bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of 5% Sulfur Hexafluoride Versus 100% Air Tamponade in Descemet Membrane Endothelial Keratoplasty
Authors: Ampazas Paraskevas , Droutsas Konstantinos , Giallouros Eleftherios , Schroeder Frank M. , Sekundo Walter
Published: July 2017

Purpose:

To compare the rebubbling rate and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) with 5% sulfur hexafluoride (SF6) gas versus 100% air as a tamponade for graft attachment.

Methods:

Retrospective, comparative, interventional case series including 368 consecutive pseudophakic eyes with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy that underwent DMEK in a tertiary referral center between October 2010 and August 2015 using either air (group 1, 191 eyes) or 5% SF6 (group 2, 177 eyes) as a tamponade. The rebubbling rate, complications, best-corrected distance visual acuity (BCVA), manifest refraction, and endothelial cell density were analyzed before and at 1 week, 1, 3, 6, 12, 24, and 36 months after surgery.

Results:

The rebubbling rate was 20.4% (39/191, group 1) versus 6.8% (12/177, group 2; P < 0.001). Complications included cystoid macular edema (n = 5, group 1, and n = 10, group 2; P = 0.14) and 1 case of presumed allograft rejection (n = 1, group 2). The follow-up period was 12 ± 8 months for group 1 and 6 ± 4 months for group 2. BCVA (logarithm of the minimum angle of resolution) had improved after 12 months from 1.43 ± 0.63 to 0.18 ± 0.26 (group 1, P < 0.001) and from 1.8 ± 0.63 to 0.18 ± 0.17 (group 2, P < 0.001). The percentage of eyes with BCVA ≥0.2 logarithm of the minimum angle of resolution at 12 months was 70.9% (90/127, group 1) and 78.4% (40/51, group 2; P = 0.3). Endothelial cell loss at 12 months after DMEK was 44 ± 18% (group 1) versus 33 ± 15% (group 2, P = 0.07).

Conclusions:

The use of a tamponade with 5% SF6 yielded a significantly lower incidence of graft detachment requiring surgical reintervention with no detrimental effect on graft endothelial cells. Thus, routine use of 5% SF6 for a graft tamponade in DMEK is recommended.
Perinatal HIV Infection and Exposure and Their Association With Dental Caries in Nigerian Children
Authors: Coker Modupe , El-Kamary Samer S. , Enwonwu Cyril , Blattner William , Langenberg Patricia , Mongodin Emmanuel , Akhigbe Paul , Obuekwe Ozo , Omoigberale Austin , Charurat Manhattan
Published: July 2017

Background:

Although HIV infection is associated with well-known oral pathologies, there remains a dearth of comparative studies aimed at determining the association between HIV infection/exposure and early childhood caries.

Methods:

This is a cross-sectional study using a convenience sample of 3 groups of children receiving care at a tertiary care hospital in Nigeria. The groups include HIV infected (HI), HIV exposed but uninfected and HIV-unexposed and -uninfected children 6 through 72 months of age. Medical records were reviewed, and caregivers were interviewed for sociodemographic, maternal and birth factors as well as early feeding and dietary information. Oral examinations were performed by trained dentist examiners.

Results:

Of 335 children enrolled, 33 (9.9%) presented with caries. In an adjusted analysis, compared with HIV-unexposed and -uninfected children, HI children had significantly greater odds of having caries (odds ratio = 2.58; 95% confidence interval: 1.04–6.40; P = 0.04), but there was no statistically significant difference in HIV exposed but uninfected children (odds ratio = 2.01; 95% confidence interval: 0.56–7.23; P = 0.28). Factors significantly associated with higher caries prevalence include low CD4 counts and percentage, older age, longer duration of breastfeeding and spontaneous membrane rupture during delivery.

Conclusions:

Caries was more prevalent in HI children. These findings support the need to target HI children for oral health prevention and treatment services particularly in Nigeria and other developing countries.
Variations in Antibiotic and Azithromycin Prescribing for Children by Geography and Specialty—United States, 2013
Authors: Fleming-Dutra Katherine E. , Demirjian Alicia , Bartoces Monina , Roberts Rebecca M. , Taylor Thomas H. , Hicks Lauri A.
Published: July 2017

Background:

Using antibiotics appropriately is critical to slow spread of antibiotic resistance, a major public health problem. Children, especially young children, receive more antibiotics than other age groups. Our objective was to describe antibiotic use in children in the United States and use of azithromycin, which is recommended infrequently for pediatric conditions.

Methods:

We used QuintilesIMS Xponent 2013 data to calculate the number and rate of oral antibiotic prescriptions for children by age (0–2, 3–9 and 10–19 years) and agent. We used log-binomial regression to calculate adjusted prevalence ratios and 95% confidence intervals to determine if specialty and patient age were associated with azithromycin selection when an antibiotic was prescribed.

Results:

In 2013, 66.8 million antibiotics were prescribed to US children ≤19 years of age (813 antibiotic prescriptions per 1000 children). Amoxicillin and azithromycin were the 2 most commonly prescribed agents (23.1 million courses, 35% of all antibiotics; 12.2 million, 18%, respectively). Most antibiotics for children were prescribed by pediatricians (39%) and family practitioners (15%). Family practitioners were more likely to select azithromycin when an antibiotic was prescribed in all age groups than pediatricians (for children 0–2 years of age: prevalence ratio: 1.79, 95% confidence interval: 1.78–1.80; 3–9 years: 1.40, 1.40–1.40 and 10–19 years: 1.18, 1.18–1.18).

