bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling the interaction between relativistic and non-relativistic winds in binary pulsar systems: strong magnetization of the pulsar wind
Authors: Bogovalov S V , Khangulyan D , Koldoba A , Ustyugova G V , Aharonian F
Published: October 2019

We present a numerical study of the properties of the flow produced by the collision of a magnetized anisotropic pulsar wind with the circumbinary environment. We focus on studying the impact of the high wind magnetization on the geometrical structure of the shocked flow. This work is an extension of our earlier studies that focused on a purely hydrodynamic interaction and weak wind magnetization. We consider the collision in the axisymmetric approximation, i.e. the pulsar rotation axis is assumed to be oriented along the line between the pulsar and the optical star. The increase of the magnetization results in the expansion of the opening cone in which the shocked pulsar wind propagates. This effect is explained in the frameworks of the conventional theory of collimation of magnetized winds. This finding has a direct implication for scenarios that involve Doppler boosting as the primary mechanism behind the GeV flares detected with the Fermi Large Area Telescope from PSR B1259−63/LS 2883. The maximum enhancement of the apparent emission is determined by the ratio of 4$\pi$ to the solid in which the shocked pulsar wind propagates. Our simulations suggest that this enhancement factor is decreased by the impact of the magnetic field.
Host Abundance and Identity Determine the Epidemiology and Evolution of a Generalist Plant Virus in a Wild Ecosystem
Authors: Rodríguez-Nevado Cristina , G. Gavilán Rosario , Pagán Israel
Published: October 2019

Increasing evidence indicates that in wild ecosystems plant viruses are important ecological agents, and with potential to jump into crops, but only recently have the diversity and population dynamics of wild plant viruses begun to be explored. Theory proposes that biotic factors (e.g., ecosystem biodiversity, host abundance, and host density) and climatic conditions would determine the epidemiology and evolution of wild plant viruses. However, these predictions seldom have been empirically tested. For 3 years, we analyzed the prevalence and genetic diversity of Potyvirus species in preserved riparian forests of Spain. Results indicated that potyviruses were always present in riparian forests, with a novel generalist potyvirus species provisionally named Iberian hop mosaic virus (IbHMV), explaining the largest fraction of infected plants. Focusing on this potyvirus, we analyzed the biotic and climatic factors affecting virus infection risk and population genetic diversity in its native ecosystem. The main predictors of IbHMV infection risk were host relative abundance and species richness. Virus prevalence and host relative abundance were the major factors determining the genetic diversity and selection pressures in the virus population. These observations support theoretical predictions assigning these ecological factors a key role in parasite epidemiology and evolution. Finally, our phylogenetic analysis indicated that the viral population was genetically structured according to host and location of origin, as expected if speciation is largely sympatric. Thus, this work contributes to characterizing viral diversity and provides novel information on the determinants of plant virus epidemiology and evolution in wild ecosystems.
It's the Moments That Matter
Authors: Kennedy Maureen Shawn
Published: October 2019

Brief encounters and events can sometimes change lives.
DACA Recipients Seeking RN Licensure: On a Road to Nowhere?
Authors: Sofer Dalia
Published: October 2019

For many who complete a nursing curriculum, the dream ends with a diploma.
ANA Adopts New Presidential Election Policy
Authors: Myers Carole R.
Published: October 2019

The organization determines candidate endorsement is no longer beneficial.
New Drug Indications for Pediatric Type 2 Diabetes, Cystic Fibrosis, and Hospital-Acquired and Ventilator-Associated Bacterial Pneumonia
Authors: Aschenbrenner Diane S.
Published: October 2019

Liraglutide (Victoza) is now approved for use in children 10 years and older with type 2 diabetes.

Tezacaftor–ivacaftor (Symdeko) is now approved for children six years and older with cystic fibrosis and a specific genetic mutation. Previously, the combination drug was approved for children ages 12 and older.

The combination antiinfective ceftolozane–tazobactam (Zerbaxa) is now approved to treat hospital-acquired and ventilator-associated bacterial pneumonia in patients 18 years and older. The dose of ceftolozane–tazobactam is higher for this indication than for others.
Special Feature: Countering Vaccine Misinformation
Authors: Danielson Lindsey , Marcus Blima , Boyle Lori
Published: October 2019

Evidence consistently shows that vaccines are safe, effective, and cost-efficient. Yet preventable outbreaks of infectious diseases are occurring in the United States, leading to a strong public response and intense scrutiny of the antivaccine movement and its persistent spread of misinformation. Social media has been a major platform for such misinformation, and recent examinations have found that nurses are not exempt from engaging in antivaccine discourse.

By practicing evidence-based care, addressing health literacy, and becoming involved in public health policy, nurses can be excellent advocates for immunization and may help prevent additional outbreaks of preventable diseases.
Long-Term Inhaled Antipseudomonal Antibiotics in Cystic Fibrosis
Authors: Greenslade Rebecca
Published: October 2019

Editor's note: This is a summary of a nursing care–related systematic review from the Cochrane Library. For more information, see http://nursingcare.cochrane.org.
Unnecessary Antibiotic Prophylaxis for Dental Procedures is Widespread
Authors: Rosenberg Karen
Published: October 2019

According to this study:

More than 80% of antibiotic prescriptions for infection prophylaxis before dental procedures are unnecessary.

