bluuebunny/crossref_metadata_2025 huggingface dataset:
Persons With Dementia and Their Caregivers' Perceptions About Occupational Therapy and Telehealth
Authors: Nissen Ranelle M. , Hersch Gayle , Tietze Mari , Chang Pei-Fen J.
Published: October 2018

Occupational therapy (OT) services provided in the home to a person with dementia can decrease caregiver burden by targeting home modifications, functional performance, and safety. One method to deliver these services is through telehealth. The use of telehealth is expanding rapidly, but there is a current lack of evidence to support the use of telehealth to deliver OT services to persons with dementia. The purpose of this study was to identify the perceptions of persons with dementia and their caregivers about the use of telehealth to receive OT services. A qualitative descriptive design was used. Results provided themes in three domains: dementia journey, skills for technology use, and perceptions of OT. Each participant identified a unique journey through awareness, challenges, and adaptive strategies as they adjusted to a life with dementia. The skills for technology focused on current usage and perceptions about technology. Participants had limited knowledge of OT but did appreciate the role it has in dementia care. The themes identified in the study provide support for further exploration of the use of telehealth in OT for persons with dementia and their caregivers.
Civilian Nurses' Knowledge, Confidence, and Comfort Caring for Military Veterans
Authors: Elliott Brenda
Published: October 2018

More than 20 million Veterans currently live in the United States, representing World War II, Korea, Vietnam, Iraq, and Afghanistan war eras, as well as many who served during peacetime. Little is known regarding what home care nurses know about the unique healthcare needs of this population. Using Purnell's Model for Cultural Competence, a mixed-methods study was designed to examine home care nurse's knowledge, comfort, and confidence in caring for active military, Veterans and their families. This article provides the data from a national survey of 102 home care nurses. Findings suggest that civilian home care nurses have limited experience working with active military but work with Veterans at least monthly, if not weekly. Nurses were most confident in managing pain and least confident in managing issues related to military sexual trauma. Knowledge of resources available to Veterans, war-specific exposures, and Veteran-specific health issues were the top areas nurses felt less confident in. Continued efforts need to be put in place so that 100% of all patients seeking healthcare are screened for military/Veteran status. In addition, continuing education for nurses needs to include Veteran-specific topics so evidence-based, culturally sensitive care can be provided.
Conceptualization of the Chronic Care Model
Authors: Garland-Baird Lisa , Fraser Kimberly
Published: October 2018

One of the greatest challenges for healthcare systems is the management and prevention of chronic diseases. Wagner's Chronic Care Model aims to transform the daily care of patients with chronic illnesses from acute and reactive to proactive, planned, and population-based. The purpose of this article is to provide a review of the available research relating to the Chronic Care Model and consider the implications for Home Care Case Management practice. A total of 18 research studies (5 qualitative and 13 quantitative) were reviewed. A thematic content analysis approach was used. The findings included three themes: Chronic Care Model and positive chronic illness health behaviors and outcomes; Chronic Care Model and delivery of quality chronic illness care; and the importance of the supportive role of the home care nurse in the role of Home Care Case Management. Gaps and limitations of the Chronic Care Model in relation to Home Care Case Management were identified and discussed in relationship to partnership building and reciprocal trust between patients, family caregivers, and the Home Care Case Manager. Finally, implications for the use of the Chronic Care Model in Home Care Case Manager practice, policy development, and future research were presented.
HIV/AIDS
Authors: Capriotti Teri
Published: October 2018

Human immunodeficiency virus (HIV) infection, once fatal, has become a chronic disease that can be treated and well-managed. Antiretroviral treatment (ART) can result in undetectable levels of HIV in the bloodstream. The risk factors, transmission, diagnosis, treatment, acute HIV infection, potential opportunistic infections, and malignancies should be understood by all those caring for persons living with HIV. Preventive treatment is possible with preexposure and postexposure prophylaxis regimens. Home healthcare providers can assist individuals to adhere to medication regimens, monitor efficacy of treatment, recognize complications of HIV and side effects of ART. Most importantly, they can support, educate, and counsel persons living with HIV and their families.
Native T1 Mapping as an In Vivo Biomarker for the Identification of Higher-Grade Renal Cell Carcinoma
Authors: Adams Lisa C. , Ralla Bernhard , Jurmeister Philipp , Bressem Keno K. , Fahlenkamp Ute L. , Hamm Bernd , Busch Jonas , Makowski Marcus R.
Published: October 2018

Objectives

The aims of this study were to identify higher-grade clear cell renal cell carcinoma (cRCC) with native T1 mapping and to histologically correlate the results with the collagen volume fraction.

Materials and Methods

For this institutional review board–approved, single-center prospective study, 68 consecutive patients received abdominal magnetic resonance imaging scans at 1.5 T between January 2017 and July 2018, using a Modified Look-Locker Inversion Recovery (MOLLI) sequence. Thirty patients with cRCC (20 men; mean age, 61.9 ± 13.1 years) who underwent partial or radical nephrectomy and histological grading according to the International Society of Urological Pathology (ISUP) classification and a separate healthy cohort of 30 individuals without renal malignancies or complex cysts (16 men; mean age, 59.7 ± 14.6 years) met the eligibility criteria. T1 values were quantitatively measured with region of interest measurements in T1 maps. Quantification of the collagen volume fraction was performed on histological sections (picrosirius red staining).

