Effects of the In Ovo Administration of L-ascorbic Acid on the Performance and Incidence of Corneal Erosion in Ross 708 Broilers Subjected to Elevated Levels of Atmospheric Ammonia.

Effects of the in ovo injection of various levels of L-ascorbic acid (L-AA) on the performance and corneal erosion incidence in Ross 708 broilers exposed to 50 parts per million (ppm) of atmospheric ammonia (NH3) after hatch were determined. A total of 1440 Ross 708 broiler embryos were randomly assigned to 4 treatments: non-injected (control), 0.85% sterile saline-injected (control), or saline containing 12 or 25 mg of L-AA. At hatch, 12 male chicks were randomly assigned to each of 48 battery cages with 12 replicate cages randomly assigned to each treatment group. All birds were exposed to 50 ppm of NH3 for 35 d and the concentration of NH3 in the battery cage house was recorded every 20 s. Mortality was determined daily, and mean body weight (BW), BW gain (BWG), average daily BW gain (ADG), and feed intake, as well as feed conversion ratio (FCR), were determined weekly. From 0 to 35 d of post-hatch age (doa), six birds from each cage were selected and sampled for eye erosion scoring. Incidences of corneal erosion were significantly higher at 21 and 28 doa in comparison to those at 14 and 35 doa, and at 21 doa, birds in the saline-injected group exhibited a higher incidence of corneal erosion compared to all other treatment groups. The in ovo injection of 12 mg of L-AA increased BWG (p = 0.043) and ADG (p = 0.041), and decreased FCR (p = 0.043) from 0 to 28 doa in comparison to saline-injected controls. In conclusion the in ovo administration of 12 mg of L-AA may have the potential to improve the live performance of broilers chronically exposed to high aerial NH3 concentrations, but further study is needed to determine the physiological and immunological factors that may contribute to this improvement.

Comparison of cell viability assessment and visualization of Aspergillus niger biofilm with two fluorescent probe staining methods.

Filamentous fungi are ubiquitous and frequent components of biofilms. A means to visualize them and quantify their viability is essential for understanding their development and disruption. However, quantifying filamentous fungal biofilms poses challenges because, unlike yeasts and bacteria, they are not composed of discrete cells of similar size. This research focused on filamentous fungal biofilms that are representative of those in the built environment. The objective of this study was to develop a rapid method to examine biofilm structure and quantify live (metabolically active/ membrane undamaged) and dead (inactive/ membrane damaged) cells in Aspergillus niger biofilms utilizing a fluorescent probe staining method and confocal laser scanning microscopy (CLSM). For this, we compared two commercially available probe staining kits that have been developed for bacterial and yeast systems. One method utilized the classic cell stain FUN 1 that exhibits orange-red fluorescent intravacuolar structures in metabolically active cells, while dead cells are fluoresced green. The second method utilized a combination of SYTO9 and propidium iodide (PI), and stains cells based on their membrane morphology. SYTO9 is a green fluorescent stain with the capacity to penetrate the living cell walls, and PI is a red fluorescent stain that can only penetrate dead or dying cells with damaged cell membranes. Following staining, the biofilms were imaged using CLSM and biofilm volumes and thickness were quantified using COMSTAT, a computer program that measures biofilm accumulation from digital image stacks. The results were compared to independent measurements of live-dead cell density, as well as a classic cell viability assay-XTT. The data showed that the combination of SYTO9 and PI is optimal for staining filamentous fungal biofilms.

Effects of the In Ovo and Dietary Supplementation of L-Ascorbic Acid on the Growth Performance, Inflammatory Response, and Eye L-Ascorbic Acid Concentrations in Ross 708 Broiler Chickens.

