Neonatal handling induces anovulatory estrous cycles in rats

Since previous work has shown that stimulation early in life decreases sexual receptiveness as measured by the female lordosis quotient, we suggested that neonatal handling could affect the function of the hypothalamus-pituitary-gonadal axis. The effects of neonatal handling on the estrous cycle and ovulation were analyzed in adult rats. Two groups of animals were studied: intact (no manipulation, N = 10) and handled (N = 11). Pups were either handled daily for 1 min during the first 10 days of life or left undisturbed. At the age of 90 days, a vaginal smear was collected daily at 9:00 a.m. and analyzed for 29 days; at 9:00 a.m. on the day of estrus, animals were anesthetized with thiopental (40 mg/kg, ip), the ovaries were removed and the oviduct was dissected and squashed between 2 glass slides. The number of oocytes of both oviductal ampullae was counted under the microscope. The average numbers for each phase of the cycle (diestrus I, diestrus II, proestrus and estrus) during the period analyzed were compared between the two groups. There were no significant differences between intact and handled females during any of the phases. However, the number of handled females that showed anovulatory cycles (8 out of 11) was significantly higher than in the intact group (none out of 10). Neonatal stimulation may affect not only the hypothalamus-pituitary-adrenal axis, as previously demonstrated, but also the hypothalamus-pituitary-gonadal axis in female rats.

Effect of inhibition of nitric oxide synthase on blood pressure and renal sodium handling in renal denervated rats

The role of sympathetic nerve activity in the changes in arterial blood pressure and renal function caused by the chronic administration of NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, was examined in sham and bilaterally renal denervated rats. Several studies have demonstrated that sympathetic nerve activity is elevated acutely after L-NAME administration. To evaluate the role of renal nerve activity in L-NAME-induced hypertension, we compared the blood pressure response in four groups (N = 10 each) of male Wistar-Hannover rats weighing 200 to 250 g: 1) sham-operated vehicle-treated, 2) sham-operated L-NAME-treated, 3) denervated vehicle-treated, and 4) denervated L-NAME-treated rats. After renal denervation or sham surgery, one control week was followed by three weeks of oral administration of L-NAME by gavage. Arterial pressure was measured weekly in conscious rats by a tail-cuff method and renal function tests were performed in individual metabolic cages 0, 7, 14 and 21 days after the beginning of L-NAME administration. L-NAME (60 mg kg-1 day-1) progressively increased arterial pressure from 108 ± 6.0 to 149 ± 12 mmHg (P<0.05) in the sham-operated group by the third week of treatment which was accompanied by a fall in creatinine clearance from 336 ± 18 to 222 ± 59 µl min-1 100 g body weight-1 (P<0.05) and a rise in fractional urinary sodium excretion from 0.2 ± 0.04 to 1.62 ± 0.35% (P<0.05) and in sodium post-proximal fractional excretion from 0.54 ± 0.09 to 4.7 ± 0.86% (P<0.05). The development of hypertension was significantly delayed and attenuated in denervated L-NAME-treated rats. This was accompanied by a striking additional increase in fractional renal sodium and potassium excretion from 0.2 ± 0.04 to 4.5 ± 1.6% and from 0.1 ± 0.015 to 1.21 ± 0.37%, respectively, and an enhanced post-proximal sodium excretion compared to the sham-operated group. These differences occurred despite an unchanged creatinine clearance and Na+ filtered load. These results suggest that bilateral renal denervation delayed and attenuated the L-NAME-induced hypertension by promoting an additional decrease in tubule sodium reabsorption in the post-proximal segments of nephrons. Much of the hypertension caused by chronic NO synthesis inhibition is thus dependent on renal nerve activity.

