bluuebunny/crossref_metadata_2025 huggingface dataset:
Multispecies comparisons of adaptability to climate change: A role for life‐history characteristics?
Authors: Saalfeld Sarah T. , Lanctot Richard B.
Published: November 2017

Phenological advancement allows individuals to adapt to climate change by timing life‐history events to the availability of key resources so that individual fitness is maximized. However, different trophic levels may respond to changes in their environment at different rates, potentially leading to a phenological mismatch. This may be especially apparent in the highly seasonal arctic environment that is experiencing the effects of climate change more so than any other region. During a 14‐year study near Utqiaġvik (formerly Barrow), Alaska, we estimated phenological advancement in egg laying in relation to snowmelt for eight arctic‐breeding shorebirds and investigated potential linkages to species‐specific life‐history characteristics. We found that snowmelt advanced 0.8 days/year—six times faster than the prior 60‐year period. During this same time, six of the eight species exhibited phenological advancement in laying dates (varying among species from 0.1 to 0.9 days earlier per year), although no species appeared capable of keeping pace with advancing snowmelt. Phenological changes were likely the result of high phenotypic plasticity, as all species investigated in this study showed high interannual variability in lay dates. Commonality among species with similar response rates to timing of snowmelt suggests that nesting later and having an opportunistic settlement strategy may increase the adaptability of some species to changing climate conditions. Other life‐history characteristics, such as migration strategy, previous site experience, and mate fidelity did not influence the ability of individuals to advance laying dates. As a failure to advance egg laying is likely to result in greater phenological mismatch, our study provides an initial assessment of the relative risk of species to long‐term climatic changes.
Enantioselective Synthesis of 2,3‐Dihydrofurans via Ammonium Ylides
Authors: Worgull Dennis , Öhler Laura , Strache Joss Pepe , Friedrichs Teresa , Ullrich Patrick
Published: November 2017

A chiral, ammonium ylide based access to tetrasubstituted 2,3‐dihydrofurans starting from readily available benzylidene dicarbonyls and bromo acetophenones has been developed. The products are obtained in moderate to good yields with excellent diasteroselectivity and good to excellent enantioselectivity (up to 99:1 e.r.). The employed chiral amine can be recovered in near quantitative yield. The transformation can be run as a three‐component one‐pot reaction, generating the ammonium salt and ylide in situ. The scope of this reaction includes 17 new dihydrofurans with aromatic or heteroaromatic substituents.
Long reaction times are associated with delayed brain activity in lewy body dementia
Authors: Firbank Michael J. , O'Brien John T. , Taylor John Paul
Published: November 2017

A significant symptom of Lewy body dementia (LBD) is slow cognitive processing or bradyphrenia. In a previous fMRI task‐based study, we found slower responses in LBD, accompanied by greater deactivation in the default mode network. In this study, we investigated the timing and magnitude of the activations and deactivations with respect to reaction time to determine whether the slower responses in LBD were associated with delayed neuronal activity. Using fMRI, we examined the magnitude and latency of activations and deactivations during an event‐related attention task in 32 patients with LBD and 23 healthy controls using predefined regions of interest. Default mode network deactivations did not significantly differ in their timing between groups or task conditions, while the task‐related activations in the parietal, occipital, frontal, and motor cortex were all significantly later in the LBD group. Repeating the analysis with reaction time as a parametric modulator of activation magnitude produced similar findings, with the reaction time modulator being significant in a number of regions including the default mode network, suggesting that the increased deactivation in LBD is partly explained by slower task completion. Our data suggest that the default mode network deactivation is initiated at the start of the task, and remains deactivated until its end, with the increased magnitude of deactivation in LBD reflecting the more prolonged cognitive processing in these patients. These data add substantially to our understanding of the neural origins of bradyphrenia, which will be essential for determining optimum therapeutic strategies for cognitive impairment in LBD. Hum Brain Mapp 39:633–643, 2018. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
Surface based electrode localization and standardized regions of interest for intracranial EEG
Authors: Trotta Michael S. , Cocjin John , Whitehead Emily , Damera Srikanth , Wittig John H. , Saad Ziad S. , Inati Sara K. , Zaghloul Kareem A.
Published: November 2017

Intracranial recordings captured from subdural electrodes in patients with drug resistant epilepsy offer clinicians and researchers a powerful tool for examining neural activity in the human brain with high spatial and temporal precision. There are two major challenges, however, to interpreting these signals both within and across individuals. Anatomical distortions following implantation make accurately identifying the electrode locations difficult. In addition, because each implant involves a unique configuration, comparing neural activity across individuals in a standardized manner has been limited to broad anatomical regions such as cortical lobes or gyri. We address these challenges here by introducing a semi‐automated method for localizing subdural electrode contacts to the unique surface anatomy of each individual, and by using a surface‐based grid of regions of interest (ROIs) to aggregate electrode data from similar anatomical locations across individuals. Our localization algorithm, which uses only a postoperative CT and preoperative MRI, builds upon previous spring‐based optimization approaches by introducing manually identified anchor points directly on the brain surface to constrain the final electrode locations. This algorithm yields an accuracy of 2 mm. Our surface‐based ROI approach involves choosing a flexible number of ROIs with different spatial resolutions. ROIs are registered across individuals to represent identical anatomical locations while accounting for the unique curvature of each brain surface. This ROI based approach therefore enables group level statistical testing from spatially precise anatomical regions.
When global rule reversal meets local task switching: The neural mechanisms of coordinated behavioral adaptation to instructed multi‐level demand changes
Authors: Shi Yiquan , Wolfensteller Uta , Schubert Torsten , Ruge Hannes
Published: November 2017