Effects of the dietary and in ovo administration of L-ascorbic acid (L-AA) on the performance, plasma nitric oxide, and eye L-AA concentrations of Ross 708 broilers were investigated. At 17 days of incubation, live embryonated hatching eggs were randomly assigned to a non-injected or sham-injected (100 µL of saline) control group, or a group injected with either 12 or 25 mg of L-AA suspended in 100 µL of saline. Chicks received a commercial diet with or without 200 mg/kg of supplemental L-AA and were randomly assigned to each of 6 replicate floor pens in each in ovo injection-dietary treatment combination. Weekly live performance variables through 14 days of post hatch age (doa) and the eye weights in both sexes at 0, 7, and 14 doa were determined. At 0 and 14 doa, plasma nitric oxide levels and eye L-AA concentrations of one bird of each sex in each pen were determined. Dietary supplemental L-AA decreased feed intake and growth between 0 and 7 doa, but from 8 to 14 doa; all birds fed supplemental L-AA had a lower feed conversion ratio. At 14 doa, male chicks had higher eye L-AA concentrations and lower plasma nitric oxide levels when treated in ovo with 12 mg of L-AA. In conclusion, dietary L-AA may be used to improve feed conversion in the second week of broiler post hatch growth. However, the in ovo administration of 12 mg of L-AA can increase male eye L-AA concentrations and is effective in reducing their general inflammatory response.

Effects of the In Ovo Vaccination of the ts-11 Strain of Mycoplasma gallisepticum in Layer Embryos and Posthatch Chicks.

The transmission of the ts-11 strain of Mycoplasma gallisepticum (MG) vaccine (ts-11MGV) between incubated eggs and between hatchlings that was administrated via in ovo injection, and its subsequent effects on their posthatch performance were evaluated. Marek's disease diluent alone (sham-injected) or containing either 3.63 × 101, 102, 103, or 104 cfu of ts-11MGV was manually in ovo-injected into the amnion on 18 days of incubation. Egg residue analysis, percentage incubational egg weight loss, hatchability of viable injected eggs, and hatchling body weight (BW) were assessed. Selected hatchlings from each treatment replicate group were swabbed in the choanal cleft for MG DNA detection. Female chick live performance was also assessed through 21 days of posthatch age. Unexposed control sentinel chicks were allocated to each treatment replicate group to assess horizontal transmission. Birds were later swabbed and bled respectively, for detection of MG DNA and IgM production at 21 days posthatch. In all birds, no MG DNA was detected and SPA tests for IgM were negative. Among all variables, only 0 to 21 day BW gain was significantly affected by treatment and was lower in the 3.63 × 104 ts-11 MGV treatment in comparison to all the other treatments. Because ts-11MGV does not exhibit vertical or horizontal transmission capabilities under commercial conditions, it may not be a good candidate for in ovo injection.

Systematic Review and Regression Modeling of the Effects of Age, Body Size, and Exercise on Cardiovascular Parameters in Healthy Adults.

PURPOSE: Blood pressure, cardiac output, and ventricular volumes correlate to various subject features such as age, body size, and exercise intensity. The purpose of this study is to quantify this correlation through regression modeling. METHODS: We conducted a systematic review to compile reference data of healthy subjects for several cardiovascular parameters and subject features. Regression algorithms used these aggregate data to formulate predictive models for the outputs-systolic and diastolic blood pressure, ventricular volumes, cardiac output, and heart rate-against the features-age, height, weight, and exercise intensity. A simulation-based procedure generated data of virtual subjects to test whether these regression models built using aggregate data can perform well for subject-level predictions and to provide an estimate for the expected error. The blood pressure and heart rate models were also validated using real-world subject-level data. RESULTS: The direction of trends between model outputs and the input subject features in our study agree with those in current literature. CONCLUSION: Although other studies observe exponential predictor-output relations, the linear regression algorithms performed the best for the data in this study. The use of subject-level data and more predictors may provide regression models with higher fidelity. SIGNIFICANCE: Models developed in this study can be useful to clinicians for personalized patient assessment and to researchers for tuning computational models.

Investigating the impacts of crash prediction models on quantifying safety effectiveness of Adaptive Signal Control Systems.

