Duration Of Various Phases Research Articles

Study of the Milkability of the Mediterranean Italian Buffalo and the Tunisian Maghrebi Camel According to Parity and Lactation Stage.

While considered as hard milkers, both buffaloes and camels are milked with equipment destined for dairy cows based on external morphological similarities with this species. This work aimed to study similarities and differences in milkability traits between Mediterranean buffaloes and Maghrebi she-camels and to evaluate the effect of parity and lactation stage. A total of 422 milk flow curves recorded with an electronic milkmeter (Lactocorder®) for both species were accessed. Milking characteristics including milk yield per milking, peak milk flow, average milk flow, duration of the main milking phase, duration of total milking, duration of various phases of milk flow, lag time and time to milk ejection, stripping yield, overmilking time and incidence of bimodal milk flow curves were evaluated for both species. Results showed that the values of milk yield per milking, duration of the main milking phase and duration of total milking were higher in buffaloes (3.98 ± 0.10 kg; 4.07 ± 0.11 min; 9.89 ± 0.21 min, respectively) compared to camels (3.51 ± 0.08 kg; 3.05 ± 0.09 min; 3.76 ± 0.09 min, respectively). However, camels had significantly higher peak and average milk flow (2.45 ± 0.07 kg/min and 1.16 ± 0.03 kg/min, respectively). Camels took significantly less time for milk ejection to occur. Only 15.49% of recorded curves were bimodal in buffaloes while 34.93% of bimodal curves were recorded for camels. Overmilking was significantly higher in buffaloes (3.64 ± 0.21 min vs. 0.29 ± 0.02 min). Parity and lactation stage had a significant effect on most studied milking traits suggesting the need for some particular practices with primiparous animals and animals at different levels of lactation for both species.

The effect of different sowing dates on dry matter and nitrogen dynamics for winter wheat: an experimental simulation study.

BackgroundTimely sowing is an important agronomic measure to ensure the normal germination, stable seedling establishment, and yield formation for winter wheat (Triticum aestivum L.). Delayed sowing frequently occurs in the current multi-cropping system and mechanized production of this crop. However, the ways in which different sowing dates affect yield and its potential mechanism is still unknown in the middle-lower Yangtze River Basin. We sought to provide a theoretical basis for these mechanisms to improve regional wheat production.MethodsWe investigated the wheat’s yield differences in a two-year field study under different sowing dates and took into account related growth characteristics including meteorological conditions, growth period, tillers, dry matter accumulation (DMA), and nitrogen accumulation (NA). We used the logistic curve model to simulate DMA and NA dynamics of single stem wheat under different sowing dates. We then analyzed and compared wheat accumulation for different sowing dates.ResultsOur results showed that grain yield declined by 0.97 ± 0.22% with each one-day change (either early or delayed) in sowing beyond the normal sowing date. The yield loss could be explained by the inhibition of crop growth, yield components, biomass and nitrogen (N) production. The negative effects of delayed sowing were caused by environmental limitations including adverse weather factors such as low temperature during vegetative growth, shortened duration of various phases of crop development, and increased temperature during the grain-filling period. The grain yield gap decreased between the late and normal sowing periods owing to a compensatory effect between the highest average rates (Vt) and the rapid accumulation period (T) of DMA and NA for single stem wheat. The grain yield was maintained at 6,000 kg ha−1 or more when the ratio of DMA at the mature-to-jointing stage (MD/JD) and the ratio of NA at the mature-to-jointing stage (MN/JN) was 4.06 (P < 0.01) and 2.49 (P < 0.05), respectively. The compensatory effect did not prevent the impact caused by delayed sowing, which caused biomass and N production to decrease. Physiological development reached a maximal accumulation rate (Tm) of NA earlier than DMA.

