bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes to the Composition of the Gastrointestinal Microbiome after Probiotics for Clostridium difficile Infection in Adults
Authors: Eggers Shoshannah , De Wolfe Travis , Barker Anna , Duster Megan , Dill-McFarland Kimberly , Suen Garret , Safdar Nasia
Published: October 2017

Background

Clostridium difficile infections (CDI) in the US have markedly increased. Disturbances to the gastrointestinal (GI) microbiome due to antibiotic use predisposes patients to CDI. Probiotics are recommended to prevent GI microbiota changes during CDI antibiotic treatment, but efficacy is unknown. We conducted a randomized, double-blinded, placebo-controlled, examination of clinical and GI microbiota changes in subjects administered probiotics during a primary episode of CDI.

Methods

33 subjects with a primary episode of CDI were randomized to once daily oral probiotic, consisting of four different bacterial strains, or placebo for 4-weeks (week 0–4) concurrent to antibiotic treatment. Subjects completed a daily stool diary, and stool samples were collected at enrollment (week 0), at the end of the probiotic or placebo adjunct regimen (week 4), and 4 weeks post-treatment (week 8). DNA was extracted for 16S rRNA sequencing with Illumina MiSeq. Microbial diversity, richness, and community structure were compared using analysis of variance and permutational analysis of variance. Similarity percentage analysis identified the operational taxonomic units driving the variation in β diversity.

Results

The duration of diarrhea (P = 0.039) and total days of diarrhea (P = 0.005) both decreased in the probiotic group compared with the placebo group. Analysis of community structure showed significant differences between treatment groups overall (P = 0.017) and in both groups over time (P = 0.007), but not between groups at each individual time point. Subjects in the probiotic group had a higher abundance of the family Lachnospiraceae at week 4 than subjects in the placebo group. By week 8 the abundance of Lachnospiraceae did not differ between subjects administered probiotic or placebo.

Conclusion

Lack of difference in overall community structure between groups at each time point is likely due to concurrent antibiotic therapy. The differential abundance of Lachnospiraceae likely contributes to the differences in the diarrheal outcomes observed between groups, as it has previously been associated with attenuated C. difficile pathology. Shortening the duration of diarrhea from an initial CDI may reduce the spread of C. difficile and improve clinical outcomes.

Disclosures

All authors: No reported disclosures.
Incidence of Pediatric Community Associated Clostridium Difficile Infection Following Common Antibotics
Authors: Katz Margot Miranda , Parmar Deepika , Dang Rebecca , Alabaster Amy , Greenhow Tara
Published: October 2017

Background

As rates of pediatric community-associated (CA) Clostridium difficile infection (CDI) increase, additional research is needed to address rates of infection following common antibiotics.

Methods

This study was a retrospective review of the electronic health records of all children with stool specimens sent for C difficile from January first 2012 – December 31st2016 at Kaiser Permanente Northern California. Children with clinical symptoms consistent with CDI, confirmatory laboratory testing, no other identified causes of diarrhea, and community associated disease were defined as cases. Using outpatient and ED antibiotic prescription records for children, incidence rates were calculated for subsequent CA CDI for the most commonly prescribed antibiotics.

Results

Of 507 primary CDI cases in our cohort, 327 had any antibiotic use 2012–2015. There were 205 primary CDI cases that were preceded by an antibiotic in the previous 1–365 days. Many of these patients had more than 1 antibiotic in the preceding year.

Of those, rates of CA CDI were uncommon following common antibiotics. (Table) The highest rate of CA CDI followed ceftriaxone, cefdinir, ciprofloxacin and augmentin. The lowest rates were seen following penicillin, doxycycline and azithromycin. Ninety-three percent of the antibiotic prescriptions were in outpatients, 7% in inpatients.

Conclusion

As rates of CA CDI increase, clinicians should be aware of rates of infection following administration of common antibiotics. The most common antibiotics to cause CA CDI were third-generation cephalosporins (ceftriaxone and cefdinir) and ciprofloxacin.

Disclosures

All authors: No reported disclosures.
PCR Cycle-Threshold-Derived Toxin Identifies Patients at Low-Risk for Complications of C. difficile Infection Who Do Not Require Treatment
Authors: Hitchcock Matthew , Holubar Marisa , Tompkins Lucy , Banaei Niaz
Published: October 2017

Background

Literature suggests that toxin detection differentiates those who require treatment for C. difficile infection (CDI) from those who do not. In-house studies have shown that free toxin can be predicted with high negative predictive value at a predefined cycle threshold (CT) using Xpert tcdB PCR (Cepheid, Sunnyvale, CA). In October 2016, CT-toxin was added to the PCR result and a comment recommends against CDI therapy if CT-toxin is negative (CTtox-). Here we evaluate the effect of this reporting on treatment rates and outcomes of CTtox- patients.

Methods

Patients tested from October 2016 to Apr. 2017 with a positive Xpert PCR and CTtox- result were included. Clinical data were collected by retrospective chart review and analyzed with the Chi squared and Student t-tests using SPSS. Due to multiple comparisons, α=0.01.

Results

Of 1516 Xpert PCR tests, 248 (16.4%) were positive and 98 (39.5%) were CTtox-. Of these, 54 (55.7%) were treated. Patient characteristics and data at testing are shown below. There were no cases of CDI-related septic shock or toxic megacolon on review. Time to diarrhea resolution was significantly shorter in untreated patients and there was no difference in crude mortality or later onset of CTtox+ CDI.