INTRODUCTION: Adaptive Signal Control System (ASCS) can improve both operational and safety benefits at signalized corridors. METHODS: This paper develops a series of models accounting for model forms and possible predictors and implements these models in Empirical Bayes (EB) and Fully Bayesian (FB) frameworks for ASCS safety evaluation studies. Different models are validated in terms of the ability to reduce the potential bias and variance of prediction and improve the safety effectiveness estimation accuracy using real-world crash data from non-ASCS sites. This paper then develops the safety effectiveness of ASCS at six different corridors with a total of 65 signalized intersections with the same type of ASCS, in South Carolina. RESULTS: Validation results show that the FB model that accounts for traffic volume, roadway geometric features, year factor, and spatial effects shows the best performance among all models. The study findings reveal that ASCS reduces crash frequencies in the total crash, fatal and injury crash, and angle crash for most of the intersections. The safety effectiveness of ASCS varies with different intersection features (i.e., AADT at major streets, number of legs at an intersection, the number of through lanes on major streets, the number of access points on minor streets, and the speed limit at major streets). CONCLUSIONS: ASCS is associated with crash reductions, and its safety effects vary with different intersection features. Practical Applications: The findings of this research encourage more ASCS deployments and provide insights into selecting ASCS deployment sites for reducing crashes considering the variation of the safety effectiveness of ASCS.

Assessing the likelihood of secondary crashes on freeways with Adaptive Signal Control System deployed on alternate routes.

INTRODUCTION: Reducing the likelihood of freeway secondary crashes will provide significant safety, operational and environmental benefits. This paper presents a method for assessing the likelihood of freeway secondary crashes with Adaptive Signal Control Systems (ASCS) deployed on alternate routes that are typically used by diverted freeway traffic to avoid any delay or congestion due to a freeway primary crash. METHOD: The method includes four steps: (1) identification of secondary crashes, (2) verification of alternate routes, (3) assessment of the likelihood of secondary crashes for freeways with ASCS deployed on alternate routes and non-ASCS (i.e. pre-timed, semi- or fully-actuated) alternate routes, and (4) investigation of unobserved heterogeneity of the likelihood of freeway secondary crashes. Four freeway sections (i.e., two with ASCS deployed on alternate routes and two non-ASCS alternate routes) in South Carolina are considered. RESULTS AND CONCLUSIONS: Findings from the logistic regression modeling reveal significant reduction in the likelihood of secondary crashes for one freeway section (i.e., Charleston I-26 E) with ASCS deployed on alternate route. Other factors such as rear-end crash, dark or limited light, peak period, and annual average daily traffic contribute to the likelihood of freeway secondary crashes. Furthermore, random-parameter logistic regression model results for Charleston I-26 E reveal that unobserved heterogeneity of ASCS effect exists across the observations and ASCS are associated with the reduction of the likelihood of freeway secondary crashes for 84% of the observations (i.e., primary crashes). Location of the primary crash on the freeway is observed to affect the benefit of ASCS toward freeway secondary crash reduction as the primary crash's location determines how many upstream freeway vehicles will be able to take the alternate route. Practical Applications: Based on the findings, it is recommended that the South Carolina Department of Transportation (SCDOT) considers deploying ASCS on alternate routes parallel to freeway sections where high percentages of secondary crashes are found.

Predictive Models for Pulmonary Artery Size in Fontan Patients.

We developed models of pulmonary artery (PA) size in Fontan patients as a function of age and body surface area (BSA) using linear regression and breakpoint analyses based on data from 43 Fontan patients divided into two groups: the extracardiac conduit (ECC) group (n = 24) and the non-ECC group (n = 19). Model predictions were compared against those of a non-Fontan control group (n = 18) and published literature. We observed strong positive correlations of the mean PA diameter with BSA (r = 0.9, p < 0.05) and age (r = 0.88, p < 0.05) in the ECC group. The absolute percentage differences between our BSA and age model predictions against published literature were less than 16% and 20%, respectively. Predicted PA size for Fontan patients was consistently smaller than the control group. These models may serve as useful references for clinicians and be utilized to construct 3D anatomic models that correspond to patient body size or age.

