bluuebunny/crossref_metadata_2025 huggingface dataset:
Horizontal and vertical distribution of sea lice larvae (Lepeophtheirus salmonis) in and around salmon farms in the Bay of Fundy, Canada
Authors: Nelson E J , Robinson S M C , Feindel N , Sterling A , Byrne A , Pee Ang K
Published: November 2017

The sea louse, Lepeophtheirus salmonis, is parasitic to salmonid species in the Northern Hemisphere and has become a widespread biological and economic problem for the salmon farming industry. A better understanding is needed of their spatial distribution and early life history to disrupt the life cycle of the sea louse. In this study, sea lice larval densities within salmon farms, between salmon farms and reference sites, and at various depths were quantified using both plankton pumps and plankton nets. Farm sites exhibited significantly higher densities than reference sites; however, these densities dropped an order of magnitude at a distance of 100 m from the cages. The majority of the larvae captured in the study were nauplii (93%), and densities ranged from 0 to 10 larvae/m3. Free‐swimming sea lice larvae were found to exhibit a diel cycle where nauplii larvae were in deeper waters (10–17 m) during the day and in surface waters (1–6 m) during the night. The results of this study suggest that the early life‐history stages of sea lice originate from and may remain close to active salmon farms, creating a self‐sustaining population.
An overview of cleaner fish use in Ireland
Authors: Bolton‐Warberg M
Published: November 2017

Sea lice infestations represent one of the most significant challenges facing the salmon farming industry, giving rise to lost production, additional costs of treatment and potential negative interactions with wild stocks. At present, cleaner fish, which actively remove lice from salmon, are an effective, biological, long‐term option which has been adopted by many countries. In Ireland, several key studies were conducted in the 1990s on the use of wild‐caught wrasse (corkwing, goldsinny and rock cook) as cleaner fish in experimental and commercial scale trials. More recently, the National University of Ireland Galway (NUIG), at their marine research facility in Carna (CRS), has undertaken applied research on ballan wrasse and lumpsucker. Currently, CRS is providing lumpsucker juveniles and research and development for the Irish salmon industry with support from BIM (Ireland's Seafood Development Agency) and Marine Harvest Ireland. There is a large amount of research currently being carried out in this area in all countries that are utilizing cleaner fish technology. The current focus in Ireland is the development of a native lumpsucker broodstock to facilitate its sustainable production. The aim of this article was to provide an overview of the research, challenges and use of cleaner fish in Ireland.
Swim bladder mycosis in pretty tetra (Hemigrammus pulcher) caused by Exophiala pisciphila and Phaeophleospora hymenocallidicola, and experimental verification of pathogenicity
Authors: Řehulka J , Kubátová A , Hubka V
Published: November 2017

Spontaneous invasive and chronic disseminated mycosis affected Hemigrammus pulcher kept in a public aquarium, and infection was manifested by inappetence, exophthalmia, erratic swimming, eroded scales, anaemia of the gills and abdominal distension. Internally, there was a grossly swollen swim bladder with a thickened wall filled with a dark mass. The body cavities contained a clear, light amber fluid and a swollen intestine which was full of a watery fluid containing small gas bubbles. Histopathology revealed a granulomatous inflammatory response with fungal hyphae in the lumen and wall of the swim bladder, hepatopancreas, spleen and kidneys with signs of nephrohydrosis. Exophiala pisciphila and Phaeophleospora hymenocallidicola were isolated from the swim bladder, abdominal cavity and gastrointestinal tract. The exogenous source of infection was probably the ample wooden decoration and plants inside the aquarium. Koch's postulates were fulfilled by re‐isolation of both fungal species from fish artificially infected under laboratory conditions. As P. hymenocallidicola is less capable of defence against phagocytosis, E. pisciphila probably played a major role. Severe clinical manifestations with 100% mortality developed in two fish species infected by E. pisciphila. A significant increase in the plasma levels of amino acids was observed as a result of the activation of proteolysis.
Identification and characterization of two variants of the Hfq‐sRNA‐chaperone in the fish pathogen Piscirickettsia salmonis
Authors: Marshall S H , Flores‐Herrera P , Henríquez F A , Gómez F A
Published: November 2017

