Changes In Response Patterns Research Articles

402 Awardee Talk: Stress-Induced Dna Methylation Changes and Their Implications in Livestock Production

Abstract It is well known that pre- and post-natal stressors can impact livestock phenotype and performance. However, less is known about the molecular mechanisms responsible for the changes observed in individuals exposed to stress. A proposed mechanism is epigenetic modifications, such as DNA methylation (DNAm). Epigenetic marks are considered a bridge between the environment and genetics because the marks shift in response to environmental stimuli. Stress induced alterations of DNAm can result in changes in gene expression which could be the driver behind altered phenotype. “Omic” technologies have allowed the study of how DNAm patterns change in response to stressors in livestock species. Stressors such as weaning, transportation, and heat stress have altered DNAm patterns. These changes in methylation patterns have been associated with changes in immune function, growth, and behavior. Prenatal stressors have also modified DNAm patterns within the offspring, with some differences persisting later in life. These stress induced DNAm alterations can be transgenerational, potentially affecting livestock productivity and health over multiple generations. Not all alterations are negative; certain stress-induced modifications could allow animals to adapt better to stressors and changing conditions. These marks may indicate exposure of the animal to stress and the possible long-term effects on productivity. There is potential for using methylation patterns as a noninvasive way to monitor stress levels and assess animal welfare. Understanding how the methylome responds to stressors and how it contributes to performance will be beneficial for future selection decisions. More research is needed to identify management practices that might mitigate the negative impacts of stress induced DNAm changes and how the industry can take advantage of the role DNAm has in adapting to stressors and new environments. The epigenome will likely play a critical role in the livestock industry's future as the climate shifts and consumer demands focus more on animal welfare.

How Do Gene Expression Patterns Change in Response to Osmotic Stresses in Kuruma Shrimp (Marsupenaeus japonicus)?

Euryhaline crustaceans cope with external salinity changes by mechanisms of osmoregulation. In the current study, we first cloned and confirmed the ORF sequences of the ion-transportation-related genes Na+/K+-ATPase α subunit (NKAα), cytoplasmic carbonic anhydrase (CAc), and V-type H+-ATPase G subunit (VHA-G), and water channels of aquaporins (AQP3, AQP4, and AQP11) from kuruma shrimp (Marsupenaeus japonicus). Further tissue expression patterns showed a higher expression of MjAQP4, MjCAc, MjNKAα, and MjVHA-G in the gills, as well as a higher expression of MjAQP3 and MjAQP11 in the intestine and muscle, respectively. Then, qPCR analysis was used to assess the mRNA expression levels of those osmoregulatory genes in both post-larvae and adult shrimp when they were exposed to acute salinity stress or salinity acclimation. The results revealed significantly decreased expression levels of MjAQP3, MjAQP11, MjNKAα, and MjCAc, and higher expression levels of MjAQP4 and MjVHA-G when the post-larvae shrimp were directly subjected to 10‰ or 50‰ salinity. Moreover, similar expression patterns were also observed in the post-larvae shrimp during the accommodation to 10‰ or 50‰ salinity. As to the adult shrimp, significantly higher expression levels of those genes were observed in the gills after exposure to 10‰ salinity, whereas only the expression levels of MjAQP3, MjAQP11, and MjNKAα were up-regulated in the gills at 40‰ salinity. In contrast, the expression of MjVHA-G was significantly decreased at 40‰ salinity. Finally, during the acclimation to 10‰ salinity, the expression levels of MjAQP3, MjAQP11, and MjNKAα were also significantly elevated, while the expression of MjCAc was significantly decreased in the gills. In addition, the expression levels of MjAQP3, MjAQP4, MjCAc, and MjVHA-G were significantly decreased in the gills during the acclimation to 55‰ salinity. The findings of the study suggest that the examined genes are critical for the adaptation of aquatic crustaceans to changing environmental salinity. Our study lays as the foundation for further research on osmoregulation mechanisms in M. japonicus.