Conclusion:

Despite infrequent pediatric recommendations, variations in pediatric azithromycin use may suggest inappropriate antibiotic selection. Public health interventions focused on improving antibiotic selection in children as well as reducing antibiotic overuse are needed.
Compression Socks Worn During Flight and Hemostatic Balance in Boston Marathon Runners on Oral Contraceptives
Authors: Taylor Beth A. , Zaleski Amanda L. , Ballard Kevin D. , Panza Gregory A. , Fernandez Antonio B. , Corso Lauren , Pescatello Linda S. , Baggish Aaron L. , Troyanos Christopher , Thompson Paul D.
Published: July 2017

Objective:

To investigate the effect of oral contraceptive (OC) use and compression socks on hemostatic activation in women flying cross-country to and from a marathon.

Design:

Prospective study.

Setting:

2015 Boston Marathon.

Participants:

Women were divided into non-OC using (CONTROL; n = 12), OC-using (OC; n = 15), and OC-using plus compression sock (OC + SOCK; n = 14) groups.

Intervention:

Women in OC + SOCK wore compression socks during flights to and from the marathon.

Main Outcome Measures:

Venous blood samples were collected within 24 hours of arriving in Boston (EXPO), immediately after the marathon (RUN), and within 24 hours after a return flight home (Post-Flight) for analysis of thrombin–antithrombin complex (TAT), d-dimer, and tissue plasminogen activator (t-PA).

Results:

TAT did not increase with exercise (P = 0.48) and was not affected by group (P = 0.08) or the interaction between these 2 factors (P = 0.80). Group, time, and their interaction were significant for d-dimer (all P < 0.05) such that d-dimer increased with acute exercise to a greater extent (Δ d-dimer from expo to postrace = 909.5 ± 1021.9 ng/mL) in the OC + SOCK group relative to OC (Δ d-dimer = 240.0 ± 178.5 ng/mL; P = 0.02) and CONTROL (Δ d-dimer = 230.3 ± 120.3 ng/mL; P = 0.02). There was a significant effect of time, group, and the interaction on t-PA (all P < 0.01) such that t-PA increased with acute exercise to a greater extent (Δ t-PA from expo to postrace = 19.6 ± 10.0 ng/mL) in the CONTROL group relative to OC (Δ t-PA = 4.0 ± 1.8 ng/mL; P < 0.01) and OC + SOCK (Δ t-PA = 3.3 ± 1.2 ng/mL; P < 0.01).

Conclusions:

Female runners using OCs did not exhibit disproportionately increased coagulation. The use of compression socks in women on OCs, surprisingly, resulted in a greater increase in d-dimer after exercise.
Epidemiology of Injuries in Women's Lacrosse: Implications for Sport-, Level-, and Sex-Specific Injury Prevention Strategies
Authors: Barber Foss Kim D. , Le Cara Ed , McCambridge Teri , Hinton Richard Y. , Kushner Adam , Myer Gregory D.
Published: July 2017

Objective:

By the end of 2013, the United States had an estimated 278 000 female lacrosse players, with half of those participating at the youth level. The effects of the sport's rapid growth on injury rates have yet to be determined. The purpose of this clinical review is to synthesize the available published data on injuries that have occurred in the sport of women's lacrosse. Of particular interest was the risk of injury based on the level of play and position.

Data Sources:

A comprehensive literature search was performed in PubMed, High Wire Press, SPORTDiscus, Google Scholar, and Ovid using the keywords “Lacrosse Injuries,” “Epidemiology Lacrosse Injuries,” “Lacrosse Injury,” “Lacrosse,” and “Injury.”

Study Selection:

The electronic search included material published during or after 1950. In addition, all bibliographies of electronically found sources were cross-referenced to identify any additional publications that were not produced in the electronic searches.

Data Extraction:

All articles with data on women's injury rates were categorized by overall injury rates, rates by session (competition vs practice), nature of injury, location, type, severity, and player position.

Data Synthesis:

Injury rates increase with age: from youth leagues to high school and finally to the collegiate level. Rates of injury varied from 0.03 to 3.9 injuries/100 athletes. Women's game injury rates are consistently higher than practice injury rates (ranging from 0.2 to 7.1 vs 0.01 to 3.3). Injuries occur most frequently from stick-to-player or player-to-ball contact, rather than player-to-player contact. Women sustain a higher percentage of head and facial injuries relative to male lacrosse players. The most common types of injuries for women are concussions, sprains, contusions, and lacerations. More than half of all injuries are in the mild category resulting in players missing practice and games for 1 to 7 days. Offensive players had the most injuries, followed by defensive players and then midfielders, with goalies having the fewest number of injuries.

Conclusions:

In women's lacrosse, the rules and equipment used are substantially different than for the men's game. Face and hand injuries are more prevalent for women when compared with men, and ankle injuries are most prevalent in female youth. Medical professionals who treat lacrosse players can benefit from an improved understanding of the types and rates of the injuries they are likely to encounter. Improved awareness of lacrosse-specific injuries can assist these professionals to be more prepared to treat these athletes, which may lead to improved care and outcomes.
Is There a Relationship Between the Functional Movement Screen, Star Excursion Balance Test, and Balance Error Scoring System?
Authors: Harshbarger Nicole D. , Anderson Barton E. , Lam Kenneth C.
Published: July 2017

Objective:

To evaluate associations between the Functional Movement Screen (FMS), Star Excursion Balance Test (SEBT), and Balance Error Scoring System (BESS) scores.

Design:

Correlational.

