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All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

ESPC ESA Webinar Series: ESPC ENABLE Contract Vehicle Overview

This webinar provides instructions and resources for financing distributed energy projects (e.g. on-site renewable energy, storage, and combined heat and power) using an energy savings performance contract (ESPC) energy sales agreement (ESA) through the U.S. Department of Energy's (DOE) ESPC ENABLE contract vehicle. The ESPC ENABLE contract vehicle is a streamlined procurement process that uses a standard investment grade audit tool and standard contract templates. Topics covered in the webinar include: An overview of the ESPC ENABLE contract vehicle; ESA-specific considerations for ENABLE contracts; and Case studies. This webinar also provides an overview of the resources available on the Federal Energy Management Program website, such as ESPC ENABLE templates. This webinar is the fourth of a series that provides information, best practices, and resources for implementing an ESPC ESA project. ESPC ESAs are a great option for federal sites that are motivated to reduce site costs, have no capital investment funding, and cannot use the U.S. Department of Defense 10 USC 2922a authority for long-term contracting.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2012

The effect of DDT and its metabolite (DDE) on prostaglandin secretion from epithelial cells and on contractions of the smooth muscle of the bovine oviduct in vitro

The insecticide DDT and its metabolite (DDE), due to their lipolytic nature and resistance to biodegradation, are accumulated in the living tissues. In cows, DDT and DDE were found to affect prostaglandin (PG) secretion from the endometrium and contractions of the myometrium. In this study, the impact of both xenobiotics (0.1, 1, 10 or 100 ng/ml) on the function of epithelial cells and muscle strips of bovine oviducts from 1 to 5 day of the oestrous cycle was examined. Therefore the concentration of PGE2 and PGFM (a metabolite of PGF2α) in culture media, mRNA expression of genes involved in PGs synthesis in epithelial cells and the force and amplitude of strips contractions were measured after 2 and 24 or 48 h of incubation. Neither DDT nor DDE affected the viability of cells after 48 h (P > 0.05). Both DDT and DDE increased the concentrations of PGFM in culture medium and secretion of PGE2 after only 2 h of cell culture (P < 0.05). Similar effects were seen for the influence of DDE on amount of PGFM after 48 h, while DDT decreased secretion of PGE2 (P < 0.05). DDT after 2 h increased (P < 0.05) mRNA expression of PGF2α synthase (PGFS), while both xenobiotics decreased (P < 0.05) mRNA expression of cyclooxygenase-2 (COX-2) after 24 h. DTT also increased the force of isthmus contractions after 2 h, as did both xenobiotics after 48 h (P < 0.05). Moreover, after 2 and 48 h, DDE stimulated the amplitude of contractions of the isthmus as well as the ampulla, (P < 0.05). The effect of both compounds on oviduct contractions was diminished by indomethacin, which blocks PG synthesis. We conclude that oviductal secretion of prostaglandins is affected, by DDT and DDE. The influence of these xenobiotics on PGF2α and PGE2 secretion and ratio may be part of the mechanism by which both DDT and its metabolite disturb the contractions of oviductal muscle. -- Highlights: ► DDT and its metabolite – DDE are accumulated in the living tissues. ► The insecticides affected PGF2α and PGE2 release from epithelial cells of oviduct. ► They also stimulated markedly the contractions of oviductal strips. ► Prostaglandins were involved in the effect of insecticides on oviduct function.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

A Communication-Optimal Framework for Contracting Distributed Tensors

Tensor contractions are extremely compute intensive generalized matrix multiplication operations encountered in many computational science fields, such as quantum chemistry and nuclear physics. Unlike distributed matrix multiplication, which has been extensively studied, limited work has been done in understanding distributed tensor contractions. In this paper, we characterize distributed tensor contraction algorithms on torus networks. We develop a framework with three fundamental communication operators to generate communication-efficient contraction algorithms for arbitrary tensor contractions. We show that for a given amount of memory per processor, our framework is communication optimal for all tensor contractions. We demonstrate performance and scalability of our framework on up to 262,144 cores of BG/Q supercomputer using five tensor contraction examples.

communication efficiency↗
DOE OSTI2024

Total Power Factor Smart Contract with Cyber Grid Guard Using Distributed Ledger Technology for Electrical Utility Grid with Customer-Owned Wind Farm

