scholarly journals Active behaviour of terrestrial caterpillars on the water surface

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11971
Author(s):  
Masakazu Hayashi ◽  
Shinji Sugiura
Keyword(s):  
Water Surface ◽  
Field Conditions ◽  
Aquatic Environments ◽  
Defensive Behaviour ◽  
Forward Movement ◽  
Aquatic Predators ◽  
Potential Factors ◽  
Thoracic Legs ◽  
Plant Habitat ◽  
The Relationship

Most butterfly and moth larvae (Lepidoptera) are terrestrial. When terrestrial caterpillars accidentally fall into water, they may drown or be preyed upon by aquatic predators before they can safely reach land. However, how terrestrial caterpillars escape aquatic environments and predators remains unclear. In July 2018, we observed a terrestrial caterpillar actively moving forward on the surface of a pond in Japan until it successfully reached the shore. To further investigate this behaviour in terrestrial caterpillars, we experimentally placed larvae of 13 moth species (four families) on a water surface under laboratory and field conditions. All caterpillars floated. Larvae of seven species moved forward on the water surface, whereas those of six species did not. A total of two types of behaviour were observed; in Dinumma deponens, Hypopyra vespertilio, Spirama retorta, Laelia coenosa, Lymantria dispar (all Erebidae), and Naranga aenescens (Noctuidae), larvae swung their bodies rapidly from side to side to propel themselves along the water surface (i.e., undulatory behaviour); in contrast, larvae of Acosmetia biguttula (Noctuidae) rapidly moved the abdomen (posterior segments) up and down for propulsion along the water surface (i.e., flick behaviour). Although thoracic legs were not used for undulatory and flick behaviour, rapid movements of the abdomen were used to propel caterpillars on the water surface. We also observed that undulatory and flick behaviour on the water surface aided caterpillars in escaping aquatic predators under field conditions. In addition, we investigated the relationship between body size and undulatory behaviour on the water surface in the erebid S. retorta under laboratory conditions. The frequency and speed of forward movement on the water surface increased with body length. Together, these results show that the rapid movement of elongated bodies results in forward propulsion on the water surface, allowing some terrestrial caterpillars to avoid drowning or aquatic predators. We further suggested potential factors related to morphology, host plant habitat, and defensive behaviour that may have led to the acquisition of aquatic behaviour in terrestrial caterpillars.

scholarly journals Quinoa for the Brazilian Cerrado: Agronomic Characteristics of Elite Genotypes under Different Water Regimes

Plants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1591
Author(s):  
Patrícia Carvalho da Silva ◽  
Walter Quadros Ribeiro Junior ◽  
Maria Lucrecia Gerosa Ramos ◽  
Sonia Maria Costa Celestino ◽  
Alberto do Nascimento Silva ◽  
...  
Keyword(s):  
Grain Quality ◽  
Winter Season ◽  
Field Conditions ◽  
Water Restriction ◽  
Water Regimes ◽  
Agronomic Characteristics ◽  
Relative Water ◽  
Different Seasons ◽  
The Relationship

Quinoa stands out as an excellent crop in the Cerrado region for cultivation in the off-season or irrigated winter season. Here, we tested the effects of different water regimes on the agronomic characteristics, physiology, and grain quality of different elite quinoa genotypes under field conditions. The experiment was conducted under field conditions at Embrapa Cerrados (Planaltina, DF, Brazil). The experimental design was in randomized blocks, in a split-plot scheme, with four replications. The plots were composed of 18 quinoa genotypes and modified BRS Piabiru (the currently used genotype), and the split-plots were divided into 4 different water regimes. The following variables were evaluated: productivity and productivity per unit of applied water (PUAA), plant height, flavonoids, anthocyanins, gas exchange, chlorophyll, leaf proline, and relative water content. Our results showed that water regimes between 309 and 389 mm can be recommended for quinoa in the Cerrado region. CPAC6 and CPAC13 presented the highest yield and PUAA under high and intermediate WRs, and hence were the most suitable for winter growth under irrigation. CPAC17 is most suitable for off-season growth under rainfed conditions, as it presented the highest PUAA under the low WRs (247 and 150). CPAC9 stood out in terms of accumulation of flavonoids and anthocyanins in all WRs. Physiological analyses revealed different responses of the genotypes to water restriction, together with symptoms of stress under lower water regimes. Our study reinforces the importance of detailed analyses of the relationship between productivity, physiology, and water use when choosing genotypes for planting and harvest in different seasons.

