Ultratunable Quantum Frequency Conversion in Photonic Crystal Fiber.

Quantum frequency conversion of single photons between wavelength bands is a key enabler to realizing widespread quantum networks. We demonstrate the quantum frequency conversion of a heralded 1551 nm photon to any wavelength within an ultrabroad (1226-1408 nm) range in a group-velocity-symmetric photonic crystal fiber, covering over 150 independent frequency bins. The target wavelength is controlled by tuning only a single pump laser wavelength. We find internal, and total, conversion efficiencies of 12(1)% and 1.4(2)%, respectively. For the case of converting 1551 to 1300 nm we measure a heralded g^{(2)}(0)=0.25(6) for converted light from an input with g^{(2)}(0)=0.034(8). We expect that this photonic crystal fiber can be used for myriad quantum networking tasks.

Resource-efficient frequency conversion for quantum networks via sequential four-wave mixing.

We report a resource-efficient scheme in which a single pump laser was used to achieve frequency conversion by Bragg-scattering four-wave mixing in a photonic crystal fiber. We demonstrate bidirectional conversion of coherent light between Sr+2P1/2→2D3/2 emission wavelength at 1092 nm and the telecommunication C band with conversion efficiencies of 4.2% and 37% for up- and down-conversion, respectively. We discuss how the scheme may be viably scaled to meet the temporal, spectral, and polarization stability requirements of a hybrid light-matter quantum network.

Obese asthmatics are characterized by altered adipose tissue macrophage activation.

BACKGROUND: Adipose tissue-derived inflammation is linked to obesity-related comorbidities. This study aimed to quantify and immuno-phenotype adipose tissue macrophages (ATMs) from obese asthmatics and obese non-asthmatics and to examine associations between adipose tissue, systemic and airway inflammation. METHODS: Visceral (VAT) adipose tissue and subcutaneous (SAT) adipose tissue were collected from obese adults undergoing bariatric surgery and processed to obtain the stromovascular fraction. Pro-inflammatory (M1) and anti-inflammatory (M2) macrophages were quantified by flow cytometry. Cytospins of induced sputum were stained for differential cell counts. Plasma C-reactive protein (CRP) and CD163 were measured by ELISA. RESULTS: VAT contained a higher number of ATMs compared to SAT. A higher percentage of M1 ATMs was observed in VAT of obese asthmatics compared to obese non-asthmatics. The M1:M2 ratio in VAT was negatively associated with FEV1 %. Sputum macrophage count was correlated positively with M1 ATMs and negatively with M2 ATMs in VAT. In obese asthmatics, CRP was positively associated with M1:M2 ratio in VAT. There were no associations with CD163. An elevated ratio of M1:M2 ATMs was observed in VAT of obese asthmatics with increased disease severity. CONCLUSIONS AND CLINICAL RELEVANCE: Visceral inflammation with increased pro-inflammatory macrophages (M1) occurs in obese asthma and may be a determinant of systemic inflammation and asthma severity.

Cataract Symptom Scale: clarifying measurement.

AIM: Previous psychometric evaluation of the Cataract Symptom Scale (CSS) focused on classic assessments of reliability and validity. The aim was to investigate the psychometric properties of the CSS using the Rasch measurement model. METHODS: 243 patients drawn from the Flinders Eye Centre cataract surgery waiting-list self-administered the CSS. Rasch analysis was used to investigate the following properties of the CSS: measurement a single construct (unidimensionality), discrimination between strata of patient ability (person separation) and targeting of item difficulty to person ability. RESULTS: The CSS discriminated between four strata of patients. However, some items did not contribute towards measurement of a single construct, indicating a secondary dimension. This comprised three mobility items, which formed a separate valid subscale. Elimination of these items resulted in the CSS being a unidimensional measure. However, further item deletion was required, as symptoms items did not measure the same construct. The resultant nine-item measure was unidimensional. CONCLUSIONS: The CSS consists of two separate unidimensional constructs: mobility and visual disability. The reduced nine-item measure has good psychometric properties and is unidimensional. The CSS is essentially a measure of visual disability, and not cataract symptoms as it is claimed to be.

