Cannabinoids: A Novel Treatment Strategy for Retinal Neurodegenerative Disorders

Synthetic and naturally occurring cannabinoids are known to decrease intraocular pressure (IOP). Glaucomatous damage to the retina and optic nerve progresses even after therapy to maintain normal intraocular pressure (IOP). Topical application of cannabinoids decreases IOP while not affecting blood pressure or heart rate. Based upon their effects on other tissues, we hypothesize that these analogs reduce IOP and may also confer direct neuroprotective effects on the retina, possibly via CB1 and/or CB2 receptors. The purpose of this study is to determine if the newly synthesized CB agonists, lipid soluble O-1812 (CB 1), and water soluble O-2545 (CB 1 The IOP effects were tested in a rat glaucoma model, which was created Sprague-Dawley rats by ligating 3 of 4 episcleral veins. IOP increased by at least 5 mm Hg in the operated eye, measured via Goldmann tonometry under sedation. Retinal damage was induced by injecting NMDA (2 µl of 10 mM) intravitreally in Sprague-Dawley rats. In other groups O-1812 (2 mM) and O-2545 (2mM) were co-injected with NMDA. Electroretinograms (ERG) were recorded at baseline, 1 wk and 2 wk after injection. Contralateral normal eyes served as controls. After 2 wk, retinas were flat mounted and stained with H&E. While both O-compounds showed significant IOP decrease, lipid soluble O-1812 had the most rapid onset. O-1812 was also effectively restricted a-wave amplitude loss; O-2545 was less effective. Retinal whole mounts of NMDA alone showed areas devoid of cells, while those treated with O-1812 and O-2545 were intact with an even distribution of retinal ganglionic cells. Considering both IOP and neuroprotective effects, lipid soluble O-1812 was deemed to be most effective

God, sin, and salvation in Indian philosophy

https://place.asburyseminary.edu/ecommonsatsdissertations/2006/thumbnail.jp

TRAINING PRE-SERVICE GENERAL EDUCATORS TO COLLECT ACCURATE ANTECEDENT-BEHAVIOR-CONSEQUENCE DATA

Functional behavior assessment is a process that should involve all individuals that work closely with a student who is engaging in problematic behavior that impacts their own or others’ learning. General educators are typically involved in this process through indirect or descriptive assessments, such as collecting antecedent-behavior-consequence data (ABC). However, there are many factors that can impact a general educator’s ability to collect accurate ABC data. Inaccurate data can misinform appropriate responses and interventions for challenging behaviors made by a student’s decision-making team, such as an Individual Education Program (IEP) team. Therefore, it is critical that researchers empirically evaluate training interventions that can be used to provide instruction on this skill. The purpose of this study was to evaluate the use of behavioral skills training (BST), with video vignettes used for modeling and rehearsal, to train pre-service general educators how to collect accurate antecedent-behavior-consequence (ABC) data using a structured recording format via a single-case research design. This study also sought to program and assess generalization of the skill to a narrative format. This format is typically used in schools but often yields less reliable and more subjective data. Lastly, four administrations of a pre- and posttest were used to assess incidental learning of non-target information provided via instructive feedback. Results indicate BST was effective for training pre-service general educators to collect ABC data using a structured recording format. Participants were able to generalize the skill to a narrative recording format. Performance on non-target information posttests were variable across participants. These findings extend the literature on BST and highlight a way for researchers to facilitate generalization within the context of an experimental design