Small RNA and chaperone proteins form synergistic duos that play pivotal roles in controlling gene expression in bacteria. This is the case for Hfq, a highly pleiotropic pretranslational modulator of general protein expression, which responds to harsh environmental conditions and influences fitness and virulence in a wide range of pathogenic Enterobacteria. Given this relevancy, we evaluated the presence and potential role of Hfq in the fish pathogen Piscirickettsia salmonis, a Gram‐negative bacterium that threatens the sustainability of Chilean salmon production. Using bioinformatics tools were identified and characterized two variants of Hfq, which share the consensus RNA‐binding domains and the active sites described functional Hfq other bacteria. Additionally, we demonstrated that hfq‐1 and hfq‐2 were transcriptionally active when growing in cell‐free media and in infected susceptible fish cell line. Expression of both genes differed under different growth conditions and under stress, suggesting that their roles might be independent and different, depending on the bacterial physiological status. In conclusion, we demonstrate the existence of two different and functional ORF coding for the hfq marker in marine bacteria and a preliminary analysis indicating that these two novel proteins might have relevant roles in the biology and pathogenic potential of P. salmonis.
Multicenter study of endoscopic preoperative biliary drainage for malignant hilar biliary obstruction: E‐POD hilar study
Authors: Nakai Yousuke , Yamamoto Ryuichi , Matsuyama Masato , Sakai Yuji , Takayama Yukiko , Ushio Jun , Ito Yukiko , Kitamura Katsuya , Ryozawa Shomei , Imamura Tsunao , Tsuchida Kouhei , Hayama Jo , Itoi Takao , Kawaguchi Yoshiaki , Yoshida Yu , Sugimori Kazuya , Shimura Kenji , Mizuide Masafumi , Iwai Tomohisa , Nishikawa Ko , Yagioka Hiroshi , Nagahama Masatsugu , Toda Nobuo , Saito Tomotaka , Yasuda Ichiro , Hirano Kenji , Togawa Osamu , Nakamura Kenji , Maetani Iruru , Sasahira Naoki , Isayama Hiroyuki
Published: November 2017

Background and Aim

Endoscopic nasobiliary drainage (ENBD) is often recommended in preoperative biliary drainage (PBD) for hilar malignant biliary obstruction (MBO), but endoscopic biliary stent (EBS) is also used in the clinical practice. We conducted this large‐scale multicenter study to compare ENBD and EBS in this setting.

Methods

A total of 374 cases undergoing PBD including 281 ENBD and 76 EBS for hilar MBO in 29 centers were retrospectively studied.

Results

Extrahepatic cholangiocarcinoma (ECC) accounted for 69.8% and Bismuth–Corlette classification was III or more in 58.8% of the study population. Endoscopic PBD was technically successful in 94.6%, and adverse event rate was 21.9%. The rate of post‐endoscopic retrograde cholangiopancreatography pancreatitis was 16.0%, and non‐endoscopic sphincterotomy was the only risk factor (odds ratio [OR] 2.51). Preoperative re‐intervention was performed in 61.5%: planned re‐interventions in 48.4% and unplanned re‐interventions in 31.0%. Percutaneous transhepatic biliary drainage was placed in 6.4% at the time of surgery. The risk factors for unplanned procedures were ECC (OR 2.64) and total bilirubin ≥ 10 mg/dL (OR 2.18). In surgically resected cases, prognostic factors were ECC (hazard ratio [HR] 0.57), predraiange magnetic resonance cholangiopancreatography (HR 1.62) and unplanned re‐interventions (HR 1.81). EBS was not associated with increased adverse events, unplanned re‐interventions, or a poor prognosis.

Conclusions

Our retrospective analysis did not demonstrate the advantage of ENBD over EBS as the initial PBD for resectable hilar MBO. Although the technical success rate of endoscopic PBD was high, its re‐intervention rate was not negligible, and unplanned re‐intervention was associated with a poor prognosis in resected hilar MBO.
Epithelial disruptions, but not immune cell invasion, induced secretory dysfunction following innate immune activation in a novel model of acute salivary gland injury
Authors: Shaalan Abeer , Carpenter Guy , Proctor Gordon
Published: November 2017

Background

Salivary gland (SG) injurious agents are all translated into loss of salivation (xerostomia). An association has been established between activation of innate immunity and SG injury and dysfunction. However, it remains unclear how the secretory epithelia respond by halting saliva production.

Methods

C57BL/6 submandibular glands (SMGs) were acutely challenged using a single dose of the innate immune stimulant: polyinosinic‐polycytidylic acid (poly (I:C)). Secretory capacity of the infected SMGs was substantiated by assessing the flow rate in response to pilocarpine stimulation. Depletion of the acute inflammatory cells was achieved by pre‐treating mice with RB6‐8C5 depletion antibody. Flow cytometry, histology and immunohistochemistry were conducted to verify the immune cell depletion. Epithelial expression of saliva‐driving molecules: muscarinic 3 receptor (M3R), aquaporin 5 water channel (AQP5), Na‐K‐CL‐Cotransporter 1 (NKCC1) and transmembrane member 16A (TMEM16A), was characterized using RT‐qPCR and immunohistochemistry. Tight junction (TJ) protein; zonula occludens (ZO‐1) and basement membrane (BM) protein; and laminin were assessed by immunohistochemistry.

Results

Innate immune challenge prompted dysfunction in the exocrine SGs. Dysregulated gene and protein expression of molecules that drive saliva secretion was substantiated. Aberrant expression of TJ and BM proteins followed innate immune activation. Hyposalivation in the current model was independent of myeloperoxidase (MPO)‐positive, acute inflammatory cells.

Conclusions

In this study, we developed a novel injury model of the SGs, featuring acute secretory dysfunction and immediate structural disruptions. Our results ruled out the injurious role of aggressively infiltrating inflammatory cells.
Effects of swaddled and traditional tub bathing methods on crying and physiological responses of newborns
Authors: Çaka Sinem Yalnızoğlu , Gözen Duygu
Published: November 2017

Purpose

The purpose of this study was to examine the effects of two bathing methods on crying duration and physiological measurements of newborns.