Structural analysis of a set of proteins resulting from a bacterial genomics project.

The targets of the Structural GenomiX (SGX) bacterial genomics project were proteins conserved in multiple prokaryotic organisms with no obvious sequence homolog in the Protein Data Bank of known structures. The outcome of this work was 80 structures, covering 60 unique sequences and 49 different genes. Experimental phase determination from proteins incorporating Se-Met was carried out for 45 structures with most of the remainder solved by molecular replacement using members of the experimentally phased set as search models. An automated tool was developed to deposit these structures in the Protein Data Bank, along with the associated X-ray diffraction data (including refined experimental phases) and experimentally confirmed sequences. BLAST comparisons of the SGX structures with structures that had appeared in the Protein Data Bank over the intervening 3.5 years since the SGX target list had been compiled identified homologs for 49 of the 60 unique sequences represented by the SGX structures. This result indicates that, for bacterial structures that are relatively easy to express, purify, and crystallize, the structural coverage of gene space is proceeding rapidly. More distant sequence-structure relationships between the SGX and PDB structures were investigated using PDB-BLAST and Combinatorial Extension (CE). Only one structure, SufD, has a truly unique topology compared to all folds in the PDB.

Brief examination of the career advancement ambition, organizational commitment, and professional commitment scales.

Using scale items taken from Wright and Larwood's 1997 original research on the cosmopolitan-local latent role construct, Desrochers and Dahir recently proposed the Career Advancement Ambition, Organizational Commitment, and Professional Commitment Scales. Desrochers and Dahir's new scales raise serious issues regarding scale validity and item integrity for their measures.

Psychological well-being and job satisfaction as predictors of job performance.

The happy-productive worker hypothesis has most often been examined in organizational research by correlating job satisfaction to performance. Recent research has expanded this to include measures of psychological well-being. However, to date, no field research has provided a comparative test of the relative contribution of job satisfaction and psychological well-being as predictors of employee performance. The authors report 2 field studies that, taken together, provide an opportunity to simultaneously examine the relative contribution of psychological well-being and job satisfaction to job performance. In Study 1, psychological well-being, but not job satisfaction, was predictive of job performance for 47 human services workers. These findings were replicated in Study 2 for 37 juvenile probation officers. These findings are discussed in terms of research on the happy-productive worker hypothesis.

A prospective randomized study of calcium alginate (Sorbsan) versus standard gauze packing following haemorrhoidectomy.

Post-haemorrhoidectomy pain is problematical but may be reduced by using less bulky haemostatic dressings in the anal canal. Fifty consecutive patients undergoing haemorrhoidectomy were prospectively randomized to receive either paraffin gauze/cotton gauze roll on calcium alginate (Sorbsan) roll as a post-operative pack. Post-operative pain was assessed at 6 h, on removal of rectal packing and at first bowel action. Haemorrhage was monitored at 6 h and removal of pack. There was no difference in the hospital stay between the two groups. Pain was significantly reduced at the time of removal/spontaneous discharge of rectal packing (P < 0.0001) and first post-operative bowel action (P = 0.0008) in the calcium alginate group. There was no significant difference in post-operative haemorrhage between the two groups. Calcium alginate dressings following haemorrhoidectomy effectively reduce post-operative pain compared to more bulky anal packs.

Gallstones.

Lifetime risk of gallstones in Australia is 14%-20%. The most common symptom of gallstones in either the gallbladder or bile duct is epigastric to right upper quadrant pain. Cholecystectomy is indicated for symptomatic gallbladder stones and is usually performed laparoscopically; surgery is rarely indicated for asymptomatic stones. Endoscopic retrograde cholangiopancreatography is indicated for complications of bile duct stones, such as jaundice, cholangitis or severe pancreatitis, and for postcholecystectomy symptoms of stones; bile duct stones may be removed in the same procedure via endoscopic sphincterotomy. Bile duct stones are mostly diagnosed by operative cholangiography at cholecystectomy. Open surgery is used when minimal-access techniques are dangerous, unsuitable or impossible.

