Language Acquisition and Various Influences on Student Learning Essay

Language Acquisition and Various Influences on Student Learning - Essay Example This essay declares that children invent the learning rules through making initial mistakes and correcting themselves as they develop. Various aspects of language acquisition have been identified by theorists that make it a biologically controlled process. Two of these aspects are significant for language educators in creating an environment that promotes learning among students. Firstly, it has to be stressed that language acquisition is innate and it is not generated by external events. However, its development requires a rich environment that exposes the learner more to the language. Secondly, it is also noted that direct teaching and intensive practice do not have significant positive effects on the language acquisition process. These aspects imply that a proper language acquisition will then be enhanced through creation of some classroom environment that favors interaction between the students themselves. This paper discusses that developing such a climate will involve examination different factors affecting learning and their mutual relations. The influence of social and emotional factors on the learning process can no longer be ignored. Such negligence results in the development of some instructional gap and the students attempt to fill this gap in their devised mechanisms that do not support the learning process. Some degree of mutual relationship occurs among intellectual, social, and emotional processes as they affect the learning process. ... The learning process occurs in some social context that is dynamic in nature so that an individual with complex cognition will be able to learn and adapt to the changing needs of the social contexts of learning as opposed to the less complex individuals (Love & Love, 1996). Aspects of the social setup such as the culture of a community may affect a student’s beliefs, attitudes, or motivations towards the learning process. These are detrimental to the learning process if carried into the classroom environment. On the other hand, the individuals with complex cognition have better skills of understanding the perspectives of other people. This implies that good cognition can help students adapt to new social settings, which is essential for learning. The relationship between cognition and the social process is also evident in classroom discussions. A good proportion of learning in students occurs in the classroom discussions, where students share their experiences that they feel t he other individuals need to learn. Through the discussions, a student is able to learn more of the concept or determine if it is well understood Emotions also have effects on the learning and development processes in students since the feeling states, and thinking states cannot be separated easily (Love & Love, 1996). The emotional and rational minds of an individual often act in a balanced manner to guide the individual through life decisions. While emotions will strive to inform and guide the rational operations, rational mind will try to refine the input from emotional mind before initiating an operation (Love & Love, 1996). Negative emotions such as depression, when carried into the classroom, will suppress the learning process. The students will not be able to

Nursing Research Utilization Project Proposal Essay

Nursing Research Utilization Project Proposal - Essay Example 5). ESRD and ESRF is diagnosed when the patient loses 85% to 90% of kidney function, which necessitates dialysis, because kidneys can no longer remove toxins from the blood. Dialysis circulates blood on one side of a semipermeable membrane, while the other side circulates dialysis fluid. (Answers.com). Patients on dialysis have to spend four hours, three times a week, which makes dialysis treatment very demanding for the patient (Sonnier, 2000, p. 5). ... Information reinforcement techniques worked in the Barnett (2007) study - after 26 weeks, this group reduced their average IDWG from 2.64 kg to 2.21 kg, and the rate of fluid adherence increased from 47% to 71.5% (Barnett et al. pp. 304-305). Cognitive behavioral therapy has proven effective in the research – for instance, a study conducted by Christensen et al. (2002). In this study the intervention group received a protocol of 9 steps. In this protocol, the patients were taught about self-monitoring, setting goals, coping, reinforcement, and evaluation (Christensen et al., 2002, p. 393).   Their study proved to be effective after 8 weeks – the control group gained around 3.3 pounds, while the intervention group lost around 3 pounds (Christensen, et al., 2002, p. 396).  Ã‚   Behavioural modification is another model that has been studied with regards to dialysis patients and compliance with protocols and regimens. For instance, a study by Hegel et al. (1992) found that the reinforcement produced the greatest drop in IDWG, and that this drop in IDWG was persistent over time – the IDWG continued to be lowered two months after the intervention, even though, during this period of time, the patients only received information about graphing and monitoring (Hegel et al., 1992, p. 326). It is feasible to implement into a work setting, as there is not a need for special equipment. There is a need for special training, but the methods are easy to learn and implement. Because of this, it would be consistent with community culture and resources, because it would not be overly taxing for resources. Introduction When patients have certain diseases, such as hypertension or diabetes, they

Song analysis Essay Example | Topics and Well Written Essays - 1250 words

