Unprotected Conditions Research Articles

Impact of Protective Measures on Mealybug and Red Cotton Bug Incidence in Bt Cotton Hybrids

The study investigated the influence of mealybug and red cotton bug populations on different cotton hybrids under protected and unprotected conditions. The results revealed that under protected conditions, the mealybug, Phenacoccus solenopsis population was significantly lower (0.23/plant) compared to unprotected conditions (1.14/plant). Among the hybrids, G. Cot. Hy. 10 BG II (0.35/plant) and Ajeet 155 BG II (0.40/plant) showed the lowest mealybug populations, while RCH 2 BG II recorded the highest (1.19/plant). Significant differences were observed in the interaction between protection levels and hybrids with lower pest populations recorded under protected conditions. Similarly, for the red cotton bug, the population was significantly lower under protected conditions (0.23/plant) compared to unprotected (0.87/plant). G.Cot.Hy.10 BG II showed the lowest red cotton bug, Dysdercus cingulatus population (0.24/plant), while RCH 2 BG II had the highest population under unprotected conditions (1.24/plant). Significant differences were found in the interaction of protection levels, hybrids, and periods with protected conditions consistently showing lower pest incidences.

Natural Enemies in Different Bt Cotton Hybrids under Protected and Unprotected Conditions

A field experiment was conducted to analyse the population dynamics of natural enemies including Chrysoperla, coccinellids, and spiders, in Bt cotton under both protected and unprotected conditions. The results indicated that the population of natural enemies was significantly higher under unprotected conditions compared to protected fields, where insecticides were applied. Among the tested hybrids, G. Cot. Hy.10 BG Ⅱ recorded the highest predator activity, showing a greater population of Chrysoperla, coccinellids, and spiders in unprotected conditions. In contrast, the lowest predator activity was observed in RCH 2 BG Ⅱ, while Ajeet 155 BG Ⅱ and ATM BG Ⅱ had minimal natural enemy presence. These findings highlight the importance of unprotected conditions in preserving natural enemies and suggest that certain Bt hybrids, such as G. Cot. Hy.10 BG Ⅱ, may better support predator populations. This research is crucial for understanding how insecticide use affects natural enemy populations and identifying hybrids that promote predator activity. Incorporating natural enemies into pest management strategies can enhance the sustainability of cotton production. Predators of pests, coccinellids and Chrysoperla, were observed from the 33rd to 52nd, whereas spider populations were observed from the 31st to 52nd SW under unprotected conditions.

Assessment of Yield Losses due to Major Insect Pests in Sesame

Yield losses due to major insect pests viz., leaf webber and capsule borer Antigastra catalaunalis (Duponchel) and gall fly Asphondylia sesami (Felt) in promising sesame varieties was carried out at the Regional Agricultural Research Station, Jagtial, during summer, 2019 and 2020 under protected and unprotected conditions. The highest % avoidable yield losses was recorded in Hima variety (35.45) followed by Swetha, Sharada, GT 10, Madhavi, Gouri, VRI 1 and Rajeswari with 34.27, 33.17, 32.48, 31.05, 30.53, 30.01 and 29.75, respectively. Regarding cost benefit ratio, highest was recorded in Hima variety (1:2.23) followed by Swetha (1:2.05) and Sharada (1:1.75).

Sulfated Laminarin Polysaccharides Reduce the Adhesion of Nano-COM Crystals to Renal Epithelial Cells by Inhibiting Oxidative and Endoplasmic Reticulum Stress.