Yield penalty due to delayed sowing of winter wheat and the mitigatory role of increased seeding rate

Abstract Timely sowing is an important agronomic practice that ensures normal seed germination, stable seedling establishment and final yield formation for winter wheat (Triticum aestivum L.). However, delays in sowing frequently occur due to uncontrollable limitations, especially under multi–cropping. Increased seeding rate is recommended to minimize the negative impacts associated with delayed sowing, but the underlying mechanism is still unclear. A 4–year field study was conducted under winter wheat–maize (Zea mays L.) double–cropping system to determine the grain yield penalty and grain quality deterioration due to delayed sowing of winter wheat and to evaluate the potential compensatory role of increased seeding rate. The results showed that grain yield declined by 1% for each day that sowing date was delayed. Such yield penalty could be mainly explained in terms of suppression of crop growth, yield components, leaf area index (LAI) and biomass production. The reduction in yield–determining attributes was mainly caused by some key environmental limitations, i.e., adverse weather factors such as low temperature during crop vegetative growth, shortened duration of various phases of crop development, and elevated temperature during the grain–filling period. Grain protein and starch content were both increased and milled flour (%) was reduced significantly with delayed sowing. Increased seeding rate completely mitigated the yield loss for a one–week delay in sowing and partially compensated for the two–week delay in sowing. For delays in sowing of more than two weeks, increased seeding rate failed to compensate for the yield penalty. Such failure can be explained by the lack in efficiency of increased plant population under higher seeding rate to compensate for reduced biomass production, LAI and grain number under delayed sowing. Other more effective mitigatory options such as varietal selection and development that could sustain high yield even under delayed sowing should be considered for extended delays of winter wheat.

Reliability Assessment of IGBT Through Modelling and Experimental Testing

Lifetime of power electronic devices, in particular those used for wind turbines, is short due to the generation of thermal stresses in their switching device e.g., IGBT particularly in the case of high switching frequency. This causes premature failure of the device leading to an unreliable performance in operation. Hence, appropriate thermal assessment and implementation of associated mitigation procedure are required to put in place in order to improve the reliability of the switching device. This paper presents two case studies to demonstrate the reliability assessment of IGBT. First, a new driving strategy for operating IGBT based power inverter module is proposed to mitigate wire-bond thermal stresses. The thermal stress is characterised using finite element modelling and validated by inverter operated under different wind speeds. High-speed thermal imaging camera and dSPACE system are used for real time measurements. Reliability of switching devices is determined based on thermoelectric (electrical and/or mechanical) stresses during operations and lifetime estimation. Second, machine learning based data-driven prognostic models are developed for predicting degradation behaviour of IGBT and determining remaining useful life using degradation raw data collected from accelerated aging tests under thermal overstress condition. The durations of various phases with increasing collector-emitter voltage are determined over the device lifetime. A data set of phase durations from several IGBTs is trained to develop Neural Network (NN) and Adaptive Neuro Fuzzy Inference System (ANFIS) models, which is used to predict remaining useful life (RUL) of IGBT. Results obtained from the presented case studies would pave the path for improving the reliability of IGBTs.

Anticonvulsant effects of nimodipine alone and combination with phenytoin on MES induced seizures

Background: To evaluate the anticonvulsant activity of Nimodipine alone and in combination with Phenytoin, in MES induced seizures.Methods: The study was conducted in mice and MES seizure was induced by Techno electroconvulsometer. In first part of study, animals were treated with Nimodipine (20mg/kg i.p. and 40mg/kg i.p.) and Phenytoin (0.5 mg/100g i.p. and 1.0mg/100g i.p.), MES was induced and durations of various phases were noted. Duration of Tonic hind limb extension (THLE) was taken as index for antiepileptic activity. In second part, the animals were treated with combination of sub effective doses of Nimodipine (20mg/kg i.p.) and Phenytoin (0.5mg/100g i.p.), MES was induced and durations of various phases were noted.Results: Nimodipine produced significant antiepileptic activity, in dose dependent manner. Phenytoin produced significant antiepileptic effect in dose of 1.0mg/100g but failed to produce any such effect in dose of 0.5mg/100g, when administered alone. But when sub effective doses.Of Nimodipine and Phenytoin were combined, a synergistic effect was seen.Conclusions: Nimodipine possess significant antiepileptic activity, alone, as well as it potentiates the antiepileptic effect of Phenytoin, suggesting the novel application of already proven safe and efficacious calcium channel blockers.