Song analysis - Essay Example The song in question, written and produced by a group known as â€Å"Aviation† and entitled â€Å"You were my Everything† will be the focus of this particular analysis. It is the hope of this author that the reader will gain a more informed understanding with relation to the ideas and core levels of understanding/emotions that the songwriter attempted to convey; rather than merely a cursory level of understanding with respect to the fact that a simple love song has been represented. In much the same way that a literary critique seeks to focus a level of discussion and analysis upon the mechanisms that the writer uses, the core themes that are leveraged, and the use of language as a means of promoting understanding; the following analysis will engage in much the same manner of consideration with regards to this particular song. Firstly, the song itself starts with a brief introit that is spoken rather than sung. Although this may not seem as an important aspect of analyzing the particular song, it serves a vital function as it helps to set the stage with respect to the information that will be presented, the tone, and the ultimate understanding that can be drawn from the contents of the song. Beginning by stating that the singer has lost something that is dear to him, the listener is instantly engage with the understanding that love loss and the hope of gaining at once again will come to be represented within the song itself. However, another element that is presented directly before the singing commences has to do with the frustration and inability of the singer/songwriter to express his emotions in any other way. Out of exasperation, the singer finally says â€Å"it’s just†¦I don’t even know – just listen†¦Ã¢â‚¬ . This level of hopelessness with regards to seeking to expl ain the position that the singer/songwriter understands only all too well but is probably quite difficult for anyone else to engage helps to foreshadow the angst and

Racing Essay Example | Topics and Well Written Essays - 250 words

Racing - Essay Example Hence, only those with an unyielding attitude are found willing to accept struggles and unceasingly proceed with the race. Though it typically pertains to a sport in which racers compete for speed and strategizing at the maximum speed to emerge as the first on the finish line, people in general form varying connotations about ‘racing’. Often times, racing is valued for the idea that life is only lived once so one should seize every opportunity that comes his way. It becomes worthwhile as well to consider that racing may represent people who are optimistic enough to not lose heart with their depressed conditions and keep the race with life instead, positively hoping for recovery no matter what it takes. To others, racing is a means to demonstrate potentials of being tough amidst crises or in contending against an opponent who wishes to maintain a tight competition, hence, only those with an unyielding attitude are found willing to accept struggles and unceasingly proceed with the race.Perhaps it is through the ambiguity of the term ‘racing’ that the world has been led to further inclination and fondness of a racing sport in view of its associated principles which are applicable to a person’s life. As it turns out, the fascination to reach a goal or beat the rest who go after the same goal creates the basic idea about racing which eventually serves as a guide for a racer to live a life of purpose regardless of the type of field or endeavor chosen.

Song analysis Essay Example | Topics and Well Written Essays - 1250 words

Song analysis - Essay Example The song in question, written and produced by a group known as â€Å"Aviation† and entitled â€Å"You were my Everything† will be the focus of this particular analysis. It is the hope of this author that the reader will gain a more informed understanding with relation to the ideas and core levels of understanding/emotions that the songwriter attempted to convey; rather than merely a cursory level of understanding with respect to the fact that a simple love song has been represented. In much the same way that a literary critique seeks to focus a level of discussion and analysis upon the mechanisms that the writer uses, the core themes that are leveraged, and the use of language as a means of promoting understanding; the following analysis will engage in much the same manner of consideration with regards to this particular song. Firstly, the song itself starts with a brief introit that is spoken rather than sung. Although this may not seem as an important aspect of analyzing the particular song, it serves a vital function as it helps to set the stage with respect to the information that will be presented, the tone, and the ultimate understanding that can be drawn from the contents of the song. Beginning by stating that the singer has lost something that is dear to him, the listener is instantly engage with the understanding that love loss and the hope of gaining at once again will come to be represented within the song itself. However, another element that is presented directly before the singing commences has to do with the frustration and inability of the singer/songwriter to express his emotions in any other way. Out of exasperation, the singer finally says â€Å"it’s just†¦I don’t even know – just listen†¦Ã¢â‚¬ . This level of hopelessness with regards to seeking to expl ain the position that the singer/songwriter understands only all too well but is probably quite difficult for anyone else to engage helps to foreshadow the angst and

Verification vs Validation Essay Example for Free

Verification vs Validation Essay Verification ensures that the system (software, hardware, documentation, and personnel) complies with an organization’s standards and processes, relying on review of non-executable methods. Validation physically ensures that the system operates according to plan by executing the system functions through a series of tests that can be observed and evaluated. Verification answers the question, â€Å"Did we build the right system?† while validation addresses, â€Å"Did we build the system right?† Verification requires several types of reviews, including requirements reviews, design reviews, code walkthroughs, code inspections, and test reviews. The system user should be involved in these reviews to find defects before they are built into the system. In the case of purchased systems, user input is needed to assure that the supplier makes the appropriate tests to eliminate defects. Validation is accomplished simply by executing a real-life function. This includes unit testing, integration testing, system testing and user acceptance testing. In this rigorous testing is conducted to validate if the system meets the functional requirement. The three most important skills that a system analysis should have are the same for any company. They should first and foremost have people skills. You have to be able to work with a variety of people and be able to work in teams. You should be an assertive person also. A good systems analysis should be able to take initiative and do things without being told. Also this person should have good reasoning and problem solving skills. These are all things that should be within the person naturally along with the actual computer skills necessary to analyze systems for a client. -are ability to work well with others, -good communication skills, -the ability to ask the right questions Bidder Responsibility Determination: To be determined responsible, a bidder must be successfully evaluated against the 7 following criteria: 1. Financial Resources. The bidder must have adequate financial resources to perform the contract, or the ability to obtain them (see FAR 9.104-3(a)—Ability to Obtain Resources). 