Purpose: Adhesion between calcium oxalate crystals and renal tubular epithelial cells is a vital cause of renal stone formation; however, the drugs that inhibit crystal adhesion and the mechanism of inhibition have yet to be explored. Methods: The cell injury model was constructed using nano-COM crystals, and changes in oxidative stress levels, endoplasmic reticulum (ER) stress levels, downstream p38 MAPK protein expression, apoptosis, adhesion protein osteopontin expression, and cell-crystal adhesion were examined in the presence of Laminarin polysaccharide (DLP) and sulfated DLP (SDLP) under protected and unprotected conditions. Results: Both DLP and SDLP inhibited nano-COM damage to human kidney proximal tubular epithelial cell (HK-2), increased cell viability, decreased ROS levels, reduced the opening of mitochondrial membrane permeability transition pore, markedly reduced ER Ca2+ ion concentration and adhesion molecule OPN expression, down-regulated the expression of ER stress signature proteins including CHOP, Caspase 12, and p38 MAPK, and decreased the apoptosis rate of cells. SDLP has a better protective effect on cells than DLP. Conclusions: SDLP protects HK-2 cells from nano-COM crystal-induced apoptosis by reducing oxidative and ER stress levels and their downstream factors, thereby reducing crystal-cell adhesion interactions and the risks of kidney stone formation.

Study on the impact of debris flow from tailings dam failure on shale gas well station

The shale gas well station plays a critical role in the extraction of shale gas, and its safety status exerts significant influence not only on shale gas production but also on the ecological balance of the surrounding environment. To investigate the response characteristics of the shale gas well station under the impact of tailings dam failure debris flow, a comprehensive analysis was conducted using a combination of physical modeling and numerical simulation. The analysis focused on the dynamic inundation process and the impact siltation law caused by the downstream flow of tailings dam failure debris at the shale gas well station. The depth of inundation and the extent of siltation damage were employed as key parameters for characterization. Experimental findings revealed that the downstream mudflow inundation process could be divided into three distinct stages: rapid increase (0–60 s), steady increase (60–106 s), and slow advance (106–250 s). The pattern of mudflow siltation height variation at the well station exhibited an initial rise, followed by a subsequent decline and eventual stabilization. The highest siltation volumes recorded at measurement points A to D were 4.4, 4, 5.2, and 6 m, respectively. Additionally, by employing computational fluid dynamics, numerical calculations were performed under unprotected conditions, with the error between the calculated conclusions and the test results not exceeding 15%. Furthermore, the blocking effect of 8 and 16 m debris flow blocking dam on the debris flow was thoroughly investigated. The study demonstrated that the check dam with a height of 16 m yielded the most effective blockage, resulting in the highest sediment siltation height of 0.4 m. The research results provide some reference for the prevention and control of debris flow disasters.

Studies on Performance of Bt Cotton Hybrids against Jassids (Amrasca bigutulla bigutulla Ishida) During Summer Season

Cotton (Gossypium hirsutum. L) is indeed a significant cash crop grown in three agro-climatic zones of India. The Indian subcontinent is considered the birthplace of cotton, and it has been a crucial part of human civilization for centuries. It is renowned as the most important natural fibre or vegetable wool and has been cultivated for both domestic consumption and export purpose for proximately 111 countries worldwide. Cotton is a vital crop that plays a significant role in the global economy. It provides livelihoods for over 250 million people worldwide and accounts for nearly 7% of the labour force in developing countries. The field experiment was carried out at Agricultural Research Station (ARS), Adilabad, Telangana during summer 2022-23. A Total of 8 Bt cotton hybrids were evaluated against jassids of cotton under unprotected conditions. Lowest population of jassids were recorded in hybrid NCS-2778 (3.76 jassids per 3 leaves), followed by RCH-659 (5.41 jassids), PRADEEP (6.27 jassids), MOKSHA (6.45jassids per 3 leaves). The highest population of jassids were recorded in JADHU (9.91 jassids) and MONEY MAKER (7.70 jassids).

Corrosion Studies of Temperature-Resistant Zinc Alloy Sacrificial Anodes and Casing Pipe at Different Temperatures.

In order to solve the problem of external corrosion of deep well casing in oil and gas fields, a new type of high-temperature-resistant zinc alloy sacrificial anode material was used. The temperature and corrosion resistance of the new anode material and TP140 casing were investigated by simulating the high-temperature working conditions of a deep well in an oil field using high-temperature and high-pressure corrosion tests and electrochemical tests. The results showed that at 100-120 °C, the corrosion rate of TP140 protected by a sacrificial anode was only one-tenth of that under unprotected conditions, and the minimum corrosion rate of TP140 protected by a sacrificial anode at 100 °C was 0.0089 mm/a. The results of the dynamic potential polarization curve showed that the corresponding corrosion current density of TP140 first increased and then decreased with the increase in temperature. The self-corrosion potential in sacrificial anode materials first increased and then decreased with the increase in temperature, and the potential difference with TP140 gradually decreased.

