bluuebunny/crossref_metadata_2025 huggingface dataset:
Taxonomic aggregation does not alleviate the lack of consistency in analysing diversity in long‐term phytoplankton monitoring data: a rejoinder to Pomati et al. (2015)
Authors: Straile Dietmar , Jochimsen Marc C. , Kümmerlin Reiner
Published: March 2015

Long‐term phytoplankton monitoring provides an important resource for studying the effects of environmental change on communities and testing ecological hypotheses. However, because of identification difficulties, maintaining consistency in the data over long periods is extremely difficult. It is usually assumed that consistency is improved when only one taxonomist is responsible throughout, and/or when data are aggregated to a coarser taxonomic level. Neither assumption has been critically tested. We address the comment of Pomati et al. (2015) on our earlier Opinion paper (Straile et al, 2013) and test these assumptions with the long‐term data from Lake Zurich.

We show that aggregation to coarser taxonomic levels does not improve data set consistency because: (i) the proportional effect of misclassification is unlikely to be reduced by lumping taxa since the fewer misclassifications affect the dynamics of an overall lower number of taxa, that is the proportional effect is constant, and (ii) because changes in detection limits will affect all taxonomic levels proportionally.

We also show that, although a single taxonomist supervised phytoplankton recordings, data consistency is undermined by: (i) learning via exchange with other taxonomists and participation in taxonomic workshops, and (ii) a reduction in detection limits of species, presumably due to an increase in the number of taxonomists (allowing an increased processing time per sample).

As a consequence of (i) a reduction in detection limits, (ii) the confirmed taxonomic learning and (iii) the failure of taxonomic aggregation to improve consistency, our new evidence strengthens the view that there are consistency problems in the Lake Zurich data set, and the need for a critical review of the conclusions of Pomati et al. (2012) and Matthews & Pomati (2012).
Habitat mediates the outcome of a cleaning symbiosis for a facultatively burrowing crayfish
Authors: Ames Catlin W. , Helms Brian S. , Stoeckel James A.
Published: March 2015

Branchiobdellidans are small, symbiotic annelids (Clitellata) that can have positive effects on the survival and growth of the crayfish host. We hypothesised that branchiobdellidans would be particularly beneficial to crayfish that move to underground burrows (characterised by poor water quality) as surface waters recede.

In surface water mesocosms, the symbioses were mutualistic, with worm (Cambarincola barbarae.) density increasing over time and crayfish (Procambarus clarkii) growing faster when worms were present.

Contrary to previous studies, the outcome did not shift from mutualism to parasitism at high worm densities.

In burrowing chambers in the laboratory, the symbiotic relationship was lost, as worm density decreased by 92% and crayfish growth ceased. Similarly, in burrows excavated in field experiments, worm density decreased by 84%.

Rather than the symbiotic relationship increasing survival when crayfish moved underground, this crayfish species may be faced with a trade‐off between the benefits of a mutualism with worms while on the surface and protection from heat stress and desiccation by burrowing when water levels are low.
Seasonal depletion of resources intensifies trophic interactions in subarctic freshwater fish communities
Authors: Hayden Brian , Harrod Chris , Sonninen Eloni , Kahilainen Kimmo K.
Published: March 2015

Climate change in recent decades has resulted in an increase in both the density and diversity of consumers in subarctic freshwater ecosystems. Despite this, harsh winter conditions in the region limit productivity and may serve as a bottleneck driving trophic interactions within the fish community, potentially determining the outcome of climate change for resident biota. However, due to the difficulties in sampling during winter months, few studies have assessed seasonal variation in the ecological interactions between native and range‐expanding species in subarctic regions.

We examined seasonal variation in activity, diet (stomach content) and resource use (δ13C and δ15N stable isotope ratios) of two fishes: the resident cold‐water‐adapted European whitefish (Coregonus lavaretus L.) and the range‐expanding cool‐water‐adapted ruffe (Gymnocephalus cernua L.) in lakes with low and high consumer density. Results were contrasted with seasonal availability of benthic and pelagic resources and indirect measures of individual fitness, that is condition, growth and estimated lipid content (muscle elemental C : N ratio) of both species.

The effects of fish density were apparent in both the diet and resource use of whitefish, which altered their diet and displayed reduced stomach fullness during winter in high‐density lakes. This was associated with an overall reduction in whitefish growth, condition and estimated lipid content in high‐density lakes, which was especially pronounced during winter.

Ruffe utilised a greater proportion of profundal resources than whitefish in both summer and winter, potentially exploiting a vacant niche. Ruffe maintained condition and lipid reserves throughout the winter, highlighting the potential for further northward range expansion of the species.

Winter acts as a seasonal bottleneck in subarctic lakes, but assumptions that this bottleneck primarily selects against warmer‐water‐adapted invasive species such as ruffe may be too restrictive. The effects of seasonal resource depletion on fish condition and invertebrate density were most severe in lakes with a high density of fish, and in these conditions, the cold‐water‐adapted resident whitefish was most adversely affected.
Norwegian elderly patients’ need for drug information and attitudes towards medication use reviews in community pharmacies
Authors: Mamen Anette Vik , Håkonsen Helle , Kjome Reidun L S , Gustavsen-Krabbesund Bjørn , Toverud Else-Lydia
Published: March 2015

Objectives

Medication use review (MUR) is a community pharmacy service in several countries. Knowledge about what patients want from such a service is limited. The aim of this study was therefore to investigate Norwegian elderly patients’ need for drug information and their attitudes towards MURs.