Antimicrobial stewardship in dental practices is needed.
When ‘Love’ = Death
Authors: Brown Theresa
Published: October 2019

We all need to take heed and ask questions.
The Last One
Authors: Wiedenhoeft Frances
Published: October 2019

What would it take to make you really appreciate the precious moments of your life?
Maria, Planned Parenthood, and how nursing chose me
Authors: Diamond Ilana
Published: October 2019

This article examines how one patient and the recent political climate surrounding Planned Parenthood influenced a college graduate with career aspirations in criminology to pursue nursing instead.
Fluid Overload and Risk of Mortality in Critically Ill Patients
Authors: Gomes Jessica , Pesavento Marcele Liliane , de Freitas Flavia Fernandes Manfredi , de Andrade Coelho Filipe Utuari
Published: October 2019

Background

Fluid overload (FO) is a condition present in critical care units, and it is associated with clinical complications and worse outcomes for severe patients.

Objective

The aim of this study was to verify if FO is a risk factor for mortality in critically ill patients.

Methods

Retrospective study performed in a Brazilian intensive care unit, from January to March 2016, with patients older than 18 years and hospitalized for more than 24 hours. Demographic and clinical data, as well as fluid balance and overload, were analyzed to verify the risk factors for mortality. A logistic regression model was elaborated, and significance was set at P < .05.

Results

There were 158 patients included, of which only 13 (8.2%) presented FO. Mortality was verified in individuals 30 (18.9%), of whom only 7 (23.3%) developed FO, which was lower in survivors 6 (4.9%), P = .001. In the simple regression model, the FO was significant (odds ratio [OR], 6.23; 95% confidence interval [CI], 2.04–19.53), P = .001. However, in the multiple regression model, there were significant findings only for mechanical ventilation (OR, 5.86; 95% CI, 2.10–18.12, P = .001), acute kidney injury (OR, 4.05; 95% CI, 1.53–11; P = .001), and noradrenaline (OR, 3.85; 95% CI, 1.01–9.51; P = .041); FO was not significant (OR, 3.68; 95% CI, 0.91–15.55; P = .069).

Conclusion

Fluid overload is higher in patients who died. Therefore, it was not considered a risk factor for mortality.
Utilizing an Integrated Learning Experience in a Senior Undergraduate Nursing Program
Authors: Foley Jo Anne , Mason Virginia M. , Manning Karen
Published: October 2019

Integration of nursing classroom didactics with clinical and simulation experiences is crucial to obtaining improved student learning outcomes and successful academic achievement. According to the Institute of Medicine (2010), to ensure the delivery of safe, patient-centered care across settings, the nursing education system must be improved. Patient needs have become more complicated, and nurses need to attain requisite competencies to deliver high-quality care. An important aim is to increase active learning behaviors and maintain student engagement, which will foster an effort to learn and meet the complex needs of patients today. The integration of clinical and simulation with theory concepts can contribute to successful student development, confidence, self-efficacy, and reenforced desire to learn which is the key to success and competence development. Teamwork and collaboration are valued in nursing educational objectives as well as in the workplace. Blending a shared vision and mutual expectations helps to meet goals.
Asymptomatic microscopic hematuria in women
Authors: Whiteside James L. , Yuen Hoi T.H.
Published: October 2019

Purpose of review

The purpose of this review is to summarize the problem of asymptomatic microscopic hematuria (AMH) in women and the most recent publications on the topic.

Recent findings

Urologic malignancy is rarely associated with AMH in low-risk women. Screening for urologic malignancy includes upper urinary tract imaging and cystoscopy. Renal ultrasound is a cost-effective first-line imaging modality in patients with AMH. Multiphasic computed tomography (CT) urography increases healthcare costs, the risk of secondary malignancy due to cumulative radiation exposure, and the discovery of incidental benign findings resulting in additional work-up. Cystoscopy is universally recommended as a diagnostic test in the evaluation of AMH but it is not without harm. Reliable risk factors for urologic malignancy in women are age, smoking, and possibly the presence of visible blood in the urine. Given the infrequency of these cancers and the performance characteristics of diagnostic testing in this context there is a need for better diagnostic strategies incorporating these risk factors in estimating the woman's risk.

There is a need for sex-specific guidelines to risk stratify diagnostic evaluation for urologic malignancy in women with AMH. The low prevalence of these malignancies in women render diagnostic testing (e.g., cystoscopy and multiphasic CT urography) less impactful and pose unwarranted risk and significant healthcare costs.
Surgically-Relevant Anatomy of the External Auditory Canal Bulge and Scutum
Authors: Kennel Christopher E. , Puricelli Michael D. , Rivera Arnaldo L.
Published: October 2019

Hypothesis:

Anatomic study of the external auditory canal's (EAC) anterior bulge, scutum, and ossicular chain will generate knowledge applicable to safe ear surgery and instrument design.

Background:

The EAC contains two structures that obscure view of the middle ear: the anterior bulge and the scutum. The dimensions of these structures and their relationships to the ossicular chain have not been previously described.

Methods:

Cadaveric temporal bones underwent computed tomography scanning, and three-dimensional reconstructions were created. Dimensions and angles of the EAC, its anterior bulge and scutum were measured. Distances to ossicular landmarks and the facial nerve were examined.