Cognitive flexibility is essential to cope with changing task demands and often it is necessary to adapt to combined changes in a coordinated manner. The present fMRI study examined how the brain implements such multi‐level adaptation processes. Specifically, on a “local,” hierarchically lower level, switching between two tasks was required across trials while the rules of each task remained unchanged for blocks of trials. On a “global” level regarding blocks of twelve trials, the task rules could reverse or remain the same. The current task was cued at the start of each trial while the current task rules were instructed before the start of a new block. We found that partly overlapping and partly segregated neural networks play different roles when coping with the combination of global rule reversal and local task switching. The fronto‐parietal control network (FPN) supported the encoding of reversed rules at the time of explicit rule instruction. The same regions subsequently supported local task switching processes during actual implementation trials, irrespective of rule reversal condition. By contrast, a cortico‐striatal network (CSN) including supplementary motor area and putamen was increasingly engaged across implementation trials and more so for rule reversal than for nonreversal blocks, irrespective of task switching condition. Together, these findings suggest that the brain accomplishes the coordinated adaptation to multi‐level demand changes by distributing processing resources either across time (FPN for reversed rule encoding and later for task switching) or across regions (CSN for reversed rule implementation and FPN for concurrent task switching).
Functional dysconnectivity of the limbic loop of frontostriatal circuits in first‐episode, treatment‐naive schizophrenia
Authors: Lin Pan , Wang Xiaosheng , Zhang Bei , Kirkpatrick Brian , Öngür Dost , Levitt James J. , Jovicich Jorge , Yao Shuqiao , Wang Xiang
Published: November 2017

Frontostriatal circuits dysfunction has been implicated in the etiology and psychopathology of patients with schizophrenia (SZ). However, few studies have investigated SZ‐related functional connectivity (FC) alterations in discrete frontostriatal circuits and their relationship with pathopsychology in first‐episode schizophrenia (FESZ). The goal of this study was to identify dysfunctions in discrete frontostriatal circuits that are associated with key features of FESZ. To this end, a case–control, cross‐sectional study was conducted, wherein resting‐state (RS) functional magnetic resonance (fMRI) data were collected from 37 treatment‐naïve FESZ patients and 29 healthy control (HC) subjects. Seed‐based FC analyses were performed by placing six bilateral pairs of seeds within a priori defined subdivisions of the striatum. We observed significantly decreased FC for the FESZ group relative to the HC group [p < .05, family‐wise error (FWE)‐corrected] in the limbic loop, but not in the sensorimotor or associative loops, of frontostriatal circuitry. Moreover, bilaterally decreased inferior ventral striatum/nucleus accumbens (VSi)‐dorsal anterior cingulate cortex (dACC) FC within the limbic loop correlated inversely with overall FESZ symptom severity and the disorganization factor score of PANSS. These findings provide new insight into the role of frontostriatal limbic loop hypoconnectivity in early‐stage schizophrenia pathology and suggest potential novel therapeutic targets.
Cesarean rates and severe maternal and neonatal outcomes according to the Robson 10‐Group Classification System in Khon Kaen Province, Thailand
Authors: Kankoon Natthapong , Lumbiganon Pisake , Kietpeerakool Chumnan , Sangkomkamhang Ussanee , Betrán Ana P. , Robson Michael
Published: November 2017

Objective

To assess cesarean rates and maternal and neonatal outcomes in each group in the Robson 10‐Group Classification System (TGCS).

Methods

In a cross‐sectional study, data were reviewed from all pregnant women who delivered at 24 government hospitals in Khon Kaen Province, Thailand, in 2014. Delivery and perinatal outcomes were recorded.

Results

Of 18 043 deliveries, 5666 (31.4%) were by cesarean. Women in group 5 (previous cesarean) accounted for the most cesareans (1472, 26.0%). Groups 1 and 2 (nulliparous women) accounted for 2355 (41.6%) of procedures; the rate of cesarean within these two groups was 19.4% (1162/5981) and 71.2% (1193/1675), respectively. As compared with group 1, women in groups 2, 4, 6, 7, and 10 had significantly increased risk of severe maternal outcomes, and those in groups 6, 7, 8, 9, and 10 had an increased risk of severe neonatal outcomes.

