1,250 research outputs found

    An efficient heuristic for the multi-vehicle one-to-one pickup and delivery problem with split loads

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    In this study, we consider the Multi-vehicle One-to-one Pickup and Delivery Problem with Split Loads (MPDPSL). This problem is a generalization of the one-to-one Pickup and Delivery Problem (PDP) where each load can be served by multiple vehicles as well as multiple stops by the same vehicle. In practice, split deliveries is a viable option in many settings where the load can be physically split, such as courier services of third party logistics operators. We propose an efficient heuristic that combines the strengths of Tabu Search and Simulated Annealing for the solution of MPDPSL. Results from experiments on two problems sets in the literature indicate that the heuristic is capable of producing good quality solutions in reasonable time. The experiments also demonstrate that up to 33\% savings can be obtained by allowing split loads; however, the magnitude of savings is dependent largely on the spatial distribution of the pickup and delivery points

    A molecular epidemiological study of black queen cell virus in honeybees (Apis mellifera) of Turkey: the first genetic characterization and phylogenetic analysis of field viruses

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    Black queen cell virus (BQCV) is one of the most common honeybee pathogens causing queen brood deaths. The 63 apiaries were sampled between 2007 and 2013 from four different ecogeographic regions in Turkey to estimate BQCV molecular structural characteristics. The BQCV positivity was 47.6%. The 25 local Black queen cell viruses (TrBQCVs) were molecularly characterized and investigated for their genetic relationship with previous records. The identity of the helicase gene among the TrBQCVs was 92-98%, whereas the similarity ranged from 37 to 85% in comparison with the intercontinental records. The identity of the partial capsid gene among the TrBQCVs was 91-100%, and the similarity rate varied from 86 to 97, 88-96, 90-97 and 89-99% in comparison with the Asian, African, American and European counterparts, respectively. The four nonsynonymous substitutions on the partial capsid protein suggest a predicted genotype that is specific among TrBQCVs

    Corrosion inhibition of st37 steel in geothermal fluid by quercus robur and pomegranate peels extracts

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    Plant extracts have become important as an environmentally acceptable, readily available and renewable source of wide range of inhibitors. Tannins, a class of natural, non toxic and biodegradable polyphenolic compounds, extracted from plant sources are already used as corrosion inhibitors in aqueous media. This study investigates the inhibiting effect of Quercus robur and pomegranate peels extracts on st37 steel corrosion in geothermal fluid using the Tafel polarization method. It was found that the extracts act as good corrosion inhibitors for geothermal fluid. 250 ppm of Quercus robur oak extract was seen to have 90% corrosion inhibition efficiency. The values of pH, potential, conductivity, total hardness and Ca2+ hardness, dissolved solid substance (TDS) and salinity of geothermal fluid were analyzed before and after the addition of extract into it. According to these analyses, increasing pH level more than 5 indicates that corrosion con structive aggressive ions (H+) decrease. Furthermore the decrease of conductivity values as a result of the decrease of inhibitor concentration shows that corrosion slows down. Ryznar and Langelier Indexes are cal culated for AF11 well, reinjection and collected pools. The values of indexes show that geothermal fluid is corrosive and scale properties

    Neonatal Episodic Hypoglycemia: A Finding of Valproic Acid Withdrawal

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    The treatment of epilepsy during pregnancy is a worldwide problem. Drugs need to be used to control seizures in the mothers. In utero, exposure to valproic acid (VPA) and phenytoin (PH) may cause congenital malformations and also withdrawal symptoms such as irritability, jitteriness and symptoms of hypoglycemia. We present here a newborn with episodic hypoglycemia due to in utero exposure to VPA and PH. The mother was diagnosed as having complex partial epilepsy and was treated with PH (200 mg/day) and VPA (600 mg/day). The offspring developed jitteriness on the second day of life. The infant was hypoglycemic (32 mg/dl). These findings were accepted as withdrawal symptoms, since serum levels of VPA and PH were 37.8 μg/ml (50−100 μg/ml) and 6.37 μg/dl (10−20 μg/ml), respectively. Measurement of blood glucose is important and should be carefully monitored in infants exposed to antiepileptics in utero

    Can gestational exercise have a positive effect on cognitive functions resulting from brain injury? A rat study