Investigating hierarchical effects of adaptive signal control system on crash severity using random-parameter ordered regression models incorporating observed heterogeneity.

By handling conflicting traffic movements and establishing dynamic coordination between intersections in real-time, the Adaptive Signal Control System (ASCS) can potentially improve the operation and safety of signalized intersections on a corridor. This study identifies the hierarchical effects of ASCS on the crash severity by exploring the heterogeneous effect of ASCS on the crash severity. Four different random-parameter ordered regression models (two ordered probit models, and two ordered logit models) are developed and compared. The analysis reveals that the random-parameter ordered probit and logit models (ROP and ROL) with observed heterogeneity perform better than the random-parameter ordered probit and logit models (RP and RL) without observed heterogeneity in terms of the Akaike information criteria and the goodness of fit of the model. The ROP model performs better than the ROL model in terms of classification model performance measures. The ROP model enables parameters (i.e., the coefficients of the explanatory variables) to vary as a function of explanatory variables as well as across observations, thus accounting for both observed (captured by available explanatory variables) and unobserved (not captured by available explanatory variables) heterogeneity. The analysis reveals that the presence of ASCS is associated with lower crash severity. In this study, observed heterogeneity of ASCS effects on the crash severity is captured by variables related to the intersection and corridor features. Other contributing factors besides ASCS, such as annual average daily traffic, speed limit, lighting, peak period, crash type (rear-end, angle), and pedestrian involvements, are also associated with the probability of crash severity. Unobserved heterogeneity of the effect of angle crash type on the crash severity is found to exist across the observations. The findings of this research have practical implications for establishing ASCS implementation guidelines in lowering the probability of higher crash severity.

Defects in the Exocyst-Cilia Machinery Cause Bicuspid Aortic Valve Disease and Aortic Stenosis.

BACKGROUND: Bicuspid aortic valve (BAV) disease is a congenital defect that affects 0.5% to 1.2% of the population and is associated with comorbidities including ascending aortic dilation and calcific aortic valve stenosis. To date, although a few causal genes have been identified, the genetic basis for the vast majority of BAV cases remains unknown, likely pointing to complex genetic heterogeneity underlying this phenotype. Identifying genetic pathways versus individual gene variants may provide an avenue for uncovering additional BAV causes and consequent comorbidities. METHODS: We performed genome-wide association Discovery and Replication Studies using cohorts of 2131 patients with BAV and 2728 control patients, respectively, which identified primary cilia genes as associated with the BAV phenotype. Genome-wide association study hits were prioritized based on P value and validated through in vivo loss of function and rescue experiments, 3-dimensional immunohistochemistry, histology, and morphometric analyses during aortic valve morphogenesis and in aged animals in multiple species. Consequences of these genetic perturbations on cilia-dependent pathways were analyzed by Western and immunohistochemistry analyses, and assessment of aortic valve and cardiac function were determined by echocardiography. RESULTS: Genome-wide association study hits revealed an association between BAV and genetic variation in human primary cilia. The most associated single-nucleotide polymorphisms were identified in or near genes that are important in regulating ciliogenesis through the exocyst, a shuttling complex that chaperones cilia cargo to the membrane. Genetic dismantling of the exocyst resulted in impaired ciliogenesis, disrupted ciliogenic signaling and a spectrum of cardiac defects in zebrafish, and aortic valve defects including BAV, valvular stenosis, and valvular calcification in murine models. CONCLUSIONS: These data support the exocyst as required for normal ciliogenesis during aortic valve morphogenesis and implicate disruption of ciliogenesis and its downstream pathways as contributory to BAV and associated comorbidities in humans.

Factors Influencing the Occurrence of Foliar Pathogens in Commercial Watermelon Fields in South Carolina Based on Stratified Cluster Sampling.