Manufacture and Evaluation of Cast Aluminum Foam Heat Exchangers

Metal foams have many attractive properties such as light weight, low relative density, energy absorption capability etc. One of the main advantages of metal foam is that the foam inherits several properties of the parent metal, at the same time, at a fraction of the weight. Metal foams are basically of two types; closed pore and open pore. In the open pore configuration the highly porous structure with large surface to volume ratio is attractive in thermal applications such as heat exchangers, small scale refrigeration, diesel exhaust cooling and heat sink for electronics. Large surface area to volume ratio of the heat transfer area is an important parameter in design of heat exchangers. Application of open cell metal foam as a heat exchanger involves production of the metal foam, cutting/drilling the metal foam to required dimensions and attaching it to a substrate or duct. Foams are cut by various methods such as by using circular saw, band saw, abrasive sawing wire or electrical discharge machining. Cutting or drilling operations plastically deform the struts and affect the surface roughness of the struts and hence, the contact area between the foam and the substrate. The foam and the substrate are then joined to get the final product. Various techniques are adopted to join the foam and substrate that includes, press fit, welding, soldering, brazing and use of epoxy adhesives or thermal glue. These methods either deform the foam plastically or involve a bonding material which involves an additional step in manufacturing and is generally necessary to reduce the thermal resistance at the interface. Every secondary step involved in machining the foam and joining it to substrate/duct add to the energy, time and cost of the component. Significant amount of materials wastage occurs during the production and machining steps of the metal foam. Bonding material used for attaching foam to the substrate makes the recycling of the heat exchangers difficult. In the present research work the above issues were rectified by introducing a novel method of fabricating the heat exchanger in a single step. This can be done by producing open cell foam, bonded to the substrate in a single step to get the ready to use heat exchanger. The uniqueness of the method/ process is that it provides an advantage of manufacturing heat exchangers consisting of open cell aluminium foam both inside and outside the aluminium duct/substrate. Here open cell metal foam is metallurgic ally bonded to the aluminium duct without producing any distortion in the aluminium duct. The present method avoids the secondary cutting and joining operations, hence reducing material and energy wastage. This heat exchanger does not need a bonding material at the foam duct interface which makes the product completely recyclable without even having to separate the aluminium foam and, many-at-times, the copper substrate. Further, in the present process no hazardous material is involved in the fabrication process of the heat exchanger and all the materials used for the foam production can be recycled. Another unique advantage of this process is that the foam can also be cast inside and outside the tube in a single step. This helps increase the heat transfer area per unit volume inside the tube increasing the effectiveness significantly. First, an attempt was made to cast aluminium foam over a Cu substrate. Spheres made of Plaster of Paris (PoP) were used as space holders to create pores in the foam. First, a dough of PoP was prepared by mixing sufficient amount of water with the powder of PoP. Small pieces of PoP were taken from the dough and were rolled by hands to prepare spherical balls. Next, a casting setup was made where a die made of stainless steel was placed in a crucible whose bottom was filled with sand. A tube/duct made of copper was placed at the centre of the die and PoP balls were dropped around the duct. This setup was then placed in a furnace and was preheated to remove all the moisture from the PoP. Molten aluminium at around 700 °C was poured into the preheated die. After solidification, the die was opened and cast was allowed to cool in ambient air. PoP balls were removed by using a sharp needle and by dipping the casting in acetic acid. After removal of PoP from the cast, interconnected holes/cavities formed in the place of space holders/PoP balls, forming pores in the foam. There are some limitations of this method such as removal of PoP was tedious and needed chemicals that need to be discarded, PoP cannot be recycled and creates waste, small amount of moisture present in PoP balls can cause an explosion. The bonding between aluminium foam and Cu substrate obtained was not good, giving rise to thermal contact resistance. Due to the above limitations further implementation of this process using PoP was not explored further. There was a need of space holder material which can withstand the temperature of molten Al and also can be removed easily from the cast without any use of chemicals. Obtaining metallic bonding between foam and Cu substrate was difficult due to the corrosion layer formation at the interface of Al and Cu substrate due to preheating. If preheating was not carried out full penetration of the molten aluminium did not take place in the space available in between the spheres. Therefore, it was decided to cast Al foam over Al substrate. The main challenge and difficulty was to cast open cell Al foam inside and outside the tube/duct made of the same material (Al) without distorting the tube/duct as well as achieving consistent metallic bonding between the two. This has been successfully done by gravity casting method a single step manufactured and ready to use open cell Al foam heat exchanger were fabricated. A casting setup was prepared, which consisted of a commercially pure aluminium tube placed in the middle of a stainless steel split die. The gap between the tube and die was filled with the salt spheres. An uncommon and new approach was adopted to produce NaCl salt spheres. NaCl salt balls (spherical and ovoid) of different diameters were processed by casting route. The casting step of NaCl is necessary as the moisture present in NaCl can be completely removed during the melting of NaCl. NaCl was chosen as it had a melting point higher than aluminium. The casting setup was placed in a furnace and was preheated to various temperatures up to 550 °C. Commercially pure