Design and Methods

A randomized trial design was used in this study. The sample consisted of newborns (n = 80) who were admitted to neonatal intensive care unit of a university hospital located in a large city. The groups were determined as swaddled bathing (SB) (n = 40) and traditional tub bathing (TTB) (n = 40) by using random number table. All newborns were bathed 24 hours after the birth. Environmental variables were organised identically in both experimental and control groups. Duration of bathing was determined as maximum 5 min in both groups. Body temperature, heart rate (HR), and O2 saturation values were evaluated before bath, just after the bath and at 10 min after the bath. The groups were compared in terms of all vital symptoms and duration of crying during bath. Pre‐bath and post‐bath stress levels between newborns in both groups were compared by using the Newborn Infant Pain Scale (NIPS).

Results

When the newborns were compared based on groups, it was observed that there was no statistically significant difference between SB and TTB groups in terms of the gestational week, APGAR score, postnatal age, and body weight. Body temperatures of the newborns in SB group just after the bath and 10 minutes after the bath were significantly higher than those in TTB group. HR was higher in TTB group in the post‐bath period. NIPS scores of the newborns in SB group after bath decreased at a statistically significant level, but the scores of the newborns in TTB group increased. The results of the study indicated that SB was effective in maintaining body temperature, SpO2 level, and HR of newborns within normal limits and may decrease stress experienced during the bath.

Practice implications

Swaddled bathing decreases behavioural stress symptoms such as crying, agitation, and pulling arms and legs back unintentionally and thus the infants feel relaxed. Swaddled bathing can be recommended because swaddled bathing method decreases behavioural stress symptoms in infants.
The role of exotic mammals in the diet of native carnivores from South America
Authors: Buenavista Setefilla , Palomares Francisco
Published: November 2017

A better understanding of the effects of exotic species is fundamental for ecosystem management, given that biological invasions are major agents of change affecting native biodiversity worldwide. However, exotic species can also have positive effects on native communities, for instance by providing additional food sources.

We reviewed dietary studies in the scientific literature published between 1980 and 2016 in order to examine the role of exotic mammals in the diets of 42 terrestrial species of the mammalian order Carnivora from South America. We recorded information about species' characteristics and analysed the ways in which they relate to exotic mammal consumption.

We found 62 references in which 11 carnivores from four families were reported to consume exotic mammals. Using only dietary studies in which the frequency of occurrence of each prey item was presented, we compiled 152 cases from 56 papers.

The frequency of occurrence of exotic mammals in the diet of South American carnivores reached on average 21%. The more common prey–carnivore interactions occurred with exotic lagomorphs, while exotic ungulates were less frequently consumed and were only preyed upon by pumasPuma concolor. Consumers with mainly carnivorous habits consumed exotic mammals more frequently than frugivorous or omnivorous species.

The carnivore species and the location of the study area influenced the frequency of occurrence of exotic mammals in the diets described. Certain carnivores, including the puma, culpeo foxLycalopex culpaeus, Pampas foxLycalopex gimnocercus, lesser grisonGalictis cujaand Molina's hog‐nosed skunkConepatus chinga, consumed more exotic mammals than average, and the occurrence of exotic mammals was the highest in the diets of carnivores in the southwestern regions of South America.

Exotic mammals in South America can create new food web interactions in the native carnivore community and can serve as an important food resource for some native species. This is particularly true in human‐transformed landscapes, where native prey populations have declined. Thus, it is important to consider the role of exotic mammals in the conservation of native carnivore populations.
Long‐term remission of central nervous system vasculitis after treatment of Hodgkin's lymphoma with chemotherapy plus rituximab
Authors: Freitas Eduardo , Marques Herlander , Cerqueira João
Published: November 2017

Central nervous system vasculitis is an uncommon disease resulting from inflammation and destruction of the blood vessels of the brain, spinal cord, and meninges, and it constitutes a challenging diagnosis. It is classified as primary when it is confined to the central nervous system. We present a previously healthy 40‐year‐old man admitted because of a left hemiparesis and one‐week history of mild bilateral frontal headache usually in the late afternoon that was relieved by paracetamol. Blood and cerebrospinal fluid workup was normal. Brain imaging showed a right frontoparietal lesion, and an abdominal lymphadenopathy was detected on the abdominal computed tomography. The lymph node and brain lesion histopathologies were compatible with Hodgkin's lymphoma and granulomatous vasculitis, respectively. He was treated with chemotherapy and rituximab as maintenance treatment during 18 months and entered clinical and imaging remission for 33 months.
Models of care for chronic kidney disease: A systematic review
Authors: Nicoll Ruairidh , Robertson Lynn , Gemmell Elliot , Sharma Pawana , Black Corri , Marks Angharad
Published: November 2017

Aim

Chronic kidney disease (CKD) is common and presents an increasing burden to patients and health services. However, the optimal model of care for patients with CKD is unclear. We systematically reviewed the clinical effectiveness of different models of care for the management of CKD.

Methods

A comprehensive search of eight databases was undertaken for articles published from 1992 to 2016. We included randomized controlled trials that assessed any model of care in the management of adults with pre‐dialysis CKD, reporting renal, cardiovascular, mortality and other outcomes. Data extraction and quality assessment was carried out independently by two authors.