Results:

The anterior EAC had a swan-neck shape. The thinnest portion was located medially and correlated with the canal thickness at the anterior bulge. However the thickness of the anterior bulge was not correlated with its angulation. The scutum averaged 3.8 mm long with a base thickness of 2.3 mm and a mean tip angle of 33 degrees. The short process of the incus was significantly closer to the scutum than other ossicular landmarks.

Conclusion:

Prominent anterior canal bulges are formed by posterior temporomandibular joints, not thicker bone. The scutum has asymmetric distances to various portions of the ossicles with the incus short process sometimes as close as 0.2 mm, placing it at risk of injury.
Implications of serial coronary computed tomography angiography in the evaluation of coronary plaque progression
Authors: Dahal Suraj , Budoff Matthew J.
Published: October 2019

Purpose of review

The purpose is to review the use of coronary computed tomography (CT) angiography to assess coronary plaque burden/progression and to discuss about recent clinical trials that have utilized this imaging modality to study the effect of new pharmacotherapies on plaque burden/progression.

Recent findings

There are numerous clinical trials that have utilized coronary CT angiography to demonstrate the potential benefits of statins, apixaban, rivaroxaban, aged garlic extract, biologic agents, and omega-3 fatty acids to reduce coronary plaque progression. Coronary CT angiography can identify high-risk plaques and can also quantify total plaque burden, both of which are independent risk factors to predict major adverse cardiac events.

Coronary heart disease remains one of the leading cause of mortality in the world. Utilizing coronary CT angiography, it is possible to identify rupture-prone plaques and also to quantify the total plaque burden. New pharmacotherapies that have the potential to reduce plaque progression have been used in clinical trials and these trials have utilized coronary CT angiography to track coronary atheroma progression. In future, we will see frequent utilization of coronary CT angiography to track coronary atheroma.
Ethanol Intoxication of Young Children
Authors: Gaw Christopher E. , Osterhoudt Kevin C.
Published: October 2019

Ethanol intoxication of infants and young children can be a challenging diagnosis in the pediatric emergency department, and features of the poisoning may differ in comparison with adolescents. The sources of ethanol exposures in this age are varied and include unintentional, malicious, and iatrogenic etiologies. Young children exposed to ethanol often present with mixed clinical signs and symptoms that may not fit the traditional ethanol or sedative-hypnotic toxidrome. Pediatric ethanol intoxications are often managed supportively, and recovery is usually rapid. The purpose of this review is to describe the sources of ethanol poisoning among children 6 years and younger, highlight presenting symptoms and pharmacokinetic considerations unique to this age group, and review management strategies. In addition, published cases of ethanol poisoning due to ingestion among young infants are compiled for presentation.
Listen and Be Ready to Shift: How Racial Equity and Community Leadership Launched “Communities of Opportunity”
Authors: Wysen Kirsten
Published: October 2019

Multisector partnerships that put racial equity and community leadership at their center can create pathways to healthy communities. With funding from the Seattle Foundation and King County government, Communities of Opportunity was launched in 2014 to close gaps by place and by race in health outcomes and in measures of 3 social determinants—employment, housing, and social environment. The initiative is governed by a multisector partnership with community leaders in the majority. Relationships and decisions made during Communities of Opportunity's early years led to an expansion of the work from a $1 million per year place-based focus to an $8 million per year policy and system change enterprise. The initiative now funds 68 nonprofits to improve racial equity by increasing community capacity, investing in leadership development, and making policy changes. A committed group of community leaders worked with the funders to create an innovative structure that redresses past and current racial injustices and supports local leaders acting on ambitious priorities. A shared analysis of structural racism in the past and the present can deepen relationships and increase local government and funder credibility. When health departments and funders create the space for community leadership, initiatives can have broader reach and greater sustainability. We are in the early stages of developing the evidence base for improving community health equity and further work is needed to identify and disseminate successful processes and interventions.
SMAD6 Genotype Predicts Neurodevelopment in Nonsyndromic Craniosynostosis
Authors: Wu Robin T. , Timberlake Andrew T. , Abraham Paul F. , Gabrick Kyle S. , Lu Xiaona , Peck Connor J. , Sawh-Martinez Rajendra F. , Steinbacher Derek M. , Alperovich Michael A. , Persing John A.
Published: October 2019

Background:

De novo or rare transmitted mutations in the SMAD6 gene affect 7 percent of midline nonsyndromic synostosis patients. This study aimed to determine the neurocognitive sequelae of SMAD6 synostosis.

Methods:

Nonsyndromic synostosis patients 6 years or older with SMAD6 mutations and non-SMAD6 nonsyndromic synostosis controls were recruited. All patients completed a double-blinded neurodevelopmental battery (i.e., Wechsler Fundamentals, Wechsler Abbreviated Scale of Intelligence, Beery-Buktenica Developmental test), and parents/guardians completed behavioral surveys (Behavior Rating Inventory of Executive Function and Behavior Rating System for Children).