Neonatal handling and the expression of immunoreactivity to tyrosine hydroxylase in the hypothalamus of adult male rats

Neonatal handling has long-lasting effects on behavior and stress reactivity. The purpose of the present study was to investigate the effect of neonatal handling on the number of dopaminergic neurons in the hypothalamic nuclei of adult male rats as part of a series of studies that could explain the long-lasting effects of neonatal stimulation. Two groups of Wistar rats were studied: nonhandled (pups were left undisturbed, control) and handled (pups were handled for 1 min once a day during the first 10 days of life). At 75-80 days, the males were anesthetized and the brains were processed for immunohistochemistry. An anti-tyrosine hydroxylase antibody and the avidin-biotin-peroxidase method were used. Tyrosine hydroxylase-immunoreactive (TH-IR) neurons were counted bilaterally in the arcuate, paraventricular and periventricular nuclei of the hypothalamus in 30-µm sections at 120-µm intervals. Neonatal handling did not change the number of TH-IR neurons in the arcuate (1021 ± 206, N = 6; 1020 ± 150, N = 6; nonhandled and handled, respectively), paraventricular (584 ± 85, N = 8; 682 ± 62, N = 9) or periventricular (743 ± 118, N = 7; 990 ± 158, N = 7) nuclei of the hypothalamus. The absence of an effect on the number of dopaminergic cells in the hypothalamus indicates that the reduction in the amount of neurons induced by neonatal handling, as shown by other studies, is not a general phenomenon in the brain.

Gender differences in vascular expression of endothelin and ET A/ET B receptors, but not in calcium handling mechanisms, in deoxycorticosterone acetate-salt hypertension

We determined if the increased vascular responsiveness to endothelin-1 (ET-1) observed in male, but not in female, DOCA-salt rats is associated with differential vascular mRNA expression of ET-1 and/or ET A/ET B receptors or with functional differences in Ca2+ handling mechanisms by vascular myocytes. Uninephrectomized male and female Wistar rats received DOCA and drinking water containing NaCl/KCl. Control rats received vehicle and tap water. Blood pressure and contractile responses of endothelium-denuded aortic rings to agents which induce Ca2+ influx and/or its release from internal stores were measured using standard procedures. Expression of mRNA for ET-1 and ET A/ET B receptors was evaluated by RT-PCR after isolation of total cell RNA from both aorta and mesenteric arteries. Systolic blood pressure was higher in male than in female DOCA rats. Contractions induced by Bay K8644 (which activates Ca2+ influx through voltage-operated L-type channels), and by caffeine, serotonin or ET-1 in Ca2+-free buffer (which reflect Ca2+ release from internal stores) were significantly increased in aortas from male and female DOCA-salt compared to control aortas. DOCA-salt treatment of male, but not female, rats statistically increased vascular mRNA expression of ET-1 and ET B receptors, but decreased the expression of ET A receptors. Molecular up-regulation of vascular ET B receptors, rather than differential changes in smooth muscle Ca2+ handling mechanisms, seems to account for the increased vascular reactivity to ET-1/ET B receptor agonists and higher blood pressure levels observed in male DOCA-salt rats.

Genesis and Evolution of Brittle Structures In Southwestern Finland and Western South Africa. Insights into Fault Reactivation, Fluid Flow and Structural Maturity in Precambrian Cratons