Results

Results were summarized narratively. Nine articles (seven studies) were included. Four models of care were identified: nurse‐led, multidisciplinary specialist team, pharmacist‐led and self‐management. Nurse and pharmacist‐led care reported improved rates of prescribing of drugs relevant to CKD. Heterogeneity was high between studies and all studies were at high risk of bias. Nurse‐led care and multidisciplinary specialist care were associated with small improvements in blood pressure control.

Conclusion

Evidence of long term improvements in renal, cardiovascular or mortality endpoints was limited by short follow up. We found little published evidence about the effectiveness of different models of care to guide best practice for service design, although there was some evidence that models of care where health professionals deliver care according to a structured protocol or guideline may improve adherence to treatment targets.
Effects of music during daytime rest in the intensive care unit
Authors: Hansen Isabella P , Langhorn Leanne , Dreyer Pia
Published: November 2017

Background

Sleep is essential to the recovery of patients in the intensive care unit. Patients in the intensive care unit frequently experience poor sleep, characterized by sleep deprivation, sleep fragmentation and abnormal sleep architecture. Factors affecting sleep are multifactorial.

Aim

To investigate the effects of music on self‐reported quality of sleep during daytime rest among patients in the intensive care unit.

Study design

A randomized controlled trial.

Methods

The study was conducted between February and April 2016 in two Danish multidisciplinary intensive care units. The study sample consisted of 37 patients (19 in the control group and 18 in the intervention group) who complied with the criteria of inclusion for the study. Patients were randomly assigned to either an intervention group or a control group. The intervention group listened to music for 30 min during daytime rest while the control group rested without music. The Richards‐Campbell Sleep Questionnaire was used to measure the subjective quality of sleep.

Results

Significant differences in the mean scores of the subjective quality of sleep were found between the intervention group and the control group (p < 0·02). Significant differences were also found between groups in three items of sleep scores: sleep depth (p < 0·02), awakenings (p < 0·00) and the overall perceived quality of sleep (p < 0·01). The perceived noise level score was higher in the intervention group compared with the control group, although not statistically significant (p < 0·67).

Conclusion

Listening to music during daytime rest improves subjective sleep in patients in the intensive care unit. Furthermore, there are indications that listening to music reduces the subjective experience of noise in some patients.

Relevance to clinical practice

The result of this study implies that music can be an effective practice for nurses to improve sleep among patients in the intensive care unit.
Assessment of sedation level prior to neonatal intubation: A systematic review
Authors: de Kort Ellen H. M. , Halbmeijer Nienke M. , Reiss Irwin K. M. , Simons Sinno H. P.
Published: November 2017

Background

Adequate premedication before neonatal endotracheal intubation reduces pain, stress, and adverse physiological responses, diminishes duration and number of attempts at intubation, and prevents traumatic airway injury. Therefore, intubation should not be started until an adequate level of sedation is reached. It is not clear how this should be measured in the clinical situation.

Objectives

The aim of this study is to provide a systematic review of the usability and validity of scoring systems or other objective parameters to evaluate the level of sedation before intubation in neonates. Secondary aims were to describe parameters that are used to determine the level of sedation and criteria on which the decision to proceed with intubation is based.

Methods

Literature was searched (January 2017) in the following electronic databases: Embase, Medline, Web of Science, Cochrane Central Registrar of Controlled Trials, Pubmed Publisher, and Google Scholar.

Results

From 1653 hits, 20 studies were finally included in the systematic review. In 7 studies, intubation was started after a predefined time period; in 1 study, preoxygenation was the criterion to start with intubation; and in 12 studies, intubation was started in case of adequate sedation and/or relaxation. Only 4 studies described the use of 3 different objective scoring system, all in the neonatal intensive care unit, which are not validated.

Conclusion

No validated scoring systems to assess the level of sedation prior to intubation in newborns are available in the literature. Three objective sedation assessment tools seem promising but need further validation before they can be implemented in research and clinical settings.
DNA methylation of membrane‐bound catechol‐O‐methyltransferase in Malaysian schizophrenia patients
Authors: Nour El Huda Abd Rahim , Norsidah Ku Zaifah , Nabil Fikri Mohd Rahim , Hanisah Mohd Noor , Kartini Abdullah , Norlelawati A. Talib
Published: November 2017

Aim

This study examined catechol‐O‐methyltransferase (COMT) DNA methylation in the peripheral blood of schizophrenia patients and also in healthy controls to investigate its potential use as a peripheral biomarker of schizophrenia and its relations with the clinical variables of schizophrenia patients.

Methods

We examined the DNA methylation levels of COMT using genomic DNA from the peripheral blood of schizophrenia patients (n = 138) and healthy control participants (n = 132); all were Malaysian Malays. The extracted DNA was bisulfite converted, and the percentage methylation ratio value was calculated based on the results following a MethyLight protocol analysis.

Results

The percentage methylation ratio of COMT was lower in schizophrenia than it was in the healthy controls (P < 0.001) and was different between the body mass index (P = 0.003) and antipsychotic (P = 0.004) groups. The COMT DNA methylation rate was lower in patients receiving atypical antipsychotics (P = 0.004) and risperidone (P = 0.049) as compared to typical antipsychotics. The Excitement and Depressed subdomains of the Positive and Negative Syndrome Scale were inversely related (P < 0.001) and therefore predictors (Excitement: b = −11.396, t = −4.760, P < 0.001; Depressed: b = −7.789, t = −3.487, P = 0.001) of COMT DNA methylation.