Results

Native T1 values were significantly lower for lower-grade cRCC (ISUP 1 and 2) compared with higher-grade cRCC (ISUP 3 and 4; P < 0.001). A cutoff value of 1101 milliseconds distinguished higher-grade from lower-grade tumors with a sensitivity of 100% (95% confidence interval [CI], 0.69–1.00), a specificity of 85% (95% CI, 0.62–0.97), and an accuracy of 90% (95% CI, 0.73–0.98). Native T1 values were significantly associated with the histological collagen volume fraction (P < 0.05). Furthermore, T1 times in the renal cortex, medulla, and tumor tissue showed an excellent interobserver agreement.

Conclusions

Native T1 mapping could represent an in vivo biomarker for the differentiation of lower- and higher-grade cRCCs, providing incremental diagnostic value beyond qualitative magnetic resonance imaging features.
High mortality in aquatic predators of mosquito larvae caused by exposure to insect repellent
Authors: Almeida Rafael M. , Han Barbara A. , Reisinger Alexander J. , Kagemann Catherine , Rosi Emma J.
Published: October 2018

In the face of mosquito-borne disease outbreaks, effective mosquito control is a primary goal for public health. Insect repellents, containing active compounds such as DEET and picaridin, are a first defence against biting insects. Owing to widespread use and incomplete sewage treatment, these compounds are frequently detected in surface waters, but their effects on aquatic taxa such as mosquito larvae or their naturally occurring aquatic predators are poorly understood. We investigated the effects of environmentally realistic concentrations of commercial products containing DEET and picaridin on survivorship of mosquito larvae, and their potential indirect effects on survival of larval salamanders, a major predator of mosquito larvae. Larval mosquitos were not affected by exposure to repellents containing DEET or picaridin. We found no larval salamander mortality in control and DEET treatments, but mortality rates in picaridin treatments ranged from 45 to 65% after 25 days of exposure. Salamander larvae exposed to repellents containing picaridin began to display tail deformities and impaired development four days after the experiment began. Our findings suggest the possibility that environmentally realistic concentrations of picaridin-containing repellents in surface waters may increase the abundance of adult mosquitos owing to decreased predation pressure.
Native reptiles alter their foraging in the presence of the olfactory cues of invasive mammalian predators
Authors: Webster C. , Massaro M. , Michael D. R. , Bambrick D. , Riley J. L. , Nimmo D. G.
Published: October 2018

Invasive mammalian predators are linked to terrestrial vertebrate extinctions worldwide. Prey naïveté may explain the large impact invasive predators have on native prey; prey may fail to detect and react appropriately to the cues of novel predators, which results in high levels of depredation. In Australia, the feral cat (Felis catus) and the red fox (Vulpes vulpes) are implicated in more than 30 animal extinctions and the naïveté of native prey is often used to explain this high extinction rate. Reptiles are one group of animals that are heavily preyed upon byF. catusandV. vulpes. However, very few studies have examined whether reptiles are naive to their cues. In this study, we examine the ability of two native reptile species (Morethia boulengeriandChristinus marmoratus) to detect and distinguish between the chemical cues of two invasive predators (V. vulpesandF. catus) and three native predators (spotted-tailed quoll,Dasyurus maculatus;dingo,Canis lupus dingo; eastern brown snake,Pseudonaja textilis), as well as two non-predator controls (eastern grey kangaroo,Macropus giganteusand water). We conducted experiments to quantify the effects of predator scents on lizard foraging (the amount of food eaten) during 1 h trials within Y-maze arenas. We found both study species reduced the amount they consumed when exposed to predator scents—both native and invasive—indicating that these species are not naive to invasive predators. An evolved generalized predator-recognition system, rapid evolution or learned behaviour could each explain the lack of naïveté in some native Australian reptiles towards invasive predators.
Long-term biodegradation of aged saline-alkali oily sludge with the addition of bulking agents and microbial agents
Authors: Wang Shijie , Wang Xiang
Published: October 2018

Huge amount of aged oily sludge was generated during the drilling and transportation of crude oil. Sometimes, the sludge exhibited characters of combined pollution, such as saline-alkali oily sludge. Orthogonal experiments of L
16
(4
5
) were conducted to evaluate the long-term effects of total petroleum hydrocarbons (TPH) concentration, microbial agents (Oil Gator and ZL) and bulking agents (peat and wheat bran) on the biodegradation of aged saline-alkali oily sludge. Compared with the control group, the significant improvement in the removal rate of TPH was exhibited with the addition of microbial agents and bulking agents after 231 days of the experimental period. Based on the values of mean range (
R
), it was revealed that the predominant influencing factor of the bioremediation was TPH concentration. After biostimulation and bioaugmentation, the quantity of petroleum hydrocarbon-degrading bacteria in the oily sludge increased by 2–4 orders of magnitude. Furthermore, the bioremediation improved the microbial diversity based on the analysis of PCR-DGGE. It was inferred that the addition of microbial agents and bulking agents reconstructed the microbial ecological niche. The principal component analysis indicated that the differentiation of the microbial community was generated by the biostimulation and bioaugmentation in comparison with the control samples.
Assessing mesophotic coral ecosystems inside and outside a Caribbean marine protected area
Authors: Gress Erika , Arroyo-Gerez Maria J. , Wright Georgina , Andradi-Brown Dominic A.
Published: October 2018