The bedrock of old crystalline cratons is characteristically saturated with brittle structures formed during successive superimposed episodes of deformation and under varying stress regimes. As a result, the crust effectively deforms through the reactivation of pre-existing structures rather than by through the activation, or generation, of new ones, and is said to be in a state of 'structural maturity'. By combining data from Olkiluoto Island, southwestern Finland, which has been investigated as the potential site of a deep geological repository for high-level nuclear waste, with observations from southern Sweden, it can be concluded that the southern part of the Svecofennian shield had already attained structural maturity during the Mesoproterozoic era. This indicates that the phase of activation of the crust, i.e. the time interval during which new fractures were generated, was brief in comparison to the subsequent reactivation phase. Structural maturity of the bedrock was also attained relatively rapidly in Namaqualand, western South Africa, after the formation of first brittle structures during Neoproterozoic time. Subsequent brittle deformation in Namaqualand was controlled by the reactivation of pre-existing strike-slip faults.In such settings, seismic events are likely to occur through reactivation of pre-existing zones that are favourably oriented with respect to prevailing stresses. In Namaqualand, this is shown for present day seismicity by slip tendency analysis, and at Olkiluoto, for a Neoproterozoic earthquake reactivating a Mesoproterozoic fault. By combining detailed field observations with the results of paleostress inversions and relative and absolute time constraints, seven distinctm superimposed paleostress regimes have been recognized in the Olkiluoto region. From oldest to youngest these are: (1) NW-SE to NNW-SSE transpression, which prevailed soon after 1.75 Ga, when the crust had sufficiently cooled down to allow brittle deformation to occur. During this phase conjugate NNW-SSE and NE-SW striking strike-slip faults were active simultaneous with reactivation of SE-dipping low-angle shear zones and foliation planes. This was followed by (2) N-S to NE-SW transpression, which caused partial reactivation of structures formed in the first event; (3) NW-SE extension during the Gothian orogeny and at the time of rapakivi magmatism and intrusion of diabase dikes; (4) NE-SW transtension that occurred between 1.60 and 1.30 Ga and which also formed the NW-SE-trending Satakunta graben located some 20 km north of Olkiluoto. Greisen-type veins also formed during this phase. (5) NE-SW compression that postdates both the formation of the 1.56 Ga rapakivi granites and 1.27 Ga olivine diabases of the region; (6) E-W transpression during the early stages of the Mesoproterozoic Sveconorwegian orogeny and which also predated (7) almost coaxial E-W extension attributed to the collapse of the Sveconorwegian orogeny. The kinematic analysis of fracture systems in crystalline bedrock also provides a robust framework for evaluating fluid-rock interaction in the brittle regime; this is essential in assessment of bedrock integrity for numerous geo-engineering applications, including groundwater management, transient or permanent CO2 storage and site investigations for permanent waste disposal. Investigations at Olkiluoto revealed that fluid flow along fractures is coupled with low normal tractions due to in-situ stresses and thus deviates from the generally accepted critically stressed fracture concept, where fluid flow is concentrated on fractures on the verge of failure. The difference is linked to the shallow conditions of Olkiluoto - due to the low differential stresses inherent at shallow depths, fracture activation and fluid flow is controlled by dilation due to low normal tractions. At deeper settings, however, fluid flow is controlled by fracture criticality caused by large differential stress, which drives shear deformation instead of dilation.

Routine post-weaning handling of rats prevents isolation rearing-induced deficit in prepulse inhibition

Rats reared under isolation conditions from weaning present a number of behavioral changes compared to animals reared under social conditions (group housing). These changes include deficits in prepulse inhibition (PPI) of the startle reflex to a loud sound. PPI refers to the reduction of the magnitude of the startle reflex when a relatively weak stimulus (the prepulse) precedes by an appropriate time interval the intense startle-elicing stimulus (the pulse). PPI is useful for studying sensorimotor integration. The present study evaluated the effect of handling on the impairment of PPI induced by isolation-rearing. Male Wistar rats (N = 11-15/group) were housed in groups (5 per cage and handled three times a week) or isolated (housed individually) since weaning (21 days) for 10 weeks when they reach approximately 150 g. The isolated rats were divided into "minimally handled" animals (handled once a week for cleaning purposes only) or "handled" animals (handled three times a week). This handling consisted of grasping the rat by the tail and moving it to a clean cage (approximately 5 s). A statistically significant reduction (52%) in the PPI test was found only in the isolated group with minimal handling while no difference was seen between grouped animals and isolated handled animals. These results indicate that isolation rearing causes disruption in the PPI at adult age, which serves as an index of attention deficit. This change in the sensory processing of information induced by post-weaning isolation can be prevented by handling during the development of the animal.

