bluuebunny/crossref_metadata_2025 huggingface dataset:
Microbiologic and Cytologic Assessment of Bronchoalveolar Lavage Fluid from Dogs with Lower Respiratory Tract Infection: 105 Cases (2001–2011)
Authors: Johnson L.R. , Queen E.V. , Vernau W. , Sykes J.E. , Byrne B.A.
Published: January 2013

Background

Documentation of lower respiratory tract infection has relied on microbiologic and cytologic findings in airway fluid, but there is no gold standard for making a definitive diagnosis.

Objective

To report cytologic and microbiologic findings in dogs diagnosed with lower respiratory tract infection through evaluation by bronchoscopy and bronchoalveolar lavage.

Animals

A total of 105 dogs with spontaneous respiratory disease.

Methods

Retrospective case review of all dogs identified through the electronic medical record database that had bronchoscopy with bronchoalveolar lavage performed between 2001 and 2011. Results of bronchoalveolar lavage cytology and microbiology were evaluated in 510 dogs, and 105 cases with septic, suppurative inflammation or bacterial growth from cultures were examined further.

Results

Bacteria were isolated from 89/105 aerobic cultures, 18/104 anaerobic cultures, and 30/99Mycoplasmaspp. cultures. The most common isolate wasMycoplasmaspp. followed byPasteurellasp.,Bordetellasp,Enterobacteriaceae, and anaerobes. A single bacterial species was cultured from 44/99 dogs (44%) and multiple bacterial species were isolated from 55/99 dogs (56%). Suppurative inflammation with intracellular bacteria was identified cytologically in 78 of 105 dogs (74%). In 27 dogs that lacked cytologic evidence of sepsis, mixed (n = 18) and neutrophilic (n = 9) inflammation was reported, andMycoplasmaspp. (13/27) orBordetellaspp. (7/27) were most commonly isolated. Most aerobic bacteria were susceptible to routinely used antimicrobial drugs.

Conclusions and Clinical Importance

Confirmation of lower respiratory tract infection in dogs is challenging and organisms can be isolated from dogs in which bacteria are not detected on cytologic examination.
Disturbed sleep in Parkinson's disease: anatomical and pathological correlates
Authors: Kalaitzakis M. E. , Gentleman S. M. , Pearce R. K. B.
Published: January 2013

Aims

Abnormal sleep is a common feature of Parkinson's disease (PD) and prodromal disorders of sleep are frequent (e.g. restless legs syndrome and rapid eye movement sleep behaviour disorder). However, the exact pathological basis of disturbed sleep remains as yet undefined.

Methods

To investigate this further, 32 PD cases were stratified into three groups: (1) PD with disturbed sleep, PD(S); (2) PD with dementia (PDD) and disturbed sleep, PDD(S); and (3) PD without disturbed sleep, PD(nS). The extent of α‐synuclein (αSyn) and Alzheimer disease (AD)‐type pathology [amyloid β peptide (Aβ) and tau] was assessed in 15 regions of the PD brain.

Results

The results demonstrate a significant association between disturbed sleep in PD and αSyn pathology in specific brainstem [locus coeruleus (P = 0.006) and raphe nuclei (P = 0.02)], hypothalamic [paramammillary nuclei (P = 0.04) and posterior nucleus (P = 0.02)], subcortical/limbic [amygdala (P = 0.03), thalamus (P = 0.01)] and cortical [entorhinal cortex (P = 0.01)] regions. A statistically significant increase of tau pathology was observed in the amygdala (P = 0.03), CA2 sector of the hippocampus (P = 0.01) and entorhinal cortex (P = 0.04) in PD cases with disturbed sleep.

Conclusions

Pathological changes in these structures, residing in the brain circuitry relating to sleep physiology, strongly predict the presence of sleep disturbances in PD.
Clinical experience and incidence of ventilator‐associated pneumonia using closed versus open suction‐system
Authors: Åkerman Eva , Larsson Catharina , Ersson Anders
Published: January 2013

ABSTRACT

Background

Studies have shown a decreasing ventilator‐associated pneumonia (VAP) incidence after prophylactic interventions bundles. The use of closed suction systems (CSS) has been suggested beneficial as a prophylactic measure.

Aim

To investigate the effects of a CSS on VAP incidence, suction circuit contamination and adverse events (AEs) compared to an open suction system (OSS) approach in a general mixed intensive care unit (ICU).

Methods

Adult patients on mechanical ventilation were consecutively included. Data were collected during four 1‐month periods where CSS and OSS were used on an alternating basis. Airway cultures were obtained at intubation, after 72 h and every Monday. After changing CSS and at extubation, the catheter tip was cultured. AEs and desaturation events during suction were monitored.

Analyse

Descriptive analysis and differences between the groups were analysed using comparative methods.

Results

No differences in airway colonization at admission between the groups were detected (Table 2). The CSS group had a higher Simplified Acute Physiology Score (SAPS) III and also a non‐significant increase in VAP incidence. Positive cultures were obtained in 50% of all the retrieved CSS catheters. There was no inter‐patient contamination in either group. Six AEs versus one (CSS/OSS) related to tube‐occlusion and secretion clogging was seen. Desaturations at suctioning were rare in both groups.