In modern electrical grids, the numbers of customer-owned distributed energy resources (DERs) have increased, and consequently, so have the numbers of points of common coupling (PCC) between the electrical grid and customer-owned DERs. The disruptive operation of and out-of-tolerance outputs from DERs, especially owned DERs, present a risk to power system operations. A common protective measure is to use relays located at the PCC to isolate poorly behaving or out-of-tolerance DERs from the grid. Ensuring the integrity of the data from these relays at the PCC is vital, and blockchain technology could enhance the security of modern electrical grids by providing an accurate means to translate operational constraints into actions/commands for relays. This study demonstrates an advanced power system application solution using distributed ledger technology (DLT) with smart contracts to manage the relay operation at the PCC. The smart contract defines the allowable total power factor (TPF) of the DER output, and the terms of the smart contract are implemented using DLT with a Cyber Grid Guard (CGG) system for a customer-owned DER (wind farm). This article presents flowcharts for the TPF smart contract implemented by the CGG using DLT. The test scenarios were implemented using a real-time simulator containing a CGG system and relay in-the-loop. The data collected from the CGG system were used to execute the TPF smart contract. The desired TPF limits on the grid-side were between +0.9 and +1.0, and the operation of the breakers in the electrical grid and DER sides was controlled by the relay consistent with the provisions of the smart contract. The events from the real-time simulator, CGG, and relay showed a successful implementation of the TPF smart contract with CGG using DLT, proving the efficacy of this approach in general for implementing electrical grid applications for utilities with connections to customer-owned DERs.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2013

THE CONTRACTION OF OVERLYING CORONAL LOOP AND THE ROTATING MOTION OF A SIGMOID FILAMENT DURING ITS ERUPTION

We present an observation of overlying coronal loop contraction and rotating motion of the sigmoid filament during its eruption on 2012 May 22 observed by the Solar Dynamics Observatory (SDO). Our results show that the twist can be transported into the filament from the lower atmosphere to the higher atmosphere. The successive contraction of the coronal loops was due to a suddenly reduced magnetic pressure underneath the filament, which was caused by the rising of the filament. Before the sigmoid filament eruption, there was a counterclockwise flow in the photosphere at the right feet of the filament and the contraction loops and a convergence flow at the left foot of the filament. The hot and cool materials have inverse motion along the filament before the filament eruption. Moreover, two coronal loops overlying the filament first experienced brightening, expansion, and contraction successively. At the beginning of the rising and rotation of the left part of the filament, the second coronal loop exhibited rapid contraction. The top of the second coronal loop also showed counterclockwise rotation during the contraction process. After the contraction of the second loop, the left part of the filament rotated counterclockwise and expanded toward the right of NOAA AR 11485. During the filament expansion, the right part of the filament also exhibited counterclockwise rotation like a tornado.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Optimizing Tensor Contractions in CCSD(T) for Efficient Execution on GPUs

Tensor contractions are higher dimensional analogs of matrix multiplications, used in many computational contexts such as high order models in quantum chemistry, deep learning, nite element methods etc. In contrast to the wide availability of high-performance libraries for matrix multiplication on GPUs, the same is not true for tensor contractions. In this paper, we address the optimization of a set of symmetrized tensor contractions that form the computational bottleneck in the CCSD(T) coupled-cluster method in computational chemistry suites like NWChem. Some of the challenges in optimizing tensor contractions that arise in practice from the variety of dimensionalities and shapes for tensors include effective mapping of the high-dimensional iteration space to threads, choice of data buffering in shared-memory and registers, and tile sizes for multi-level tiling. Furthermore, in the case of symmetrized tensor contractions in CCSD(T), it is also a challenge to fuse contractions to reduce data movement cost by exploiting reuse of intermediate tensors. In this paper, we developed an efficient GPU implementation of the tensor contractions in CCSD(T) using shared-memory buffering, register tiling, loop fusion and register transpose. Experimental results demonstrate significant improvement over the current state-of-the-art.