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    Aim: The effects of gestational exercise on potential pathological conditions is not known yet.  Therefore, in the present study, it was aimed to evaluate the effects of forced running exercise on LPS-induced brain damage in pregnant rats. Method: Pregnant females in the experimental group were forced to exercise 30 min daily for five days a week. Lipopolysaccharide (LPS) induced brain injury model was created by administering 500 µg/kg body weight of LPS on gestational days 18 and 19.   To evaluate injury histopathologically, brain tissues were fixed at the postnatal day seven through transcardial perfusion (n=4 pups/group). When the remaining pups reached 30-day of age, Morris water maze test (MWM) was performed to assess memory and learning, open filed (OP) and elevated plus maze (EPM) for testing anxiety, and Porsolt test (PT) for evaluating depression. The groups were defined as brain injury group (BI, n=13) and exercise+brain injury group (E+BI, n=7).  Results: The results obtained from MWM test indicated that animals found the platform in a shorter duration and distance at the day five compared to the day three. However, there was no significant difference between the groups. No significant difference was found in OP test regarding the distance traveled, time spent at the margins, movement at the center and the time spent as immobile. However, in the EPM test, the offspring at the BI group displayed higher mobility and increased number of entry to the open arms compared to the E+BI groups (p=0.01).  There was no significant difference regarding mobility duration and total distance traveled in the PT test. Conclusion: In the present study, we tested the impact of gestational exercise using the brain injury model. The results of the EPM test suggests that the gestational exercise can suppress the stress factors in the pregnant females with brain injury leading to the prevention of hyperactivity-induced negative learning behavior

    Effects of gestational exercise on hyperoxia-induced brain damage in the newborn

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    Aim: Preterm infants encounter hyperoxia relatively early on as they leave the intrauterine environment earlier than expected, while also being exposed to a higher level of hyperoxic stress due to insufficiencies in their antioxidant defense mechanisms. With that in mind, we investigate whether running exercises performed during pregnancy can contribute to the development of tolerance to neonatal hyperoxic brain damage. Method: While two female rats maintained a sedentary pregnancy, one female rat performed the mandatory running exercise for 30 minutes for five days a week throughout the pregnancy. Following delivery, the sedentary rats and the exercised rat were kept together with their offspring for five days at oxygen concentrations above 80 percent in order to induce brain damage. The offspring were sacrificed on postnatal Day 7 and brain/body ratio measurements were obtained. Results: The brain/body ratios in the control, hyperoxia and exercise-hyperoxia groups were found to be median (IQR) 0.074(0.68-0.77), 0.065(0.06-0.067) and 0.064(0.060-0.068), respectively. The brain/body ratios of the offspring of the mothers in the hyperoxia group were found to be significantly lower than the control group (p=0.002), irrespective of exercise (p=0.007). No statistically significant difference was noted between the offspring of the sedentary and the exercised mothers in the hyperoxia group (p=0.94). Conclusion: Hyperoxia was found to result in lower brain mass relative to total body mass. This finding, which indicates the presence of microcephaly, reflects the negative effects of hyperoxia on brain development. Contrary to expectations, exercises performed during pregnancy had no significant effect on the brain/body weight ratio of the offspring

    The neuro-inflammation and excitotoxicity in perinatal brain injury: The emerging role of brain mast cells

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    Perinatal brain injury is a serious neurodevelopmental problem that can be occurred in preterm and term newborn infants. It is well established that neuro-inflammation is implicated in the pathophysiology of perinatal brain injury. The excitotoxicity is considered as a common molecular mechanism of perinatal brain injury. These insults are capable of leading to neuro-inflammation, but however neuro-inflammation is also able to induce the excitotoxicity in the developing brain. Thus, neuro-inflammation is both a cause and a consequence of excitotoxicity resulting in the brain damages during perinatal period. Excessive glutamate accumulation in the synaptic cleft in the brain is a prominent mechanism in the excitotoxicity while vasoactive and pro-inflammatory mediators such as histamine, prostaglandins, interleukin 1 (IL-1) β and tumor necrosis factor (TNF)-α released from brain-resident immune cells play a major role in neuro-inflammation that lead to the brain damages. Although the role of brain-resident microglial cells has been well documented in these neuro-inflammation processes, evidence for the role of brain mast cells (BMCs) has recently begun to emerge. Growing evidence indicates that brain mast cells are first responders of inflammatory insults in the developing brain and their activation is involved in induced brain injury. We have recently demonstrated that ibotenate-induced excitotoxicity leads to the activation of brain mast cells in a model of ibotenate-induced brain injury in newborn rats. Thus, in this review we point out the current knowledge on the bidirectional role of brain mast cells in neuro-inflammation and excitotoxicity underlying perinatal brain injury

    Iodine Overload and Severe Hypothyroidism in Two Neonates

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    Iodine overload frequently leads to transient hyperthyrotropinemia or hypothyroidism, and rarely to hyperthyroidism in neonates. Iodine exposure can be prenatal, perinatal or postnatal. Herein we report two newborn infants who developed severe hypothyroidism due to iodine overload. The overloading was caused by excessive use of an iodinated antiseptic for umbilical care in the first case, and as a result of maternal exposure and through breast milk with a high iodine level in the second case. Presenting the two cases, we wanted to draw attention to these preventable causes of hypothyroidism in infants
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