Recent comments in /f/askscience

[deleted] t1_j3wai1k wrote

Reply to Does the immune system have a limit on memory for vaccines? Can we vaccinate against any and all microorganisms if we wanted to? by AdiSoldier245

Not possible for example one set of famous genes called HLA are inherited genetically and passed on through different ethnic groups. Human diversity alone and laws of inheritance mean some groups are more susceptible to diseases than others. Additionally, while capable (in theory) of creating antibodies against any foreign microorganism it never is 100% fullproof. Remember that microorganisms are not helpless against the mammalian body, they are much more effective at dampening immune response.

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officialsamjordan t1_j3vmn2s wrote

Reply to Can autoimmune illnesses occur without autoantibodies? eg can neutrophils decide to become autoimmune? by lonelysuffering

Autoantibodies are like markers for autoimmune diseases, but can other things like white blood cells cause autoimmune diseases too?

From what I've learned, it turns out that autoimmune diseases can happen without autoantibodies. Some diseases are caused by other parts of the immune system like T cells, B cells and not just autoantibodies. And specifically about neutrophils, they are a type of white blood cells and play an important role in fighting infections but it's not clear if they are involved in autoimmune diseases.

It's all pretty confusing, but it seems like autoimmune diseases can have different underlying causes. So, it's possible that some autoimmune diseases can happen without autoantibodies.

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VT_Squire t1_j3v81lr wrote

Reply to comment by dnkushne in Will water ice melt faster if allowed to drain, or remain in the meltwater? by terjeboe

I'll put it to you this way by stealing an example straight from stack exchange.

Place a cocktail stick through an ice cube and lay it on top of a glass filled right to the top with (room temperature) water. The submerged half will melt quicker than that on top.

So what if we dial "room temp" down to 33 degrees? Same answer. What if we dial it up to 200 degrees? Same answer.

Air is an AWFUL medium for temperature to transfer. It'll take an hour to cool down a warm beer in the fridge. But it's like maybe 12 minutes submerged in water at the same temp as your fridge.

In a cooler you want the maximum of cold thermal mass but the minimum of heat transfer. THATS why draining a cooler makes the ice melt faster. You're literally allowing the ingress of warm air while actively displacing the cold thermal mass. It's got very little to do with wet vs dry like OP is getting at.

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dnkushne t1_j3v1px8 wrote

Reply to comment by VT_Squire in Will water ice melt faster if allowed to drain, or remain in the meltwater? by terjeboe

This is not right still. Both the air and water will primarily transfer heat by convection. Thermal conductivity is the measure of heat transfer within the same substance, not between two substances.

Assuming room temperature air (i belive this is the OPs intention) earlier comments are right about how the melt water will remain cold and thus have mich slower heat transfer from the ice to the water, thus slower melt.

Your missing that heat transfer is a function of the delta T (difference in temp between two susbtances) times a resistance value (convection primarily here)

Also belive this is confirmed by ice in cooler during camping. Ice and drinks stay colder if you don't drain the water.

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GiveItStickMan t1_j3uv1pl wrote

Reply to comment by bisnotyourarmy in Will water ice melt faster if allowed to drain, or remain in the meltwater? by terjeboe

I agree with this. Melting ice outside of a bath has 2 functions, drying the thin melted layer and thermal exchange from thermal layer. I thought of this like fins on a heatsink and the melted ice on the exterior as thermal paste.

Also this has variables and would need a test to determine but this was my initial thought also.

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