Results:

Twenty-eight patients participated: 10 known SMAD6 patients (average age, 10 years; 1 female; eight metopic and two sagittal; nine treated with cranial vault remodeling and one treated with strip craniectomy) and 18 non-SMAD6 controls (age, 9.5 years; three female; 12 metopic and six sagittal; 17 treated with cranial vault remodeling and one treated with strip craniectomy). There were no differences between any demographics. Testing age, surgical age, parental education, and household income correlated with cognition (p < 0.05). After controlling for these factors, SMAD6 patients performed worse on numerical operations (p = 0.046), performance intelligence quotient (p = 0.018), full-scale intelligence quotient (p = 0.010), and motor coordination (p = 0.043) compared to age/race/gender/synostosis/operation-matched controls. On behavioral surveys, SMAD6 patients scored worse on 14 assessments, including aggression, communication, and behavior.

Conclusions:

This prospective double-blinded study revealed that neuropsychiatric development of nonsyndromic synostosis may be under genetic control. SMAD6 mutations led to poorer mathematics, performance intelligence quotient, full-scale intelligence quotient, and motor coordination, even after controlling for exogenous factors. Genetic testing may be critical for advocating early adjunctive neurodevelopmental therapy.

CLINICAL QUESTION/LEVEL OF EVIDENCE:

Risk, II.
Definition of Immunological Nonresponse to Antiretroviral Therapy: A Systematic Review
Authors: Rb-Silva Rita , Goios Ana , Kelly Christine , Teixeira Pedro , João Cristina , Horta Ana , Correia-Neves Margarida
Published: October 2019

Background:

Terms and criteria to classify people living with HIV on antiretroviral therapy who fail to achieve satisfactory CD4+ T-cell counts are heterogeneous, and need revision and summarization.

Methods:

We performed a systematic review of PubMed original research articles containing a set of predefined terms, published in English between January 2009 and September 2018. The search retrieved initially 1360 studies, of which 103 were eligible. The representative terminology and criteria were extracted and analyzed.

Results:

Twenty-two terms and 73 criteria to define the condition were identified. The most frequent term was “immunological nonresponders” and the most frequent criterion was “CD4+ T-cell count <350 cells/µL after ≥24 months of virologic suppression.” Most criteria use CD4+ T-cell counts as a surrogate, either as an absolute value before antiretroviral therapy initiation or as a change after a defined period of time. Distinct values and time points were used. Only 9 of the 73 criteria were used by more than one independent research team. Herein we propose 2 criteria that could help to reach a consensus.

Conclusions:

The high disparity in terms and criteria here reported precludes data aggregation and progression of the knowledge on this condition, because it renders impossible to compare data from different studies. This review will foster the discussion of terms and criteria to achieve a consensual definition.
System Factors Affecting Patient Safety in the OR
Authors: Adams-McGavin Robert Chris , Jung James J. , van Dalen Anne S. H. M. , Grantcharov Teodor P. , Schijven Marlies P.
Published: October 2019

Objective:

The objective of this study is to determine the characteristics and frequency of intraoperative safety threats and resilience supports using a human factors measurement tool.

Background:

Human factors analysis can provide insight into how system elements contribute to intraoperative adverse events. Empiric evidence on safety threats and resilience in surgical practice is lacking.

Methods:

A cross-sectional study of 24 patients undergoing elective laparoscopic general surgery at a single center in the Netherlands from May to November, 2017 was conducted. Video, audio, and patient physiologic data from all included procedures were obtained through a multichannel synchronized recording device. Trained analysts reviewed the recordings and coded safety threats and resilience supports. The codes were categorized into 1 of 6 categories (person, task, tools and technology, physical environment, organization, and external environment).

Results:

A median of 14 safety threats [interquartile range (IQR) 11–16] and 12 resilience supports (IQR 11–16) were identified per case. Most safety threat codes (median 9, IQR 7–12) and resilience support codes (median 10, IQR 7–12) were classified in the person category. The organization category contained a median of 2 (IQR 1–2) safety threat codes and 2 (IQR 2–3) resilience support codes per case. The tools and technology category contributed a small number of safety threats (median 1 per case, IQR 0–1), but rarely provided resilience support.

Conclusions:

Through a detailed human factors analysis of elective laparoscopic general surgery cases, this study provided a quantitative analysis of the existing safety threats and resilience supports in a modern endoscopic operating room.
Multicellular behaviour enables cooperation in microbial cell aggregates
Authors: Ebrahimi Ali , Schwartzman Julia , Cordero Otto X.
Published: October 2019

Oligosaccharides produced from the extracellular hydrolysis of biological materials can act as common goods that promote cooperative growth in microbial populations, whereby cell–cell aggregation increases both the per capita availability of resources and the per-cell growth rate. However, aggregation can also have detrimental consequences for growth, as gradients form within aggregates limiting the resource accessibility. We built a computational model, which predicts cooperation is restricted in dense cell aggregates larger than 10 µm because of the emergence of polymer and oligomer counter gradients. We compared these predictions to experiments performed with two well-studied alginate-degrading strains of
Vibrio splendidus
, which varied in their ability to secrete alginate lyase. We observed that both strains can form large aggregates (less than 50 µm), overcoming diffusion limitation by rearranging their internal structure. The stronger enzyme producer grew non-cooperatively and formed aggregates with internal channels that allowed exchange between the bulk environment and the aggregate, whereas the weak enzyme producer showed strongly cooperative growth and formed dense aggregates in which cells near the core mixed by active swimming. Our simulations suggest that the mixing and channelling reduce diffusion limitation and allow cells to uniformly grow in aggregates. Together, these data demonstrate that bacterial behaviour can help overcome competition imposed by resource gradients within cell aggregates.