Conclusion

The rate of cesarean in the study setting was high, and three out of four procedures were performed for women in groups 5, 1, and 2. Interventions should be focused on these groups to reduce the overall cesarean rates.
Overlapping Groundwater Service Markets in a Palm Grove in the Algerian Sahara
Authors: Hamamouche Meriem Farah , Kuper Marcel , Hartani Tarik , Bouarfa Sami
Published: November 2017

Groundwater service markets are important and dynamic institutions that provide water to a wide range of farmers in many regions. However, these institutions represent arenas of complex and often antagonistic relations, which determine which farmers gain access to water and how. This study analyses the emergence and functioning of groundwater service markets from a historical perspective to advance the understanding of the role of social power games in shaping these institutions. The study was conducted in the Sidi Okba oasis in the Algerian Sahara, where over recent decades, four (in)formal, often overlapping, groundwater service markets have emerged. These markets were shaped progressively by socio‐ethnic antagonism, state intervention and economic competition between water sellers. By continuously adjusting these institutions, the highly diverse irrigation community prevented the emergence of a monopoly in groundwater sales and maintained the balance of power between water sellers and buyers by countering possible control of groundwater access by a single socio‐ethnic or economic group. The demonstrated ability of the irrigation community to craft rules to ensure these groundwater service markets function should encourage public actors to mobilize this capacity to deal with the drop in water tables, which is one adverse outcome of the ‘success' of these markets. Copyright © 2020 John Wiley & Sons, Ltd.
The potential of microRNAs as human prostate cancer biomarkers: A meta‐analysis of related studies
Authors: Song Chun‐Jiao , Chen Huan , Chen Li‐Zhong , Ru Guo‐Mei , Guo Jian‐Jun , Ding Qian‐Nan
Published: November 2017

Prostate cancer (PC) is a very important kind of male malignancies. When PC evolves into a stage of hormone resistance or metastasis, the fatality rate is very high. Currently, discoveries and advances in miRNAs as biomarkers have opened the potential for the diagnosis of PC, especially early diagnosis. miRNAs not only can noninvasively or minimally invasively identify PC, but also can provide the data for optimization and personalization of therapy. Moreover, miRNAs have been shown to play an important role to predict prognosis of PC. The purpose of this meta‐analysis is to integrate the currently published expression profile data of miRNAs in PC, and evaluate the value of miRNAs as biomarkers for PC. All of relevant records were selected via electronic databases: Pubmed, Embase, Cochrane, and CNKI based on the assessment of title, abstract, and full text. we extracted mean ± SD or fold change of miRNAs expression levels in PC versus BPH or normal controls. Pooled hazard ratios (HRs) with 95% confidence intervals (CI) for overall survival (OS) and recurrence‐free survival (RFS), were also calculated to detect the relationship between high miRNAs expression and PC prognosis. Selected 104 articles were published in 2007‐2017. According to the inclusion criteria, 104 records were included for this meta‐analysis. The pooled or stratified analyze showed 10 up‐regulated miRNAs (miR‐18a, miR‐34a, miR‐106b, miR‐141, miR‐182, miR‐183, miR‐200a/b, miR‐301a, and miR‐375) and 14 down‐regulated miRNAs (miR‐1, miR‐23b/27b, miR‐30c, miR‐99b, miR‐139‐5p, miR‐152, miR‐187, miR‐204, miR‐205, miR‐224, miR‐452, miR‐505, and let‐7c) had relatively good diagnostic and predictive potential to discriminate PC from BPH/normal controls. Furthermore, high expression of miR‐32 and low expression of let‐7c could be used to differentiate metastatic PC from local/primary PC. Additional interesting findings were that the expression profiles of five miRNAs (miR‐21, miR‐30c, miR‐129, miR‐145, and let‐7c) could predict poor RFS of PC, while the evaluation of miR‐375 was associated with worse OS. miRNAs are important regulators in PC progression. Our results indicate that miRNAs are suitable for predicting the different stages of PC. The detection of miRNAs is an effective way to control patient's prognosis and evaluate therapeutic efficacy. However, large‐scale detections based on common clinical guidelines are still necessary to further validate our conclusions, due to the bias induced by molecular heterogeneity and differences in study design and detection methods.
Electrostatics for probing lone pairs and their interactions
Authors: Bijina Padinjare Veetil , Suresh Cherumuttathu H. , Gadre Shridhar R.
Published: November 2017

The value of the molecular electrostatic potential minimum (Vmin) and its topographical features (position, as well as the eigenvalues and eigenvectors of the corresponding Hessian matrix) are recently proposed as the criteria for characterizing a lone pair (Kumar A. et al., J. Phys. Chem. 2014, A118, 526). This electrostatic characterization of lone pairs is examined for a large number of small molecules employing MP4/6‐311++G(d,p)//MP2/6‐311++G(d,p) theory. The eigenvector of the Hessian matrix corresponding to its largest eigenvalue (λmax), is found to be directed toward the lone pair‐bearing‐atom, with λmax showing a strong linear correlation with Vmin. Large magnitudes of Vmin and λmax indicate a charge‐dense lone pair. The topographical features of Vmin are seen to provide insights into the interactive behavior of the molecules with model electrophiles, viz. HF, CO2, and Li+. In all the complexes of HF and majority of the other complexes, the interaction energy (Eint) correlates well with the respective Vmin, value, but for some deviations occurring due to other competing secondary interactions. The electrostatic interactions are found to be highly directional in nature as the orientation of interacting atom correlates strongly to the position of lone pair. In summary, the present study on a large number of test molecules shows that electrostatics is able to probe lone pairs in molecules and offers a simple interpretation of chemical reactivity. © 2017 Wiley Periodicals, Inc.
Low‐protein diet for conservative management of chronic kidney disease: a systematic review and meta‐analysis of controlled trials
Authors: Rhee Connie M. , Ahmadi Seyed‐Foad , Kovesdy Csaba P. , Kalantar‐Zadeh Kamyar
Published: November 2017

Background

Recent data pose the question whether conservative management of chronic kidney disease (CKD) by means of a low‐protein diet can be a safe and effective means to avoid or defer transition to dialysis therapy without causing protein‐energy wasting or cachexia. We aimed to systematically review and meta‐analyse the controlled clinical trials with adequate participants in each trial, providing rigorous contemporary evidence of the impact of a low‐protein diet in the management of uraemia and its complications in patients with CKD.

