To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
It is known that 12C beam transmission through the accelerator decreases at high beam currents. This effect depends on machine design and varies across different types of AMS instruments. For beam currents of about 100 μA, the effect is small on the 500 kV tandem CAMS unit, whereas beam saturation is observed for similar high beam currents on the 250 kV SSAMS unit. While this effect is very evident for high 12C beam currents, we have also observed that even the 13C beam is found to suffer modest transmission loss with beam current. As a result, the 13C/12C ratio does not remain constant with beam current. By correcting for the effects of 12C beam saturation and decreased 13C transmission, we have obtained online δ13C values that are more accurate and precise at moderately high beam currents for SSAMS.
Background: Essential tremor (ET) is reported to have a bimodal distribution of age at onset (AAO) with phenotypic variability based on the AAO. This study aims to explore the distribution of AAO based on mathematical modeling and ascertain the differences, if any, in the clinical features of groups. Methods: A chart review was conducted for 252 patients with ET diagnosed based on the Consensus statement of the Movement Disorder Society on Tremor. Finite mixture modeling was performed to identify groups of the cohort based on the AAO. Results: Three groups were defined: early onset (EO): AAO ≤ 22 years, n = 63, intermediate onset (IO): 23 ≤ AAO ≤ 35 years, n = 43, and late onset (LO): AAO ≥ 36 years, n = 146. There were no significant differences related to family history or responsiveness to alcohol. The EO group had significantly higher prevalence of upper limb and lower limb tremor. Head tremor and voice tremor was more prevalent in the IO and LO groups. Cerebellar signs showed a significant increase with an increase in AAO. Conclusions: ET shows significant phenotypic variability based on the AAO. Patients with an early AAO are more likely to develop an appendicular tremor, whereas the probability of axial tremor and cerebellar signs increases with increasing AAO.
The burden of dengue virus infections increased globally during recent years. Though India is considered as dengue hyper-endemic country, limited data are available on disease epidemiology. The present study includes molecular characterization of dengue virus strains occurred in Hyderabad, India, during the year 2014. A total of 120 febrile cases were recruited for this study, which includes only children and 41 were serologically confirmed for dengue positive infections using non-structural (NS1) and/or IgG/IgM ELISA tests. RT-PCR, nucleotide sequencing and evolutionary analyses were carried out to identify the circulating serotypes/genotypes. The data indicated a high percent of severe dengue (63%) in primary infections. Simultaneous circulation of all four serotypes and co-infections were observed for the first time in Hyderabad, India. In total, 15 patients were co-infected with more than one dengue serotype and 12 (80%) of them had severe dengue. One of the striking findings of the present study is the identification of serotype Den-1 as the first report from this region and this strain showed close relatedness to the Thailand 1980 strains but not to any of the strains reported from India until now. Phylogenetically, all four strains of the present study showed close relatedness to the strains, which are reported to be high virulent.
The influence of temperature-dependent fluid properties on flow and heat transfer of an electrically conducting fluid over a stretching sheet with variable thickness in the presence of a transverse magnetic field is analyzed. Using similarity transformations, the governing coupled non-linear partial differential equations (momentum and energy equations) are transformed into a system of coupled non-linear ordinary differential equations and are solved numerically by Keller-box method. For increasing values of the wall thickness parameter, the analysis reveals quite interesting flow and heat transfer patterns. The effects of the temperature dependent viscosity, the wall velocity power index, the thermal conductivity, the wall temperature parameter and the Prandtl number on the flow and temperature fields are presented. The obtained numerical results are compared with the available results in the literature for some special cases and are found to be in excellent agreement. The skin friction and the wall temperature gradient are presented for different values of the physical parameters and the salient features are analyzed.
Radiocarbon was measured in the surface seawater dissolved inorganic carbon (DIC) of the Bay of Bengal during November 2006. A meridional transect of the Δ14C in DIC was obtained from measurements in closely spaced samples collected roughly along 88°E. The Δ14C of these samples ranged from 44‰ to 57.7‰ (mean 51.8 ± 1.1‰, n = 12), and 38‰ at one station in the northern Bay of Bengal. The overall pattern of 14C distribution in DIC of surface Bay of Bengal during 2006 was roughly similar to that during the WOCE expedition of 1995. These results indicate a Δ14C decline rate of ∼4‰ per decade since WOCE in the surface Bay of Bengal, which is much smaller compared to a decline rate of ∼25‰ per decade observed in the 2 decades between the GEOSECS and WOCE expeditions, due to the smaller atmosphere-ocean Δ14C gradient.