Crystallographic preferred orientation (CPO) patterns in uniaxially compressed deuterated ice: quantitative analysis of historical data

AbstractStrain, temperature and strain rate are crucial factors governing the development of crystallographic preferred orientations (CPO) in ice. To better understand how CPO patterns change in response to these variables, we performed quantitative analyses on neutron diffraction data between 2010 and 2019, collected in situ during uniaxial compression experiments on deuterium ice. At strains >10% and temperatures <−10°C, thec-axis pattern switches from a single maximum (‘cluster’) to small circle (‘cone’), both oriented parallel to shortening. The diameter and mean width of the cone pattern decrease as strain and/or strain rate increases. Prismatic axis (aandm) patterns are characterised by great circles parallel to the pole figure margin and may be distinguishable from the patterns in ice deformed under simple shear. While strain has the main influence on the degree of preferred orientation (or CPO ‘strength’), both temperature and strain rate have minor influences, which limits the extent to which CPOs can be used to measure strain. As cluster patterns can be observed in thec-axes of ice deformed under both pure and simple shear settings, this may complicate interpretations of flow geometry in terrestrial ice unless the prismatic axis patterns are also considered.

RASCH MODELLING TO EVALUATE REASONING DIFFICULTIES, CHANGES OF RESPONSES, AND ITEM MISCONCEPTION PATTERN OF HYDROLYSIS

This study evaluates the difficulties in concept reasoning, changes in response patterns, and item misconception hydrolysis patterns using Rasch modeling. Data were collected through the development of 30 distractor-based diagnostic test items, measuring ten levels of conceptual reasoning ability in three types of salt hydrolysis compounds: 〖〖Na〗_5 P〗_3 O_10, NaOCl and 〖〖(NH〗_4)〗_2 〖SO〗_4. These 30 written test items were completed by 849 students in Gorontalo, Indonesia. The findings show empirical evidence of the reliability and validity of the measurement. Further analysis found that the students’ reasoning difficulty levels of the concept of saline solutions were varied; the calculation of saline solution’s pH level is the most difficult construct to reason. In particular items, changes in response patterns were found; the misconception curve showed a declining trend and disappeared along with the increase of comprehension along the spectrum of students’ abilities. The item misconceptions pattern was found repeatedly in similar items. This finding strengthens the conclusion that resistant misconceptions potentially tend to cause students' conceptual reasoning difficulties and are difficult to diagnose in conventional ways. This study contributes to developing ways of diagnosing resistant misconceptions and being a reference for teachers and researchers in evaluating students' chemical conceptual reasoning difficulties based on Rasch modeling. Keywords: reasoning difficulties, hydrolysis, misconception, Rasch model.

Auditory response patterns of mouse primary auditory cortex to sound stimuli

To investigate the auditory response patterns of mouse primary auditory cortex (A1) neurons. In vivo cell-attached recordings and neural network modeling were performed to detect the changes in response patterns of A1 neurons of awake C57BL/6J mice to sound stimulation with varying lengths. A1 neuron signals were recorded for 216 neurons in 20 awake mice using a target sound stimulation sequence, and the classification and response characteristics of A1 neuron response patterns were examined using post-stimulus spike time histograms. To simulate the diversity of the A1 neuron response patterns, an A1 neuron model was established based on the Wilson-Cowan model and integral-firing model. The neuron connection weight parameters in the model were calculated by examining the micro loop structure of the pyramidal neurons, parvalbumin neurons, and somatostatin neurons in the A1 region, and the A1 neural network information coding model was constructed. The Onset response neurons only had fast spike response within 10 to 40 ms after the beginning of noise stimulation (122 neurons). The Sustained response neurons had spike response continuously during the noise stimulation (26 neurons). The On-off response neurons had fast spike response after the beginning and the end of noise stimulation (40 neurons). The Offset response neurons only had fast spike response within 10 to 40 ms after the end of noise stimulation (22 neurons). In the neural network model, the Onset peak neural activities of A1 pyramidal neurons, parvalbumin neurons, and somatostatin neurons were 0.7483, 0.5236 and 0.9427, respectively, and their response half peak widths were 18.5 ms, 12 ms and 31 ms during the 100 ms noise stimulation, respectively. By changing the feedforward excitation and synaptic inhibition time constants in the model, the neurons generated numerous different types of spike train. The auditory response of mouse A1 neurons to sound stimuli shows mainly the Onset, Sustained, On-off, and Offset response patterns.

