Temperature measurement and stabilization in a birefringent whispering gallery mode resonator

Temperature measurement with nano-Kelvin resolution is demonstrated at room temperature, based on the thermal dependence of an optical crystal anisotropy in a high quality whispering gallery mode resonator. As the resonator's TE and TM modes frequencies have different temperature coefficients, their differential shift provides a sensitive measurement of the temperature variation, which is used for active stabilization of the temperature.

Resolution of HLA class I sequence-based typing ambiguities by group-specific sequencing primers

The increasing demand for allele-level human leukocyte antigen (HLA) typing has led the sequence-based typing (SBT) to become the preferred method. In turn, the steady increase in the number of HLA alleles driven by the adoption of SBT as the ultimate typing method leads to the ever increasing number of cis/trans ambiguities. Over the last few years, additional sequencing with the commercially available group-specific sequencing primers (GSSPs) has replaced sequence-specific primer-polymerase chain reaction and group-specific amplification as the means of resolving cis/trans ambiguities in many laboratories. Here we summarize our 3-year experience in designing and utilizing GSSPs for resolution of HLA class I ambiguities. The panel of GSSPs used in our laboratory includes 14 primers for HLA-A, 18 for HLA-B, and 13 primers for HLA-C. The panel resolves 99.9% of all ambiguities.

The natural history of treated and untreated primary hyperparathyroidism: the parathyroid epidemiology and audit research study

BACKGROUND

Primary hyperparathyroidism (PHPT) is a common endocrine disorder with the majority of cases being mild and untreated.

AIM

To provide an update on the natural history of treated and untreated PHPT.

DESIGN

Retrospective population-based observational study.

METHODS

From 1997 to 2006, a well-defined cohort of PHPT patients was established in Tayside, Scotland. Subsequent cohorts of 'mild untreated' and 'surgically treated' PHPT patients were selected for the present study. Their serum calcium (S-Ca) and PTH concentrations were followed until September 2009. Surgical outcomes were evaluated using hospital admission data.

RESULTS

A total of 904 'mild untreated' patients were identified (median follow-up=4.7 years), with a baseline median S-Ca of 2.62 mmol/l. A general decreased trend was observed in the S-Ca concentration for up to 12 years but an increasing trend in PTH (P<0.001 in both instances). Disease progression, defined as an increase in S-Ca concentration, was observed in 121 patients (13.4%). Twenty-six (2.9%) patients had undergone surgery during the subsequent follow-up period. Baseline age and PTH concentration were the only significant risk factors for disease progression. In comparison, there were 200 'surgically treated' patients (median follow-up=5.8 years). S-Ca was normalised after surgery, in 196 patients (98%). Hospital admissions for renal complications were reduced after surgery. In conclusion, most untreated patients with mild PHPT had no progression of S-Ca but approximately 15% did show some evidence of progression. Parathyroidectomy, with a high success rate, normalized the S-Ca in patients with PHPT.

Integration of e-learning resources into a medical school curriculum

BACKGROUND

E-learning has the potential to make important contributions to medical education, but there has been limited study of a blended approach in which the digital resources are introduced alongside traditional teaching methods such as lectures.

METHODS

We describe the successful embedding of an e-learning resource into 3 of the 5 weeks of cardiovascular system teaching for 164 first-year medical students by providing scheduled slots in the timetables. A questionnaire completed by the students at the end of the 5 weeks had a response rate of 66%. Students varied in how they made use of the resource, some systematically working through it and others browsing and studying sections felt to be personally most relevant.

RESULTS

Almost all (96%) rated the e-learning resources as probably or definitely of value: they particularly valued interactive activities, animations, video demonstrations, video clips of experts and self-assessment exercises. Graduate students had a significantly more favourable assessment of the e-learning resources than their undergraduate colleagues, while female students felt the value in supporting existing learning opportunities more strongly than male students.