A new 250kV single stage AMS accelerator (SSAMS) was installed at the Center for Applied Isotope Studies, University of Georgia. The accelerator is intended to be used primarily for radiocarbon measurements of natural and biobased samples, while all other samples such as marine, geological, atmospheric and archaeological samples are measured on the decade-old 500kV compact tandem accelerator (CAMS). The new AMS system is equipped with a 134-cathode MC-SNICS ion source. In this article, we show the results of the tests carried out on standards and blanks and compare the performance of the new machine with that of the CAMS unit. We have also compared the stable isotope data from AMS measurements to the conventional isotope ratio mass spectrometers (IRMS) data.
Radiocarbon and stable isotope determination in foods, flavors, and beverages, for the authentication of source material and process of formation, is a well-established method of identity used in industry. New methods of provenance determination, using stable isotopes of oxygen and hydrogen, have added to the host of other isotopic methods used for characterizing natural or botanically derived products. The unambiguous determinant of a product's fossil fuel origin be it from petroleum, natural gas, or coal, is through the measurement of its 14C content. The 14C content can also be used to determine the fraction dilution of recently grown and harvested material with that derived from fossil fuel, and even confirms the vintage of agricultural products based on the well-established decrease of bomb-produced atmospheric 14C. This paper documents 14C measurements at the University of Georgia's Center for Applied Isotope Studies accelerator mass spectrometry and stable isotope laboratories, over the last 3 yr, for 10 important flavoring compounds. By establishing an accurate and current level of 14C in botanically derived products, we were able to confirm a particular source for vanilla production, the most popular consumer flavor in the marketplace. Over the years, vanilla extract has been produced less and less from vanilla beans (Vanilla planifolia), particularly those from Madagascar and the Comoros Islands, and more from other botanical precursors such as ferulic acid, clove oil, and guaiacol. We report isotopic data to support this precursor for vanilla production based on high 14C levels accumulated during the tree's life, incorporated in the tree rings and their associated stable isotope abundances.
Biomineralization is the process by which living organisms orchestrate the synthesis and organization of minerals (biominerals), and it may be viewed as an ancient process for accumulation of metal ions in living systems. The structure and properties of biominerals have yet to be rivaled by any synthetic effort by scientists to date. Therefore, deciphering the assembly algorithms and the components that initiate and promote hierarchical deposition of cations has significant implications for the development of nanocomposites and nanotechnology as a whole. This issue of MRS Bulletin highlights some of the challenges in characterizing and replicating the biomineralization processes, and the role of non-collagenous proteins in the biomineralization process.
An analysis is carried out to study the magnetohydrodynamic (MHD) flow and heat transfer characteristics of an electrically conducting dusty non-Newtonian fluid, namely, the upper convected Maxwell (UCM) fluid over a stretching sheet. The stretching velocity and the temperature at the surface are assumed to vary linearly with the distance from the origin. Using a similarity transformation, the governing nonlinear partial differential equations of the model problem are transformed into coupled non-linear ordinary differential equations and the equations are solved numerically by a second order finite difference implicit method known as the Keller-box method. Comparisons with the available results in the literature are presented as a special case. The effects of the physical parameters on the fluid velocity, the velocity of the dust particle, the density of the dust particle, the fluid temperature, the dust-phase temperature, the skin friction, and the wall-temperature gradient are presented through tables and graphs. It is observed that, Maxwell fluid reduces the wall-shear stress. Also, the fluid particle interaction reduces the fluid temperature in the boundary layer. Furthermore, the results obtained for the flow and heat transfer characteristics reveal many interesting behaviors that warrant further study on the non-Newtonian fluid flow phenomena, especially the dusty UCM fluid flow phenomena.
