Epidemiological model for Clostridium difficile transmission in healthcare settings

OBJECTIVE: Recent outbreaks of Clostridium difficile infection (CDI) have been difficult to control, and data indicate the importance of different sources of transmission may have changed. Our objectives were to evaluate the contributions of asymptomatic and symptomatic C. difficile carriers to new colonizations and to determine the most important epidemiological factors influencing C. difficile transmission. DESIGN: Retrospective cohort SETTING AND PATIENTS: All patients admitted to medical wards at a large tertiary care hospital in the US from Jan 1 to Dec 31, 2008. METHODS: Data from six medical wards and published literature were used to develop a compartmental model of C. difficile transmission. Patients could be in one of five transition states in the model: resistant to colonization (R), susceptible to colonization (S), asymptomatically colonized without protection against CDI (C(−)), asymptomatically colonized with protection against CDI (C(+)), and patients with CDI (D). RESULTS: The contributions of C(−), C(+) and D patients to new colonizations were similar. The simulated basic reproduction number ranged from .55 to 1.99, with median 1.04. These values suggest that transmission within the ward alone from patients with CDI cannot sustain new C. difficile colonizations, and therefore, the admission of colonized patients plays an important role in sustaining transmission in the ward. The epidemiological parameters that ranked as the most influential were the proportion of admitted C(−) and the transmission coefficient for asymptomatic carriers. CONCLUSION: Our study underscores the need to further evaluate the role of asymptomatically colonized patients in C. difficile transmission in the healthcare setting

Interaction kernels for A = 4n binary cluster systems

Bargmann transform techniques used to calculate norm kernels for nuclear cluster systems have been generalized to evaluate interaction kernels for central interactions of gaussian form for binary cluster systems made up of SU(4)-scalar (A = 4n) cluster fragments with internal functions of good SU(3) symmetry and equal oscillator width parameters. The technique involves a reduction from A-particle orbital states of space symmetry characterized by 4-columned Young tableaux to states of single-column symmetry. The interaction kernels are built partly through a convolution of the single-column Bargmann transforms of the Fourier components of basic one-body operators. Bargmann transforms of single-column type have been evaluated in algebraic form for a two-body gaussian interaction and for the one-body Fourier kernel, [Sigma]jexp (iq [middle dot] rj). for the following A-particle systems and cluster decompositions: A = 12, [alpha] + 8Be; A = 16, [alpha] + 12C, 8Be + 8Be; A = 20, [alpha] + 16O, 8Be + 12C; and A = 24, 12C + 12C, 8Be + 16O, [alpha] + 20Ne. The construction of the Bargmann transform for the full A-particle system is illustrated with a simple example. The example also shows how the coordinate space matrix elements needed for the evaluation of RGM and GCM kernels can be extracted from appropriate expansions of this Bargmann transform by purely algebraic techniques.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23954/1/0000201.pd

Spectroscopic amplitudes for complex cluster systems

By expanding the Bargmann-Segal integral transform of nomi and overlap kernels in appropriately SU(3) coupled Bargmann space functions, the calculation of norm and overlap matrix elements in a cluster model basis is reduced to purely algebraic techniques involving the algebra of SU(3) recoupling transformations. This technique has been further developed to make calculations possible for systems of two heavy fragments other than closed-shell nuclei. In one application of the method, analytic expressions are given for the norms of binary fragment systems in which a light fragment of mass number [function of (italic small f)], [function of (italic small f)] [les] 4, is combined with a heavy fragment of mass number A-[function of (italic small f)], with A-[function of (italic small f)] [les] 24. The A-[function of (italic small f)] fragment nuclei with different p- and sd-shell structure illustrate somewhat different problems in the recoupling technique. In a second application, spectroscopic amplitudes are calculated for the most important open channels of the 12C+ 12C resonances. Eigenvalues and eigenvectors of the antisymmetrizer are evaluated in a "molecular basis" of the 12C + 12C system, in which each 12C nucleus is assumed to have SU(3) symmetry (04) with internal rotational excitations of 0+,2+ and 4+. Reduced width amplitudes are calculated connecting such normalized, fully antisymmetrized molecular basis states to exit channels which include: [alpha]+20Ne with 20Ne internal functions of (80) SU(3) symmetry, (K = 0+ band, and (82) SU(3) symmetry, (K = 2- band); 16O+8Be; and 23Na+p or 23Mg+n fragments with 23Na or 23Mg excitations in rotational bands of SU(3) symmetry (83).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24425/1/0000696.pd

