22851 questions

How does the inflammatory response defend the host against pathogens?

The inflammatory response is a quick and non-specific immune response that takes place after the pathogen breaches the host's physical and chemical barriers (skin, mucus, lysozyme...). Pathogen-associated molecular patterns (PAMPs) are recognized as foreign by pattern recognition receptors (PRRs) on immune cells. This causes degranulation of mast cells, which release histamine. Histamine promotes vasodilation and increase in vascular permeability, allowing influx of more immune cells, such as neutrophils and macrophages, and complement proteins from the blood to the site of infection. Neutrophils and macrophages are phagocytes which engulf and destroy pathogens in a vacuole. Macrophages also release TNF-alpha, which acts like histamine to make capillaries more "leaky". These processes explain the four main symptoms of inflammation: heat, redness, swelling and pain.
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Ada E.

Answered by Ada, Biology A Level tutor with MyTutor

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For what values of k does the line y=kx-1 have two distinct points of intersection with the circle (x-2)^2+(y-3)^2=2?

sub y=kx-1 into circle equation, get (k^2+1)x^2-(8k+4)x+18=0for 2 distinct solutions need b^2-4ac>0, ie -8k^2+64k-56>0iff k^2-8k+7<0complete the square: intersections of equation in k satisfy(k-4)^2=9 so inequality satisfied when 1<k<7. strict inequality for distinct intersection
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Christopher B.

Answered by Christopher, who has applied to tutor Maths GCSE with MyTutor

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Prove by induction that the nth triangle number is given by n(n+1)/2

base case: (1 x 2)/2 = 1 as required inductive step: assuming statement holds for n=k, the (k+1)th triangle number is given by k(k+1)/2 + (k+1) by definition=(k^2+3k+2)/2=(k+1)(k+2)/2=(k+1)((k+1)+1)/2result follows by induction
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Christopher B.

Answered by Christopher, who has applied to tutor Maths A Level with MyTutor

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Discuss the possible benefits from horizontal integration of firms in a market where profit margins are falling

Horizontal integration is where a firm acquires or merges with another firm within the same industry and at the same stage of production. When a firm merges with another at the same stage of production, managerial economies of scale may be realised. This arises from the firm being in a better position to employ specialist managers which can then lead to increased productivity, thus reducing long-run average costs and therefore increasing the firm's profit margin. On the other hand, the firm may experience diseconomies of scale. This is where economies of scale cease to exist, and the law of diminishing returns comes in to play. The firm now sees an increase in its marginal cost. Bringing in new management can cause a conflict in ideologies which can lead to a slowdown in processes as managers are debating methodologies. As a result, long-run average costs may actually increase, which further reduces the firm's profit margin.
Horizontal integration can also boost sales resulting from an increase in the brand's recognition. Brand recognition would increase because the firms merge both their customer bases together, thus exposing the brand name to a wider audience. The increase in the brand's popularity would result in an increase in the consumer's trust in the brand and so sales increase, causing revenue to also increase. However, there are a number of costs associated with integration. During a merger, some form of restructuring must take place which will likely lead to a number of redundancies, which the firm will have to pay for. In some scenarios where one firm is taking over the brand of another firm, the dominant firm would have to pay the cost of re-branding all of the other firms branches. This can lead to a loss in the short term while an increase in profits is experienced in the long-term.
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Alessandro G.

Answered by Alessandro, who has applied to tutor Economics University with MyTutor

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“Is “Ethical” Consumerism A Solution To Poverty, Or A Dangerous Distraction?”