Intraoperative opioid and analgesic adjuvant administration practice patterns following implementation of an enhanced recovery after surgery protocol for laparoscopic donor nephrectomy

Study objectiveThe primary aim of this study is to understand how intraoperative medication administration patterns change in response to ERAS® protocol implementation for patients who underwent laparoscopic donor nephrectomy. DesignSingle-center, retrospective analysis of laparoscopic donor nephrectomy patients. SettingLarge tertiary academic medical center. PatientsWe divided all cases of laparoscopic donor nephrectomies (n = 929) over seven years into three approximately equal time periods: Pre-ERAS 1 (n = 317), Pre-ERAS 2 (n = 297) and Post-ERAS (n = 315). MeasurementsWe examined patient demographics, intraoperative opioid and non-opioid pain adjuvant administration, Post Anesthesia Recovery Unit (PACU) pain scores and opioid use as well as PACU and hospital lengths of stay (LOS). Main resultsSegmented regression analysis of interrupted time series was utilized to evaluate the association of ERAS protocol implementation with the amount of intraoperative opioid and non-opioid pain adjuvant use. In adherence to our institutional ERAS protocol, there was a significant reduction in intraoperative fentanyl use after ERAS protocol of −70.2μg (95% CI -106.0, −34.2, p < 0.001) and a significant increase in intraoperative hydromorphone use of 0.47 mg (95% CI 0.284, 0.655, p < 0.001). However, in contrary to our ERAS protocol, we found no significant change in odds of receiving IV acetaminophen OR 1.31 (95% CI 0.450, 3.76, p = 0.613) or IV ketorolac OR 1.65 (95% CI 0.804, 3.41, p = 0.172) after ERAS protocol implementation. We found a significant reduction in PACU opioid use of −9.68 Morphine Milligram Equivalents (MME) (95% CI -17.1, −2.31, p = 0.010) but no significant change in PACU initial pain score, PACU LOS and hospital LOS. ConclusionsWe examined intraoperative practice pattern changes by anesthesiologists in response to ERAS protocol implementation for laparoscopic donor nephrectomies. Our results suggest that there was a variable uptake of recommendations from ERAS protocol. While ERAS protocols are often studied as a bundle of best practice recommendations, understanding the variability of provider adherence represents an important future research direction for the ERAS initiative.

Small Prey Animal Habitat Use in Landscapes of Fear: Effects of Predator Presence and Human Activity Along an Urban Disturbance Gradient

Human activity can impose additional stressors to wildlife, both directly and indirectly, including through the introduction of predators and influences on native predators. As urban and adjacent environments are becoming increasingly valuable habitat for wildlife, it is important to understand how susceptible taxa, like small prey animals, persist in urban environments under such additional stressors. Here, in order to determine how small prey animals’ foraging patterns change in response to habitat components and distances to predators and human disturbances, we used filmed giving-up density (GUD) trials under natural conditions along an urban disturbance gradient. We then ran further GUD trials with the addition of experimentally introduced stressors of: the odors of domestic cat (Felis catus)/red fox (Vulpes vulpes) as predator cues, light and sound as human disturbance cues, and their combinations. Small mammals were mostly observed foraging in the GUD trials, and to a lesser degree birds. Animals responded to proximity to predators and human disturbances when foraging under natural conditions, and used habitat components differently based on these distances. Along the urban disturbance gradient situation-specific responses were evident and differed under natural conditions compared to additional stressor conditions. The combined predator with human disturbance treatments resulted in responses of higher perceived risk at environments further from houses. Animals at the urban-edge environment foraged more across the whole site under the additional stressor conditions, but under natural conditions perceived less risk when foraging near predators and further from human disturbance (houses). Contrastingly, at the environments further from houses, foraging near human disturbance (paths/roads) when close to a predator was perceived as lower risk, but when foraging under introduced stressor conditions these disturbances were perceived as high risk. We propose that sensory and behavioral mechanisms, and stress exposure best explain our findings. Our results indicate that habitat components could be managed to reduce the impacts of high predation pressure and human activity in disturbed environments.

Childhood Asthma and Mitochondrial Biomarkers for Exposure-Related Outcomes (CAMERO) study: Time-related Changes in Mitochondrial DNA Copy Number

Air pollution and allergen exposure leads to reactive oxygen species production, causing DNA damage and mitochondrial metabolic activity changes. The Childhood Asthma and Mitochondrial Biomarkers for Exposure Related Outcomes (CAMERO) study hypothesizes that mitochondrial DNA (mtDNA) copy number and methylation patterns change in response to environmental exposures. We hypothesize that changes in biomarkers are associated with disease activity among asthmatic children.