Conclusion

This study demonstrates the impact of stand-alone PCR assay with toxin prediction on reducing CDI therapy rates and provides further evidence that PCR+/toxin- patients are at low risk for CDI-related complications and do not require treatment, though more data is needed in transplant populations.

Disclosures

N. Banaei, Cepheid: Collaborator, Research Contractor and Scientific Advisor, honorarium for advisory role and Research support
Possible Impact of Wide-scale Vaccination Against Serogroup B Neisseria Meningitidis on Gonorrhea Incidence Rates in One Region of Quebec, Canada
Authors: Longtin Jean , Dion Rejean , Simard Marc , Betala Belinga Jean-Francois , Longtin Yves , Lefebvre Brigitte , Labbé Annie-Claude , Deceuninck Genevieve , De Wals Philippe
Published: October 2017

Background

Owing to a persistent increase of serogroup B Neisseria meningitidis (Nm) invasive infections in the Saguenay-Lac-Saint-Jean (SLSJ) region of the province of Quebec (Canada) since 2006, a wide-scale vaccination campaign of individuals aged 6 months to 20 years was conducted between May and December 2014 using the 4-component protein-based meningococcus serogroup B vaccine (4CMenB). Components of this vaccine have shown to potentially cross-react with Neisseria gonorrhoeae (Ng). The study objective was to assess the impact of the vaccination campaign on Ng incidence rate (IR).

Methods

Ng cases notified to public health authorities during prevaccination period (January 2006 to June 2014) and postvaccination period (July 2014 to June 2017) were analyzed. The impact of this mass campaign was estimated by a Poisson regression model, including the year (11 July–June categories), age (14–20 vs. 21 years and older), and the intervention (0 by default and 1 in those 14–20 years in the period of July 2014 to June 2017).

Results

Overall vaccine coverage was 82% in the target group. A total of 231 Ng cases were reported among persons 14 years and older (IR: 8.4/100,000 person-years) of the SLSJ region from January 2006 to June 2017. A decrease in the Ng number of cases and IR among individuals 14–20 years was observed during the post-vaccination period whereas it increased in those 21 years and older (figure). Estimate of vaccination impact was an Ng risk reduction of 59% (95% CI: −22% to 84%; P = 0.1). During the same period, Chlamydia trachomatis (Ct) infections increased among persons of both age groups in the SLSJ region.

Conclusion

Although the estimate of the impact of the campaign was not statistically significant, possibly due to limited size of the study population and the low incidence of the disease, it is congruent with results of a case–control study in New Zealand showing an OMV-MeNZB vaccine effectiveness of 31%. A higher effectiveness of 4CMenB is a plausible hypothesis as three additional proteins also found in Ng are included in the vaccine used in the SLSJ region. The results of this ecologic study suggest cross-protection of 4CMenB vaccine against Ng infections. Further studies on this topic are warranted.

Disclosures

P. De Wals, GlaxoSmithKline: Grant Investigator and Scientific Advisor, Grant recipient and travel expenses. Pfizer: Grant Investigator and Scientific Advisor, Grant recipient and travel expenses. Sanofi-Pasteur: Grant Investigator and Scientific Advisor, Grant recipient and travel expenses. Novartis: Grant Investigator and Scientific Advisor, Grant recipient and travel expenses.
Kilonova from post-merger ejecta as an optical and near-Infrared counterpart of GW170817
Authors: Tanaka Masaomi , Utsumi Yousuke , Mazzali Paolo A. , Tominaga Nozomu , Yoshida Michitoshi , Sekiguchi Yuichiro , Morokuma Tomoki , Motohara Kentaro , Ohta Kouji , Kawabata Koji S. , Abe Fumio , Aoki Kentaro , Asakura Yuichiro , Baar Stefan , Barway Sudhanshu , Bond Ian A. , Doi Mamoru , Fujiyoshi Takuya , Furusawa Hisanori , Honda Satoshi , Itoh Yoichi , Kawabata Miho , Kawai Nobuyuki , Kim Ji Hoon , Lee Chien-Hsiu , Miyazaki Shota , Morihana Kumiko , Nagashima Hiroki , Nagayama Takahiro , Nakaoka Tatsuya , Nakata Fumiaki , Ohsawa Ryou , Ohshima Tomohito , Okita Hirofumi , Saito Tomoki , Sumi Takahiro , Tajitsu Akito , Takahashi Jun , Takayama Masaki , Tamura Yoichi , Tanaka Ichi , Terai Tsuyoshi , Tristram Paul J. , Yasuda Naoki , Zenko Tetsuya
Published: October 2017

Recent detection of gravitational waves from a neutron star (NS) merger event GW170817 and identification of an electromagnetic counterpart provide a unique opportunity to study the physical processes in NS mergers. To derive properties of ejected material from the NS merger, we perform radiative transfer simulations of kilonova, optical and near-infrared emissions powered by radioactive decays of r-process nuclei synthesized in the merger. We find that the observed near-infrared emission lasting for >10 d is explained by 0.03 M⊙ of ejecta containing lanthanide elements. However, the blue optical component observed at the initial phases requires an ejecta component with a relatively high electron fraction (Ye). We show that both optical and near-infrared emissions are simultaneously reproduced by the ejecta with a medium Ye of ∼0.25. We suggest that a dominant component powering the emission is post-merger ejecta, which exhibits that the mass ejection after the first dynamical ejection is quite efficient. Our results indicate that NS mergers synthesize a wide range of r-process elements and strengthen the hypothesis that NS mergers are the origin of r-process elements in the Universe.
Calling to Nursing
Authors: Emerson Christie
Published: October 2017