Methods

In Norway’s two largest cities, 162 patients (72% women; mean age: 78.9 years) who used at least one prescription drug were recruited from 18 senior centres. They were interviewed personally with a structured questionnaire (29 closed and 4 open-ended questions).

Key findings

The average number of prescription drugs used was 4.4. Seventy per cent also used over-the-counter drugs. The main source of drug information was the general practitioner (GP) followed by package inserts and pharmacy staff. For drug-related problems, 62% would contact the GP compared with 24% who preferred the pharmacist. Fifty per cent remembered no information when collecting prescriptions. However, 56% wanted to know more about their medication and 55% were interested in a MUR. The main topics they wished to address were effect/side effects and interactions. Lack of privacy was reported to be a major obstacle in the current situation.

Conclusions

This study shows that community pharmacies in Norway play a minor role regarding drug information to elderly polypharmacy patients. The GP is both their main information source and whom they contact for drug-related problems. However, half of the patients would like to know more about their medication. More than half were positive towards taking part in a MUR.
Easy and cheap way to prepare skin extenders
Authors: Stanizzi Antonio , Tartaglione Caterina , Bolletta Elisa , Gioacchini Matteo , Bottoni Manuela , Talevi Davide , Di Benedetto Giovanni
Published: March 2015

Skin extender is a very useful method to repair wounds when oedema and skin retraction make a direct suture impossible. We have developed a new, simple and cheap way to prepare skin extenders based only on elastic vessel loops and metal clips stapler commonly used for skin suture and available in any operating room.

This simple method can be performed both in the operating room and at the patient bedside, even under local anaesthesia, causes no bleeding and appears to be inexpensive and rapidly usable and should be made readily available in any hospital.
The nested graft acts by inducing the process of de‐senescence of the fibroblasts in chronic venous ulcers
Authors: Gualdi Giulio , Crotti Silvia , Monari Paola , Calzavara‐Pinton Piergiacomo , Vitali Massimiliano , Baronio Manuela , Lougaris Vassilios
Published: March 2015

Senescent fibroblasts, which are present in chronic ulcers, are the reason for the wound becoming chronic. In this study, we introduce full‐thickness micro skin grafts in the ulcer, a surgical technique known as a ‘nested graft’, which gave encouraging results leading to complete wound healing in all patients. The assessment of fibroblast cultures taken from the wound before and after treatment and comparison with fibroblasts from healthy skin showed that the fibroblasts taken from the ulcer after the nested graft treatment acquire morpho‐functional characteristics overlapping those of fibroblasts from healthy skin. This surgical approach is, therefore, able to lead to the healing of chronic ulcers through the de‐senescence of the fibroblasts.
Fracture Toughness of Porous Material of LSCF in Bulk and Film Forms
Authors: Chen Zhangwei , Wang Xin , Giuliani Finn , Atkinson Alan
Published: March 2015

Fracture toughness of La0.6Sr0.4Co0.2Fe0.8O3‐δ (LSCF) in both bulk and film forms after sintering at 900°C to 1200°C was measured using both single‐edge V‐notched beam (SEVNB) 3‐point bending and Berkovich indentation. FIB/SEM slice‐and‐view observation after indentation revealed the presence of Palmqvist radial crack systems after indentation of the bulk materials. Based on crack length measurements, the fracture toughness of bulk LSCF specimens was determined to be in the range 0.54–0.99 MPa·m1/2 (depending on sintering temperature), in good agreement with the SEVNB measurements (0.57–1.13 MPa·m1/2). The fracture toughness was approximately linearly dependent on porosity over the range studied. However, experiments on films showed that the generation of observable indentation‐induced cracks was very difficult for films sintered at temperatures below 1200°C. This was interpreted as being the result of the substrate having much higher modulus than these films. Cracks were only detectable in the films sintered at 1200°C and gave an apparent toughness of 0.17 MPa·m1/2 using the same analysis as for bulk specimens. This value is much smaller than that for bulk material with the same porosity. The residual thermal expansion mismatch stress measured using XRD was found to be responsible for such a low apparent toughness.
Impact of the branched‐chain amino acid to tyrosine ratio and branched‐chain amino acid granule therapy in patients with hepatocellular carcinoma: A propensity score analysis
Authors: Tada Toshifumi , Kumada Takashi , Toyoda Hidenori , Kiriyama Seiki , Tanikawa Makoto , Hisanaga Yasuhiro , Kanamori Akira , Kitabatake Shusuke , Yama Tsuyoki
Published: March 2015

Background and Aim

It has been reported that the branched‐chain amino acid (BCAA) to tyrosine ratio (BTR) is a useful indicator of liver function and BCAA therapy is associated with a decreased incidence of hepatocellular carcinoma (HCC). However, there has not been sufficient research on the relationship between BTR and the effects of BCAA therapy after initial treatment of HCC. We investigated the impact of BTR and BCAA therapy on survival in patients with HCC.

Methods

A total of 315 patients with HCC who were treated (n = 66) or not treated (n = 249) with BCAA were enrolled; of these, 66 were selected from each group using propensity score matching. Survival from liver‐related mortality was analyzed.

Results

In patients who did not receive BCAA therapy (n = 249), multivariate analysis for factors associated with survival indicated that low BTR (≤ 4.4) was independently associated with poor prognosis in patients with HCC (hazard ratio, 1.880; 95% confidence interval, 1.125–3.143; P = 0.016). In addition, among patients selected by propensity score matching (n = 132), multivariate analysis indicated that BCAA therapy was independently associated with good prognosis in patients with HCC (hazard ratio, 0.524; 95% confidence interval, 0.282–0.973; P = 0.041). BTR was not significantly associated with survival.