2. Performance Schedule. The bidder must be able to comply with the performance schedule, required or proposed delivery, taking into consideration all existing commercial and governmental business commitments. 3. Performance Record. The bidder must have have a satisfactory performance history, if any (see FAR 9.104-3(b)—Satisfactory Performance Record and Experience Certificate). Nevertheless, a prospective contractor shall not be determined responsible or non-responsible solely because of a lack of relevant performance history, except when specified in a standard for special acquisitions. 4. Integrity and Ethics. The bidder must have a satisfactory record of integrity and business ethics including satisfactory compliance with laws related to taxes, labor and employment, environment, antitrust, and consumer protection (see FAR 9.406-2—Causes for debarment and FAR 9.407-2—Causes for suspension). 5. Organization and Skills. The bidder must have the necessary organization and skills, experience, accounting and operational controls, and technical skills, or the ability to obtain them (see FAR 9.104-3(a)—Ability to Obtain Resources). 6. Equipment and Facilities. The bidder must have the necessary technical equipment and facilities for production or construction, or ability to obtain them (see FAR 9.104-3(a)—Ability to Obtain Resources); and 7. Other Qualification. The bidder must be otherwise qualified and eligible to receive an award under applicable laws and regulations. Systems Engineering V Model The system life cycle The system life cycle has seven phases: (1) discovering system requirements, (2) investigating alternatives, (3) full-scale engineering design, (4) implementation, (5) integration and test, (6) operation, maintenance and evaluation and (7) retirement, disposal and replacement. However, the system life cycle is different for different industries, products and customers. State the problem The problem statement starts with a description of the top-level function that the system must perform or the deficiency that must be ameliorated. It includes system requirements stated in terms of what must be done, not how to do it. It might be composed in words or as a model. Inputs come from end users, operators, bill payers, owners, regulatory agencies, victims, sponsors, Marketing, Manufacturing, etc. These are called stakeholders. In a modern business environment, the problem statement starts with a reason for change followed by vision and mission statements for the company. Understand customer needs Customers seldom know what they want or need. Systems Engineers must enter the customers environment and find out how the customer will use the system. Talking to your customers customer and your suppliers supplier can be very useful. Frameworks, such as the Zachman framework or the DoDAF, are useful for seeing how the system fits into the customers enterprise. Discover system requirements There are two types of system requirements: mandatory and tradeoff Mandatory requirements insure that the system satisfies the customers operational need, and must be passed or failed, there is no middle ground. The tradeoff requirements are evaluated to determine the preferred designs, and should state conditions that would make the customer happier. Verify and validate requirements Investigate alternatives Alternative designs are evaluated based on performance, cost, schedule and risk criteria. This analysis should be redone whenever more data are available. Define quantitative measures Performance and cost criteria show how well the system satisfies its requirements, e.g., In this test the car accelerated from 0 to 60 in 6.5 seconds. Technical performance measures (TPMs) are made during the design and manufacturing process to evaluate the likelihood of satisfying the system requirements. Model the system Models will be developed for most alternative designs. Many types of system models are used, such as block diagrams, functional flow diagrams, object-oriented models, computer simulations. Design the system The overall system must be partitioned into subsystems, subsystems must be partitioned into assemblies, etc. Reusability should be considered in creating subsystems. For new designs, subsystems should be created so that they can be reused in future products. For redesign, subsystems should be created to maximize the use of existing, particularly commercially available, products. Systems engineers must also decide whether to make or buy the subsystems, first trying to use commercially available subsystems. If nothing satisfies all the requirements, then modification of an existing subsystem should be considered. If this proves unsatisfactory, then some subsystems will have to be designed in-house. Flexibility is more important than optimality. Hardware, software and bioware must be considered. Bioware (or wetware) means humans and other biological organisms that are a part of the system. For example, in designing a race track the horses or dogs are a part of the bioware. Create sequence diagrams Define system architecture Some choices that have to be made: (1) object-oriented design, structured analysis, or functional decomposition, (2) distributed or centralized computing, (3) commercial off the shelf (CoTS) or custom designed. Functional analysis Systems engineers do functional analysis on new systems (1) to map functions to physical components, thereby ensuring that each function has an acknowledged owner, (2) to map functions to system requirements, and (3) to ensure that all necessary tasks are listed and that no unnecessary tasks are requested. This list becomes the basis for the work breakdown structure. A work breakdown structure (WBS) breaks a project into smaller, more manageable components. Sensitivity analyses Sensitivity analyses can be used to point out the requirements and