Mating and ejaculate allocation pattern in the kelp crab Taliepus dentatus (Decapoda: Epialtidae)

Ejaculate allocation patterns vary widely among species and often depend on characteristics of the individual. However, it is poorly known whether ejaculate allocation patterns change in response to distinct ontogenetic stages (i.e., adolescent vs. adult). The present study aims to describe the mating process and test variations in ejaculate allocation in response to the ontogenetic stage of the Chilean kelp crab Taliepus dentatus (H. Milne Edwards, 1834). Mating consists of the following sequence: (1) pre-copulatory guarding (i.e., male grasping female and/or caging female between legs), (2) copulation in sternum-to-sternum position, and (3) post-copulatory guarding (i.e., male grasping female or carrying her around by the chelae). The mating behavior and ejaculate allocation pattern differed between the two contrasting male ontogenetic stages. Adolescent males generally delivered less ejaculate in repeated short copulations and adult males transferred more ejaculate in a single extended copulation. Ejaculate allocation in adolescents was dependent on female size, but not so in adults. Variation in the ejaculate allocation pattern may be common in species with contrasting male ontogenetic stages, where less competitive males (i.e., adolescents) economize their limited seminal reserves. Conversely, adults which have a greater capacity to produce seminal material (fluids + spermatozoa) may invest greater quantities of seminal material.

Differential Impacts of Repeated Sampling on Odor Representations by Genetically-Defined Mitral and Tufted Cell Subpopulations in the Mouse Olfactory Bulb.

Sniffing, the active control of breathing beyond passive respiration, is used by mammals to modulate olfactory sampling. Sniffing allows animals to make odor-guided decisions within ∼200 ms, but animals routinely engage in bouts of high-frequency sniffing spanning several seconds; the impact of such repeated odorant sampling on odor representations remains unclear. We investigated this question in the mouse olfactory bulb (OB), where mitral and tufted cells (MTCs) form parallel output streams of odor information processing. To test the impact of repeated odorant sampling on MTC responses, we used two-photon imaging in anesthetized male and female mice to record activation of MTCs while precisely varying inhalation frequency. A combination of genetic targeting and viral expression of GCaMP6 reporters allowed us to access mitral cell (MC) and superficial tufted cell (sTC) subpopulations separately. We found that repeated odorant sampling differentially affected responses in MCs and sTCs, with MCs showing more diversity than sTCs over the same time period. Impacts of repeated sampling among MCs included both increases and decreases in excitation, as well as changes in response polarity. Response patterns across simultaneously-imaged MCs reformatted over time, with representations of different odorants becoming more distinct. Individual MCs responded differentially to changes in inhalation frequency, whereas sTC responses were more uniform over time and across frequency. Our results support the idea that MCs and TCs comprise functionally distinct pathways for odor information processing, and suggest that the reformatting of MC odor representations by high-frequency sniffing may serve to enhance the discrimination of similar odors.SIGNIFICANCE STATEMENT Repeated sampling of odorants during high-frequency respiration (sniffing) is a hallmark of active odorant sampling by mammals; however, the adaptive function of this behavior remains unclear. We found distinct effects of repeated sampling on odor representations carried by the two main output channels from the mouse olfactory bulb (OB), mitral and tufted cells (MTCs). Mitral cells (MCs) showed more diverse changes in response patterns over time as compared with tufted cells (TCs), leading to odorant representations that were more distinct after repeated sampling. These results support the idea that MTCs contribute different aspects to encoding odor information, and they indicate that MCs (but not TCs) may play a primary role in the modulation of olfactory processing by sampling behavior.

Complex habitat drives mammal communities in a flammable landscape

In flammable ecosystems biodiversity can be influenced by multiple drivers, and conservation management requires knowledge of their relative influence. For example, land managers often manipulate fire regimes to increase environmental heterogeneity and promote biodiversity. However, the influence of fire relative to other drivers of biodiversity is often unknown. In this study, we used a temporally replicated dataset to (a) examine the effect of climate, topography, time since fire and habitat structure on mammal alpha- and beta-diversity and (b) assess the consistency of these responses through time. We surveyed ground-dwelling mammals within the Otway Ranges of Australia over four periods between 2010 and 2017. Alpha- and beta-diversity were most strongly influenced by habitat complexity. Alpha-diversity showed a strong positive relationship with habitat complexity, while there was a constant change in beta-diversity along the habitat complexity gradient. The remaining drivers, particularly time since fire, had relatively low influence. Alpha- and beta-diversity were often influenced by different environmental variables, emphasising the value of assessing multiple levels of species diversity. Finally, each survey period predicted the observed data in other years poorly, reflecting temporal change in response patterns, and demonstrating multiple years of data may be needed to characterise the response of species diversity to potential drivers. Overall, our results show environmental variables – particularly habitat structure – are more influential than time since fire in driving species diversity. Land managers seeking to manage species diversity may do so indirectly, through the influence of fire on habitat complexity. However, to do so effectively requires greater understanding of how fire interacts with other factors to influence floristics and vegetation recovery.