ANTICONVULSANT EFFECTS OF NIMODIPINE ALONE AND COMBINATION WITH PHENYTOIN ON MES INDUCED SEIZURES

Objective: To evaluate the anticonvulsant activity of Nimodipine alone and in combination with Phenytoin, in MES induced seizures.Methods: The study was conducted in mice and MES seizure was induced by Techno electro-convulsometer. In the first part of the study, animals were treated with Nimodipine (20 mg/kg i. p. and 40 mg/kg i. p.) and Phenytoin (0.5 mg/100g i. p. and 1.0 mg/100g i. p.), MES was induced and durations of various phases were noted. Duration of Tonic hindlimb extension (THLE) was taken as an index for antiepileptic activity. In the second part, the animals were treated with a combination of sub effective doses of Nimodipine (20 mg/kg i. p.) and Phenytoin (0.5 mg/100g i. p.), MES was induced and durations of various phases were noted.Results: Nimodipine produced significant antiepileptic activity, in a dose-dependent manner. Phenytoin produced a significant antiepileptic effect in dose of 1.0 mg/100g, but failed to produce any such effect in a dose of 0.5 mg/100g, when administered alone. But when sub-effective doses. Of Nimodipine and Phenytoin were combined, a synergistic effect was seen.Conclusion: Nimodipine posses significant antiepileptic activity, alone, as well as it potentiates the antiepileptic effect of Phenytoin, suggesting the novel application of already proven safe and efficacious calcium channel blockers.

ANTICONVULSANT EFFECTS OF NIFEDIPINE ON MES INDUCED SEIZURES

Objective: To evaluate the anticonvulsant activity of Nifedipine against MES induced seizures.Methods: The study was induced by techno electroconvulsometer. The animals were treated with Nifedipine (100 μg/100 g i. p. and 200 μg/100 g i. p.) and MES was induced 2 h after the administration of the drug, and duration of various phases was noted. Duration of THLE was taken as an index for antiepileptic activity.Results: Nifedipine when administered in a dose of 100 μg/100 g ip, did not produce any changes in any phases of the MES induced seizure. But in a dose of 200 μg/100 g ip, it significantly reduced the duration of THLE.Conclusion: Nifedipine has a significant action against MES induced seizures suggesting an important role of CCBs as future, promising antiepileptic drug.

Anticonvulsive effects of nifedipine and flunarizine on maximal electroshock seizures induced seizures

Background: Epilepsy is a common neurological disorder but the mechanism of seizure generation has been only partially unraveled. Currently available antiepileptics have a low therapeutic index and furthermore, provide satisfactory seizures control in only 60–70% of patients. Therefore, the present study was done to review the basic mechanism of seizures with special attention on voltage gated calcium channels and search for new antiepileptic in order to improve the efficacy of current therapies. Aims and Objective: The current study aimed to evaluate the anticonvulsant activity of calcium channel blockers. Materials and Methods: The animals were treated with Nifedipine (100 μg/100 g ip and 200 μg/100 g ip) and Flunarizine (5mg ⁄ kg ip and 10 mg⁄kg ip) and maximal electroshock seizures (MES) was induced by technoelectro convulsometer, 2 hrs after the administration of drugs, and duration of various phases were noted. Duration of tonic hind limb extension (THLE) was taken as index for antiepileptic activity. Result: Nifedipine and Flunarizine when administered in dose of 100 μg/100 g ip and 5 mg/kg respectively did not produce any changes in any phases of the MES induced seizure. But in dose of 200 μg/100 g ip and 10 mg/kg ip respectively, it significantly reduced the duration of THLE. Conclusion: Nifedipine and Flunarizine have a significant action against MES induced seizures suggesting an important role of CCBs as future, promising antiepileptic drug.