Conclusion

Our results suggested that the methylation level was affected by the severity of the clinical symptoms of schizophrenia and might also be influenced by pharmacological treatment. The epigenetic alteration of COMT in the peripheral blood could be a potential peripheral biomarker of schizophrenia.
Near‐infrared spectroscopy might be a useful tool for predicting the risk of vascular complications after pediatric liver transplants: Two case reports
Authors: Shiba Juntaro , Satoh Masaaki , Taira Koki , Niwa Yasunori , Inoue Soichiro , Mizuta Koichi , Takeuchi Mamoru
Published: November 2017

In patients that have undergone liver transplants, a postoperative reduction in the blood flow of the liver graft represents a critical complication. We recently encountered an interesting phenomenon; that is, we found that the rSO2 level of the liver graft, as measured by NIRS, drops in patients that subsequently require an emergency liver biopsy. An 8‐month‐old female and an 8‐month‐old male underwent living donor liver transplants for biliary atresia. In both cases, a reduction in rSO2 was detected before an emergency liver biopsy was required. As a result of biopsy examinations, both patients were diagnosed with acute graft rejection. NIRS might be useful for graft management during the postoperative period in pediatric patients that undergo liver transplantation. After a liver transplant, a reduction in the rSO2 of the graft might be indicative of the onset of vascular complications.
An Empirical Analysis of the Determinants of Perceived Inequality
Authors: Bavetta Sebastiano , Li Donni Paolo , Marino Maria
Published: November 2017

Perception of inequality is important for the analysis of individuals' motivations and decisions and for policy assessment. Despite the broad range of analytic gains that it grants, our knowledge about measurement and determinants of perception of inequality is still limited, since it is intrinsically unobservable, multidimensional, and essentially contested. Using a novel econometric approach, we study how observable individual characteristics affect the joint distribution of a set of indicators of perceived inequality in specific domains. Using data from the International Social Survey Programme, we shed light on the associations among these indicators and how they are affected by covariates. The approach also gives insights on some results in the literature on inequality. The role of many subjective indicators for the perception of inequality is re‐examined and examples of policy applications are reviewed. The importance of our empirical approach to the measurement of perceived inequality is, in so doing, reinforced.
Resequencing of a mutant bearing an iron starvation recovery phenotype defines Slr1658 as a new player in the regulatory network of a model cyanobacterium
Authors: Zer Hagit , Margulis Ketty , Georg Jens , Shotland Yoram , Kostova Gergana , Sultan Laure D. , Hess Wolfgang R. , Keren Nir
Published: November 2017

Photosynthetic microorganisms encounter an erratic nutrient environment characterized by periods of iron limitation and sufficiency. Surviving in such an environment requires mechanisms for handling these transitions. Our study identified a regulatory system involved in the process of recovery from iron limitation in cyanobacteria. We set out to study the role of bacterioferritin co‐migratory proteins during transitions in iron bioavailability in the cyanobacterium Synechocystis sp. PCC 6803 using knockout strains coupled with physiological and biochemical measurements. One of the mutants displayed slow recovery from iron limitation. However, we discovered that the cause of the phenotype was not the intended knockout but rather the serendipitous selection of a mutation in an unrelated locus, slr1658. Bioinformatics analysis suggested similarities to two‐component systems and a possible regulatory role. Transcriptomic analysis of the recovery from iron limitation showed that the slr1658 mutation had an extensive effect on the expression of genes encoding regulatory proteins, proteins involved in the remodeling and degradation of the photosynthetic apparatus and proteins modulating electron transport. Most significantly, expression of the cyanobacterial homologue of the cyclic electron transport protein PGR5 was upregulated 1000‐fold in slr1658 disruption mutants. pgr5 transcripts in the Δslr1658 mutant retained these high levels under a range of stress and recovery conditions. The results suggest that slr1658 is part of a regulatory operon that, among other aspects, affects the regulation of alternative electron flow. Disruption of its function has deleterious results under oxidative stress promoting conditions.
Plant–arthropod interactions: who is the winner?
Authors: Stahl Elia , Hilfiker Olivier , Reymond Philippe
Published: November 2017

Herbivorous arthropods have interacted with plants for millions of years. During feeding they release chemical cues that allow plants to detect the attack and mount an efficient defense response. A signaling cascade triggers the expression of hundreds of genes, which encode defensive proteins and enzymes for synthesis of toxic metabolites. This direct defense is often complemented by emission of volatiles that attract beneficial parasitoids. In return, arthropods have evolved strategies to interfere with plant defenses, either by producing effectors to inhibit detection and downstream signaling steps, or by adapting to their detrimental effect. In this review, we address the current knowledge on the molecular and chemical dialog between plants and herbivores, with an emphasis on co‐evolutionary aspects.
Increased efficiency of targeted mutagenesis by CRISPR/Cas9 in plants using heat stress
Authors: LeBlanc Chantal , Zhang Fei , Mendez Josefina , Lozano Yamile , Chatpar Krishna , Irish Vivian F. , Jacob Yannick
Published: November 2017

