Motivation Is Deficient in the Spontaneously Hypertensive Rat (SHR), a Rodent Model of Adhd: Evidence from an Operant Breakpoint Paradigm

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most commonly diagnosed childhood neurobehavioral disorders. ADHD is characterized by three core behavioral deficits (hyperactivity, inattention, and impulsivity) that significantly hinder the daily functioning of those diagnosed. Furthermore, children with ADHD have problems with motivation and often require larger, more frequent rewards in order to complete a task. In this study, we used the Spontaneously Hypertensive Rat (SHR), a rodent model of ADHD that exhibits all the core deficits of the disorder. The goal of the current study was to further validate the SHR as a model of ADHD by training rats in an operant conditioning breakpoint paradigm which is commonly used to assess motivation. Twelve male SHR and 12 male Wistar Kyoto (WKY) control rats were trained on a Progressive Ratio schedule that increased in difficulty until the rats reached their breakpoint, which was defined as the point at which the animals stopped working. The breakpoint served as a measure of motivation and the higher the breakpoint, the more motivated the animal was. Results show that the SHR animals had a significantly lower breakpoint compared to the control animals, indicating that the SHR animals gave up working on the task much sooner. While the etiology of the disorder is largely unknown, we do know that various areas of the brain, including the cerebellum, have abnormalities and warrants further investigation. In the current study, the dentate nucleus, one the three deep nuclei of the cerebellum, was examined as it has previously been shown to have a role in motivational behavior. Findings indicate that the dentate nucleus volume was smaller in the SHR animals compared to the same structure in WKY rats. It is proposed that the smaller dentate nucleus in SHR rats may contribute to the motivational deficits expressed in these animals

Elementary Excitations of Quantum Critical 2+1 D Antiferromagnets

It has been proposed that there are degrees of freedom intrinsic to quantum critical points that can contribute to quantum critical physics. We point out that this conclusion is quite general below the upper critical dimension. We show that in 2+1 D antiferromagnets skyrmion excitations are stable at criticality and identify them as the critical excitations. We found exact solutions composed of skyrmion and antiskyrmion superpositions, which we call topolons. We include the topolons in the partition function and renormalize by integrating out small size topolons and short wavelength spin waves. We obtain correlation length exponent nu=0.9297 and anomalous dimension eta=0.3381.Comment: 4 page

Arenas de San Pedro y su comarca : Sierra de Gredos

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Dysplasia in perforated intestinal pneumatosis complicating a previous jejuno-ileal bypass: a cautionary note.

We present the case of an elderly woman who devel- oped a bowel perforation related to pneumatosis intes- tinalis, 33 years after a jejuno-ileal bypass for severe obesity. Final histological examination revealed the presence of dysplasia in the resected specimen. On the basis of our case and a review of the literature, we discuss the etiopathogenesis, the clinical aspects and the treatment of this rare condition

POR UMA DEFINIÇÃO DE UM PONTO DE VISTA PERTINENTE E COERENTE NA ANÁLISE DO TEXTO LITERÁRIO

Este trabalho se propõe o exame dos estudos de estilo de L. Spitzer e E. Auerbach, da critica temática de J.P. Richard e J. Rousset e de certas proposições do estruturalismo, numa tentativa de busca de uma interpretação da obra literária orientada para a fusão de textos e contexto

Hechos de la historia contemporánea : apuntes de la Guerra Civil española

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Experimental and computational studies on the formation of cyanate from early metal terminal nitrido ligands and carbon monoxide

An important challenge in the artificial fixation of N[subscript 2] is to find atom efficient transformations that yield value-added products. Here we explore the coordination complex mediated conversion of ubiquitous species, CO and N[subscript 2], into isocyanate. We have conceptually split the process into three steps: (1) the six-electron splitting of dinitrogen into terminal metal nitrido ligands, (2) the reduction of the complex by two electrons with CO to form an isocyanate linkage, and (3) the one electron reduction of the metal isocyanate complex to regenerate the starting metal complex and release the product. These steps are explored separately in an attempt to understand the limitations of each step and what is required of a coordination complex in order to facilitate a catalytic cycle. The possibility of this cyanate cycle was explored with both Mo and V complexes which have previously been shown to perform select steps in the sequence. Experimental results demonstrate the feasibility of some of the steps and DFT calculations suggest that, although the reduction of the terminal metal nitride complex by carbon monoxide should be thermodynamically favorable, there is a large kinetic barrier associated with the change in spin state which can be avoided in the case of the V complexes by an initial binding of the CO to the metal center followed by rearrangement. This mandates certain minimal design principles for the metal complex: the metal center should be sterically accessible for CO binding and the ligands should not readily succumb to CO insertion reactions.National Science Foundation (U.S.) (CHE-1111357

Real-time classification of malicious URLs on Twitter using Machine Activity Data

Massive online social networks with hundreds of millions of active users are increasingly being used by Cyber criminals to spread malicious software (malware) to exploit vulnerabilities on the machines of users for personal gain. Twitter is particularly susceptible to such activity as, with its 140 character limit, it is common for people to include URLs in their tweets to link to more detailed information, evidence, news reports and so on. URLs are often shortened so the endpoint is not obvious before a person clicks the link. Cyber criminals can exploit this to propagate malicious URLs on Twitter, for which the endpoint is a malicious server that performs unwanted actions on the person’s machine. This is known as a drive-by-download. In this paper we develop a machine classification system to distinguish between malicious and benign URLs within seconds of the URL being clicked (i.e. ‘real-time’). We train the classifier using machine activity logs created while interacting with URLs extracted from Twitter data collected during a large global event – the Superbowl – and test it using data from another large sporting event – the Cricket World Cup. The results show that machine activity logs produce precision performances of up to 0.975 on training data from the first event and 0.747 on a test data from a second event. Furthermore, we examine the properties of the learned model to explain the relationship between machine activity and malicious software behaviour, and build a learning curve for the classifier to illustrate that very small samples of training data can be used with only a small detriment to performance

Improvement of Tuberculosis Laboratory Capacity on Pemba Island, Zanzibar: A Health Cooperation Project.

Low-income countries with high Tuberculosis burden have few reference laboratories able to perform TB culture. In 2006, the Zanzibar National TB Control Programme planned to decentralize TB diagnostics. The Italian Cooperation Agency with the scientific support of the "L. Spallanzani" National Institute for Infectious Diseases sustained the project through the implementation of a TB reference laboratory in a low-income country with a high prevalence of TB. The implementation steps were: 1) TB laboratory design according to the WHO standards; 2) laboratory equipment and reagent supplies for microscopy, cultures, and identification; 3) on-the-job training of the local staff; 4) web- and telemedicine-based supervision. From April 2007 to December 2010, 921 sputum samples were received from 40 peripheral laboratories: 120 TB cases were diagnosed. Of all the smear-positive cases, 74.2% were culture-positive. During the year 2010, the smear positive to culture positive rate increased up to 100%. In March 20, 2010 the Ministry of Health and Social Welfare of Zanzibar officially recognized the Public Health Laboratory- Ivo de Carneri as the National TB Reference Laboratory for the Zanzibar Archipelago. An advanced TB laboratory can represent a low cost solution to strengthen the TB diagnosis, to provide capacity building and mid-term sustainability

Nonlinear effects in tunnelling escape in N-body quantum systems

We consider the problem of tunneling escape of particles from a multiparticle system confined within a potential trap. The process is nonlinear due to the interparticle interaction. Using the hydrodynamic representation for the quantum equations of the multiparticle system we find the tunneling rate and time evolutions of the number of trapped particles for different nonlinearity values.Comment: 10 pages, 3 figure