Kim, Jinsung↗
DOE OSTI2023

Graph Contractions for Calculating Correlation Functions in Lattice QCD

Computing correlation functions for many-particle systems in Lattice QCD is vital to extract nuclear physics observables like the energy spectrum of hadrons such as protons. However, this type of calculation has long been considered to be very challenging and computing-resource intensive because of the complex nature of a hadron composed of quarks with many degrees of freedom. In particular, a correlation function can be calculated through a sum of all possible pairs of quark contractions, each of which is a batched tensor contraction, dictated by Wick's theorem. Because the number of terms of this sum can be very large for any hadronic system of interest, fast evaluation of the sum faces several challenges: an extremely large number of contractions, a huge memory footprint at runtime, and the speed of tensor contractions. In this paper, we present a Lattice QCD analysis software suite, Redstar, which addresses these challenges by utilizing novel algorithmic and software engineering methods targeting modern computing platforms such as many-core CPUs and GPUs. In particular, Redstar represents every term in the sum of a correlation function by a graph, applies efficient graph algorithms to reduce the number of contractions to lower the cost of computations, and minimizes the total memory footprint. Moreover, Redstar carries out the contractions on either CPUs or GPUs utilizing an internal and highly efficient Hadron contraction library. Specifically, we illustrate some important algorithmic optimizations of Redstar, show various key design features of Hadron library, and present the speedup values due to the optimizations along with performance figures for calculating six correlations functions on four computing platforms.

Chen, Jie↗
DOE OSTI2023

Graph Contractions for Calculating Correlation Functions in Lattice QCD

Computing correlation functions for many-particle systems in Lattice QCD is vital to extract nuclear physics observables like the energy spectrum of hadrons such as protons. However, this type of calculation has long been considered to be very challenging and computing-resource intensive because of the complex nature of a hadron composed of quarks with many degrees of freedom. In particular, a correlation function can be calculated through a sum of all possible pairs of quark contractions, each of which is a batched tensor contraction, dictated by Wick's theorem. Because the number of terms of this sum can be very large for any hadronic system of interest, fast evaluation of the sum faces several challenges: an extremely large number of contractions, a huge memory footprint at runtime, and the speed of tensor contractions. In this paper, we present a Lattice QCD analysis software suite, Redstar, which addresses these challenges by utilizing novel algorithmic and software engineering methods targeting modern computing platforms such as many-core CPUs and GPUs. In particular, Redstar represents every term in the sum of a correlation function by a graph, applies efficient graph algorithms to reduce the number of contractions to lower the cost of computations, and minimizes the total memory footprint. Moreover, Redstar carries out the contractions on either CPUs or GPUs utilizing an internal and highly efficient Hadron contraction library. Specifically, we illustrate some important algorithmic optimizations of Redstar, show various key design features of Hadron library, and present the speedup values due to the optimizations along with performance figures for calculating six correlations functions on four computing platforms.

Chen, Jie↗
NASA NTRS1980

The effect of finite turbulence spatial scale on the amplification of turbulence by a contracting stream

The turbulence downstream of a rapid contraction is calculated for the case when the turbulence scale can have the same magnitude as the mean-flow spatial scale. The approach used is based on the formulation of Goldstein (1978) for turbulence downstream of a contraction, with the added assumptions of a parallel mean flow at downstream infinity and turbulence calculated far enough downstream so that the nonuniformity of the mean flow field has decayed, and by treating the inverse contraction ratio as a small parameter. Consideration is given to the large-contraction-ratio and classical rapid-distortion theory limits, and to results at an arbitrary contraction ratio. It is shown that the amplification effect of the contraction is reduced when the spatial scale of the turbulence increases, with the upstream turbulence actually suppressed for a contraction ratio less than five and a turbulence spatial scale greater than three times the transverse dimensions of the downstream channel.

Goldstein, M. E.↗
NASA NTRS1988

Contraction design for small low-speed wind tunnels

An iterative design procedure was developed for 2- or 3-dimensional contractions installed on small, low speed wind tunnels. The procedure consists of first computing the potential flow field and hence the pressure distributions along the walls of a contraction of given size and shape using a 3-dimensional numerical panel method. The pressure or velocity distributions are then fed into 2-dimensional boundary layer codes to predict the behavior of the boundary layers along the walls. For small, low speed contractions, it is shown that the assumption of a laminar boundary layer originating from stagnation conditions at the contraction entry and remaining laminar throughout passage through the successful designs is justified. This hypothesis was confirmed by comparing the predicted boundary layer data at the contraction exit with measured data in existing wind tunnels. The measured boundary layer momentum thicknesses at the exit of four existing contractions, two of which were 3-D, were found to lie within 10 percent of the predicted values, with the predicted values generally lower. From the contraction wall shapes investigated, the one based on a 5th order polynomial was selected for newly designed mixing wind tunnel installation.