Conclusion

No beneficial effects were seen on VAP incidence or inter‐patient contamination compared to OSS. A high frequency of circuit contamination in the CSS group paralleled with experienced secretions clearance problems seem unfavourable and in concordance with previous studies.
Factors influencing admission and outcomes in gastroparesis
Authors: Bielefeldt K.
Published: January 2013

Background

Current data suggest that gastroparesis is associated with an increased mortality, with reported rates ranging from 4% to nearly 40%. Considering this variability, the goal of this study was to determine mortality rates and risk factors for adverse outcomes in gastroparesis.

Methods

Using the diagnosis code for gastroparesis, admission rates, duration of hospitalizations, discharge status, and inpatient mortality were determined for emergency department encounters and admissions compiled in the Nationwide Emergency Department Sample and Nationwide Inpatient Sample of the Agency for Healthcare Research and Quality. Comorbid conditions, procedural evaluations, age cohort, and gender distribution were examined as potential risk factors.

Key Results

More than 50% of the emergency encounters for gastroparesis resulted in admission with age, cardiovascular, renal, and infectious disorders, but not diabetes mellitus being associated with higher admission rates. Inpatient mortality was 1.2 ± 0.1%, was not negatively affected by diabetes mellitus as comorbidity, and increased with coexisting infections and with more aggressive therapy. Discharge status was similarly affected by comorbidities, treatment complications, and more aggressive therapy.

Conclusions & Inferences

These results demonstrate that gastroparesis does not come with a high mortality risk, with most deaths being due to comorbid conditions. Although gastrostomies and/or nutritional support were used in only a minority of admissions, the associated increase in morbidity and mortality highlights the need to carefully select the right candidates for such interventions and to discuss the common occurrence of adverse outcomes with patients.
Esophageal chemical clearance is impaired in gastro‐esophageal reflux disease – a 24‐h impedance‐pH monitoring assessment
Authors: Frazzoni M. , Manta R. , Mirante V. G. , Conigliaro R. , Frazzoni L. , Melotti G.
Published: January 2013

Background

Impedance‐pH monitoring allows assessment of retrograde and antegrade intra‐esophageal movement of fluids and gas. Reflux is followed by volume clearance and chemical clearance, elicited by secondary and swallow‐induced peristalsis, respectively. We aimed to assess whether chemical clearance is impaired in gastro‐esophageal reflux disease (GERD).

Methods

Blinded retrospective review of impedance‐pH tracings from patients with erosive reflux disease (ERD) and non‐erosive reflux disease (NERD), and from proton pump inhibitor (PPI)‐refractory patients before and after laparoscopic fundoplication. The number of refluxes followed within 30 s by swallow‐induced peristaltic waves was divided by the number of total refluxes to obtain a parameter representing chemical clearance namely the postreflux swallow‐induced peristaltic wave (PSPW) index.

Key Results

The PSPW index was significantly lower in 31 ERD (15%) and in 44 NERD (33%) off‐PPI patients than in 30 controls (75%), as well as in 18 ERD (16%) and in 48 NERD (31%) on‐PPI patients than in 26 on‐PPI functional heartburn (FH) cases (67%) (P < 0.05 for all comparisons). In 29 PPI‐refractory patients, the median PSPW index was unaltered by otherwise effective antireflux surgery (20% postoperatively, 21% preoperatively). The overall sensitivity, specificity, positive, and negative predictive values of the PSPW index in identifying GERD patients were 97%, 89%, 96%, and 93%.

Conclusions & Inferences

Impairment of chemical clearance is a primary pathophysiological mechanism specific to GERD: it is unaffected by medical/surgical therapy, is not found in FH, and is more pronounced in ERD than in NERD. Using the PSPW index could improve the diagnostic efficacy of impedance‐pH monitoring.
Associations between medication use and functional gastrointestinal disorders: a population‐based study
Authors: Choung R. S. , Locke G. R. , Schleck C. D. , Zinsmeister A. R. , Talley N. J.
Published: January 2013

Background

Functional GI syndromes are known to be very prevalent, but this may be linked to unrecognized medications use. We aimed to estimate the prevalence of PPI, antidepressant, and narcotic use in the general population, and to evaluate the association between each medication and functional GI syndromes adjusting for potential confounders.

Methods

In 2008 and 2009, newly revised versions of a validated bowel disease questionnaire were mailed to a community‐based cohort (total mailed = 8006) of Olmsted County, MN residents; 3831 returned the questionnaire (response rate = 48.0%). Medication usage, specifically PPIs, narcotics, and antidepressants in the last year, was elicited via three separate questions on the questionnaire. The association between each medication and GI symptom complexes was assessed using multiple variable logistic regression models.

Key Results

A total of 3515 of the respondents (92%) had complete data (mean age: 61 ± 15; 54% female). The overall proportion reporting PPI use was 20% (95% CI: 19, 22), narcotic use 12% (95% CI: 11, 13), and antidepressant use 15% (95% CI: 14, 16). PPI use was significantly associated with IBS status (OR = 1.4, 95% CI 1.1, 1.7) as well as with GERD (OR = 3.5, 95% CI 2.7, 4.4) and dyspepsia (OR = 2.0, 95% CI 1.5, 2.7). The association of PPI use with IBS was not explained by coexistent GERD or dyspepsia. Antidepressant use was significantly associated only with bloating (OR = 1.6, 1.1, 2.2).