Conclusions

Intervention involving BCAA therapy improved survival in patients with HCC versus untreated controls, regardless of BTR. In addition, low BTR was associated with poor prognosis in patients who did not receive BCAA therapy.
Intraoperative Ultrasonography Combined with Indocyanine Green Video‐Angiography in Patients with Cerebral Arteriovenous Malformations
Authors: Wang Hui , Ye Zhuo‐peng , Huang Zhen‐chao , Luo Lun , Chen Chuan , Guo Ying
Published: March 2015

BACKGROUND AND PURPOSE

During the operation, accurately identifying the boundary of cerebral arteriovenous malformation (AVM) and discriminating between feeding arteries and draining veins is the key to successful surgical treatment of cerebral AVM. We evaluated the application of intraoperative ultrasonography (IOU) combined with intraoperative indocyanine green video‐angiography (IOICGA) in the patients with cerebral AVM.

METHODS

The effects of IOU combined with IOICGA on AVM surgery were observed in 12 patients with cerebral AVM.

RESULTS

The lesions of cerebral AVM were completely removed in the 12 patients. IOU could clearly visualize the boundary of AVM, so no patients had massive hemorrhage caused by rupture of malformed vessels. IOU also could detect the location of deep vessels and a total of 11 deep vessels were identified in the 12 patients. IOICGA was performed 41 times altogether in the 12 patients, and 31 feeding arteries and 10 draining veins were identified, so there was no massive hemorrhage caused by misjudgment of feeding arteries or draining veins.

CONCLUSIONS

IOU combined with IOICGA can identify the boundary of AVM, detect deep vessels, and discriminate between feeding arteries and draining veins, reducing operation difficulty, decreasing mortality and disability rate, and increasing the rate of complete excision.
Transorbital Ultrasonographic Measurement of Optic Nerve Sheath Diameter in Brain Death
Authors: Topcuoglu Mehmet A. , Arsava E. Murat , Bas D. Funda , Kozak Hasan H.
Published: March 2015

BACKGROUND

Ultrasonographic measurement of optic nerve sheath diameter (ONSD) can successfully be used to estimate intracranial pressure (ICP) elevation. Its utility in corroboration of brain death (BD) was herein studied.

METHODS

ONSD was measured in 29 subjects with BD; in 19 comatose patients (with raised ICP in 11), 20 patients with various neurological diseases, and 40 healthy control subjects. The distance between the inner and outer edges of the echolucent lines around hyperechoic area surrounding the optic nerve (ON) was identified as ONSD external (ONSDe) and ONSD internal (ONSDi).

RESULTS

Compared to patients with neurological diseases (5.75 ± .79 mm) or healthy controls (5.98 ± .63 mm), ONSDe was significantly higher in comatose patients (7.61 ± .97 and 6.71 ± 1.07 mm in those with and without raised ICP) and BD subjects (8.34 ± .66 mm). ONSDi showed similar trends across the groups: 6.09 ± .71 mm in BD; 5.89 ± .37 mm in comatose control with elevated ICP; 5.16 ± .49 mm in comatose control with normal ICP; 4.36 ± .68 mm in neurological control; 4.69 ± .67 mm in healthy control. The accuracy of ONSDe measurements in differentiating patients with ICP elevation (n = 40) was .965 as determined by area under the curve (AUC) of receiver‐operator characteristics curves. Similarly, accuracy in discrimination of BD was .952. However, ONSDe showed limited yield to identify BD cases among comatose patients with Glasgow coma scale score of 3, where accuracy was .803 (95% CI: .709‐.816) and decreased further to .722 (95% CI: .610‐.816) when analyses were restricted to comatose patients with ICP elevation. AUC values for ONSDi was similar or lower.

CONCLUSION

ONSD is significantly greater in subjects with BD. However, quantification of ONSD cannot discriminate BD subjects from comatose ones with raised ICP with 100% certainty.
‘Pure’ Farsi and political sensitivities: Language and ideologies in Farsi complementary language classrooms in Denmark
Authors: Karrebæk Martha Sif , Ghandchi Narges
Published: March 2015

This paper presents an insight into two Farsi complementary language classrooms in Copenhagen, Denmark, characterised by political sensitivities. We illustrate a number of characteristic features of the classrooms concerning language use, pedagogical methods and cultural phenomena, which were related to key adults’ preferences, and we consider possible interpretations of them as indexical signs. In particular, we emphasise ideological interpretations (e.g. the monolingualism norm and language purism) and we relate the classroom characteristics to the contemporary state of Iran as well as to the time and place in which the classes occurred. We analyse both explicit metapragmatic messages and implicit ways of indicating ideologies, and see both types as characterised by avoidance of particular referents, that is, by unmentionables.
Sex Hormones Predict the Incidence of Erectile Dysfunction: From a Population-Based Prospective Cohort Study (FAMHES)
Authors: Luo Yawen , Zhang Haiying , Liao Ming , Tang Q.i.n. , Huang Yuzhen , Xie Jinling , Tang Y.a.n. , Tan Aihua , Gao Yong , Lu Zheng , Yao Ziting , Jiang Yonghua , Lin Xinggu , Wu Chunlei , Yang Xiaobo , Mo Zengnan
Published: March 2015

Introduction

The decline of testosterone has been known to be associated with the prevalence of erectile dysfunction (ED), but the causal relationship between sex hormones and ED is still uncertain.