Effect of intraperitoneally administered hydrolyzed whey protein on blood pressure and renal sodium handling in awake spontaneously hypertensive rats

The present study evaluated the acute effect of the intraperitoneal (ip) administration of a whey protein hydrolysate (WPH) on systolic arterial blood pressure (SBP) and renal sodium handling by conscious spontaneously hypertensive rats (SHR). The ip administration of WPH in a volume of 1 ml dose-dependently lowered the SBP in SHR 2 h after administration at doses of 0.5 g/kg (0.15 M NaCl: 188.5 ± 9.3 mmHg vs WPH: 176.6 ± 4.9 mmHg, N = 8, P = 0.001) and 1.0 g/kg (0.15 M NaCl: 188.5 ± 9.3 mmHg vs WPH: 163.8 ± 5.9 mmHg, N = 8, P = 0.0018). Creatinine clearance decreased significantly (P = 0.0084) in the WPH-treated group (326 ± 67 µL min-1 100 g body weight-1) compared to 0.15 M NaCl-treated (890 ± 26 µL min-1 100 g body weight-1) and captopril-treated (903 ± 72 µL min-1 100 g body weight-1) rats. The ip administration of 1.0 g WPH/kg also decreased fractional sodium excretion to 0.021 ± 0.019% compared to 0.126 ± 0.041 and 0.66 ± 0.015% in 0.15 M NaCl and captopril-treated rats, respectively (P = 0.033). Similarly, the fractional potassium excretion in WPH-treated rats (0.25 ± 0.05%) was significantly lower (P = 0.0063) than in control (0.91 ± 0.15%) and captopril-treated rats (1.24 ± 0.30%), respectively. The present study shows a decreased SBP in SHR after the administration of WPH associated with a rise in tubule sodium reabsorption despite an angiotensin I-converting enzyme (ACE)-inhibiting in vitro activity (IC50 = 0.68 mg/mL). The present findings suggest a pathway involving ACE inhibition but measurements of plasma ACE activity and angiotensin II levels are needed to support this suggestion.

Biofuel handling, pretreatment and traffic use in China

This paper describes the development situation of biofuel in China and the research progress and application in transportation and aviation area, including several key technologies of biofuel production: biofuel pretreatment and handling. This paper is aiming to find the best storing, transmitting, feeding and pretreating methods of various materials, as well as a comparison among the advantages and disadvantages of different pretreatment methods, which is expected to reduce cost in production process and reach the maximized benefits. Meanwhile, a case study of one biomass fuel production factory in China is presented with evaluation and analysis on their technology application.

Obesity induces upregulation of genes involved in myocardial Ca2+ handling

Obesity is a complex multifactorial disorder that is often associated with cardiovascular diseases. Research on experimental models has suggested that cardiac dysfunction in obesity might be related to alterations in myocardial intracellular calcium (Ca2+) handling. However, information about the expression of Ca2+-related genes that lead to this abnormality is scarce. We evaluated the effects of obesity induced by a high-fat diet in the expression of Ca2+-related genes, focusing the L-type Ca2+ channel (Cacna1c), sarcolemmal Na+/Ca2+ exchanger (NCX), sarcoplasmic reticulum Ca2+ ATPase (SERCA2a), ryanodine receptor (RyR2), and phospholamban (PLB) mRNA in rat myocardium. Male 30-day-old Wistar rats were fed a standard (control) or high-fat diet (obese) for 15 weeks. Obesity was defined as increased percent of body fat in carcass. The mRNA expression of Ca2+-related genes in the left ventricle was measured by RT-PCR. Compared with control rats, the obese rats had increased percent of body fat, area under the curve for glucose, and leptin and insulin plasma concentrations. Obesity also caused an increase in the levels of SERCA2a, RyR2 and PLB mRNA (P < 0.05) but did not modify the mRNA levels of Cacna1c and NCX. These findings show that obesity induced by high-fat diet causes cardiac upregulation of Ca2+ transport_related genes in the sarcoplasmic reticulum.