The aims of this article are (a) to analyze the concept of a calling as it relates nursing and (b) to develop a definition of calling to nursing with the detail and clarity needed to guide reliable and valid research. The classic steps described by Walker and Avant are used for the analysis. Literature from several disciplines is reviewed including vocational psychology, Christian career counseling, sociology, organizational management, and nursing. The analysis provides an operational definition of a calling to nursing and establishes 3 defining attributes of the concept: (a) a passionate intrinsic motivation or desire (perhaps with a religious component), (b) an aspiration to engage in nursing practice, as a means of fulfilling one's purpose in life, and (c) the desire to help others as one's purpose in life. Antecedents to the concept are personal introspection and cognitive awareness. Positive consequences to the concept are improved work meaningfulness, work engagement, career commitment, personal well-being, and satisfaction. Negative consequences of having a calling might include willingness to sacrifice well-being for work and problems with work-life balance. Following the concept analysis, philosophical assumptions, contextual factors, interdisciplinary work, research opportunities, and practice implications are discussed.
Pleuropulmonary Blastoma: A Single-center Case Series of 6 Patients
Authors: Pierce Janie M. , LaCroix Priscilla , Heym Kenneth , Bowman William P. , Margraf Linda , Iglesias Jose , Ray Anish
Published: October 2017

Pleuropulmonary blastoma (PPB) is a rare malignancy of childhood which when left untreated often shows pathologic progression resulting in a more aggressive neoplasm with an increasingly poor prognosis. Because of this it is important to diagnose and initiate treatment early. However, early stage PPB can appear as a cystic lung lesion on imaging and can be easily misdiagnosed given the rarity of the malignancy. Moreover, current therapeutic guidelines for these lesions are not well established, making treatment decisions and management difficult for clinicians. DICER1 mutations are known to be present in a majority of PPBs with or without a germline mutation and may be part of a familial tumor predisposition syndrome. The clinical, pathologic, and genetic data of 6 patients are summarized here. Two patients with type I PPB and 4 patients with type II PPB underwent surgical and chemotherapeutic treatment and all are alive and without recurrence 1 to 13 years after treatment. With increasing awareness of PPB, it is important for clinicians to consider this malignant entity in the evaluation and treatment of patients presenting with a cystic lung abnormality, especially in cases with a history strongly suggestive of a DICER1 mutation.
Autoimmune Lymphoproliferative Syndrome Masquerading as Posttransplant Lymphoproliferative Disorder
Authors: Jeffreys Sarah M. , Levy Rebecca A. , Crary Shelley E.
Published: October 2017

We present a case of a 2-year-old female presenting with diffuse lymphadenopathy 2 years following orthotopic heart transplant. Initially, she was diagnosed with posttransplant lymphoproliferative disease based on clinical presentation and pathology and she was treated accordingly. Because of persistent lymphadenopathy following the completion of chemotherapy and new onset of autoimmune cytopenias, repeat flow of the lymph node showed an elevated double negative T-cell population prompting evaluation for autoimmune lymphoproliferative syndrome (ALPS). A complete workup was confirmative of a germline Fas mutation consistent with ALPS-FAS. This case emphasizes the importance of considering ALPS-FAS in a patient with lymphadenopathy of unknown cause.
A Heterozygous CFHR3-CFHR1 Gene Deletion in a Pediatric Patient With Transplant-associated Thrombotic Microangiopathy Who was Treated With Eculizumab
Authors: Nozawa Akifumi , Ozeki Michio , Hori Tomohiro , Kawamoto Norio , Hirayama Masahiro , Azuma Eiichi , Fukao Toshiyuki
Published: October 2017

Complement system dysregulation, such as complement Factor H (CFH) autoantibodies and deletions in CFH-related (CFHR) genes 3 and 1, might cause transplant-associated thrombotic microangiopathy (TA-TMA). The use of eculizumab, a terminal complement inhibitor, could be a targeted therapy for TA-TMA. We report a 1-year-old girl who developed TA-TMA, just after autologous peripheral blood stem cell transplantation in neuroblastoma therapy. Eculizumab improved TA-TMA. Investigation for the complement alternative pathway showed a heterozygous CFHR3-CFHR1 gene deletion, which is involved in complement activation. The patient might develop TA-TMA as a result of complement regulatory gene mutation.
Prospects for adoptive T-cell therapy for invasive fungal disease
Authors: Castellano-Gonzalez Gloria , Clancy Leighton E. , Gottlieb David
Published: October 2017

Purpose of review

Invasive fungal disease (IFD) is a cause of morbidity and mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. As more potent broad-spectrum antifungal agents are used in prophylaxis, drug resistance and less common fungal species have increased in frequency. Here we review current treatments available for IFD and examine the potential for adoptive T-cell treatment to enhance current therapeutic choices in IFD.