Seasonal abundance of major insect pests of potato (Solanum tuberosum) and their natural enemies in Karnataka, India

It is essential to know the seasonal occurrences of various pests of potato along with their natural enemies so that timely management practices could be advised to farmers to avoid losses. Therefore, field studies on seasonal incidence of major insect pests of potato and their natural enemies were carried out at the All India Co-ordinated Research Project on Potato, Main Agricultural Research Station, University of Agricultural Sciences, Dharwad, India during Kharif 2016 and 2017; and at Hangaraki, a village near Dharwad during Rabi 2016-17 and 2017-18. The observations on the seasonal abundance of potato insects, mites, and their natural enemies were recorded at weekly intervals starting from 20 days after the emergence of the plant till harvest. These observations were made under unprotected conditions. During Kharif season, the sucking pests were active from July second week and continued up to harvesting of the crop and the maximum pest population was observed during August second week to September first week. The peak activity of the shoot borer, Leucinodes orbonalis Guenee was noticed during the 35th Meteorological Standard Week (MSW) (i.e., August). The maximum population of defoliator, Spodoptera litura (Fab.) was noticed during 34th MSW. The higher populations of coccinellid beetles and spiders were recorded during 35th MSW while chrysopid activity was maximum during 36th MSW (September). During Rabi season, the sucking pests were active from October second week and attained peak during the second and third week of November. The maximum activity of aphids and leafhoppers was noticed during the 46th and 47th MSW (November), respectively. The highest incidence of thrips was recorded during the 48th MSW. The peak population of whiteflies and mites was recorded during the 46th and 45th MSW, respectively. The peak activity defoliator and shoot borer were noticed during the 45th and 46th MSW, respectively. The chrysopid activity was maximum during 46th and 47th MSW.

Numerical Investigation of the Fire Behavior of Storage Rack Systems Protected by Intumescent Coating.

Using a finite element strategy, this study investigates the behavior of beam-to-column connections in storage rack systems exposed to high temperatures. The purpose of this research was to develop moment–rotation (M–θ) curves after painting various structural members with varied configurations in order to evaluate the performance of intumescent-coated beams, uprights, and connectors, which are components of storage rack systems. Within the scope of this work, finite element analyses were carried out in two stages. First, thermal analyses were performed using the transient thermal analysis system of ANSYS Workbench software to estimate the ultimate temperatures of the beam, upright, and connector, which were painted with 1 mm thick paint and exposed to standard (ISO-834) fire. The results were then compared to the Eurocode 3 Part 1.2 with a satisfactory agreement. In the second stage of the analysis, a total of 9 possible alternative models were investigated in the static structural analysis system, reflecting the effect of applying fire protection to the different portions of the rack system. Since the most critical stress level is achieved around the connector tabs, it has been observed that protection of the connector in individual or binary conditions provides higher performance while protection of the beam causes divergent joint behavior. Additionally, comparison of fully protected and unprotected conditions presents an increment of more than 7% on the joint’s ultimate moment capacity and initial stiffness, which is an explicit contribution of the intumescent coating to fire resistance.