Implanted Reuptake-deficient or Wild-type Dopaminergic Neurons Improve ON L-dopa Dyskinesias Without OFF-dyskinesias in a Rat Model of Parkinson's Disease

OFF-L-dopa dyskinesias have been a surprising side-effect of intrastriatal foetal ventral mesencephalic transplantation in patients with Parkinson's disease. It has been proposed that excessive and unregulated dopaminergic stimulation of host post-synaptic striatal neurons by the grafts could be responsible for these dyskinesias. To address this issue we transplanted foetal dopaminergic neurons from mice lacking the dopamine transporter (DATKO) or from wild-type mice, into a rat model of Parkinson's disease and L-dopa-induced dyskinesias. Both wild-type and DATKO grafts reinnervated the host striatum to a similar extent, but DATKO grafts produced a greater and more diffuse increase in extra-cellular striatal dopamine levels. Interestingly, grafts containing wild-type dopaminergic neurons improved parkinsonian signs to a similar extent as DATKO grafts, but provided a more complete reduction of L-dopa induced dyskinesias. Neither DATKO nor wild-type grafts induced OFF-L-dopa dyskinesias. Behavioural and receptor autoradiography analyses demonstrated that DATKO grafts induced a greater normalization of striatal dopaminergic receptor supersensitivity than wild-type grafts. Both graft types induced a similar downregulation and normalization of PEnk and fosb/Δfosb in striatal neurons. In summary, DATKO grafts causing high and diffuse extra-cellular dompamine levels do not per se alter graft-induced recovery or produce OFF-L-dopa dyskinesias. Wild-type dopaminergic neurons appear to be the most effective neuronal type to restore function and reduce L-dopa-induced dyskinesias

Ferromagnetic Liquid Thin Films Under Applied Field

Theoretical calculations, computer simulations and experiments indicate the possible existence of a ferromagnetic liquid state, although definitive experimental evidence is lacking. Should such a state exist, demagnetization effects would force a nontrivial magnetization texture. Since liquid droplets are deformable, the droplet shape is coupled with the magnetization texture. In a thin-film geometry in zero applied field, the droplet has a circular shape and a rotating magnetization texture with a point vortex at the center. We calculate the elongation and magnetization texture of such ferromagnetic thin film liquid droplet confined between two parallel plates under a weak applied magnetic field. The vortex stretches into a domain wall and exchange forces break the reflection symmetry. This behavior contrasts qualitatively and quantitatively with the elongation of paramagnetic thin films.Comment: 10 pages, 4 figures, Submitted to Phys. Rev.

Флуориметрическая методика оценки влияния доксорубицина на жизнеспособность лактобактерий

Объектами исследования являются лекарственные препараты "Лактобактерин" и "Доксорубицин". Цель работы заключается в разработке флуориметрической методики оценки влияния доксорубицина на жизнеспособность лактобактерий. В результате исследования разработана флуориметрическая методика оценки влияния доксорубицина на лактобактерии.The object of study are drugs "Lactobacterin" and "Doxorubicin". The purpose of the work is to develop a fluorimetric methodology for assessing the effect of doxorubicin on the viability of lactobacillus. As a result of the study, a fluorimetric method for assessing the effect of doxorubicin on the viability of lactobacillus

