scholarly journals Environmental impacts on diapause and survival of the alfalfa leafcutting bee, Megachile rotundata

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0254651
Author(s):  
Elisabeth S. Wilson ◽  
Claire E. Murphy ◽  
Covey Wong ◽  
Joseph P. Rinehart ◽  
George D. Yocum ◽  
...  

Megachile rotundata exhibits a facultative prepupal diapause but the cues regulating diapause initiation are not well understood. Possible cues include daylength and temperature. Megachile rotundata females experience changing daylengths over the nesting season that may influence diapause incidence in their offspring through a maternal effect. Juvenile M. rotundata spend their developmental period confined in a nesting cavity, potentially subjected to stressful temperatures that may affect diapause incidence and survival. To estimate the impact of daylength and nest cavity temperature on offspring diapause, we designed a 3D printed box with iButtons that measured nest cavity temperature. We observed nest building throughout the season, monitored nest cavity temperature, and followed offspring through development to measure diapause incidence and mortality. We found that daylength was a cue for diapause, and nest cavity temperature did not influence diapause incidence. Eggs laid during long days had a lower probability of diapause. Siblings tended to have the same diapause status, explaining a lot of the remaining variance in diapause incidence. Some females established nests that contained both diapausing and nondiapausing individuals, which were distributed throughout the nest. Nest cavities reached stressful temperatures, which decreased survival. Mortality was significantly higher in nondiapausing bees and the individuals that were laid first in the nest. In conclusion, we demonstrate a maternal effect for diapause that is mediated by daylength and is independent of nest box temperature.

2020 ◽  
Author(s):  
Hendrik Naujokat ◽  
Klaas Loger ◽  
Juliane Schulz ◽  
Yahya Açil ◽  
Jörg Wiltfang

Aim: This study aimed to evaluate two different vascularized bone flap scaffolds and the impact of two barrier membranes for the reconstruction of critical-size bone defects. Materials & methods: 3D-printed scaffolds of biodegradable calcium phosphate and bioinert titanium were loaded with rhBMP-2 bone marrow aspirate, wrapped by a collagen membrane or a periosteum transplant and implanted into the greater omentum of miniature pigs. Results: Histological evaluation demonstrated significant bone formation within the first 8 weeks in both scaffolds. The periosteum transplant led to enhanced bone formation and a homogenous distribution in the scaffolds. The omentum tissue grew out a robust vascular supply. Conclusion: Endocultivation using 3D-printed scaffolds in the greater omentum is a very promising approach in defect-specific bone tissue regeneration.


2021 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Charlotte K. Marx ◽  
Mareike Reimann ◽  
Martin Diewald

Numerous studies have demonstrated the importance of work–life measures, which are designed to contribute to job quality and help reconcile employees’ work and personal lives. In our study, we asked whether such measures can also work as inducements to prevent employees from voluntarily leaving a firm. We considered flexible working hours and home-based teleworking as flexibility measures that are potentially attractive to all employees. To address the possible bias caused by sketchy implementation and their actual selective use, we chose to examine employees’ perceptions of the offer of these measures. We investigated the moderation of the effect by organizational culture and supervisor and coworker support. We controlled for several indicators of job quality, such as job satisfaction and perceived fairness, to isolate specific ways in which work–life measures contributed to voluntary employee exit, and checked for a selective attractiveness of work–life measures to parents and women as the main caregivers. Using a three-wave panel employer–employee survey, we estimated multilevel mixed-effects logistic regression models for 5452 employees at 127 large German establishments. Our results confirmed that both types of flexibility measures were associated with a lower probability of voluntarily exit. This applied more to men than to women, and the probability was reduced by a demanding organizational culture. Both measures seemed not to be specifically designed to accommodate main caregivers but were attractive to the whole workforce.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David J. Peterman ◽  
Kathleen A. Ritterbush ◽  
Charles N. Ciampaglio ◽  
Erynn H. Johnson ◽  
Shinya Inoue ◽  
...  