Estimation of avoidable yield losses in Indian mustard (Brassica juncea L.) due to mustard aphid, Lipaphis erysimi (Kaltenbach) in Rewari district, Haryana, India

The Indian mustard (Brassica juncea L.) is a significant oilseed crop in India. The sap-sucking pest, mustard aphid (Lipaphis erysimi) emerged as a major threat to this crop, which can harshly reduce yield. The research experiment was carried out during the Rabi seasons, 2019-20 and 2020-21 at Rewari, Haryana to comprehend the influence of L. erysimi infestation on different yield parameters of B. juncea in the field. The two cultivars of B. juncea namely, RH 725 and RB 50 were raised in a paired plot design with two different sets viz., protected and unprotected and thirteen replications each set were kept. The protected set was sprayed with insecticide Dimethoate 30 EC @ 625 ml ha-1 one time only, whereas unprotected set was kept free from insecticidal application for natural infestation of the pest. The present investigation revealed that under unprotected conditions, the yield parameters viz., weight of 100 siliquae, 100 siliquae husk, 10 main apical shoots (10 cm) and 1000 seeds, as well as seed yield, were significantly (P<0.01) affected by the L. erysimi infestation, while parameter, seed germination percentage influenced non-significantly (P>0.01). The maximum seed yield losses were registered in genotype RH 725 (26.25 %) when compared with RB 50 (25.92 %). All other yield parameters exhibited the same pattern except for three parameters i.e. weight of 100 siliquae, 100 siliquae husk and 10 main apical shoots (10 cm). In conclusion, this research highlights the colossal yield losses inflicted by L. erysimi infestation in B. juncea in unprotected conditions and the utility of insecticidal application in the enhancement of crop yield by management of this insect pest in protected conditions.

Estimation of crop losses in Cajanus cajan (L.) Millsp. and Vigna radiata (L.) Wilczek caused by blister beetle, Mylabris pustulata Thunberg (Coleoptera: Meloidae)

Losses caused by Mylabris pustulata Thunberg in pigeonpea and mungbean at various beetle densities were assessed under net house/caged and field conditions. The observations revealed that the blister beetle caused considerable crop losses to both the pigeonpea and mungbean crops as under net house conditions, M. pustulata Thunberg at 200 beetles/cage caused the maximum reduction of 54.18, 20.15 and 64.88 per cent in pod setting, seed setting and grain yield in pigeonpea, respectively. Similarly, in mungbean, M. pustulata Thunberg at 4 beetles/cage caused maximum reduction up to 67.14, 26.65 and 75.29 per cent in pod setting, seed setting and grain yield, respectively. However, under unprotected conditions, 46.77 and 35.90 per cent of yield losses were recorded in pigeonpea and mungbean, respectively as compared to 0% under protected conditions. Thus, justifying that M. pustulata Thunberg is a major threat to both pulse crops and needs to be managed efficiently to avoid the significant crop losses caused by it.

Numerical study of Articulated Concrete Mattresses (ACMs) for offshore pipeline protection

In offshore pipeline projects, inevitably long sections of the transportation pipeline network require protection from natural hazards. Under such environmental conditions, concrete mattresses are recognized as a well-proven technology to surpass challenges in offshore pipeline construction, umbilical deployment and seabed protection/stabilization. To have a better understanding of the physical process of Fluid–Structure–Seabed-Interactions (FSSI) with a ACMs–Pipe–Seabed system, a workable numerical model is proposed to simulate wave–current induced soil responses around the system. Based on the proposed model, this paper discusses the momentary seabed liquefaction near the offshore pipeline and the stability of ACMs. Numerical examples show that ACMs have a significant positive effect on preventing seabed liquefaction around the pipeline by pushing the liquefaction zone to both sides of the shaft. Compared with unprotected conditions, the instability of the protective layer is mainly concentrated in its edge area, and the liquefaction depth can be reduced by around half of the pipe diameter. For the double ACMs–Pipe-System, it is found that the stability of the nearby seabed foundation is related to the mattress spacing and interaction angle.