Bell, James H.↗
NASA NTRS1988

Contraction design for small low-speed wind tunnels

An iterative design procedure was developed for two- or three-dimensional contractions installed on small, low-speed wind tunnels. The procedure consists of first computing the potential flow field and hence the pressure distributions along the walls of a contraction of given size and shape using a three-dimensional numerical panel method. The pressure or velocity distributions are then fed into two-dimensional boundary layer codes to predict the behavior of the boundary layers along the walls. For small, low-speed contractions it is shown that the assumption of a laminar boundary layer originating from stagnation conditions at the contraction entry and remaining laminar throughout passage through the successful designs if justified. This hypothesis was confirmed by comparing the predicted boundary layer data at the contraction exit with measured data in existing wind tunnels. The measured boundary layer momentum thicknesses at the exit of four existing contractions, two of which were 3-D, were found to lie within 10 percent of the predicted values, with the predicted values generally lower. From the contraction wall shapes investigated, the one based on a fifth-order polynomial was selected for installation on a newly designed mixing layer wind tunnel.

Bell, James H.↗
NASA NTRS2000

Limb congestion enhances the synchronization of sympathetic outflow with muscle contraction

In this report, we examined if the synchronization of muscle sympathetic nerve activity (MSNA) with muscle contraction is enhanced by limb congestion. To explore this relationship, we applied signal-averaging techniques to the MSNA signal obtained during short bouts of forearm contraction (2-s contraction/3-s rest cycle) at 40% maximal voluntary contraction for 5 min. We performed this analysis before and after forearm venous congestion; an intervention that augments the autonomic response to sustained static muscle contractions via a local effect on muscle afferents. There was an increased percentage of the MSNA noted during second 2 of the 5-s contraction/rest cycles. The percentage of total MSNA seen during this particular second increased from minute 1 to 5 of contraction and was increased further by limb congestion (control minute 1 = 25.6 +/- 2.0%, minute 5 = 32.8 +/- 2.2%; limb congestion minute 1 = 29.3 +/- 2.1%, minute 5 = 37.8 +/- 3.9%; exercise main effect <0.005; limb congestion main effect P = 0.054). These changes in the distribution of signal-averaged MSNA were seen despite the fact that the mean number of sympathetic discharges did not increase over baseline. We conclude that synchronization of contraction and MSNA is seen during short repetitive bouts of handgrip. The sensitizing effect of contraction time and limb congestion are apparently due to feedback from muscle afferents within the exercising muscle.

Non-NASA Center↗
NASA NTRS1999

Physiological response to submaximal isometric contractions of the paravertebral muscles

STUDY DESIGN: Brief (30-second) isometric trunk extensions at 5%, 20%, 40%, 60%, and 80% of maximal voluntary contraction (MVC) and 3 minutes of prolonged trunk extension (20% MVC) in erect position were studied in nine healthy male subjects. OBJECTIVES: To investigate the intercorrelation between intramuscular pressure and tissue oxygenation of the paravertebral muscles during submaximal isometric contractions and further, to evaluate paravertebral electromyogram and intramuscular pressure as indicators of force development. SUMMARY OF BACKGROUND DATA: Local physiologic responses to muscle contraction are incompletely understood. METHODS: Relative oxygenation was monitored with noninvasive near-infrared spectroscopy, intramuscular pressure was measured with a transducer-tipped catheter, and surface electromyogram was monitored at three recording sites. RESULTS: The root mean square amplitudes of the paravertebral electromyogram (L4, left and right; T12, right) and intramuscular pressure measured in the lumbar multifidus muscle at L4 increased with greater force development in a curvilinear manner. A significant decrease in the oxygenation of the lumbar paravertebral muscle in response to muscle contraction was found at an initial contraction level of 20% MVC. This corresponded to a paravertebral intramuscular pressure of 30-40 mm Hg. However, during prolonged trunk extension, no further decrease in tissue oxygenation was found compared with the tissue oxygenation level at the end of the brief contractions, indicating that homeostatic adjustments (mean blood pressure and heart rate) over time were sufficient to maintain paravertebral muscle oxygen levels. CONCLUSION: At a threshold intramuscular pressure of 30-40 mm Hg during muscle contraction, oxygenation in the paravertebral muscles is significantly reduced. The effect of further increase in intramuscular pressure on tissue oxygenation over time may be compensated for by an increase in blood pressure and heart rate. Surface electromyogram amplitudes and intramuscular pressure can be used as indicators of paravertebral muscle force.