Objective and Subjective Outcomes in Patients with Hearing Aids: A Cross-Sectional, Comparative, Associational Study

2021 ◽  
pp. 1-9
Author(s):  
Xunyi Wang ◽  
Yun Zheng ◽  
Gang Li ◽  
Jingzhe Lu ◽  
Yan Yin
Keyword(s):  
Hearing Aids ◽  
Patient Reported Outcomes ◽  
Cross Sectional ◽  
Patient Reported ◽  
Objective Tests ◽  
The Difference ◽  
Potential Factors ◽  
Positive Correlations ◽  
The Relationship ◽  
Subjective Outcomes

<b><i>Introduction:</i></b> Outcome assessment for hearing aids (HAs) is an essential part of HA fitting and validation. There is no consensus about the best or standard approach for evaluating HA outcomes. And, the relationship between objective and subjective measures is ambiguous. This study aimed to determine the outcomes after HA fitting, explore correlations between subjective benefit and acoustic gain improvement as well as objective audiologic tests, and investigate several variables that may improve patients’ perceived benefits. <b><i>Methods:</i></b> Eighty adults with bilateral symmetrical hearing loss using HAs for at least 1 month were included in this study. All subjects completed the pure tone average (PTA) threshold and word recognition score (WRS) tests in unaided and aided conditions. We also administered the Chinese version of International Outcome Inventory for Hearing Aids (IOI-HA), to measure participants’ subjective benefits. Objective HA benefit (acoustic gain improvement) was defined as the difference in thresholds or scores between aided and unaided conditions indicated with ΔPTA and ΔWRS. Thus, patients’ baseline hearing levels were taken into account. Correlations were assessed among objective audiologic tests (PTA and WRS), acoustic gain improvement (ΔPTA and ΔWRS), multiple potential factors, and IOI-HA overall scores. <b><i>Results:</i></b> PTA decreased significantly, but WRS did not increase when aided listening was compared to unaided listening. Negative correlations between PTAs and IOI-HA scores were significant but weak (<i>r</i> = −0.370 and <i>r</i> = −0.393, all <i>p</i> &#x3c; 0.05). Significant weak positive correlations were found between WRSs and IOI-HA (<i>r</i> = 0.386 and <i>r</i> = 0.309, all <i>p</i> &#x3c; 0.05). However, there was no correlation among ΔPTA, ΔWRS, and IOI-HA (<i>r</i> = 0.056 and <i>r</i> = −0.086, all <i>p</i> &#x3e; 0.05). Moreover, 2 nonaudiological factors (age and daily use time) were significantly correlated with IOI-HA (<i>r</i> = −0.269 and <i>r</i> = 0.242, all <i>p</i> &#x3c; 0.05). <b><i>Conclusions:</i></b> Correlations among objective audiologic tests, acoustic gain, and subjective patient-reported outcomes were weak or absent. Subjective questionnaires and objective tests do not reflect the same hearing capability. Therefore, it is advisable to evaluate both objective and subjective outcomes when analyzing HA benefits on a regular basis and pay equal attention to nonaudiological and audiological factors.

scholarly journals The Relationship between Dissolution Behavior and the Toxicity of Silver Nanoparticles on Zebrafish Embryos in Different Ionic Environments

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 652 ◽  
Author(s):  
Wang Lee ◽  
Eungwang Kim ◽  
Hyun-Ju Cho ◽  
Taejoon Kang ◽  
Bongsoo Kim ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Polyethylene Glycol ◽  
Zebrafish Embryo ◽  
Antibacterial Properties ◽  
Dissolution Behavior ◽  
Aquatic Environments ◽  
Zebrafish Embryos ◽  
Negative Effects ◽  
The Relationship ◽  
Water Filters

A silver nanoparticle is one of the representative engineered nanomaterials with excellent optical, electrical, antibacterial properties. Silver nanoparticles are being increasingly used for medical products, water filters, and cosmetics, etc. However, silver nanoparticles are known to cause adverse effects on the ecosystem and human health. To utilize silver nanoparticles with minimized negative effects, it is important to understand the behavior of silver nanoparticles released to the environment. In this study, we compared toxicity behaviors of citrate-stabilized silver nanoparticles with polyethylene glycol coated silver nanoparticles in two different ionic environments, which are aquatic environments for developing zebrafish embryo. Depending on the composition of the ionic environment, citrate-stabilized silver nanoparticles and polyethylene glycol coated silver nanoparticles exhibited different behaviors in dissolution, aggregation, or precipitation, which governed the toxicity of silver nanoparticles on zebrafish embryos.