Yield loss assessment due to Alternaria blight disease in rapeseed and mustard: Yield loss due to alternaria Blight in rapeseed and mustard

Alternaria blight disease in rapeseed-mustard caused by Alternaria brassicae and A. brassicicola is the important disease of rapeseed-mustard crop in India. The experiment was conducted to assess the yield losses due to Alternaria blight in different released cultivars of rapeseed-mustard during Rabi 2016-17 and 2017-18 at Student’s Instructional Farm of the A. N. D. University of Agriculture and Technology, Kumarganj, Ayodhya by planting 15 varieties of the rapeseed-mustard namely RH-749, Pusa gold, KBS-3, GSL-5, GSL-2, Pusa mustard-27, Jhumka, Anuradha, PT-30, T-27, PM-25, Pusa aditya, PT-303, Sheetal, TMLC-2 in six replications (three protected and three unprotected under natural conditions). Seed of each variety were treated with Apron @ 6g/kg and three spray of Trifloxystrobin 25% + Tebuconazol 50% (Nativo) @ 0.08% in protected replication. The minimum disease severity on leaves and pods were recorded in protected and unprotected conditions in the variety GSL-5 (2.65% and 16.26%), (1.75% and 6.32%) followed by GSL-2 (3.20% and 19.72%), (1.89% and 6.75%) Pusa aditya (6.91% and 19.89%), (2.18% and 7.20%) and Sheetal (7.99% and 23.13%), (3.21% and 7.43%), respectively. On the basis of mean values the minimum infection rate on pods was recorded GSL-2 (0.083 and 0.042) followed by Pusa aditya (0.089 and 0.045), respectively. The minimum AUDPC on leaf under protected and unprotected was recorded on cultivar GSL-5 (76.40 and 496.20) followed by GSL-2 (88.80 and 596.85), Pusa aditya (205.35 and 588.25), Sheetal (241.70 and 717.30) and RH-749 (244.95 and 950.85), respectively. Whereas the minimum AUDPC on pod was recorded with variety GSL-5 (32.10) and Pusa aditya (200.25) followed by [GSL-2 (34.65) and Sheetal (206.65)], [Pusa aditya (39.35) and RH-749 (566.41)] and [Sheetal (60.95) and Pusa mustard-27 (741.75)], respectively. The maximum yield avoidable loss (%) was recorded T-27 (46.67%) followed by Jhumka (44.53%, Anuradha (40.00%), KBS-3 (38.77%) and Pusa gold (34.13%), respectively. Minimum avoidable loss (%) was recorded on cultivar GSL-5 (11.09%) followed by Anuradha (14.36%), GSL-2 (17.73%), RH-749 (17.90%) and Pusa aditya, respectively. In present investigation out of 15 genotypes examined for blight resistance, GSL-5, Pusa Aditya, Sheetal and GSL-2 exhibited good level of partial resistance i.e. moderately resistance. Other 11 varieties RH-749, Pusa gold, Pusa mustard-27, Jhumka, Anuradha, PT-30, PT-303, T-27, KBS-3, TMLC-2 and PM-25 were susceptible based on the mean basis severity (PDI), reduced apparent infection rate and lesser value of AUDPC.

Inconsistent relationships among protection, benthic assemblage, habitat complexity and fish biomass in Mediterranean temperate rocky reefs

Marine Protected Areas (MPAs) have been proved to effectively protect and restore fish assemblages. There is mixed evidence regarding the effects of MPAs on benthic assemblages, habitat complexity, and how protection might mediate the effects of habitat features (including biotic and abiotic components) on fish assemblages, with very little information concerning temperate areas. Here, our aim is to assess how protection 1) influences benthic assemblages and habitat complexity, and 2) mediates the effects of habitat complexity on fishes.Using non-destructive methods (photosampling for shallow rocky benthic assemblages, and underwater visual census using strip transects for fish assemblages) to characterize benthic and fish assemblages, we sampled 15 Mediterranean locations, each including protected and unprotected sites. In all, we sampled 90 sites, and analyzed 2,760 photos and 800 replicated transects, gathering information on 44 benthic and 72 fish taxa. Abiotic, biotic and synthetic (i.e. combining the previous two) complexity indices have been computed to synthesize habitat features. Overall, whole benthic assemblages did not significantly differ between protected and unprotected conditions, but higher cover of the ecologically important erect algae belonging to the genus Cystoseira sensu lato was recorded within MPAs. Abiotic, biotic and synthetic complexity did not show clear patterns related to protection levels, displaying inconsistent responses between different locations. Our findings highlight that protection has a generally positive effect on fish biomass, this latter variable responding independently of the habitat complexity.Our study, in conclusion, confirms that MPAs can be effective to protect and restore rocky-reef assemblages, highlighting the need for more in-depth exploration of the mechanisms determining the different responses of benthic taxa to protection and how this can influence the associated fish assemblages.

