Sal

joined 3 years ago
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[–] Sal@mander.xyz 1 points 1 week ago

I have edited my original comment with important corrections. Commenting again so that you don't miss them.

[–] Sal@mander.xyz 2 points 1 week ago* (last edited 1 week ago)

EDIT: I looked more into the ethernet + RAK boards. I was surprised to find claims that the boards that make use of the Nordic nRF microcontroller do not expose an interface for receiving commands nor do they expose a Webserver. It seems they can push data to the MQTT broker, but it might not possible to control them over the network. Here is a short discussion I found about this: https://www.reddit.com/r/meshtastic/comments/1ebcnay/rak_board_ethernet_non_web_client_access

I can't find evidence to support that it works today. I know that ESP32-based meshtastic devices do expose the webserver and the TCP interface. But I am not sure about how to add the ethernet interface.

original commentSimplest option would probably be to make use of the RAK system. They provide modular boards for Meshtastic, and one of modules is an Ethernet interface: https://docs.rakwireless.com/product-categories/wisblock/rak13800/datasheet/

The WisMesh Ethernet MQTT gateway is an example of an assembled module that uses the RAK19007 WisBlock Baseboard as the base that includes the power management and the slots for attaching the modules, the RAK4631 LoRa transciever module to provide the radio, and the RAK13800 Ethernet Module to provide Ethernet connectivity.

The version that does not include an enclosure and has no Power-Over-Ethernet costs $43 through RAK. You can also get the versions with enclosure and with PoE. For PoE, you will need to have an ethernet modem/router capable of providing power over ethernet or a PoE ethernet switch.

I don't know much about the other Ethernet options, but there is a good chance that a good amount of them will consist of a custom 3D-printed enclosure with the RAK system inside.

Another option is to use a Raspberry Pi or a regular computer as a bridge. The computer/raspberry pi connects to the network over ethernet and interfaces with a standard Meshtastic device via USB or via a HAT using the PI's GPIO pins (example of the HAT: https://www.youtube.com/watch?v=91ULi9DWgds).

[–] Sal@mander.xyz 4 points 1 week ago* (last edited 1 week ago) (5 children)

I don't have the Heltec V3, but the model I was able to find online does support WiFi.

You need to connect to it using some other device. It can be with Bluetooth using an app, or via USB using a web client. Once you are connected to it, you can go to Radio Configuration and add the WiFi info in the Network settings.

Then, you need to figure out what its IP is. There are a few different ways to do it. Usually I log into my router and check the IP of the latest device to log into the WiFi.

You can then go to that IP via your browser, and you will see this:

You can then connect to it and interact with the device over the browser.

To interact with it using the python library, you set the device's IP as the NODE's interface. Here is an example of a very simple script that will connect to the node via its IP and cause it to automatically respond with 'Pong' to any message that it receives that contain 'Ping'.

import meshtastic
import meshtastic.tcp_interface
from pubsub import pub
import time

# Your Meshtastic node's IP
MESHTASTIC_NODE_IP = "192.168.8.149"

def onReceive(packet, interface):
    if 'decoded' in packet and 'payload' in packet['decoded']:
        try:
            message = packet['decoded']['payload'].decode('utf-8')
            sender = packet['from']
            if "Ping" in message:
                interface.sendText("Pong", destinationId=sender)
        except Exception as e:
            pass

interface = meshtastic.tcp_interface.TCPInterface(hostname=MESHTASTIC_NODE_IP)
pub.subscribe(onReceive, "meshtastic.receive")

while True:
    time.sleep(5)  # Keep the script running

[–] Sal@mander.xyz 4 points 1 week ago (8 children)

Is there a specific reason why you are choosing Bluetooth instead of WiFi? Connecting the Heltec V3 to the local WiFi will let you interact with it over the network. I think that this would make what you want to do a lot easier.

[–] Sal@mander.xyz 2 points 1 month ago

I would give the Letharia dye another try

Would love to... When I was in Oregon this lichen was super abundant. At the moment I am living in Amsterdam (Netherlands), and I see mostly Xanthoria, Evernia, Rhizocarpon, and a few other lichen species that grow on city trees, but they are very small and spotty, nothing compared to the wolf lichen in Oregon. I do miss the Oregon forests with the old growth sequoia redwood trees and all that lichen.

[–] Sal@mander.xyz 2 points 1 month ago (2 children)

9ft of snow?! I only experienced such deep snow in an urban setting while living in Connecticut for a year. I spent a few years in Oregon but the snow in the area never got so deep while I was there. When I was in the US I was not yet able to identify many fungi as I was mainly obsessed with animals (especially salamanders) back then, so unfortunately I did not really appreciate the diversity of fungi there. Although once in Oregon I did attempt to dye some socks using a wolf lichen (Letharia vulpina) and a pressure cooker. That did not end well.