Setting:

College athletic training facilities.

Participants:

Fifty-two intercollegiate athletes (men = 36 and women = 16) representing 8 sports and cleared for unrestricted sport participation.

Interventions:

Participants completed the FMS, SEBT, and BESS, in random order, during 1 testing session. Testing order was randomized to control for fatigue and learning effects.

Main Outcome Measures:

Composite and item scores for the FMS, SEBT, and BESS.

Results:

A fair, negative correlation was found between FMS asymmetry and SEBT composite (r = −0.31, P = 0.03) scores. Fair, positive correlations were reported for FMS rotary stability task and SEBT anterior (r = 0.37-0.41, P ≤ 0.007) and posteromedial (r = 0.31, P = 0.03) reaches. Fair, negative correlations were reported for FMS deep squat and BESS single-leg firm (r = −0.33, P = 0.02), double-leg foam (r = −0.34, P = 0.02) and tandem foam (r = −0.40, P = 0.003), FMS inline lunge and BESS single-leg firm (r = −0.39, P = 0.004), FMS trunk stability pushup and tandem foam (r = −0.31, P = 0.025), and FMS composite and BESS single-leg firm (r = −0.37, P = 0.007). Little-to-no correlations were reported for remaining comparisons.

Conclusions:

Results indicate that each instrument provides distinct information about function, with only small areas of overlap. Associations between the FMS asymmetry score and SEBT composite score may indicate a relationship between movement asymmetry and postural stability. Associations between the FMS deep squat and BESS foam tasks may be related to underlying neuromuscular control factors.
Fingolimod (FTY-720) is Capable of Reversing Tumor Necrosis Factor Induced Decreases in Cochlear Blood Flow
Authors: Bertlich Mattis , Ihler Friedrich , Weiss Bernhard G. , Freytag Saskia , Jakob Mark , Strupp Michael , Pellkofer Hannah , Canis Martin
Published: July 2017

Hypothesis:

The potential of Fingolimod (FTY-720), a sphingosine-1-phosphate analogue, to revoke the changes in cochlear blood flow induced by tumor necrosis factor (TNF) was investigated.

Background:

Impairment of cochlear blood flow has often been considered as the common final pathway of various inner ear pathologies. TNF, an ubiquitous cytokine, plays a major role in these pathologies, reducing cochlear blood flow via sphingosine-1-phosphate-signaling.

Methods:

Fifteen Dunkin-Hartley guinea pigs were randomly assigned to one of three groups (placebo/placebo, TNF/placebo, TNF/FTY-720). Cochlear microcirculation was quantified over 60 minutes by in vivo fluorescence microscopy before and after topical application of placebo or TNF (5 ng/ml) and after subsequent application of placebo or FTY-720 (200 μg/ml).

Results:

Treatment with TNF led to a significant decrease of cochlear blood flow.

Following this, application of placebo caused no significant changes while application of FTY-720 caused a significant rise in cochlear blood flow.

Conclusions:

FTY-720 is capable of reversing changes in cochlear blood flow induced by application of TNF. This makes FTY-720 a valid candidate for potential treatment of numerous inner ear pathologies.
The Middle Ear Cleft Status in a “Natural” Cohort With Eustachian Tube Dysfunction
Authors: Cinamon Udi , Albukrek Dov , Oron Yahav , Tamir Sharon Ovnat , Goldfarb Abraham , Dvir David , Marom Tal
Published: July 2017

Background:

The Eustachian tube (ET) has a major role in the middle ear (ME) pressure homeostasis. ET dysfunction is the accepted paradigm for pressure-related ME disorders. We studied the ME status in patients with severely diminished ET opening abilities, and anticipated to find ME disorders in most of them.

Patients and Methods:

ME status was evaluated in unconscious adults, who were hospitalized in a rehabilitation center with severe brain damage, requiring tracheotomy and gastrostomy. These patients were unable to swallow, produce valsalva, yawn, and needed oral suctioning. Examination included fiberoptic nasopharyngoscopy, gag reflex and soft palate assessments, otoscopy, and tympanometry.

Results:

Nineteen patients (38 ears) were evaluated: 14 men and 5 women, aged 18 to 93 years (average 59). Duration of gastrostomy and tracheotomy were between 3 months and 18 years. All the patients lacked gag reflex, palatal movements, or supraglottic sensation. Eighteen ears (47%) had otitis media with effusion (OME) (versus ∼3% in the general population, p = 0.00001), none had significant tympanic membrane atelectasis, but 20 (53%) ears were normal. Twenty-two ears (59%) had tympanometry types B/C and 16 (41%) had type A. Cerumen impaction incidence (26 ears, 68%) was significantly higher than in normal adults (10%), mentally retarded (36%), and nursing homes residents (57%).

Conclusions:

A dysfunctional ET predisposed ME disorders. Yet, ∼50% of the ears were normal, in contrast to the current paradigm. This implies that ME pressure homeostasis is maintained by factors that can compensate for ET dysfunction. Treating cerumen impaction and OME may be beneficial for rehabilitation.
Stable Longitudinal Performance of Adult Cochlear Implant Users for More Than 10 Years
Authors: Rak Kristen , Schraven Sebastian P. , Schendzielorz Philipp , Kurz Anja , Shehata-Dieler Wafaa , Hagen Rudolf , Radeloff Andreas
Published: July 2017

Objective:

To analyze the long-term performance of cochlear implant patients.

Study Design:

Retrospective longitudinal study.

Setting:

Tertiary referral center with a large cochlear implant program.