Widespread shallow coral reef loss has led to calls for more holistic approaches to coral reef management, requiring inclusion of ecosystems interacting with shallow coral reefs in management plans. Yet, almost all current reef management is biased towards shallow reefs, and overlooks that coral reefs extend beyond shallow waters to mesophotic coral ecosystems (MCEs; 30–150 m). We present the first detailed quantitative characterization of MCEs off Cozumel, Mexico, on the northern Mesoamerican Reef in the Mexican Caribbean, and provide insights into their general state. We documented MCE biodiversity, and assessed whether MCEs adjacent to a major town and port, where coastal development has caused shallow reef damage, have similar benthic and fish communities to MCEs within a National Park. Our results show that overall MCE communities are similar regardless of protection, though some taxa-specific differences exist in benthic communities between sites within the MPA and areas outside. Regardless of protection and location, and in contrast to shallow reefs, all observed Cozumel MCEs were continuous reefs with the main structural habitat complexity provided by calcareous macroalgae, sponges, gorgonians and black corals. Hard corals were present on MCEs, although at low abundance. We found that 42.5% of fish species recorded on Cozumel could be found on both shallow reefs and MCEs, including 39.6% of commercially valuable fish species. These results suggest that MCEs could play an important role in supporting fish populations. However, regardless of protection and depth, we found few large-body fishes (greater than 500 mm), which were nearly absent at all studied sites. Cozumel MCEs contain diverse benthic and fish assemblages, including commercially valuable fisheries species and ecosystem engineers, such as black corals. Because of their inherent biodiversity and identified threats, MCEs should be incorporated into shallow-reef-focused Cozumel National Park management plan.
Interleukin 6 promotes an
in vitro
mineral deposition by stem cells isolated from human exfoliated deciduous teeth
Authors: Nowwarote Nunthawan , Sukarawan Waleerat , Kanjana Kiattipan , Pavasant Prasit , Fournier Benjamin P. J. , Osathanon Thanaphum
Published: October 2018

Interleukin 6 (IL-6) plays various roles including stem cell regulation. The present study investigated the effect of IL-6 on cell proliferation, colony forming unit ability, stem cell marker expression and differentiation ability in stem cells isolated from human exfoliated deciduous teeth (SHEDs). We reported that the isolated cells from dental pulp tissues for deciduous teeth expressed CD44, CD90 and CD105 but not CD45. These cells were able to differentiate into osteoblasts, adipocytes and neuronal-like cells. IL-6 treatment resulted in the significant increase of
NANOG, SOX2
and
REX1
mRNA expression. However, IL-6 had no effect on cell proliferation and colony forming unit ability. IL-6 did not alter adipogenic and neurogenic differentiation potency. IL-6 supplementation in osteogenic medium led to a significant increase of mineralization. Furthermore, IL-6 upregulated
ALP, ANKH
and
PIT1
mRNA levels. In conclusion, IL-6 participates in the regulation of pluripotent marker expression and is also involved in mineralization process of SHEDs. Hence, IL-6 could be employed as a supplementary substance in culture medium to maintain stemness and to induce osteogenic induction in SHEDs for future regenerative cell therapy.
Vocal behaviour predicts mating success in giant pandas
Authors: Charlton Benjamin D. , Martin-Wintle Meghan S. , Owen Megan A. , Zhang Hemin , Swaisgood Ronald R.
Published: October 2018

Surprisingly little is known about how mammal vocal signals are used to achieve behavioural synchrony in the lead up to copulation. The ability to signal short-term fluctuations in arousal levels and behavioural intention is likely to be particularly important for synchronizing mating behaviour in asocial species, which must overcome their natural avoidance and aggressive tendencies to mate. Here, we examined vocal behaviour during breeding encounters in captive giant pandas (
Ailuropoda melanoleuca
) to gain a greater understanding of how close-range vocal signalling mediates reproduction in this asocial, and conservation-dependent species. Our results revealed that the occurrence of different giant panda vocalizations and acoustic variation within these calls is predictive of successful encounters leading to copulation, as opposed to unsuccessful encounters that do not. In addition, key differences were detected between vocalizations produced during and just prior to copulation. These findings illustrate that vocal exchanges are crucial for achieving behavioural synchrony and signalling intention to mate in giant pandas, and could also provide a valuable tool for breeding programmes, helping conservation managers to assess the likelihood of breeding introductions leading to copulation or potentially injurious failure.
A dynamics and stability framework for avian jumping take-off
Authors: Parslew Ben , Sivalingam Girupakaran , Crowther William
Published: October 2018

