326 research outputs found
Studies on the spermatozoa of the ram with special reference to the effects of deep freezing
This thesis describes studies on the spermatozoa of the ram carried out with a view to determining the effects of deep freezing
which lead to poor fertility following artificial insemination.The electro-ejaculator was employed for semen collection over
20 months and 80 samples out of 114 collections were processed.Motility of spermatozoa was assessed by scoring mass activity
in raw semen samples and by estimation of the percentage of motile
spermatozoa in raw and processed samples.Percentages of live spermatozoa and their general morphology
were studied in eosin -nigrosin stained smears and acrosomal defects
in eosin fast green FCF stained smears. Spermatozoal morphology
was also studied with the electron microscope.Generally the various parameters of the raw semen were within
or close to the standard ranges and they varied with season, best semen being collected in the autumn.When semen was frozen by a standard technique there was a continuous reduction in the spermatozoal viability, especially
motility, associated with an increase in morphological deterioration
of the spermatozoa, especially of their acrosomes, following each stage.
At the same time variation in spermatozoal viability and morphology
existed between different samples.Various modifications of the freezing technique were tried.
On inclusion of 2 -8% glycerol or dimethyl sulphoxide (DMSO), or their
combinations at different levels in an egg yolk and lactose diluent
the results respectively showed that 4% glycerol, 3% DMSO and 2%
glycerol with 1.5% DMSO were the optima.The effects on spermatozoa of various equilibration times
(0.5 - 24.0 hours), dilution rates (1:1 - 1:10), thawing media (sodium
chloride or citrate with or without lactose in solution at 37 °C or frozen pellet at -196 °C) and thawing temperatures (0 °C - 100 °C) were
studied using both 4% glycerol or 3% DMSO as the cryoprotective in the
diluents. The results showed that equilibration of 3.0 hours with
glycerol, and of 1.5 hours with DMSO, and dilution rates of 1:4 and
thawing directly in a dry test tube at 37 °C - 100 °C, irrespective of
the cryoprotective, were the optima.In addition, various methods of dilution (dropping or direct
at 4 °C or 20 °C or their combination) and different egg yolk levels
(25 or 50%) with or without sodium citrate (3%) were used. The
results indicated that equilibration at 20 °C, irrespective of method
of dilution led to a high death rate of ram spermatozoa but provided
surviving spermatozoa some resistance against cold shock during freezing. Direct addition of the diluent irrespective of the equilibration
temperature was satisfactory, but the addition of the diluent by
dropping for 0.5 hour at 20 °C followed by 1.0 hour equilibration at
4 °C was superior.Increasing the egg yolk level from 25 to 50, with or without
sodium citrate in 4% glycerol containing diluent was harmful which
might be the result of binding up of glycerol.Prompt dilution of the raw semen after collection and the
avoidance of temperature fluctuation between stages of freezing and
when sampling f,or thawing were tried and the results showed an enhanced
resistance to cold shock and an improvement in spermatozoal motility
when thawed after 24 hours storage at -196 °C. However, longer storage
X was still deleterious, and the percentage of motile spermatozoa fell
to 40/.The post -thawing life span and morphological changes of the ram spermatozoa were evaluated following thawing at 0°C - 100°C and
incubation at 39°C for 0, 3.0 and 6.0 hours. The results showed
that the life span of the frozen -thawed ram spermatozoa was short
(around 3 hours) and their acrosomal defects increased progressively
as the incubation time increased.The fertilizing efficiency of frozen semen stored for 42 - 46
days was tried on 28 ewes, but the results showed that the low
post -thawing motility and short survival time which pertained were
not adequate to produce pregnancy
Reasons for Delaying the Constriction Projects in Iraq