Main Outcome Measure:

Speech perception scores in quiet and in background noise in the short-term (1.12 ± 0.15 yr) and long-term (12.61 ± 2.34 yr) after implantation.

Patients:

Fifty-eight implanted ears from 55 patients with a mean age of 51.80 ± 1.757 years at the time of implantation were included.

Results:

Speech perception scores were stable in the long-term for up to 20 years postimplantation. When alteration of speech perception over time was investigated in relation to the age at implantation, there was a deterioration of the scores in quiet in older patients (>60 years old at the time of surgery). In addition the speech comprehension in noise was negatively correlated with the age at the time of the test.

Conclusion:

The speech perception abilities of cochlear implant users are stable in the long-term and at the most may be affected by the age of the patients, as it is known from acoustic hearing.
Clinical Practice Guidelines for Cryosurgery of Pancreatic Cancer
Authors: He Lihua , Niu Lizhi , Korpan Nikolai N. , Sumida Sajio , Xiao Yueyong , Li Jiaping , Sutedja Barlian , Lu Youyong , Zuo Jiansheng , Liu Jianguo , Xu Kecheng
Published: July 2017

Pancreatic cancer (PC), one of the most lethal malignancies, accounts for 8% to 10% of digestive system cancers, and the incidence is increasing. Surgery, chemotherapy, and radiotherapy have been the main treatment methods but are not very effective. Cryosurgery was first used in 1984 for treatment of locally advanced PC and has since become a considerable treatment for most cases of unresectable PC. During the past decade, cryosurgery has been applied in some hospitals in China, and the newly developed technique of computed tomography– and/or ultrasound-guided percutaneous cryosurgery has shown better results than chemotherapy in cases of unresectable locally advanced PC, with the 1-year survival rate reported to be more than 50%. To develop standardized criteria for the application of cryosurgery in PC, the International Society of Cryosurgery and Asian Society of Cryosurgery assembled experts from Austria, Japan, and China to discuss treatment methods and arrive at a consensus on the indications, contraindications, and preferred techniques of PC cryosurgery.
Recurrence Patterns and Long-term Results After Induction Chemotherapy, Chemoradiotherapy, and Curative Surgery in Patients With Locally Advanced Esophageal Cancer
Authors: Steffen Thomas , Dietrich Daniel , Schnider Annelies , Kettelhack Christoph , Huber Olivier , Marti Walter R. , Furrer Markus , Gloor Beat , Schiesser Marc , Thierstein Sandra , Brauchli Peter , Ruhstaller Thomas
Published: July 2017

Objective:

The long-term follow up data of 2 prospective phase II trials is reported (NCT00072033, NCT00445861), which investigated neoadjuvant chemoradiation followed by surgery in patients with esophageal carcinoma. Postoperative complications as well as prognostic factors and patterns of relapse during long-term observation are shown.

Summary of Background Data:

Long-term follow-up is often missing in the complex setting of multimodal treatments of esophageal carcinoma; this leads to rather undifferentiated follow-up guidelines for this tumor entity.

Methods:

In the first trial, patients received induction chemotherapy followed by chemoradiation and surgery. In the second trial, cetuximab was added to the same neoadjuvant treatment concomitant with induction chemotherapy and chemoradiation.

Results:

Eighty-two patients underwent surgery; the median follow-up time was 6.8 and 6.4 years, respectively. Fifty-five percent were diagnosed with adenocarcinoma, 80% clinically node-positive, 68% received transthoracic esophagectomy, and 32% transhiatal or transmediastinal resection. Five patients died postoperatively in-hospital due to complications (6%). The median overall survival was 4.3 years, and the median event-free survival was 2.7 years. Patients with adenocarcinoma rarely relapsed after a 3-year event-free survival. Whereas patients with residual tumor cells after neoadjuvant therapy primarily experienced relapse within the first 2 postoperative years, this in contrast to several patients with complete remission who also experienced late relapses 4 years after surgery.

Conclusion:

After curative surgery in a multimodal setting, the histological type and the response to neoadjuvant therapy predicted the time frame of relapse; this knowledge may influence further follow-up guidelines for esophageal carcinoma.
Racial/Ethnic Disparities in Longer-term Outcomes Among Emergency General Surgery Patients
Authors: Zogg Cheryl K. , Jiang Wei , Ottesen Taylor D. , Shafi Shahid , Schuster Kevin , Becher Robert , Davis Kimberly A. , Haider Adil H.
Published: July 2017

Objectives:

To determine whether racial/ethnic disparities in 30/90/180-day mortality, major morbidity, and unplanned readmissions exist among universally insured older adult (≥65 years) emergency general surgery patients; vary by diagnostic category; and can be explained by variations in geography, teaching status, age-cohort, and a hospital's percentage of minority patients.

Summary of Background Data:

As the US population ages and discussions surrounding the optimal method of insurance provision increasingly enter into national debate, longer-term outcomes are of paramount concern. It remains unclear the extent to which insurance changes disparities throughout patients’ postacute recovery period among older adults.

Methods:

Survival analysis of 2008 to 2014 Medicare data using risk-adjusted Cox proportional-hazards models.

Results:

A total of 6,779,649 older adults were included, of whom 82.8% identified as non-Hispanic white (NHW), 9.2% non-Hispanic black (NHB), 5.6% Hispanic, and 1.5% non-Hispanic Asian (NHA). Relative to NHW patients, each group of minority patients was significantly less likely to die [30-day NHB vs NHW hazard ratio (95% confidence interval): 0.88 (0.86–0.89)]. Differences became less apparent as outcomes approached 180 days [180-day NHB vs NHW: 1.00 (0.98–1.02)]. For major morbidity and unplanned readmission, differences among NHW, Hispanic, and NHA patients were comparable. NHB patients did consistently worse. Efforts to explain the occurrence found similar trends across diagnostic categories, but significant differences in disparities attributable to geography and the other included factors that combined accounted for up to 50% of readmission differences between racial/ethnic groups.

