Recurrent Hypoglycemia Is Associated with Loss of Activation in Rat Brain Cingulate Cortex

A subset of people with diabetes fail to mount defensive counterregulatory responses (CRR) to hypoglycemia. Although the mechanisms by which this occurs remain unclear, recurrent exposure to hypoglycemia may be an important etiological factor. We hypothesized that loss of CRR to recurrent exposure to hypoglycemia represents a type of stress desensitization, in which limbic brain circuitry involved in modulating stress responses might be implicated. Here, we compared activation of limbic brain regions associated with stress desensitization during acute hypoglycemia (AH) and recurrent hypoglycemia (RH). Healthy Sprague Dawley rats were exposed to either acute or recurrent 3-d hypoglycemia. We also examined whether changes in neuronal activation were caused directly by the CRR itself by infusing epinephrine, glucagon, and corticosterone without hypoglycemia. AH increased neuronal activity as quantified by c-fos immunoreactivity (FOS-IR) in the cingulate cortex and associated ectorhinal and perirhinal cortices but not in an adjacent control area (primary somatosensory cortex). FOS-IR was not observed after hormone infusion, suggesting that AH-associated activation was caused by hypoglycemia rather than by CRR. Importantly, AH FOS-IR activation was significantly blunted in rats exposed to RH. In conclusion, analogous with other models of stress habituation, activation in the cingulate cortex and associated brain areas is lost with exposure to RH. Our data support the hypothesis that limbic brain areas may be associated with the loss of CRR to RH in diabetes

Genetically-Based Olfactory Signatures Persist Despite Dietary Variation

Individual mice have a unique odor, or odortype, that facilitates individual recognition. Odortypes, like other phenotypes, can be influenced by genetic and environmental variation. The genetic influence derives in part from genes of the major histocompatibility complex (MHC). A major environmental influence is diet, which could obscure the genetic contribution to odortype. Because odortype stability is a prerequisite for individual recognition under normal behavioral conditions, we investigated whether MHC-determined urinary odortypes of inbred mice can be identified in the face of large diet-induced variation. Mice trained to discriminate urines from panels of mice that differed both in diet and MHC type found the diet odor more salient in generalization trials. Nevertheless, when mice were trained to discriminate mice with only MHC differences (but on the same diet), they recognized the MHC difference when tested with urines from mice on a different diet. This indicates that MHC odor profiles remain despite large dietary variation. Chemical analyses of urinary volatile organic compounds (VOCs) extracted by solid phase microextraction (SPME) and analyzed by gas chromatography/mass spectrometry (GC/MS) are consistent with this inference. Although diet influenced VOC variation more than MHC, with algorithmic training (supervised classification) MHC types could be accurately discriminated across different diets. Thus, although there are clear diet effects on urinary volatile profiles, they do not obscure MHC effects

Carpal tunnel syndrome and the "double crush" hypothesis: a review and implications for chiropractic

Upton and McComas claimed that most patients with carpal tunnel syndrome not only have compressive lesions at the wrist, but also show evidence of damage to cervical nerve roots. This "double crush" hypothesis has gained some popularity among chiropractors because it seems to provide a rationale for adjusting the cervical spine in treating carpal tunnel syndrome. Here I examine use of the concept by chiropractors, summarize findings from the literature, and critique several studies aimed at supporting or refuting the hypothesis. Although the hypothesis also has been applied to nerve compressions other than those leading to carpal tunnel syndrome, this discussion mainly examines the original application – "double crush" involving both cervical spinal nerve roots and the carpal tunnel. I consider several categories: experiments to create double crush syndrome in animals, case reports, literature reviews, and alternatives to the original hypothesis. A significant percentage of patients with carpal tunnel syndrome also have neck pain or cervical nerve root compression, but the relationship has not been definitively explained. The original hypothesis remains controversial and is probably not valid, at least for sensory disturbances, in carpal tunnel syndrome. However, even if the original hypothesis is importantly flawed, evaluation of multiple sites still may be valuable. The chiropractic profession should develop theoretical models to relate cervical dysfunction to carpal tunnel syndrome, and might incorporate some alternatives to the original hypothesis. I intend this review as a starting point for practitioners, educators, and students wishing to advance chiropractic concepts in this area

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Where Should Governments Invest? The Impact of Economic, Political, Social and Technological Factors on the Formation of New Firms

The purpose of this paper is to identify the factors that affect the creation of new firms. We take into consideration economic, political, social and technological factors which should also help governments realize the areas that we found to have the greatest impact. The study relies on data from international organizations from which we construct an ordered probit statistical analysis. The results indicate that investments in both ICT and education enhance the probability of generating new business

Mobile Agents - Smart Messages

TCD-CS-1997-05Wireless communication with Mobile Computing devices is known to be problematic. It is very different in character from conventional communication over wired networks. Since many distributed applications make assumptions about network characteristics, they may not be used in a hostile mobile environment. We are proposing a new kind of messaging system which incorporates adaptive behaviour into the messages themselves. We call these `Smart Messages?, and implement them using Mobile Agents. The metaphor we use is of a message being delivered by a courier (Mobile Agent), on a potentially unresolved route. The `intelligence? is in the messages themselves rather than in the network. The approach taken expands on the self-routing capabilities of current Mobile Agent systems such as Aglets or Telescript. We aim to provide structured support for handling the particular problems associated with wireless communications. These include very limited, variable and asymmetric bandwidth, frequent and prolonged disconnections, geographical mobility and high usage costs. `Smart Messages? offer an efficient, adaptable and robust solution to many of these problems

MultiCasting in an ATM Network

Contents 1. What is Multicast? 2. Why Multicast? 3. ATM & Multicasting basics 4. Extending ATM for Multicasting 5. References 6. Links to other sites with relevant material (on Bryan's page) 7. Glossary of Terms What is Multicast? Multicast can be simply defined as the ability to send one message to one or more nodes in a single operation. This is different than using replicated unicast which sends messages from one node to a group of nodes by sending to each node individually. This will incur one operation for each destination node and is non-atomic. See the IPMulticast main page for a more complete description. Back to top Why Multicast? Distributed Systems & Databases Multicast is often used for synchronisation, duplication and coherency of data in these systems. For the implementation of coherency one needs to use atomic operations among different machines. This atomicity can be achieved by using

MCK: Wireless Communication with Mobile Agents.

TCD-CS-1998-0