Conclusions & Inferences

Some medications that may alter intestinal transit or bowel flora are commonly utilized by the general population, and PPI use appears to be linked to IBS.
Altered neuronal density and neurotransmitter expression in the ganglionated region of Ednrb null mice: implications for Hirschsprung's disease
Authors: Zaitoun I. , Erickson C. S. , Barlow A. J. , Klein T. R. , Heneghan A. F. , Pierre J. F. , Epstein M. L. , Gosain A.
Published: January 2013

Background

Hirschsprung's disease (HSCR) is a congenital condition in which enteric ganglia, formed from neural crest cells (NCC), are absent from the terminal bowel. Dysmotility and constipation are common features of HSCR that persist following surgical intervention. This persistence suggests that the portion of the colon that remains postoperatively is not able to support normal bowel function. To elucidate the defects that underlie this condition, we utilized a murine model of HSCR.

Methods

Mice with NCC‐specific deletion of Ednrb were used to measure the neuronal density and neurotransmitter expression in ganglia.

Key Results

At the site located proximal to the aganglionic region of P21 Ednrb null mice, the neuronal density is significantly decreased and the expression of neurotransmitters is altered compared with het animals. The ganglia in this colonic region are smaller and more isolated while the size of neuronal cell bodies is increased. The percentage of neurons expressing neuronal nNOS and VIP is significantly increased in Ednrb nulls. Conversely, the percentage of choline acetyltransferase (ChAT) expressing neurons is decreased, while Substance P is unchanged between the two genotypes. These changes are limited to the colon and are not detected in the ileum.

Conclusions & Inferences

We demonstrate changes in neuronal density and alterations in the balance of expression of neurotransmitters in the colon proximal to the aganglionic region in Ednrb null mice. The reduced neuronal density and complementary changes in nNOS and ChAT expression may account for the dysmotility seen in HSCR.
Brain white matter microstructure is associated with susceptibility to motion‐induced nausea
Authors: Napadow V. , Sheehan J. , Kim J. , Dassatti A. , Thurler A. H. , Surjanhata B. , Vangel M. , Makris N. , Schaechter J. D. , Kuo B.
Published: January 2013

Nausea is associated with significant morbidity, and there is a wide range in the propensity of individuals to experience nausea. The neural basis of the heterogeneity in nausea susceptibility is poorly understood. Our previous functional magnetic resonance imaging (fMRI) study in healthy adults showed that a visual motion stimulus caused activation in the right MT+/V5 area, and that increased sensation of nausea due to this stimulus was associated with increased activation in the right anterior insula. For the current study, we hypothesized that individual differences in visual motion‐induced nausea are due to microstructural differences in the inferior fronto‐occipital fasciculus (IFOF), the white matter tract connecting the right visual motion processing area (MT+/V5) and right anterior insula. To test this hypothesis, we acquired diffusion tensor imaging data from 30 healthy adults who were subsequently dichotomized into high and low nausea susceptibility groups based on the Motion Sickness Susceptibility Scale. We quantified diffusion along the IFOF for each subject based on axial diffusivity (AD); radial diffusivity (RD), mean diffusivity (MD) and fractional anisotropy (FA), and evaluated between‐group differences in these diffusion metrics. Subjects with high susceptibility to nausea rated significantly (P < 0.001) higher nausea intensity to visual motion stimuli and had significantly (P < 0.05) lower AD and MD along the right IFOF compared to subjects with low susceptibility to nausea. This result suggests that differences in white matter microstructure within tracts connecting visual motion and nausea‐processing brain areas may contribute to nausea susceptibility or may have resulted from an increased history of nausea episodes.
From ozone depletion to agriculture: understanding the role of UV radiation in sustainable crop production
Authors: Wargent Jason J. , Jordan Brian R.
Published: January 2013

Largely because of concerns regarding global climate change, there is a burgeoning interest in the application of fundamental scientific knowledge in order to better exploit environmental cues in the achievement of desirable endpoints in crop production. Ultraviolet (UV) radiation is an energetic driver of a diverse range of plant responses and, despite historical concerns regarding the damaging consequences of UV‐B radiation for global plant productivity as related to stratospheric ozone depletion, current developments representative of a range of organizational scales suggest that key plant responses to UV‐B radiation may be exploitable in the context of a sustainable contribution towards the strengthening of global crop production, including alterations in secondary metabolism, enhanced photoprotection, up‐regulation of the antioxidative response and modified resistance to pest and disease attack. Here, we discuss the prospect of this paradigm shift in photobiology, and consider the linkages between fundamental plant biology and crop‐level outcomes that can be applied to the plant UV‐B response, in addition to the consequences for related biota and many other facets of agro‐ecosystem processes.