Methods

We searched MEDLINE (PubMed) and other sources for controlled trials on CKD to compare clinical management of CKD patients under various levels of dietary protein intake or to compare restricted protein intake with other interventions. Studies with similar patients, interventions, and outcomes were included in the meta‐analyses.

Results

We identified 16 controlled trials of low‐protein diet in CKD that met the stringent qualification criteria including having 30 or more participants. Compared with diets with protein intake of >0.8 g/kg/day, diets with restricted protein intake (<0.8 g/kg/day) were associated with higher serum bicarbonate levels, lower phosphorus levels, lower azotemia, lower rates of progression to end‐stage renal disease, and a trend towards lower rates of all‐cause death. In addition, very‐low‐protein diets (protein intake <0.4 g/kg/day) were associated with greater preservation of kidney function and reduction in the rate of progression to end‐stage renal disease. Safety and adherence to a low‐protein diet was not inferior to a normal protein diet, and there was no difference in the rate of malnutrition or protein‐energy wasting.

Conclusions

In this pooled analysis of moderate‐size controlled trials, a low‐protein diet appears to enhance the conservative management of non‐dialysis‐dependent CKD and may be considered as a potential option for CKD patients who wish to avoid or defer dialysis initiation and to slow down the progression of CKD, while the risk of protein‐energy wasting and cachexia remains minimal.
Intra‐annual rainfall variability in the Spanish hydrographic basins
Authors: García‐Barrón L. , Aguilar‐Alba M. , Morales J. , Sousa A.
Published: November 2017

Understanding the intra‐annual distribution of rainfall is an important element for climatic classification and serves as a basis for natural resources management. The present study analyses multi‐annual irregularities of the rainfall distribution throughout the year in the period 1941–2010, in the hydrographic basins of the Iberian Peninsula. In order to analyse its variation, the rainfall centralisation and dispersion parameters throughout the annual cycle were previously defined and calculated for each year. Inter‐annual series of both parameters were generated, which allowed detecting their temporal behaviour in each of the basins and relating differentiated geographic areas. Independent of the total annual rainfall, greater temporal simultaneity is observed in the fluctuations of the intra‐annual parameter ‘centralisation’ in the Atlantic basins and wider inter‐annual oscillations in the Mediterranean basins. Around the year 1970, there was a displacement in the predominance of autumn rains, although the process is inverted in the last decades. Also from the decade of 1970 there is a general increase in the inter‐annual variability of the ‘dispersion’ parameter, especially in the basins that drain towards the Atlantic Ocean. The ‘dispersion’ parameter allows detecting latitudinal (Cantabrian vs. Guadalquivir) and longitudinal (Atlantic vs. Mediterranean) patterns of intra‐annual rainfall distribution irregularity in the Iberian Peninsula. The results obtained are also associated to atmospheric general circulation patterns of the North Atlantic Oscillation and the Western Mediterranean Oscillation. The monthly winter values of the North Atlantic Oscillation present a marked influence on dispersion, especially in the basins that discharge into the Atlantic Ocean, which show a double gradient: decreasing longitudinally from the Atlantic coast to the Mediterranean coast and latitudinally from north to south.
­­­Mechanosensitivity of aged muscle stem cells
Authors: Boers Heleen E. , Haroon Mohammad , Le Grand Fabien , Bakker Astrid D. , Klein‐Nulend Jenneke , Jaspers Richard T.
Published: November 2017

During aging, skeletal muscle tissue progressively declines in mass, strength, and regenerative capacity. Decreased muscle stem cell (MuSC) number and impaired function might underlie the aging‐related muscle wasting and impaired regenerative capacity. As yet, the search for factors that regulate MuSC fate and function has revealed several biochemical factors within the MuSC niche that may be responsible for the decline in MuSC regenerative capacity. This decline cannot be explained by environmental factors solely, as the MuSC potential to regenerate muscle tissue is not reversed by changing the biochemical MuSC niche composition. Here we discuss the likeliness that during physical exercise, MuSCs within their niche are subjected to mechanical loads, in particular pressure and shear stress, as well as associated deformations. We postulate that these physical cues are involved in the activation and differentiation of MuSCs as these cells contain several transmembrane sensor proteins that have been shown to be mechanosensitive in other cell types, that is, endothelial cells and osteoprogenitors. We will specifically address age‐related changes in mechanosensing in MuSCs and their niche. Insight in the physical cues applied to the MuSCs in vivo, and how these cues affect MuSC fate and function, helps to develop new therapeutic interventions to counterbalance age‐related muscle loss. This requires an approach combining two‐ and three‐dimensional live cell imaging of MuSCs within contracting muscle tissue, mathematical finite element modeling, and cell biology. © 2017 The Authors. Journal of Orthopaedic Research® Published by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 36:632–641, 2018.
Regioisomeric distribution of 9‐ and 13‐hydroperoxy linoleic acid in vegetable oils during storage and heating
Authors: Pignitter Marc , Zaunschirm Mathias , Lach Judith , Unterberger Laura , Kopic Antonio , Keßler Claudia , Kienesberger Julia , Pischetsrieder Monika , Eggersdorfer Manfred , Riegger Christoph , Somoza Veronika
Published: November 2017