Emotional exhaustion as a predictor of job performance and voluntary turnover.

Recent research suggests that a better understanding of emotional exhaustion requires the development of new theoretical perspectives. To that end, with the conservation of resources model (COR) as the theoretical framework, the present 1-year longitudinal study was undertaken. Composed of 52 social welfare workers, this research examined the relationship of emotional exhaustion to job satisfaction, voluntary turnover, and job performance. Positive affectivity (PA) and negative affectivity (NA) were used as control variables. Whereas emotional exhaustion was unrelated to job satisfaction, it was associated with both performance and subsequent turnover. In addition, the relationship between emotional exhaustion and performance and also between emotional exhaustion and turnover remained significant above and beyond the effects of PA and NA. Future research directions and implications of the findings are introduced.

Assessment of a new ultrafiltration blood processing system.

PURPOSE: To report our clinical experience with a new blood processing device which uses ultrafiltration. We assessed safety and efficacy by evaluating: 1 ) the quality and the quantity of intraoperative shed blood processed and reinfused to the patient 2) homologous blood requirements 3) clinical status of the patient post-transfusion. METHODS: With Ethics Committee approval, the ultrafiltration device was used in six consenting patients undergoing major elective spinal surgery. Blood samples for haematology and biochemistry tests were collected from patients post-induction of anaesthesia (baseline), 1 hr and 24 hr post-autotransfusion. Volumes of blood collected and processed, and all autologous and homologous transfusions were recorded. Patients were assessed post-operatively for any adverse effects. RESULTS: Five patients had donated blood preoperatively. One patient required homologous blood products in addition to autologous blood. In two patients, the filtration cartridge became blocked and required changing midprocessing. No patient sustained device-related complications. One patient had postoperative haematuria which resolved spontaneously within two hours. CONCLUSION: The ultrafiltration device was safe and effective in reducing homologous blood requirements in six patients undergoing elective spinal surgery. Further evaluation of the ultrafiltration device will be necessary, especially in view of the blockage of the filtration cartridge.

Helicobacter pylori colonization of Barrett's esophagus and its progression to cancer.

Helicobacter pylori (HP) plays a crucial role in gastric carcinogenesis. Few studies have looked at the relationship between HP and Barrett's esophagus/cancer. To further investigate this, a study comparing the prevalence of HP and increasing grades of dysplasia was undertaken. Biopsies from 19 malignant and 94 benign cases of Barrett's esophagus were analysed histologically for the presence of HP. 34% of non-dysplastic Barrett's epithelium was colonized with HP compared with only 17% of dysplastic/malignant cases (P = 0.04). No relationship was found between HP status and: (i) length of Barrett's esophagus; (ii) the presence of ulcers or strictures; and (iii) previous anti-reflux surgery. HP colonization of Barrett's esophagus is not uncommon. We found that HP has a negative correlation with increasing dysplasia which is analogous to gastric carcinogenesis. This finding should be investigated in prospective studies to elucidate its role in Barrett's adenocarcinoma.

The role of pleasantness and activation-based well-being in performance prediction.

This study examined the relationships between 2 measures of psychological well-being and work performance using the circumplex model of emotion as the theoretical framework. Although the pleasantness-based measure of well-being predicted subsequent work performance, the results failed to establish a relationship between the activation-based measure of well-being and work performance. Future directions and implications of the findings regarding the further refinement of the role of psychological well-being in performance prediction are introduced.

High-grade dysplasia in Barrett's oesophagus.

BACKGROUND: The management of high-grade dysplasia (HGD) in Barrett's oesophagus is a controversial and challenging problem. METHODS: An up-to-date review of the literature has been made using Index Medicus, the Medline database, and cross-referencing of major articles on this subject. RESULTS: Diagnosis should be confirmed by a second expert pathologist. Repeat multiple jumbo biopsies and brushings need to be taken to reduce sample error and exclude associated invasive cancer. In young fit patients the advantages of surgery outweight the disadvantage of missing an early adenocarcinoma. Continued endoscopic surveillance may be more appropriate in elderly patients. New technology has increased the number of options. Early results of laser and multipolar electrocoagulation ablation of Barrett's epithelium are encouraging. Photodynamic therapy appears to be ideally suited to HGD and early cancers. CONCLUSION: A selective approach to the management of HGD on an individual patient basis should be adopted.

