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Symmetry of generalized rivalry network models determines patterns of interocular grouping in four-location binocular rivalry
Get PDFPreviously, symmetry of network models has been proposed to account for interocular grouping during binocular rivalry. Here, we construct and analyze generalized rivalry network models with different types of symmetry (based on different kinds of excitatory coupling) to derive predictions of possible perceptual states in 12 experiments with four retinal locations. Percepts in binocular rivalry involving more than three locations have not been empirically investigated due to the difficulty in reporting simultaneous percepts at multiple locations. Here, we develop a novel reporting procedure in which the stimulus disappears when the subject is cued to report the simultaneously perceived colors in all four retinal locations. This procedure ensures that simultaneous rather than sequential percepts are reported. The procedure was applied in 12 experiments with six binocular rivalry stimulus configurations, all consisting of dichoptic displays of red and green squares at four locations. We call configurations with an even or odd number of red squares even or odd configurations, respectively. In experiments using even stimulus configurations, we found that even percepts were more frequently observed than odd percepts, whereas in experiments using odd stimulus configurations even and odd percepts were observed with equal probability. The generalized rivalry network models in which couplings depend on stimulus features and spatial configurations was in better agreement with the empirical results. We conclude that the excitatory coupling strength in the horizontal and vertical configurations are different and the coupling strengths between the same color and between different colors are different. NEW & NOTEWORTHY Wilson network models of interocular groupings during binocular rivalry are constructed by considering features that indicate equal coupling strengths. Network symmetries, based on equal couplings, predict percepts. For a four-location rivalry experiment with red or green squares at each location, we analyze different possible Wilson networks. In our experiments we develop a novel reporting procedure and show that networks in which stimulus features and spatial configurations are distinguished best agree with experiments
Interaction between hydrogen sulfide, nitric oxide, and carbon monoxide pathways in the bovine isolated retina
Get PDFPurpose: Nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) are physiologically relevant gaseous neurotransmitters that are endogenously produced in mammalian tissues. In the present study, we investigated the possibility that NO and CO can regulate the endogenous levels of H2S in bovine isolated neural retina. Methods: Isolated bovine neural retina were homogenized and tissue homogenates were treated with a NO synthase inhibitor, NO donor, heme oxygenase-1 inhibitor, and/donor. H2S concentrations in bovine retinal homogenates were measured using a well-established colorimetric assay. Results: L-NAME (300 nM-500 μM) caused a concentration-dependent decrease in basal endogenous levels of H2S by 86.2%. On the other hand, SNP (10-300 μM) elicited a concentration-related increase in H2S levels from 18.3 nM/mg of protein to 65.7 nM/mg of protein. ZnPP-IX (300 nM-10 μM) caused a concentration-dependent increase in the endogenous production of H2S whereas hemin (300 nM-20 μM) attenuated the basal levels of H2S. Conclusion: We conclude that changes in the biosynthesis and availability of both NO and CO can interfere with the pathway/s involved in the production of H2S in the retina. The demonstrated ability of NO, CO and H2S to interact in the mammalian retina affirms a physiological/pharmacological role for these gaseous mediators in the eye
Loss of the tumor suppressor BIN1 enables ATM Ser/Thr kinase activation by the nuclear protein E2F1 and renders cancer cells resistant to cisplatin
No full textThe tumor suppressor bridging integrator 1 (BIN1) is a corepressor of the transcription factor E2F1 and inhibits cell-cycle progression. BIN1 also curbs cellular poly(ADP-ribosyl)ation (PARylation) and increases sensitivity of cancer cells to DNAdamaging therapeutic agents such as cisplatin. However, how BIN1 deficiency, a hallmark of advanced cancer cells, increases cisplatin resistance remains elusive. Here, we report that BIN1 inactivates ataxia telangiectasia mutated (ATM) serine/threonine kinase, particularly when BIN1 binds E2F1. BIN1 12A (a cancer-associated BIN1 splicing variant) also inhibited cellular PARylation, but only BIN1 increased cisplatin sensitivity. BIN1 prevented E2F1 from transcriptionally activating the human ATM promoter, whereas BIN1 12A did not physically interact with E2F1. Conversely, BIN1 loss significantly increased E2F1-dependent formation of MRE11A/RAD50/NBS1 DNA end-binding protein complex and efficiently promoted ATM autophosphorylation. Even in the absence of dsDNA breaks (DSBs), BIN1 loss promoted ATM-dependent phosphorylation of histone H2A family member X (forming γH2AX, a DSB biomarker) and mediator of DNA damage checkpoint 1 (MDC1, a γH2AX-binding adaptor protein for DSB repair). Of note, even in the presence of transcriptionally active (i.e. proapoptotic) TP53 tumor suppressor, BIN1 loss generally increased cisplatin resistance, which was conversely alleviated by ATM inactivation or E2F1 reduction. However, E2F2 or E2F3 depletion did not recapitulate the cisplatin sensitivity elicited by E2F1 elimination. Our study unveils an E2F1-specific signaling circuit that constitutively activates ATM and provokes cisplatin resistance in BIN1-deficient cancer cells and further reveals that γH2AX emergence may not always reflect DSBs if BIN1 is absent
