1,597 research outputs found

    Navigation and attitude reference for autonomous satellite launch and orbital operations

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    The navigation and attitude reference performance of a strapdown system are investigated for applications to autonomous satellite launch and orbital operations. It is assumed that satellite payloads are integrated into existing missile systems and that the boost, orbit insertion, and in-orbit operation of the satellite are performed autonomously without relying on external support facilities. Autonomous and long term accurate navigation and attitude reference are provided by a strapdown inertial navigation system aided by a star sensor and earth landmark sensor. Sensor measurement geometry and navigation and attitude update mechanizations are discussed. Performance analysis data are presented for following functional elements: (1) prelaunch alignment; (2) boost navigation and attitude reference; (3) post boost stellar attitude and navigation updates; (4) orbital navigation update using sensor landmark measurements; and (5) in-orbit stellar attitude update and gyro calibration. The system performances are shown to satisfy the requirements of a large class of satellite payload applications

    Corak Fikih Literalistik-Tekstualistik

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    This paper describes the pattern and characteristics of literal fiqh, jurisprudence that legal opinion can be deduced from the Koran and the hadith texts. Textual understanding is characterized by an emphasis on language analysis. Literal jurisprudence manifests form is evident in the school of Zhahiri with Ibn Hazm as the central scholar. Analytical description of jurisprudence in this paper is compared with substantialrationale base jurisprudence; therefore, the second mode of jurisprudence is seen between the two specifications. One who studies jurisprudence is encouraged to browse and find out where the basic norms or philosophical values, where the norms and the concrete rules that are classified as instruments

    Strapdown calibration and alignment study. Volume 1 - Development document Final report

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    Calibration and alignment techniques for inertial sensing uni

    Drug-Induced Plasticity Contributing to Heightened Relapse Susceptibility: Neurochemical Changes and Augmented Reinstatement in High-Intake Rats

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    A key in understanding the neurobiology of addiction and developing effective pharmacotherapies is revealing drug-induced plasticity that results in heightened relapse susceptibility. Previous studies have demonstrated that increased extracellular glutamate, but not dopamine, in the nucleus accumbens core (NAcc) is necessary for cocaine-induced reinstatement. In this report, we examined whether drug-induced adaptations that are necessary to generate cocaine-induced reinstatement also determine relapse vulnerability. To do this, rats were assigned to self-administer cocaine under conditions resulting in low (2 h/d; 0.5 mg/kg/infusion, i.v.) or high (6 h/d; 1.0 mg/kg/infusion, i.v.) levels of drug intake since these manipulations produce groups of rats exhibiting differences in the magnitude of cocaine-induced reinstatement. Approximately 19 d after the last session, cocaine-induced drug seeking and extracellular levels of glutamate and dopamine in the NAcc were measured. Contrary to our hypothesis, high-intake rats exhibited a more robust cocaine-induced increase in extracellular levels of dopamine but not glutamate. Further, increased reinstatement in high-intake rats was no longer observed when the D1 receptor antagonist SCH-23390 was infused into the NAcc. The sensitized dopamine response to cocaine in high-intake rats may involve blunted cystine–glutamate exchange by system xc−. Reduced 14C-cystine uptake through system xc− was evident in NAcc tissue slices obtained from high-intake rats, and the augmented dopamine response in these rats was no longer observed when subjects received the cysteine prodrug N-acetyl cysteine. These data reveal a role for drug-induced NAcc dopamine in heightened relapse vulnerability observed in rats with a history of high levels of drug intake

    Kritik Atas Fikih Lintas Agama: Studi Atas Pemikiran Kaum Revivalis

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    This paper explains the revivalist Islamic criticism of the views of the Paramadina Writers Team which permits interfaith marriages and permissibility of inheritance of different religions. This research is a library research with the main data source is the book Fiqh Lintas Agama: Membangun Masyarakat Inklusif-Pluralis. The results showed that Islamic revivalists argued that the history of Mu'azd and Muawiyah which was used as a reference by the Paramadina Writers Team did not agree on its validity compared to the history which forbids a Muslim from inheriting infidels. Whereas giving precedence to an agreed proposition of validity is more important to be held against than an argument whose validity is not agreed upon. Choosing a majority opinion over the opinion of a minority is more prioritized. The case where the majority of scholars forbid interfaith marriages is haram because of the textual statements of the verse, except marriages with the ahl al-kitab. That skill is also an emergency. Even the adverse effects of interfaith marriages must take precedence over benefits

    Blunted Cystine–Glutamate Antiporter Function in the Nucleus Accumbens Promotes Cocaine-induced Drug Seeking