aluminium was melted separately in a crucible and was poured into the steel die at 700oC. The liquid metal flows through the die and fills the cavities between the salt balls. The die was opened immediately after solidification of molten Al and cast was allowed to cool in ambient air. The salt (NaCl), which was still solid, was dissolved in water to get the foam structure. With proper control of the preheat temperature and temperature of liquid aluminium no distortion of the aluminium duct was observed throughout the length of the heat exchanger. Consistent and complete fusion/ metallic bonding was observed at the interface of Al foam and Al substrate/duct. Several heat exchangers with different porosity and pore geometry with the aluminium foam cast outside the tube and both inside and outside of the tube were fabricated. The beauty of the designed method is that it is simple and cost effective and eliminates the major issue of thermal contact resistance since the foam and the duct are made of the same material and are bonded in the liquid state leaving no interface between the foam and the duct. Further, foam can also be cast inside the duct in the same step while casting the foam outside the tube, giving an integral heat exchanger which has higher heat transfer surface area to volume ratio inside and outside the duct. This is expected to further improve the efficiency and effectiveness of the heat exchanger An added advantage of this method is that the heat exchanger can be recycled easily in a single step re-melting route. Further, the heat exchanger does not use any hazardous material during manufacture that needs attention during recycling. After the production and fabrication of the heat exchangers, the thermal performance or effectiveness of the heat exchangers was assessed, to evaluate its usefulness and suitability for heat transfer application. An experimental test setup was fabricated in the laboratory to perform the heat transfer tests. The experimental test setup consists of the following major components;1) A test chamber whose function was to insulate the heat exchangers from the surroundings and to avoid any heat loss to the surroundings, 2) An air blower used to supply cold fluid (air) to the test chamber, 3) A constant temperature bath was used to supply the hot fluid, which was water in this case, in the duct of the heat exchanger, 4) A rotameter was used to measure the volumetric flow rate of the cold fluid and 5) A pressure gauge having the pressure measurement range between 1 mbar to 160 mbar to measure the pressure drop across the test chamber. K-type chromel – alumel thermocouples having temperature measurement range between -270 °C to 1,260 °C were used to measure the temperature of hot and cold fluids during the experiments. By aid of the data logger system and computer, temperature readings were recorded during the tests and were used further for the heat transfer calculations. For testing the aluminium foam heat exchangers was placed in the insulated test chamber. Hot water was supplied inside the duct of heat exchanger whereas air at room temperature was supplied around the foams at varying flow rates during the tests. During the tests, temperature readings were taken at steady state condition. NTU-Effectiveness method was used to evaluate the thermal performance of heat exchangers. Overall results obtained by this experimental study are as follows • As the inlet temperature difference between hot and the cold fluids increases the heat transfer rate and the effectiveness of the heat exchangers also increases. • At a constant flow rate of hot fluid, heat exchangers exhibits significantly better thermal performance at lower flow rate of cold fluid compared to higher flow rate. As the flow rate of cold fluid increases, the velocity of the fluid increases and consequently, reduces the optimum interaction time between hot and the cold fluids required for the efficient heat transfer. • At a constant and low flow rate of cold fluid the effectiveness of the heat exchanger increases as the porosity of the foam increases. But when the flow rate of cold fluid was increased further after a certain limit, the effectiveness value of the heat exchanger decreases. • Heat exchanger consisting of foam of higher porosity exhibits higher effective. • Heat exchanger having foam inside and outside of the duct/tube exhibits significantly higher effectiveness compared to Al duct, Cu duct and other heat exchanger tested. • At a higher flow rate of the cold fluid, the heat exchangers consisting of foams of higher porosity, experience more drop in effectiveness compared to the heat exchanger having foams of low porosity. • Pressure drop across the length of the foam/fin increases as the volumetric flow rate of the cold fluid (m3/s) increases. • Surface area per unit volume and effectiveness values for bare Al tube is very low compared to Al foam heat exchangers resulting in the bare Al tube exhibiting much lower effectiveness compared to heat exchanger made of Al foam. • For a certain flow rate of fluids, the effectiveness of the heat exchanger increases up to a certain thickness of the Al foam. • Regardless of the thickness of the foam, the effectiveness of the heat exchangers is low at higher flow rate of cold fluid compared to lower flow rate. • These foam based heat exchanger had a much higher effectiveness when compared to that of other heat exchangers, data of which were got from literature. The present experimental study concludes that fuse bonding open cell aluminium foam over an Al duct or Al substrate can improve the thermal performance of the heat exchanger significantly. The thesis includes five chapters. Chapter 1 gives a detailed introduction about the metal foam, heat exchangers, thermal contact resistance and its effect on the heat transfer rate has been explained. This chapter also includes the overall aim and motivation for the research work. Chapter 2 covers the literature available on production methods of metal foam and its limitations has been listed out. And conventional methods of manufacturing open cell metal foam heat exchangers and its disadvantages have been explained in detailed. Chapter 3 covers in detail the novel method of production and fabrication of open cell metal foam heat exchangers. Chapter 4 includes an experimental study, where thermal performance of heat exchangers has been assessed through heat transfer experiments. Chapter 5 is the conclusions and future works