This article is part of a discussion meeting issue ‘Single cell ecology’.
Transparent and Reproducible Research Practices in the Surgical Literature
Authors: Hughes Taylor , Niemann Andrew , Tritz Daniel , Boyer Kryston , Robbins Hal , Vassar Matt
Published: October 2019

Previous studies have established a baseline of minimal reproducibility in the social science and biomedical literature. Clinical research is especially deficient in factors of reproducibility. Surgical journals contain fewer clinical trials than non-surgical ones, suggesting that it should be easier to reproduce the outcomes of surgical literature. In this study, we evaluated a broad range of indicators related to transparency and reproducibility in a random sample of 300 articles published in surgery-related journals between 2014 and 2018. A minority of our sample made available their materials (2/186, 95% C.I. 0–2.2%), protocols (1/196, 0–1.3%), data (19/196, 6.3–13%), or analysis scripts (0/196, 0–1.9%). Only one study was adequately pre-registered. No studies were explicit replications of previous literature. Most studies (162/292 50–61%) declined to provide a funding statement, and few declared conflicts of interest (22/292, 4.8–11%). Most have not been cited by systematic reviews (183/216, 81–89%) or meta-analyses (188/216, 83–91%), and most were behind a paywall (187/292, 58–70%). The transparency of surgical literature could improve with adherence to baseline standards of reproducibility.
Structural and mechanical remodeling of the cytoskeleton maintains tensional homeostasis in 3D microtissues under acute dynamic stretch
Authors: Walker Matthew , Rizzuto Pauline , Godin Michel , Pelling Andrew E.
Published: October 2019

When stretched, cells cultured on 2D substrates share a universal softening and fluidization response that arises from poorly understood remodeling of well-conserved cytoskeletal elements. It is known, however, that the structure and distribution of the cytoskeleton is profoundly influenced by the dimensionality of a cell’s environment. Therefore, in this study we aimed to determine whether cells cultured in a 3D matrix share this softening behavior and to link it to cytoskeletal remodeling. To achieve this, we developed a high-throughput approach to measure the dynamic mechanical properties of cells and allow for sub-cellular imaging within physiologically relevant 3D microtissues. We found that fibroblast, smooth muscle and skeletal muscle microtissues strain softened but did not fluidize, and upon loading cessation, they regained their initial mechanical properties. Furthermore, microtissue prestress decreased with the strain amplitude to maintain a constant mean tension. This adaptation under an auxotonic condition resulted in lengthening. A filamentous actin cytoskeleton was required, and responses were mirrored by changes to actin remodeling rates and visual evidence of stretch-induced actin depolymerization. Our new approach for assessing cell mechanics has linked behaviors seen in 2D cultures to a 3D matrix, and connected remodeling of the cytoskeleton to homeostatic mechanical regulation of tissues.
Automated highly multiplexed super-resolution imaging of protein nano-architecture in cells and tissues
Authors: Klevanski Maja , Herrmannsdoerfer Frank , Venkataramani Varun , Sass Steffen , Heilemann Mike , Kuner Thomas
Published: October 2019

Understanding the nano-architecture of protein machines in diverse sub-cellular compartments remains a challenge despite rapid progress in super-resolution microscopy. While singlemolecule localization microscopy techniques allow the visualization and identification of cellular structures with near-molecular resolution, multiplex-labeling of tens of target proteins within the same sample has not yet been achieved routinely. However, single sample multiplexing is essential to detect patterns that threaten to get lost in multi-sample averaging. Here, we report maS3TORM (multiplexed automated serial staining stochastic optical reconstruction microscopy), a microscopy approach capable of fully automated 3D dSTORM imaging and solution exchange employing a re-staining protocol to achieve highly multiplexed protein localization within individual biological samples. We demonstrate 3D super-resolution images of 15 target proteins in single cultured cells and 16 targets in individual neuronal tissue samples with <10 nm localization precision. This allowed us to define novel nano-architectural features of protein distribution within the presynaptic nerve terminal.
Parallel and non-parallel changes of the gut microbiota during trophic diversification in repeated young adaptive radiations of sympatric cichlid fish
Authors: Härer Andreas , Torres-Dowdall Julián , Rometsch Sina , Yohannes Elizabeth , Machado-Schiaffino Gonzalo , Meyer Axel
Published: October 2019