Recent findings

There is growing evidence supporting the role of T cells as well as phagocytes in antifungal immunity. T cells recognizing specific antigens expressed on fungal morphotypes have been identified and the role of T-cell transfer has been explored in animal models. The clinical efficacy of adoptive transfer of antigen-specific T cells for prophylaxis and treatment of viral infections post-HSCT has raised interest in developing good manufacturing practice (GMP)-compliant methods for manufacturing and testing fungus-specific T cells after HSCT.

As the outcomes of IFD post-HSCT are poor, reconstitution of antifungal immunity offers a way to correct the underlying deficiency that has caused the infection rather than simply pharmacologically suppress fungal growth. The clinical development of fungus specific T cells is in its early stages and clinical trials are needed in order to evaluate safety and efficacy.
Advances in the understanding and management of mucositis during stem cell transplantation
Authors: Bowen Joanne M. , Wardill Hannah R.
Published: October 2017

Purpose of review

Mucositis is a severe and common side effect of anticancer treatments, with an incidence of between 40 and 80% depending on the cytotoxic regimen used. The most profound mucositis burden is experienced during conditioning regimens for hematopoietic stem cell transplant (HSCT), where the use of highly mucotoxic agents with or without total body irradiation leads to serious damage throughout the alimentary tract. Currently, the assessment and management of both oral and gastrointestinal mucositis lack authoritative guideline, with recommendations only achieved in narrow clinical scenarios. This review provides a brief overview of current management guidelines for mucositis in both adult and pediatric patients receiving HSCT, highlights recent advances in mucositis prevention and discusses future research avenues.

Recent findings

The Multinational Association of Supportive Care in Cancer and International Society for Oral Oncology (MASCC/ISOO) guidelines for the prevention of mucositis in HSCT are scarce, with low level laser therapy (photobiomodulation) and palifermin only recommended for oral mucositis. Loperamide and octreotide remain gold-standard for the treatment of diarrhea, despite poor efficacy. Although several interventions have been trialled in pediatric cohorts, no recommendations currently exist for children receiving high-dose chemotherapy or total body irradiation for HSCT.

HSCT continues to be associated with mucositis, which impacts on patients’ ability and willingness to receive engraftment, and worsens clinical outcome. Research into the prevention and treatment of mucositis in this setting remains limited, with an overwhelming amount of small, single-center studies that fail to achieve a sufficient level of evidence that warrant recommendation(s). As such, our ability to manage mucotoxic side effects of high-dose chemotherapy and irradiation is limited, particularly in children.
The effects of cryopreserved red blood cell transfusion on tissue oxygenation in obese trauma patients
Authors: McCully Belinda H. , Underwood Samantha J. , Kiraly Laszlo , Holcomb John B. , Robinson Bryce R.H. , Minei Joseph P. , Stewart Ronald M. , Cotton Bryan A. , Gordon Nicole T. , Martin David T. , Rick Elizabeth A. , Dean Rondi K. , Wiles Connor , Anderson Nathan , Schreiber Martin A.
Published: October 2017

BACKGROUND

Low tissue oxygenation (StO2) is associated with poor outcomes in obese trauma patients. A novel treatment could be the transfusion of cryopreserved packed red blood cells (CPRBCs), which the in vitro biochemical profile favors red blood cell (RBC) function. We hypothesized that CPRBC transfusion improves StO2 in obese trauma patients.

METHODS

Two hundred forty-three trauma patients at five Level I trauma centers who required RBC transfusion were randomized to receive one to two units of liquid packed RBCs (LPRBCs) or CPRBCs. Demographics, injury severity, StO2, outcomes, and biomarkers of RBC function were compared in nonobese (body mass index [BMI] < 30) and obese (BMI ≥ 30) patients. StO2 was also compared between obese patients with BMI of 30 to 34.9 and BMI ≥ 35. StO2 was normalized and expressed as % change after RBC transfusion. A p value less than 0.05 indicated significance.

RESULTS

Patients with BMI less than 30 (n = 141) and BMI of 30 or greater (n = 102) had similar Injury Severity Score, Glasgow Coma Scale, and baseline StO2. Plasma levels of free hemoglobin, an index of RBC lysis, were lower in obese patients after CPRBC (125 [72–259] μg/mL) versus LPRBC transfusion (230 [178–388] μg/mL; p < 0.05). StO2 was similar in nonobese patients regardless of transfusion type, but improved in obese patients who received CPRBCs (104 ± 1%) versus LPRPCs (99 ± 1%, p < 0.05; 8 hours after transfusion). Subanalysis showed improved StO2 after CPRBC transfusion was specific to BMI of 35 or greater, starting 5 hours after transfusion (p < 0.05 vs. LPRBCs). CPRBCs did not improve clinical outcomes in either group.

CONCLUSION

CPRBC transfusion is associated with increased StO2 and lower free hemoglobin levels in obese trauma patients, but did not improve clinical outcomes. Future studies are needed to determine if CPRBC transfusion in obese patients attenuates hemolysis to improve StO2.