Simultaneous LC–MS/MS analysis of simvastatin, atorvastatin, rosuvastatin and their active metabolites for plasma samples of obese patients underwent gastric bypass surgery
Get PDFStatins, HMG-CoA reductase inhibitors, are considered the first line treatment of hyperlipidemia to reduce the risk of atherosclerotic cardiovascular diseases. The prevalence of hyperlipidemia and the risk of atherosclerotic cardiovascular diseases are higher in obese patients. Published methods for the quantification of statins and their active metabolites did not test for matrix effect of or validate the method in hyperlipidemic plasma. A sensitive, specific, accurate, and reliable LC–MS/MS method for the simultaneous quantification of simvastatin (SMV), active metabolite of simvastatin acid (SMV-A), atorvastatin (ATV), active metabolites of 2-hydroxy atorvastatin (2-OH-ATV), 4-hydroxy atorvastatin (4-OH-ATV), and rosuvastatin (RSV) was developed and validated in plasma with low (52–103 mg/dl, /dl) and high (352–403 mg/dl, \u3e300 mg/dl) levels of triglyceride. The column used in this method was ACQUITY UPLC BEH C18 column (2.1 × 100 mm I.D., 1.7 μm). A gradient elution of mobile phase A (10 mM ammonium formate and 0.04% formic acid in water) and mobile phase B (acetonitrile) was used with a flow rate of 0.4 ml/min and run time of 5 min. The transitions of m/z 436.3 → 285.2 for SMV, m/z 437.2 → 303.2 for SMV-A, m/z 559.2 → 440.3 for ATV, m/z 575.4 → 440.3 for 2-OH-ATV and 4-OH-ATV, m/z 482.3 → 258.1 for RSV, and m/z 412.3 → 224.2 for fluvastatin (internal standard, IS) were determined by Selected Reaction Monitoring (SRM) method to detect transitions ions in the positive ion mode. The assay has a linear range of 0.25 (LLOQ) −100 ng/ml for all six analytes. Accuracy (87–114%), precision (3–13%), matrix effect (92–110%), and extraction recovery (88–100%) of the assay were within the 15% acceptable limit of FDA Guidelines in variations for plasma with both low and high triglyceride levels. The method was used successfully for the quantification of SMV, ATV, RSV, and their active metabolites in human plasma samples collected for an ongoing clinical pharmacokinetic and pharmacodynamic study on patients prior to and post gastric bypass surgery (GBS)
Educator’s Perceptions of the Impacts of School Violence on Caribbean Societies
Get PDFGlobally, school violence plays an ominous role in the education process as it has been widely recognized as having negative impacts. In this context, education in a violence-free environment is a challenge facing some schools, students and teachers in the Caribbean. Internationally, school violence is a relatively well researched area, however, both internationally and in the Caribbean, educator’s perceptions of the impacts of school violence is relatively understudied. This study explores educator’s perceptions of the impacts of school violence on Caribbean societies and offers an interpretive exploration of these perceptions. Self-administered questionnaires were randomly distributed to educators in Antigua and Barbuda, Barbados, Jamaica, St. Lucia, St. Vincent and the Grenadines and Trinidad and Tobago. To analyze the data, frequency distribution was used and the data converted into percentages. The results gleaned from one hundred and twenty respondents indicate that school violence has impacts at the individual, institutional and community levels
Understanding the Origins of Political Duopoly in Ghana’s Fourth Republic Democracy
Get PDFThe paper examines political party formation and fragmentation in Ghana. A multi-theory approach was used to explain the political party formation and fragmentations and why Ghana’s party politics in the Fourth Republic is being dominated by the de facto two-party system. The study adopts a content analysis approach and depends mainly on desk reviews of literature. Ghana’s experience shows that the evolution of political parties began with the formation of nationalist movements whose prime objective was to resist specific instances of colonial racism and exploitation. The fragmentation of political parties during the pre-independence era was because the parties held different philosophies and identities, and some of which seemed counterproductive to the prime objective of the nationalist movement. Thus, while some parties expressed sub-national or ethnic and regional identities, others were rooted in religious and supra-national cleavages. However, the fourth republican constitutional entrenchment of a multiparty political system in Ghana has therefore been stifled by the practical institutionalization of two-party system in the country. This may partly result in voter apathy among citizens especially those who are dissatisfied with the NPP and the NDC politics and may abstain from exercising their voting rights