parameters that have the biggest effects on cost, schedule and performance. They are used to help allocate resources. Assess and manage risk There are two types of risk: risk of project failure (due to cost overruns, time overruns or failure to meet performance specifications) and risk of harm (usually called personnel safety). A failure modes and effects analysis and risk mitigation must be performed. Project risk can be reduced by supervising quality and timely delivery of purchased items. Reliability analysis Major failure modes must be analyzed for probability of occurrence and severity of occurrence. Integrate system components Integration means bringing things together so they work as a whole. System integration means bringing subsystems together to produce the desired result and ensure that the subsystems will interact to satisfy the customers needs. End users and engineers need to be taught to use the system with courses, manuals and training on the prototypes. Design and manage interfaces Interfaces between subsystems and interfaces between the main system and the external world must be designed. Well-designed subsystems send finished products to other subsystems. When designing subsystems and their interfaces be sure to consider reuse. Launch the system Launching the system means doing what the system was intended to do, e.g. running the system and producing outputs. Configuration management Configuration management (also called modification management) ensures that any changes in requirements, design or implementation are controlled, carefully identified, and accurately recorded. All stakeholders should have an opportunity to comment on proposed changes. Decisions to adopt a change must be captured in a baseline database. Baselines can only be changed at specified points in the life cycle. The phrase requirements tracking is now being used for an important subset of configuration management. Project management Project management is the planning, organizing, directing, and controlling of company resources to meet specific goals and objectives within time, within cost and at the desired performance level. Project management creates the work breakdown structure, which provides structure for guiding team assignments and cost and tracking control. Documentation All of these Systems Engineering activities must be documented in a common repository, often called the Engineering Notebook. The stored information should be location, platform, and display independent: which means any person on any computer using any tool should be able to operate on the fundamental data. Assumptions, results of tradeoff studies and the reasons for making critical decisions should be recorded. These documents should be alive and growing. For example, at the end of the system life cycle there should be an accurate model of the existing system to help with retirement. Lead teams Complex systems cannot be designed by one person. Consequently engineers work on Integrated Product Development Teams (IPDTs). These teams are interdisciplinary with members from Business, Engineering, Manufacturing, Testing, etc. IPDTs are often led by Systems Engineers. Assess Performance During the operation and maintenance phase of the system life cycle the performance of the system must be measured. Initially these measurements will be used to verify that the system is in compliance with its requirements. Later they will be used to detect deterioration and initiate maintenance. Prescribe tests Early in the system life cycle Systems Engineering should describe the tests that will be used to prove compliance of the final system with its requirements. However, most testing should be performed by built-in self-test equipment. These self-tests should be used for initial testing, post-installation testing, power-up diagnostics, field service and depot repair. The recipient of each test result and the action to be taken if the system passes or fails each test must be stated. Conduct reviews Systems Engineering should ensure that the appropriate reviews are conducted and documented. The following set is common: Mission Concept Review, System Requirements Review (SRR), System Definition Review, Preliminary Design Review (PDR), Critical Design Review (CDR), Production Readiness Review (PRR), and System Test. Full-scale engineering design begins after the Preliminary Design Review. Manufacturing begins after the Critical Design Review. Total system test The system that is finally built must be tested to see (1) that it satisfies the mandatory requirements, and (2) how well it satisfies the tradeoff requirements. Re-evaluation Re-evaluation is arguably the most important task of Systems Engineering. For centuries engineers have used feedback to control systems and improve performance. It is one of the most fundamental engineering tools. Re-evaluation means observing outputs and using this information to modify the system inputs, the product or the process. Re-evaluation should be a continual process with many parallel loops. Everyone should continually re-evaluate the system looking for ways to improve quality. Tools used in this process include basic systems engineering, and the quality engineering techniques presented by, for example, Deming and Taguchi. Deming (1982); Bicknell and Bicknell (1994); Latzko and Saunders (1995). Near the end of the project, engineers should write a Lessons Learned document. These lessons learned should not be edited by management, because management could trivialize what they do not understand or omit management mistakes. Categories of Systems Engineers Many companies divide their Systems Engineers into three categories according to their major workflows: requirements definition, architectural design and testing and verification. Creating Systems Engineers The traditional method of creating Systems Engineers was to select well-organized engineers with lots of common sense and let them acquire 30 years of diverse engineering experience. But recently these traditional Systems Engineers have written books and standards that explain what they do and how they do it. So now that the tools, concepts and procedures have been formalized, in four years of undergraduate education we can teach Systems Engineers who will have performance levels 50% that of traditional Senior Systems Engineers. Ten years of systems engineering experience will improve performance to 80% and another ten years will increase it to 100%.