The influence of environmental and management factors on the occurrence of foliar pathogens of watermelon was analyzed using survey-sampling data collected from commercial farms in South Carolina in spring 2015 and spring and fall 2016. A stratified two-stage cluster sampling design was used to sample symptomatic watermelon leaves from 56 fields of 27 growers in seven counties representing the main watermelon-producing areas in the state. In the sampling design, counties corresponded to strata, growers to first-stage clusters, and fields to second-stage clusters. Pathogens were identified on 100 leaves collected per field based on reproductive structures that formed on the leaves. Information about previous crops, fruit type, field size, transplanting date, first harvest date, and fungicides applied within 7 days and within 7 to 14 days prior to sampling was obtained from growers. Field alignment was determined with a compass. Survey-specific logistic regression procedures were used to analyze the effect of these factors on the probabilities of pathogen occurrence. Five fungal pathogens, Stagonosporopsis spp., Podosphaera xanthii, Cercospora citrullina, Colletotrichum orbiculare, and Myrothecium sensu lato (s.l.), and the oomycete Pseudoperonospora cubensis were included in the analyses. Among the factors we analyzed, there was a consistent increased probability of occurrence of Stagonosporopsis spp. in fields with a previous cucurbit crop, increasing probabilities of pathogen occurrence with increasing plant age, a lower probability of occurrence of some pathogens on triploid cultivars compared with diploid cultivars, and a decrease in probability of pathogen occurrence in fields aligned toward southwest or west. Application of fungicides significantly reduced the probability of observing C. citrullina, P. cubensis, and Stagonosporopsis spp. in 2015 and P. xanthii in spring 2016. This study emphasizes the importance of crop rotation and fungicide applications to manage foliar diseases of watermelon, particularly gummy stem blight, powdery mildew, and downy mildew. Crop age, cultivar type, and field alignment also were found to significantly influence the probability of pathogen occurrence. To the best of our knowledge, this is the first study examining the influence of various factors on foliar pathogens of watermelon with data collected from commercial fields.

The hepatobiliary complications of malnutrition and nutritional support in adults.

Hepatobiliary complications of hypoalimentation and parenteral nutrition (PN) are widely recognised. Hypoalimentation includes conditions such as anorexia nervosa (AN), obesity malnutrition and liver disease following bariatric surgery. Treatment of the underlying condition causing hypoalimentation can result in an improvement in liver dysfunction. Liver function test abnormalities are also commonly found in patients on PN, with the three main complications being steatosis, cholestasis and biliary system sludge/stones. Patients with intestinal failure receiving PN often have multiple possible aetiologies for liver dysfunction (rather than solely caused by the PN); hence, it is now more commonly referred to as intestinal failure-associated liver disease (IFALD). Liver enzyme abnormalities are very common with long-term PN use and do not always help with monitoring progression of IFALD. A systematic approach is required for investigating liver function abnormalities related to PN. The key management in IFALD is through prevention of sepsis, promoting intestinal health and restoring intestinal continuity where possible. A variety of imaging modalities can be used to investigate, and monitor, the liver disease. Most importantly, patients on PN for more than 28 days should be managed in a large centre with experience in managing intestinal failure to minimise the risk of such complications. Early identification of liver dysfunction is essential and, should it progress despite the above measures, early discussion with an intestinal transplant centre should be encouraged.

Occurrence of Foliar Pathogens of Watermelon on Commercial Farms in South Carolina Estimated with Stratified Cluster Sampling.