This article dealt with construction projects in Iraq, and the research focused on the risks that may affect these projects. The purpose of this study is to determine the risks that construction projects are exposed to in Iraq and the methods of dealing in order to reduce these risks. Sometimes, if the construction projects are similar to each other in terms of configuration, requirements and purpose, then changing the project site is very sufficient to make these projects differ from each other and thus may be exposed to different risks. These are risks that negatively affect the implementation of these projects and may lead to delay or increase in their cost. Here a questionnaire is designed to collect data to identify risks that may occur during the construction project phases. This questionnaire was distributed electronically to several samples in the public and private sectors within state institutions in Iraq. After completion, the risks that these projects may be exposed to were identified. This was done with engineers and managers of companies and projects working in the public, private and joint sectors, and then these risks were analyzed by the Social Sciences for Packet Statistical Test program(SPSS)
An update on the potential for male contraception : emerging options
The human population continues to grow and is estimated to rise to 10.1 billion by the end of the century. Therefore, there is still an unmet need for safe and highly effective contraceptive options for both men and women. Current options available to men include withdrawal, condoms, and vasectomy. Methods in development fall into two categories: hormonal and nonhormonal. This review will provide an overview of the testosterone combinations and immunocontraception of hormonal targets. Nonhormonal immunocontraception of sperm proteins will also be examined, together with the use of agents to disrupt other sperm-associated targets and pathways. The categories focused on include epididymal proteins, testicular kinases, epigenetic reader proteins, opioids, lonidamine derivatives, retinoic acid, microRNAs associated with spermatogenesis, and plant extracts. Considering these developments, the number of options available to men is likely to increase in the near future
Corporate Social Responsibility, Shariah-Compliance, and Earnings Quality
This study examines the effect of two potential sources of ethical principles on earnings quality: corporate social responsibility (CSR) and membership in a Shariah index. We define membership in a Shariah index as the adherence to an ethical code that relates to Islam. Our sample comprises firms in ten European Union countries for the period from 2003 to 2013. The empirical results show that firms with a high degree of CSR are less likely to manage earnings. In contrast, membership in a Shariah index leads to earnings manipulation. Our results are robust after using several alternative quality metrics for earnings. Furthermore, our empirical results indicate that highly rated CSR firms that are not Shariah-compliant are less likely to engage in earnings manipulation. Further, institutional factors are also important in determining the link between CSR, Shariah-compliance, and the quality of financial reporting
The replacement of Canada Balsam by Nail Polish to Maintaining and Fixing Parasites Samples and Ear Drop Instead of Oil for Oil Lens on slides
تم استبدال كندا بلسم بمثبت صبغ الأظافر الشفاف في حفظ الطفيليات على الشرائح الزجاجية ولثلاث مجاميع متتالية وعلى مدى ثلاث سنوات من السنة 2007 وبعد ملاحظة وضوحها ومدى المحافظة على شكل العينات عند معاينتها تحت المجهر وأنها لم تتأثر ووجد إن نسبة التلف 7.2% بسبب تكون فقاعات نتيجة وجود رطوبة إذ إن العينة يجب أن تحوي على اقل ما يمكن من الرطوبة وهذه فقط لشرائح المجموعة الأولى (3 سنوات) أما المجموعتان التاليتان فلم يتواجد تالف (1 و2 سنة).وتم فحصها للسنوات اللاحقة ولغاية 2019/1/1 ولم يحدث تغير في الشرائح.three group successively for three groups on an period of three years from 2007, after seen how it was clear and stable of sample formation under the microscope and it not affected that the ruin ratio 7.2 % because of consistence of water bubbles of humidity, samples mast have the fewest humidity it can be, and it find only in the first group(three years) but the two other groups it haven’t any damaged slides (1,2 year) and it all has been examined till 1\1\2019 and find no changing in any of the slides.  