Conclusion:

The study found an inversion of racial/ethnic mortality differences and mitigation of non-NHB morbidity/readmission differences among universally insured older adults that decreased with time. Persistent disparities among nonagenarian patients and hospitals managing a regionally large share of minority patients warrant particular concern.
Percutaneous Electrical Neurostimulation of Dermatome T6 for Short-term Weight Loss in Overweight and Obese Patients: Effect on Ghrelin Levels, Glucose, Lipid, and Hormonal Profile
Authors: Ruiz-Tovar Jaime , Llavero Carolina , Smith Walter
Published: July 2017

Background:

Percutaneous electrical neurostimulation of dermatome T6 (PENS T6), associated with a low-caloric diet, has previously demonstrated to achieve a reduction in the appetite perception, inducing a better compliance of the prescribed diet and finally leading to a greater weight loss. Ghrelin has been hypothesized to be implicated in the effect of PENS T6. The aim of this study was to evaluate the effect of PENS T6 with hypocaloric diet on appetite, weight loss and dietary compliance, and its association with plasma ghrelin levels, in comparison with PENS T6 associated with normocaloric diet, transcutaneous electrical neurostimulation of T11-T12 (placebo) with hypocaloric diet, and only hypocaloric diet.

Patients and Methods:

A prospective, randomized study was performed. Patients with body mass index >25 kg/m2 were included. The subjects were randomized into 4 groups: patients undergoing PENS T6 in conjunction with a 1200 kcal/d diet (group 1). Patients undergoing PENS T6 and following a normocaloric diet (group 2), patients undergoing transcutaneous electrical neurostimulation of dermatomes in right iliac fossa (T11-T12) and following a 1200 kcal/d diet(group 3) and those patients following only a 1200 kcal/d diet (group 4).

Results:

A total of 200 patients were included, 50 in each group. A significantly greater weight loss was obtained in patients following PENS T6 combined with diet, when compared with the other groups. Patients undergoing PENS T6, associated or not to hypocaloric diet, experienced appetite reduction and lower ghrelin levels, when compared with the other groups.

Conclusions:

The greater weight loss experienced in the patients undergoing PENS T6 is associated with appetite reduction and greater diet compliance. Appetite reduction is associated with ghrelin decrease.
Hydrogen activation using a novel tribenzyltin Lewis acid
Authors: Cooper Robert T. , Sapsford Joshua S. , Turnell-Ritson Roland C. , Hyon Dong-Hun , White Andrew J. P. , Ashley Andrew E.
Published: July 2017

Over the last decade there has been an explosion in the reactivity and applications of frustrated Lewis pair (FLP) chemistry. Despite this, the Lewis acids (LAs) in these transformations are often boranes, with heavier
p
-block elements receiving surprisingly little attention. The novel LA Bn
3
SnOTf (
1
) has been synthesized from simple, inexpensive starting materials and has been spectroscopically and structurally characterized. Subtle modulation of the electronics at the tin centre has led to an increase in its Lewis acidity in comparison with previously reported R
3
SnOTf LAs, and has facilitated low temperature hydrogen activation and imine hydrogenation. Deactivation pathways of the R
3
Sn
+
LA core have also been investigated.

This article is part of the themed issue ‘Frustrated Lewis pair chemistry’.
Reactions of biologically inspired hydride sources with B(C
6
F
5
)
3
Authors: Wilkins Lewis C. , Santi Nicolò , Luk Louis Y. P. , Melen Rebecca L.
Published: July 2017

The combination of 1-benzyl-1,4-dihydropyridines with the strong Lewis acid, B(C
6
F
5
)
3
, generates a stable pyridinium borohydride species in high yields (94%) in as little as 10 min. This use of biologically inspired hydride sources further builds on the recent work of new hydride donors in the formation of borohydrides. When functionalizing the dihydropyridine with an amide or carboxylic acid moiety, a disproportionation reaction composed of a series of protonation/reduction steps is observed upon the addition of B(C
6
F
5
)
3
. As a result, one equivalent of dihydropyridine undergoes net hydrogenation, whereas the other is dehydrogenated yielding the pyridinium counterpart in a transfer hydrogenation-type mechanism.

This article is part of the themed issue ‘Frustrated Lewis pair chemistry’.
Structure and reactivity of an Al/P-based frustrated Lewis pair bearing relatively small substituents at aluminium
Authors: Pleschka Damian , Layh Marcus , Rogel Friedhelm , Uhl Werner
Published: July 2017

Reaction of Mes
2
P─C≡C─Ph (Mes = mesityl) with dineopentylaluminium hydride afforded by hydroalumination a geminal Al/P-based frustrated Lewis pair (FLP;
4
). Its steric shielding is relatively low, and its reactivity in various secondary reactions is less hindered by steric repulsion than observed for related compounds having bulkier groups attached to aluminium. FLP
4
yielded adducts with Me
3
C─NCO or benzaldehyde via the formation of Al–O and P–C bonds. Trimethylsilyl azide reacted with
4
under surprisingly mild conditions to afford a nitrene complex by spontaneous N
2
elimination below room temperature. A carbodiimide molecule was coordinated via one of the C=N bonds to form a five-membered AlCPNC heterocycle with an intact C=N bond in an exocyclic position. A very large molecule was obtained by the reaction of two equivalents of
4
with a bifunctional methylene-bridged phenylene isocyanate precursor.