CONCLUSIONS

It should not be assumed that all students will choose to use an e-learning resource in the same way and instructional design should enable alternative approaches. The sequence in which the e-learning resource is used in relation to the other learning opportunities, such as lectures and PBL group discussions, may be important and merits further consideration. The experiences reported in this study provide encouragement and pointers for others engaged in the integration of e-learning in their curriculum.

Impaired dopaminergic neurotransmission and microtubule-associated protein tau alterations in human LRRK2 transgenic mice

Mutations in the Leucine Rich Repeat Kinase 2 (LRRK2) gene, first described in 2004 have now emerged as the most important genetic finding in both autosomal dominant and sporadic Parkinson's disease (PD). While a formidable research effort has ensued since the initial gene discovery, little is known of either the normal or the pathological role of LRRK2. We have created lines of mice that express human wild-type (hWT) or G2019S Lrrk2 via bacterial artificial chromosome (BAC) transgenesis. In vivo analysis of the dopaminergic system revealed abnormal dopamine neurotransmission in both hWT and G2019S transgenic mice evidenced by a decrease in extra-cellular dopamine levels, which was detected without pharmacological manipulation. Immunopathological analysis revealed changes in localization and increased phosphorylation of microtubule binding protein tau in G2019S mice. Quantitative biochemical analysis confirmed the presence of differential phospho-tau species in G2019S mice but surprisingly, upon dephosphorylation the tau isoform banding pattern in G2019S mice remained altered. This suggests that other post-translational modifications of tau occur in G2019S mice. We hypothesize that Lrrk2 may impact on tau processing which subsequently leads to increased phosphorylation. Our models will be useful for further understanding of the mechanistic actions of LRRK2 and future therapeutic screening.

Miniature Paul-Straubel ion trap with well-defined deep potential well

In some recently proposed experiments using ion traps, a Paul trap of conventional size and design is insufficient. We have constructed a miniature Paul-Straubel trap. It has a small elliptic ring ( approximately 0.2 mm) and three pairs of planar electrodes ( approximately 2 cm part) arranged so that they form a cube. The two conventional end-cap electrodes are replaced by the six planar electrodes. The ring is heatable to a high temperature for improving the uniformity of the dc potential on the ring surface. With this trap, we hope to do such fundamental studies as the true zero-point confinement of a single ion.

Effect of sperminated pullulans on drug permeation through isolated rabbit cornea and determination of ocular irritation

The aim of this study was to investigate the effect of two sperminated pullulans (SP) with a different number of amino groups (SP-L, amino group content 0.124 mmol/g polymer; and SP-H, amino group content 0.578 mmol/g polymer) on the permeation of drugs through isolated rabbit corneas. Determination of corneal hydration levels and Draize eye tests were performed to assess the safety of SP both in vitro and in vivo. For 0.2% (w/v) SP-L and 0.2% (w/v) SP-H, the enhancement ratios (ERs) with dexamethasone of 1.34 and 1.42, respectively, were not statistically significant. For ofloxacin, tobramycin and sodium fluorescein, the ERs with 0.2% SP-L were 1.37, 2.02 and 2.12, respectively, and with 0.2% SP-H the ERs were 1.84, 4.69 and 6.87, respectively; these ERs were all statistically significant. Enhancement increased with increasing amino group content of the SP. The improved transcorneal drug absorption via the paracellular route indicated opening of the tight junctions in the corneal epithelium. Irritation tests indicated that 0.2% SP-L and 0.2% SP-H did not damage the corneal tissues.