Gentle handling temporarily increases c-Fos in the substantia nigra pars compacta

Dopaminergic neurotransmission is involved in the regulation of sleep. In particular, the nigrostriatal pathway is an important center of sleep regulation. We hypothesized that dopaminergic neurons located in substantia nigra pars compacta (SNpc) could be activated by gentle handling, a method to obtain sleep deprivation (SD). Adult male C57/BL6J mice (N = 5/group) were distributed into non-SD (NSD) or SD groups. SD animals were subjected to SD once for 1 or 3 h by gentle handling. Two experiments were performed. The first determined the activation of SNpc neurons after SD, and the second examined the same parameters after pharmacologically induced dopaminergic depletion using intraperitoneal reserpine (2 mg/kg). After 1 or 3 h, SD and NSD mice were subjected to motor evaluation using the open field test. Immediately after the behavioral test, the mice were perfused intracardially to fix the brain and for immunohistochemical analysis of c-Fos protein expression within the SNpc. The open field test indicated that SD for 1 or 3 h did not modify motor behavior. However, c-Fos protein expression was increased after 1 h of SD compared with the NSD and 3-h SD groups. These immunohistochemistry data indicate that these periods of SD are not able to produce dopaminergic supersensitivity. Nevertheless, the increased expression of c-Fos within the SNpc suggests that dopaminergic nigral activation was triggered by SD earlier than motor responsiveness. Dopamine-depleted mice (experiment 2) exhibited a similar increase of c-Fos expression compared to control animals indicating that dopamine neurons are still activated in the 1-h SD group despite the exhaustion of dopamine. This finding suggests that this range (2-5-fold) of neuronal activation may serve as a marker of SD.

Consequences of cerebroventricular insulin injection on renal sodium handling in rats: effect of inhibition of central nitric oxide synthase

In the present study, we investigated the effects of acute intracerebroventricular (icv) insulin administration on central mechanisms regulating urinary sodium excretion in simultaneously centrally NG-nitro-L-arginine methylester (L-NAME)-injected unanesthetized rats. Male Wistar-Hannover rats were randomly assigned to one of five groups: a) icv 0.15 M NaCl-injected rats (control, N = 10), b) icv dose-response (1.26, 12.6 and 126 ng/3 µL) insulin-injected rats (N = 10), c) rats icv injected with 60 µg L-NAME in combination with NaCl (N = 10) or d) with insulin (N = 10), and e) subcutaneously insulin-injected rats (N = 5). Centrally administered insulin produced an increase in urinary output of sodium (NaCl: 855.6 ± 85.1 Δ%/min; 126 ng insulin: 2055 ± 310.6 Δ%/min; P = 0.005) and potassium (NaCl: 460.4 ± 100 Δ%/min; 126 ng insulin: 669.2 ± 60.8 Δ%/min; P = 0.025). The urinary sodium excretion response to icv 126 ng insulin microinjection was significantly attenuated by combined administration of L-NAME (126 ng insulin: 1935 ± 258.3 Δ%/min; L-NAME + 126 ng insulin: 582.3 ± 69.6 Δ%/min; P = 0.01). Insulin-induced natriuresis occurred by increasing post-proximal sodium excretion, despite an unchanged glomerular filtration rate. Although the rationale for decreased urinary sodium excretion induced by combined icv L-NAME and insulin administration is unknown, it is tempting to suggest that perhaps one of the efferent signals triggered by insulin in the CNS may be nitrergic in nature.

The influence of high cable penetration in distribution networks on earth fault currents and the operation of relay protection.