Jumping take-off in birds is an explosive behaviour with the goal of providing a rapid transition from ground to airborne locomotion. An effective jump is predicated on the need to maintain dynamic stability through the acceleration phase. The present study concerns understanding how birds retain control of body attitude and trajectory during take-off. Cursory observation suggests that stability is achieved with relatively little cost. However, analysis of the problem shows that the stability margins during jumping are actually very small and that stability considerations play a significant role in the selection of appropriate jumping kinematics. We use theoretical models to understand stability in prehensile take-off (from a perch) and also in non-prehensile take-off (from the ground). The primary instability is tipping, defined as rotation of the centre of gravity about the ground contact point. Tipping occurs when the centre of pressure falls outside the functional foot. A contribution of the paper is the development of graphical tipping stability margins for both centre of gravity location and acceleration angle. We show that the nose-up angular acceleration extends stability bounds forward and is hence helpful in achieving shallow take-offs. The stability margins are used to interrogate simulated take-offs of real birds using published experimental kinematic data from a guinea fowl (ground take-off) and a diamond dove (perch take-off). For the guinea fowl, the initial part of the jump is stable; however, simulations exhibit a stuttering instability not observed experimentally that is probably due to the absence of compliance in the idealized joints. The diamond dove model confirms that the foot provides an active torque reaction during take-off, extending the range of stable jump angles by around 45°.
Prey productivity and predictability drive different axes of life-history variation in carnivorous marsupials
Authors: Collett Rachael A. , Baker Andrew M. , Fisher Diana O.
Published: October 2018

Variation in life-history strategies has usually been characterized as a single fast–slow continuum of life-history variation, in which mean lifespan increases with age at maturity as reproductive output at each breeding event declines. Analyses of plants and animals suggest that strategies of reproductive timing can vary on an independent axis, with iteroparous species at one extreme and semelparous species at the other. Insectivorous marsupials in the Family Dasyuridae have an unusually wide range of life-history strategies on both purported axes. We test and confirm that reproductive output and degree of iteroparity are independent in females across species. Variation in reproductive output per episode is associated with mean annual rainfall, which predicts food availability. Position on the iteroparity-semelparity axis is not associated with annual rainfall, but species in regions of unpredictable rainfall have longer maximum lifespans, more potential reproductive events per year, and longer breeding seasons. We suggest that these two axes of life-history variation arise because reproductive output is limited by overall food availability, and selection for high offspring survival favours concentrated breeding in seasonal environments. Longer lifespans are favoured when reproductive opportunities are dispersed over longer periods in environments with less predictable food schedules.
Competition between strains ofBorrelia afzeliiinside the rodent host and the tick vector
Authors: Genné Dolores , Sarr Anouk , Gomez-Chamorro Andrea , Durand Jonas , Cayol Claire , Rais Olivier , Voordouw Maarten J.
Published: October 2018

Multiple-strain pathogens often establish mixed infections inside the host that result in competition between strains. In vector-borne pathogens, the competitive ability of strains must be measured in both the vertebrate host and the arthropod vector to understand the outcome of competition. Such studies could reveal the existence of trade-offs in competitive ability between different host types. We used the tick-borne bacteriumBorrelia afzeliito test for competition between strains in the rodent host and the tick vector, and to test for a trade-off in competitive ability between these two host types. Mice were infected via tick bite with either one or two strains, and these mice were subsequently used to create ticks with single or mixed infections. Competition in the rodent host reduced strain-specific host-to-tick transmission and competition in the tick vector reduced the abundance of both strains. The strain that was competitively superior in host-to-tick transmission was competitively inferior with respect to bacterial abundance in the tick. This study suggests that in multiple-strain vector-borne pathogens there are trade-offs in competitive ability between the vertebrate host and the arthropod vector. Such trade-offs could play an important role in the coexistence of pathogen strains.
Bands of brothers and in-laws: Waorani warfare, marriage and alliance formation
Authors: Macfarlan Shane J. , Erickson Pamela I. , Yost James , Regalado Jhanira , Jaramillo Lilia , Beckerman Stephen
Published: October 2018

The root of modern human warfare lies in the lethal coalitionary violence of males in small-scale societies. However, there is a paucity of quantitative data concerning the form and function of coalitionary violence in this setting. Debates exist over how lethal coalitions are constituted, as well as the motivations and benefits for males to join such groups. Data from a lowland Amazonian population, the Waorani of Ecuador, illuminate three issues: (i) the degree to which raiding parties are composed of groups of fraternal kin as opposed to strategic alliances of actual or potential affinal kin; (ii) the extent to which individuals use pre-existing affinal ties to motivate others to participate in war or leverage warfare as a mechanism to create such ties; and (iii) the extent to which participation in raiding is driven by rewards associated with future marriage opportunities. Analyses demonstrate that Waorani raiding parties were composed of a mix of males who were potential affines, actual affines and fraternal kin, suggesting that men used pre-existing genetic, lineal and social kin ties for recruiting raid partners and used raiding as a venue to create novel social relationships. Furthermore, analyses demonstrate that males leveraged raiding alliances to achieve marriage opportunities for themselves as well as for their children. Overall, it appears that a complex set of motivations involving individual rewards, kin marriage opportunities, subtle coercion and the assessment of alliance strength promote violent intergroup conflict among the Waorani. These findings illustrate the complex inter-relationships among kin selection, coalition building and mating success in our species.
Transmission strategies in a chemosynthetic symbiosis: detection and quantification of symbionts in host tissues and their environment
Authors: Russell S. L. , McCartney E. , Cavanaugh C. M.
Published: October 2018