Middle Cerebral Artery Aneurysm Identification

Middle Cerebral Artery Aneurysm Identification Middle cerebral artery is a very common site for aneurysm formation. MCA aneurysms represent 18-40 of all intracranial aneurysms. MCAAS are commonly divided into three groups: proximal (M1As), bifurcation (MbifAs), or distal (MdistAs) aneurysms. Each group presents with distinct anatomic features that have an impact on their management. Assigning MCAAs into a particular group can sometimes be difficult since the length and caliber of the M1 segment often varies and there may be two or more major branching sites along its course. This has led to fallacies in sub-grouping of MCAAs with resultant high variability in the reported frequencies of the different subgroups: M1As (2 61%) and MbifAs (39 90%), of all MCAAs [2, 3, 5-8]. Preoperative identification of MCA aneurysm origin either at the main MCA bifurcation (Mbif) or at another branching point has a great implication on surgical planning as different groups of MCAAs pose different challenges to the neurosurgeon requiring different surgical strategies. In this report, we present our technique for accurate identification of the MCA main bifurcation from other branching points along MCA as a key for a more accurate classification of MCA aneurysms. Furthermore we suggest an extension to the classic MCA classification. Also, we present the distribution of 1309 MCA aneurysms as a part of the largest CTA anatomic study, so far, for MCA aneurysms. Our aim is to help recognize the branching pattern of MCA with special emphasis on the exact characterization of MCA main bifurcation. Patients and methods Patients and radiological data: Data were retrieved from a prospectively collected database that sequentially encompassed all patients with intracranial aneurysms admitted to the Department of Neurosurgery at Helsinki University Central Hospital (catchment area, 1.8 million people). We identified 1124 consecutive patients with MCA aneurysms diagnosed between 2000 and 2009. We excluded 115 patients from the study due to lack of adequate CTA (98 cases) or having non-saccular MCAAs (17 cases). The remaining 1009 patients with a total of 1309 saccular MCA aneurysms had adequate cerebral CTAs. The routine use of CTA (GE Lightspeed QX/i; GE Medical Systems, Milwaukee, WI) started in the year 2000 and has been the primary imaging modality for cerebral aneurysms at our institution ever since. CTA is rapid, safe, readily available and can provide 3D reconstruction of vessels and bony structures. Each patient`s radiological images were stored in the hospitals central digital archiving system (PACS; AGFA, IMPAX, version 4.5), launched in 1998, from which all of the relevant diagnostic images were recalled. Nomenclature: For each patient, pretreatment CTA images were evaluated and measured on screen (AGFA, IMPAX DS 3000). The MCA aneurysms were identified in each patient and classified according to the location of aneurysm neck in relation to the main MCA bifurcation (fig.6). MCA aneurysms were grouped into three groups: M1As, aneurysms on the main trunk (M1) of the MCA, between the bifurcation of internal carotid artery (ICA) and the main MCA bifurcation; MbifAs, aneurysms at the main MCA bifurcation; MdistAs, aneurysms distal to main MCA bifurcation on M2, M3 or M4 segments. Then M1As were sub-grouped into 2 groups: M1-ECBAs, aneurysms arising at the origin of early cortical branches; M1-LSAAs, aneurysms arising at the origin of Lenticulostriate arteries. The M1-ECBAs comprised aneurysms arising at the origin of early frontal branches (M1-EFBAs) and aneurysms arising at the origin of early temporal branches (M1-ETBAs). CTA for precise recognition of MCA main bifurcation For localization of Mbif, we simply examine the MCA branches in sagittal views of CTA at the insular level and detect the insular trunks from direction and course then follow these trunks till their essential meeting at the Mbif. This pilot examination must be correlated with examination of axial and coronal views for accurate confirmation. In some cases with difficult branching and looping patterns, 3D reconstruction is necessary. CTA for accurate classification of aneurysms along MCA: (figures 2-6) We examine the direction and course of the branches originating at the neck of the aneurysm in sagittal views to know whether these branches are cortical or insular. Correlation with axial and coronal views and sometimes 3D reconstructions is necessary. Then we check the relation of this branching point to the MCA main bifurcation (the primary meeting point of insular trunks) for correct sorting of the aneurysm. Results: Demographics: The mean age at diagnosis in our patient population was 54 years (range 13-89 y). The number of women 690 (68%) doubled that of men 319 (32%). Aneurysms were more common on the Rt. MCA 732 aneurysms (56%) than on the lt. MCA 577 aneurysms (44%). In 466 (46%) Patients, there were one or more additional aneurysms totaling 1761 aneurysms. Classification of MCA aneurysms: Table 1 shows the distribution of 1309 aneurysms along MCA. The