Diving - Science topic

“To be” is my answer—not merely as existence, but as conscious, purposeful becoming.

To be is to embrace the struggle, not in spite of its weight, but because it gives depth to meaning. It is nobler in the mind to suffer, yes—not out of resignation, but because suffering, when borne with awareness and dignity, transforms into wisdom. The storms of life, though fierce, shape the soul like waves shape the shore. “To be” means choosing presence over numbness, engagement over retreat, and meaning over nihilism.

“To not be” may promise silence and release—but it is an escape from the very fire that tempers courage, love, and purpose.

So, in the face of despair, contradiction, and absurdity, I choose to be—not because the path is easy, but because it is real, and within it lies the quiet heroism of continuing.

Dear Dr. Alex Thiangichu

Thank you for your response. I have contacted you via WhatsApp.

Dear Paul Cook,

I hope you're doing well. I wanted to follow up and see if you’ve had a chance to look at any of the materials I sent. To make it easier for you, I’ve included one article on sequential learning—a commentary on Hayhoe and Land (2001) titled:

"Eye-Tracking Gear Records Sequence Items but Not the Template Between Them: A Commentary on Hayhoe and Land (2001)"

The abstract is very short (only half a page) and precisely captures the scientific breakthrough and my line of thought on the matter.

Looking forward to hearing your insights.

Influencer marketing resonates strongly with learners and practitioners in most emerging markets, especially Nigeria, with rich, burgeoning growth in young talents at the nano, micro, or macro level. There is a need to set the rules to achieve cost-effective marketing spend

I think that these types of sports can be effective in preventing relapses after treatment for drug addicts. They want to open a new living space and significantly contribute to their sense of self. But, of course, this needs to be demonstrated with various studies.

Web 5.0 sounds fascinating! I’m intrigued by how AI, blockchain, and human-centered design can create a more personalized and secure digital experience. Looking forward to learning about its potential to transform our online interactions and build a more trusted internet.

Here is my take on 6G in video format:

6G: What, why, and how?

Dear Rahul Jain

A statistical model or a machine learning algorithm is said to have underfitting when a model is too simple to capture data complexities. It represents the inability of the model to learn the training data effectively result in poor performance both on the training and testing data. In simple terms, an underfit model’s are inaccurate, especially when applied to new, unseen examples. It mainly happens when we uses very simple model with overly simplified assumptions. To address underfitting problem of the model, we need to use more complex models, with enhanced feature representation, and less regularization.

Regards,

Shafagat

Assume you have different work-in-progress papers which you are developing in parallel. Some of them may be under review and you have to work on a revised version, other ones may be still in the data collection phase of the first submission. I wondered what would an average workload look like, based on your personal experience. Thanks.

Elias Mjaika Ndifon "could there be another reason?"

Space missions require a very high speed relative to earth. Air drag therefor is extremely dominant.

But there is one possibility to save energy. It could be feasible to transport a rocket with a giant plane nearly horizontally to a considerable elevation and begin there with the rocket operation.

@everyone @followers

Sports are a lot better.

The best solution for human eyes is mimicing their properties in monitors & screens.

Hi Naomi!

I don't know of any commercially available housing for such an application. However, the first idea that comes to my mind is using a short piece of galvanized tube (e.g. 3 inches wide), with threads on both ends, fitted with a cap on one end, and a drilled cap with an o-ring and a transparent acrylic sheet (~15-20mm) on the other (see image). Your camera could be then put inside, facing the acrylic window on one end.

Of course you would need some machine shop experience to do this, but I would argue that it can be constructed quite easily and also cheaply (probably less than 100 euros), while the tube would be strong enough for the pressures you are describing (~ 1000 dbar).

Materials:

Hope this will at least be a starting point.

Good luck with the project!

Greetings from UAegean,

Stamatis

Abolfazl Ghoodjani , more to the point, I think that the Assumption #5 you quote is bad advice.

Dear John,

Please, read my paper and see some options:

Regards,

Gokhan

Sustainable Tourism got to do with the local community. The economic impact of sustainable tourism in developing nations is still scarce in the field. Covid may have changed or affected the majority of local community socio-economy across the world particularly those heavily rely on tourism engagement to generate economy.

Challenges over the term 'Sustainable Tourism' itself. Nowadays with AI mushrooming - many fake destinations claim 'sustainable' while against the genuine value of 'sustainable' itself or time to go back revisit Ceballos- Lascurain Eco tourism origin long before sustainability exist in mass.

Post covid polemic - Is sustainability ever exist? the world is continuously suffering in the hand of mass-tourism (esp unethical China mass tourist) have ongoing discussion yet heavily over webinar platforms. Or does covid itself fails to provide a steadfast lesson to an unethical tourist?

I am no expert in penguins. However, heart rate is directly correlated to gas exchange. When they slow their heart-rate - their body uses less oxygen/per minute, meaning they can survive on their gas reserve (in the lungs) for much longer. This, in turn, lowers the amount of CO2 build-up (toxic) in the body.