Aim

To prove the association between sex hormones and ED, we carried out a prospective cohort study based on our previous cross-sectional study.

Methods

We performed a prospective cohort study of 733 Chinese men who participated in Fangchenggang Area Males Health and Examination Survey from September 2009 to December 2009 and were followed for 4 years. Erectile function was estimated by scores of the five-item International Index of Erectile Dysfunction (IIEF-5) and relative ratios (RRs) were estimated using the Cox proportional hazards regression model.

Main Outcome Measures

Data were collected at follow-up visit and included sex hormone measurements, IIEF-5 scores, physical examination, and health questionnaires.

Results

Men with the highest tertile of free testosterone (FT) (RR = 0.21, 95% confidence interval [CI]: 0.09–0.46) and the lowest tertile of sex hormone-binding globulin (SHBG) (RR = 0.38, 95% CI: 0.19–0.73) had decreased risk of ED. In young men (aged 21–40), a decreased risk was observed with the increase of FT and bioavailable testosterone (BT) (adjusted RR and 95% CI: 0.78 [0.67–0.92] and 0.75 [0.62–0.95], respectively). Total testosterone (TT) (RR = 0.89, 95% CI: 0.81–0.98) was inversely associated with ED after adjusting for SHBG, while SHBG (RR = 1.04, 95% CI: 1.02–1.06) remained positively associated with ED after further adjusting for TT. Men with both low FT and high SHBG had highest ED risk (adjusted RR = 4.61, 95% CI: 1.33–16.0).

Conclusions

High FT and BT levels independently predicted a decreased risk of ED in young men. Further studies are urgently needed to clarify the molecular mechanisms of testosterone acting on ED.
The Association of Exercise with Both Erectile and Sexual Function in Black and White Men
Authors: Simon Ross M , Howard Lauren , Zapata Daniel , Frank Jennifer , Freedland Stephen J , Vidal Adriana C
Published: March 2015

Introduction

There is growing interest in using exercise to treat. Although many studies have highlighted the relationship between better erectile function and exercise, black men have been underrepresented in the literature.

Aims

This study aims to determine whether or not exercise is associated with better erectile as well as sexual function in black men and define a minimum exercise threshold for which better erectile/sexual function is seen in a cross-sectional study.

Methods

Our study population consisted of 295 healthy controls from a case-control study assessing risk factors for prostate cancer conducted at the Durham Veterans Affairs Medical Center, which contained a substantial proportion of black men (n = 93; 32%). Exercise and erectile/sexual function were both determined from self-reported questionnaires. Subjects were stratified into four exercise groups: <3 (sedentary), 3–8.9 (mildly active), 9–17.9 (moderately active), and ≥18 (highly active) metabolic equivalents (MET) hours/week. The association between exercise and erectile/sexual function was addressed utilizing multivariable linear regression analyses.

Main Outcome Measures

Erectile/sexual function was defined by the validated Expanded Prostate Cancer Index Composite sexual assessment, which was analyzed as a continuous variable (sexual function score). Clinically significant better function was defined as half a standard deviation (SD) (16.5 points).

Results

Median sexual function score was 53 (SD = 33). Higher exercise was associated with a better sexual function score (P < 0.001). Importantly, there was no interaction between black race and exercise (P-interaction = 0.772), meaning more exercise was linked with better erectile/sexual function regardless of race. Overall, exercise ≥18 MET hours/week predicted better erectile/sexual function (P < 0.001) with a clinically significant 17.3-point higher function. Exercise at lower levels was not statistically (P > 0.147) or clinically (≤8.14 points higher function) associated with erectile/sexual function.

Conclusions

In a racially diverse population, exercise ≥18 MET hours/week is highly associated with better erectile/sexual function regardless of race.
Viral genotype correlates with distinct liver gene transcription signatures in chronic hepatitis C virus infection
Authors: Robinson Mark W. , Aranday‐Cortes Elihu , Gatherer Derek , Swann Rachael , Liefhebber Jolanda M. P. , Filipe Ana Da Silva , Sigruener Alex , Barclay Stephen T. , Mills Peter R. , Patel Arvind H. , McLauchlan John
Published: March 2015

Background

Chronic hepatitis C virus (HCV) infection of the liver with either genotype 1 or genotype 3 gives rise to distinct pathologies, and the two viral genotypes respond differently to antiviral therapy.

Methods

To understand these clinical differences, we compared gene transcription profiles in liver biopsies from patients infected with either gt1 or gt3, and uninfected controls.

Results

Gt1‐infected biopsies displayed elevated levels of transcripts regulated by type I and type III interferons (IFN), including genes that predict response to IFN‐α therapy. In contrast, genes controlled by IFN‐γ were induced in gt3‐infected biopsies. Moreover, IFN‐γ levels were higher in gt3‐infected biopsies. Analysis of hepatocyte‐derived cell lines confirmed that the genes upregulated in gt3 infection were preferentially induced by IFN‐γ. The transcriptional profile of gt3 infection was unaffected by IFNL4 polymorphisms, providing a rationale for the reduced predictive power of IFNL genotyping in gt3‐infected patients.