Recent increases in understanding the ecological and evolutionary roles of microbial communities has underscored their importance for their hosts’ biology. Yet, little is known about gut microbiota dynamics during early stages of ecological diversification and speciation. We studied the gut microbiota of extremely young adaptive radiations of Nicaraguan crater lake cichlid fish (Amphilophus cf. citrinellus) to test the hypothesis that parallel evolution in trophic ecology is associated with parallel changes of the gut microbiota. Bacterial communities of the water (eDNA) and guts were highly distinct, indicating that the gut microbiota is shaped by host-specific factors. Across individuals of the same crater lake, differentiation in trophic ecology was associated with gut microbiota differentiation, suggesting that diet affects the gut microbiota. However, differences in trophic ecology were much more pronounced across than within species whereas little evidence was found for similar patterns in taxonomic and functional changes of the gut microbiota. Across the two crater lakes, we could not detect evidence for parallel changes of the gut microbiota associated with trophic ecology. Similar cases of non-parallelism have been observed in other recently diverged fish species and might be explained by a lack of clearly differentiated niches during early stages of ecological diversification.
Perceptual learning evidence for an interval- and modality-invariant representation of subsecond time
Authors: Xiong Ying-Zi , Guan Shu-Chen , Yu Cong
Published: October 2019

A central theme in time perception research is whether subsecond timing relies on a dedicated centralized clock, or on distributed neural temporal dynamics. A fundamental constraint is the interval- and modality-specificity in perceptual learning of temporal interval discrimination (TID), which argues against a dedicated centralized clock, but is more consistent with multiple distributed mechanisms. Here we demonstrated an abstract, interval- and modality-invariant, representation of subsecond time in the brain. Participants practiced TID at a specific interval (100 ms), and received exposure to a transfer interval (200 ms), or to a different auditory/visual modality, through training of an orthogonal task. This double training enabled complete transfer of TID learning to the untrained interval, and mutual complete transfer between visual and auditory modalities. These results demonstrate an interval- and modality-invariant representation of subsecond time, which resembles a centralized clock, on top of the known distributed timing mechanisms and their readout and integration.
Ingested insecticide to control Aedes aegypti: Developing a novel dried attractive toxic sugar bait device for intra-domiciliary control
Authors: Sippy Rachel , Rivera Galo E. , Sanchez Valeria , Heras Froilán Heras , Morejón Bianca , Ayala Efraín Beltrán , Hikida Robert S. , López-Latorre María A. , Aguirre Alex , Stewart-Ibarra Anna M. , Larsen David A. , Neira Marco
Published: October 2019

Background

Illnesses transmitted by Aedes aegypti (Linnaeus, 1762) such as dengue, chikungunya and Zika comprise a considerable global burden; mosquito control is the primary public health tool to reduce disease transmission. Current interventions are inadequate and insecticide resistance threatens the effectiveness of these options. Dried attractive bait stations (DABS) are a novel mechanism to deliver insecticide to Ae. aegypti. The DABS are a high-contrast 28 inch2 surface coated with dried sugar-boric acid solution. Ae. aegypti are attracted to DABS by visual cues only, and the dried sugar solution elicits an ingestion response from Ae. aegypti landing on the surface. The study presents the development of the DABS and tests of their impact on Ae. aegypti mortality in the laboratory and a series of semi-field trials.

Methods

We conducted multiple series of laboratory and semi-field trials to assess the survivability of Ae. aegypti mosquitoes exposed to the DABS. For laboratory experiments we assessed the lethality, the killing mechanism, and the shelf life of the device through controlled experiments. In the semi-field trials, we released laboratory-reared female Ae. aegypti into experimental houses typical of peri-urban tropical communities in South America in three trial series with six replicates each. Laboratory experiments were conducted in Quito, Ecuador, and semi-field experiments were conducted in Machala, Ecuador – an area with abundant wild populations of Ae. aegypti and endemic arboviral transmission.

Results

In the laboratory, complete lethality was observed after 48 hours regardless of physiological status of the mosquito. The killing mechanism was determined to be through ingestion, as the boric acid disrupted the gut of the mosquito. In experimental houses, total mosquito mortality was greater in the treatment house for all series of experiments (p<0.0001).

Conclusions

The DABS devices were effective at killing female Ae. aegypti under a variety of laboratory and semi-field conditions. DABS are a promising intervention for interdomiciliary control of Ae. aegypti and arboviral disease prevention.
The majority of the matrix protein TapA is dispensable for biofilm formation byBacillus subtilis
Authors: Earl Chris , Arnaouteli Sofia , Sukhodub Tetyana , MacPhee Cait E. , Stanley-Wall Nicola R.
Published: October 2019

Biofilm formation is a co-operative behaviour where microbial cells become embedded in an extracellular matrix. This biomolecular matrix plays a key role in the manifestation of the beneficial or detrimental outcome mediated by the collective of cells.Bacillus subtilisis an important bacterium for understanding the general principles of biofilm formation and is a plant growth-promoting organism. The protein components of theB. subtilismatrix include the secreted proteins BslA, which forms a hydrophobic coat over the biofilm, and TasA, which forms protease-resistant fibres needed for structuring. A third protein TapA (forTasAanchoring and assemblyprotein) is needed for biofilm formation and helps TasA fibre formationin vivobut is dispensable for TasA-fibre assemblyin vitro. Here we show that TapA is subjected to proteolytic cleavage in the biofilm and that only the first 57 amino acids of the 253-amino acid protein are required for biofilm architecture. However, through the construction of a strain which lacks all eight extracellular proteases, we show that proteolytic cleavage by these enzymes is not a prerequisite for TapA function. It remains unknown why TapA is synthesized at a full length of 253 amino acids when the first 57 are sufficient for biofilm structuring, but the findings do not exclude the core conserved region of TapA having a second role beyond that of structuring theB. subtilisbiofilm.
Stable and dynamic representations of value in the prefrontal cortex
Authors: Enel Pierre , Wallis Joni , Rich Erin
Published: October 2019