The CRISPR/Cas9 system has greatly improved our ability to engineer targeted mutations in eukaryotic genomes. While CRISPR/Cas9 appears to work universally, the efficiency of targeted mutagenesis and the adverse generation of off‐target mutations vary greatly between different organisms. In this study, we report that Arabidopsis plants subjected to heat stress at 37°C show much higher frequencies of CRISPR‐induced mutations compared to plants grown continuously at the standard temperature (22°C). Using quantitative assays relying on green fluorescent protein (GFP) reporter genes, we found that targeted mutagenesis by CRISPR/Cas9 in Arabidopsis is increased by approximately 5‐fold in somatic tissues and up to 100‐fold in the germline upon heat treatment. This effect of temperature on the mutation rate is not limited to Arabidopsis, as we observed a similar increase in targeted mutations by CRISPR/Cas9 in Citrus plants exposed to heat stress at 37°C. In vitro assays demonstrate that Cas9 from Streptococcus pyogenes (SpCas9) is more active in creating double‐stranded DNA breaks at 37°C than at 22°C, thus indicating a potential contributing mechanism for the in vivo effect of temperature on CRISPR/Cas9. This study reveals the importance of temperature in modulating SpCas9 activity in eukaryotes, and provides a simple method to increase on‐target mutagenesis in plants using CRISPR/Cas9.
Maximum Bulge Height and Weld Line Displacement in Hydroforming of Tailor Welded Blanks
Authors: Kumar A. , Gautam V. , Kumar D. R.
Published: November 2017

Tailor welded blank (TWB) has many advantages over a traditional blank for manufacturing automobile sheet metal components, such as significant flexibility in product design, higher structural stiffness, and crash behavior. However, lower formability and weld line movement are some of the problems associated with forming of TWBs. Hydroforming is a potential technique to enhance formability. In this work, the effect of thickness ratio on maximum dome height and weld line movement in hydraulic bulging of laser welded interstitial-free (IF) steel blanks of different thickness combinations has been predicted using finite element (FE) simulations. The results are also validated with hydraulic bulging experiments on TWBs. It has been found that with increase in thickness ratio, the maximum bulge height decreased and weld line displacement toward thicker side increased. These results have been used to relocate the weld line toward the thinner side in the initial blanks and achieve a more uniform bulge profile of the dome. The peak pressure to achieve maximum safe dome height and percentage thinning has also been found out. The results showed huge improvement in uniformity of bulge profile with little reduction in dome height.
Microstructural Analysis of the Effects of Thermal Runaway on Li-Ion and Na-Ion Battery Electrodes
Authors: Robinson James B. , Finegan Donal P. , Heenan Thomas M. M. , Smith Katherine , Kendrick Emma , Brett Daniel J. L. , Shearing Paul R.
Published: November 2017

Thermal runaway is a phenomenon that occurs due to self-sustaining reactions within batteries at elevated temperatures resulting in catastrophic failure. Here, the thermal runaway process is studied for a Li-ion and Na-ion pouch cells of similar energy density (10.5 Wh, 12 Wh, respectively) using accelerating rate calorimetry (ARC). Both cells were constructed with a z-fold configuration, with a standard shutdown separator in the Li-ion and a low-cost polypropylene (PP) separator in the Na-ion. Even with the shutdown separator, it is shown that the self-heating rate and rate of thermal runaway in Na-ion cells is significantly slower than that observed in Li-ion systems. The thermal runaway event initiates at a higher temperature in Na-ion cells. The effect of thermal runaway on the architecture of the cells is examined using X-ray microcomputed tomography, and scanning electron microscopy (SEM) is used to examine the failed electrodes of both cells. Finally, from examination of the respective electrodes, likely due to the carbonate solvent containing electrolyte, it is suggested that thermal runaway in Na-ion batteries (NIBs) occurs via a similar mechanism to that reported for Li-ion cells.
A New Family of Symmetrical 2T2R Parallel Mechanisms Without Parasitic Motion
Authors: Ye Wei , He Leiying , Li Qinchuan
Published: November 2017

This paper focuses on parallel mechanisms (PMs) that can perform two translations and two rotations (2T2R). Two sufficient conditions for eliminating parasitic motion in 2T2R PMs are presented. A motion expression satisfying those two conditions is identified and several kinematic bonds containing that motion are found. To achieve symmetrical structures, a configurable platform that generates an instantaneous translation motion is presented, to which four limbs having identical structures are connected, leading to the construction of novel 2T2R PMs. Several designs that may have good practical values are identified and form a mechanism family. A typical mechanism is selected with its position model, workspace, singularity thoroughly investigated. Redundant limbs are added to eliminate the singularities, which then ensure the rotational capability. The proposed mechanisms have the advantages of identical limbs, no parasitic motion, and relatively high rotational capability, which can be used in several applications such as in five-axis machine.
Synthesis of a Flapping Wing Mechanism Using a Constrained Spatial RRR Serial Chain
Authors: Wang Peter L. , Taha Haithem E. , Michael McCarthy J.
Published: November 2017