Conclusions

The interactions between HCV genotypes 1 and 3 and hepatocytes are distinct. These unique interactions provide avenues to explore the biological mechanisms that drive viral genotype‐specific differences in disease progression and treatment response. A greater understanding of the distinct host–pathogen interactions of the different HCV genotypes is required to facilitate optimal management of HCV infection.
Tenofovir disoproxil fumarate has a substantial efficacy against multidrug‐resistant strains of hepatitis B virus
Authors: Baran Bulent , Soyer Ozlem Mutluay , Ormeci Asli Cifcibasi , Gokturk Suut , Evirgen Sami , Akyuz Filiz , Karaca Cetin , Demir Kadir , Besisik Fatih , Onel Derya , Gulluoglu Mine , Badur Selim , Kaymakoglu Sabahattin
Published: March 2015

Background & Aims

To evaluate the efficacy of tenofovir in chronic hepatitis B (CHB) patients with adefovir resistance (ADF‐R) and suboptimal response to adefovir (ADF‐S).

Methods

Nucleos(t)ide analogue (NA)‐naïve patients and patients with previous adefovir failure receiving tenofovir therapy for at least 6 months were included in the study. Biochemical and virological tests were obtained at baseline and 3‐month intervals in the first year and every 6 months thereafter. The primary outcome measure was complete virological response (CVR) (HBVDNA < 20 IU/ml). CVR rates were calculated by Kaplan–Meier analysis, and a multivariate Cox proportional hazard model was generated to find out factors independently associated with CVR.

Results

A total of 165 patients (118 men, mean age 42 ± 12, 64 HBeAg+) were included in the study. There were 105 patients in NA‐naïve, 32 patients in ADF‐S and 28 patients in ADF‐R groups. All patients in the ADF‐R group had multidrug resistance patterns. Mean duration of tenofovir treatment was 29 ± 14 months. CVR rates in NA‐naïve, ADF‐S and ADF‐R groups were 65% vs. 75% vs. 58% at 12th month, 77% vs. 87% vs. 79% at 24th month and 83% vs. 94% vs. 79% at 36th month respectively. According to multivariate Cox regression model, HBeAg positivity (HR = 0.56, 95%CI 0.36–0.86, P = 0.008), high baseline HBVDNA level (HR = 0.64, 95%CI 0.55–0.74, P < 0.001) and ADF‐R (HR = 0.47, 95%CI 0.28–0.81, P = 0.006) were independent predictors for CVR. Seven patients encountered mild renal dysfunction and were managed by dose adjustments.

Conclusion

CVR rates during the follow‐up show that tenofovir has a decreased, yet still potent in vivo efficacy against multidrug‐resistant strains of HBV.
The nuclease activities of both the Smr domain and an additional LDLK motif are required for an efficient anti‐recombination function of Helicobacter pylori MutS2
Authors: Damke Prashant P. , Dhanaraju Rajkumar , Marsin Stéphanie , Radicella Juan Pablo , Rao Desirazu N.
Published: March 2015

Helicobacter pylori, a human pathogen, is a naturally and constitutively competent bacteria, displaying a high rate of intergenomic recombination. While recombination events are essential for evolution and adaptation of H. pylori to dynamic gastric niches and new hosts, such events should be regulated tightly to maintain genomic integrity. Here, we analyze the role of the nuclease activity of MutS2, a protein that limits recombination during transformation in H. pylori. In previously studied MutS2 proteins, the C‐terminal Smr domain was mapped as the region responsible for its nuclease activity. We report here that deletion of Smr domain does not completely abolish the nuclease activity of HpMutS2. Using bioinformatics analysis and mutagenesis, we identified an additional and novel nuclease motif (LDLK) at the N‐terminus of HpMutS2 unique to Helicobacter and related ε‐proteobacterial species. A single point mutation (D30A) in the LDLK motif and the deletion of Smr domain resulted in ∼ 5–10‐fold loss of DNA cleavage ability of HpMutS2. Interestingly, the mutant forms of HpMutS2 wherein the LDLK motif was mutated or the Smr domain was deleted were unable to complement the hyper‐recombination phenotype of a mutS2− strain, suggesting that both nuclease sites are indispensable for an efficient anti‐recombinase activity of HpMutS2.
Cryptic biodiversity in the cytogenome of bird‐biting blackflies in North Africa
Authors: ADLER P. H. , CHERAIRIA M. , ARIGUE S. F. , SAMRAOUI B. , BELQAT B.
Published: March 2015

Bird‐biting blackflies in the Simulium (Eusimulium) aureum group (Diptera: Simuliidae) are widespread vectors of Leucocytozoon and Trypanosoma parasites. The polytene chromosomes of 619 larvae of the three nominal members of the S. aureum group in North Africa were evaluated cytogenetically for cryptic biodiversity. Seven chromosomal segregates were discovered among 29 populations in Algeria and Morocco. This diversity was based primarily on two chromosomal inversions, which have assumed unique roles in different lineages, including sex linkage, fixation, loss and autosomal polymorphism. Reproductive isolation was demonstrated for six of the seven segregates, doubling the number of species known in the area. Four species were linked with existing names: (a) Simulium mellah Giudicelli & Bouzidi, which is known only from North African high‐salinity habitats; (b) Simulium petricolum (Rivosecchi), which is tentatively conspecific with continental European populations; (c) Simulium rubzovianum (Sherban) and its synonym Simulium latinum (Rubtsov), which is widely distributed from North Africa across Europe into Western Asia, and (d) Simulium velutinum (Santos Abreu) and its new synonym Simulium tenerificum Crosskey, which is restricted to North Africa and the Canary Islands. Of the remaining entities, two are new species precinctive to North Africa and one, known only from Morocco, is of undetermined taxonomic status.
Stellaria devendrae sp. nov. (Caryophyllaceae) from western Himalaya, India
Authors: Pusalkar Prashant K. , Srivastava S. K.
Published: March 2015