Dynamic effects of habituation and novelty detection on newborn event-related potentials

Newborns habituate to repeated auditory stimuli, and discriminate syllables, generating opportunities for early language learning. This study investigated trial-by-trial changes in newborn electrophysiological responses to auditory speech syllables as an index of habituation and novelty detection. Auditory event-related potentials (ERPs) were recorded from 16 term newborn infants, aged 1–3 days, in response to monosyllabic speech syllables presented during habituation and novelty detection tasks. Multilevel models demonstrated that newborns habituated to repeated auditory syllables, as ERP amplitude attenuated for a late-latency component over successive trials. Subsequently, during the novelty detection task, early- and late-latency component amplitudes decreased over successive trials for novel syllables only, indicating encoding of the novel speech syllable. We conclude that newborns dynamically encoded novel syllables over relatively short time periods, as indicated by a systematic change in response patterns with increased exposure. These results have important implications for understanding early precursors of learning and memory in newborns.

Petunia- and Arabidopsis-Specific Root Microbiota Responses to Phosphate Supplementation

Phosphorus (P) is a limiting element for plant growth. Several root microbes, including arbuscular mycorrhizal fungi (AMF), have the capacity to improve plant nutrition and their abundance is known to depend on P fertility. However, how complex root-associated bacterial and fungal communities respond to various levels of P supplementation remains ill-defined. Here we investigated the responses of the root-associated bacteria and fungi to varying levels of P supply using 16S rRNA gene and internal transcribed spacer amplicon sequencing. We grew Petunia, which forms symbiosis with AMF, and the nonmycorrhizal model species Arabidopsis as a control in a soil that is limiting in plant-available P and we then supplemented the plants with complete fertilizer solutions that varied only in their phosphate concentrations. We searched for microbes, whose abundances varied by P fertilization, tested whether a core microbiota responding to the P treatments could be identified and asked whether bacterial and fungal co-occurrence patterns change in response to the varying P levels. Root microbiota composition varied substantially in response to the varying P application. A core microbiota was not identified as different bacterial and fungal groups responded to low-P conditions in Arabidopsis and Petunia. Microbes with P-dependent abundance patterns included Mortierellomycotina in Arabidopsis, while in Petunia, they included AMF and their symbiotic endobacteria. Of note, the P-dependent root colonization by AMF was reliably quantified by sequencing. The fact that the root microbiotas of the two plant species responded differently to low-P conditions suggests that plant species specificity would need to be considered for the eventual development of microbial products that improve plant P nutrition. [Formula: see text]Copyright © 2019 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

The effects of time frames on self-report.

BackgroundThe degree to which episodic and semantic memory processes contribute to retrospective self-reports have been shown to depend on the length of reporting period. Robinson and Clore (2002) argued that when the amount of accessible detail decreases due to longer reporting periods, an episodic retrieval strategy is abandoned in favor of a semantic retrieval strategy. The current study further examines this shift between retrieval strategies by conceptually replicating the model of Robinson and Clore (2002) for both emotions and symptoms and by attempting to estimate the exact moment of the theorized shift.MethodA sample of 469 adults reported the extent to which they experienced 8 states (excited, happy, calm, sad, anxious, angry, pain, stress) over 12 time frames (right now to in general). A series of curvilinear and piecewise linear multilevel growth models were used to examine the pattern of response times and response levels (i.e., rated intensity on a 1–5 scale) across the different time frames.ResultsReplicating previous results, both response times and response levels increased with longer time frames. In contrast to prior work, no consistent evidence was found for a change in response patterns that would suggest a shift in retrieval strategies (i.e., a flattening or decrease of the slope for longer time frames). The relationship between the time frames and response times/levels was similar for emotions and symptoms.ConclusionsAlthough the current study showed a pronounced effect of time frame on response times and response levels, it did not replicate prior work that suggested a shift from episodic to semantic memory as time frame duration increased. This indicates that even for longer time frames individuals might attempt to retrieve episodic information to provide a response. We suggest that studies relying on self-report should use the same well-defined time frames across all self-reported measures.

