LC

The effects of increased salinity were evaluated on the ovum fertilization of the sea urchin species, Strongylocentrotus franciscanus Agassiz, 1863 and Lytechinus anamesus Clark, 1912, which were collected by means free–diving in the bay Todos Santos, Ensenada, B. C., Mexico. The ovum fertilization of each species of sea urchin was estimated using a range of salinity from 33.4 to 53.4‰, being considered for each case its LC50. The results indicated that the capacity of fertilization of gametes decrease as the salinity increases, reaching the LC50 at 43.4‰ for Strongylocentrotus franciscanus and 48.4‰ for Lytechinus anamesus, confirming previous research that recommended not exceed 40‰ to avoid adverse effects in life cycles of the marine fauna.

This policy brief is based on an extensive body of research across Europe and elsewhere conducted by leading researchers in the field across more than 30 countries. We have studied the use of digital technologies by children under 8 years old in a variety of settings using an extensive range of research methods.

Frequency oscillator is one of the basic devices that can be used in most electrical, electronics and communications circuits and systems. There are many types of oscillators depending on frequency range used in an application such as audio, radio and microwave. The needed was appeared to use high and very high frequencies to make the rapid development of advanced technology Colpitts oscillator is one of the most common types of oscillator, it can be used for radio frequency (RF), that its output signal is often utilized at the basic of a wireless communication system in most application. In this research, a Colpitts oscillator is comprised from a bipolar junction transistor (BJT) amplifier with LC tank. This design is carrying out with a known Barkhausen criterion for oscillation. Firstly, is carried out using theoretical calculation. The secondary is carried out using simulation (Multisim 13). All the obtained result from the above two approaches are 10 MHz and 9.745 MHz respectively. This result is seen to be very encouraging.

Cell death is a crucial process during development, homeostasis and immune regulation of multicellular organisms, and its dysregulation is associated with numerous pathologies. Cell death is often induced upon pathogen infection as part of the defense mechanism, and pathogens have evolved strategies to modulate host cell death. In this review, we will discuss the molecular mechanisms and physiological relevance of four major types of programmed cell death, namely apoptosis, necrosis, autophagic cell death and pyroptosis.

The second volume of the African Higher Education Dynamics Series brings together the research of an international network of higher education scholars with interest in higher education and student politics in Africa. Most authors are early career academics who teach and conduct research in universities across the continent, and who came together for a research project and related workshops and a symposium on student representation in African higher education governance. The book includes theoretical chapters on student organising, student activism and representation; chapters on historical and current developments in student politics in Anglophone and Francophone Africa; and in-depth case studies on student representation and activism in a cross-section of universities and countries. The book provides a unique resource for academics, university leaders and student affairs professionals as well as student leaders and policy-makers in Africa and elsewhere.

Frequency oscillator is one of the basic devices that can be used in most electrical, electronics and communications circuits and systems. There are many types of oscillators depending on frequency range used in an application such as audio, radio and microwave. The needed was appeared to use high and very high frequencies to make the rapid development of advanced technology Colpitts oscillator is one of the most common types of oscillator, it can be used for radio frequency (RF), that its output signal is often utilized at the basic of a wireless communication system in most application. In this research, a Colpitts oscillator is comprised from a bipolar junction transistor (BJT) amplifier with LC tank. This design is carrying out with a known Barkhausen criterion for oscillation. Firstly, is carried out using theoretical calculation. The secondary is carried out using simulation (Multisim 13). All the obtained result from the above two approaches are 10 MHz and 9.745 MHz respectiv...

Este estudo procurou investigar como a estrategia didatica da resolucao de situacoes-problema pode auxiliar no aprendizado de conceitos pelos alunos da 8a serie/ 9o ano do Ensino Fundamental de uma escola da rede Estadual de Calumbi, Pernambuco. Para isso, a partir das indicacoes propostas por Merieu (1998), foi elaborada, uma Situacao-problema, que teve sua tematica ligada ao efeito estufa. A obtencao dos dados foi feita usando, entre outros instrumentos, questionario impresso e entrevista semiestruturada (gravada em audio) com o professor de ciencias, e um questionario aplicado a dez alunos, apos a intervencao em sala de aula. A atividade realizada permitiu ao docente uma reflexao acerca do uso de situacoes-problema como estrategia didatica, alem de alguns aportes teoricos que fundamentam a abordagem de uso destas. As respostas dos alunos mostraram que houve de forma significativa a construcao do conhecimento em algum grau, como mostram os dados obtidos depois de analisados adequa...

Frequency oscillator is one of the basic devices that can be used in most electrical, electronics and communications circuits and systems. There are many types of oscillators depending on frequency range used in an application such as audio, radio and microwave. The needed was appeared to use high and very high frequencies to make the rapid development of advanced technology Colpitts oscillator is one of the most common types of oscillator, it can be used for radio frequency (RF), that its output signal is often utilized at the basic of a wireless communication system in most application. In this research, a Colpitts oscillator is comprised from a bipolar junction transistor (BJT) amplifier with LC tank. This design is carrying out with a known Barkhausen criterion for oscillation. Firstly, is carried out using theoretical calculation. The secondary is carried out using simulation (Multisim 13). All the obtained result from the above two approaches are 10 MHz and 9.745 MHz respectiv...