Recent Storms in Nordic countries were a reason of long power outages in huge territories. After these disasters distribution networks' operators faced with a problem how to provide adequate quality of supply in such situation. The decision of utilization cable lines rather than overhead lines were made, which brings new features to distribution networks. The main idea of this work is a complex analysis of medium voltage distribution networks with long cable lines. High value of cable’s specific capacitance and length of lines determine such problems as: high values of earth fault currents, excessive amount of reactive power flow from distribution to transmission network, possibility of a high voltage level at the receiving end of cable feeders. However the core tasks was to estimate functional ability of the earth fault protection and the possibility to utilize simplified formulas for operating setting calculations in this network. In order to provide justify solution or evaluation of mentioned above problems corresponding calculations were made and in order to analyze behavior of relay protection principles PSCAD model of the examined network have been created. Evaluation of the voltage rise in the end of a cable line have educed absence of a dangerous increase in a voltage level, while excessive value of reactive power can be a reason of final penalty according to the Finish regulations. It was proved and calculated that for this networks compensation of earth fault currents should be implemented. In PSCAD models of the electrical grid with isolated neutral, central compensation and hybrid compensation were created. For the network with hybrid compensation methodology which allows to select number and rated power of distributed arc suppression coils have been offered. Based on the obtained results from experiments it was determined that in order to guarantee selective and reliable operation of the relay protection should be utilized hybrid compensation with connection of high-ohmic resistor. Directional and admittance based relay protection were tested under these conditions and advantageous of the novel protection were revealed. However, for electrical grids with extensive cabling necessity of a complex approach to the relay protection were explained and illustrated. Thus, in order to organize reliable earth fault protection is recommended to utilize both intermittent and conventional relay protection with operational settings calculated by the use of simplified formulas.

Variable-speed-drive-based detection methods for problems in fluid handling systems

Fluid handling systems account for a significant share of the global consumption of electrical energy. They also suffer from problems, which reduce their energy efficiency and increase life-cycle costs. Detecting or predicting these problems in time can make fluid handling systems more environmentally and economically sustainable to operate. In this Master’s Thesis, significant problems in fluid systems were studied and possibilities to develop variable-speed-drive-based detection methods for them was discussed. A literature review was conducted to find significant problems occurring in fluid handling systems containing pumps, fans and compressors. To find case examples for evaluating the feasibility of variable-speed-drive-based methods, queries were sent to industrial companies. As a result of this, the possibility to detect heat exchanger fouling with a variable-speed drive was analysed with data from three industrial cases. It was found that a mass flow rate estimate, which can be generated with a variable speed drive, can be used together with temperature measurements to monitor a heat exchanger’s thermal performance. Secondly, it was found that the fouling-related increase in the pressure drop of a heat exchanger can be monitored with a variable speed drive. Lastly, for systems where the flow device is speed controlled with by a pressure measurement, it was concluded that increasing rotational speed can be interpreted as progressing fouling in the heat exchanger.

Remote Observation of Radioactive Permit-Required Confined Spaces – Case: Posiva Oy’s Fuel Handling Cell

Posiva Oy’s final disposal facility’s encapsulation plant will start to operate in the 2020s. Once the operation starts, the facility is designed to run more than a hundred years. The encapsulation plant will be first of its kind in the world, being part of the solution to solve a global issue of final disposal of nuclear waste. In the encapsulation plant’s fuel handling cell the spent nuclear fuel will be processed to be deposited into the Finnish bedrock, into ONKALO. In the fuel handling cell, the environment is highly radioactive forming a permit-required enclosed space. Remote observation is needed in order to monitor the fuel handling process. The purpose of this thesis is to map (Part I) and compare (Part II) remote observation methods to observe Posiva Oy’s fuel handling cell’s process, and provide a possible theoretical solution for this case. Secondary purpose for this thesis is to provide resources for other remote observation cases, as well as to inform about possible future technology to enable readiness in the design of the encapsulation plant. The approach was to theoretically analyze the mapped remote observation methods. Firstly, the methods were filtered by three environmental challenges. These are the high levels of radiation, the permit-required confined space and the hundred year timespan. Secondly, the most promising methods were selected by the experts designing the facility. Thirdly, a customized feasibility analysis was created and performed on the selected methods to rank the methods with scores. The results are the mapped methods and the feasibility analysis scores. The three highest scoring methods were radiation tolerant camera, fiberscope and audio feed. A combination of these three methods was given as a possible theoretical solution for this case. As this case is first in the world, remote observation methods for it had not been thoroughly researched. The findings in this thesis will act as initial data for the design of the fuel handling cell’s remote observation systems and can potentially effect on the overall design of the facility by providing unique and case specific information. In addition, this thesis could provide resources for other remote observation cases.