Precision engineering of targeted nanocarriers.

Since their introduction in 1980, the number of advanced targeted nanocarrier systems has grown considerably. Nanocarriers capable of targeting single receptors, multiple receptors, or multiple epitopes have all been used to enhance delivery efficiency and selectivity. Despite tremendous progress, preclinical studies and clinically translatable nanotechnology remain disconnected. The disconnect in targeting efficacy may stem from poorly-understood factors such as receptor clustering, spatial control of targeting ligands, ligand mobility, and ligand architecture. Further, the relationship between receptor distribution and ligand architecture remains elusive. Traditionally, targeted nanocarriers were engineered assuming a "static" target. However, it is becoming increasingly clear that receptor expression patterns change in response to external stimuli and disease progression. Here, we discuss how cutting-edge technologies will enable a better characterization of the spatiotemporal distribution of membrane receptors and their clustering. We further describe how this will enable the design of new nanocarriers that selectively target the site of disease. Ultimately, we explore how the precision engineering of targeted nanocarriers that adapt to receptor dynamics will have the potential to drive nanotechnology to the forefront of therapy and make targeted nanomedicine a clinical reality. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Biology-Inspired Nanomaterials > Lipid-Based Structures Biology-Inspired Nanomaterials > Protein and Virus-Based Structures.

Impact of SST on heavy rainfall events on eastern Adriatic during SOP1 of HyMeX

The season of late summer and autumn is favourable for intensive precipitation events (IPE) in the central Mediterranean. During that period the sea surface is warm and contributes to warming and moistening of the lowest portion of the atmosphere, particularly the planetary boundary layer (PBL). Adriatic sea is surrounded by mountains and the area often receives substantial amounts of precipitation in short time (24h). The IPEs are a consequence of convection triggered by topography acting on the southerly flow that has brought the unstable air to the coastline. Improvement in prediction of high impact weather events is one of the goals of The Hydrological cycle in the Mediterranean eXperiment (HyMeX). This study examines how precipitation patterns change in response to different SST forcing. We focus on the IPEs that occurred on the eastern Adriatic coast during the first HyMeX Special observing period (SOP1, 6 September to 5 November 2012). The operational forecast model ALADIN uses the same SST as the global meteorological model (ARPEGE from Meteo France), as well as the forecast lateral boundary conditions (LBCs). First we assess the SST used by the operational atmospheric model ALADIN and compare it to the in situ measurements, ROMS ocean model, OSTIA and MUR analyses. Results of this assessment show that SST in the eastern Adriatic was overestimated by up to 10K during HyMeX SOP1 period. Then we examine the sensitivity of 8km and 2km resolution forecasts of IPEs to the changes in the SST during whole SOP1 with special attention to the intensive precipitation event in Rijeka. Forecast runs in both resolutions are performed for the whole SOP1 using different SST fields prescribed at initial time and kept constant during the model forecast. Categorical verification of 24h accumulated precipitation did not show substantial improvement in verification scores when more realistic SST was used. Furthermore, the results show that the impact of introducing improved SST in the analysis on the precipitation forecast varies for different cases. There is generally a larger sensitivity to the SST in high resolution than in the lower one, although the forecast period of the latter is longer.

The Impact of Glottal Configuration on Speech Breathing

The purpose of this study was to examine whether changes in respiratory patterns occurred in response to volitional changes in glottal configuration. Twelve vocally healthy participants read a passage while wearing the Inductotrace respiratory inductive plethysmograph, which measures the excursions of the rib cage and abdomen. Participants read the passage 5 times in a typical speaking voice (baseline phase), 10 times in an experimental voice, which was similar to a breathy vocal quality (experimental phase), and 5 times again in a typical speaking voice (return phase). Kinematic estimates of lung volume (LV) initiation, LV termination, and LV excursion were collected for each speech breath. Participants spoke with larger LV excursions during the experimental phase, characterized by increased LV initiation and decreased LV termination compared with the baseline phase. In response to volitional changes in glottal configuration, healthy individuals spoke with increased LV excursion. They both responded to changes (decreasing LV termination) and planned for more efficient future utterances (increasing LV initiation) during the experimental phase. This study demonstrated that respiratory patterns change in response to changes in glottal configuration; future work will examine these patterns in individuals with voice disorders.