Effects of short-term training on behavioral learning and skill acquisition during intraoral fine motor task

Sensory information from the orofacial mechanoreceptors are used by the nervous system to optimize the positioning of food, determine the force levels, and force vectors involved in biting of food morsels. Moreover, practice resulting from repetition could be a key to learning and acquiring a motor skill. Hence, the aim of the experiment was to test the hypothesis that repeated splitting of a food morsel during a short-term training with an oral fine motor task would result in increased performance and optimization of jaw movements, in terms of reduction in duration of various phases of the jaw movements. Thirty healthy volunteers were asked to intraorally manipulate and split a chocolate candy, into two equal halves. The participants performed three series (with 10 trials) of the task before and after a short-term (approximately 30min) training. The accuracy of the split and vertical jaw movement during the task were recorded. The precision of task performance improved significantly after training (22% mean deviation from ideal split after vs. 31% before; P<0.001). There was a significant decrease in the total duration of jaw movements during the task after the training (1.21 s total duration after vs. 1.56 s before; P<0.001). Further, when the jaw movements were divided into different phases, the jaw opening phase and contact phase were significantly shorter after training than before training (P=0.001, P=0.002). The results indicate that short-term training of an oral fine motor task induces behavior learning, skill acquisition and optimization of jaw movements in terms of better performance and reduction in the duration of jaw movements, during the task. The finding of the present study provides insights into how humans learn oral motor behaviors or the kind of adaptation that takes place after a successful prosthetic rehabilitation.

Antiepileptic and central nervous system depressant activity of &lt;i&gt;Sechium edule&lt;/i&gt; fruit extract

The effect of ethanol extract of fruits of Sechium edule on antiepileptic and central nervous system (CNS) depressant model was studied in rats. The extract (200 mg/kg body weight, orally) significantly reduced the duration of various phases of convulsions in both MES-induce seizures and in PTZ-induced convulsion. In CNS depressant model, the locomotor activity was also decreased in a dose dependent manner as compared to control group the extract and the rota rod test revealed a significant loss of muscular coordination.

Anti Epileptic Activity of Morinda citrifolia Linn Fruit Extract

Fruit extract of Morinda citrifolia (Noni), a medicinal plant used in many neuro protective ayurvedic preparations was evaluated for its protective effect against seizures induced by Maximal Electro Shock (MES) method in rats. A daily dose of 200 and 400 mg/kg of the extract was administered to the animals for 15 days, after which seizures were induced by maximum electro shock method and the duration of various phases of epileptic attacks were recorded and compared with the control animals. A significant (P&lt;0.01 and P&lt;0.001) reduction in the time taken for righting reflex (recovery) was noted in the experimental animals. The levels of biogenic amines such as dopamine, serotonin and nor‐adrenaline in the forebrain region were also estimated and a significant level of restoration was opserved in the extract treated animals. Significant results were opserved in the estimated parameters thereby justifying the use of this medicinal plant in the treatment of epilepsy.

Anti Epileptic Activity of Poly Herbal Extract from Indian Medicinal Plants

With the introduction of allopathic drugs, the use of crude drugs from medicinal plants is on the decline and subsequently this traditional knowledge may be lost in the near future. In the present study, a poly herbal extract comprising of Withania somnifera Dunal, a medicinal plant used in many neuro protective Ayurvedic preparations along with five other medicinal plants were evaluated for its protective effect against seizures induced by Maximal Electro shock (MES) method in rats. A daily dose of 250 and 500 mg/kg of the extract was administered to the animals for 15 days, after which seizures were induced by Maximum electro shock method and the duration of various phases of epileptic attacks were recorded and compared with the control animals. A significant (P &lt; 0.01 and P &lt; 0.001) reduction in the time taken for righting reflex (recovery) was noted in the experimental animals. The levels of biogenic amines such as dopamine, serotonin and nor-adrenaline in the forebrain region were also estimated and a significant level of restoration was observed in the extract treated animals. Significant results were observed in the estimated parameters thereby justifying the use of these medicinal plants in the treatment of epilepsy. Keywords: Anti epileptic activity; Biogenic amines; Maximal Electro Shock; Poly herbal extract; Seizures. ©2009 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v1i1.1057Â