Contents

Summary
1058

I.
Introduction
1058

II.
UV radiation can drive beneficial endpoints in crop production
1059

III.
UV influences a wide range of agro‐ecosystem interactions with plants and other biota
1067

IV.
UV interacts with many abiotic processes within a global agro‐environment
1069

V.
Conclusion: can we exploit UV photomorphogenesis in agriculture?
1070

Acknowledgements
1070

References
1071
Clinical Manifestations of Pediatric Psoriasis: Results of a Multicenter Study in the United States
Authors: Mercy Katherine , Kwasny Mary , Cordoro Kelly M. , Menter Alan , Tom Wynnis L. , Korman Neil , Belazarian Leah , Armstrong April W. , Levy Moise L. , Paller Amy S.
Published: January 2013

The clinical features of pediatric psoriasis warrant further attention. A national study was conducted to determine the prevalence of scalp and nail involvement and a history of guttate psoriasis at onset according to age, sex, and disease severity. One hundred eighty‐one children ages 5 to 17 years with plaque psoriasis were enrolled in a multicenter, cross‐sectional study. Subjects and guardians were asked about a history of scalp and nail involvement and whether the initial presentation was guttate. Peak psoriasis severity was assessed and defined historically as mild psoriasis (MP) or severe psoriasis (SP) according to the Physician's Global Assessment and body surface area measures. One hundred forty‐three (79.0%) subjects reported a history of scalp involvement, and 71 (39.2%) described a history of nail involvement. Boys were less likely than girls to report a history of scalp involvement (odds ratio [OR] = 0.40, 95% confidence interval [CI] = 0.19–0.84) but more likely to have had nail involvement (OR = 3.01, 95% CI = 1.62–5.60). Scalp and nail involvement was not related to psoriasis severity. In contrast, subjects with SP (35.9%) more often reported a history of guttate lesions than did those with MP (21.8%) (p = .02). Antecedent streptococcal infection was more common in children with guttate than those with plaque psoriasis at onset (p = .02) but did not correlate with severity. Sex‐related differences in scalp and nail involvement suggest koebnerization. Preceding streptococcal infection predicts guttate morphology but not severity, and initial guttate morphology is associated with eventual greater severity of disease. More aggressive monitoring and management should be considered for guttate psoriasis, given its later association with more severe disease.
Diagnostic accuracy of urine‐based kits for detection of Helicobacter pylori antibody in children
Authors: Okuda Masumi , Kamiya Shigeru , Booka Mina , Kikuchi Shogo , Osaki Takako , Hiwatani Tomoko , Maekawa Kohei , Fukuda Yoshihiro
Published: January 2013

Background

Rapid urine‐HpAb is reported to be a reliable test of Helicobacter pylori infection in adults, but there are no data on the application of the test in children. The aim of this study was to evaluate the accuracy of a urine‐based enzyme‐linked immunosorbent assay (urine‐HpELISA) and immunochromatography (rapid urine‐HpAb) kit for anti‐H. pylori immunoglobulin G antibody in children. We compared its sensitivity and specificity in reference to the 13C‐urea‐breath test (UBT) and H. pylori stool antigen test (HpSA).

Methods

In total, 101 Japanese children without significant upper‐abdominal symptoms were included (mean age, 7.1 years; range 2–15 years). Their sensitivity and specificity were evaluated in reference to the UBT and HpSA.

Results

Thirty‐seven children were judged H. pylori‐positive and 64 negative by the UBT and HpSA. No discrepancy in the results was observed between UBT and HpSA. Urine‐HpELISA showed 91.9% sensitivity and 96.9% specificity with an accuracy of 95.0%. Rapid urine‐HpAb showed 78.4% sensitivity and 100% specificity with an accuracy of 92.1%. Seven false negative results for rapid urine‐HpAb were from children aged younger than 10 years, and their antibody titers of urine‐HpELISA were lower than true positives.

Conclusions

For the diagnosis of H. pylori infection in Japanese children, both tests are non‐invasive, inexpensive, reliable and easy‐to‐perform methods giving satisfactory accuracy, although the sensitivity of the rapid urine‐HpAb kit was inferior to that of the urine‐HpELISA kit, especially in children aged younger than 10 years, showing relatively low titer of H. pylori antibody.
Virtual Worlds for Photogrammetric Image‐Based Simulation and Learning
Authors: Piatti Eduardo J. , Lerma José L.
Published: January 2013

Simulation is a common activity in many fields and pursuits, not only for teaching but also for learning, training, monitoring, research and entertainment, among others. This paper presents the criteria used to develop virtual scenarios for photogrammetric simulation based on both synthetic objects and synthetic images. The workflow used to generate three‐dimensional (3D) virtual worlds is presented together with the subsequent reconstruction of the metric perspective images (synthetic scenes) emulating any type of frame camera in any kind of terrestrial or aerial set‐up, the latter with an aeroplane, helicopter or unmanned aerial vehicle (UAV). A simulator can be used to create 3D virtual worlds in order to improve an understanding of mission planning, generate synthetic image sequences with suitable overlaps, as well as optimising image data acquisition before undertaking expensive photogrammetric surveys in the field.
Preventable maternal mortality in Morocco: the role of hospitals
Authors: Abouchadi Saloua , Alaoui Abdelali Belghiti , Meski Fatima Zahra , Bezad Rachid , De Brouwere Vincent
Published: January 2013

Objective

In 2009, the Ministry of Health of Morocco launched a national confidential enquiry around maternal deaths based on the newly implemented routine maternal death surveillance system (MDSS). The objective of this paper is to show the importance of substandard care among the factors associated with maternal deaths.

Methods

The Moroccan National Expert Committee (NEC) organised an audit of maternal deaths identified by the MDSS to determine the medical cause, the preventability of the deaths and the type of substandard care involved.

Results

Three hundred and three cases of maternal deaths were analysed for the year 2009. Direct causes accounted for 80.8%. 75.9% were considered avoidable by the NEC. The three main factors were insufficient follow‐up of care in 45.6% of cases, inadequate treatment in 43.9% and delay in seeking care in 41.3%. The auditors found that 54.3% of all maternal deaths could have been avoided if appropriate action had been taken at the health facilities.