In this paper, a numerical study is carried out to investigate the mixed convection flow and heat transfer in a parallel-plate channel with an anisotropic permeable porous medium. The principal axis of the porous medium is orientated in a direction which is oblique to the gravity vector. Both clear (Newtonian) fluid dissipation and Darcy viscous dissipation are considered in the heat transport equation. In this model, the temperature dependent fluid properties are considered and their influence on the flow and heat transfer characteristics is brought out. The governing non-linear equations (in non-dimensional form) are solved numerically by a second order finite difference scheme. The directional permeability ratio A1 is defined to combine the effects of the permeability ratio parameter K* = (K1 / K2) and the orientation angle Φ1. The effects of the anisotropic permeability ratio, the orientation angle of the principal axis, and the temperature dependent variable properties on the mixed convection flow and heat transfer are investigated. It is demonstrated that both the anisotropic permeability of the porous medium and the variable transport properties have strong effects on the flow and heat transfer characteristics.
To obtain insights into disaster management among dental graduates in a dental institute in India.
A total of 103 of 104 house surgeons in Shri Dharmasthala Manjunatheswar College of Dental Sciences and Hospital, Dharwad, participated in the main study (response rate = 99.04%). Their knowledge, attitude, and behavior regarding disaster management were assessed by use of a survey questionnaire. Information was also collected regarding age, gender, religion, and residence.
Mean knowledge, attitude, and behavior scores toward disaster management were 45.46%, 79.53%, and 37.70%, respectively. A significant relationship was observed between knowledge and attitude scores (r = 0.248, P = .012). No significant differences were found in knowledge, attitude, and behavior by gender, religion, and residence. Religion was a significant predictor of knowledge scores (χ2 = 10.108, P = .006).
Respondents had favorable attitudes toward disaster management, but their knowledge and behavior required considerable improvement. Knowledge of the respondents was significantly associated with their attitude. This pilot study highlights the need for curriculum changes in dental education in India and further nationwide study. (Disaster Med Public Health Preparedness. 2014;0:1-7)
To assess subjective preference using three nasal hygiene systems: Stérimar Original®, Emcur® and Sinus Rinse™.
We used a prospective, single-blind, randomised, crossover study to compare three nasal hygiene systems: Stérimar Original, Emcur and Sinus Rinse.
Eighteen adult volunteers were recruited and were asked to rate their experience over three days using three well-established nasal hygiene systems. A standard visual analogue scale was used to assess five criteria: (1) simplicity of instructions; (2) ease of use; (3) comfort; (4) perceived nasal clearance (effectiveness) and (5) single best overall system.
Stérimar Original was found to have the easiest instructions to understand compared to the other two systems. There was no significant difference between Stérimar Original and Sinus Rinse with regards to ease of use but they were both significantly easier to use than Emcur (p < 0.05). There was no statistically significant difference between the three systems when comparing the last three criteria. There was no alteration in preference when the cost of each treatment was disclosed to the subjects, and no significant side effects were reported.
The instructions accompanying Stérimar Original appeared to be the easiest to understand, while Stérimar Original and Sinus Rinse were easier to use than Emcur.
This chapter will discuss body perfusion MRI applications, specifically related to three organs: kidneys, liver, and lungs. Each section begins with a short description of the scientific and/or clinical rationale for perfusion imaging and then describes what is known to date regarding the feasibility and/or status of performing these measurements, along with their potential significance. Unlike neurological and oncological applications described in Chapters 8–13, perfusion MRI in the body is still evolving, and so no specific, standardized methods of data acquisition and analysis have yet emerged. However, a brief description of all methods available to date and relevant references are provided. The perfusion MRI techniques discussed fall under two primary categories, either those based on exogenous contrast agent administration, or those based on endogenous contrast mechanisms.
In 1938, Goldblatt [1, 2] demonstrated a relationship between hypertension and renal ischemia. He was able to consistently produce elevations in systolic blood pressure by producing renal ischemia with a constricting clamp in an animal model. Removal of the clamp restored blood pressure to the reference range. Based on this finding, Burkland et al. performed nephrectomy of a unilateral ischemic kidney as a cure for hypertension . This remained the method of surgical treatment until 1960 when Lambeth et al. reported resolving hypertension by correction of renal artery stenosis (RAS) . In the 1960s, the delineation of the renin–angiotensin system and its relation to hypertension  also had a large impact on the medical therapy and diagnostic studies used in renovascular hypertension.