BACKGROUND

The oxidative deterioration of vegetable oils is commonly measured by the peroxide value, thereby not considering the contribution of individual lipid hydroperoxide isomers, which might have different bioactive effects. Thus, the formation of 9‐ and 13‐hydroperoxy octadecadienoic acid (9‐HpODE and 13‐ HpODE), was quantified after short‐term heating and conditions representative of long‐term domestic storage in samples of linoleic acid, canola, sunflower and soybean oil, by means of stable isotope dilution analysis–liquid chromatography‐mass spectroscopy.

RESULTS

Although heating of pure linoleic acid at 180 °C for 30 min led to an almost complete loss of 9‐HpODE and 13‐HpODE, heating of canola, sunflower and soybean oil resulted in the formation of 5.74 ± 3.32, 2.00 ± 1.09, 16.0 ± 2.44 mmol L–1 13‐HpODE and 13.8 ± 8.21, 10.0 ± 6.74 and 45.2 ± 6.23 mmol L–1 9‐HpODE. An almost equimolar distribution of the 9‐ and 13‐HpODE was obtained during household‐representative storage conditions after 56 days, whereas, under heating conditions, an approximately 2.4‐, 2.8‐ and 5.0‐fold (P ≤ 0.001) higher concentration of 9‐HpODE than 13‐HpODE was detected in canola, soybean and sunflower oil, respectively.

CONCLUSION

A temperature‐dependent distribution of HpODE regioisomers could be shown in vegetable oils, suggesting their application as markers of lipid oxidation in oils used for short‐term heating. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Minimally invasive surgery and enhanced recovery after surgery: The ideal combination?
Authors: Pache Basile , Hübner Martin , Jurt Jonas , Demartines Nicolas , Grass Fabian
Published: October 2017

Enhanced recovery after surgery (ERAS) and minimally invasive surgery are both in the limelight due to their potential positive effects on surgical outcome. Large randomized trials and meta‐analyses validated the use of both, laparoscopy and ERAS protocol, as individual measures. A synergistic effect of both entities might contribute to even better outcomes. This review hence assessed the literature upon up‐to‐date studies combining both methods.
Thirty‐five years of single surgeon experience in the reconstruction of esophagus and voice with free ileocolon flap following total pharyngolaryngectomy
Authors: Chen Hung‐Chi , Ciudad Pedro , Chen Shih‐Heng , Agko Mouchammed
Published: November 2017

Background

Several surgical options exist for the reconstruction of total pharyngolaryngectomy defect. The purpose of this report is to present our experience with ileocolon flap for simultaneous reconstruction of both esophagus and voice.

Methods

Demographic data, clinical information, and outcomes of 205 patients who underwent the ileocolon flap procedure over the last 35 years were examined. Preoperative evaluation, intraoperative details, and postoperative management were analyzed. The types of additional procedures performed to improve outcomes were explored.

Results

Of the 205 patients, 191 had a free ileocolon flap and the remaining 14 a pedicled flap. Ninety‐seven percent of the flaps were successful with a fistula rate of 5.4%. Seven patients required reexploration and six flaps failed. Seventy‐eight percent of the patients reported their swallowing function to be very good to excellent. Speech function was rated as good in 64% of patients and moderate in 21%. Three patients develop bowel obstruction, two of which required enterolysis. Five patients had postoperative diarrhea that responded to conservative measures.

Conclusion

Reconstruction of pharyngoesophageal defects with ileocolon flap permits resumption of swallowing and production of speech without the need for voice prosthesis and with minimal complications.
Determination of cannabinoids from a surrogate hops matrix using multiple reaction monitoring gas chromatography with triple quadrupole mass spectrometry
Authors: Leghissa Allegra , Hildenbrand Zacariah L. , Foss Frank W. , Schug Kevin A.
Published: November 2017

Cannabinoids are the primary bioactive constituents of Cannabis sativa and Cannabis indica plants. In this work, gas chromatography in conjunction with triple quadrupole mass spectrometry in multiple reaction monitoring mode was explored for determination of cannabinoids from a surrogate hops matrix. Gas chromatography with mass spectrometry is a reasonable choice for the analysis of these compounds; however, such methods are susceptible to false positives for Δ9‐tetrahydrocannabinol, due to decarboxylation of Δ9‐tetrahydrocannabinolic acid, its acid precursor, in the hot injection port. To avoid this transformation, the carboxyl group of Δ9‐tetrahydrocannabinolic acid was protected through a silylation reaction. Multiple reaction monitoring transitions for both unmodified and silylated cannabinoids were developed and the fragmentation pathways for the different species were assigned. Precision and accuracy were evaluated for cannabinoids spiked into hops at different levels. The developed methods provided good linearity (R2 > 0.99) for all the cannabinoids with a linear range from 0.15 to 20 mg/L, and with limits of detection in the orders of low‐ to mid‐picogram on column. The recoveries for the cannabinoids were generally between 75 and 120%. Precisions (<6% coefficient of variation) were within acceptable ranges.
Risk factors of pediatric tinnitus: Systematic review and meta‐analysis
Authors: Lee Doh Young , Kim Young Ho
Published: November 2017

Objectives/Hypothesis

Medications for pediatric tinnitus are not widely used due to a lack of evidence‐based information. The modification of risk factors is essential in pediatric tinnitus; however, there is a lack of systematic reviews despite several reports on risk factors. This study performed a systematic review and meta‐analysis of available literature to evaluate risk factors of pediatric tinnitus.