Conclusion

The audit of maternal deaths in Morocco enabled a better understanding of the circumstances contributing to maternal deaths and pinpointed that more than half of maternal deaths were associated with substandard care in hospitals.
A chemical complementation approach reveals genes and interactions of flavonoids with other pathways
Authors: Pourcel Lucille , Irani Niloufer G. , Koo Abraham J. K. , Bohorquez‐Restrepo Andres , Howe Gregg A. , Grotewold Erich
Published: January 2013

In addition to the classical functions of flavonoids in the response to biotic/abiotic stress conditions, these phenolic compounds have been implicated in the modulation of various developmental processes. These findings suggest that flavonoids are more integral components of the plant signaling machinery than traditionally recognized. To understand how flux through the flavonoid pathway affects plant cellular processes, we used wild‐type and chalcone isomerase mutant (transparent testa 5, tt5) seedlings grown under anthocyanin inductive conditions, in the presence or absence of the flavonoid intermediate naringenin, the product of the chalcone isomerase enzyme. Because flavonoid biosynthetic genes are expressed under anthocyanin inductive conditions regardless of whether anthocyanins are formed or not, this system provides an excellent opportunity to specifically investigate the molecular changes associated with increased flux through the flavonoid pathway. By assessing genome‐wide mRNA accumulation changes in naringenin‐treated and untreated tt5 and wild‐type seedlings, we identified a flavonoid‐responsive gene set associated with cellular trafficking, stress responses and cellular signaling. Jasmonate biosynthetic genes were highly represented among the signaling pathways induced by increased flux through the flavonoid pathway. In contrast to studies showing a role for flavonoids in the control of auxin transport, no effect on auxin‐responsive genes was observed. Taken together, our data suggest that Arabidopsis can sense flavonoids as a signal for multiple fundamental cellular processes.
Infectivity of blood products from donors with occult hepatitis B virus infection
Authors: Allain Jean‐Pierre , Mihaljevic Ivanka , Gonzalez‐Fraile Maria Isabel , Gubbe Knut , Holm‐Harritshøj Lene , Garcia Jose Maria , Brojer Ewa , Erikstrup Christian , Saniewski Mona , Wernish Lorenz , Bianco Lydia , Ullum Henrik , Candotti Daniel , Lelie Nico , Gerlich Wolfram H. , Chudy Michael
Published: January 2013

Background

Occult hepatitis B virus (HBV) infection (OBI) is identified in 1:1000 to 1:50,000 European blood donations. This study intended to determine the infectivity of blood products from OBI donors.

Study Design and Methods

Recipients of previous donations from OBI donors were investigated through lookback (systematic retrieval of recipients) or traceback (triggered by clinical cases). Serologic and genomic studies were undertaken on consenting donors and recipients. Multiple variables potentially affecting infectivity were examined.

Results

A total of 45 of 105 (42.9%) donor‐recipients pairs carried antibodies to HBV core (anti‐HBc) as evidence of previous HBV infection. Subtracting 15% of anti‐HBc population background, the adjusted transmission rate was 28%. Anti‐HBc prevalence increased to 28 of 44 (63.8%) in unvaccinated recipients receiving anti‐HBs–negative OBI blood products. In contrast, four of 26 (15.4%) recipients of anti‐HBs–positive products were anti‐HBc positive. Transmission with anti‐HBs–negative products depended on volume of plasma transfused (85%‐100% with 200 mL of fresh frozen plasma [FFP], 51% with 50 mL in platelet concentrates [PCs], and 24% with 20 mL in red blood cells [RBCs], p < 0.0001 FFP vs. RBCs). The 50% minimum infectious dose of OBI HBV DNA was estimated at 1049 (117‐3441) copies. Donor and recipient strains sequence homology of at least 99% confirmed transfusion‐transmitted infection in 10 cases and excluded it in one case.

Conclusion

Blood products from donors with OBI carry a high risk of HBV transmission by transfusion. This risk is dependent on presence of anti‐HBs and viral dose. This may justify safety measures such as anti‐HBc and HBV nucleic acid test screening depending on epidemiology.
Development of a real‐time polymerase chain reaction assay for sensitive detection and quantitation of Babesia microti infection
Authors: Bloch Evan M. , Lee Tzong‐Hae , Krause Peter J. , Telford Sam R. , Montalvo Lani , Chafets Daniel , Usmani‐Brown Sahar , Lepore Timothy J. , Busch Michael P.
Published: January 2013

Background

Babesia microti, the most frequently implicated pathogen in transfusion‐transmitted babesiosis, is widely endemic in the Northeast and upper Midwestern United States. High seroprevalence in endemic areas limits antibody‐based donor screening. A high‐performance molecular test is needed to identify donors in the preseroconversion window phase as well as to discriminate past serologic exposure with parasite clearance from continued parasitemia.

Study Design and Methods

Frozen Babesia‐spiked whole blood was microcentrifuged, and the supernatant transferred and microcentrifuged again to concentrate the parasite. The DNA was extracted and amplified using real‐time polymerase chain reaction (PCR) using Babesia‐specific primers. The assay was employed in three series of experiments: 1) a validation and optimization spiking experiment, 2) a blinded serial dilution probit analysis to determine the limit of detection, and 3) evaluation of two blinded panels of clinical samples from possible babesiosis cases.