LEVEL OF EVIDENCE

Therapeutic, level IV.
Extended lubrication theory: improved estimates of flow in channels with variable geometry
Authors: Tavakol Behrouz , Froehlicher Guillaume , Holmes Douglas P. , Stone Howard A.
Published: October 2017

Lubrication theory is broadly applicable to the flow characterization of thin fluid films and the motion of particles near surfaces. We offer an extension to lubrication theory by starting with Stokes equations and considering higher-order terms in a systematic perturbation expansion to describe the fluid flow in a channel with features of a modest aspect ratio. Experimental results qualitatively confirm the higher-order analytical solutions, while numerical results are in very good agreement with the higher-order analytical results. We show that the extended lubrication theory is a robust tool for an accurate estimate of pressure drop in channels with shape changes on the order of the channel height, accounting for both smooth and sharp changes in geometry.
Kinematic dynamos in spheroidal geometries
Authors: Ivers D. J.
Published: October 2017

The kinematic dynamo problem is solved numerically for a spheroidal conducting fluid of possibly large aspect ratio with an insulating exterior. The solution method uses solenoidal representations of the magnetic field and the velocity by spheroidal toroidal and poloidal fields in a non-orthogonal coordinate system. Scaling of coordinates and fields to a spherical geometry leads to a modified form of the kinematic dynamo problem with a geometric anisotropic diffusion and an anisotropic current-free condition in the exterior, which is solved explicitly. The scaling allows the use of well-developed spherical harmonic techniques in angle. Dynamo solutions are found for three axisymmetric flows in oblate spheroids with semi-axis ratios 1≤
a
/
c
≤25. For larger aspect ratios strong magnetic fields may occur in any region of the spheroid, depending on the flow, but the external fields for all three flows are weak and concentrated near the axis or periphery of the spheroid.
Personality-matching habitat choice, rather than behavioural plasticity, is a likely driver of a phenotype–environment covariance
Authors: Holtmann Benedikt , Santos Eduardo S. A. , Lara Carlos E. , Nakagawa Shinichi
Published: October 2017

An emerging hypothesis of animal personality posits that animals choose the habitat that best fits their personality, and that the match between habitat and personality can facilitate population differentiation, and eventually speciation. However, behavioural plasticity and the adjustment of behaviours to new environments have been a classical explanation for such matching patterns. Using a population of dunnocks (Prunella modularis), we empirically tested whether personality or behavioural plasticity is responsible for the non-random distribution of shy and bold individuals in a heterogeneous environment. We found evidence for bold individuals settling in areas with high human disturbance, but also that birds became bolder with increasing age. Importantly, personality primarily determines the distribution of individuals, and behavioural adjustment over time contributes very little to the observed patterns. We cannot, however, exclude a possibility of very early behavioural plasticity (a type of developmental plasticity) shaping what we refer to as ‘personality’. Nonetheless, our findings highlight the role personality plays in shaping population structure, lending support to the theory of personality-mediated speciation. Moreover, personality-matching habitat choice has important implications for population management and conservation.
A possible structural correlate of learning performance on a colour discrimination task in the brain of the bumblebee
Authors: Li Li , MaBouDi HaDi , Egertová Michaela , Elphick Maurice R. , Chittka Lars , Perry Clint J.
Published: October 2017

Synaptic plasticity is considered to be a basis for learning and memory. However, the relationship between synaptic arrangements and individual differences in learning and memory is poorly understood. Here, we explored how the density of microglomeruli (synaptic complexes) within specific regions of the bumblebee (Bombus terrestris) brain relates to both visual learning and inter-individual differences in learning and memory performance on a visual discrimination task. Using whole-brain immunolabelling, we measured the density of microglomeruli in the collar region (visual association areas) of the mushroom bodies of the bumblebee brain. We found that bumblebees which made fewer errors during training in a visual discrimination task had higher microglomerular density. Similarly, bumblebees that had better retention of the learned colour-reward associations two days after training had higher microglomerular density. Further experiments indicated experience-dependent changes in neural circuitry: learning a colour-reward contingency with 10 colours (but not two colours) does result, and exposure to many different colours may result, in changes to microglomerular density in the collar region of the mushroom bodies. These results reveal the varying roles that visual experience, visual learning and foraging activity have on neural structure. Although our study does not provide a causal link between microglomerular density and performance, the observed positive correlations provide new insights for future studies into how neural structure may relate to inter-individual differences in learning and memory.
Fragile coexistence of a global chytrid pathogen with amphibian populations is mediated by environment and demography
Authors: Spitzen-van der Sluijs Annemarieke , Canessa Stefano , Martel An , Pasmans Frank
Published: October 2017

Unravelling the multiple interacting drivers of host–pathogen coexistence is crucial in understanding how an apparently stable state of endemism may shift towards an epidemic and lead to biodiversity loss. Here, we investigate the apparent coexistence of the global amphibian pathogen
Batrachochytrium dendrobatidis
(Bd) with
Bombina variegata
populations in The Netherlands over a 7-year period. We used a multi-season mark–recapture dataset and assessed potential drivers of coexistence (individual condition, environmental mediation and demographic compensation) at the individual and population levels. We show that even in a situation with a clear cost incurred by endemic Bd, population sizes remain largely stable. Current environmental conditions and an over-dispersed pathogen load probably stabilize disease dynamics, but as higher temperatures increase infection probability, changing environmental conditions, for example a climate-change-driven rise in temperature, could unbalance the current fragile host–pathogen equilibrium. Understanding the proximate mechanisms of such environmental mediation and of site-specific differences in infection dynamics can provide vital information for mitigation actions.
Infection rate ofAedes aegyptimosquitoes with dengue virus depends on the interaction between temperature and mosquito genotype
Authors: Gloria-Soria A. , Armstrong P. M. , Powell J. R. , Turner P. E.
Published: October 2017