The ability to associate positive and negative outcomes with predictive stimuli allows us to make optimal decisions. These stimulus-value associations are kept up to date by comparing an expected value with the experienced outcome. When a stimulus and its outcome are separated by a delay, the value associated with the stimulus must be held in mind for such comparisons to be possible, however little is known about the neural mechanisms that hold value representations online across delays. Temporarily remembering task-relevant information has been extensively studied in the context of item-specific working memory, and different hypotheses have suggested this ability requires either persistent or transient neuronal activity, with stable or dynamic representations respectively. To test these different hypotheses in the context of value representations, we recorded the spiking activity of neurons in the orbitofrontal and anterior cingulate cortex of two monkeys performing a task in which visual cues predicted a reward delivered after a short delay. We found that features of all hypotheses were simultaneously present in prefrontal activity and therefore no single hypothesis was exclusively supported. Instead, we report mixed dynamics that support robust, time invariant value representations while also encoding the information in a temporally specific manner. We suggest that this hybrid coding is important for optimal behavior and might be a critical mechanism supporting flexible cognitive abilities.
A Machine Learning Approach to Predict Hypotensive Events in ICU Settings
Authors: Moghadam Mina Chookhachizadeh , Masoumi Ehsan , Bagherzadeh Nader , Ramsingh Davinder , Li Guann-Pyng , Kain Zeev N
Published: October 2019

Purpose

Predicting hypotension well in advance provides physicians with enough time to respond with proper therapeutic measures. However, the real-time prediction of hypotension with high positive predictive value (PPV) is a challenge due to the dynamic changes in patients’ physiological status under the drug administration which is limiting the amount of useful data available for the algorithm.

Methods

To mimic real-time monitoring, we developed a machine learning algorithm that uses most of the available data points from patients’ record to train and test the algorithm. The algorithm predicts hypotension up to 30 minutes in advance based on only 5 minutes of patient’s physiological history. A novel evaluation method is proposed to assess the algorithm performance as a function of time at every timestamp within 30 minutes prior to hypotension. This evaluation approach provides statistical tools to find the best possible prediction window.

Results

During 181,000 minutes of monitoring of about 400 patients, the algorithm demonstrated 94% accuracy, 85% sensitivity and 96% specificity in predicting hypotension within 30 minutes of the events. A high PPV of 81% obtained and the algorithm predicted 80% of the events 25 minutes prior to their onsets. It was shown that choosing a classification threshold that maximizes the F1 score during the training phase contributes to a high PPV and sensitivity.

Conclusion

This study reveals the promising potential of the machine learning algorithms in real-time prediction of hypotensive events in ICU setting based on short-term physiological history.
Evolutionary branching in distorted trait spaces
Authors: Ito Hiroshi C. , Sasaki Akira
Published: October 2019

Biological communities are thought to have been evolving in trait spaces that are not only multi-dimensional, but also distorted in a sense that mutational covariance matrices among traits depend on the parental phenotypes of mutants. Such a distortion may affect diversifying evolution as well as directional evolution. In adaptive dynamics theory, diversifying evolution through ecological interaction is called evolutionary branching. This study analytically develops conditions for evolutionary branching in distorted trait spaces of arbitrary dimensions, by a local nonlinear coordinate transformation so that the mutational covariance matrix becomes locally constant in the neighborhood of a focal point. The developed evolutionary branching conditions can be affected by the distortion when mutational step sizes have significant magnitude difference among directions, i.e., the eigenvalues of the mutational covariance matrix have significant magnitude difference.
A decoy heterotrimeric Gα protein has substantially reduced nucleotide binding but retains nucleotide-independent interactions with its cognate RGS protein and Gβγ dimer
Authors: Lou Fei , Abramyan Tigran M. , Jia Haiyan , Tropsha Alexander , Jones Alan M.
Published: October 2019

Plants uniquely have a family of proteins called extra-large G proteins (XLG) that share homology in their C-terminal half with the canonical Gα subunits; we carefully detail here that Arabidopsis XLG2 lacks critical residues requisite for nucleotide binding and hydrolysis which is consistent with our quantitative analyses. Based on microscale thermophoresis, Arabidopsis XLG2 binds GTPγS with an affinity 100-1000 times lower than that to canonical Gα subunits. This means that given the concentration range of guanine nucleotide in plant cells, XLG2 is not likely bound by GTPin vivo. Homology modeling and molecular dynamics simulations provide a plausible mechanism for the poor nucleotide binding affinity of XLG2. Simulations indicate substantially stronger salt bridge networks formed by several key amino-acid residues of AtGPA1 which are either misplaced or missing in XLG2. These residues in AtGPA1 not only maintain the overall shape and integrity of the apoprotein cavity but also increase the frequency of favorable nucleotide-protein interactions in the nucleotide-bound state. Despite this loss of nucleotide dependency, XLG2 binds the RGS domain of AtRGS1 with an affinity similar to the Arabidopsis AtGPA1 in its apo-state and about 2 times lower than AtGPA1 in its transition state. In addition, XLG2 binds the Gβγ dimer with an affinity similar to that of AtGPA1. XLG2 likely acts as a dominant negative Gα protein to block G protein signaling. We propose that XLG2, independent of guanine nucleotide binding, regulates the active state of the canonical G protein pathway directly by sequestering Gβγ and indirectly by promoting heterodimer formation.
Establishing the baseline for using plankton as biosensor
Authors: Pastore Vito P. , Zimmermann Thomas , Biswas Sujoy K. , Bianco Simone
Published: October 2019

