SENSORY NEURON INSULIN SIGNALING AND ITS ROLE IN DIABETIC NEUROPATHY

Diabetes is a global concern; approximately 366 million people are currently diagnosed worldwide. Complications of diabetes are numerous and can cause damage to almost every organ system in the body. Neuropathy is the most common complication associated with diabetes and severely impacts patients' quality of life. Diabetic neuropathy (DN) most commonly present as a distal symmetric polyneuropathy with a dichotomous presentation of either peripheral insensitivity or chronic pain. Eventually, patients can develop injury unawareness and foot ulcers, often resulting in amputation. Clearly establishing the mechanisms of diabetes-induced nerve damage will drive the development of more targeted and appropriate treatments. The pathogenesis of DN is multifactorial and the majority of research currently focuses on the toxic pathways induced by hyperglycemia. Interestingly though, insulin has been recently characterized to have direct effects on sensory neurons and is now believed to be a neurotrophic factor that is required for proper development, growth, and maintenance of the nervous system. Here, we tested the hypothesis that reduced sensory neuron insulin signaling contributes to DN pathogenesis via disrupted neurotrophic support. Results demonstrate that PI3K-Akt pathway activation in sensory neurons is insulin dose dependent and that insulin supplementation increases neurite outgrowth, establishing that sensory neurons are insulin responsive. These responses are blunted in type 2 diabetic mice, indicating that sensory neurons demonstrate signs of insulin resistance similar to muscle, liver, and adipose. However, sensory neuron insulin receptor knockout (SNIRKO) mice that maintain euglycemia do not display signs of DN. Suggesting that a disruptions solely in sensory neuron insulin signaling does not cause DN. Surprisingly though, SNIRKO mice are hyperinsulinemic and pancreatic islets from SNIRKO mice display increased insulin content, suggesting a possible feedback mechanism between sensory neuron insulin signaling and insulin production. These results are consistent with a recently described novel pathway of pancreatic beta cell regulation via sensory neuron neuropeptides. In conclusion, while sensory neurons are insulin responsive, reductions in sensory neuron insulin signaling without hyperglycemia does not cause signs of DN and it is most likely the combination of reduced insulin support and glucose neurotoxicity. Furthermore, the generation of SNIRKO mice has outlined a possible feedback mechanism through which sensory neurons modulate insulin production that could possible aid in establishing new therapeutic avenues for the treatment of diabetes

Speeding up simulations of relativistic systems using an optimal boosted frame

It can be computationally advantageous to perform computer simulations in a Lorentz boosted frame for a certain class of systems. However, even if the computer model relies on a covariant set of equations, it has been pointed out that algorithmic difficulties related to discretization errors may have to be overcome in order to take full advantage of the potential speedup. We summarize the findings, the difficulties and their solutions, and show that the technique enables simulations important to several areas of accelerator physics that are otherwise problematic, including self-consistent modeling in three-dimensions of laser wakefield accelerator stages at energies of 10 GeV and above.Comment: To be published in the proceedings of DPF-2009, Detroit, MI, July 2009, eConf C09072

Quantum Collective QCD String Dynamics

The string breaking model of particle production is extended in order to help explain the transverse momentum distribution in elementary collisions. Inspired by an idea of Bialas', we treat the string using a collective coordinate approach. This leads to a chromo-electric field strength which fluctuates, and in turn implies that quarks are produced according to a thermal distribution.Comment: 6 pages. Presented at SQM 2006. Submitted to J. Phys. G for publication in proceedings. Vers. 2: Minor revisions; final hadron spectrum calculation include

Dynamic Problems of Evolution

Evolution and growth of natural and man-made processes have impressed human beings from the very beginning. What is evolution? Is it the passage from an initial to a higher stage? What does "higher" mean in a world of many objectives? Is "higher" bound to the existence of monotonous indicators like entropy, or is it "gambling" within a predetermined combinatoric multifold of possibilities? Questions of this kind arise from the phenomena in our environment, from the spring-off of new species, but also from processes in our man-made technological world. How is the transition of basic innovation to technology and use of the corresponding products by society, what forecast can be made from increasing CO2, in the atmosphere on the impact on climate, from features of seismologic waves on future events etc. That means there is a strong connection between evolution processes and the emphasis of systems analysis as a help for strategic actions. This paper deals with general considerations about possible growth mechanisms as a base for creating valid growth models. But the main goal is to show how the parameters in growth models can be estimated using on one hand a fuzzy approach together with vector optimization and on the other hand a Bayesian approach. It can be seen that both approaches are useful and applicable and we get informations from one approach which the other one cannot give us. We studied already the growth of cracks in materials, processes well described in [10]. Preliminary results are contained in [13]. Research will be continued to identify the superposition of driving forces and of coupled systems in which oscillations can arise because of time delays between their driving-force pulses