number of aneurysms arising at the MCA main bifurcation (MbifAs) 829 (63%) doubled the total number of all aneurysms arising along M1 segment (M1As) 406 (31%). The distal MCA aneurysms (MdistAs) were the least frequent group only 74 (6%). Around three quarters (77%) of ruptured MCA aneurysms and 57% of unruptured MCA aneurysms were located at the MCA bifurcation. Types of M1As: Aneurysms arising along the main trunk of MCA (M1As) were grouped into 2 groups according the nature of the branches taking off at the base of the aneurysms. Among the 406 M1As, 242 (60%) aneurysms arose at the origin of early cortical branches from M1 segment (M1-ECBAs) while the remaining 164 (40%) M1As were not associated with early cortical branches but LSAs (M1-LSAAs). The aneurysms at the origin of early cortical branches (M1-ECBAs) comprised 178 aneurysms at the origin early frontal branches (M1-EFBAs) and 64 aneurysms at the origin of early temporal branches (M1-ETBAs). Discussion: The high variability in the reported frequencies of different groups of MCA aneurysms (M1As, 2-61%; MbifAs, 39-90%)[2, 3, 5-8] could be attributed to falsies in classification of these aneurysms and / or obtaining such incidences from small statistically unreliable series. In a trial to resolve this issue in a large statistically reliable non-selected group of MCAAs, We performed a retrospective anatomical study of CTAs for consecutive 1009 patients with 1309 saccular MCAAs aneurysms. We tried to find and follow the objective characteristics of branching points along MCA to be more precise when classifying MCA aneurysms. In our previous MCA publications [1-4, 9]we have followed the classic classification of MCA aneurysms. Recognizing the importance and the deceptive appearance of the early cortical branches, we have added an extension to the traditional classification by subdividing M1 aneurysms into M1-ECBAs and M1-LSAAs. This proofed helpful to keep attention to this previously und erestimated group of aneurysms arising at the origin of early cortical branches (M1-ECBAs). Preoperative identification of MCA aneurysm origin either at the main bifurcation or at another branching point has an implication on surgical planning especially for ruptured MCAAs as different type of MCAAs poses different challenges to the neurosurgeon requiring different surgical strategy[1-3]. Also when selecting the recipient vessel for bypass surgery if indicated to compensate for an inevitable vascular compromise during securing the aneurysm. MCA is classically subdivided into 4 segments: the sphenoidal (M1) segment extending from ICA bifurcation to the main MCA bifurcation where insular trunks (M2) begins and course over the insula till the peri-insular sulci where the opercualar (M3) segments start and course till the lateral surface of the brain in the sylvian fissure then continue as parasylvian (M4) segments whose distal extensions are sometimes called the terminal (M5) segments [10-13]. Although Yasargil used the main MCA bifurcation as the demarcation point between M1 and M2 segments, Rhoton used the MCA genu at the limen insulae as the demarcation point between M1 and M2 segments, hence he had prebifuration M1 and post bifurcation M1[8, 14]. Aneurysms along MCA are classically divided into three groups: proximal (M1As), bifurcation (MbifAs), or distal (MdistAs) aneurysms. It is evident that the identification of the MCA main bifurcation is the key for accurate classification and grouping of these aneurysms. Although MCA anatomy has been widely described in standard anatomy, neuroradiology, and neurosurgery textbooks[8, 15-17], it is still not uncommon to mistaken the identification of the main MCA bifurcation from other branching points along the main trunk of MCA particularly those associated with a large-caliber cortical branch. This misconception led to wide range of the reported length of MCA main trunk (0 -30 mm) and large differences in the reported relative frequency of M1As (2 61%) and MbifAs (39 90%) between authers[2, 3, 5-8]. Accurate identification of the MCA main bifurcation: Crompton named the cortical branches arising from M1 segment proximal to MCA bifurcation as early branches. Yasargil and colleagues defined the origin of the large cortical branches arising proximal to the most lateral LSAs as (false early bifurcation) and declared that aneurysms arising at this region of M1 could be mistakenly diagnosed as MCA bifurcation aneurysms. They stressed the importance of the LSAs in defining the site of the main bifurcation as the main bifurcation is usually located distal to the origin of LSAs [8, 12, 13]. These early cortical branches are found in nearly 85 to 90% of hemispheres [14]. In the anatomical study for the early branches of MCA, Rhoton and colleagues found that the early branches arising on the proximal half of the main trunk of MCA resembled postbifurcation trunks of M1 in some aspects with possibility of being misinterpreted as postbifurcation trunks of the M1 leading to false localization of the main bifurcation. They could identify LSAs on M1 segment distal to the origin of