Cost effectiveness of detecting Barrett's cancer.

BACKGROUND: Screening Barrett's oesophagus is controversial owing to a large variation in the reported incidence of neoplastic change and lack of evidence that screening improves tumour prognosis. AIMS: To determine the incidence of Barrett's cancer, its cost of detection, and stage of disease at time of diagnosis. PATIENTS AND METHODS: Data from our surveillance programme have been reviewed to assess the incidence of malignant change, tumour stage at diagnosis, and the cost per cancer detected. RESULTS: 166 patients had annual endoscopic surveillance. Six patients (five men) developed cancer-an incidence of one cancer per 59 male and 167 female patient-years of follow up. The screened group had a significantly earlier stage than a control group of unscreened cancers (p < 0.05). The cost of detecting one cancer was Pounds 14 868 for men and Pounds 42 084 for women. CONCLUSIONS: The cost of screening for Barrett's cancer is high but may be justified on the basis of the high incidence of detecting early stage disease.

Frequent loss of heterozygosity on chromosome 17 at 17q11.2-q12 in Barrett's adenocarcinoma.

Allelic loss on chromosome 17 in 18 Barrett's oesophageal tumours was analysed with 17 polymorphic microsatellite markers. Loss of heterozygosity (LOH) of one or more markers was seen in 72% (13 of 18) tumours on 17p and 56% (10 of 18) on 17q. The highest 17p losses were found at D17S799 (62%, five of eight) and D17S261 (55%, five of nine), while loss at the p53 locus was 31% (5 of 16). The highest loss on 17q was found at the TCF-2 (17q11.2-q12) locus with 66% (8 of 12) LOH. TCF-2 was the only marker lost in two of the tumour samples; furthermore, TCF-2 was lost in four other tumours which retained heterozygosity at the markers on either side of it, D17S261 and D17S740. Six markers were used to assess LOH at 17q11.2-q12, and five of eight of the tumour specimens which had LOH at TCF-2 had no other loss on 17q. No statistically significant correlations were found between loss on 17q or 17p and any clinicopathological parameters. We propose from these data that the 17q11.2-q12 region contains a novel predisposing gene in Barrett's adenocarcinomas and may represent the site of a tumour-suppressor gene.

Coping and job performance.

An organizational field study comprising 42 subjects examined the relationship between growth-oriented coping and subsequent job performance. Growth orientation was measured using the 7-item growth scale obtained from the Lazarus Ways of Coping Checklist. The hypothesized relationship between growth orientation and job performance was confirmed. Individuals obtaining high evaluations of managerial performance emphasized growth-oriented strategies in their behaviors. Further research directions are introduced.

The Ways of Coping instrument: reliability and temporal stability for a sample of employees.

Convergent support is demonstrated for the use of seven empirically derived scales of the Ways of Coping instrument developed by Lazarus and his colleagues. While the instrument is widely used, until now the internal consistency of the coping measures and stability of the factor structure have yet to be shown for a sample of employed adults. While type of job and type of coping incident reported are not dependent, analysis indicates that work and nonwork groups differ across several coping dimensions. Research implications and directions are addressed.

Coping strategies and diastolic blood pressure.

An organizational field study involving 95 civil service employees examined the ways these individuals coped with the stressful events of their daily living. Lazarus' cognitive-phenomenological analysis of psychological stress provided the theoretical framework. Subjects indicated on Lazarus' Ways of Coping Checklist those coping thoughts and actions used in the specific encounter described as stressful. As hypothesized, individuals experiencing higher diastolic blood pressure were more likely to cope using strategies characterized by wishful thinking, avoidance, and minimization of threat than were individuals exhibiting lower blood pressure. Implications from both an individual and organizational perspective are discussed.