[–] Sal@mander.xyz 3 points 1 month ago

I see. So it is not necessarily that their mycelium are better at surviving the freezing temperatures, but rather that either they fruit quicker once conditions are acceptable or that their fruiting bodies are more cold tolerant. Thanks, it's interesting.

[–] Sal@mander.xyz 3 points 1 month ago (6 children)

Cool! I just read their wiki page and it says

A snowbank fungus, it is most common at higher elevations after snowmelt in the spring.

Snowbank fungus is a new term for me. Not sure yet what makes a fungus thrive through snow. Maybe they have anti-freeze proteins?

Does your area get a lot of snow?

 

I'm still not sure of what the ant and plant species are.

[–] Sal@mander.xyz 4 points 1 month ago

In many cases the tweet is important because it was tweeted by a specific person. If only a screenshot is provided then one needs to go through the hassle of verifying it is a real tweet. A good approach would be to do both: post screenshot + link to neutral frontend

[–] Sal@mander.xyz 1 points 1 month ago (1 children)

Congrats!! Is your trip still ongoing, or you are done for now?

 

This article is from earlier in the year but I missed until now!

Abstract

The emergence of Batrachochytrium salamandrivorans (Bsal) poses an imminent threat to caudate biodiversity worldwide, particularly through anthropogenic-mediated means such as the pet trade. Bsal is a fungal panzootic that has yet to reach the Americas, Africa, and Australia, presenting a significant biosecurity risk to naïve amphibian populations lacking the innate immune defenses necessary for combating invasive pathogens. We explored the capability of near-infrared spectroscopy (NIRS) coupled with predictive modeling as a rapid, non-invasive Bsal screening tool in live caudates. Using eastern newts (Notopthalmus viridescens) as a model species, NIR spectra were collected in tandem with dermal swabs used for confirmatory qPCR analysis. We identified that spectral profiles differed significantly by physical location (chin, cloaca, tail, and foot) as well as by Bsal pathogen status (control vs. exposed individuals; p < 0.05). The support vector machine algorithm achieved a mean classification accuracy of 80% and a sensitivity of 92% for discriminating Bsal-control (-) from Bsal-exposed (+) individuals. This approach offers a promising method for identifying Bsal-compromised populations, potentially aiding in early detection and mitigation efforts alongside existing techniques.

[–] Sal@mander.xyz 1 points 1 month ago (1 children)

Alright! Some other tips:

  • Your current microscope is a 160 mm system, so make sure that the objectives are 160 mm and not infinity.
  • Make sure the objectives have an RMS thread
  • Once you move into higher-end objectives, you will have objectives that are specialized. For example, 'phase contrast' objectives have a dark ring inside of them. For the olympus brand their name often ends in 'PL'. These work with bright-field too. My 40/1.30 objective is actually a phase-contrast objective because I did not know this and ChatGPT told me it meant something different 😂 However, the objective does work well for me and I am now considering upgrading to a phase contrast-capable microscope (the BH2), so I made a good choice by accident.
 

A new species of salamander from Costa Rica, Bolitoglossa chirripoensis, has been described!

Two photos of the newly described salamander, Bolitoglossa chirripoensis

KLANK, JEREMY, et al. "A new species of salamander of the genus Bolitoglossa (Caudata: Plethodontidae) from the highest massif of the Cordillera de Talamanca, Costa Rica." Zootaxa 5642.5 (2025): 427-450.

Research Gate Link

 

cross-posted from: https://mander.xyz/post/31227704

This weekend I did some experiments with turmeric powder. Here are some images of the results, and the description of how to create these microscopic chemical landscapes is given below.

Turmeric powder is a fantastic material to play with. The powder has a high concentration of colored and fluorescent curcuminoids and volatile turmerone oils.

When you use a polar solvent to extract these compounds, what you get is a kind of fluorescent oily resin called a turmeric 'oleoresin'.

The curcuminoids are yellow at acidic and neutral pH, but they become bright red at high pH due to keto-enol tautomerization. There is a lot of cool things you can do with the curcuminoids in terms of photo/electrochemistry.

I have been playing with very simple chemistry under the microscope, and I have noticed that you can create some cool-looking micro-landscapes. During this process you can also see different types of physico-chemical processes happening in real time.

Procedure to do this:

  • Place a few grams of turmeric powder into a glass container
  • Add enough isopropanol to cover the material, and a bit more
  • Mix
  • Wait for the solids to settle
  • Collect a bit of the isopropanol liquid from the top and place on a glass coverslip
  • Wait for the isopropanol to evaporate.

At this time, you can see under the microscope that golden oil droplets have been deposited, and that the surroundings are also yellow. The drops are oleoresins, which consist of curcuminoids suspended in turmerones and other oily compounds. Thin curcuminoid films might also be forming in between these droplets.