A survey of foliar pathogens of watermelon based on two-stage cluster sampling was conducted on commercial farms in South Carolina in spring 2015, spring and fall 2016, and fall 2017. In total, 60 fields from 27 different growers in seven counties representing the main watermelon-producing areas in the state were sampled, using a stratified two-stage cluster sampling approach. In the sampling design, counties corresponded to strata, growers to first-stage clusters, and fields to second-stage clusters. In each field, 100 symptomatic leaves were collected at five equidistant sampling points along four transects encompassing a square shape of 2,500 m2. After collection, pathogens were identified based on reproductive structures formed on leaves during >12 h incubation. Estimates were obtained for the statewide probability of pathogen occurrence and associations between pathogen pairs. Six fungal pathogens, Stagonosporopsis spp., Podosphaera xanthii, Cercospora citrullina, Colletotrichum orbiculare, Myrothecium sensu lato (s.l.), and Corynespora cassiicola; the oomycete Pseudoperonospora cubensis; and three viral pathogens were identified on the examined leaves. With the exception of fall 2017, Stagonosporopsis spp. was the most prevalent pathogen in every season, followed by P. xanthii. The highest occurrence of P. cubensis was in spring 2015; it did not occur in 2016. The highest occurrence of C. orbiculare was in spring 2016; it did not occur in spring 2015. Myrothecium s.l. was the most common pathogen in fall 2017 and the second most common pathogen occurring by itself in fall 2016. The third most common pathogen in fall 2017, Corynespora cassiicola, was not observed in any other season. Eight of the 80 isolates of Stagonosporopsis spp. collected were identified as S. caricae, the rest as S. citrulli. All isolates of S. caricae were found in spring 2015 and originated from two fields in different counties. A total of three positive and five negative associations were found between pathogen pairs co-occurring on the same leaf. A positive association between Stagonosporopsis spp. and C. citrullina was the only significant association between pathogens found in two seasons, spring 2015 and spring 2016. Based on estimates of probability of pathogen occurrence across seasons, Stagonosporopsis spp. and P. xanthii are the most common pathogens on watermelons in South Carolina. This is the first report of C. cassiicola, S. caricae, and Myrothecium s.l. on watermelon in South Carolina.

Monitoring spatial and temporal variation of dissolved oxygen and water temperature in the Savannah River using a sensor network.

Dissolved oxygen is a critical component of river water quality. This study investigated average weekly dissolved oxygen (AWDO) and average weekly water temperature (AWT) in the Savannah River during 2015 and 2016 using data from the Intelligent River® sensor network. Weekly data and seasonal summary statistics revealed distinct seasonal patterns that impact both AWDO and AWT regardless of location along the river. Within seasons, spatial patterns of AWDO and AWT along the river are also evident. Linear mixed effects models indicate that AWT and low and high river flow conditions had a significant impact on AWDO, but added little predictive information to the models. Low and high river flow conditions had a significant impact on AWT, but also added little predictive information to the models. Spatial linear mixed effects models yielded parameter estimates that were effectively the same as non-spatial linear mixed effects models. However, components of variance from spatial linear mixed effects models indicate that 23-32% of the total variance in AWDO and that 12-18% of total variance in AWT can be apportioned to the effect of spatial covariance. These results indicate that location, week, and flow-directional spatial relationships are critically important considerations for investigating relationships between space- and time-varying water quality metrics.

Outcome of elective cholecystectomy for the treatment of gallbladder disease in dogs.

OBJECTIVE To determine mortality rates for dogs undergoing cholecystectomy and variables associated with failure to survive to hospital discharge. DESIGN Retrospective cohort study. ANIMALS 70 dogs that underwent cholecystectomy for biliary tract disease at a companion animal referral hospital from 2009 through 2015. PROCEDURES Medical records of dogs were reviewed and data collected; dogs with biliary diversion surgery were excluded. Included dogs were grouped by whether cholecystectomy had been elective (ie, dogs with no or mild clinical signs, with no indication of biliary obstruction, or that initially underwent surgery for a different procedure) or nonelective (ie, dogs with icterus and questionable patency of the biliary system). Mortality rates (proportions of dogs that failed to survive to hospital discharge) were compared between various groups. RESULTS 45 (64%) dogs were included in the elective group and 25 (36%) in the nonelective group. Group mortality rates were 2% (1/45) and 20% (5/25), respectively, and differed significantly. Overall mortality rate was 9% (6/70). Serum albumin concentration was significantly lower and serum alanine aminotransferase activity and total bilirubin concentration were significantly higher in nonsurviving versus surviving dogs. Dogs with vomiting, signs of lethargy or anorexia, icterus, or azotemia were less likely to survive than dogs without these signs. CONCLUSIONS AND CLINICAL RELEVANCE Dogs that underwent elective cholecystectomy had a considerably lower mortality rate than previously reported. Elective cholecystectomy may be an appropriate recommendation for dogs with early signs of biliary disease to avoid the greater mortality rate associated with more advanced disease and nonelective cholecystectomy.