Argumentation is fundamental for a TSA essay - the purpose of the essay is NOT to give a balanced view of the argument demonstrating a sensibility to both sides, the purpose IS to create an argument that can convince the reader of your viewpoint and stance.
To that effect, the first step is to pick a side of the argument to fall down on - often it is better to pick a side less frequently argued and more conventionally controversial to demonstrate your unique ability to reason and argue. Also if it’s an argument that you don’t actually believe in, it will force you to follow the logic more rationally in order to make it as consistent as possible.
Example plan of argumentation:Introduction: frame the argument in a clear and precise way that gives you the freedom to expound - E.g. “Whether or not “ethical” consumerism, namely, the disregarding of consumption in accordance with the maximally efficient price (as determined by free market forces) in favour of consumption at artificially higher prices (as determined by socially-minded economic interventionists) rests on the definition of poverty undertaken in the argument. Poverty must be considered to refer to absolute levels of income and wealth not relative terms of inequality. To this end, “ethical” consumerism must be evaluated against whether or not it can alleviate the resource deprivation and economic isolation associated with absolute poverty, not whether it acts as a plausible method of progressive economic redistribution.”Argument 1 - the price mechanism is the most efficient way of allocating resources, any impediment on the price mechanism will create an inefficient and sub-optimal usage of resources. Argument 2 - “ethical” consumerism does nothing to address the causes of poverty; there is no focus towards education, healthcare, long-term economic development, or security that will alleviate the causes of poverty. Argument 3 - focusing the effort and financial capital wasted in a programme of “ethical” consumerism harms the consumer and, rather hypocritically, prices out of consumption those consumers with the least financial resources to begin with. As more goods were to see their prices rise with “ethical” consumerism as the driving force of price allocation, those economic agents we seek to assist out of poverty will only be further trapped by the higher pricing of “ethical” consumerism on an array of products. Optional Dismissed Counter-Argument 4 - whilst is can be argued that “ethical” consumerism can provide the means for incubating an industry that, in its conception, would have been eradicated from the comparative advantage other established competitors might have, and that those without the economic resources to consume “ethically” would not be forced to, this argument misses the point that any sub-optional misapplication of resources harms both consumers and producers on the margin of poverty first. Any inefficient allocation of resources has to be felt somewhere, and it is not with those with the means to consume “ethically”. Conclusion: take a firm stand and conclude concisely along the lines of your argumentation. It may be worthwhile saving a subtle new insight for the conclusion to provide the reader with a longer food for thought at the end - “E.g. “”Ethical” consumerism should, therefore, be considered in the same light as international emergency aid. An exogenous, financial injection designed to alleviate short-term economic suffering. If, however, “ethical” consumerism is to be considered as an authentic long-term solution to poverty, it’s price-mechanism distortion and efficiency incentivising corrosion will only deepen the causes of entrenched structural poverty, and fail to alleviate their symptoms. “Ethical” consumerism is nothing more than a well intentioned economic misdirect aimed at the symptom of poverty - regrettably, such a simple solution will do next to nothing to alleviate it’s cause.”
If you keep in the forefront of your mind that the TSA essay is a place to demonstrate your ability to argue through reason, with logic as the guiding force, you’ll write a sterling essay in ample time.
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Daniel W.

Answered by Daniel, TSA Oxford University tutor with MyTutor

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Expliquez la différence entre le COD et le COI

Le COD, ou complément d’objet directe désigne l’objet d’une action. Il n’est pas précédé par une préposition
Pour le trouver il faut répondre a la question : QUOI/QUI?
Ex: Emma mange une bananeEmma mange quoi ?>une bananeLe COD de cette phrase est donc une banane. 
Le COI désigne aussi l’objet de l’action, mais est introduit par une préposition Prépositions :  à/ de/ par/ vers/ jusqu’à après/avant/ vers/ depuis/ pendant/ pour sur/ sous/ entre/ devant/ derrière/ dans/ chez
Pour le trouver il faut répondre à la question : A QUI/ A QUOI?
Ex: Emma téléphone à son frèreEmma téléphone à qui ?> à son frère Le COI de cette phrase est donc à son frère 

Le COD et le COI sont normalement places après le verbe. Sauf si le COD ou le COI est un pronom. Alors il est place derrière. 
Ex: Emma l’attend (COD) Tom la mange (COD) Emma lui téléphone (COI) Tom y pense (COI)
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Tamara M.

Answered by Tamara, French GCSE tutor with MyTutor

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How should I write about work experience in my personal statement?

Work experience is an essential part of your personal statement however, people tend to list their placements rather than expressing what they have learnt and achieved. Remember: quality, not quantity. It's important to be selective. Choose no more than 3 placements and expand on them. For example, talk about how the various members of the multidisciplinary team were vital for a successful surgery and for the patient to make a comprehensive recovery. Also, mention the importance of skills, such as communication and collaboration, within the team. Then, demonstrate how and when you have used/developed these skills in extracurricular activities. Having a notebook at hand during your placements and writing down what skills you saw the doctors using can be very useful.
It's also a good idea to illustrate that medicine can be a demanding profession. For example, "interacting with terminally-ill patients at the hospital showed me the emotional stability that doctors require when witnessing the deterioration of patients". This shows the admissions tutor that you have a realistic understand of medicine as a profession. However, add emphasis to the fact that that the benefits outweigh the negative aspects

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Vaishali K.

Answered by Vaishali, Medical School Preparation Mentoring tutor with MyTutor

2 views

How should I write about work experience in my personal statement?

Work experience is an essential part of your personal statement however, people tend to list their placements rather than expressing what they have learnt and achieved. Remember: quality, not quantity. It's important to be selective. Choose no more than 3 placements and expand on them. For example, talk about how the various members of the multidisciplinary team were vital for a successful surgery and for the patient to make a comprehensive recovery. Also, mention the importance of skills, such as communication and collaboration, within the team. Then, demonstrate how and when you have used/developed these skills in extracurricular activities. Having a notebook at hand during your placements and writing down what skills you saw the doctors using can be very useful.
It's also a good idea to illustrate that medicine can be a demanding profession. For example, "interacting with terminally-ill patients at the hospital showed me the emotional stability that doctors require when witnessing the deterioration of patients". This shows the admissions tutor that you have a realistic understand of medicine as a profession. However, add emphasis to the fact that that the benefits outweigh the negative aspects

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Vaishali K.

Answered by Vaishali, Medical School Preparation Mentoring tutor with MyTutor

2 views
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