Transcriptional Profiling of the Oral Pathogen Streptococcus mutans in Response to Competence Signaling Peptide XIP.

In the cariogenic Streptococcus mutans, competence development is regulated by the ComRS signaling system comprised of the ComR regulator and the ComS prepeptide to the competence signaling peptide XIP (ComX-inducing peptide). Aside from competence development, XIP signaling has been demonstrated to regulate cell lysis, and recently, the expression of bacteriocins, small antimicrobial peptides used by bacteria to inhibit closely related species. Our study further explores the effect of XIP signaling on the S.mutans transcriptome. RNA sequencing revealed that XIP induction resulted in a global change in gene expression that was consistent with a stress response. An increase in several membrane-bound regulators, including HdrRM and BrsRM, involved in bacteriocin production, and the VicRKX system, involved in acid tolerance and biofilm formation, was observed. Furthermore, global changes in gene expression corresponded to changes observed during the stringent response to amino acid starvation. Effects were also observed on genes involved in sugar transport and carbon catabolite repression and included the levQRST and levDEFG operons. Finally, our work identified a novel heat shock-responsive intergenic region, encoding a small RNA, with a potential role in competence shutoff. IMPORTANCE Genetic competence provides bacteria with an opportunity to increase genetic diversity or acquire novel traits conferring a survival advantage. In the cariogenic pathogen Streptococcus mutans, DNA transformation is regulated by the competence stimulating peptide XIP (ComX-inducing peptide). The present study utilizes high-throughput RNA sequencing (RNAseq) to provide a greater understanding of how global gene expression patterns change in response to XIP. Overall, our work demonstrates that in S.mutans, XIP signaling induces a response that resembles the stringent response to amino acid starvation. We further identify a novel heat shock-responsive intergenic region with a potential role in competence shutoff. Together, our results provide further evidence that multiple stress response mechanisms are linked through the genetic competence signaling pathway in S.mutans.

Multistability and dynamic transitions of intracellular Min protein patterns.

Cells owe their internal organization to self‐organized protein patterns, which originate and adapt to growth and external stimuli via a process that is as complex as it is little understood. Here, we study the emergence, stability, and state transitions of multistable Min protein oscillation patterns in live Escherichia coli bacteria during growth up to defined large dimensions. De novo formation of patterns from homogenous starting conditions is observed and studied both experimentally and in simulations. A new theoretical approach is developed for probing pattern stability under perturbations. Quantitative experiments and simulations show that, once established, Min oscillations tolerate a large degree of intracellular heterogeneity, allowing distinctly different patterns to persist in different cells with the same geometry. Min patterns maintain their axes for hours in experiments, despite imperfections, expansion, and changes in cell shape during continuous cell growth. Transitions between multistable Min patterns are found to be rare events induced by strong intracellular perturbations. The instances of multistability studied here are the combined outcome of boundary growth and strongly nonlinear kinetics, which are characteristic of the reaction–diffusion patterns that pervade biology at many scales.

Attendance and nursing patterns of harp seals in the harsh environment of the northwest Atlantic

Harp seals are capital breeders who give birth to single pups and nurse them with fat-rich milk for 12 days on pack ice in the North Atlantic under harsh environmental conditions. Our objective was to examine female attendance and nursing patterns under varying environmental conditions to determine whether these patterns change in response to changing weather conditions. The behaviour of 158 harp seal females and pups off north-eastern Newfoundland was recorded every 3 min during daylight hours. Air and water temperature, and wind speed were recorded at the beginning of each observation session. We constructed GAMM models to examine the importance of these variables in predicting attendance and nursing patterns. The best model for predicting attendance included time of day, air temperature, wind speed, and the interaction between wind and air temperature. The best model for predicting nursing included wind speed, air temperature and time of day. Females were more likely to attend their pups during the afternoon when solar radiation appeared to be high, but reduced attendance during high winds and/or low temperatures. The likelihood of attending females nursing during these poor weather conditions was greater than when conditions were better. Thus, females were less likely to be present when weather conditions were poor but when present, they were more likely to be provisioning their pups. This strategy may help these females defray the thermoregulatory demands on their limited resources while ensuring that their young attain weights that are likely to increase post-weaning survival and hence maternal fitness.