Dengue fever is the most prevalent arthropod-transmitted viral disease worldwide, with endemic transmission restricted to tropical and subtropical regions of different temperature profiles. Temperature is epidemiologically relevant because it affects dengue infection rates inAedes aegyptimosquitoes, the major vector of the dengue virus (DENV).Aedes aegyptipopulations are also known to vary in competence for different DENV genotypes. We assessed the effects of mosquito and virus genotype on DENV infection in the context of temperature by challengingAe. aegyptifrom two locations in Vietnam, which differ in temperature regimes, with two isolates of DENV-2 collected from the same two localities, followed by incubation at 25, 27 or 32°C for 10 days. Genotyping of the mosquito populations and virus isolates confirmed that each group was genetically distinct. Extrinsic incubation temperature (EIT) and DENV-2 genotype had a direct effect on the infection rate, consistent with previous studies. However, our results show that the EIT impacts the infection rate differently in each mosquito population, indicating a genotype by environment interaction. These results suggest that the magnitude of DENV epidemics may not only depend on the virus and mosquito genotypes present, but also on how they interact with local temperature. This information should be considered when estimating vector competence of local and introduced mosquito populations during disease risk evaluation.
Behavioural mediators of genetic life-history trade-offs: a test of the pace-of-life syndrome hypothesis in field crickets
Authors: Santostefano Francesca , Wilson Alastair J. , Niemelä Petri T. , Dingemanse Niels J.
Published: October 2017

The pace-of-life syndrome (POLS) hypothesis predicts associations between life history and ‘risky’ behaviours. Individuals with ‘fast’ lifestyles should develop faster, reproduce earlier, exhibit more risk-prone behaviours, and die sooner than those with ‘slow’ lifestyles. While support for POLS has been equivocal to date, studies have relied on individual-level (phenotypic) patterns in which genetic trade-offs may be masked by environmental effects on phenotypes. We estimated genetic correlations between life history (development, lifespan, size) and risky behaviours (exploration, aggression) in a pedigreed population of Mediterranean field crickets (Gryllus bimaculatus). Path analyses showed that behaviours mediated some genetic relationships between life history traits, though not those involved in trade-offs. Thus, while specific predictions of POLS theory were not supported, genetic integration of behaviour and life history was present. This implies a major role for risky behaviours in life history evolution.
Diatoms dominate the eukaryotic metatranscriptome during spring in coastal ‘dead zone’ sediments
Authors: Broman Elias , Sachpazidou Varvara , Dopson Mark , Hylander Samuel
Published: October 2017

An important characteristic of marine sediments is the oxygen concentration that affects many central metabolic processes. There has been a widespread increase in hypoxia in coastal systems (referred to as ‘dead zones’) mainly caused by eutrophication. Hence, it is central to understand the metabolism and ecology of eukaryotic life in sediments during changing oxygen conditions. Therefore, we sampled coastal ‘dead zone’ Baltic Sea sediment during autumn and spring, and analysed the eukaryotic metatranscriptome from field samples and after incubation in the dark under oxic or anoxic conditions. Bacillariophyta (diatoms) dominated the eukaryotic metatranscriptome in spring and were also abundant during autumn. A large fraction of the diatom RNA reads was associated with the photosystems suggesting a constitutive expression in darkness. Microscope observation showed intact diatom cells and these would, if hatched, represent a significant part of the pelagic phytoplankton biomass. Oxygenation did not significantly change the relative proportion of diatoms nor resulted in any major shifts in metabolic ‘signatures’. By contrast, diatoms rapidly responded when exposed to light suggesting that light is limiting diatom development in hypoxic sediments. Hence, it is suggested that diatoms in hypoxic sediments are on ‘standby’ to exploit the environment if they reach suitable habitats.
Head movements quadruple the range of speeds encoded by the insect motion vision system in hawkmoths
Authors: Windsor Shane P. , Taylor Graham K.
Published: October 2017

Flying insects use compensatory head movements to stabilize gaze. Like other optokinetic responses, these movements can reduce image displacement, motion and misalignment, and simplify the optic flow field. Because gaze is imperfectly stabilized in insects, we hypothesized that compensatory head movements serve to extend the range of velocities of self-motion that the visual system encodes. We tested this by measuring head movements in hawkmoths
Hyles lineata
responding to full-field visual stimuli of differing oscillation amplitudes, oscillation frequencies and spatial frequencies. We used frequency-domain system identification techniques to characterize the head's roll response, and simulated how this would have affected the output of the motion vision system, modelled as a computational array of Reichardt detectors. The moths' head movements were modulated to allow encoding of both fast and slow self-motion, effectively quadrupling the working range of the visual system for flight control. By using its own output to drive compensatory head movements, the motion vision system thereby works as an adaptive sensor, which will be especially beneficial in nocturnal species with inherently slow vision. Studies of the ecology of motion vision must therefore consider the tuning of motion-sensitive interneurons in the context of the closed-loop systems in which they function.
Divergence in cryptic leaf colour provides local camouflage in an alpine plant
Authors: Niu Yang , Chen Zhe , Stevens Martin , Sun Hang
Published: October 2017

