Motivation

The ability of humans and animals to survive in a constantly changing environment is a testament to the power of biological processes. At any given instant in our lives, we are faced with an enormous number of sensory stimuli, and we can typically generate an equally large number of behaviors. How do we learn to ignore irrelevant information and suppress inappropriate behavior so that we may function in a complex environment? In this chapter we discuss motivation, the internal force that produces actions reflecting the interactions between our needs and the demands of our environment. We will first discuss what psychologists mean when they refer to motivation, and then review neural network theories that can expbin how motivation arises within biological nervous systems.Sloan Fellowship (BR-3122): Air Force Office of Scientific Research (F49620-92-J-0499, F49620-92-J-0334

Systemic MMP inhibition for periodontal wound repair: results of a multi-centre randomized-controlled clinical trial

Aim : This multi-centre, prospective, controlled trial was designed to examine the biological response of the matrix metalloproteinase(MMP) inhibitor subantimicrobial dose doxycycline (SDD) combined with access flap surgery on periodontal wound repair in patients with chronic severe periodontitis. Material and Methods : Seventy subjects were enrolled into a 12-month, randomized, placebo-controlled, double-masked trial to evaluate disease response to 6 months therapy and “wash-out” of either placebo+surgery or SDD (20 mg b.i.d.)+surgery. Primary outcome measure included clinical attachment levels (CAL) and secondary outcomes included probing depth (PD), bleeding on probing (BOP), as well as gingival crevicular fluid bone marker assessment [collagen telopeptides (ICTP)]. These measurements were taken at baseline through 12 months post-surgery and drug administration. Results : Patients treated with SDD and surgery demonstrated stronger reductions in PD in surgically-treated sites of ges;7 mm as well as gains in CAL ( p <0.004). Furthermore, SDD+surgery resulted in short-term reductions in ICTP levels compared with placebo. Rebounds in ICTP levels and clinical parameters occurred when SDD was withdrawn. Conclusions : The results from this multi-centre study suggests that SDD in combination with surgery improves the short-term response of periodontal therapy by reducing PD, increasing CAL gain and inhibiting early stage bone resorption.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75470/1/j.1600-051X.2008.01351.x.pd

Performance characteristics of the Cepheid Xpert MTB/RIF test in a tuberculosis prevalence survey.

BACKGROUND: Xpert MTB/RIF ("Xpert") is a molecular test for detection of Mycobacterium tuberculosis (MTB) in sputum. Performance characteristics have been established for its use during passive tuberculosis (TB) case detection in symptomatic TB suspects, but Xpert performance has not been assessed in other settings. Objectives were to determine Xpert performance and costs in the context of a TB prevalence survey. METHODOLOGY/PRINCIPAL FINDINGS: This was a diagnostic sub-study of a TB prevalence survey conducted in gold mining companies in South Africa. Sputa (one per participant) were tested using smear microscopy, liquid culture (reference comparator), and Xpert. Costs were collected using an ingredients approach and analyzed using a public health program perspective. 6893 participants provided a sputum specimen. 187/6893 (2.7%) were positive for MTB in culture, 144/6893 (2.1%) were positive for MTB by Xpert, and 91/6893 (1.3%) were positive for acid fast bacilli by microsocopy. Sensitivity, specificity, positive predictive value, and negative predictive value for detection of MTB by Xpert were 62.6% (95% confidence interval [CI] 55.2, 69.5), 99.6% (99.4, 99.7), 81.3% (73.9, 87.3), and 98.9 (98.6, 98.8); agreement between Xpert and culture was 98.5% (98.2, 98.8). Sensitivity of microscopy was 17.6% (12.5, 23.9). When individuals with a history of TB treatment were excluded from the analysis, Xpert specificity was 99.8 (99.7, 99.9) and PPV was 90.6 (83.3, 95.4) for detection of MTB. For the testing scenario of 7000 specimens with 2.7% of specimens culture positive for MTB, costs were $165,690 for Xpert and$115,360 for the package of microscopy plus culture. CONCLUSION: In the context of a TB prevalence survey, the Xpert diagnostic yield was substantially higher than that of microscopy yet lower than that of liquid culture. Xpert may be useful as a sole test for TB case detection in prevalence surveys, particularly in settings lacking capacity for liquid culture

The dynamical formation of LMXBs in dense stellar environments: globular clusters and the inner bulge of M31

The radial distribution of luminous L_X>10^{36} erg/s X-ray point sources in the bulge of M31 is investigated using archival Chandra observations. We find a significant increase of the specific frequency of X-ray sources, per unit stellar mass, within 1 arcmin from the centre of the galaxy. The radial distribution of surplus sources in this region follows the density squared law, suggesting that they are low-mass X-ray binaries formed dynamically in the dense inner bulge. We investigate dynamical formation of LMXBs, paying particular attention to the high velocity regime characteristic for galactic bulges, which has not been explored previously. Our calculations suggest that the majority of the surplus sources are formed in tidal captures of black holes by main sequence stars of low mass, M<0.3-0.4 M_sol, with some contribution of NS systems of same type. Due to the small size of the accretion discs a fraction of such systems may be persistent X-ray sources. Some of sources may be ultra-compact X-ray binaries with helium star/white dwarf companions. We also predict a large number of faint transients, both NS and BH systems, within 1 arcmin from the M31 galactic centre. Finally, we consider the population of dynamically formed binaries in Galactic globular clusters, emphasizing the differences between these two types of stellar environmentsComment: 18 pages, published in MNRA