Transmission of bacteria vertically through host tissues ensures offspring acquire symbionts; however, horizontal transmission is an effective strategy for many associations and plays a role in some vertically transmitted symbioses. The bivalve
Solemya velum
and its gammaproteobacterial chemosynthetic symbionts exhibit evolutionary evidence of both transmission modes, but the dominant strategy on an ecological time scale is unknown. To address this, a specific primer set was developed and validated for the
S. velum
symbiont using a novel workflow called specific marker design (SMD). Symbionts were quantified in spawned eggs and sediment and seawater samples from
S. velum
habitats with qPCR. Each egg was estimated to contain 50–100 symbiont genomes. By contrast, symbiont DNA was found at low abundance/occurrence in sediment and seawater, often co-occurring with host mitochondrial DNA, obscuring its origin. To ascertain when eggs become infected, histological sections of
S. velum
tissues were labelled for symbiont 16S rRNA via
in situ
hybridization. This revealed symbionts in the ovary walls and mature oocytes, suggesting association in late oogenesis. These data support the hypothesis that
S. velum
symbionts are vertically transmitted every host generation, thus genetic signatures of horizontal transmission are driven by ecologically infrequent events. This knowledge furthers our understanding of vertical and horizontal mode integration and provides insights across animal–bacterial chemosynthetic symbioses.
Optimized ICA-based removal of ocular EEG artifacts from free viewing experiments
Authors: Dimigen Olaf , Berlin Humboldt-Universität zu
Published: October 2018

Combining EEG with eye-tracking is a promising approach to study neural correlates of natural vision, but the resulting recordings are also heavily contaminated by activity of the eye balls, eye lids, and extraocular muscles. While Independent Component Analysis (ICA) is commonly used to suppress these ocular artifacts, its performance under free viewing conditions has not been systematically evaluated and many published findings display residual artifacts. Here I evaluated and optimized ICA-based correction for two tasks with unconstrained eye movements: visual search in images and sentence reading. In a first step, four parameters of the ICA pipeline were systematically varied: the (1) high-pass and (2) low-pass filter applied to the training data, (3) the proportion of training data containing myogenic saccadic spike potentials (SP), and (4) the threshold for eye tracker-based component rejection. In a second step, the eye-tracker was used to objectively quantify correction quality of each ICA solution, both in terms of undercorrection (residual artifacts) and overcorrection (removal of neurogenic activity). As a benchmark, results were compared to those obtained with an alternative spatial filter, Multiple Source Eye Correction (MSEC). With commonly used settings, Infomax ICA not only left artifacts in the data of both tasks, but also distorted neurogenic activity during eye movement-free intervals. However, correction could be drastically improved by training the ICA on optimally filtered data in which SPs were massively overweighted. With optimized procedures, ICA removed virtually all artifacts, including the SP and its associated spectral broadband artifact, with little distortion of neural activity. It also outperformed MSEC in terms of SP correction. Matlab code is provided.

Author Note

I would like to acknowledge Maarten De Schuymer, who conducted early explorations of the effects of high-pass filtering that helped to initiate the current work. I am also grateful to Lisa Spiering for assisting with the MSEC correction and Werner Sommer for providing an excellent working environment. Collection of one of the datasets was supported by a grant from DFG (FG-868-A2). Comments or corrections are highly appreciated.
A new massively parallel nanoball sequencing platform for whole exome research
Authors: Xu Yu , Lin Zhe , Tang Chong , Tang Yujing , Cai Yue , Zhong Hongbin , Wang Xuebin , Zhang Wenwei , Xu Chongjun , Wang Jingjing , Wang Jian , Yang Huanming , Yang Linfeng , Gao Qiang
Published: October 2018

Background:

Whole exome sequencing (WES) has been widely used in human genetics research. BGISEQ-500 is a recently established next-generation sequencing platform. However, the performance of BGISEQ-500 on WES is not well studied. In this study, we evaluated the performance of BGISEQ-500 on WES by side-to-side comparison with Hiseq4000, on wellcharacterized human sample NA12878.