Static Advertising Vs Dynamic Advertising and their Impact on the Fashion Industry
Get PDFThis Senior Honors Thesis explored the idea of static advertising and dynamic advertising in the fashion industry. It discussed the similarities and the differences between the two styles of advertising (with an emphasis on the fashion industry), gave examples of both styles of advertising and explained the results of the research plan initiated to understand how static advertising and dynamic advertising impacts the fashion industry within our current society. Participants for the research plan included twelve Texas Southern University students that were split into four categories: Marketing Majors, Business Majors, Fashion Entrepreneurs and Other Majors. Throughout the Spring 2019 semester, each student was given an in-person interview to understand their knowledge of static advertising and dynamic advertising and to receive their opinion about the two advertising styles\u27 use in the fashion industry for our current society. Results are discussed in terms of qualitative data, showcased in various tables, based off of the answers given in the interviews
Translational Strategies For Improving Medication Counseling In Community Pharmacy Practice
Get PDFWith the continual existence and burden of medication errors and the expansion of the pharmacist\u27s role (n patient counseling as a means to combat this issue, there is still much to evaluate and resolve in regards to this matter. Regardless of the reason that these errors still occur, be it contributed to blatant neglect of duty or perhaps an educational gap, this problem is critical to resolve as the consequences often lead to financial, personal, and potentially fatal outcomes that can rarely receive full rectification. This study evaluated a first year pharmacy class after their completion of a pharmacy practice course focusing on patient counseling. The results were then analyzed to discover any areas or gaps that can be addressed and improved which ultimately, once mended, could yield more competent future pharmacists and pharmacist interns in the practice of patient counseling, thus reducing the occurrence of medication errors.
This study utilized a self-assessed confidence survey following the student\u27s completion of their pharmacy practice course. The confidence survey was comprised of four categories in patient counseling with each category consisting of various skills pertaining to that specific category: Introductions, Assessing Patient Knowledge, Use of Visual Aids and Demonstrations, Key Counseling Information. A demographics section was also included in the confidence survey. Each skill of the confidence survey was graded on a Likert Scale of 5 where a grade of 1 represented no confidence and 5 represented complete confidence.
The results of the confidence survey revealed that 50% or more of the participants expressed very confident or compete confidence in all skills for each category of patient counseling, although some skills yielded results slightly less than 50% of participants on aforementioned confidence levels: very confident or complete confidence.
The pharmacy practice lab course (PHAR-411) and its teaching methods utilized was effective overall in producing first-year pharmacy students with strong confidence levels in the realms of patient counseling
A Comprehensive Financial Analysis of Retail and Wholesale Food Chains
Get PDFThis Financial Analysis Report serves as a financial instrument taking an introspective view into two dynamic companies in the retail and grocery industry. Both Kroger and Costco Wholesale have consistently managed to maintain a reputable career as two large industrial organizations. These two companies have had a magnitude of success by their way of operations in such a competitive market. First, looking at each company\u27s history and way of operations we discovered different strategies utilized between Kroger and Costco. Kroger, a supermarket chain centralizes on effective manufacturing and processing of foods sold in their various supermarkets. They experienced a 6.35% sales growth from 2017 and has become a national powerhouse in supermarkets. Utilizing financial principals attainted in classes I have taken in the business school, some key findings where we discovered that there is a close profit margins between the two companies, sustainability differences with operating profit margin and overall performance differences. Evaluating both companies with different rations, computations and accounting methods gave us the financial data needed to understand how each company operates and their areas of strengths and weaknesses