Results

At a decreasing inoculum of 445, 44.5, and 4.45 copies/mL, the assay had positive rates of 100, 97.5, and 81%, respectively. The blinded probit analysis demonstrated a detection rate of 95 and 50% at 12.92 and 1.52 parasites/2 mL of whole blood, respectively. Evaluation of clinical samples showed 13 of 21 samples to be positive, with a range of 85 to 4.8 million parasites/mL. There were no positives detected among 48 healthy donors

Conclusion

We have developed a highly sensitive and specific, quantitative real‐time PCR‐based assay for detection of B. microti that could have a useful role in blood screening. It can also be employed broadly to understand Babesia epidemiology, disease pathogenesis, and host immunology.
Noninvasive pH monitoring of platelet concentrates: a large field test
Authors: Gkoumassi Effimia , Klein‐Bosgoed Christa , Dijkstra‐Tiekstra Margriet J. , de Korte Dirk , de Wildt‐Eggen Janny
Published: January 2013

Background

Developing new quality control methods for platelet concentrates (PCs) can contribute to increasing transfusion safety and efficiency. The aim of this study was to investigate in a large field test the quality of expired PCs and whether 100% noninvasive pH monitoring can be used to predict PC quality.

Study Design and Methods

The pH of 13,693 PCs produced for transfusion was monitored daily using Blood Storage, Inc.'s pH sterile, automated fluoroscopic evaluation technology. Upon indication of compromised quality or expiration, PCs were returned and in vitro tests were performed.

Results

A total of 998 PCs were returned, of which 962 outdated, 26 had a positive BacT/ALERT reaction, seven had aggregates, one was without swirl, one had low pH, and one had high pH. BacT/ALERT was faster in identifying bacterial contamination than pH measurements. The pH at the end of the storage period was significantly lower than at the beginning. In vitro tests indicated that while the PC quality was acceptable upon expiration, it rapidly declined after expiration.

Conclusion

In this setting where the vast majority of PCs were of good quality and within acceptable pH limits, daily, noninvasive routine pH measurement has limited added value in identifying quality‐compromised PCs.
Combining serology and molecular typing of weak D role in improving D typing strategy in Egypt
Authors: Abdelrazik Abeer Mohamed , Elshafie Shahira Morsy , Ezzat Ahmed Ghada M. , Abdelaziz Hossam M.
Published: January 2013

Background

Rh discrepancies are a problem during routine testing because of partial and weak D phenotypes. Some blood units with weak and partial D expression may escape detection by serology. Limitations of serology can be overcome by molecular typing. The objective of study was to compare currently used serologic methods with molecular analysis to determine the potential application of molecular methods to improve D typing strategies and to estimate the frequency of weak D types among the Arab population.

Study Design and Methods

Fifty blood donor and patient samples with discrepant results of D phenotyping were subjected to routine serology to define the D phenotype including monoclonal anti‐D immunoglobulin M and indirect antiglobulin test. Commercially available panels of monoclonal anti‐D were used for identification of partial D and weak D phenotypes. Genomic DNA was evaluated using allele‐specific amplification polymerase chain reaction with sequence‐specific primers to define weak D type.

Results

Molecular typing confirmed most of the serology results; three samples that were not clear‐cut serologically were identified by molecular typing, two samples as weak D Type 4.2 (DAR), and one sample as weak D Type 4.0. Another two samples identified by serologic panel as weak D were unresolved by molecular typing. A sample with partial D Type II by serology revealed a Weak D Type 4.0 by molecular typing. Results interestingly showed the high frequency of weak D Type 4.2 (DAR) in Egypt.

Conclusion

RHD molecular typing can solve discrepancies during routine testing due to partial and weak D phenotypes for better transfusion outcome.
Estimating the Effects of Kyoto on Bilateral Trade Flows Using Matching Econometrics
Authors: Aichele Rahel , Felbermayr Gabriel
Published: January 2013

Many Kyoto countries fear a loss of competitiveness due to unilateral climate policy efforts; policymakers therefore call for carbon‐related border tax adjustments. With this paper we attempt to estimate the treatment effect of Kyoto commitment on bilateral export flows using regression‐adjusted differences‐in‐differences matching techniques. The gravity and international environmental agreement formation literatures provide guidelines for the choice of matching variables. We find that Kyoto countries' exports are reduced by 13 to 14 per cent due to Kyoto commitment. Trade effects are largest in energy‐intensive, homogeneous industries such as iron and steel, non‐ferrous metals, organic and inorganic chemicals but also in machinery and equipment.
Measurement of Schottky barrier height tuning using dielectric dipole insertion method at metal–semiconductor interfaces by photoelectron spectroscopy and electrical characterization techniques
Authors: Coss Brian E. , Sivasubramani Prasanna , Brennan Barry , Majhi Prashant , Wallace Robert M. , Kim Jiyoung
Published: January 2013