Methods

Studies reporting the risk factors of pediatric tinnitus were systematically reviewed by searching the MEDLINE, PubMed, and Embase databases for studies published from database inception to 2016. The selected articles included clinical or epidemiological studies conducted with at least 50 subjects and at least one risk factor, including age, gender, hearing loss, noise exposure, or smoking.

Results

Eleven studies involving a total of 28,358 individuals were identified. Increased age was not a significant risk factor with a standardized median difference of 0.16 (95% confidence interval [CI]: −0.01 to 0.33). However, there was a significant correlation between increased age and tinnitus in the adolescent population. The odds ratio (OR) was 1.37 for female gender (95% CI: 1.17 to 1.60), 2.39 for hearing loss (95% CI: 1.48 to 3.87), and 11.35 for noise exposure (95% CI: 1.87 to 68.77). Two studies in adolescents showed statistical significance for smoking as a risk factor in developing tinnitus (OR: 6.05, 95% CI: 1.81 to 20.21).

Conclusions

Older‐aged adolescents, as well as those who are females and those with hearing loss may have a higher risk of tinnitus. Noise exposure in the general pediatric population and smoking in adolescents may represent especially important risk factors in pediatric tinnitus. Laryngoscope, 128:1462–1468, 2018
Transductive Ridge Regression in Structure‐activity Modeling
Authors: Marcou Gilles , Delouis Grace , Mokshyna Olena , Horvath Dragos , Lachiche Nicolas , Varnek Alexandre
Published: November 2017

In this article we consider the application of the Transductive Ridge Regression (TRR) approach to structure‐activity modeling. An original procedure of the TRR parameters optimization is suggested. Calculations performed on 3 different datasets involving two types of descriptors demonstrated that TRR outperforms its non‐transductive analogue (Ridge Regression) in more than 90 % of cases. The most significant transductive effect was observed for small datasets. This suggests that transduction may be particularly useful when the data are expensive or difficult to collect.
Dietary Vitamin K and Association with Hepatic Vitamin K Status in a Yup'ik Study Population from Southwestern Alaska
Authors: Au Nicholas T. , Ryman Tove , Rettie Allan E. , Hopkins Scarlett E. , Boyer Bert B. , Black Jynene , Philip Jacques , Yracheta Joseph , Fohner Alison E. , Reyes Morayma , Thornton Timothy A. , Austin Melissa A. , Thummel Kenneth E.
Published: November 2017

Scope

The relationship between dietary vitamin K and plasma PIVKA‐II concentration, a biomarker of hepatic vitamin K status, in a Yup'ik study population in southwestern Alaska is investigated.

Methods and results

A total of 659 male and female, self‐reported Yup'ik people, ≥14 years of age, were enrolled. Blood is collected for genotyping and plasma PIVKA‐II biomarker analysis. A Yup'ik‐specific dietary food frequency questionnaire is used to assess vitamin K intake. Among the participants, 22% report not consuming foods rich in vitamin K during the past year and 36% have a PIVKA‐II concentration ≥ 2 ng mL–1, indicating vitamin K insufficiency. The odds of an elevated PIVKA‐II concentration are 33% lower in individuals reporting any versus no consumption of vitamin‐K‐rich foods. The association is significant after adjusting for CYP4F2*3 genotype. Tundra greens are high in vitamin K1 content, but an exploratory analysis suggests that subsistence meat sources have a greater effect on vitamin K status.

Conclusions

A substantial proportion of the Yup'ik population exhibits vitamin K insufficiency, which is associated with low consumption of vitamin K rich foods and which might affect an individual's response to anticoagulant drugs such as warfarin that target the vitamin K cycle.
Strategic philanthropy and its challenges in India: A multiple case study of grantmaking organizations
Authors: Chatterjee Anusha , Rai Abha
Published: November 2017

Grantmaking organizations in the United States play an increasingly important role in philanthropic giving toward international development issues. Champions of strategic philanthropy have encouraged grantmakers to set clear goals, use evidence‐based strategies, and monitor programs. This exploratory study delves into grantmaking in one of the largest emerging economies; India. Although India is a major recipient of private philanthropy, it continues to perform below average on various socio‐economic indicators. The impact of grantmaking has been unclear. We conducted in‐depth interviews with managers and leaders (n = 9) engaged in decision‐making within U.S. based grantmaking organizations, including nonprofit intermediaries and philanthropic foundations. We examine how the concept of strategic philanthropy is operationalized by participant organizations. Although the participants acknowledge the importance of starting out with a well‐defined strategy, they also face several challenges. We identify some of these challenges, outline how they are being addressed, and discuss implications.
Cyclometalated Pt complex based random terpolymers as electron acceptors for all polymer solar cells
Authors: Gao Xuyu , Wang Menghan , Cao Xudong , Yang Jie , Zhong Yu , Zhang Zhiguo , Li Cheng , Huettner Sven , Tao Youtian , Li Yongfang , Huang Wei
Published: November 2017

