin injection were similarly dose dependent. These results suggest that insulin is a signal of internal, physiological conditions that can modify responses to external stimuli. A change in hunting strategy thus results from coordinated effects of a neurohormone on a set of independent sensorimotor processes and the overall activity level of the animal.

Decline in infection-related morbidities following drug-mediated reductions in the intensity of Schistosoma infection: A systematic review and meta-analysis.

BACKGROUND: Since 1984, WHO has endorsed drug treatment to reduce Schistosoma infection and its consequent morbidity. Cross-sectional studies suggest pre-treatment correlation between infection intensity and risk for Schistosoma-related pathology. However, evidence also suggests that post-treatment reduction in intensity may not reverse morbidity because some morbidities occur at all levels of infection, and some reflect permanent tissue damage. The aim of this project was to systematically review evidence on drug-based control of schistosomiasis and to develop a quantitative estimate of the impact of post-treatment reductions in infection intensity on prevalence of infection-associated morbidity. METHODOLOGY/PRINCIPAL FINDINGS: This review was registered at inception with PROSPERO (CRD42015026080). Studies that evaluated morbidity before and after treatment were identified by online searches and searches of private archives. Post-treatment odds ratios or standardized mean differences were calculated for each outcome, and these were correlated to treatment-related egg count reduction ratios (ERRs) by meta-regression. A greater ERR correlated with greater reduction in odds of most morbidities. Random effects meta-analysis was used to derive summary estimates: after treatment of S. mansoni and S. japonicum, left-sided hepatomegaly was reduced by 54%, right-sided hepatomegaly by 47%, splenomegaly by 37%, periportal fibrosis by 52%, diarrhea by 53%, and blood in stools by 75%. For S. haematobium, hematuria was reduced by 92%, proteinuria by 90%, bladder lesions by 86%, and upper urinary tract lesions by 72%. There were no consistent changes in portal dilation or hemoglobin levels. In sub-group analysis, age, infection status, region, parasite species, and interval to follow-up were associated with meaningful differences in outcome. CONCLUSION/SIGNIFICANCE: While there are challenges to implementing therapy for schistosomiasis, and praziquantel therapy is not fully curative, reductions in egg output are significantly correlated with decreased morbidity and can be used to project diminution in disease burden when contemplating more aggressive strategies to minimize infection intensity.

Neuromechanical model of praying mantis explores the role of descending commands in pre-strike pivots.

Praying mantises hunt by standing on their meso- and metathoracic legs and using them to rotate and translate (together, 'pivot') their bodies toward prey. We have developed a neuromechanical software model of the praying mantis Tenodera sinensis to use as a platform for testing postural controllers that the animal may use while hunting. Previous results showed that a feedforward model was insufficient for capturing the diversity of posture observed in the animal (Szczecinski et al 2014 Biomimetic and Biohybrid Syst. 3 296-307). Therefore we have expanded upon this model to make a flexible controller with feedback that more closely mimics the animal. The controller actuates 24 joints in the legs of a dynamical model to orient the head and translate the thorax toward prey. It is controlled by a simulation of nonspiking neurons assembled as a highly simplified version of networks that may exist in the mantid central complex and thoracic ganglia. Because of the distributed nature of these networks, we hypothesize that descending commands that orient the mantis toward prey may be simple direction-of-intent signals, which are turned into motor commands by the structure of low-level networks in the thoracic ganglia. We verify this through a series of experiments with the model. It captures the speed and range of mantid pivots as reported in other work (Yamawaki et al 2011 J. Insect Physiol. 57 1010-6). It is capable of pivoting toward prey from a variety of initial postures, as seen in the animal. Finally, we compare the model's joint kinematics during pivots to preliminary 3D kinematics collected from Tenodera.

Gallbladder neurofibroma presenting as chronic epigastric pain - Case report and review of the literature.

CONTEXT: Benign nonepithelial neoplasms of the gallbladder are unusual. The majority of gallbladder neurofibromas are found incidentally in the gallbladder specimens following cholecystectomy. There have been only few reports in the literature describing this rare entity. In this study we report a case of gallbladder neurofibroma presenting as chronic epigastric pain in a young patient. CASE REPORT: A thirty two year old otherwise healthy man presented to our clinic with chronic epigastric pain symptom after eating. Physical examination, laboratory and radiologic workups were unremarkable for signs of biliary tract diseases. Past medical and surgical histories were significant only for neurofibromatosis type I. Due to persistent symptomatology, the patient was taken to the operating room for a diagnostic laparoscopy followed by laparoscopic cholecystectomy. Open conversion was necessitated because of the presence of a gallbladder mass preventing safe anatomic dissection. Surgical pathology revealed plexiform neurofibroma with noninflamed gallbladder. The postoperative course was unremarkable and the patient was pain free at 3 weeks postoperatively. CONCLUSIONS: Benign neoplasms such as gallbladder neurofibroma should be included in the differential diagnosis for chronic epigastric pain symptom in a young otherwise healthy patient with neurofibromatosis. Diagnostic laparoscopy should be considered in an individual presenting with this condition.

Surgical management of endoscopically unresectable duodenal gangliocytic paraganglioma in a patient with partial upper gastrointestinal obstruction.

CONTEXT: Gangliocytic paragangliomas are unusual and often misunderstood tumors that occur almost exclusively in the second portion of the duodenum, although they have been described in other sites such as the urinary bladder, spermatic cord, prostate, urethra, uterus and scalp. We describe our experience with the surgical management of an endoscopically unresectable gangliocytic paraganglioma located in the third part of the duodenum causing a partial upper gastrointestinal obstruction. CASE REPORT: A fifty-two-year-old male presented to the Geisinger clinic with a four-year history of postprandial projectile vomiting associated with epigastric discomfort. Computed tomography scan revealed an oval-shaped filling defect in the third part of the duodenum. Endoscopic ultrasonography showed a 22 × 16 × 35 mm submucosal mass that was not amenable to an endoscopic resection. Exploratory laparotomy revealed an absence of extraduodenal involvement. A long-stalked tumor was successfully excised and extruded through a longitudinal duodenotomy. The pathology report showed a gangliocytic paraganglioma with negative lymph nodes. CONCLUSIONS: In patients presenting with prolonged recurrent attacks of vomiting, diagnostic workup to exclude anatomic causes is mandatory. Gangliocytic paraganglioma must be considered in the differential diagnosis of an intraduodenal tumor.

Organ allocation: a case for not transplanting the violent criminal.

As organ transplantation outcomes become ever more successful, vigilance as to appropriate recipient selection must be ensured, for without careful monitoring the already great disparity between organ supply and demand will continue to grow. There is a public perception that justice requires equal access to treatment for all, but this is not always the case. We suggest that, while violent felons do not account for a large number of transplant recipients, transplanting even one such individual should be deemed inadvisable-and could well be fraught with irreparable public repercussions.