Comparative Metabolomic Analyses of Ipomoea lacunosa Biotypes with Contrasting Glyphosate Tolerance Captures Herbicide-Induced Differential Perturbations in Cellular Physiology.

Glyphosate-tolerant Ipomoea lacunosa is emerging as a problematic weed in the southeastern United States. Metabolomic profiling was conducted to examine the innate physiology and the glyphosate induced perturbations in two biotypes of I. lacunosa (WAS and QUI) that had contrasting glyphosate tolerance. Compared to the less tolerant QUI-biotype, the innate metabolism of the more tolerant WAS-biotype was characterized by a higher abundance of amino acids, and pyruvate; whereas the sugar profile of the QUI biotype was dominated by the transport sugar sucrose. Glyphosate application (80 g ae/ha) caused similar shikimate accumulation in both biotypes. Compared to QUI, in WAS, the content of aromatic amino acids was less affected by glyphosate treatment, and the content of Ala, Val, Ile, and Pro increased. However, the total sugars decreased by ∼75% in WAS, compared to ∼50% decrease in QUI. The innate, higher proportional abundance, of the transport-sugar sucrose in QUI coud partly explain the higher translocation and greater sensitivity of this biotype to glyphosate. The decrease in sugars, accompanied by an increase in amino acids could delay feedback regulation of upstream enzymes of the shikimate acid pathway in WAS, which could contribute to a greater glyphosate tolerance. Our study, through a metabolomics approach, provides complementary data that elucidates the cellular physiology of herbicide tolerance in Ipomoea lacunosa biotypes.

The Ingestion of Fluorescent, Magnetic Nanoparticles for Determining Fluid-uptake Abilities in Insects.

Fluid-feeding insects ingest a variety of liquids, which are present in the environment as pools, films, or confined to small pores. Studies of liquid acquisition require assessing mouthpart structure and function relationships; however, fluid uptake mechanisms are historically inferred from observations of structural architecture, sometimes unaccompanied with experimental evidence. Here, we report a novel method for assessing fluid-uptake abilities with butterflies (Lepidoptera) and flies (Diptera) using small amounts of liquids. Insects are fed with a 20% sucrose solution mixed with fluorescent, magnetic nanoparticles from filter papers of specific pore sizes. The crop (internal structure used for storing fluids) is removed from the insect and placed on a confocal microscope. A magnet is waved by the crop to determine the presence of nanoparticles, which indicate if the insects are able to ingest fluids. This methodology is used to reveal a widespread feeding mechanism (capillary action and liquid bridge formation) that is potentially shared among Lepidoptera and Diptera when feeding from porous surfaces. In addition, this method can be used for studies of feeding mechanisms among a variety of fluid-feeding insects, including those important in disease transmission and biomimetics, and potentially other studies that involve nano- or micro-sized conduits where liquid transport requires verification.

Pullout strength of 2.0 mm cancellous and cortical screws in synthetic bone.