Various molar ratios of platinum complexes were introduced into the conjugated backbone of the well‐studied poly[[N,N′‐bis(2‐octyldodecyl)‐naphthalene‐1,4,5,8‐bis(dicarboximide)‐2,6‐diyl]‐alt‐5,5′‐(2,2′‐bithiophene)](PNDIT2) acceptor polymer through random terpolymer approach. Terpolymers PNDIT2Ptx (x = 1, 2 and 5) exhibited slightly higher melting point (Tm), crystallization temperature, HOMO and LUMO energy levels than the control PNDIT2 copolymer due to the introduction of small amount of weaker electron‐withdrawing bulky rigid Pt complex instead of strong electron‐withdrawing flexible naphthalene diimide. When blended them with poly[[2,6′‐4,8‐di(5‐ethylhexylthienyl)benzo[1,2‐b;3,3‐b] dithiophene] [3‐fluoro‐2[(2‐ethylhexyl)carbonyl]thieno[3,4‐b]thiophenediyl]] (PTB7‐Th) in all polymer solar cells, enhanced power conversion efficiency of 4.51% (3.74%) was obtained in terpolymer PNDIT2Pt1 based device compared to 3.88% (3.24%) of the control PNDIT2 at the same inverted (conventional) device conditions. The enhancement was probably ascribed to higher hole and electron transport ability and more efficient charge separation. To the best of our knowledge, this is the first example of random terpolymer acceptors based on heavy metal complexes. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 105–115
Molecular weight dependence of carrier mobility and recombination rate in neat P3HT films
Authors: Dixon Alex G. , Visvanathan Rayshan , Clark Noel A. , Stingelin Natalie , Kopidakis Nikos , Shaheen Sean E.
Published: November 2017

The microstructure dependence of carrier mobility and recombination rates of neat films of poly 3‐hexylthyophene (P3HT) were determined for a range of materials of weight‐average molecular weights,Mw, ranging from 14 to 331 kDa. This variation has previously been shown to modify the polymer microstructure, with low molecular weights forming a one‐phase, paraffinic‐like structure comprised of chain‐extended crystallites, and higher molecular weights forming a semicrystalline structure with crystalline domains being embedded in an amorphous matrix. Using Charge Extraction by Linearly Increasing Voltage (CELIV), we show here that the carrier mobility in P3HT devices peaks for materials ofMw = 48 kDa, and that the recombination rate decreases monotonically with increasing molecular weight. This trend is likely due to the development of a semicrystalline, two‐phase structure with increasingMw, which allows for the spatial separation of holes and electrons into the amorphous and crystalline regions, respectively. This separation leads to decreased recombination. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2018,56, 31–35
Liprotides assist in folding of outer membrane proteins
Authors: Nedergaard Pedersen Jannik , Skov Pedersen Jan , Otzen Daniel E.
Published: November 2017

Proteins and lipids can form complexes called liprotides, in which the partially denatured protein forms a shell encasing a lipid core. This effectively stabilizes a lipid micelle in an aqueous solvent and suggests that liprotides may provide a suitable vessel for membrane proteins. Accordingly we have investigated if liprotides consisting of α‐lactalbumin and oleate could aid folding of four different outer membrane proteins (OMPs) tOmpA, PagP, BamA, and OmpF. tOmpA was able to fold in the presence of the liprotide, and folding did not occur if only oleate or α‐lactalbumin were added. Although the liprotides did not fold the other three OMPs on its own, it was able to assist their folding in the presence of vesicles. Incubation with liprotides before folding into vesicles increased the folding yield of the outer membrane proteins to a level higher than using micelles of the non‐ionic surfactant DDM. Even though the liprotide was stable at both high urea concentrations and high pH, it failed to efficiently fold OmpA at high pH. Instead, optimal folding was seen at pH 8–9, suggesting that important changes in the liprotide occurred when increasing the pH. We conclude that an otherwise folding‐inactive fatty acid can be activated when presented by a liprotide and thereby work as an in vitro chaperone for outer membrane proteins.
Editorial introduction: New European youth mobilities
Authors: King Russell , Williams Allan M.
Published: November 2017

This paper introduces and sets the context for a special issue on “New European Youth Mobilities: Motivations, Experiences and Future Prospects,” which derives from the European Union‐funded H2020 “YMOBILITY” project on current youth migrations and transitions across the European Union. It first introduces the YMOBILITY programme and its multimethod, comparative research effort. This is followed by a brief review of secondary data on the changing profile of youth migration and mobility in Europe. Then, we explore definitions of key terms central to the project, such as “youth,” “youth transition,” “mobility,” “skill,” and the notion of the “learning migrant”. The final part of the paper introduces the 6 articles that make up the special issue, highlighting their most significant findings and outlining their value as an integrated set that offers new insights into the role of mobile young people as students and workers within European societies.
SOFT‐SLAM: Computationally efficient stereo visual simultaneous localization and mapping for autonomous unmanned aerial vehicles
Authors: Cvišić Igor , Ćesić Josip , Marković Ivan , Petrović Ivan
Published: November 2017