New Pressing Technique for Preparation of small-Calibre Shaped Charge

Explosive filling in small-calibre shaped charges is carried out by pressing techniques. At present, pressing is carried out by single action method which suffers a drawback of density gradient in the charge from the face of the tool. A new method-double action pressing-has been established which eliminates this problem. Filling quality of charge of 30 mm calibre prepared by this method especially with respect to the density gradient is presented and discussed

The Utility of Bedside Ultrasound in the Detection of a Ruptured Globe in a Porcine Model

Background: Recent case reports have shown that ultrasonography can be used to diagnose ocular pathology in an emergency setting. Ultrasound may be especially useful when periorbital edema and pain interfere with the examination of the post-traumatic eye.Objective: This study evaluated the ability of emergency physicians to detect a ruptured globe in an ex-vivo porcine model.Methods: Following a brief training lecture, 15 emergency medicine residents and 4 emergency medicine attending physicians used ultrasonography to evaluate 18 porcine eyes, randomized as normal, ruptured, or completely devoid of vitreous humor. The consequences of ultrasound applanation with this method were evaluated by measuring intraocular pressure changes with and without a 1mm clear plastic shield.Results: Our study participants were able to identify abnormal eyes with a sensitivity of 79% (95% CI 73% to 84%) and a specificity of 51% (95% CI 41% to 61%). Intraocular pressure increased 5% with ultrasound applanation, though with a 1mm thick plastic shield there was no measurable change.Conclusions: Ultrasound imaging may be a future modality to be used by trained emergency physicians to expedite the identification of a rupture globe, but it is unlikely to replace more definitive imaging techniques. The use of a clear plastic barrier in this porcine model prevents an increase in intra-ocular pressure without affecting image quality, and should be used in any future studies on this method.[West J Emerg Med. 2009;10(4):263-266.

Service user involvement for mental health system strengthening in India:A qualitative study

Background: There is a wide recognition that involvement of service users and their caregivers in health system policy and planning processes can strengthen health systems; however, most evidence and experience has come from high-income countries. This study aimed to explore baseline experiences, barriers and facilitators to service user-caregiver involvement in the emerging mental health system in India, and stakeholders' perspectives on how greater involvement could be achieved. Methods: A qualitative study was conducted in Sehore district of Madhya Pradesh, India. In-depth interviews (n = 27) and a focus group discussion were conducted among service users, caregivers and their representatives at district, state and national levels and policy makers, service providers and mental health researchers. The topic guide explored the baseline situation in India, barriers and facilitators to service user and caregiver involvement in the following aspects of mental health systems: policy-making and planning, service development, monitoring and quality control, as well as research. Framework analysis was employed. Results: Respondents spoke of the limited involvement of service users and caregivers in the current Indian mental health system. The major reported barriers to this involvement were (1) unmet treatment and economic needs arising from low access to mental health services coupled with the high burden of illness, (2) pervasive stigmatising attitudes operating at the level of service user, caregiver, community, healthcare provider and healthcare administrators, and (3) entrenched power differentials between service providers and service users. Respondents prioritised greater involvement of service users in the planning of their own individual-level mental health care before considering involvement at the mental health system level. A stepwise progression was endorsed, starting from needs assessment, through empowerment and organization of service users and caregivers, leading finally to meaningful involvement. Conclusions: Societal and system level barriers need to be addressed in order to facilitate the involvement of service users and caregivers to strengthen the Indian mental health system. Shifting from a largely 'provider-centric' to a more 'user-centric' model of mental health care may be a fundamental first step to sustainable user involvement at the system level.</p