Practical dyspnea assessment: relationship between the 0–10 numerical rating scale and the four-level categorical verbal descriptor scale of dyspnea intensity

Context—Measurement of dyspnea is important for clinical care and research. Objectives—To characterize the relationship between the 0–10 Numerical Rating Scale (NRS) and four-level categorical Verbal Descriptor Scale (VDS) for dyspnea assessment. Methods—This was a substudy of a double-blind randomized controlled trial comparing palliative oxygen to room air for relief of refractory breathlessness in patients with life-limiting illness. Dyspnea was assessed with both a 0–10 NRS and a four-level categorical VDS over the one-week trial. NRS and VDS responses were analyzed in cross section and longitudinally. Relationships between NRS and VDS responses were portrayed using descriptive statistics and visual representations. Results—Two hundred twenty-six participants contributed responses. At baseline, mild and moderate levels of breathlessness were reported by 41.9% and 44.6% of participants, respectively. NRS scores demonstrated increasing mean and median levels for increasing VDS intensity, from a mean (SD) of 0.6 (±1.04) for VDS none category to 8.2 (1.4) for VDS severe category. The Spearman correlation coefficient was strong at 0.78 (P < 0.0001). Based on the distribution of NRS scores within VDS categories, we calculated test characteristics of two different cutpoint models. Both models yielded 75% correct translations from NRS to VDS; however, Model A was more sensitive for moderate or greater dyspnea, with fewer misses downcoded. Conclusion—There is strong correlation between VDS and NRS measures for dyspnea. Proposed practical cutpoints for the relationship between the dyspnea VDS and NRS are 0 for none, 1–4 for mild, 5–8 for moderate, and 9–10 for severe

Natural occurrence of Cucumber mosaic virus infecting water mint (Mentha aquatica) in Antalya and Konya, Turkey

A virus causing a disease in mint (the aromatic and culinary plant) has recently become a problem in the Taurus Mountains, a mountain range in the Mediterranean region of Turkey. To detect the virus and investigate its distribution in the region, mint leaf samples were collected from the vicinity of spring areas in the plateaus of Antalya and Konya in 2009. It was found that Cucumber mosaic virus (CMV) was detected in 27.08% of symptomatic samples tested by DAS-ELISA. To the best of our knowledge, this is the first report of CMV on mint plants in this region of Turkey

Malaria in pregnancy.

Recently, there has been a resurgence of malaria in densely populated areas of the United States secondary to human migration from endemic areas where factors such as cessation of vector control, vector resistance to insecticides, disease resistance to drugs, environmental changes, political instability, and indifference, have played a role for malaria becoming an overwhelming infection of these tropical underdeveloped countries. It is important for health care providers of gravida to be alert of the disease and its effects on pregnancy

A Class Representative Model for Pure Parsimony Haplotyping under Uncertain Data

The Pure Parsimony Haplotyping (PPH) problem is a NP-hard combinatorial optimization problem that consists of finding the minimum number of haplotypes necessary to explain a given set of genotypes. PPH has attracted more and more attention in recent years due to its importance in analysis of many fine-scale genetic data. Its application fields range from mapping complex disease genes to inferring population histories, passing through designing drugs, functional genomics and pharmacogenetics. In this article we investigate, for the first time, a recent version of PPH called the Pure Parsimony Haplotype problem under Uncertain Data (PPH-UD). This version mainly arises when the input genotypes are not accurate, i.e., when some single nucleotide polymorphisms are missing or affected by errors. We propose an exact approach to solution of PPH-UD based on an extended version of Catanzaro et al. [1] class representative model for PPH, currently the state-of-the-art integer programming model for PPH. The model is efficient, accurate, compact, polynomial-sized, easy to implement, solvable with any solver for mixed integer programming, and usable in all those cases for which the parsimony criterion is well suited for haplotype estimation

Measurement of the Atmospheric Muon Charge Ratio at TeV Energies with MINOS

The 5.4 kton MINOS far detector has been taking charge-separated cosmic ray muon data since the beginning of August, 2003 at a depth of 2070 meters-water-equivalent in the Soudan Underground Laboratory, Minnesota, USA. The data with both forward and reversed magnetic field running configurations were combined to minimize systematic errors in the determination of the underground muon charge ratio. When averaged, two independent analyses find the charge ratio underground to be 1.374 +/- 0.004 (stat.) +0.012 -0.010(sys.). Using the map of the Soudan rock overburden, the muon momenta as measured underground were projected to the corresponding values at the surface in the energy range 1-7 TeV. Within this range of energies at the surface, the MINOS data are consistent with the charge ratio being energy independent at the two standard deviation level. When the MINOS results are compared with measurements at lower energies, a clear rise in the charge ratio in the energy range 0.3 -- 1.0 TeV is apparent. A qualitative model shows that the rise is consistent with an increasing contribution of kaon decays to the muon charge ratio.Comment: 16 pages, 17 figure