NASA Center ARC↗
DOE OSTI2019

Panel Session 68: Small Business Procurement and Contracting Opportunities Within the DOE Complex and USACE FUSRAP Program

This panel session was held in the Panel Zone in the Exhibit Hall and focused on small business procurement and contracting opportunities within the DOE Complex as well as the US Army Corps of Engineers (USACE) National Formerly Utilized Sites Remedial Action Program (FUSRAP) projects. Each panelist provided a general overview of their respective organization, small business goals and the success in meeting those goals. They further discussed recently awarded procurement, upcoming opportunities and provided additional contact information for individual small business program managers within their organization. This panel was open to all WM participants, including Exhibitors. This panel session focused on small business procurement and contracting opportunities within the DOE Complex and the USACE FUSRAP Program. The DOE and USACE contract directly with small businesses and encourage prime contractors to obtain goods and services from small and disadvantaged businesses (Tier 2) and often tie these goals to contract award fee. Goods and services being considered for these procurements include decontamination and decommissioning, remediation, transportation and disposal of radioactive waste, health physics, emergency response planning and training, lab services, R and D products, waste treatment, maintenance, A/E and professional consulting. This panel complemented Session 21 and Session 48, US DOE Spring Quarterly Forum, and Session 88 on Doing Business with the DOE. Presentations proposed include: 1 - Small Business Procurement and Contracting Opportunities Within the DOE Complex (Aaron Deckard, US DOE (USA)); 2 - Small Business Procurement and Contracting Opportunities Within the DOE Complex (William Badger, AECOM (USA)); 3 - Engineering the Extraordinary (Lisa Tribuce-Leoung Tat, Bechtel National, Inc. (USA)); 4 - Fluor Small Business Procurement and Contracting Opportunities (Debra Sampson, Fluor Government Group (USA)); 5 - HII Technical Solutions Division Small Business Opportunities (Kela Lofton, HII Nuclear Inc. (USA)); 6 - U. S. Army Corps of Engineers Radiological Remediation Work (Nicki Fatherly, USACE (USA))

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Optimizing multiple reliable forward contracts for reservoir allocation using multitime scale streamflow forecasts

Streamflow forecasts at multiple time scales provide a new opportunity for reservoir management to address competing objectives. Market instruments such as forward contracts with specified reliability are considered as a tool that may help address the perceived risk associated with the use of such forecasts in lieu of traditional operation and allocation strategies. A water allocation process that enables multiple contracts for water supply and hydropower production with different durations, while maintaining a prescribed level of flood risk reduction, is presented. The allocation process is supported by an optimization model that considers multitime scale ensemble forecasts of monthly streamflow and flood volume over the upcoming season and year, the desired reliability and pricing of proposed contracts for hydropower and water supply. It solves for the size of contracts at each reliability level that can be allocated for each future period, while meeting target end of period reservoir storage with a prescribed reliability. The contracts may be insurable, given that their reliability is verified through retrospective modeling. The process can allow reservoir operators to overcome their concerns as to the appropriate skill of probabilistic forecasts, while providing water users with short–term and long–term guarantees as to how much water or energy they may be allocated. An application of the optimization model to the Bhakra Dam, India, provides an illustration of the process. In conclusion, the issues of forecast skill and contract performance are examined. A field engagement of the idea is useful to develop a real–world perspective and needs a suitable institutional environment.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Optimal contracting structure between cellulosic biorefineries and farmers to reduce the impact of biomass supply variation: game theoretic analysis

There is considerable year–to–year variability in the supply of cellulosic biomass used in the production of cellulosic biofuels, yet strategies to mitigate these variations in biofuel development are not well understood. Biorefineries and farmers venturing into the cellulosic biofuel industry will require biomass supply and contracting strategies that can minimize the impact of these large variations. Some studies have proposed biomass pre–treatment and storage to address biomass supply variations. Other studies have used transportation modeling approaches to manage supply variations and select the optimal location of a cellulosic biorefinery. However, storage, pre–treatment, and similar engineering approaches lead to higher costs and have other limitations such as additional infrastructural requirements. There is a gap in understanding how contracting strategies between biorefineries and the biomass suppliers (farmers) can reduce the risks with biomass supply variations. In this study, the contracting structure between biorefineries and biomass suppliers is studied under different market structures for the US Corn Belt. A theoretical framework is then developed to use contracting strategies for mitigating the impact of biomass supply variations. First, the trade–offs between intricately linked components of biomass cost, such as biomass transport, biomass price (incentive) to suppliers, variation in biomass supply, biorefinery size, and alternative feedstock availability are examined. Next, an optimal contracting structure is developed between biorefineries and biomass suppliers using game theoretic analysis. Here, the results show that both the impact of biomass supply variations and the overall biomass cost can be significantly reduced through the use of the optimal contracting strategy between biorefineries and suppliers.