The efficacy of camouflage through background matching is highly environment-dependent, often resulting in intraspecific colour divergence in animals to optimize crypsis in different visual environments. This phenomenon is largely unexplored in plants, although several lines of evidence suggest they do use crypsis to avoid damage by herbivores. UsingCorydalis hemidicentra,an alpine plant with cryptic leaf colour, we quantified background matching between leaves and surrounding rocks in five populations based on an approximate model of their butterfly enemy's colour perception. We also investigated the pigment basis of leaf colour variation and the association between feeding risk and camouflage efficacy. We show that plants exhibit remarkable colour divergence between populations, consistent with differences in rock appearances. Leaf colour varies because of a different quantitative combination of two basic pigments—chlorophyll and anthocyanin—plus different air spaces. As expected, leaf colours are better matched against their native backgrounds than against foreign ones in the eyes of the butterfly. Furthermore, improved crypsis tends to be associated with a higher level of feeding risk. These results suggest that divergent cryptic leaf colour may have evolved to optimize local camouflage in various visual environments, extending our understanding of colour evolution and intraspecific phenotype diversity in plants.
Persistent and plastic effects of temperature on DNA methylation across the genome of threespine stickleback (Gasterosteus aculeatus)
Authors: Metzger David C. H. , Schulte Patricia M.
Published: October 2017

Epigenetic mechanisms such as changes in DNA methylation have the potential to affect the resilience of species to climate change, but little is known about the response of the methylome to changes in environmental temperature in animals. Using reduced representation bisulfite sequencing, we assessed the effects of development temperature and adult acclimation temperature on DNA methylation levels in threespine stickleback (Gasterosteus aculeatus). Across all treatments, we identified 2130 differentially methylated cytosines distributed across the genome. Both increases and decreases in temperature during development and with thermal acclimation in adults increased global DNA methylation levels. Approximately 25% of the differentially methylated regions (DMRs) responded to both developmental temperature and adult thermal acclimation, and 50 DMRs were common to all treatments, demonstrating a core response of the epigenome to thermal change at multiple time scales. We also identified differentially methylated loci that were specific to a particular developmental or adult thermal response, which could facilitate the accumulation of epigenetic variation between natural populations that experience different thermal regimes. These data demonstrate that thermal history can have long-lasting effects on the epigenome, highlighting the role of epigenetic modifications in the response to temperature change across multiple time scales.
Earless toads sense low frequencies but miss the high notes
Authors: Womack Molly C. , Christensen-Dalsgaard Jakob , Coloma Luis A. , Chaparro Juan C. , Hoke Kim L.
Published: October 2017

Sensory losses or reductions are frequently attributed to relaxed selection. However, anuran species have lost tympanic middle ears many times, despite anurans' use of acoustic communication and the benefit of middle ears for hearing airborne sound. Here we determine whether pre-existing alternative sensory pathways enable anurans lacking tympanic middle ears (termed earless anurans) to hear airborne sound as well as eared species or to better sense vibrations in the environment. We used auditory brainstem recordings to compare hearing and vibrational sensitivity among 10 species (six eared, four earless) within the Neotropical true toad family (Bufonidae). We found that species lacking middle ears are less sensitive to high-frequency sounds, however, low-frequency hearing and vibrational sensitivity are equivalent between eared and earless species. Furthermore, extratympanic hearing sensitivity varies among earless species, highlighting potential species differences in extratympanic hearing mechanisms. We argue that ancestral bufonids may have sufficient extratympanic hearing and vibrational sensitivity such that earless lineages tolerated the loss of high frequency hearing sensitivity by adopting species-specific behavioural strategies to detect conspecifics, predators and prey.
Deceptive vocal duets and multimodal display in a songbird
Authors: Ręk Paweł , Magrath Robert D.
Published: October 2017

Many group-living animals cooperatively signal to defend resources, but what stops deceptive signalling to competitors about coalition strength? Cooperative-signalling species include mated pairs of birds that sing duets to defend their territory. Individuals of these species sometimes sing ‘pseudo-duets’ by mimicking their partner's contribution, but it is unknown if these songs are deceptive, or why duets are normally reliable. We studied pseudo-duets in Australian magpie-larks,Grallina cyanoleuca, and tested whether multimodal signalling constrains deception. Magpie-larks give antiphonal duets coordinated with a visual display, with each sex typically choosing a different song type within the duet. Individuals produced pseudo-duets almost exclusively during nesting when partners were apart, but the two song types were used in sequence rather than antiphonally. Strikingly, birds hid and gave no visual displays, implying deceptive suppression of information. Acoustic playbacks showed that pseudo-duets provoked the same response from residents as true duets, regardless of whether they were sequential or antiphonal, and stronger response than that to true duets consisting of a single song type. By contrast, experiments with robot models showed that songs accompanied by movements of two birds prompted stronger responses than songs accompanied by movements of one bird, irrespective of the number of song types or singers. We conclude that magpie-larks used deceptive pseudo-duets when partners were apart, and suppressed the visual display to maintain the subterfuge. We suggest that the visual component of many species' duets provides the most reliable information about the number of signallers and may have evolved to maintain honesty in duet communication.
Diet predicts milk composition in primates
Authors: Blomquist Gregory E. , Hinde Katie , Milligan Newmark Lauren A.
Published: October 2017