Renormalization approach to many-particle systems

This paper presents a renormalization approach to many-particle systems. By starting from a bare Hamiltonian ${\cal H}= {\cal H}_0 +{\cal H}_1$ with an unperturbed part ${\cal H}_0$ and a perturbation ${\cal H}_1$,we define an effective Hamiltonian which has a band-diagonal shape with respect to the eigenbasis of ${\cal H}_0$. This means that all transition matrix elements are suppressed which have energy differences larger than a given cutoff $\lambda$ that is smaller than the cutoff $\Lambda$ of the original Hamiltonian. This property resembles a recent flow equation approach on the basis of continuous unitary transformations. For demonstration of the method we discuss an exact solvable model, as well as the Anderson-lattice model where the well-known quasiparticle behavior of heavy fermions is derived.Comment: 11 pages, final version, to be published in Phys. Rev.

Characteristics of survivors: growth and nutritional condition of early stages of the hake species <i>Merluccius paradoxus</i> and <i>M. capensis</i> in the southern Benguela ecosystem

Larval mortality in marine fish is strongly linked to characteristic traits such as growth and condition, but the variability in these traits is poorly understood. We tried to identify the variability in growth in relation to conditions leading to greater survival chances for early stages of Cape hake, Merluccius paradoxus and M. capensis, in the Benguela upwelling ecosystem. During two cruises in 2007 and one cruise in 2008, hake larvae and juveniles were caught. Otolith microstructures revealed a larval age ranging from 2 to 29 days post-hatching (dph), whereas juvenile age was 67–152 dph. RNA:DNA ratios, used to evaluate nutritional condition, were above the relevant threshold level for growth. No strong coupling between growth and condition was detected, indicating a complex relationship between these factors in the southern Benguela ecosystem. Merluccius paradoxus juveniles caught in 2007 (the surviving larvae of 2006) had significantly higher larval growth rates than larvae hatched in 2007 and 2008, possibly indicating selection for fast growth in 2006. High selection pressure on growth could be linked to predation avoidance, including cannibalism

MORPHOMETRIC STUDY FOR IDENTIFICATION OF THE BACTROCERA DORSALIS COMPLEX (DIPTERA : TEPHRITIDAE) USING WING IMAGE ANALYSIS

The Bactrocera dorsalis complex (Diptera: Tephritidae) used in this study included B. dorsalis, B. arecae, B. propinqua, B. pyrifoliae, B. verbascifoliae, and three new species complexes are species E, species K and species P. Bactrocera tau was used as an out-group. A total of 424 adults, which emerged from pupae collected from natural populations in Thailand, were prepared for wing measurements. Morphometric analysis was performed on measurements of wing vein characters. Wing images were captured in digital format and taken through digital  image processing to calculate the Euclidean distance between wing vein junctions. Discriminant and cluster analyses were used for dichotomy of classification processes. All 424 wing specimens were classified to species in terms of the percentage of "grouped" cases which yielded about 89.6% accurate identification compared with the formal description of these species. After clustering, the percentage of "grouped"cases yielded 100.0%, 98.9%, 98.1%, 95.2% and 84.6% accurate identification between the B. dorsalis complex and B. tau; B. arecae and Species E; B. dorsalis and B. verbascifoliae; B. propinqua and B. pyrifoliae; and species K and species P, respectively. This method of numerical taxonomy may be useful for practical identification of other groups of agricultural pests. Key words: Bactrocera dorsalis complex/wing image processing/morphometric/discriminant and cluster analyses

Morphometric Study for Identification of the Bactrocera Dorsalis Complex (Diptera : Tephritidae) Using Wing Image Analysis