Plankton is at the bottom of the food chain. Microscopic phytoplankton account for about 50% of all photosynthesis on Earth, corresponding to 50 billion tons of carbon each year, or about 125 billion tonnes of sugar[1]. Plankton is also the food for most species of fish, and therefore it represents the backbone of the aquatic environment. Thus, monitoring plankton is paramount to infer potential dangerous changes to the ecosystem. In this work we use a collection of plankton species extracted from a large dataset of images from the Woods Hole Oceanographic Institution (WHOI), to establish a basic set of morphological features for supporting the use of plankton as a biosensor. Using a perturbation detection approach, we show that it is possible to detect deviation from the average space of features for each species of plankton microorganisms, that we propose could be related to environmental threat or perturbations. Such an approach can open the way for the development of an automatic Artificial Intelligence (AI) based system for using plankton as biosensor.
Calcium Imaging Reveals Host-Graft Synaptic Network Formation in Spinal Cord Injury
Authors: Ceto S , Sekiguchi KJ , Takashima Y , Nimmerjahn A , Tuszynski MH
Published: October 2019

Neural stem/progenitor cell grafts integrate into sites of spinal cord injury (SCI) and form anatomical and electrophysiological neuronal relays across lesions. To determine how grafts become synaptically organized and connect with host systems, we performed calcium imaging of neural progenitor cell grafts within sites of SCI, using both in vivo imaging and spinal cord slices. Stem cell grafts organize into localized synaptic networks that are spontaneously active. Following optogenetic stimulation of host corticospinal tract axons regenerating into grafts, distinct and segregated neuronal networks respond throughout the graft. Moreover, optogenetic stimulation of graft axons extending out from the lesion into the denervated spinal cord also trigger responses in local host neuronal networks. In vivo imaging reveals that behavioral stimulation of host elicits focal synaptic responses within grafts. Thus, remarkably, neural progenitor cell grafts form functional synaptic subnetworks in patterns paralleling the normal spinal cord.
Integration of locomotion and auditory signals in the mouse inferior colliculus
Authors: Yang Yoonsun , Lee Joonyeol , Kim Gunsoo
Published: October 2019

The inferior colliculus (IC) is the major midbrain auditory integration center, where virtually all ascending auditory inputs converge. Although the IC has been extensively studied for sound processing, little is known about the neural activity of the IC in moving subjects, as frequently happens in natural hearing conditions. Here we show, by recording the IC neural activity in walking mice, the activity of IC neurons is strongly modulated by locomotion in the absence of sound stimulus presentation. Similar modulation was also found in deafened mice, demonstrating that IC neurons receive non-auditory, locomotion-related neural signals. Sound-evoked activity was attenuated during locomotion, and the attenuation increased frequency selectivity across the population, while maintaining preferred frequencies. Our results suggest that during behavior, integrating movement-related and auditory information is an essential aspect of sound processing in the IC.
Perineuronal nets stabilize the grid cell network
Authors: Christensen Ane Charlotte , Lensjø Kristian Kinden , Lepperød Mikkel Elle , Dragly Svenn-Arne , Sutterud Halvard , Blackstad Jan Sigurd , Fyhn Marianne , Hafting Torkel
Published: October 2019

Grid cells are part of a widespread network that supports navigation and spatial memory. Stable grid patterns appear late in development, in concert with extracellular matrix aggregates termed perineuronal nets (PNNs) that condense around inhibitory neurons. To reveal the relationship between stable spatial representations and the presence of PNNs we recorded from populations of neurons in adult rats. We show that removal of PNNs leads to lower inhibitory spiking activity, and reduces grid cells’ ability to create stable representations of a novel environment. Furthermore, in animals with disrupted PNNs, exposure to a novel arena corrupted the spatiotemporal relationships within grid cell modules, and the stored representations of a familiar arena. Finally, we show that PNN removal in entorhinal cortex distorted spatial representations in downstream hippocampal neurons. Together this work suggests that PNNs provide a key stabilizing element for the grid cell network.
A municipal database from the 2011 Spanish census
Authors: Goerlich Francisco J.
Published: October 2019

Purpose

The paper aims to describe the process to obtain a complete municipal database from the 2011 Spanish Census information. By complete, the authors mean variables for the full sample of the 8,116 municipalities as of the census reference date. In addition, the database should be consistent with the public census information released by the National Statistical Institute: microdata and customized tables.

Design/methodology/approach

The authors use mainly small area demographic and synthetic estimators that are reconciled using biproportional adjustment (iterative proportional fitting), when needed.

Findings

As a result, the authors obtain a complete and consistent municipal database composing 55 variables related to socio-demographic characteristics of persons.

Originality/value

The provision of a complete and consistent municipal database, available for download, which is absent in the original 2011 Spanish Census.