Stellaria devendrae sp. nov. (Caryophyllaceae) is here described and illustrated from the Uttarakhand state of the Indian western Himalaya. It differs from the allied S. monosperma Buch.‐Ham. ex D. Don and S. paniculata Edgew. in having sub‐sessile, oblanceolate or obovate leaves with non amplexicaul, rounded to sub‐auricled leaf base; an inflorescence of a terminal, regularly and simply branched panicle of cymes; larger flowers (5–8 mm across); 5‐lobed floral disc; relatively larger sepals (4–7 mm long); petal lamina lobed for more than 1/2 to 4/5 of the lamina; filaments opposite sepals with prominent nectar glands at base; adjoining filaments not fused at base, and an inconspicuously reticulate‐papillate seed surface.
Interactions Among Different Devices and Electrical Stimulus on the Electroejaculation of Captive Agoutis (Dasyprocta leporina)
Authors: Castelo TS , Souza ALP , Lima GL , Peixoto GCX , Campos LB , Oliveira MF , Silva AR
Published: March 2015

Contents

The interactions among different electroejaculation devices associated with serial or continuous stimuli were investigated to improve the efficiency of the electroejaculation for semen collection in agoutis. Ten sexually matured male Dasyprocta leporina were restrained by the intramuscular administration of xylazine–ketamine association. Each individual was randomly subjected to four electroejaculation protocols, by combining two devices (one presenting longitudinal electrodes emitting square waves and other presenting ring electrodes emitting sine waves) and two electrical stimuli protocols (serial or continuous). A total of 40 attempts for electroejaculation were conducted in agoutis, being 10 per treatment. The most efficient treatment in providing ejaculates containing sperm (p < 0.05) was that using and electroejaculator connected to a probe with ring electrodes and associated with serial stimuli (4/7; 57%). In spite of semen parameters obtained by sine waves were adequate for using the samples for assisted reproduction, higher values for sperm motility and functional membrane integrity were obtained in the use of the square wave, independently of the electric stimulation protocol used (p < 0.05). In conclusion, we verified that the use of a device presenting a probe with ring electrodes and emitting sine waves, associated with a serial stimuli protocol, improves the efficiency for semen obtaining by electroejaculation in adults D. leporina.
How much related to skin wrinkles between facial and body site? Age‐related changes in skin wrinkle on the knee assessed by skin bioengineering techniques
Authors: Yoo M. A. , Seo Y. K. , Shin M. K. , Koh J. S.
Published: March 2015

Background/purpose

Skin aging has been focused the wrinkle on the face than on the body, so most studies have been studied the change in Crow's feet for ages. Only little is known about the age‐dependent changes of wrinkles on body sites. The aim of this study was to establish new grading criteria for severity of wrinkles on knees and to investigate the relationship of wrinkle severity with age‐ and site‐dependent.

Methods

The skin on the knee of 38 healthy Korean female volunteers, divided into two groups young and old, were photographed. Standard photograph for body wrinkle was established (grade 0~7), and then visual assessment, skin wrinkle, and skin elasticity were evaluated on Crow's feet and the knee. We examined for any significant differences and the correlation of skin aging parameters with age and two different sites.

Results

Skin wrinkle severity with standard photograph and wrinkle parameters (Ra, Rmax, Rz, and Rv) had a significantly positive correlation with age‐dependent on the knee (P < 0.001). Also, skin elastic parameters (R2, R5, R6, R7, and Q1) showed a significant negative correlation with age on the knee (P < 0.001). Skin wrinkle severity with standard photograph was highly correlated with all skin wrinkle parameters and skin elastic parameters (R2, R5, R7, and Q1) on the knee (P < 0.001). In addition, all the skin aging parameters on the knee were significantly correlated with Crow's feet (P < 0.01). Skin aging on the knee had the same tendency as the Crow's feet.

Conclusions

This study has shown the new grading criteria of wrinkles on the knee. Skin wrinkle and elasticity on the knee are age‐dependent related and aging on the knee is highly related to Crow's feet. Those parameters are using a quantitative method to evaluate body aging. Also, the knee is considered that it could be a suitable site to evaluate body aging.
NASA Clean Catalytic Combustor Program
Authors: Ekstedt E. E. , Lyon T. F. , Sabla P. E. , Dodds W. J. , Szaniszlo A. J.
Published: March 2015

The ability of catalytic combustors to promote stable combustion of lean fuel-air mixtures with flame temperatures less than 1800K, provides the potential for obtaining ultra-low nitrogen oxides emissions levels in combustion systems utilizing catalytic reactors. Another potential benefit of the use of catalytic reactors is improved combustion system life due to the reduced gas temperatures in the combustion zone. In standard combustion systems with droplet burning, primary zone gas temperatures can reach stoichiometric flame temperature levels locally and radiation levels from the primary zone are relatively high. In a catalytic combustor, the gas temperature is at the much lower flame temperature value associated with the average premixed fuel-air ratio. Other potential benefits of catalytic combustors include improved turbine life because of much reduced pattern factors, improved temperature profiles and improved combustion lean stability.
Catalytic Combustion of Actual Low and Medium Heating Value Gases
Authors: Bulzan Daniel L.
Published: March 2015