Mammalian mothers pay heavy energetic costs to fuel the growth of their offspring. These costs are highest during lactation. Energy transmitted to offspring in the form of milk must ultimately come from the maternal diet, but there have been few comparative studies of the relationship between milk properties and mammalian diets. We used interspecific data on primate milk composition and wild diets to establish that concentrations of milk protein and sugar are predicted by diet independent of maternal mass, litter mass, and infant parking behavior such that increasing folivory or faunivory increases protein concentration but decreases sugar concentration. Milk energy density is unrelated to diet, though infant parking species do produce more energy-dense milk. While parking effects have been previously explained as a result of mother-infant separation, the mechanisms causing the relationship between nutrient packaging in milk and maternal diet are currently unclear. However, they likely reflect evolved differences in maternal energetics related to maternal foraging ecology, infant growth patterns, or the relative dietary abundance of nutrients costly to synthesize in milk among primate species.
Independent erosion of conserved transcription factor binding sites points to shared hindlimb, vision, and scrotum loss in different mammals
Authors: Berger Mark J. , Wenger Aaron M. , Guturu Harendra , Bejerano Gill
Published: October 2017

Genetic variation incis-regulatory elements is thought to be a major driving force in morphological and physiological change. However, identifying transcription factor binding events which code for complex traits remains a challenge, motivating novel means of detecting putatively important binding events. Using a curated set of 1,154 high-quality transcription factor motifs, we demonstrate that independently eroded binding sites are enriched for independently lost traits in three distinct pairs of placental mammals. We show that these independently eroded events pinpoint the loss of hindlimbs in dolphin and manatee, degradation of vision in naked mole-rat and star-nosed mole, and the loss of scrotum in white rhinoceros and Weddell seal. Our study exhibits a novel methodology to detectcis-regulatory mutations which help explain a portion of the molecular mechanism underlying complex trait formation and loss.

Author Summary

Evolution has produced an astounding variety of species with incredibly diverse phenotypes. A central question in evolutionary developmental biology is how (and which) DNA evolves to encode all of these different traits. A prevailing hypothesis is that changes in regulatory DNA, short stretches of DNA which control the expression of protein-coding genes, drive important differences in trait formation between species. The basic building block of regulatory DNA is thought to be transcription factor binding sites, shortl genomic sequences which attract proteins whose central role is to control the rate of transcription. In this study, we asked whether the independent erosion of otherwise highly conserved transcription factor binding sites points to a trait shared between species which have undergone similar adaptations. We show that our method is able to point to the loss of hindlimbs in dolphin and manatee, poor vision in naked mole-rat and star-nosed mole, and loss of scrotum in Weddell seal and white rhinoceros. Overall, our study exhibits a means of detecting evolutionarily important genomic regions which help explain a portion of complex trait loss and retention.
Single-exposure visual memory judgments are reflected in IT cortex
Authors: Meyer Travis , Rust Nicole C.
Published: October 2017

Our visual memory percepts of whether we have encountered specific objects or scenes before are hypothesized to manifest as decrements in neural responses in inferotemporal cortex (IT) with stimulus repetition. To evaluate this proposal, we recorded IT neural responses as two monkeys performed a single-exposure visual memory task designed to measure the rates of forgetting with time. We found that a weighted linear read-out of IT was a better predictor of the monkeys’ forgetting rates and reaction time patterns than a strict instantiation of the repetition suppression hypothesis, expressed as a total spike count scheme. Behavioral predictions could be attributed to visual memory signals that were reflected as repetition suppression and were intermingled with visual selectivity, but only when combined across the most sensitive neurons.
Temporal differentiation of bovine airway epithelial cells grown at an air-liquid interface
Authors: Cozens Daniel , Sutherland Erin , Marchesi Francesco , Taylor Geraldine , Berry Catherine , Davies Robert
Published: October 2017

The respiratory epithelium is exposed to assault by toxins and pathogens through the process of inhalation, which has numerous implications on both human and animal health. As such, there is a need to develop and characterise anin vitromodel of the airway epithelium to study respiratory pathologies during infection or toxicology experiments. This has been achieved by growing airway epithelial cells at an air-liquid interface (ALI). Characterisation of ALI models are not well-defined for airway epithelial cells derived from non-human species. In this study we have fully characterised a bovine airway epithelial cell models (AECM) grown at an ALI in relation toex vivotissue. The morphology of the model was monitored at three day intervals, to identify the time-period at which the culture was optimally differentiated. The model was shown to be fully-differentiated by day 21 post-ALI. The culture formed a stereotypical pseudostratified, columnar epithelium containing the major cell types of the bronchial epithelium (ciliated-, goblet- and basal cells). Once fully differentiated the bovine AECM displayed both barrier function, through the formation of tight-junctions, and active mucociliary clearance, important properties of the mucosal barrier. The bovine bronchial epithelial cells remained stable for three weeks, with no evidence of deterioration or dedifferentiation. The window in which the model displayed full differentiation was determined to be between day 21-42 post-ALI. Through comparison withex vivotissue derived from donor animals, our bovine AECM was shown to be highly representative of thein vivobovine bronchial epithelium and can be utilised in the study of respiratory pathologies.