Relationship between Pseudomonas aeruginosa and Bacterial Indicators in Polluted Natural Waters

1991 ◽  
Vol 24 (2) ◽  
pp. 121-124 ◽  
Author(s):  
A. de Vicente ◽  
J. C. Codina ◽  
P. Romero
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Natural Waters ◽  
Pollution Index ◽  
Close Correlation ◽  
Aquatic Environments ◽  
Faecal Coliforms ◽  
Faecal Pollution ◽  
The Relationship ◽  
Faecal Indicators ◽  
Faecal Streptococci

The relationship between Pseudomonas aeruginosa and the faecal pollution index (total coliforms, faecal coliforms and faecal streptococci) in natural waters was established. Water samples were collected from several aquatic environments in Málaga (Spain). P. aeruginosa counts and isolation frequencies were clearly associated with the degree of faecal pollution of the studied water. The results confirmed that domestic sewage was the major source of P. aeruginosa in river and seawater, being isolated from sewage at concentrations about 105 cfu/100 ml. There was a close correlation between the P. aeruginosa concentration and the densities of the three faecal indicators in both river and marine waters. A significant correlation was not observed in waters with little faecal pollution because P. aeruginosa was only occasionally isolated from these waters and at very low densities. P. aeruginosa concentrations in sewage and polluted natural waters were generally 3-4 log lower than the TC densities and 2 log lower than FC and FS concentrations. TC, FC and FS could be considered adequate indicators of the presence and densities of P. aeruginosa in natural waters, especially TC in freshwaters and FS in seawater respectively, as these parameters showed the best correlations and the most parallel inactivation processes with P. aeruginosa in each environment.

Survival of Escherichia coli on Lettuce under Field Conditions Encountered in the Northeastern United States

2017 ◽  
Vol 80 (7) ◽  
pp. 1214-1221 ◽  
Author(s):  
Daniel L. Weller ◽  
Jasna Kovac ◽  
Sherry Roof ◽  
David J. Kent ◽  
Jeffrey I. Tokman ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Microbial Contamination ◽  
Field Conditions ◽  
Risk Assessments ◽  
Most Probable Number ◽  
Northeastern United States ◽  
Probable Number ◽  
E Coli ◽  
The Relationship ◽  
Sample Time

ABSTRACT Although wildlife intrusion and untreated manure have been associated with microbial contamination of produce, relatively few studies have examined the survival of Escherichia coli on produce under field conditions following contamination (e.g., via splash from wildlife feces). This experimental study was performed to estimate the die-off rate of E. coli on preharvest lettuce following contamination with a fecal slurry. During August 2015, field-grown lettuce was inoculated via pipette with a fecal slurry that was spiked with a three-strain cocktail of rifampin-resistant nonpathogenic E. coli. Ten lettuce heads were harvested at each of 13 time points following inoculation (0, 2.5, 5, and 24 h after inoculation and every 24 h thereafter until day 10). The most probable number (MPN) of E. coli on each lettuce head was determined, and die-off rates were estimated. The relationship between sample time and the log MPN of E. coli per head was modeled using a segmented linear model. This model had a breakpoint at 106 h (95% confidence interval = 69, 142 h) after inoculation, with a daily decrease of 0.70 and 0.19 log MPN for 0 to 106 h and 106 to 240 h following inoculation, respectively. These findings are consistent with die-off rates obtained in similar studies that assessed E. coli survival on produce following irrigation. Overall, these findings provide die-off rates for E. coli on lettuce that can be used in future quantitative risk assessments.

scholarly journals Honeybees use their wings for water surface locomotion

2019 ◽  
Vol 116 (49) ◽  
pp. 24446-24451 ◽  
Author(s):  
Chris Roh ◽  
Morteza Gharib
Keyword(s):  
Water Surface ◽  
Adhesive Force ◽  
Jet Stream ◽  
Forward Movement ◽  
Surrounding Water ◽  
Air Water Interface ◽  
Acceleration And Deceleration ◽  
Periodic Acceleration ◽  
Speed Up ◽  
Horizontal Momentum