Lewis Research Center is currently evaluating catalytic combustion as part of the Critical Research and Advanced Technology Support Project sponsored by the D.O.E. Office of Fossil Energy, Division of Coal Utilization. Catalytic combustion has been shown to be capable of high combustion efficiency and low thermal NOx emissions when operated on fuels which contain negligible amounts of fuel-bound nitrogen (1,2). Catalytic combustion of residual fuels has also been reported in the literature (3 to 5). Premixing and prevaporizing the residual fuels was found to be a problem and a major drawback for their use as catalytic combustor fuels.
Combined Cycle Operating Experience
Authors: Borden J. H. , Tandon V. C.
Published: March 2015

The Westinghouse combined cycle station design and development efforts have been continuing to respond to widespread User interest for the last twenty-five years. These combined cycle plants have accumulated considerable operating experience. The data base is currently available to confirm consistently high reliability and availability in the mature operating period. However, in order to achieve mature operation, a reliability/availability growth period must be considered in the planning of User and manufacturer. As evidenced by the data base, the scheduled outages continue to be the major availability detractor and this is the area that offers challenging opportunities to the User and manufacturer for future improvements.
Axial Fan Performance With Blade-Base Clearance
Authors: Wright T.
Published: March 2015

A study to evaluate the influence of increasing the clearance between blade and hub on a controllable pitch axial fan (CPAF) is presented. Fan performance was measured over a range of increasing clearance for several settings of blade pitch angles. The resulting variations of pressure rise, flow rate and efficiency have been correlated as functions of established clearance parameters with good results. The study shows that large base clearances may result in reductions in efficiency and flow rate of 5 percent or greater in a typical CPAF configuration.
Combined Cycle Retrofit can Also Uprate Steam Plant Capability
Authors: Miliaras E. S. , Kelleher P. J. , Pasha A.
Published: March 2015

A simple, low cost approach to uprating existing steam plants is presented. The proposed uprating eliminates or reduces much of the boiler and turbine work required by conventional uprating methods. Waste heat from a gas turbine’s exhaust can be transferred into the steam cycle of an existing plant creating a combined-cycle unit with greater output than the combined capabilities of the two independent units and improved overall efficiency. When using or relocating an existing gas turbine the cost of the additional midrange capacity (steam plant uprate plus gas turbine) will be far less than the cost of new fossil capacity. The additional capacity is gained without creating a new emissions source.
Simplified IGCC With Hot Fuel Gas Combustion
Authors: Horner M. W.
Published: March 2015

Experimental testing and data analysis performed for simulated simplified IGCC system components have been completed. Earlier papers presented the program description and preliminary testing operations. This paper presents a review of the testing accomplishments and the results of data analysis.

An air-blown, fixed-bed coal gasifier, and downstream cyclone particle separator were found to retain or remove coal ash particles and alkali metals very effectively. The low calorific fuel gas delivered to a gas turbine combustor was found to be significantly closer to the current “clean fuel” specification than had been anticipated. These results are very encouraging for the further development of simplified IGCC systems utilizing hot gas cleanup. Observed ash deposition rates imply that turbine cleaning would be less frequent by at least an order of magnitude as compared to operation on treated ash-forming petroleum fuels.
Deposition From a Coal-Water Slurry Fueled Gas Turbine Combustor
Authors: White David J. , LeCren Richard T.
Published: March 2015

A two-stage coal-water slurry fueled high-pressure gas turbine combustion system employing a primary zone with a hot refractory wall and an internal slag removal system has been designed, built and tested. The molten ash or slag is largely removed internally by aerodynamic means using a form of jet impaction. Some small amount of the mineral matter in the coal, however, does escape the primary zone and exits the combustor. The overall combustion system is extremely flexible and can be readily configured to operate either with a lean or a rich reaction (primary) zone. In most cases a rich primary zone and a lean secondary zone is used.

Results showing the emission signatures of a number of coal-water slurry fuels operating with the combustor arranged in a rich primary zone configuration have been presented in a previous paper (1). NOx emissions were obtained that meet EPA regulations for stationary gas turbines. Deposition on a rig simulation of a turbine nozzle guide vane has been measured. The deposition appears to be a strong function of coal type and ash composition.
Software for the Performance Evaluation of Combined Cycles
Authors: Levine Philip , Dougherty Edward , Dohner Clark
Published: March 2015

This paper describes a software package developed under the auspices of the Electric Power Research Institute to monitor combined cycle power plant performance. By monitoring plant performance a usefull data base can be created. When trended and compared against a performance model this database can be used to schedule performance maintenance and repairs, and to evaluate the benefits of maintenance and/or upgrade options.

The software is named EMAP, an acronym for “Efficiency Maintenance Analysis Program”, and is available through EPRI.
Advanced Compressed Air Energy Storage Plants With Utilization of Thermal Energy Storage Systems
Authors: Nakhamkin M. , Schainker R. B.
Published: March 2015

This paper presents results of engineering development for utilization of thermal energy storage (TES) for Compressed Air Energy Storage (CAES) plant applications.