Schottky barrier height (ΦSBH) tuning from the insertion of dipole providing materials at the TaN/Si and TaN/GaAs interface are investigated using photoelectron spectroscopy and electrical techniques. In-situ processing and characterization of these contact interfaces is utilized to gain understanding of the formation of the dipole at the AlOx/SiO2 interface. Changes in both the band bending and vacuum work function by the insertion of AlOx/SiO2 at the interface are observed on both Si and GaAs substrates and are correlated with a large reduction in the ΦSBH on Si. Applications of this contact scheme for contact resistivity reduction, extremely shallow junctions, and Schottky barrier metal–oxide–semiconductor field effect devices are also discussed.
Metastable CdSe/MgSe quantum wells prepared by MBE with near IR intersubband absorption
Authors: Shen Aidong , Chen Guopeng , Zhao Kuaile , Lai Jung-Tso , Tamargo Maria C.
Published: January 2013

The authors report, for the first time, the growth of a metastable CdSe/MgSe quantum well structure by molecular beam epitaxy. The structure was grown on InP substrate with thin ZnCdSe and InGaAs buffers. To maintain the zincblende structure of MgSe (which naturally favors rocksalt structure), a ZnCdSe spacer layer was inserted between CdSe/MgSe quantum wells. The structural and optical properties of the sample were characterized by high-resolution x-ray diffraction and photoluminescence measurements. Intersubband transitions in the near infrared region were observed.
Modeling and optimization of an acoustic diode based on micro-bubble nonlinearity
Authors: Guo Xiasheng , Lin Zhou , Tu Juan , Liang Bin , Cheng Jianchun , Zhang Dong
Published: January 2013

The first acoustic diode (AD), which is composed by integrating a super lattice (SL) with a nonlinear medium (NLM), has recently been proposed to make a one-way street for the acoustic energy flux. This device prohibits the acoustic waves from one direction, but allows the transmission of the second harmonic wave (generated from the NLM) from the other direction. To improve its performance, it is crucial to transfer more acoustic energy from the stop-band of the acoustic filter (i.e., the SL) to its pass-band with the help of the NLM. In this work, a finite difference time domain model is developed to study the dynamic behaviors of the AD, in which a micro-bubble suspension takes the role of the NLM. Based on this model, the method of optimizing the nonlinearity-based AD is investigated by examining its performance with respect to several parameters, such as the periodicity number of the SL, the bubble size distribution, the bubble shell parameters, and the bubble concentration. It is also suggested that, instead of the rectification ratio, it might be more reasonable to characterize the performance of the AD with the energy attenuation coefficients (or transmission loss) for both incident directions.
Transient wave propagation in the ring stiffened laminated composite cylindrical shells using the method of reverberation ray matrix
Authors: Liu Chun-Chuan , Li Feng-Ming , Chen Zhao-Bo , Yue Hong-Hao
Published: January 2013

The method of reverberation ray matrix is extended to investigate the transient wave propagation and early short time transient responses of the ring stiffened laminated composite cylindrical shells subjected to impact loads. The ring stiffened laminated cylindrical shells are modeled as the continuous coupling systems between the vibration of the un-stiffened laminated cylindrical shell and the motion of the curved beams. The dynamic models of the laminated cylindrical shell and curved beams in the Laplace phase space are established on the basis of the first order shear deformation theory. The reverberation ray matrix can be determined by the boundary and continuous conditions of the ring stiffened laminated cylindrical shell. Using the fast Fourier transform algorithm, the dynamic responses of the ring stiffened laminated cylindrical shells can be computed. Through the numerical simulations, it can be seen that the early short time transient accelerations of the ring stiffened laminated cylindrical shells under impact loads are very large, while the early short time transient shear strains and displacements are very small. Furthermore, the influences of the ring stiffener number and impact load types on the early short time transient responses of the ring stiffened laminated cylindrical shells are also investigated.
Wave motion on the surface of the human tympanic membrane: Holographic measurement and modeling analysis
Authors: Cheng Jeffrey Tao , Hamade Mohamad , Merchant Saumil N. , Rosowski John J. , Harrington Ellery , Furlong Cosme
Published: January 2013

Sound-induced motions of the surface of the tympanic membrane (TM) were measured using stroboscopic holography in cadaveric human temporal bones at frequencies between 0.2 and 18 kHz. The results are consistent with the combination of standing-wave-like modal motions and traveling-wave-like motions on the TM surface. The holographic techniques also quantified sound-induced displacements of the umbo of the malleus, as well as volume velocity of the TM. These measurements were combined with sound-pressure measurements near the TM to compute middle-ear input impedance and power reflectance at the TM. The results are generally consistent with other published data. A phenomenological model that behaved qualitatively like the data was used to quantify the relative magnitude and spatial frequencies of the modal and traveling-wave-like displacement components on the TM surface. This model suggests the modal magnitudes are generally larger than those of the putative traveling waves, and the computed wave speeds are much slower than wave speeds predicted by estimates of middle-ear delay. While the data are inconsistent with simple modal displacements of the TM, an alternate model based on the combination of modal motions in a lossy membrane can also explain these measurements without invoking traveling waves.
Impulse-noise suppression in speech using the stationary wavelet transform
Authors: Nongpiur R. C. , Shpak D. J.
Published: January 2013

An approach for detecting and removing impulse noise from speech using the wavelet transform is proposed. The approach utilizes the multi-resolution property of the wavelet transform, which provides finer time resolution at higher frequencies than the short-time Fourier transform to effectively identify and remove impulse noise. The paper then describes how the impulse-detection performance is dependent on certain wavelet features and their relationships with the impulse noise and the underlying speech signal. Performance comparisons carried out with an existing method show that the wavelet approach yields much better features for detecting the impulses. To remove the impulses, an algorithm that uses the stationary wavelet transform has been developed. The algorithm uses a two-step approach where the wavelet coefficients corresponding to the impulses are suppressed in the first step and then substituted by suitable coefficients located within the vicinity of the impulse in the second step. Performance evaluations with an existing method show that the proposed algorithm gives superior results.
Direct numerical simulation of a recorder
Authors: Giordano N.
Published: January 2013