cellulosic biofuel↗
DOE OSTI2015

The adverse effects of aldrin and dieldrin on both myometrial contractions and the secretory functions of bovine ovaries and uterus in vitro

Aldrin and dieldrin are chloroorganic insecticides which are recognised as endocrine disruptors. The aim of the study was to investigate their effect on the secretory functions of the uterus and ovary and on myometrial contractions. Myometrial strips and uterine and ovarian cells from nonpregnant cows were incubated with the xenobiotics (0.1, 1 or 10 ng/ml) for 24 or 72 h. Next, their effect on viability of myometrial, endometrial, granulosa and luteal cells, myometrial strip contractions, the synthesis and secretion of prostaglandins (PGs: PGF2α and PGE2) from uterine cells, the secretion of oestradiol (E2), testosterone (T) and oxytocin (OT) from granulosa cells and the secretion of progesterone (P4) and OT from luteal cells were determined. Neither of the xenobiotics (10 ng/ml) affected (P > 0.05) the viability of the ovarian and uterine cells, while both (0.1–10 ng/ml) decreased (P < 0.05) the basal and OT-stimulated myometrial contractions. In spite of these effects, neither of the insecticides affected (P > 0.05) the synthesis and the secretion of PGs from the myometrial cells. Although they also did not impair the secretion of the PGs from the endometrial cells, they abolished (P < 0.05) the stimulatory effect of OT (P < 0.05) on the secretion of the PGs and stimulated (P < 0.05) the secretion of OT from the granulosa and luteal cells. Moreover, aldrin and dieldrin stimulated secretion of E2 and T from the granulosa cells, while only dieldrin increased (P < 0.05) the secretion of P4 from luteal cells. The data show that aldrin and dieldrin stimulated the secretory function of the cultured granulosa and luteal cells and inhibited the myometrial contractions of cows in vitro, which may affect on natural parturition. - Highlights: • Aldrin and dieldrin inhibited bovine myometrial contractions. • The studied xenobiotics stimulated steroids and oxytocin secretion from ovaries. • Prostaglandins are not involved in adverse effect of the xenobiotics on uterine contractions. • On this basis, we believe that aldrin and dieldrin can hinder the course and onset of parturition.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Secretory function of ovarian cells and myometrial contractions in cow are affected by chlorinated insecticides (chlordane, heptachlor, mirex) in vitro

The aim of the study was to investigate the effect of chlordane, heptachlor and mirex, on hormonal regulation of the force of myometrial contractions. Myometrial, endometrial, granulosa and luteal cells as well as strips of myometrium from non-pregnant cows were incubated with three insecticides at environmentally relevant doses (0.1, 1 or 10 ng/ml). None of the insecticides affected the viability of studied cells. Chlordane stimulated, while heptachlor and mirex inhibited, secretion of testosterone and estradiol from granulosa cells as well as secretion of progesterone from luteal cells, respectively. Secretion of oxytocin (OT) from granulosa cells was increased after incubation with all studied insecticides. Only mirex stimulated OT secretion from luteal cells, while heptachlor inhibited this effect. None of them affected synthesis of OT in luteal cells and prostaglandins (PGF2 and PGE2) secretion from uterine cells, except PGE2 secretion from endometrial cells was decreased when the cells were incubated with 0.1 ng/ml of chlordane. Basal and OT-stimulated myometrial contractions were increased by mirex and decreased by heptachlor. The data show that the insecticides altered secretory function of ovarian cells. Heptachlor and mirex affected also myometrial contractions in vitro, but uterine secretion of prostaglandins were not involved in the mechanism of that adverse effect of insecticides. The data indicate on potential of these insecticides to disturb fertilisation, blastocyst implantation or even the length of gestation. - Highlights: • The studied insecticides affected steroids and oxytocin secretion from ovaries. • Mirex stimulated bovine myometrial contractions. • Heptachlor inhibited bovine myometrial contractions. • Prostaglandins are not involved in adverse effect of the insecticides on uterine contractions.

60 APPLIED LIFE SCIENCES↗