OBJECTIVE: To determine whether 2.0 mm cancellous screws are superior to 2.0 mm cortical screws when inserted into cancellous and bicortical bone. STUDY DESIGN: Biomechanical study. METHODS: The 2.0 mm cancellous screws and 2.0 mm cortical screws were inserted according to the recommended guidelines in synthetic cancellous and bicortical blocks. Fifteen screw-block constructs per group were tested to failure in axial pullout. Axial pullout strength and yield strength were calculated. Data were analyzed using a one-way ANOVA. RESULTS: The 2.0 mm cortical screws achieved lower axial pullout strength than 2.0 mm cancellous screws in cancellous blocks. The 2.0 mm cortical screws achieved greater pullout strength than 2.0 mm cancellous screws in bicortical blocks. CONCLUSION: The 2.0 mm cancellous screws may offer a biomechanical advantage in bone with thin cortices (<1 mm thick), whereas 2.0 mm cortical screws may be preferred in cortical bone with cortices measuring at least 1 mm in thickness.

Dynamic oceanography determines fine scale foraging behavior of Masked Boobies in the Gulf of Mexico.

During breeding, foraging marine birds are under biological, geographic, and temporal constraints. These contraints require foraging birds to efficiently process environmental cues derived from physical habitat features that occur at nested spatial scales. Mesoscale oceanography in particular may change rapidly within and between breeding seasons, and findings from well-studied systems that relate oceanography to seabird foraging may transfer poorly to regions with substantially different oceanographic conditions. Our objective was to examine foraging behavior of a pan-tropical seabird, the Masked Booby (Sula dactylatra), in the understudied Caribbean province, a moderately productive region driven by highly dynamic currents and fronts. We tracked 135 individuals with GPS units during May 2013, November 2013, and December 2014 at a regionally important breeding colony in the southern Gulf of Mexico. We measured foraging behavior using characteristics of foraging trips and used area restricted search as a proxy for foraging events. Among individual attributes, nest stage contributed to differences in foraging behavior whereas sex did not. Birds searched for prey at nested hierarchical scales ranging from 200 m-35 km. Large-scale coastal and shelf-slope fronts shifted position between sampling periods and overlapped geographically with overall foraging locations. At small scales (at the prey patch level), the specific relationship between environmental variables and foraging behavior was highly variable among individuals but general patterns emerged. Sea surface height anomaly and velocity of water were the strongest predictors of area restricted search behavior in random forest models, a finding that is consistent with the characterization of the Gulf of Mexico as an energetic system strongly influenced by currents and eddies. Our data may be combined with tracking efforts in the Caribbean province and across tropical regions to advance understanding of seabird sensing of the environment and serve as a baseline for anthropogenic based threats such as development, pollution, and commercial fisheries.

Exchange of polar lipids from adults to neonates in Daphnia magna: Perturbations in sphingomyelin allocation by dietary lipids and environmental toxicants.

Because xenosensing nuclear receptors are also lipid sensors that regulate lipid allocation, we hypothesized that toxicant-induced modulation of HR96 activity would alter lipid profiles and the balance between adult survival and neonate production following exposure in Daphnia magna. Adult daphnids were exposed to unsaturated fatty acid- and toxicant- activators or inhibitors of HR96 and later starved to test whether chemical exposure altered allocation toward survival or reproduction. The HR96 activators, linoleic acid and atrazine, decreased reproduction as expected with concomitant changes in the expression of HR96 regulated genes such as magro. The HR96 inhibitors, docosahexaenoic acid (DHA) and triclosan, increased reproduction or neonate starvation survival, respectively. However, pre-exposure to triclosan increased in neonate survival at the expense of reproductive maturation. Lipidomic analysis revealed that sphingomyelins (SM) are predominantly found in neonates and therefore we propose are important in development. DHA and triclosan increased neonatal SM, consistent with HR96's regulation of Niemann-Pick genes. While DHA altered expression of magro, Niemann-Pick 1b, mannosidase, and other HR96-regulated genes as expected, triclosan primarily perturbed sphingomyelinase and mannosidase expression indicating different but potentially overlapping mechanisms for perturbing SM. Overall, SM appears to be a key lipid in Daphnia maturation and further support was provided by carmofur, which inhibits sphingomyelin/ceramide metabolism and in turn severely represses Daphnia maturation and initial brood production. In conclusion, toxicants can perturb lipid allocation and in turn impair development and reproduction.