The Bactrocera dorsalis complex (Diptera: Tephritidae) used in this study included B. dorsalis, B. arecae, B. propinqua, B. pyrifoliae, B. verbascifoliae, and three new species complexes are species E, species K and species P. Bactrocera tau was used as an out-group. A total of 424 adults, which emerged from pupae collected from natural populations in Thailand, were prepared for wing measurements. Morphometric analysis was performed on measurements of wing vein characters. Wing images were captured in digital format and taken through digital image processing to calculate the Euclidean distance between wing vein junctions. Discriminant and cluster analyses were used for dichotomy of classification processes. All 424 wing specimens were classified to species in terms of the percentage of "grouped" cases which yielded about 89.6% accurate identification compared with the formal description of these species. After clustering, the percentage of "grouped"cases yielded 100.0%, 98.9%, 98.1%, 95.2% and 84.6% accurate identification between the B. dorsalis complex and B. tau; B. arecae and Species E; B. dorsalis and B. verbascifoliae; B. propinqua and B. pyrifoliae; and species K and species P, respectively. This method of numerical taxonomy may be useful for practical identification of other groups of agricultural pests

Characteristics of survivors: growth and nutritional condition of early stages of the hake species Merluccius paradoxus and M. capensis in the southern Benguela ecosystem

Larval mortality in marine fish is strongly linked to characteristic traits such as growth and condition, but the variability in these traits is poorly understood. We tried to identify the variability in growth in relation to conditions leading to greater survival chances for early stages of Cape hake, Merluccius paradoxus and M. capensis, in the Benguela upwelling ecosystem. During two cruises in 2007 and one cruise in 2008, hake larvae and juveniles were caught. Otolith microstructures revealed a larval age ranging from 2 to 29 days post-hatching (dph), whereas juvenile age was 67–152 dph. RNA:DNA ratios, used to evaluate nutritional condition, were above the relevant threshold level for growth. No strong coupling between growth and condition was detected, indicating a complex relationship between these factors in the southern Benguela ecosystem. Merluccius paradoxus juveniles caught in 2007 (the surviving larvae of 2006) had significantly higher larval growth rates than larvae hatched in 2007 and 2008, possibly indicating selection for fast growth in 2006. High selection pressure on growth could be linked to predation avoidance, including cannibalism

Primary Arthrodesis for Diabetic Ankle Fractures

A grant from the One-University Open Access Fund at the University of Kansas was used to defray the author's publication fees in this Open Access journal. The Open Access Fund, administered by librarians from the KU, KU Law, and KUMC libraries, is made possible by contributions from the offices of KU Provost, KU Vice Chancellor for Research & Graduate Studies, and KUMC Vice Chancellor for Research. For more information about the Open Access Fund, please see http://library.kumc.edu/authors-fund.xml.Background: Treatment of ankle fractures in patients with diabetes is associated with increased complication rates. Ankle arthrodesis is considered a salvage procedure after failed ankle fracture fixation, yet primary ankle arthrodesis has been proposed as a treatment option for patients with significant diabetes-related complications. To date, the characteristics of patients who undergo primary ankle arthrodesis and the associated outcomes have not been described. Methods: A retrospective review was performed of 13 patients with diabetes who underwent primary arthrodesis for traumatic ankle fracture. Patient demographics were characterized in addition to their diabetes complications, Adelaide Fracture in the Diabetic Ankle (AFDA) score, and fracture type. Outcomes assessed included reoperation rates, infection rates, wound complications, nonunion/malunion, amputation, and development of Charcot arthropathy postoperatively. Results: Patients who underwent primary arthrodesis had high rates of diabetes complications, average AFDA scores of 6.4, and high rates of severe injuries, including 38.5% open fractures and 69.2% fracture dislocations. The overall complication rate for primary arthrodesis of ankle fractures in diabetes patients was more than 75% in this cohort. Complications included a 38.5% reoperation rate, 38.5% infection rate, 53.8% wound complication rate, and 23.1% amputation rate. Despite a high nonunion rate at the attempted fusion sites, 89.9% of fractures healed and patients had a stable extremity. Conclusion: This review is the first to characterize the epidemiology and complications of diabetes patients undergoing primary ankle arthrodesis for ankle fractures. In this cohort, patients with multiple diabetic complications and severe injuries underwent primary arthrodesis, which led to an overall high complication rate. Further research is needed to determine the appropriate treatment option for these high-risk patients, and tibiotalocalcaneal stabilization without arthrodesis may be beneficial