Inhomogeneous magnetization in dipolar ferromagnetic liquids

At high densities fluids of strongly dipolar spherical particles exhibit spontaneous long-ranged orientational order. Typically, due to demagnetization effects induced by the long range of the dipolar interactions, the magnetization structure is spatially inhomogeneous and depends on the shape of the sample. We determine this structure for a cubic sample by the free minimization of an appropriate microscopic density functional using simulated annealing. We find a vortex structure resembling four domains separated by four domain walls whose thickness increases proportional to the system size L. There are indications that for large L the whole configuration scales with the system size. Near the axis of the mainly planar vortex structure the direction of the magnetization escapes into the third dimension or, at higher temperatures, the absolute value of the magnetization is strongly reduced. Thus the orientational order is characterized by two point defects at the top and the bottom of the sample, respectively. The equilibrium structure in an external field and the transition to a homogeneous magnetization for strong fields are analyzed, too.Comment: 17 postscript figures included, submitted to Phys. Rev.

Poor glycaemic control is associated with reduced exercise performance and oxygen economy during cardio-pulmonary exercise testing in people with type 1 diabetes

BackgroundTo explore the impact of glycaemic control (HbA1c) on functional capacity during cardio-pulmonary exercise testing in people with type 1 diabetes.MethodsSixty-four individuals with type 1 diabetes (age: 34 ± 8 years; 13 females, HbA1c: 7.8 ± 1% (62 ± 13 mmol/mol), duration of diabetes: 17 ± 9 years) performed a cardio-pulmonary cycle ergometer exercise test until volitional exhaustion. Stepwise linear regression was used to explore relationships between HbA1c and cardio-respiratory data with p ≤ 0.05. Furthermore, participants were divided into quartiles based on HbA1c levels and cardio-respiratory data were analysed by one-way ANOVA. Multiple regression analysis was performed to explore the relationships between changes in time to exhaustion and cardio-respiratory data. Data were adjusted for confounder.ResultsHbA1c was related to time to exhaustion and oxygen consumption at the power output elicited at the sub-maximal threshold of the heart rate turn point (r = 0.47, R2 = 0.22, p = 0.03). Significant differences were found at time to exhaustion between QI vs. QIV and at oxygen consumption at the power output elicited at the heart rate turn point between QI vs. QII and QI vs. QIV (p < 0.05). Changes in oxygen uptake, power output and in oxygen consumption at the power output elicited at the heart rate turn point and at maximum power output explained 55% of the variance in time to exhaustion (r = 0.74, R2 = 0.55, p < 0.01).ConclusionsPoor glycaemic control is related to less economical use of oxygen at sub-maximal work rates and an earlier time to exhaustion during cardio-pulmonary exercise testing. However, exercise training could have the same potential to counteract the influence of poor glycaemic control on functional capacity

Effects of aversive odour presentation on inhibitory control in the Stroop colour-word interference task

<p>Abstract</p> <p>Background</p> <p>Due to the unique neural projections of the olfactory system, odours have the ability to directly influence affective processes. Furthermore, it has been shown that emotional states can influence various non-emotional cognitive tasks, such as memory and planning. However, the link between emotional and cognitive processes is still not fully understood. The present study used the olfactory pathway to induce a negative emotional state in humans to investigate its effect on inhibitory control performance in a standard, single-trial manual Stroop colour-word interference task. An unpleasant (H₂S) and an emotionally neutral (Eugenol) odorant were presented in two separate experimental runs, both in blocks alternating with ambient air, to 25 healthy volunteers, while they performed the cognitive task.</p> <p>Results</p> <p>Presentation of the unpleasant odorant reduced Stroop interference by reducing the reaction times for incongruent stimuli, while the presentation of the neutral odorant had no effect on task performance.</p> <p>Conclusions</p> <p>The odour-induced negative emotional state appears to facilitate cognitive processing in the task used in the present study, possibly by increasing the amount of cognitive control that is being exerted. This stands in contrast to other findings that showed impaired cognitive performance under odour-induced negative emotional states, but is consistent with models of mood-congruent processing.</p