Herpes virus infections can cause cognitive impairment during and after acute encephalitis. Although chronic, latent/persistent infection is considered to be relatively benign, some studies have documented cognitive impairment in exposed persons that is untraceable to encephalitis. These studies were conducted among schizophrenia (SZ) patients or older community dwellers, among whom it is difficult to control for the effects of co-morbid illness and medications. To determine whether the associations can be generalized to other groups, we examined a large sample of younger control individuals, SZ patients and their non-psychotic relatives (n=1852).
Using multivariate models, cognitive performance was evaluated in relation to exposures to herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2) and cytomegalovirus (CMV), controlling for familial and diagnostic status and sociodemographic variables, including occupation and educational status. Composite cognitive measures were derived from nine cognitive domains using principal components of heritability (PCH). Exposure was indexed by antibodies to viral antigens.
PCH1, the most heritable component of cognitive performance, declines with exposure to CMV or HSV-1 regardless of case/relative/control group status (p = 1.09 × 10−5 and 0.01 respectively), with stronger association with exposure to multiple herpes viruses (β = −0.25, p = 7.28 × 10−10). There were no significant interactions between exposure and group status.
Latent/persistent herpes virus infections can be associated with cognitive impairments regardless of other health status.
A numerical study is carried out to study the effects of variable fluid properties on the boundary layer flow and heat transfer of a nanofluid at a flat sheet. The effects of Brownian motion, thermophoresis and viscous dissipation due to frictional heating are also considered. The temperature-dependent variable fluid properties, namely, the fluid viscosity and the thermal conductivity are assumed to vary, respectively, as an inverse function and a linear function of temperature. Using a similarity transformation, the governing non-linear partial differential equations of the model problem are transformed into coupled non-linear ordinary differential equations and these equations are solved numerically by Keller-Box method. Velocity, temperature, and nanoparticles volume fraction profiles are presented and analyzed for several sets of values of the governing parameters; namely, variable fluid viscosity, variable thermal conductivity, Brownaian motion, thermophoresis and plate-velocity parameters with changes in the Prandtl and Schmidt numbers. It is observed that there is an increase in the skin friction in the upstream movement of the plate: But quite the opposite is true in the downstream movement of the plate. Also, the effect of the Schmidt number and the Brownian motion parameter is to reduce the Sherwood number, where as the effect of thermophoresis parameter is to enhance it.
During a survey of edible Crustacea for recovery of infective stages (metacercariae) of potential helminthozoonoses of trematode origin in north-east India, the crab species Barytelphusa lugubris mansoniana, collected from suspected foci of lungfluke infection in Meghalaya and Assam, was found to harbour metacercarial cysts that were different from the earlier reported infection, in which the lungfluke Paragonimus was confirmed to be implicated. Using morphological criteria, this metacercaria was identified as Microphallus indicus Mukherjee & Ghosh, 1967 of the trematode family Microphallidae. The present study extends the previous work by providing molecular characterization of this parasite using ribosomal internal transcribed spacer regions (rDNA ITS1 and ITS2) and the partial large ribosomal subunit DNA, lsr. These target regions were amplified by polymerase chain reaction (PCR) using trematode universal primers and sequenced. In BLAST analysis the query sequences were found close to members of Microphallidae and closest to the genus Microphallus.
Crystals of N-acetyl-L-cysteine have been grown by slow evaporation solution growth technique using water as solvent. Cell parameters of the crystals were confirmed by powder X-ray diffraction. Functional groups were identified and their vibrational activity was studied by investigating the FTIR spectrum. Decomposition nature of the grown material was studied in thermal analysis. Transparent nature of the crystal in UV-VIS-NIR region was examined by optical absorption spectrum. Frequency conversion process was tested and the title crystal has two times larger relative second harmonic conversion efficiency compared to the standard KDP. Static and dynamic values of first-order hyperpolarizability were calculated and also the electronic excitation mechanism was analyzed.