The aeroacoustics of a recorder are studied using a direct numerical simulation based on the Navier-Stokes equations in two dimensions. Spatial maps for the air pressure and velocity give a detailed picture of vortex shedding near the labium. Changes in the spectrum as a result of variations in the blowing speed are also investigated. The results are in good semi-quantitative agreement with general results for these phenomena from experiments.
Single-channel noise reduction using optimal rectangular filtering matrices
Authors: Long Tao , Chen Jingdong , Benesty Jacob , Zhang Zhenxi
Published: January 2013

This paper studies the problem of single-channel noise reduction in the time domain and presents a block-based approach where a vector of the desired speech signal is recovered by filtering a frame of the noisy signal with a rectangular filtering matrix. With this formulation, the noise reduction problem becomes one of estimating an optimal filtering matrix. To achieve such estimation, a method is introduced to decompose a frame of the clean speech signal into two orthogonal components: One correlated and the other uncorrelated with the current desired speech vector to be estimated. Different optimization cost functions are then formulated from which non-causal optimal filtering matrices are derived. The relationships among these optimal filtering matrices are discussed. In comparison with the classical sample-based technique that uses only forward prediction, the block-based method presented in this paper exploits both the forward and backward prediction as well as the temporal interpolation and, therefore, can improve the noise reduction performance by fully taking advantage of the speech property of self correlation. There is also a side advantage of this block-based method as compared to the sample-based technique, i.e., it is computationally more efficient and, as a result, more suitable for practical implementation.
Temporal modulation transfer function for efficient assessment of auditory temporal resolution
Authors: Shen Yi , Richards Virginia M.
Published: January 2013

Two common measures of auditory temporal resolution are the temporal modulation transfer function (TMTF) and the gap detection threshold (GDT). The current study addresses the lack of efficient psychophysical procedures for collecting TMTFs and the lack of literature on the comparisons of TMTF and GDT. Two procedures for efficient measurements of the TMTF are proposed: (1) A Bayesian procedure that adaptively chooses the stimulus modulation rate and depth to maximize the information gain from each trial and (2) a procedure that reduces the data collection to two adaptive staircase tracks. Results from experiments I and II showed that, for broadband carriers, these approaches provided similar results compared to TMTFs measured using traditional methods despite taking less than 10 min for data collection. Using these efficient procedures, TMTFs were measured from a large number of naive listeners and were compared to the gap detection thresholds collected from the same ears in experiment III. Results showed that the sensitivity parameter estimated from the TMTF measurements correlated well with the GDTs, whereas the cutoff rate is either uncorrelated or positively correlated with the gap detection threshold. These results suggest caution in interpreting a lower GDT as evidence for less sluggish temporal processing.
Extraction of pulse repetition intervals from sperm whale click trains for ocean acoustic data mining
Authors: Zaugg Serge , van der Schaar Mike , Houégnigan Ludwig , André Michel
Published: January 2013

The analysis of acoustic data from the ocean is a valuable tool to study free ranging cetaceans and anthropogenic noise. Due to the typically large volume of acquired data, there is a demand for automated analysis techniques. Many cetaceans produce acoustic pulses (echolocation clicks) with a pulse repetition interval (PRI) remaining nearly constant over several pulses. Analyzing these pulse trains is challenging because they are often interleaved. This article presents an algorithm that estimates a pulse's PRI with respect to neighboring pulses. It includes a deinterleaving step that operates via a spectral dissimilarity metric. The sperm whale (SW) produces trains with PRIs between 0.5 and 2 s. As a validation, the algorithm was used for the PRI-based identification of SW click trains with data from the NEMO-ONDE observatory that contained other pulsed sounds, mainly from ship propellers. Separation of files containing SW clicks with a medium and high signal to noise ratio from files containing other pulsed sounds gave an area under the receiver operating characteristic curve value of 0.96. This study demonstrates that PRI can be used for the automated identification of SW clicks and that deinterleaving via spectral dissimilarity contributes to algorithm performance.
Reduction of internal noise in auditory perceptual learning
Authors: Jones Pete R. , Moore David R. , Amitay Sygal , Shub Daniel E.
Published: January 2013

This paper examines what mechanisms underlie auditory perceptual learning. Fifteen normal hearing adults performed two-alternative, forced choice, pure tone frequency discrimination for four sessions. External variability was introduced by adding a zero-mean Gaussian random variable to the frequency of each tone. Measures of internal noise, encoding efficiency, bias, and inattentiveness were derived using four methods (model fit, classification boundary, psychometric function, and double-pass consistency). The four methods gave convergent estimates of internal noise, which was found to decrease from 4.52 to 2.93 Hz with practice. No group-mean changes in encoding efficiency, bias, or inattentiveness were observed. It is concluded that learned improvements in frequency discrimination primarily reflect a reduction in internal noise. Data from highly experienced listeners and neural networks performing the same task are also reported. These results also indicated that auditory learning represents internal noise reduction, potentially through the re-weighting of frequency-specific channels.