Autonomous navigation of unmanned aerial vehicles (UAVs) in GPS‐denied environments is a challenging problem, especially for small‐scale UAVs characterized by a small payload and limited battery autonomy. A possible solution to the aforementioned problem is vision‐based simultaneous localization and mapping (SLAM), since cameras, due to their dimensions, low weight, availability, and large information bandwidth, circumvent all the constraints of UAVs. In this paper, we propose a stereo vision SLAM yielding very accurate localization and a dense map of the environment developed with the aim to compete in the European Robotics Challenges (EuRoC) targeting airborne inspection of industrial facilities with small‐scale UAVs. The proposed approach consists of a novel stereo odometry algorithm relying on feature tracking (SOFT), which currently ranks first among all stereo methods on the KITTI dataset. Relying on SOFT for pose estimation, we build a feature‐based pose graph SLAM solution, which we dub SOFT‐SLAM. SOFT‐SLAM has a completely separate odometry and mapping threads supporting large loop‐closing and global consistency. It also achieves a constant‐time execution rate of 20 Hz with deterministic results using only two threads of an onboard computer used in the challenge. The UAV running our SLAM algorithm obtained the highest localization score in the EuRoC Challenge 3, Stage IIa–Benchmarking, Task 2. Furthermore, we also present an exhaustive evaluation of SOFT‐SLAM on two popular public datasets, and we compare it to other state‐of‐the‐art approaches, namely ORB‐SLAM2 and LSD‐SLAM. The results show that SOFT‐SLAM obtains better localization accuracy on the majority of datasets sequences, while also having a lower runtime.
Au Nanoclusters Sensitized Black TiO2−x Nanotubes for Enhanced Photodynamic Therapy Driven by Near‐Infrared Light
Authors: Yang Dan , Gulzar Arif , Yang Guixin , Gai Shili , He Fei , Dai Yunlu , Zhong Chongna , Yang Piaoping
Published: November 2017

The low reactive oxygen species production capability and the shallow tissue penetration of excited light (UV) are still two barriers in photodynamic therapy (PDT). Here, Au cluster anchored black anatase TiO2−x nanotubes (abbreviated as Au25/B‐TiO2−x NTs) are synthesized by gaseous reduction of anatase TiO2 NTs and subsequent deposition of noble metal. The Au25/B‐TiO2−x NTs with thickness of about 2 nm exhibit excellent PDT performance. The reduction process increased the density of Ti3+ on the surface of TiO2, which effectively depresses the recombination of electron and hole. Furthermore, after modification of Au25 nanoclusters, the PDT efficiency is further enhanced owing to the changed electrical distribution in the composite, which forms a shallow potential well on the metal–TiO2 interface to further hamper the recombination of electron and hole. Especially, the reduction of anatase TiO2 can expend the light response range (UV) of TiO2 to the visible and even near infrared (NIR) light region with high tissue penetration depth. When excited by NIR light, the nanoplatform shows markedly improved therapeutic efficacy attributed to the photocatalytic synergistic effect, and promotes separation or restrained recombination of electron and hole, which is verified by experimental results in vitro and in vivo.
Parallel Markov chain Monte Carlo for Bayesian dynamic item response models in educational testing
Authors: Wei Zheng , Wang Xiaojing , Conlon Erin Marie
Published: November 2017

Bayesian dynamic item response models have been successfully used for educational testing data; these models are especially useful for individually varying and irregularly spaced longitudinal testing data. However, because of the complexity of the models and the large size of the data sets, computation time is excessive for carrying out full data analyses in practice. Here, we introduce a parallel Markov chain Monte Carlo method to speed the implementation of these Bayesian models. Using both simulation data and real educational testing data for reading ability, we demonstrate that computation time is greatly reduced for our parallel computing method versus full data analyses. The estimated error of our method is shown to be small, using common distance metrics. Our parallel computing approach can be used for other models in the Educational and Psychometric fields, including Bayesian item response theory models. Copyright © 2017 John Wiley & Sons, Ltd.
Sealed‐Bid Reverse Auction Pricing Mechanisms for Federated Satellite Systems
Authors: Pica Udrivolf , Golkar Alessandro
Published: November 2017

This paper develops a framework to simulate and evaluate pricing policies of spacecraft trading commodities, such as data routing, in a federated satellite network. Federated satellite systems allow the reallocation of underutilized assets, enabling their use as services between owners and third parties. The paper, by means of game theory, focuses on sealed‐bid reverse auction pricing schemes, benchmarks first‐price and second‐price auction strategies, and evaluates the associated trade‐offs in terms of performance and cost, and losses in Pareto efficiency introduced by system‐level operation constraints. The analysis considers an application case study for federated satellite systems operating in Low Earth Orbit for commercial purposes. Satellite federations are a novel paradigm envisioning on‐orbit opportunistic sharing of resources through an ad hoc mobile satellite network. The architecture creates the basis for the realization of a commercial cloud computing environment in orbit, with spacecraft establishing communications links between each other leveraging on system design margins. The results of the case study in space provide new insights on the design of federated satellites and their operations while characterizing emergent behaviors and efficient trade‐offs on the Pareto front of the cost–performance curve.