The interdecadal trend and shift of dry/wet over the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO)

Based on monthly precipitation and monthly mean surface air temperature (SAT), the dry/wet trends and shift of the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO) from 1951 to 2005 have been analyzed through calculating surface wetness index (SWI). The results indicate that there was a prominent drying trend and an abrupt change in the analysis period. A persistent warming period with less precipitation from the mid and late 1970s to present was found, and a shift process exists from the wet to the dry in the central part of North China during 1951–2005. The transition is located in the mid to late 1970s, which should be related to the shift variation of large-scale climate background. The correlation analysis has brought about a finding of significant correlativity between PDO index (PDOI) and SAT, precipitation and SWI in this region. The correlation exhibits that the positive phase of PDOI (warm PDO phase) matches warming, less precipitation and the drought period, and the negative PDOI phase corresponds to low SAT, more precipitation and the wet period. The duration of various phases is more than 25 years. The decadal variation of sea surface temperature (SST) in the North Pacific Ocean is one of the possible causes in forming the decadal dry/wet trend and shift of the central part of North China.

The mating and reproductive biology of the freshwater planktonic calanoid copepod Eudiaptomus gracilis

1. Quantitative aspects of the mating and reproductive biology of the freshwater planktonic calanoid copepod Eudiaptomus gracilis, including duration and frequency of mating, duration of various phases of the oviducal cycle, egg production rate and adult longevity were studied under laboratory conditions. One set of copepods was fed the alga Chlamydomonas reinhardtii whose density was adjusted to 2 × 105 cells mL−1 (about 10 mg C L−1), another set was fed a mixed diet consisting of natural plankton (copepod nauplii, small rotifers and large algae) in the size range of 50–150 μm (dry mass approximately 90 mg L−1).2. The entire mating process, from the grasping of the female by the male’s right geniculate antennule to the separation of the pair, lasted about 2 min. Spermatophore placement started at about 30 s to 1 min after mating began and took approximately 1 min. Immediately after the spermatophore had been fixed in the female’s genital segment, the pair separated.3. The total oviducal cycle, including the gravid phase where the female carried ripe oocytes and the non‐gravid phase where the female did not carry ripe oocytes, lasted about 5–6 days. The non‐gravid phase was particularly long; it was longer than the gravid phase and constituted 62–72% of the total cycle.4. Mating and spermatophore placement usually occurred with gravid females although occasionally (in 30 of 200 observations) spermatophores were attached in the genital segment of non‐gravid females. Generally two to four, but up to seven, spermatophores were observed at a female’s genital segment at the same time.5. Clutch size, rate of egg production and adult longevity depended on food. When fed on C. reinhardtii, females carried 7–8 eggs clutch−1, produced a mean of 1.3 clutches and lived 14 days on average. When fed natural mixed food, females carried 10 eggs clutch−1, produced 5.6 clutches and lived 37 days on average.6. Removal of males after the first clutch resulted in no further egg production. Re‐mating is necessary in E. gracilis for continuous clutch production and the production of fertile eggs.7. Mating duration is comparatively short and the non‐gravid phase comparatively long in E. gracilis. This could be an adaption to the life in the pelagic zone of the lake, where fish predators are present. Fish select ovigerous females, pairs in copula and, probably, females with ripe oocytes which make them conspicuous. Thus, a short mating duration and a prolonged period without conspicuous oocytes, can be advantageous.