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    Repeated cocaine alters glutamate neurotransmission, in part, by reducing cystine–glutamate exchange via system xc−, which maintains glutamate levels and receptor stimulation in the extrasynaptic compartment. In the present study, we undertook two approaches to determine the significance of plasticity involving system xc−. First, we examined whether the cysteine prodrug N-acetylcysteine attenuates cocaine-primed reinstatement by targeting system xc−. Rats were trained to self-administer cocaine (1 mg/kg/200 μl, i.v.) under extended access conditions (6 h/day). After extinction training, cocaine (10 mg/kg, i.p.) primed reinstatement was assessed in rats pretreated with N-acetylcysteine (0–60 mg/kg, i.p.) in the presence or absence of the system xc− inhibitor (S)-4-carboxyphenylglycine (CPG; 0.5 μM; infused into the nucleus accumbens). N-acetylcysteine attenuated cocaine-primed reinstatement, and this effect was reversed by co-administration of CPG. Secondly, we examined whether reduced system xc− activity is necessary for cocaine-primed reinstatement. To do this, we administered N-acetylcysteine (0 or 90 mg/kg, i.p.) prior to 12 daily self-administration sessions (1 mg/kg/200 μl, i.v.; 6 h/day) since this procedure has previously been shown to prevent reduced activity of system xc−. On the reinstatement test day, we then acutely impaired system xc− in some of the rats by infusing CPG (0.5 μM) into the nucleus accumbens. Rats that had received N-acetylcysteine prior to daily self-administration sessions exhibited diminished cocaine-primed reinstatement; this effect was reversed by infusing the cystine–glutamate exchange inhibitor CPG into the nucleus accumbens. Collectively these data establish system xc− in the nucleus accumbens as a key mechanism contributing to cocaine-primed reinstatement

    Studi Metodologis Fikih Zakat Profesi dalam Perspektif Yusuf Al-Qardhawi

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    The purpose of this study was to determine the method, foundation and reasoning of Yusuf al-Qardhawi's law on professional zakat. This research is a library research with data collection methods in the form of quoting, adapting and analyzing using content analysis. The results showed that according to Yusuf al-Qardhawi, ijtihad is a serious effort by exerting all abilities by those who have the authority in order to find answers to religious law through istinbât both done hourly (collective) or fardi (individual) by involving other experts . The results of the ijtihad are based on the maqâsid al-syarî‘ah using the qiyas method. On the basis of this principle Yusuf al-Qardhawi stipulates that in determining the obligatory zakat from the profession does not wait a year. The determination of the law does not stand alone, but is supported by the Qur'anic texts, hadith, and analogies. The aspect of justice in determining the obligation of professional zakat for every Muslim is because zakat is essentially worship related to property. A person who has fulfilled his requirements is required to fulfill it, not solely on the basis of his generosity, but if necessary even under pressure from the authorities

    Hydro-institutional mapping in the Steelpoort River Basin, South Africa

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    River basins / Institutions / Organizations / Private sector / Public sector / Local government / Mapping / Water resource management / Water policy / Legislation / Rural women / Constraints / Groundwater / Surface water / Water quality / Water use / Water users / Dams / Reservoirs / Large-scale systems / Irrigation management / Industrialization / Case studies / Operations / Maintenance / Canals / Conflict / Farmer-agency interactions / Policy / Water supply / Rural development

    Repeated \u3cem\u3eN\u3c/em\u3e-Acetylcysteine Administration Alters Plasticity-Dependent Effects of Cocaine

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    Cocaine produces a persistent reduction in cystine–glutamate exchange via system xc− in the nucleus accumbens that may contribute to pathological glutamate signaling linked to addiction. System xc− influences glutamate neurotransmission by maintaining basal, extracellular glutamate in the nucleus accumbens, which, in turn, shapes synaptic activity by stimulating group II metabotropic glutamate autoreceptors. In the present study, we tested the hypothesis that a long-term reduction in system xc− activity is part of the plasticity produced by repeated cocaine that results in the establishment of compulsive drug seeking. To test this, the cysteine prodrug N-acetylcysteine was administered before daily cocaine to determine the impact of increased cystine–glutamate exchange on the development of plasticity-dependent cocaine seeking. Although N-acetylcysteine administered before cocaine did not alter the acute effects of cocaine on self-administration or locomotor activity, it prevented behaviors produced by repeated cocaine including escalation of drug intake, behavioral sensitization, and cocaine-primed reinstatement. Because sensitization or reinstatement was not evident even 2–3 weeks after the last injection of N-acetylcysteine, we examined whether N-acetylcysteine administered before daily cocaine also prevented the persistent reduction in system xc− activity produced by repeated cocaine. Interestingly, N-acetylcysteine pretreatment prevented cocaine-induced changes in [35S]cystine transport via system xc−, basal glutamate, and cocaine-evoked glutamate in the nucleus accumbens when assessed at least 3 weeks after the last N-acetylcysteine pretreatment. These findings indicate that N-acetylcysteine selectively alters plasticity-dependent behaviors and that normal system xc− activity prevents pathological changes in extracellular glutamate that may be necessary for compulsive drug seeking
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