Results:

BGISEQ demonstrated similarly high reproducibility as Hiseq for variation detection. Also, the SNPs from BGISEQ data is highly consistent with Hiseq results (concordance 96.5%∼97%). Variation detection accuracy was subsequently evaluated with data from the genome in a bottle project as the benchmark. Both platforms showed similar sensitivity and precision in SNP detection. While in indel detection, BGISEQ showed slightly higher sensitivity and lower precision. The impact of sequence depth and read length on variation detection accuracy was further analyzed, and showed that variation detection sensitivity still increasing when the sequence depth is larger than 100x, and the impact of read length is minor when using 100x data.

Conclusions:

This study suggested that BGISEQ-500 is a qualified sequencing platform for WES.
Decoding dynamic implicit and explicit representations of facial expressions of emotion from EEG
Authors: Smith Fraser W. , Smith Marie L
Published: October 2018

Faces transmit a wealth of important social signals. While previous studies have elucidated the network of cortical regions important for perception of facial expression, and the associated temporal components such as the P100, N170 and EPN, it is still unclear how task constraints may shape the representation of facial expression (or other face categories) in these networks. In the present experiment, we investigate the neural information available across time about two important face categories (expression and identity) when those categories are either perceived under explicit (e.g. decoding emotion when task is on emotion) or implicit task contexts (e.g. decoding emotion when task is on identity). Decoding of both face categories, across both task contexts, peaked in a 100-200ms time-window post-stimulus (across posterior electrodes). Peak decoding of expression, however, was not affected by task context whereas peak decoding of identity was significantly reduced under implicit processing conditions. In addition, errors in EEG decoding correlated with errors in behavioral categorization under explicit processing for both expression and identity, but only with implicit decoding of expression. Despite these differences, decoding time-courses and the spatial pattern of informative electrodes differed consistently for both tasks across explicit Vs implicit face processing. Finally our results show that information about both face identity and facial expression is available around the N170 time-window on lateral occipito-temporal sites. Taken together, these results reveal differences and commonalities in the processing of face categories under explicit Vs implicit task contexts and suggest that facial expressions are processed to a richer degree even under implicit processing conditions, consistent with prior work indicating the relative automaticity by which emotion is processed. Our work further demonstrates the utility in applying multivariate decoding analyses to EEG for revealing the dynamics of face perception.
Tethered homing gene drives: a new design for spatially restricted population replacement and suppression
Authors: Dhole Sumit , Lloyd Alun L. , Gould Fred
Published: October 2018

Optimism regarding potential epidemiological and conservation applications of modern gene drives is tempered by concern about the potential unintended spread of engineered organisms beyond the target population. In response, several novel gene drive approaches have been proposed that can, under certain conditions, locally alter characteristics of a population. One challenge for these gene drives is the difficulty of achieving high levels of localized population suppression without very large releases in face of gene flow. We present a new gene drive system, Tethered Homing (TH), with improved capacity for localized population alteration, especially for population suppression. The TH drive is based on driving a payload gene using a homing construct that is anchored to a spatially restricted gene drive. We use a proof of principle mathematical model to show the dynamics of a TH drive that uses engineered underdominance as an anchor. This system is composed of a split homing drive and a two-locus engineered underdominance drive linked to one part of the split drive (the Cas endonuclease). In addition to improved localization, the TH system offers the ability to gradually adjust the genetic load in a population after the initial alteration, with minimal additional release effort.
Feasibility of Topological Data Analysis for event-related fMRI
Authors: Ellis Cameron T. , Lesnick Michael , Henselman-Petrusek Gregory , Keller Bryn , Cohen Jonathan D.
Published: October 2018

Recent fMRI research shows that perceptual and cognitive representations are instantiated in high-dimensional multi-voxel patterns in the brain. However, the methods for detecting these representations are limited. Topological Data Analysis (TDA) is a new approach, based on the mathematical field of topology, that can detect unique types of geometric features in patterns of data. Several recent studies have successfully applied TDA to study various forms of neural data; however, to our knowledge, TDA has not been successfully applied to data from event-related fMRI designs. Event-related fMRI is very common but limited in terms of the number of events that can be run within a practical time frame and the effect size that can be expected. Here, we investigate whether persistent homology — a popular TDA tool that identifies topological features in data and quantifies their robustness — can identify known signals given these constraints. We use fmrisim, a Python-based simulator of realistic fMRI data, to assess the plausibility of recovering a simple topological representation under a variety of conditions. Our results suggest that persistent homology can be used under certain circumstances to recover topological structure embedded in realistic fMRI data simulations.
Intraflagellar transport protein 74 is essential for mouse spermatogenesis and male fertility by regulating axonemal microtubule assembly in mice
Authors: Lin Shi , Ting Zhou , Qian Huang , Shiyang Zhang , Wei Li , Ling Zhang , Rex A Hess , Gregory J Pazour , Zhibing Zhang
Published: October 2018