Presented results include the following:

- Turbomachinery cycle optimization for TES application

- TES systems engineering and optimization

- Comparative technical and economic analysis of various CAES plant concepts with TES versus a conventional CAES plant concept

The paper concludes that utilization of TES is feasible, practical and economically attractive.
Comparison Method for Complex Cycle Analysis
Authors: Cai R.
Published: March 2015

A new methodology is developed for the performance estimation of complex cycles such as conventional combined cycle, steam injected gas turbine cycle, AFBC coal burned exhaust heated combined cycle, alternative fuel heat recovery cycle and so on. The basic idea of this method is to compare the performance of the complex cycles with the well-known performance of the main sub-cycle (for example, the gas turbine cycle) in some way and then add simple correction factors if necessary. With such approach, the thermodynamic performance of complex cycles can be estimated and expressed very simply, directly and conveniently. The abovementioned complex cycles have been analyzed successfully by this method; the obtained results are brief and concise, and compared well with practical data and other detailed theoretical analysis results.
Advanced Recuperator for Compressed Air Energy Storage Plants
Authors: Nakhamkin Michael , Stange John R. , Marshall Richard , Pelini Robert , Schainker Robert B.
Published: March 2015

This paper presents solutions to the extensive corrosion problems affecting recuperators in Compressed Air Energy Storage (CAES) applications. Two advanced designs for a 50 MW CAES plant were engineered: (a) a two-section counterflow arrangement with a replaceable cold end section which operates with tube wall temperatures below the exhaust gas dew point temperature, (b) a three-section design with a flow arrangement which eliminates tube wall temperatures below the exhaust gas dew point temperature.

Presented in this paper are a general description, design specifics, performance and cost data for these two conceptual designs. Technical and economic analyses were performed to determine the most practical and economic design.
Digital Controls Retrofit of a 290MW Combined Cycle Power Generation Plant
Authors: Bostick Gary W. , Tinkham Russ
Published: March 2015

Public Service Company of Oklahoma (PSO) operates a combined cycle, Westinghouse PACE generating station which was commissioned in 1972. The plant consists of two Westinghouse 501B6 gas turbines, two heat recovery steam generation units with afterburners, and a single 120MW steam turbine generator. PSO made the decision to upgrade the complete plant control with a state-of-the-art triple modular redundant control system, designed to provide entire control of the generating station. The paper describes the overall retrofit project, from project conception and justification through installation, commissioning and operating results.
Artifacts related to tip asymmetry in high-resolution atomic force microscopy and scanning tunneling microscopy measurements of graphitic surfaces
Authors: Uluutku Berkin , Baykara Mehmet Z.
Published: March 2015

The effect of tip asymmetry on atomic-resolution scanning tunneling microscopy and atomic force microscopy measurements of graphitic surfaces has been investigated via numerical simulations. Employing a three-dimensional, crystalline, metallic tip apex and a two-layer thick graphene sample as a model system, basic calculations of the tip–sample interaction have revealed a significant effect of tip asymmetry on obtained results, including artificial modulation of site-specific chemical interaction forces and spatial distortion of observed features. Related artifacts are shown to be enhanced for tips with low lateral stiffness values. Our results emphasize that potentially erroneous interpretations of atomic-scale surface properties via imaging and spectroscopy measurements can be caused or enhanced by tip asymmetry.
Feasibility study of a dual detector configuration concept for simultaneous megavoltage imaging and dose verification in radiotherapy
Authors: Deshpande Shrikant , McNamara Aimee L. , Holloway Lois , Metcalfe Peter , Vial Philip
Published: March 2015

Purpose:

To test the feasibility of a dual detector concept for comprehensive verification of external beam radiotherapy. Specifically, the authors test the hypothesis that a portal imaging device coupled to a 2D dosimeter provides a system capable of simultaneous imaging and dose verification, and that the presence of each device does not significantly detract from the performance of the other.

Methods:

The dual detector configuration comprised of a standard radiotherapy electronic portal imaging device (EPID) positioned directly on top of an ionization‐chamber array (ICA) with 2 cm solid water buildup material (between EPID and ICA) and 5 cm solid backscatter material. The dose response characteristics of the ICA and the imaging performance of the EPID in the dual detector configuration were compared to the performance in their respective reference clinical configurations. The reference clinical configurations were 6 cm solid water buildup material, an ICA, and 5 cm solid water backscatter material as the reference dosimetry configuration, and an EPID with no additional buildup or solid backscatter material as the reference imaging configuration. The dose response of the ICA was evaluated by measuring the detector's response with respect to off‐axis position, field size, and transit object thickness. Clinical dosimetry performance was evaluated by measuring a range of clinical intensity‐modulated radiation therapy (IMRT) beams in transit and nontransit geometries. The imaging performance of the EPID was evaluated quantitatively by measuring the contrast‐to‐noise ratio (CNR) and spatial resolution. Images of an anthropomorphic phantom were also used for qualitative assessment.

Results:

The measured off‐axis and field size response with the ICA in both transit and nontransit geometries for both dual detector configuration and reference dosimetry configuration agreed to within 1%. Transit dose response as a function of object thickness agreed to within 0.5%. All IMRT test patterns and clinical IMRT beams had gamma pass rates of ≥98% at 2%/2 mm criteria. In terms of imaging performance, the measured CNR and spatial resolution (f50) were 263.23 ± 24.85 and 0.4025 ± 1.25 × 10−3 for dual detector configuration and 324 ± 26.65 and 0.4141 ± 1.14 × 10−3 for reference imaging configuration, respectively. The CNR and spatial resolution were quantitatively worse in the dual detector configuration due to the additional backscatter. The difference in imaging performance was not visible in qualitative assessment of phantom images.

Conclusions:

Combining a commercially available ICA dosimetry device with a conventional EPID did not significantly detract from the performance of either device. Further improvements in imaging performance may be achieved with an optimized design. This study demonstrates the feasibility of a dual detector concept for simultaneous imaging and dosimetry in radiation therapy.