It seems to me it may be a method for them to stay underwater for longer periods!

I strongly suggest uploading your observations to inaturalist.org for identification which in that way you might get immediate identification by AI or other users.

It's a question of sampling with multiple frequencies: data acquired at 19.2 MHz (input) and displayed at 25MHz (output).

It seems you can't change your output frequency, 25 million samples per second.

Then you need to feed these 25 million samples from what you get: 19 200 000 samples (values) per second.

This is a known issue in signal processing called oversampling.

Call 19.2 MHz f1 and 25 MHz f2.

The theory is that you want a f3 which is divided by each f1 and f2 (f3=n*f1, f3=m*f2). This is elementary algebra, you want f3 smallest common multiple of f1 and f2 (easy, compute it).

Then what you do is an expansion:

-build n times more samples from your acquired signal than what you acquired.

This is called interpolation, extrapolation.

Upsampling by factor n)

-from the new set you want to select m times less (on average you want one sample from any m new samples)

Beware of Nyquist rule: low-pass filter before downsampling by a factor m.

You can find the details of these steps in any Signal Processing textbook.

Does it help you?

I kept both species - I might be unfair but i always liked the Wonderpuss more ;-) i will share some pictures of the two species in the lab - give me a day or two

This looks indeed like a Laccophilus sp. This cosmopolitan genus is known to be represented also in Bangladesh. Hájek & Šťastný (2005) mention L. chinensis and L. punctatissimus from there, for example. Difficult to be sure about the species from the photo.

I do not understand the specific groups involved, but I am guessing, from what I see, that you intend some contrast between groups with the five lung volumes as "dependent" variables. In that case, unless you have some interest in considering a superordinate construct composed of a weighting of the five variables, but rather are interested in the between groups effect of each of the five variables, I would not use MANOVA regardless of the intercorrelations of these five variables. MANOVA would be simply addressing a question that is not yours. You should accomplish some sort of per-hypothesis alpha correction in respect to testing five hypotheses. There are options here, but the most important thing is to note the "probability pyramiding" issue and take appropriate steps. Carl Huberty and I treated all of this in some detail. If you want to take a look, I have the full-text here on RG.

Here's a successful example from the UK

Hi Juan,

As Ali Kalantarifard mentioned might need a bit more info to help.

One thing to be careful of is that hexadecane can swell PDMS and can potentially cause leaking (atleast from my experience). As Ali said don't think the viscosity is an issue, people commonly use much more viscous oils (e.g. mineral oil).

If your device material is not naturally hydrophobic you will need to do surface treatment. For PDMS devices our lab typically uses aquapel for fluorocarbon based oils, and RainX to treat for hydrocarbon oils, mineral oil, etc.

I've reviewed the two MIT thesis documents. They are in line with my understanding of the current technology. A question that needs to be addressed is why risk (and spend money) on a person instead of ROVs. If the need is there, then the R&D costs can be weighed.

ROV BASED IMAGE ANALYSER

Hi Tom,

Hi Tom,

Here are papers that could be relevant for you:

https://www.nature.com/articles/s41598-017-06505-4

best wishes,

Bert

I also clarify my question further: will deep-sea-diving induce rise in right cardiac atrial pressure ALONE? Or raise the pressure of both cardiac atria? Will deep-sea- diving generate a right-to-left shunt shunt at the level of the cardiac atria?

I agree with Dr. Gruntmeir. I've seen this and others tick teratology before that can occur due to excessive inbreeding within an old tick colony. Introduce new wild specimens in your tick colony.

No

There is Oxygen depletion sachets that you can place in a sealed chamber along with your plates that you cultured. The Sachet reacts with all the oxygen and depletes it, therefore creating an anaerobic environment for your bacteria to grow.

Good subject

Yes

No tengo experiencia en el uso de dichos software. Lamento no poder colaborar con ustedes

Thank you very much!

Birhanu , a good point, you have tossed up. Measuring long term sustainability could be visible in the backdrop production of a cropping system over space and time , further evident through improvement in livelihood options. After all, this is what we have to resort to climate resilient agriculture. If production of a cropping sequence is dwindling over space and time , it's conveniently assumed agriculture is climate change vulnerable...And we are more concerned with crop response than how much carbon dioxide associated or other GHG emissions related issues are cropping up..how is agriculture affected , we are more concerned as an agriculturist..there could be many more issues ..no doubt..

1) Not exactly an internal wave, but the two-directional current system in the Bosphorus has been known for centuries.  Surface waters flow from the Black Sea to the Sea of Marmara, and bottom (much more saline) waters flow from the Marmara to the Black Sea at the same time.  Fishermen wanting a "free ride" to the Black Sea against the surface current would lower their nets to catch the lower flow.

2)  Fridjtof Nansen had a research ship named the "Fram", which may be the one that Dennis Mazur is referring to above.