Honeybees display a unique biolocomotion strategy at the air–water interface. When water’s adhesive force traps them on the surface, their wetted wings lose ability to generate aerodynamic thrust. However, they adequately locomote, reaching a speed up to 3 body lengths·s−1. Honeybees use their wetted wings as hydrofoils for their water surface propulsion. Their locomotion imparts hydrodynamic momentum to the surrounding water in the form of asymmetric waves and a deeper water jet stream, generating ∼20-μN average thrust. The wing kinematics show that the wing’s stroke plane is skewed, and the wing supinates and pronates during its power and recovery strokes, respectively. The flow under a mechanical model wing mimicking the motion of a bee’s wing further shows that nonzero net horizontal momentum is imparted to the water, demonstrating net thrust. Moreover, a periodic acceleration and deceleration of water are observed, which provides additional forward movement by “recoil locomotion.” Their water surface locomotion by hydrofoiling is kinematically and dynamically distinct from surface skimming [J. H. Marden, M. G. Kramer, Science 266, 427–430 (1994)], water walking [J. W. M. Bush, D. L. Hu, Annu. Rev. Fluid Mech. 38, 339–369 (2006)], and drag-based propulsion [J. Voise, J. Casas, J. R. Soc. Interface 7, 343–352 (2010)]. It is postulated that the ability to self-propel on a water surface may increase the water-foraging honeybee’s survival chances when they fall on the water.

scholarly journals Buried Depth of a Submarine Pipeline Based on Anchor Penetration

2019 ◽  
Vol 7 (8) ◽  
pp. 257
Author(s):  
Xueyuan Zhu ◽  
Qinglong Hao ◽  
Jie Zhang
Keyword(s):  
Numerical Simulation ◽  
Penetration Depth ◽  
Water Depth ◽  
Calculation Method ◽  
Water Surface ◽  
Submarine Pipeline ◽  
Projected Area ◽  
Actual Measurement ◽  
Calculation Results ◽  
The Relationship

Anchor penetration is an important issue involved in the study of submarine pipeline damage accidents. To explore the penetration of a ship’s anchor under certain conditions, this study investigated the motion and force of an anchor and formulated a calculation method for the bottoming speed of an anchor. Meanwhile, the depth of anchor penetration was calculated under different conditions according to bottoming speed through programming. Finally, the reliability of the calculation method for the penetration depth was verified by comparing the actual measurement and the numerical simulation. On the basis of the findings, the calculation results were further analyzed, and conclusions were derived regarding the relationship between anchor mass, the horizontal projected area of the anchor, the anchor height on the water surface, and water depth. The conclusions provide suggestions for the application of anchor penetration in terms of seabed depth with certain reference values.

Actinomycetes in the Elbow River Basin, Alberta, Canada

2003 ◽  
Vol 38 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Beryl Zaitlin ◽  
Susan B. Watson ◽  
Jamieson Dixon ◽  
Deborah Steel
Keyword(s):  
Drinking Water ◽  
Agricultural Land ◽  
Water Source ◽  
Aquatic Environments ◽  
Drinking Water Source ◽  
E Coli ◽  
Stream Discharge ◽  
Stream Characteristics ◽  
The Relationship ◽  
The City

Abstract Actinomycetes can produce significant amounts of the earthy-muddy odour compounds geosmin and 2-methylisoborneol (MIB). These filamentous bacteria are found in both terrestrial and aquatic environments, and are particularly abundant in soil. They can enter freshwater systems via terrestrial runoff and subsequently cause taste and odour outbreaks in drinking water. Since it is well known that actinomycete growth and odour production is modified strongly by environmental factors such as moisture and nutrient levels, we hypothesized that watershed and stream characteristics should influence the potential odour impact of soil runoff on surface water. In this study, 1) the relationship between actinomycete abundance and characteristics such as stream discharge, turbidity and Escherichia coli levels was investigated, and 2) actinomycetes from contrasting terrestrial sources were examined for differences in their geosmin and MIB production. Actinomycetes and stream characteristics were sampled from the Elbow River, an important drinking water source for the City of Calgary (Alberta, Canada), and three tributary streams. Actinomycetes from forested regions and agricultural land were tested for taste and odour compound production. Actinomycete levels in streams were found to correlate closely with E. coli levels and to a lesser extent with turbidity, suggesting that actinomycetes are particularly abundant in runoff from terrestrial sources with fecal contamination. Most of the 18 actinomycete isolates tested were able to produce geosmin and/or MIB regardless of their terrestrial sources, suggesting that taste and odour outbreaks due to actinomycetes may be more influenced by differences in abundance than differences in source.