This article is part of the themed issue ‘Frustrated Lewis pair chemistry’.
Schizophrenia Exhibits Bi-Directional Brain-Wide Alterations in Cortico-Striato-Cerebellar Circuits
Authors: Ji Jie Lisa , Diehl Caroline , Schleifer Charles , Tamminga Carol A. , Keshavan Matcheri S. , Sweeney John A. , Clementz Brett A. , Hill S. Kristian , Pearlson Godfrey , Yang Genevieve , Creatura Gina , Krystal John H. , Repovs Grega , Murray John , Winkler Anderson , Anticevic Alan
Published: July 2017

Distributed neural dysconnectivity is considered a hallmark feature of schizophrenia, yet a tension exists between studies pinpointing focal disruptions versus those implicating brain-wide disturbances. The cerebellum and the striatum communicate reciprocally with the thalamus and cortex through monosynaptic and polysynaptic connections, forming cortico-striatal-thalamic-cerebellar (CSTC) functional pathways that may be sensitive to brain-wide dysconnectivity in schizophrenia. It remains unknown if the same pattern of alterations persists across CSTC systems, or if specific alterations exist along key functional elements of these networks. We characterized connectivity along major functional CSTC subdivisions using resting-state functional magnetic resonance imaging in 159 chronic patients and 162 matched controls. Associative CSTC subdivisions revealed consistent brain-wide bi-directional alterations in patients, marked by hyper-connectivity with sensory-motor cortices and hypo-connectivity with association cortex. Focusing on the cerebellar and striatal components, we validate the effects using data-drivenk-means clustering of voxel-wise dysconnectivity and support vector machine classifiers. We replicate these results in an independent sample of 202 controls and 145 patients, additionally demonstrating that these neural effects relate to cognitive performance across subjects. Taken together, these results from complementary approaches implicate a consistent motif of brain-wide alterations in CSTC systems in schizophrenia, calling into question accounts of exclusively focal functional disturbances.
Conditionally Redundant Bacteriocin Targeting byPseudomonas syringae
Authors: Hockett Kevin L. , Clark Meara , Scott Stacey , Baltrus David A.
Published: July 2017

The widespread use of antimicrobials under clinical and agricultural settings has resulted in the evolution of resistance to these compounds. To combat the emergence of resistance, current research efforts are focusing on designing treatments to exploit combinations of antimicrobials, where the evolution of resistance confers sensitivity to alternative compounds. In this work we demonstrate that strains ofPseudomonas syringaepossess a natural analogue to this strategy. Specifically, we demonstrate that a single strain produces multiple bacteriocins that can target another strain, but antimicrobial activity of the second bacteriocin is manifest only after resistance to the first emerges. The evolution of resistance also sensitizes the target strain to bacteriocins from a variety of other strains. Strains ofP. syringaetherefore encode multiple bacteriocins that can act in a conditionally redundant manner. It is possible that combinations of bacteriocins could be applied as a cocktail or sequentially, to potentially achieve durable pathogen control.
Termite communities along a disturbance gradient in a West African savanna
Authors: Schyra Janine , Korb Judith
Published: July 2017

Termites are important ecosystem engineers, crucial for the maintenance of tropical biodiversity and ecosystem functioning. But they are also pests which cause billions of dollars in damage annually to humans. Currently, our understanding of the mechanisms influencing species occurrences is limited and we do not know what distinguishes pest from non-pest species. We analyzed how anthropogenic disturbance (agriculture) affects species occurrences. We tested the hypothesis that strong disturbance functions as a habitat filter and selects for a subset of species which are major pests of crop. Using a cross-sectional approach, we studied termite community composition along a disturbance gradient from fields to 12-year-old fallows in a West African savanna. We reliably identified 19 species using genetic markers with a mean of about 10 species - many of them from the same feeding type - co-occurring locally. Supporting our hypothesis, disturbance was associated with environmental filtering of termites from the regional species pool, maybe via its effect on vegetation type. The most heavily disturbed sites were characterized by a subset of termite species which are well-known pests of crop. This is in line with the idea that strong anthropogenic disturbance selects for termite pest species.
The human auditory brainstem response to running speech reveals a subcortical mechanism for selective attention
Authors: Forte Antonio Elia , Etard Octave , Reichenbach Tobias
Published: July 2017

Humans excel at selectively listening to a target speaker in background noise such as competing voices. While the encoding of speech in the auditory cortex is modulated by selective attention, it remains debated whether such modulation occurs already in subcortical auditory structures. Investigating the contribution of the human brainstem to attention has, in particular, been hindered by the tiny amplitude of the brainstem response. Its measurement normally requires a large number of repetitions of the same short sound stimuli, which may lead to a loss of attention and to neural adaptation. Here we develop a mathematical method to measure the auditory brainstem response to running speech, an acoustic stimulus that does not repeat and that has a high ecological validity. We employ this method to assess the brainstem’s activity when a subject listens to one of two competing speakers, and show that the brainstem response is consistently modulated by attention.
Temperature selection drives evolution of function-valued traits in a marine diatom
Authors: O’Donnell Daniel R. , Hamman Carolyn R. , Johnson Evan C. , Klausmeier Christopher A. , Litchman Elena
Published: July 2017