The acute 96 h LC50 of (2,4-dichlorophenoxy)acetic acid (2,4-D), a widely used agricultural herbicide, was determined on crayfish (Astacus leptodactylus Esch. 1823). Crayfish of 23.5 ± 1.49 g mean weight and 9.6 ± 0.21 cm mean length were selected for the bioassay experiments. The experiments were repeated three times, in 10 L tap water. The data obtained were statistically evaluated by the use of the E.P.A computer program based on Finney’s probit analysis method and the 96 h LC50 value for crayfish was calculated to be 32.6 mg/L in a static bioassay test system. 95% lower and upper confidence limits for the LC50 were 15.10–327.16. In conclusion, 2,4-D is highly toxic to crayfish, a non-target organism in the ecosystem. Water temperature was 23 ± 1 °C. Behavioral changes of crayfish were recorded for all herbicide concentrations.

Time Response enhancement utilizing photovoltaic based cascaded Landsman Converter (LC) structure is one of the soft strategies in the recent scenario. The prime function of a DC-DC Landsman converter is to optimize the output power of the photovoltaic array and reduce the output voltage ripples. This paper reveals the demonstration and simulation of the Cascaded Landsman Converter Inverter System (CLCIS) with a PV source. MATLAB Simulink-model for CLCIS has been created utilizing the components of Simulink and closed-loop examinations are performed with PI and Fractional-Order-PID (FOPID) Controllers. The present work deal with the comparison of transient and steady-state time responses of CLCIS with PI and FOPID controllers. The outcomes demonstrate that dynamic reaction is enhanced by utilizing FOPID controller.

In this opinion paper we introduce a school-wide concept at doctoral level aimed at professional practitioners, who wish to stay in their respective areas of work. The rationale behind this school-wide concept is that in Hungary, where its implementation is currently in progress, gaining a PhD automatically means becoming an academic. However, there is a significant demand amongst high-performing professional practitioners, who are not inclined to become academics, for further learning opportunities at the highest level. They are our target market. We also wish to respond to one of the current challenges the academy is globally facing globally, namely to maintain the highest scholarly standard while achieving high relevance for practice. The school-wide concept that can adequately engage with both of these problems is naturally a work-based one. Thus what we outline here is a professional doctorate in a school-wide context. We frame this new approach based on three principles: Poppe...

Frequency oscillator is one of the basic devices that can be used in most electrical, electronics and communications circuits and systems. There are many types of oscillators depending on frequency range used in an application such as audio, radio and microwave. The needed was appeared to use high and very high frequencies to make the rapid development of advanced technology Colpitts oscillator is one of the most common types of oscillator, it can be used for radio frequency (RF), that its output signal is often utilized at the basic of a wireless communication system in most application. In this research, a Colpitts oscillator is comprised from a bipolar junction transistor (BJT) amplifier with LC tank. This design is carrying out with a known Barkhausen criterion for oscillation. Firstly, is carried out using theoretical calculation. The secondary is carried out using simulation (Multisim 13). All the obtained result from the above two approaches are 10 MHz and 9.745 MHz respectiv...

The object tracking algorithm is used to tracking multiple objects in a video streams. This paper provides Mutual tracking algorithm which improve the estimation inaccuracy and the robustness of clutter environment when it uses Kalman Filter. using this algorithm to avoid the problem of id switch in continuing occlusions. First the algorithms apply the collision avoidance model to separate the nearby trajectories. Suppose occurring inter occlusion the aggregate model splits into several parts and use only visible parts perform tracking. The algorithm reinitializes the particles when the tracker is fully occluded. The experimental results using unmanned level crossing (LC) exhibit the feasibility of our proposal. In addition, comparison with Kalman filter trackers has also been performed.

The toxicity and the biochemical effects of olive mill wastewater and citrus processing wastewater were evaluated using acute toxicity bioassays (Gammarus pulex and Hydropsyche peristerica) and biochemical biomarkers (acetylcholinesterase [AChE] and glutathione S-transferase [GST]). The bioassays indicated toxic properties of olive mill and citrus processing wastewaters. The 24 h LC(50) values of olive mill wastewater ranged from 2.64% to 3.36% for G. pulex and 3.62% to 3.88% for H. peristerica, while the LC(50) of citrus processing wastewater was 25.26% for G. pulex and 17.16% for H. peristerica. Based on a five-class hazard classification system applied for wastewaters discharged into the aquatic environment, olive mill wastewater and citrus processing wastewater were classified as highly toxic and toxic, respectively. Results of the biochemical biomarkers showed that both agroindustrial effluents at increasing sublethal wastewater concentrations could cause inhibition of the AChE and induction of the GST activities. These first results showed that both species as well as their AChE and GST activities have the potential to be used as indicators and biomarkers for assessing olive mill and citrus processing wastewaters quality.

Oroxylum indicum is a species of flowering plant belonging to the family Bignoniaceae and have many medicinal properties which prompted us to evaluate its possible thrombolytic and cytotoxic activities. A quick and rapid methodology was applied to find out the thrombolytic effect of the methanol extract of leaves of O. indicum. Streptokinase and water were employed as a positive and negative control, respectively. Thrombolytic effect was expressed as percentage of clot lysis. O. indicum, streptokinase and water demonstrated 23.69 ± 6.97%, 78.41 ± 0.366% and 5.19 ± 0.241% clot lysis, respectively. Cytotoxic property was evaluated by the brine shrimp lethality bioassay and the result was expressed as LC50. In this study, DMSO was used as solvent and vincristine sulphate as positive control. The extract showed cytotoxicity against brine shrimp nauplii and the calculated LC50 of O. indicum and vincristine sulphate were 251.2 ?g/ml and 5.2 ?g/ml, respectively. Due to the cytotoxic and th...