Experimental study of ISHTAR thermostatic irradiation device for the MARIA research reactor

Materials and core components for the next generation power reactors technologies require testing that can be performed in existing research reactors. Such experiments employ devices dedicated to reflect the relevant thermal and neutron parameters simulating conditions present in, for example, but not limited to, HTGR reactors. A novel thermostatic irradiation device named ISHTAR (Irradiation System for High-Temperature Reactors) has been designed and constructed in the MARIA research reactor. Its mission is to enable irradiation of samples in controlled, homogeneous temperature field reaching 1000°C and inert gas atmosphere. The high temperature is achieved by a combination of electric and gamma heating, together with carefully designed thermal insulation. Additionally, samples holder made of graphite with high thermal conductivity enables the temperature homogenization in all directions. Device will be placed inside the Beryllium matrix of MARIA core and cooled with forced circulation of water from the reactor pool loop. This paper presents the outcome of experiments conducted with the rig prototype in external hydraulic mock-up of the MARIA reactor irradiation channel. The results have proved that the desired conditions for irradiation of the samples were achieved and their comparison against computational data has shown the adequacy of the design process. Finally, the loss of flow scenario was tested in protected and unprotected conditions (meaning with and without the safety system based on temperature feedback), proving the operational safety of the ISHTAR design. Experimental results will be used in the future to validate the numerical models (two and three dimensional) of the irradiation rig, providing an improved understanding of free convection and radiation phenomena modeling.

Estimation of avoidable yield losses in chickpea caused by Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae)

The estimation of avoidable crop losses caused by Helicoverpa armigera (Hubner) infesting chickpea was carried out at Punjab Agricultural University, Ludhiana during rabi seasons, 2016–17 and 2017–18 using insect density (0, 1, 2, 3, 4, 5 and 6 larvae per meter row length), mechanical and chemical protection methods. Per cent avoidable losses were found to increase with increase in the larval infestation level. The highest and lowest avoidable crop loss of 73.50 and 17.5% was recorded in treatments with six and one larvae per meter row length, respectively. The correlation between the larval infestation level and the per cent pod damage was found to be significantly positive (r = 0.99). However, correlation between the larval infestation level and seed yield (kg ha−1) was significantly negative (r = −0.99). The per cent pod damage was 27.47 under unprotected plots as compared to 3.13 when protected; likewise, the mean numbers of pods per ten plants were 331.92 and 296.21 when the crop was chemically and mechanically protected, respectively as against 247.12 under unprotected conditions. Further, mean yield was 1841 and 1690 kg ha−1 under protected conditions in comparison to 1355 kg ha−1, when left unprotected. On the basis of yield, avoidable losses of 26.27 and 19.59% were recorded in chemical and mechanical protection treatment over the unprotected method, respectively. Hence, aim of the study was to first evaluate maximum avoidable yield losses at different larval densities and then to find the most effective method of protection that can help in avoiding crop losses which in turn will increase net returns of the farmers.

Correlation studies of sunflower Alternaria leaf blight with weather parameters

To assess the impact of weather conditions on the progress of Alternaria leaf blight in two cultivars KBHS-44and Morden of sunflower, an experiment was conducted during kharif 2013-14 and 2014-15. It was recorded that per cent disease index (PDI) was positively correlated with relative humidity during morning (RH1), relative humidity during evening (RH2), and with crop age for two cultivars. These correlations were found to be significant under protected and unprotected conditions. PDI was negatively correlated with temperature maximum significantly and also with rainy days, sunshine hours and wind velocity. But the effect of temperature minimum was not significant.

Protection reveals density-dependent dynamics in fish populations: A case study in the central Mediterranean.