IFT74 is a component of the core intraflagellar transport (IFT) complex, a bidirectional movement of large particles along the axoneme microtubules for cilia formation. In this study, we investigated its role in sperm flagella formation and discovered that mice deficiency in IFT74 in male germ cells were infertile associated with low sperm counts and immotile sperm. The few developed spermatozoa displayed misshaped heads and short tails. Transmission electron microscopy revealed abnormal flagellar axoneme in the seminiferous tubules where sperm are made. Clusters of unassembled microtubules were present in the spermatids. Testicular expression levels of IFT27, IFT57, IFT81, IFT88 and IFT140 were significantly reduced in the mutant mice, with the exception of IFT20 and IFT25. The levels of ODF2 and SPAG16L proteins were also not changed. However, the processed AKAP4 protein, a major component of the fibrous sheath, a unique structure of sperm tail, was significantly reduced. Our study demonstrates that IFT74 is essential for mouse sperm formation, probably through assembly of the core axoneme and fibrous sheath, and highlights a potential genetic factor (IFT74) that contributes to human infertility in men.
Global lysine acetylation in Escherichia coli results from growth conditions that favor acetate fermentation
Authors: Schilling Birgit , Basisty Nathan , Christensen David G. , Sorensen Dylan , Orr James S. , Wolfe Alan J. , Rao Christopher V.
Published: October 2018

Lysine acetylation is thought to provide a mechanism for regulating metabolism in diverse bacteria. Indeed, many studies have shown that the majority of enzymes involved in central metabolism are acetylated and that acetylation can alter enzyme activity. However, the details regarding this regulatory mechanism are still unclear, specifically with regards to the signals that induce lysine acetylation. To better understand this global regulatory mechanism, we profiled changes in lysine acetylation during growth of Escherichia coli on the hexose glucose or the pentose xylose at both high and low sugar concentrations using label-free mass spectrometry. The goal was to see whether lysine acetylation differed during growth on these two different sugars. No significant differences, however, were observed. Rather, the initial sugar concentration was the principal factor governing changes in lysine acetylation, with higher sugar concentrations causing more acetylation. These results suggest that acetylation does not target specific metabolic pathways but rather simply targets accessible lysines, which may or may not alter enzyme activity. They further suggest that lysine acetylation principally results from conditions that favor accumulation of acetyl phosphate, the principal acetate donor in E. coli.

IMPORTANCE

Bacteria alter their metabolism in response to nutrient availability, growth conditions, and environmental stresses. This process is best understood at the level of transcriptional regulation, where many metabolic genes are conditionally expressed in response to diverse cues. However, additional modes of regulations are known to exist. One is lysine acetylation, a post-translational modification known to target many metabolic enzymes. However, unlike transcriptional regulation, little is known about this regulatory mode. We investigated the factors inducing changes in lysine acetylation by comparing growth on glucose and xylose. We found that the specific sugar used for growth did not alter the pattern of acetylation; rather, the principal factor was the amount of sugar, with more sugar yielding more acetylation. These results imply lysine acetylation is a global regulatory mechanism that is not responsive to the specific carbon source per se but rather the accumulation of downstream metabolites.
Human APOBEC3G prevents emergence of infectious endogenous retrovirus in mice
Authors: Treger Rebecca S. , Tokuyama Maria , Dong Huiping , Ross Susan R. , Kong Yong , Iwasaki Akiko
Published: October 2018

Endogenous retroviruses (ERV) are found throughout vertebrate genomes and failure to silence their activation can have deleterious consequences on the host. Introduction of mutations that subsequently prevent transcription of ERV loci is therefore an indispensable cell-intrinsic defense mechanism that maintains the integrity of the host genome. Abundant in vitro and in silico evidence have revealed that APOBEC3 cytidine-deaminases, including human APOBEC3G (hA3G) can potently restrict retrotransposition; yet in vivo data demonstrating such activity is lacking, particularly since no replication competent human ERV has been identified. In mice deficient for Toll-like receptor 7 (TLR7), transcribed ERV loci can recombine and generate infectious ERV. In this study, we show that mice deficient in the only copy of Apobec3 in the genome did not have spontaneous reactivation of ERVs, nor elevated ERV reactivation when crossed to Tlr7-/- mice. In contrast, expression of a human APOBEC3G transgene abrogated emergence of infectious ERV in the Tlr7-/- background. No ERV RNA was detected in the plasma of hA3G+Apobec3-/-Tlr7-/- mice, and infectious ERV virions could not be amplified through co-culture with permissive cells. These data reveal that hA3G can potently restrict active ERV in vivo, and suggest that the expansion of the APOBEC3 locus in primates has helped restrict ERV reactivation in the human genome.

Importance

Although APOBEC3 proteins are known to be important antiviral restriction factors in both mice and humans, their roles in the restriction of endogenous retroviruses (ERV) have been limited to in vitro studies. Here, we report that human APOBEC3G expressed as a transgene in mice prevents the emergence of infectious ERV from endogenous loci. This study reveals that APOBEC3G can powerfully restrict active retrotransposons in vivo and demonstrates how ectopic expression of human factors in transgenic mouse models can be used to investigate host mechanisms that inhibit retrotransposons and reinforce genomic integrity.
SPRTN Protease and Checkpoint Kinase 1 Cross-Activation Loop Safeguards DNA Replication
Authors: Halder Swagata , Torrecilla Ignacio , Burkhalter Martin D. , Popovic Marta , Fielden John , Vaz Bruno , Oehler Judith , Pilger Domenic , Lessel Davor , Wiseman Katherine , Narayan Singh Abhay , Vendrell Iolanda , Fischer Roman , Philipp Melanie , Ramadan Kristijan
Published: October 2018