AbstractThe internal architecture of chambered ammonoid conchs profoundly increased in complexity through geologic time, but the adaptive value of these structures is disputed. Specifically, these cephalopods developed fractal-like folds along the edges of their internal divider walls (septa). Traditionally, functional explanations for septal complexity have largely focused on biomechanical stress resistance. However, the impact of these structures on buoyancy manipulation deserves fresh scrutiny. We propose increased septal complexity conveyed comparable shifts in fluid retention capacity within each chamber. We test this interpretation by measuring the liquid retained by septa, and within entire chambers, in several 3D-printed cephalopod shell archetypes, treated with (and without) biomimetic hydrophilic coatings. Results show that surface tension regulates water retention capacity in the chambers, which positively scales with septal complexity and membrane capillarity, and negatively scales with size. A greater capacity for liquid retention in ammonoids may have improved buoyancy regulation, or compensated for mass changes during life. Increased liquid retention in our experiments demonstrate an increase in areas of greater surface tension potential, supporting improved chamber refilling. These findings support interpretations that ammonoids with complex sutures may have had more active buoyancy regulation compared to other groups of ectocochleate cephalopods. Overall, the relationship between septal complexity and liquid retention capacity through surface tension presents a robust yet simple functional explanation for the mechanisms driving this global biotic pattern.


RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19788-19796
Author(s):  
Bramha Gupta ◽  
Rushikesh S. Ambekar ◽  
Raphael M. Tromer ◽  
Partha Sarathi Ghosal ◽  
Rupal Sinha ◽  
...  

The impact of micro and nanoplastic debris on our aquatic ecosystem is among the most prominent environmental challenges we face today.


2021 ◽  
Vol 11 (11) ◽  
pp. 4722
Author(s):  
Botan Wang ◽  
Xiaolong Chen ◽  
Yi Wang ◽  
Dong Han ◽  
Baohong Guo ◽  
...  

This work reports the latest observations on the behavior of two Multigap Resistive Plate Chambers (MRPC) under wide high-luminosity exposures, which motivate the development and in-beam test of the sealed MRPC prototype assembled with low-resistive glass. The operation currently being monitored, together with previous simulation results, shows the impact of gas pollution caused by avalanches in gas gaps, and the necessity to shrink the gas-streaming volume. With the lateral edge of the detector sealed by a 3D-printed frame, a reduced gas-streaming volume of ~170 mL has been achieved for a direct gas flow to the active area. A high-rate test of the sealed MRPC prototype shows that, ensuring a 97% efficiency and 70 ps time resolution, the sealed design results in a stable operation current behavior at a counting rate of 3–5 kHz/cm2. The sealed MRPC will become a potential solution for future high luminosity applications.


2021 ◽  
Vol 124 (9) ◽  
pp. 1516-1523
Author(s):  
Lindy M. Kregting ◽  
Sylvia Kaljouw ◽  
Lucie de Jonge ◽  
Erik E. L. Jansen ◽  
Elleke F. P. Peterse ◽  
...  

Abstract Background Many breast, cervical, and colorectal cancer screening programmes were disrupted due to the COVID-19 pandemic. This study aimed to estimate the effects of five restart strategies after the disruption on required screening capacity and cancer burden. Methods Microsimulation models simulated five restart strategies for breast, cervical, and colorectal cancer screening. The models estimated required screening capacity, cancer incidence, and cancer-specific mortality after a disruption of 6 months. The restart strategies varied in whether screens were caught up or not and, if so, immediately or delayed, and whether the upper age limit was increased. Results The disruption in screening programmes without catch-up of missed screens led to an increase of 2.0, 0.3, and 2.5 cancer deaths per 100 000 individuals in 10 years in breast, cervical, and colorectal cancer, respectively. Immediately catching-up missed screens minimised the impact of the disruption but required a surge in screening capacity. Delaying screening, but still offering all screening rounds gave the best balance between required capacity, incidence, and mortality. Conclusions Strategies with the smallest loss in health effects were also the most burdensome for the screening organisations. Which strategy is preferred depends on the organisation and available capacity in a country.