Rapid evolution in response to environmental change will likely be a driving force determining the distribution of species and the structure of communities across the biosphere in coming decades. This is especially true of microorganisms, many of which may be able to evolve in step with rising temperatures. An ecologically indispensable group of microorganisms with great potential for rapid thermal adaptation are the phytoplankton, the diverse photosynthetic microbes forming the foundation of most aquatic food webs. We tested the capacity of a globally important phytoplankton species, the marine diatomThalassiosira pseudonana, for rapid evolution in response to temperature. Evolution of replicate populations at 16 and 31°C for 350-450 generations led to significant divergence in several traits associated withT. pseudonana’s thermal reaction norm (TRN) for per-capita population growth, as well as in its competitive ability for nitrogen (commonly limiting in marine systems). Of particular interest were evolution of the optimum temperature for growth, the upper critical temperature, and the derivative of the TRN, an indicator of potential tradeoffs resulting from local adaptation to temperature. This study offers a broad examination of the evolution of the thermal reaction norm and how modes of TRN variation may govern a population’s long-term physiological, ecological, and biogeographic response to global climate change.
High-depth whole genome sequencing of a large population-specific reference panel: Enhancing sensitivity, accuracy, and imputation
Authors: Lencz Todd , Yu Jin , Palmer Cameron , Carmi Shai , Ben-Avraham Danny , Barzilai Nir , Bressman Susan , Darvasi Ariel , Cho Judy H. , Clark Lorraine N. , Gümüş Zeynep H. , Joseph Vijai , Klein Robert , Lipkin Steven , Offit Kenneth , Ostrer Harry , Ozelius Laurie J. , Peter Inga , Atzmon Gil , Pe’er Itsik
Published: July 2017

Background

While increasingly large reference panels for genome-wide imputation have been recently made available, the degree to which imputation accuracy can be enhanced by population-specific reference panels remains an open question. In the present study, we sequenced at full-depth (≥30x) a moderately large (n=738) cohort of samples drawn from the Ashkenazi Jewish population across two platforms (Illumina X Ten and Complete Genomics, Inc.). We developed and refined a series of quality control steps to optimize sensitivity, specificity, and comprehensiveness of variant calls in the reference panel, and then tested the accuracy of imputation against target cohorts drawn from the same population.

Results

For samples sequenced on the Illumina X Ten platform, quality thresholds were identified that permitted highly accurate calling of single nucleotide variants across 94% of the genome. The Complete Genomics, Inc. platform was more conservative (fewer variants called) compared to the Illumina platform, but also demonstrated relatively greater numbers of false positives that needed to be filtered. Quality control procedures also permitted detection of novel genome reads that are not mapped to current reference or alternate assemblies. After stringent quality control, the population-specific reference panel produced more accurate and comprehensive imputation results relative to publicly available, large cosmopolitan reference panels. The population-specific reference panel also permitted enhanced filtering of clinically irrelevant variants from personal genomes.

Conclusions

Our primary results demonstrate enhanced accuracy of a population-specific imputation panel relative to cosmopolitan panels, especially in the range of infrequent (<5% non-reference allele frequency) and rare (<1% non-reference allele frequency) variants that may be most critical to further progress in mapping of complex phenotypes.
Activated CD8 T cells express two distinct P-Selectin Ligands
Authors: Carlow Douglas A. , Tra Michelle C. , Ziltener Hermann J.
Published: July 2017

One sentence summary

Murine primary in-vivo activated CD8+ T cells express two ligands for P-selectin, canonical PSGL-1 and a cell-extrinsic ligand docked on L-selectin.

P-selectin (PSel) expressed on activated endothelia and platelets supports recruitment of leukocytes expressing PSel ligand (PSelL) to sites of inflammation. While monitoring PSelL expression on activated CD8+T cells (Tact) in adoptive transfer models, we observed two distinct PSelL on responding donor cells, the canonical cell-intrinsic PSelL PSGL1 and a second undocumented PSelL provisionally named PSL2. PSL2 is unusual among selectin ligands in that it is cell-extrinsic, loaded onto L-selectin (LSel) expressed by Tact but not LSel on resting naïve CD8+T cells. PSL2 expression is highest on Tact responding in peripheral lymph nodes and low on Tact responding in spleen suggesting that the original source of PSL2 is high endothelial venules, cells known to produce LSelL. When both PSGL1 and PSL2 were absent from the surface of Tact, no significant residual PSelL activity was detected. PSL2 is a ligand for both PSel and LSel and can physically bridge the two selectins. The LSel/PSL2 complex can mediate PSel-dependent adherence of Tact to immobilized PSel-hIgG or to activated platelets, either independently or cooperatively with PSGL1. PSel engagement of PSGL1 and LSel/PSL2 would likely deliver distinct signals known to be relevant in leukocyte recruitment.
(Pyridin-2-yl)methyl 2-oxo-1-[(pyridin-2-yl)methyl]-1,2-dihydroquinoline-4-carboxylate hemihydrate
Authors: Filali Baba Yassir , Kandri Rodi Youssef , Ouzidan Younes , Mague Joel T. , Ouazzani Chahdi Fouad , Essassi El Mokhtar
Published: July 2017

In the title compound, C22H17N3O3·0.5H2O, the heterocyclic portion of the dihydroquinoline moiety is distinctly nonplanar. Two quinolinecarboxylate molecules are associated through hydrogen bonding to a disordered lattice water molecule. These units stack along the a-axis direction assisted by C—H...O and C—H...N hydrogen bonds, as well as C—H...π(ring) interactions.
(E)-2-Phenyl-4-styryl-2,3-dihydro-1H-1,5-benzodiazepine hemihydrate
Authors: Loughzail Mohamed , Adardour Mohamed , Dahaoui Slimane , Baouid Abdesselam
Published: July 2017