This can be simply explained by understanding gas laws and the increase of pressure due to the weight/density of water around the bottle. Everything else has to do with the static stability of the bottle.

Regarding lungs: As long as there is no pressured air/gas put to your lungs and then a decrease in surrounding pressure happens (e.g. by ascending), there is no severe danger to lungs. Furthermore, in the literature towards Apnoe you will find lots of information regarding physiological processes such as "Blood Shift".

Gas laws important in this context encompass the ideal gas equation (Boyle-Mariott/Gay-Lussac/Chales), the partial pressure concept as expressed in Dalton's Law, and the Law of Henry (which denotes the ability of gas solution in liquids under high-pressured conditions....

But basically... this question can be best answered, if you take one of the basic diving course theory books or do an open-water-diving course ;)

As water does transport electricity quite good, it is highly doubtable that the use of any electricity devices for electroshocks will work in the way we are used to in air surroundings. There might be three different anwers... (a) highly targeted electroshocks to the surface, of e.g. a shark might work if the device is designed for underwater circumstances; (b) there is not really any effect as the electricity is distributed through the water and disperted; (c) in certain circumstances it might get dangerours (compare lightning to water)...

There are a great many options with surface supplied diving.  Typically hookah is for shallower water whereas more commercial systems can be used deeper.  Each system should have clear specifications as to capabilities and required maintenance. 

One of the main considerations are the conditions the diver is exposed to; will they get to cold?  Surface supply may give you virtually unlimited air supply but dive time and depth limits still apply to the diver.

Hookah can be convenient and versatile.  One is shedding the weight of the tanks but adding a tether that can get tangled.

Since altitude DCS can be either rapid or slow, it depends on the scenario. In a rapid decompression, many of the effects can happen very quickly such as hypoxia, cyanosis, ear/intestinal discomfort. Diving is most associated with things like the bends which are not as common in rapid decompression. If you mean long term exposure at high altitude such as among climbers, the effects may be more progressive. Altitude sickness may result in fluid in the lungs.

First of all, epileptics fail fitness for diving in most cases including freediving or apnea diving. Only when for long time free of seizures without anticonvulsants, normal EEG and without cerebral MRT-lesions, fitness for diving can be achieved.

Secondly, regardless of CO2-content, apnea/breathhold diving can lead to hypoxia what can be followed by sudden acute symptomatic loss of consciousness and motor controll also known as "Samba", which is self-limited in length.

For this kind of hypoxia, two mechanisms are responsible:

a) In deep diving, returning to surface is alsways associated with reduction of environmental pressure, what is followed by a reduction of oxygen-partial pressure in the lungs, what leads to redistribution of oxygen from bloodstream to alveoli and cerebral hypoxia - ascent black out.

b) In pool diving for distance, hyperventilation is performed for postponing inspiratory reflexes. If stimulus to breathe in again comes too late, hypoxia ocurrs and leads to sudden shallow water black out.

Hi Phillip,

You should check your dive profiles: 3 x 30 m dives every day for 2 weeks generate high probability for DCI. Fatigue is one of DCI clinical symptoms...

Good luck and be careful.

Enjoy:

Hello Daniel,

I have been directing the strength and conditioning of the USA Diving Olympic and National teams for about the past 10 years so I think I can add some information to what has already been said. It would take pages and pages to respond thoroughly, but I will give you some things to think on.

I organize 'trunk' training ('core' using your terminology) according to movement specificity for diving. The primary trunk movements in diving can be organized into 4 categories:

1). trunk moving on legs - as in sitting up type exercises

2). legs moving on trunk - as in hanging pike ups

3). trunk and legs flexion/extension - as in a 'v-up' exercise

4). long-axis twisting - as in 'log rolls' and variations

Then I use these categories to ensure that at every workout at least one exercise from each category is included, and then add more sets to weaker areas for specific athletes. In addition to movement specificity, force/velocity characteristics and general training principles need to be considered. For example, during some times of the annual plan divers will do standing weighted somersaults (wt vests - not ankle wts). Sometimes of the year the emphasis is on higher resistance trunk training (exercises are weighted and tempo is slower), and other times the same exercises might be used but with a focus on speed of execution and excellent form and control. For elite/Olympic divers I use a rule of thumb of about 400+ repetitions of 'trunk' exercises each day, every day of the training week (depending on the specific athlete, time of the year, which year of the quadrennium, etc). Having worked with a bazillion strength coaches over the years, this is one area where they generally lack a good 'eye' for specificity since most don't have personal experience with acrobatic type movements. If you follow the 4 categories from above, and come up with exercises that fit each category, you will already be way ahead of the game.

I hope you found this information useful. If you will be at the USAS National Convention in Anaheim next month, I will be presenting on S&C for junior divers in the coaches' sessions.

Best wishes,

Jeni McNeal, PhD

Eastern Washington University

USAD Lead Strength and Conditioning consult