This paper designs a one degree-of-freedom (1DOF) spatial flapping wing mechanism for a hovering micro-air vehicle by constraining a spatial RRR serial chain using two SS dyads. The desired wing movement defines the dimensions and joint trajectories of the RRR spatial chain. Seven configurations of the chain are selected to define seven precision points that are used to compute SS chains that control the swing and pitch joint angles. The result is a spatial RRR-2SS flapping wing mechanism that transforms the actuator rotation into control of wing swing and pitch necessary for hovering flight of a micro-air vehicle.
Tip-to-tip variation mitigation in extreme ultraviolet lithography for 7 nm and beyond metallization layers and design rule analysis
Authors: Chen Yulu , Sun Lei , Qi Zhengqing John , Zhao Shuo , Goodwin Francis , Matthew Itty , Plachecki Vince
Published: November 2017

The authors develop and present computational lithography solutions to mitigate the tip-to-tip variations in 7 nm and beyond metallization layers. An array of patterns that represent lithography challenges are generated from basic design rules. The lithography process is optimized by source mask co-optimization to achieve high image qualities and maximum overlapping process windows for all patterns. By analyzing the role of diffraction orders in forming images with tight tip-to-tip, the authors identify the diffraction orders that should be admitted or rejected in the projection imaging system. This leads to analytically derived source profiles that match and explain numerical results. The authors have also found optimal minimum pitches that can achieve robust lithography process as well as design flexibility without losing throughput. Our work provides design for manufacturability guidance to metallization layers in advanced technology nodes so that patterning failures can be avoided before time-consuming optical rule check and expensive wafer validation.
Cylindrical heat conduction and structural acoustic models for enclosed fiber array thermophones
Authors: Dzikowicz Benjamin R. , Tressler James F. , Baldwin Jeffrey W.
Published: November 2017

Calculation of the heat loss for thermophone heating elements is a function of their geometry and the thermodynamics of their surroundings. Steady-state behavior is difficult to establish or evaluate as heat is only flowing in one direction in the device. However, for a heating element made from an array of carbon fibers in a planar enclosure, several assumptions can be made, leading to simple solutions of the heat equation. These solutions can be used to more carefully determine the efficiency of thermophones of this geometry. Acoustic response is predicted with the application of a Helmholtz resonator and thin plate structural acoustics models. A laboratory thermophone utilizing a sparse horizontal array of fine (6.7 μm diameter) carbon fibers is designed and tested. Experimental results are compared with the model. The model is also used to examine the optimal array density for maximal efficiency.
ACOUSTICAL STANDARDS NEWS
Authors: Stremmel Neil B. , Struck Christopher J.
Published: November 2017

American National Standards (ANSI Standards) developed by Accredited Standards Committees S1, S2, S3, S3/SC 1, and S12 in the areas of acoustics, mechanical vibration and shock, bioacoustics, animal bioacoustics, and noise, respectively, are published by the Acoustical Society of America (ASA). In addition to these standards, ASA publishes a catalog of Acoustical American National Standards. To receive a copy of the latest Standards catalog, please contact Neil Stremmel.

Comments are welcomed on all material in Acoustical Standards News.

This Acoustical Standards News section in JASA and other information on the Standards Program of the Acoustical Society of America are available via the ASA home page: http://acousticalsociety.org.
Why orchestral musicians are bound to wear earplugs: About the ineffectiveness of physical measures to reduce sound exposure
Authors: Wenmaekers Remy , Nicolai Bareld , Hornikx Maarten , Kohlrausch Armin
Published: November 2017

Symphony orchestra musicians are exposed to noise levels that put them at risk of developing hearing damage. This study evaluates the potential effectivity of common control measures used in orchestras on open stages with a typical symphonic setup. A validated acoustic prediction model is used that calculates binaural sound exposure levels at the ears of all musicians in the orchestra. The model calculates the equivalent sound levels for a performance of the first 2 min of the 4th movement of Mahler's 1st symphony, which can be considered representative for loud orchestral music. Calculated results indicate that risers, available space, and screens at typical positions do not significantly influence sound exposure. A hypothetical scenario with surround screens shows that, even when shielding all direct sound from others, sound exposure is reduced moderately with the largest effect on players in loud sections. In contrast, a dramatic change in room acoustic conditions only leads to considerable reductions for soft players. It can be concluded that significant reductions are only reached with extreme measures that are unrealistic. It seems impossible for the studied physical measures to be effective enough to replace hearing protection devices such as ear plugs.
Natural selection shaped the rise and fall of passenger pigeon genomic diversity
Authors: Murray Gemma G. R. , Soares André E. R. , Novak Ben J. , Schaefer Nathan K. , Cahill James A. , Baker Allan J. , Demboski John R. , Doll Andrew , Da Fonseca Rute R. , Fulton Tara L. , Gilbert M. Thomas P. , Heintzman Peter D. , Letts Brandon , McIntosh George , O’Connell Brendan L. , Peck Mark , Pipes Marie-Lorraine , Rice Edward S. , Santos Kathryn M. , Sohrweide A. Gregory , Vohr Samuel H. , Corbett-Detig Russell B. , Green Richard E. , Shapiro Beth
Published: November 2017

Genetics of the passenger pigeon

The now-extinct passenger pigeon used to be one of the most numerous vertebrates on Earth. Murray
et al.
examined the genomes of four passenger pigeon samples from different locales within its range. They describe the interplay between passenger pigeon population size, genome structure and recombination, and natural selection. They conclude that a reduction in genetic diversity provided few avenues for the bird to respond to human pressures, which ultimately drove it to extinction.