Case report: Neoadjuvant systemic therapy for melanoma
We report a case of rapidly enlarging metastatic melanoma in 45-year-old White male following primary resection of thin melanoma five years ago. Location and large size of the lesion possessed significant risk of complications from surgery, therefore provided a challenge in treatment options. Neoadjuvant targeted chemotherapy was commenced and resulted in a significant reduction in size of the lesion, which allowed subsequent safe surgical resection with no residual disease on histopathology results. This case provides a good example of successful utilization of neoadjuvant systemic therapy in advanced metastatic melanoma
Advanced IoT Technology and Protocols: Review and Future Perspectives
The Internet of Things (IoT) has emerged as a disruptive paradigm, altering how we interact with our surroundings and enabling a plethora of novel applications across multiple sectors. This literature review provides a complete overview of the Internet of Things, including applications, technology, protocols, modeling tools, and future directions. The assessment begins by looking at a wide range of IoT applications, such as smart cities, healthcare, industrial automation, smart homes, and more. It then looks into the underlying technologies that enable IoT deployments, including low-power wireless communication protocols, edge computing, and sensor networks. Protocols and routing methods designed expressly for IoT networks are also described, as well as simulation tools used to simulate and evaluate IoT systems. The discussion focuses on critical insights and consequences for the future of IoT, including challenges and potential in security, interoperability, edge intelligence, and sustainability. By tackling these obstacles and using emerging technologies, IoT can create disruptive change across businesses while also improving quality of life. This review seeks to give scholars, practitioners, and stakeholders a thorough grasp of IoT and its implications for the future
Reverse Osmosis Membranes for Desalination of Brackish Water
Reverse osmosis (RO), which is commonly used for different water purification and desalination applications, is a remarkable process to separate dissolved inorganic and organic compounds from water. Over traditional methods of water treatment and purification, RO has many benefits such as production of high quality drinking water, simultaneous elimination of multiple pollutants, and simple operation procedure. As drinking water supplies are declining and demand for high quality water is increasing worldwide, RO membrane based water treatments will most probably continue to develop.
This research was aimed at better understanding the behavior of the thin film composite (TFC) polyamide membrane used in RO process under various operating conditions. The performance of RO membrane was evaluated in terms of salt rejection and water flux to simulate brackish water desalination process. The operating conditions included salt concentrations ranging from 2000 to 6000 ppm and operating pressure ranging from 100 to 250 psi. Based on experimental results, the performance of the TFC polyamide RO membrane was estimated at higher operating pressures (300-1000 psi). Based on mass transfer coefficient , solute transport parameter and water permeability that is characteristic of the membrane. In addition, the potential of using the TFC RO membrane to process water during oil and gas productions (with 1.5-2.5 % salt by weight), was demonstrated in this study. Besides simulation, experiments were conducted using real water as the feed solution
Identification of a membrane binding peptide in the envelope protein of MHV coronavirus
Coronaviruses (CoVs) are enveloped, positive sense, single strand RNA viruses that cause respiratory, intestinal and neurological diseases in mammals and birds. Following replication, CoVs assemble on intracellular membranes including the endoplasmic reticulum Golgi intermediate compartment (ERGIC) where the envelope protein (E) functions in virus assembly and release. In consequence, E potentially contains membrane-modifying peptides. To search for such peptides, the E coding sequence of Mouse Hepatitis Virus (MHV) was inspected for its amino acid conservation, proximity to the membrane and/or predicted amphipathic helices. Peptides identified in silico were synthesized and tested for membrane-modifying activity in the presence of giant unilamellar vesicles (GUVs) consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), sphingomyelin and cholesterol. To confirm the presence of membrane binding peptides identified in the context of a full-length E protein, the wild type and a number of mutants in the putative membrane binding peptide were expressed in Lenti-X-293T mammalian and insect cells, and the distribution of E antigen within the expressing cell was assessed. Our data identify a role for the post-transmembrane region of MHV E in membrane binding
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Membrane binding proteins of coronaviruses
Coronaviruses (CoVs) infect many species causing a variety of diseases with a range of severities. Their members include zoonotic viruses with pandemic potential where therapeutic options are currently limited. Despite this diversity CoVs share some common features including the production, in infected cells, of elaborate membrane structures. Membranes represent both an obstacle and aid to CoV replication – and in consequence – virus-encoded structural and nonstructural proteins have membrane-binding properties. The structural proteins encounter cellular membranes at both entry and exit of the virus while the nonstructural proteins reorganize cellular membranes to benefit virus replication. Here, the role of each protein in membrane binding is described to provide a comprehensive picture of their role in the CoV replication cycle
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