these early branches. MCA main bifurcation was identified proximal to the genu in 82%, at the level of genu in 8%, and distal to the genu in 10% of hemispheres [14]. It is obvious that the exact identification of MCA main bifurcation is the key for correct sorting of aneurysms along the MCA. It is popular to subjectively accept a branching point close to MCA genu giving rise to the largest branches as the MCA main bifurcation. It is also not uncommon to feel more internal confidence when such a branching point holds an aneurysm to consider it as MCA main bifurcation. This might be correct in the majority of cases but unfortunately it would be misleading in some cases. The idea for identification of the main MCA bifurcation (Mbif) accurately is to find a constant criterion for Mbif which can be used as a hallmark for identification of Mbif from other branching points along the MCA with high certainity. Keeping into mind that Mbif might share some characteristics (like size of out-coming branches, location in relation to MCA genu and relation to LSAs) with other branching points along MCA preclude accepting any of these characteristics as a hallmark for Mbif. The fact that all insular trunks (M2s) authentically originate from one point that is the MCA main bifurcation, means that the primary meeting point of all insular trunks (M2s) can be considered as a hallmark for Mbif. So, simply by identifying the insular trunks and following them proximally till their original meeting into one point, the Mbif can be localized accurately and with certainty. Insular (M2) trunks cannot be identified by being the largest branches as early cortical branches are sometimes of the same caliber or even larger than the actual M2 trunks. M2 trunks run along the insula from the limen insula for a variable distance taking the superior and posterior directions. So by observing the direction and course of each of the branches originating from the MCA trunk in sagittal, coronal and axial CTA views, it will be easy to identify the insular trunks and to follow them proximally till their authentic meeting at the Mbif. In fewer words, considering that the main MCA bifurcation is not always distal to the origin of LSAs or always proximal or at the genu, but it always gives insular trunks (M2s) means that identification of the primary starting point of these insular trunks will guide to the main MCA bifurcation. These insular trunks should be recognized by their course over the insula for variable distance not by their size as some early cortical branches might be of similar or even larger size. Among all the aneurysms arising along MCA, those aneurysms arising from M1 segment at the origin of early cortical branches (ECB) are more likely to be misdiagnosed as a bifurcation aneurysm especially when the cortical branch is large and arises close to the MCA genu. The fact that early temporal branch becomes smaller as it arises closer to genu[14]means that it would not be common to misinterpret an aneurysm arising at the origin of an early temporal branch as a bifurcation aneurysm even if it is close to genu. There is no relation between the size of EFB and its distance from the genu. In angiograms, such large frontal branches look very similar to post bifurcation M2 trunks. This shows clearly how some aneurysms arising at the origin of large early frontal branches (EFB) could be, if enough attention was not paid, misclassified as MCA bifurcation aneurysm especially when close to the MCA genu. Ulm et al.[7] unexpectedly found, in their anatomical retrospective study of MCAAs with special emphasis on those aneurysms arising from M1 at the origin of early cortical branches, that M1As arising at the neck of EFB were more common than MbifAs and they claimed that many of EFB aneurysms were misclassified as early MbifAs reasoning why MbifAs were reported in previous pubilcations to be the most common location for MCAAs. This was contrary to our and general experience of Mbif being the most common location for MCAAs [1-5, 13, 18]. During this study, it was easy to sort some aneurysms along MCA, such as a small aneurysm at the origin of LSAs close to ICA bifurcation or a small aneurysm along M4 segment, precisely from the first look. Unfortunately, the biggest percentage of MCA aneurysms arose close to the MCA genu at some branching points which included early cortical branches, MCA main bifurcation and early furcation of M2 branches. This necessitated a lot of work to discriminate between these branches for precise sorting of MCA aneurysms. Moreover, some morphological characteristics of the aneurysms, such as large aneurysm size and complex projections, added to the difficulty for proper distinguishing of these branches. The task was more difficult for ruptured MCA aneurysms especially when associated with large ICH distorting the anatomy. On the other hand the availability of the 3D reconstructions, which made it possible to examine the aneurysms and MCA branches from different angles, together with the clas sic CTA views paved the way to accomplish our goal for sorting MCA aneurysms