Science
, this issue p.
951
Comment on “The extent of forest in dryland biomes”
Authors: Griffith Daniel M. , Lehmann Caroline E. R. , Strömberg Caroline A. E. , Parr Catherine L. , Pennington R. Toby , Sankaran Mahesh , Ratnam Jayashree , Still Christopher J. , Powell Rebecca L. , Hanan Niall P. , Nippert Jesse B. , Osborne Colin P. , Good Stephen P. , Anderson T. Michael , Holdo Ricardo M. , Veldman Joseph W. , Durigan Giselda , Tomlinson Kyle W. , Hoffmann William A. , Archibald Sally , Bond William J.
Published: November 2017

Bastin
et al
. (Reports, 12 May 2017, p. 635) infer forest as more globally extensive than previously estimated using tree cover data. However, their forest definition does not reflect ecosystem function or biotic composition. These structural and climatic definitions inflate forest estimates across the tropics and undermine conservation goals, leading to inappropriate management policies and practices in tropical grassy ecosystems.
Structural basis of bacterial transcription activation
Authors: Liu Bin , Hong Chuan , Huang Rick K. , Yu Zhiheng , Steitz Thomas A.
Published: November 2017

Structural basis for transcription activation

Bacteria can initiate transcription through two independent classes of recruitment mechanisms. Liu
et al.
determined the cryo-electron microscopy structure of an intact class I transcription activation complex. The positions and orientations of all the components and the detailed protein-protein and protein-nucleic acid interactions reveal how an activator interacts with the promoter DNA and recruits RNA polymerase through the class I mechanism. Together with a recently reported class II transcription activation complex, the findings complete our structural understanding of bacterial transcription activation.

Science
, this issue p.
947
Racing for academic glory and patents: Lessons from CRISPR
Authors: Rai Arti K. , Cook-Deegan Robert
Published: November 2017

Overly broad patents must be reined in
Evolution of flower color pattern through selection on regulatory small RNAs
Authors: Bradley Desmond , Xu Ping , Mohorianu Irina-Ioana , Whibley Annabel , Field David , Tavares Hugo , Couchman Matthew , Copsey Lucy , Carpenter Rosemary , Li Miaomiao , Li Qun , Xue Yongbiao , Dalmay Tamas , Coen Enrico
Published: November 2017

How the snapdragon chooses its color

In some snapdragons, a yellow spot in a field of magenta shows the bee the best place to go. Flowers of a related subspecies are mainly yellow with magenta veins marking the target. Bradley
et al.
analyzed a locus that regulates the pattern of color. The locus contains an inverted gene duplication that encodes small RNAs that repress pigment biosynthesis. Analysis of flowers derived from a region of the Pyrenees where the subspecies coexist indicates that natural selection is operating upon the locus.

Science
, this issue p.
925
Beyond plastic waste
Authors: MacArthur Ellen
Published: November 2017

With more than 8 million tons of plastic entering the ocean each year, humanity
must urgently rethink the way we make and use plastics, so that they do not
become waste in the first place.
Tackler’s head position relative to the ball carrier is highly correlated with head and neck injuries in rugby
Authors: Sobue Shogo , Kawasaki Takayuki , Hasegawa Yoshinori , Shiota Yuki , Ota Chihiro , Yoneda Takeshi , Tahara Shigeyuki , Maki Nobukazu , Matsuura Takahiro , Sekiguchi Masahiro , Itoigawa Yoshiaki , Tateishi Tomohiko , Kaneko Kazuo
Published: November 2017

Objectives

To characterise the tackler’s head position during one-on-one tackling in rugby and to determine the incidence of head, neck and shoulder injuries through analysis of game videos, injury records and a questionnaire completed by the tacklers themselves.

Methods

We randomly selected 28 game videos featuring two university teams in competitions held in 2015 and 2016. Tackles were categorised according to tackler’s head position. The ‘pre-contact phase’ was defined; its duration and the number of steps taken by the ball carrier prior to a tackle were evaluated.

Results

In total, 3970 tackles, including 317 (8.0%) with the tackler’s head incorrectly positioned (ie, in front of the ball carrier) were examined. Thirty-two head, neck or shoulder injuries occurred for an injury incidence of 0.8% (32/3970). The incidence of injury in tackles with incorrect head positioning was 69.4/1000 tackles; the injury incidence with correct head positioning (ie, behind or to one side of the ball carrier) was 2.7/1000 tackles. Concussions, neck injuries, ‘stingers’ and nasal fractures occurred significantly more often during tackles with incorrect head positioning than during tackles with correct head positioning. Significantly fewer steps were taken before tackles with incorrect head positioning that resulted in injury than before tackles that did not result in injury.

Conclusion

Tackling with incorrect head position relative to the ball carrier resulted in a significantly higher incidence of concussions, neck injuries, stingers and nasal fractures than tackling with correct head position. Tackles with shorter duration and distance before contact resulted in more injuries.