The SPRTN metalloprotease is essential for DNA-protein crosslink (DPC) repair and DNA replication in vertebrate cells. Cells deficient in SPRTN protease activity exhibit severe DPC-induced replication stress and genome instability, manifesting as premature ageing and liver cancer in humans and mice. Strikingly, SPRTN-deficient cells also show a severe G2/M checkpoint defect and fail to activate a robust checkpoint kinase 1 (CHK1) signalling cascade normally triggered in response to replication stress. Here, we show that SPRTN activates the CHK1 signalling cascade during physiological (steady-state) DNA replication by proteolysis-dependent eviction of CHK1 from chromatin. The N-terminal CHK1 fragments cleaved by SPRTN protease still possess kinase activity and phosphorylate SPRTN. This CHK1-dependent phosphorylation stimulates SPRTN recruitment to chromatin to further promote CHK1 eviction from chromatin, DPC removal and unperturbed DNA replication. Our data suggest that a SPRTN-CHK1 cross-activation loop is essential for steady-state DNA replication and protection from DNA replication stress, a major source of genome instability in diseases that cause premature ageing and cancer. In addition, we disclose a mechanism of CHK1 activation during physiological DNA replication, when long stretches of single stranded (ss) DNA that are induced by genotoxic stress and activate canonical and robust CHK1 signalling are not present.
Bacterial Zombies and Ghosts: Production of Inactivated Gram-Positive and Gram-Negative Species with Preserved Cellular Morphology and Cytoplasmic Content
Authors: Taddese Rahwa , Belzer Clara , Aalvink Steven , de Jonge Marien I. , Nagtegaal Iris D. , Dutilh Bas E. , Boleij Annemarie
Published: October 2018

There are many approaches available to inactivate bacteria, each with a different efficacy, impact on cell integrity, and potential for application in high-throughput. The aim of this study was to compare these approaches and develop a standardized protocol for generation of intact Gram-positive as well as on Gram-negative “bacterial zombies”, i.e. cells that are metabolically dead with retained cellular integrity. Here, we introduce the term “bacterial zombies” in addition to “bacterial ghosts” to differentiate inactivated bacteria with preserved cellular integrity from those with perforated membranes, where DNA and cytoplasmic contents have been released. This differentiation of inactivated bacteria is important if the cell content is the subject of study, or if cell contents in the media may cause unwanted effects in downstream applications. We inactivated eight different bacterial species by treatment with beta-propiolactone, ethanol, formalin, sodium hydroxide, and pasteurization. Inactivation efficacy was determined by culturing, and cell wall integrity assessed by quantifying released DNA and visualization by scanning electron microscopy. Based on these results, we discuss the choice of bacterial inactivation methods, and conclude that beta-propiolactone and ethanol are the most promising approaches for standardized generation of bacterial zombies.

IMPORTANCE

For applications such as vaccination or analyses that are sensitive to bacterial growth, inactivated bacteria are preferred because they simplify the analyses and the interpretation of results. This study compared various bacterial inactivation treatments that maintain cell integrity and may be used in high-throughput. Our results demonstrated that beta-propiolactone and 70% ethanol were the best techniques to achieve these goals.
Excessive ENaC-mediated sodium influx drives NLRP3 inflammasome-dependent autoinflammation in cystic fibrosis
Authors: Scambler Thomas , Jarosz-Griffiths Heledd H. , Lara-Reyna Samuel , Pathak Shelly , Wong Chi , Holbrook Jonathan , Martinon Fabio , Savic Sinisa , Peckham Daniel , McDermott Michael F.
Published: October 2018

Cystic Fibrosis (CF) is caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene and results in defective CFTR-mediated chloride transport, dysregulation of epithelial sodium channels (ENaC) and exaggerated innate immune responses. We tested the hypothesis that upregulation of ENaC drives autoinflammation in this complex monogenic disease.

We show that monocytes from patients with CF exhibit a systemic proinflammatory cytokine signature, with associated anti-inflammatory M2-type macrophage deficiency. Cells harboring CF mutations are hyperresponsive to NLRP3 stimulation, as evidenced by increased IL-18, IL-1β, ASC-specks levels in serum and caspase-1 activity in monocytes, and by increased IL-18 production and caspase-1 activity in human bronchial epithelial cells (HBECs). In both cell types there is an associated shift to glycolytic metabolism with succinate release, in response to increased energy requirements. Inhibition of amiloride-sensitive sodium channels partially reverses the NLRP3-dependent inflammation and metabolic shift in these cells. Overexpression of β-ENaC, in the absence of CFTR dysfunction, increases NLRP3-dependent inflammation, indicating a CFTR-independent ENaC axis in CF pathophysiology. Sodium channel modulation provides an important therapeutic strategy to combat lung inflammation in CF.