accurately with high degree of certainty. The present work shows, in harmony with our previous publications (table 3), that MCA bifurcation is the most common location for aneurysms along the MCA. The number of MbifAs 829 (63%) doubled the total number of all M1As 406 (31%) including those aneurysms arising at the origin of LSAs and those at the origin of ECBs. MCA bifurcation aneurysms comprised 77% of ruptured MCA aneurysms and 57% of unruptured MCA aneurysms. Among the 406 M1As, 178 (44%) aneurysms arose at the origin of early frontal branches (M1-EFBAs). The diameter of the associated early frontal branch was à ¢Ã¢â‚¬ °Ã‚ ¥ half the diameter of M1 in 106 (60%) cases. We assume that such aneurysms, without careful examination, might be misclassified as MbifAs especially when the associated large EFB is close to the genu of MCA. Early temporal branches were associated with 64 (16%) aneurysms (M1-ETBAs). The remaining 164 (40%) M1As were not associated with early cortical branches but with LSAs (M1-LSAAs). (Table 2) At the end of this study we realized that many M1 aneurysms arising at the origin of large early cortical branches especially EFB could be sometimes misclassified as MbifAs, but Mbif is still the most common location for aneurysms along MCA. We agree with Ulm et al [7] for the possibility to mistaken EFB aneurysms as bifurcation aneurysms if much care was not paid, but we assume that their surprising results of EFB being the most common location for MCAAs came from the small number of the cases included in their study. (Table 4) Conclusion: Careful objective analysis of MCA branching pattern from preoperative CTA is very important to understand patient-specific vascular anatomy which aids the surgeon to successfully exclude MCAAs from the circulation while preserving the surrounding vasculature. Although many M1 aneurysms arising at the origin of large early cortical branches especially EFB could have been misclassified as MbifAs in previous reports, Mbif is still the most common location for aneurysms along MCA. Figures legends: Fig. 1: Identification of MCA main bifurcation CTA images (A: sagittal, B: coronal C: axial D: 3D reconstruction) demonstrating an early cortical branch aneurysm (white arrow) arising at the origin of an early frontal branch (green arrow) proximal to the main MCA bifurcation (yellow arrow) which gives frontal (red arrow) and temporal (blue arrow) M2 trunks. The MCA main bifurcation (yellow arrow) is located at the genu. The accompanying diagrams (E, F G) display how to accurately identify the main MCA bifurcation from other branching points along MCA just by following the insular branches back towards their primary meeting at one point that is the MCA main bifurcation. We are used to start the check in sagittal views then to confirm by rechecking the axial and coronal CTA views. 3D reconstructions are sometimes needed. Fig. 2 CTA images (A: axial, B: coronal, C: sagittal the corresponding 3D reconstruction views (D, E F respectively) demonstrating an early cortical branch aneurysm (white arrows) arising at the origin of a large early frontal cortical branch (green arrow) just proximal to the right MCA genu. Such an aneurysm can be subjectively misclassified as an MCA bifurcation aneurysm especially in coronal views, but in sagittal and axial views, the frontal branch (green arrow) is seen running anteriorly and superiorly away from the insula. Also, the right MCA bifurcation (yellow arrow) is clearly seen distal to the genu giving frontal (red arrow) and temporal (blue arrow) insular trunks. Fig. 3 CTA images (A: axial, B: coronal, C: sagittal D: 3D reconstruction) demonstrating an aneurysm (white arrow) arising at the main MCA bifurcation (yellow arrow) which gives frontal (red arrow) and temporal (blue arrow) M2 trunks. Notice the frontal cortical branch (green arrow) arising from the frontal M2 trunk (red arrow). The MCA main bifurcation (yellow arrow) is located proximal to genu. Fig. 4 CTA images (A: axial, B: coronal C: sagittal) demonstrating an early cortical branch aneurysm (white arrow) arising at the origin of an early frontal branch (green arrow) proximal to the main MCA bifurcation (yellow arrow) which gives frontal (red arrow) and temporal (blue arrow) M2 trunks. The MCA main bifurcation (yellow arrow) is located proximal to genu. Fig. 5 CTA images (A: axial, B: coronal, C: sagittal D: 3D reconstruction) demonstrating an early cortical branch aneurysm (white arrow) arising at the origin of an early temporal branch (green arrow) proximal to the main MCA bifurcation (yellow arrow) which gives frontal (red arrow) and temporal (blue arrow) M2 trunks. The MCA main bifurcation (yellow arrow) is located at genu. Fig. 6 CTA images (A: axial, B: coronal C: sagittal) demonstrating a distal MCA aneurysm (white arrow) arising at the takeoff of a frontal cortical branch (green arrow) from the left frontal M2 trunk (red arrow) distal to the main MCA bifurcation (yellow arrow) which gives frontal (red arrow) and temporal (blue arrow) M2 trunks. The MCA main bifurcation (yellow arrow) is located proximal to genu.