Neuropathic Pain, Depression, and Cardiovascular Disease: A National Multicenter Study

2015 ◽  
Vol 44 (3) ◽  
pp. 130-137 ◽  
Author(s):  
Jacquelyn J. Cragg ◽  
Vanessa K. Noonan ◽  
Luc Noreau ◽  
Jaimie F. Borisoff ◽  
John K. Kramer
Keyword(s):  
Cardiovascular Disease ◽  
Neuropathic Pain ◽  
Self Report ◽  
Secondary Complications ◽  
Cross Sectional ◽  
Increased Risk ◽  
Cord Injury ◽  
Emerging Risk ◽  
Potential Factors ◽  
The Relationship

Background: Individuals with spinal cord injury (SCI) have a more than twofold increased risk of heart disease and stroke compared with able-bodied individuals. The increased risk appears to be in excess of the risk conferred by several well-established risk factors, including diabetes, hypertension, and sex. This raises the question whether other factors, secondary to SCI, are also contributing to the development of cardiovascular disease (CVD). Two potential factors associated with SCI and CVD are pain and depression. Both are frequently reported among individuals with SCI, develop in the acute stages of injury, and are commonly described as severe. Therefore, the primary aim of this study was to examine the relationship between pain (and types of pain) and depression with CVD among individuals with SCI. Methods: A total of 1,493 individuals (referred sample) with chronic SCI participated in a self-report cross-sectional multicenter Canada-wide survey from 2011-2012 (mean age ± standard deviation: 49.6 ± 13.9 years). Results: After adjustment for age, sex, and injury characteristics, neuropathic pain and depression were significantly and independently associated with CVD (adjusted odds ratio and 95% confidence interval: 2.27 (1.21, 4.60) for neuropathic pain; 4.07 (2.10, 7.87) for depression). In contrast to neuropathic pain, non-neuropathic pain was not significantly associated with CVD (p = 0.13). Conclusion: In conclusion, these data illustrate important interrelationships between secondary complications following SCI, as well as raise the possibility of neuropathic pain (versus nociceptive pain) as a novel and emerging risk factor for CVD.

scholarly journals Job Hopping Behavior among Coffee Shops Employees in Malaysia

2021 ◽  
Vol 11 (3) ◽  
pp. 118
Author(s):  
Hazrina Ghazali ◽  
Zulaikha Hizreen Hashim ◽  
Maisarah Ishak
Keyword(s):  
Job Satisfaction ◽  
Organizational Support ◽  
Coffee Shop ◽  
Klang Valley ◽  
Potential Factors ◽  
Relationship Of ◽  
The Relationship ◽  
Coffee Shops ◽  
Valley Area ◽  
Organization Support

Job hopping behavior may have an adverse effect on both employers and employees. For the perspective of employee, there are many factors might influence an employee's decision to job hop including salary dissatisfaction or a better offer elsewhere. The issue of job hopping has been a serious concern for many organizations, and the coffee shops industry is no exception. Therefore, the goal of this research is to discover potential factors influencing to job hopping behavior among coffee shops employees, as well as the relationship of identified factors with job hopping. Job satisfaction, financial and perceived organizational support were the three factors investigated in this research. A total of 231 questionnaires were distributed to employees who are currently working in the coffee shops in Klang Valley area and 215 usable responses returned for a response rate of 93.1 percent. The collected data was analyzed by using Statistical Package for Social Sciences (SPSS) latest version. Results of the job satisfaction (mean= 3.5636), financial (m=3.5622) and perceived organization support (mean=3.5601) shows score lean towards agreement level. Additionally, findings showed that the correlation of all the variables were weak correlated. A multiple regression also was run to predict job hopping behaviour with the three independent variables. Results found that only 6.9% of variance in coffee shops’ employees was explained by job satisfaction, financial and perceived organization support (R² = .069). Even though the findings of this research found that these three variables did not have a direct impact on coffee shop employees' decision to job hop, the findings may provide some guidance and alert coffee shop owners or managers to the importance of these three variables in the coffee shops industry in order to minimize job hopping and will be discussed further in this paper.

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