The unit cell contains eight molecules of the title compound, with half a water molecule per main molecule, C23H20N2·0.5H2O. The seven-membered diazepine ring adopts a twist-boat conformation and makes dihedral angles of 85.08 (7) and 32.79 (7)° with the phenyl and styryl substituents, respectively. In the crystal, the organic molecules are linked by C—H...N hydrogen bonds into chains running along the b-axis direction. The water molecule, located on a twofold rotation axis, forms hydrogen bridges, connecting two adjacent chains.
An analysis of the Gezi Park social movement tweets
Authors: Ozturkcan Selcen , Kasap Nihat , Cevik Muge , Zaman Tauhid
Published: July 2017

Purpose

Twitter usage during Gezi Park Protests, a significant large-scale connective action, is analyzed to reveal meaningful findings on individual and group tweeting characteristics. Subsequent to the Arab Spring in terms of its timing, the Gezi Park Protests began by the spread of news on construction plans to build a shopping mall at a public park in Taksim Square in Istanbul on May 26, 2013. Though started as a small-scale local protest, it emerged into a series of multi-regional social protests, also known as the Gezi Park demonstrations. The paper aims to discuss these issues.

Design/methodology/approach

The authors sought answers to three important research questions: whether Twitter usage is reflective of real life events, what Twitter is actually used for, and is Twitter usage contagious? The authors have collected streamed data from Twitter. As a research methodology, the authors followed social media analytics framework proposed by Fan and Gordon (2014), which included three consecutive processes; capturing, understanding, and presenting. An analysis of 54 million publicly available tweets and 3.5 million foursquare check-ins, which account to randomly selected 1 percent of all tweets and check-ins posted from Istanbul, Turkey between March and September 2013 are presented.

Findings

A perceived lack of sufficient media coverage on events taking place on the streets is believed to result in Turkish protestors’ use of Twitter as a medium to share and get information on ongoing and planned demonstrations, to learn the recent news, to participate in the debate, and to create local and global awareness.

Research limitations/implications

Data collection via streamed tweets comes with certain limitations. Twitter restricts data collection on publicly available tweets and only allows randomly selected 1 percent of all tweets posted from a specific region. Therefore, the authors’ data include only tweets of publicly available Twitter profiles. The generalizability of the findings should be regarded with concerning this limitation.

Practical implications

The authors conclude that Twitter was used mainly as a platform to exchange information to organize street demonstrations.

Originality/value

The authors conclude that Twitter usage reflected Street movements on a chronological level. Finally, the authors present that Twitter usage is contagious whereas tweeting is not necessarily.
The effects of internet filtering on users’ information-seeking behaviour and emotions
Authors: Jamali Hamid R. , Shahbaztabar Pria
Published: July 2017

Purpose

The purpose of this paper is to investigate the relationship between internet filtering, emotions and information-seeking behaviour.

Design/methodology/approach

In total, 15 postgraduate students at an Iranian university participated in the study which involved a questionnaire, search tasks with think aloud narratives, and interviews.

Findings

Internet content filtering results in some changes in the information-seeking behaviour of users. Users who face website blocking use a variety of methods to bypass filtering, mostly by using anti-filter software. Filtering encourages users to use channels such as social networking services to share resources and it increases the use of library material by some of the users. Users who face filtering during their search are more likely to visit more pages of results and click on more hits in the results, unlike users who do not experience filtering who rarely go past the first page. Blocking users’ access to content stimulates their curiosity and they become more determined to access the content. In terms of the affective aspect, filtering causes several negative emotions (e.g. anger, disgust, sadness and anxiety) and the main reason for these emotions is not the inability to access information but the feeling of being controlled and not having freedom.

Research limitations/implications

The study was limited to a small number of postgraduate students in social sciences and not generalisable to all user groups. The implication is that in countries where filtering is used, libraries can play an important role in serving users and reducing users negative emotions, especially if libraries can take advantage of technologies such as social media for their services.

Originality/value

This is first study to address the effects of internet filtering on information-seeking behaviour and emotions. The study shows that internet filtering causes negative emotions and results in some changes in information-seeking behaviour.
A teaching note on the controllability “Principle” and performance measurement
Authors: Schwartz Steven T. , Spires Eric E. , Young Richard A.
Published: July 2017

Purpose

The purpose of this note is to expose accounting students and others to recent findings in management control, specifically to the relationship between the informativeness of a performance measure and its usefulness in performance evaluation.

Design/methodology/approach

Numerical examples illuminate key ideas and are easy to follow and replicate by students.

Findings

Seemingly in contradiction to the controllability principle, performance measures that are informative about actions taken by employees are not necessarily useful for performance evaluation. This occurs when the performance being measured is related to an intermediate task, such as prepping items prior to final assembly. If prepping is an important factor in the quality of not only the intermediate good but also the finished good, and the quality of the finished good can be reasonably measured, it may not be useful to measure the prepping performance. This result holds even if obtaining the intermediate measure is costless and the intermediate measure provides unique information on the effort given to the intermediate task.

Originality/value

Opportunities to measure employees’ intermediate outputs are ubiquitous; therefore, judicious decisions should be made regarding the use of limited monitoring resources. This note contains intuitive, easy-to-follow illustrations (based on recent findings) that will help students and others identify situations where such evaluations are more and less useful.