2006 ◽  
Vol 120 (3) ◽  
pp. 342
Author(s):  
Serge Larivière ◽  
Lyle R. Walton ◽  
François Messier

Striped Skunks (Mephitis mephitis) are important predators of duck eggs in the Canadian prairies. We estimated the impact of individual Striped Skunks on duck nests by intensive observations of foraging movements and depredation of duck nests in southern Saskatchewan, 1993-1994. Nightly, skunk movements were variable (range 0-20 km per night), and did not differ among seasons for females, or between males and females during the parturition/rearing season. Overall, nightly movement of Striped Skunks averaged 7.4 km for females (SD = 5.9 km, n = 20 females) and 6.7 km for males (SD = 3.2 km, n = 5 males). During 1,873 h of radio-tracking, we observed depredation of 10 duck nests by 8 skunks (7 F, 1 M). Using our observed estimate of one depredation for every 187 h, and averaged nightly activity of 8-10 h per night, we estimated that individual skunks find one duck nest every 19-23 nights. Thus, during the 60-day nesting season for ducks (mid-May to mid-July), individual skunks probably find 2-3 duck nests. These observations reinforce the growing evidence that, at normal duck nest densities (<2.5 nests/ha), depredation of eggs by Striped Skunks is opportunistic, and the impact of Striped Skunks on duck nests is a direct function of Striped Skunk abundance.


2021 ◽  
pp. 003464462110552
Author(s):  
Patrick L. Mason

The current wave of technological change is driven by automation, the process of using computers to improve the labor process, viz., increasing the quantity and quality of work “by means of computer-controlled equipment.” Automation has had and will continue to have heterogeneous economic effects across alternative social groups—altering racial and gender inequality. This study empirically examines the relationship between the racial and gender density of occupations and the probability of automation of both minor and broad occupations. Regression analysis is used to uncover correlations between future employment change and the current racial and ethnic composition of occupations, alerting us to whether future employment growth will have a negative or positive association with occupations where each racial group of workers is currently concentrated. Increases in automation are correlated with increases in labor income inequality and increases in racial and gender employment differences. Male jobs may suffer more technological unemployment than female jobs. Specifically, within each racial group high density male jobs have a greater probability of automation (and lower probability of future demand) than high density female jobs. High density White female jobs appear to be most complementary to automation, while the high density occupations of racial minority men appear to be least complementary to automation.


2017 ◽  
Vol 34 (5) ◽  
pp. 385-399 ◽  
Author(s):  
Vendula Belackova ◽  
Barbara Janikova ◽  
Jaroslav Vacek ◽  
Hana Fidesova ◽  
Michal Miovsky

Background: In September 2012, a series of methanol poisonings occurred in the Czech Republic as a result of an influx of illicit alcohol into (predominantly) cheap alcoholic beverages on the retail market. The public authorities decided to prevent public health risks by prohibiting sales of liquors that contained more than 20% alcohol (> 20% liquor). The “partial” prohibition lasted for almost two weeks, but the poisonings still continued. This article assesses the impact of the methanol poisoning risks and the (partial) prohibition on alcohol drinking patterns, and describes the understanding of risks and their mitigation in vulnerable groups. Methods: The rapid assessment and response method (RAR) was used during the (partial) alcohol prohibition. Semi-structured interviews were conducted with respondents recruited for the study in alcohol-intake settings (e.g., bars and restaurants, street alcohol outlets) in six regions. In total, 107 alcohol users were interviewed, mostly with risky drinking patterns (69% scored ≥ 1 on the CAGE scale), and 53 alcohol retailers/staff members serving alcohol. Results: About one third of the alcohol users in the study (35%) drank > 20% liquors during the prohibition; a higher score on the CAGE scale was associated with a lower probability of drinking > 20% liquors during the period of the prohibition, probably because of the perception of being at high risk of poisoning. There was some increase in drinking liquors with an alcohol content less than 20%. Those who continued drinking > 20% liquors typically did so in the belief that some sources of these were safe. Conclusions: Public policies aimed at reducing the risk of methanol poisonings in emergency situations should adopt broader measures than those focusing on market control. These measures include increased access to brief interventions, addressing the strategies that alcohol consumers adopt to prevent risk, and, in general, helping consumers make informed choices to prevent further fatalities.


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