Casting light on how the interaction between protection and density dependence affects fish population dynamics is critical for understanding the effectiveness of marine protected areas (MPAs). We developed a framework based on nonparametric statistics, model selection and multi-model inference to contrast alternative hypotheses about the effect of density dependence on demographic dynamics under protected and unprotected conditions. We trialed it using a 12-year long time series of white seabream (Diplodus sargus sargus) population density within the no-take zone of Torre Guaceto MPA (Italy) and at two nearby unprotected locations. Then, we showed how the demographic models obtained can be used to assess the consequences of protection on population viability. Population dynamics were significantly influenced by fish density within the MPA and at one of the unprotected locations, where demography is possibly driven by directional recruitment subsidy from the MPA. The comparison of population growth rates within and outside the MPA suggests that in unprotected conditions the fishery may remove a fraction between 40 and 70% of the population each year. The population viability analysis pointed out that, while the probability that the population becomes depleted (i.e. undergoes a local, temporary quasi-extinction) is high in unprotected locations, it is negligible within the no-take zone of the MPA.

The Hidden Hand of Domestic Labor: Domestic Employers' Work Practices in Chicago, USA

An emergent body of scholarly work exists regarding the manifold dimensions and implications of domestic work, scholarship which draws from various standpoints and discipline traditions. Much existing literature deals specifically with the devaluation of domestic labor. A recent survey conducted in 14 metropolitan areas in the U.S. found that the domestic work industry is profoundly ethnocentric, gendered and racialized, with 23% of domestic workers earning below their state's mandated minimum wage. In 42 states, it is legal to pay domestic workers below minimum wage, since they are explicitly excluded from the protections of key federal labor laws and standards. In addition, many studies have repeatedly denounced the persistent gendered division of labor in the industry, and in particular have raised concerns about the disproportionate number of women of color in this occupation. Finally, given the private nature of domestic work and the unprotected conditions workers face, studies have pointed to the frequent hostile or even abusive relationships that employers have with their employees. Despite the wealth of research on domestic labor, relatively few studies conducted in the US have focused on the practices of domestic employers. There is also a dearth of research on domestic employment located specifically in the Midwest. The lacuna in this research motivated us to conduct a preliminary study on Midwestern employers' practices, in particular in Chicago and the surrounding suburbs. We argue that overlooking domestic employers' work practices prevents us from tackling the situations of abuse and disrespect that so frequently occur in this particular work environment.

Force, impulse and energy during falling with and without knee protection: an in-vitro study

The mechanics of protective knee padding mitigating injury from a high-force fall have not been investigated in real-life scenarios to date. This study compares the effect of wearing knee pads to unprotected impact on a hard surface. We hypothesized that knee pads reduce the force and energy transmitted to the bony structures of the knee cap compared with unprotected conditions. Eight human knee cadaver specimens were embedded and fixed with a flexion angle of 100 degrees in a custom-made drop testing device (75 kg including the knee). The usage of a knee pad led to an average peak force attenuation on impact of 15% (no pad: 5932 N SD: 2472 N; pad: 4210 N SD: 2199 N; p < 0.001). Contact time on the plate was higher with a knee pad (no pad: 0.015 s SD: 0.009 s; pad: 0.028 s SD: 0.014 s; p < 0.001). Therefore, the observed impulse was also increased (no pad: 62.2 Ns SD: 17.8 Ns; pad: 74.6 Ns SD: 18.6 Ns; p < 0.001). This effect diminished as drop height was increased. Energy dissipation, defined as the difference between kinetic energy pre-impact and peak potential energy post-impact, was higher without a knee pad (no pad: 10.5 J SD: 6.2 J; pad: 4.2 J SD: 5.0 J; p < 0.001). The results from this study illustrate the magnitude of influence that knee pads have on peak forces, transmitted impulse, and energy transfer from a high-force impact in real-life scenarios. Contrary to expectations, the knee pad did not act as a mechanical damper. The mechanical behavior more closely resembled a spring that temporarily stores energy and consequentially reduces peak forces upon impact. Based on this study, future developments in padding might benefit from focusing on the aspect of energy storage and temporarily delayed energy dissipation.