Cell Cycle Kinetics in Rat Prostatic Epithelia: Nuclear Migration During G2 Phase

Proliferative events in luminal epithelial cells of the rat ventral prostate were studied in 2 experiments. In experiment 1 a longitudinal survey of the rat prostate was conducted between 22 and 88 days of age. The pattern of temporal changes in the weight of the ventral prostate paralleled that of the testis, an observation consistent with the knowledge that the prostate is an androgen target organ. However, the total number of mitotic cells per prostate showed a biphasic pattern of distribution. The count was high (82 per prostate) in the prostate of 22-day-old rats and it decreased to a low value (25 per prostate) by age 30 days, a period corresponding to the onset of puberty in rats. The total mitotic count per prostate increased gradually and reached a peak (85 per prostate) around age 60 days when it started to decline gradually despite a continuous increase in prostatic weight.In experiment 2 cell cycle parameters of these cells were determined in young adult rats (age 70 days or 250gm. body weight) by an in vivo 3H-thymidine pulse-chase approach. The apparent duration of various phases of the cell cycle was estimated as G1—11.5hours, S—6.5hours, G2—3.0hours, M—2.0hours and total cell cycle—23hours. The fraction of cells in the S phase was 2.1%, which was extrapolated to give rise to a total growth fraction of 7.4%. In addition, it was noted that there was a migration of the nucleus from the base toward the apex of the epithelial cells during the G2 phase of the cell cycle in preparation for cell mitosis. Following mitosis nuclei of the 2 daughter cells returned to the usual basal position. These parameters will be used as basis of our future kinetic studies in the rat prostate.

Behavioral Responses of Male Trichoplusia ni in a Sustained-Flight Tunnel to the Two Sex Pheromone Components

Male Trichoplusia ni were tested individually in a sustained-flight tunnel to different amounts and ratios of the two sex pheromone components, ( Z )-7-dodecenyl acetate ( Z 7-12:Ac) and dodecyl acetate (12:Ac). The primary component, Z7-12:Ac, was responsible for activation and initiation of upwind oriented flight. The secondary component, 12:Ac, elicited no behavioral response when presented alone. When 12:Ac was combined with Z7-l2:Ac in the natural blend, 93:7 Z7-l2:Ac and 12:Ac, at the optimum dosage tested, the number of upwind flights to the source, the duration of close range flight, contact and attempted copulations with the source were significantly higher than in response to Z7-l2:Ac alone. Males exhibited individual variation in duration of various phases of the response, but no significant dosage effects were observed with respect to initiation of activation or duration of wing fanning and upwind flight in moths that flew to within 25 cm of the source.

Haemodynamics in the horse: 3. Duration of the phases of the cardiac cycle.

The paper reports observations on the duration of various phases of the cardiac cycle using a bipole ECG record as a time base from which to measure the timing of pressure changes in the chambers of the heart and great vessels. From the findings the likely sequence of mechanical events during the cardiac cycle in the atria and ventricles is described.

Thymic Lymphopoiesis and Cell Loss in Newborn Mice

Abstract Thymic lymphopoiesis in 2 day old Swiss albino mice (Hale-Stoner strain) was studied autoradiographically based on the variation of mitotic labeling indices and intensities after a single intraabdominal injection of 3H-thymidine. Best estimates for the duration of various phases of the generative cell cycle are as follows: G2 for the majority of cells: 86-94 minutes, shortest possible duration for a small fraction of cells: 35-48 minutes; mitosis: 27-44 minutes; DNA synthesis: 7 hours; generation time: 9¼ hours. G1 could not be determined directly by the methods used but probably is short. The present data do not indicate different generation times for proliferating thymic lymphoid cells of unequal size although the very largest elements must be excluded from this statement because of rare occurrence. The results obtained in this study together with data on changes of thymic weight and proliferative activity in the neonatal period indicate that during the third day after birth, a fraction corresponding to one third of all lymphoid cells present in the organ at the end of this period is lost. In view of the extremely low pyknotic index in the thymus at this age, the present data provide support in favor of an extensive emigration of lymphoid cells being the major cause of this cell loss.