A major SNP resource for dissection of phenotypic and genetic variation in Pacific white shrimp (Litopenaeus vannamei)

Bioinformatics and re-sequencing approaches were used for the discovery of sequence polymorphisms in Litopenaeus vannamei. A total of 1221 putative single nucleotide polymorphisms (SNPs) were identified in a pool of individuals from various commercial populations. A set of 211 SNPs were selected for further molecular validation and 88% showed variation in 637 samples representing three commercial breeding lines. An association analysis was performed between these markers and several traits of economic importance for shrimp producers including resistance to three major viral diseases. A small number of SNPs showed associations with test weekly gain, grow-out survival and resistance to Taura Syndrome Virus. Very low levels of linkage disequilibrium were revealed between most SNP pairs, with only 11% of SNPs showing an r(2)-value above 0.10 with at least one other SNP. Comparison of allele frequencies showed small changes over three generations of the breeding programme in one of the commercial breeding populations. This unique SNP resource has the potential to catalyse future studies of genetic dissection of complex traits, tracing relationships in breeding programmes, and monitoring genetic diversity in commercial and wild populations of L. vannamei.

DQB1 intron 3 sequences provide an insight into the evolution of DQB1 alleles and form the basis for intron-based sequencing

The goal of this project was to obtain sequences of intron 3 of DQB1 in order to develop a sequencing-based typing protocol that provides a complete DQB1 exon 3 sequence. Current protocols do not provide complete sequences of exon 3, thus not allowing to differentiate common and well-documented alleles DQB1*0301 and *0319 and resolve some common trans-ambiguities with group-specific sequencing primer (GSSP) sequencing using positions 641 and 650. Samples homozygous for the most common DQB1 alleles were used to obtain intron 3 sequences, which were used to design intron-based primers for exon 3 amplification. The protocol was extensively validated; no allele dropouts were observed. The presented protocol allows differential typing of DQB1*0301 and *0319 and resolves some common trans-ambiguities.

Decreasing amputation rates in patients with diabetes-a population-based study

AIMS

To assess the changing rate of amputation in patients with diabetes over a 7-year period.

METHODS

All patients undergoing lower extremity amputation in Tayside, Scotland between 1 January 2000 and 31 December 2006 were identified. Temporal linkage of cases to the diabetes database was used to ascertain which amputations were in patients with diabetes.

RESULTS

The incidence of major amputations fell from 5.1 [95% confidence interval (CI) 3.8-6.4] to 2.9 (95% CI 1.9-3.8) per 1000 patients with diabetes (P < 0.05). There is a clear linear trend in the adjusted incidence of major amputation (P = 0.023 and 0.027 for age- and sex-adjusted, and duration- and sex-adjusted incidences, respectively). The adjusted incidence of total amputations followed decreased linear regression trend over the whole study period when adjusted for age and sex or diabetes duration and sex (P = 0.002).

CONCLUSIONS

There has been a significant reduction in the incidence of major lower extremity amputation in patients with diabetes over the 7-year period.

Efficient upconversion of subterahertz radiation in a high-Q whispering gallery resonator

We demonstrate efficient upconversion of subterahertz radiation into the optical domain in a high-Q whispering gallery mode resonator with quadratic optical nonlinearity. The 5x10(-3) power conversion efficiency of a cw 100 GHz signal is achieved with only 16 mW of optical pump.

Evaluation of biodegradation potential of organic compounds by river water microorganisms

The aim of this study was to assess the availability of the biodegradation potential of aniline and phenol as the indicator for evaluating pollutant impact on a river environment. Biodegradation tests employing river water microorganisms were carried out by a modified TOC-Handai method using aniline and phenol as substrates. Complete degradation time and half-life were determined as indicators expressing the biodegradation potential of aniline and phenol, respectively. Investigations in Lake Biwa-Yodo River basin for more than two years showed that the biodegradation potential of both compounds varied seasonally. In addition, aniline biodegradation potential seemed to be influenced by the hydraulic retention time at each sampling station, while downstream stations with large input of wastewater from the surrounding cities were divided from upstream stations by phenol biodegradation potential. Comparison of the biodegradation potential in rivers at different pollution levels also showed that polluted and less polluted rivers were clearly divided by phenol biodegradation potential. These results indicated that phenol biodegradation potential can be applied as an indicator for evaluating the soundness of river environment from the view point of ecological function.