  • Add a sprinkle of baking soda crystals (sodium bicarbonate) on top of the coverslip. You can blow on the coverslip if you accidentally add too much.

  • Add a small drop of water, and wait a bit.

At this time you can see that the crystals are dissolving under the microscope, but the colors are not changing. The water and oils are not mixing, and so you get this film of alkaline water surrounding the oil droplets, but nothing is yet really changing.

  • After waiting a few minutes, add a drop of isopropanol.

Now the isopropanol will re-dissolve the oleoresin and mix with the alkaline water. The carbonate ions are now able to react with the curcuminoids, and when they do, they go into the ketone form and instantly turn red. Under the microscope you can see quite dramatic movements of yellow and rad streaking as well as turbulent movements of the baking soda crystals.

  • Wait some time for the liquids to evaporate again

  • You will end up with a landscape that combines yellow resins, red resins, sodium bicarbonate crystals, and several different patterns.


You can vary the parameters - the amount of sodium bicarbonate, the position and size of the drops, you can pre-mix the water and isopropanol, etc. Small changes can drastically affect the resulting landscape.

16
Curcumin landscapes (infosec.pub)
submitted 2 months ago* (last edited 2 months ago) by Sal@mander.xyz to c/microscopy@mander.xyz
 

This weekend I did some experiments with turmeric powder. Here are some images of the results, and the description of how to create these microscopic chemical landscapes is given below.

Turmeric powder is a fantastic material to play with. The powder has a high concentration of colored and fluorescent curcuminoids and volatile turmerone oils.

When you use a polar solvent to extract these compounds, what you get is a kind of fluorescent oily resin called a turmeric 'oleoresin'.

The curcuminoids are yellow at acidic and neutral pH, but they become bright red at high pH due to keto-enol tautomerization. There is a lot of cool things you can do with the curcuminoids in terms of photo/electrochemistry.

I have been playing with very simple chemistry under the microscope, and I have noticed that you can create some cool-looking micro-landscapes. During this process you can also see different types of physico-chemical processes happening in real time.

Procedure to do this:

  • Place a few grams of turmeric powder into a glass container
  • Add enough isopropanol to cover the material, and a bit more
  • Mix
  • Wait for the solids to settle
  • Collect a bit of the isopropanol liquid from the top and place on a glass coverslip
  • Wait for the isopropanol to evaporate.

At this time, you can see under the microscope that golden oil droplets have been deposited, and that the surroundings are also yellow. The drops are oleoresins, which consist of curcuminoids suspended in turmerones and other oily compounds. Thin curcuminoid films might also be forming in between these droplets.

  • Add a sprinkle of baking soda crystals (sodium bicarbonate) on top of the coverslip. You can blow on the coverslip if you accidentally add too much.

  • Add a small drop of water, and wait a bit.

At this time you can see that the crystals are dissolving under the microscope, but the colors are not changing. The water and oils are not mixing, and so you get this film of alkaline water surrounding the oil droplets, but nothing is yet really changing.

  • After waiting a few minutes, add a drop of isopropanol.

Now the isopropanol will re-dissolve the oleoresin and mix with the alkaline water. The carbonate ions are now able to react with the curcuminoids, and when they do, they go into the ketone form and instantly turn red. Under the microscope you can see quite dramatic movements of yellow and rad streaking as well as turbulent movements of the baking soda crystals.

  • Wait some time for the liquids to evaporate again

  • You will end up with a landscape that combines yellow resins, red resins, sodium bicarbonate crystals, and several different patterns.


You can vary the parameters - the amount of sodium bicarbonate, the position and size of the drops, you can pre-mix the water and isopropanol, etc. Small changes can drastically affect the resulting landscape.

 

I just learned about hobby and read through some discussions about space weather in the spaceweatherlive forum.

It is not clear to me from those discussions where the data they discuss is coming from.

Are there tools that one can have at home to track space weather events? Through hobby-grade telescopes can one observe solar activity? Are diagnostic radio signals detectable with an SDR? Can an X-ray/gamma burst produce a strong enough diagnostic signal to detect with a radiation detector? Or are there some other type of detectors?

Is the main source of data used for interpreting solar activity patterns as a hobby the data that can be found here: https://www.spaceweatherlive.com/ ?

44
Focus-stacked image (infosec.pub)
submitted 2 months ago* (last edited 2 months ago) by Sal@mander.xyz to c/microscopy@mander.xyz
 

This is a stack of 7 images, you can click on the image to see the full resolution and guess what the subject is :D

The photos were taken using a Nikon D7500 camera connected through a T2 adapter tube with 2X magnification (NDPL-1(2X)). Microscope is the Swift SW380T. The objective is a 4x Plan objective.

For stacking the images together I use three tools: ImageMagick's mogrify to transform from the raw NEF files to .tif, Hugin's align_image_stack function to align the images, and enfuse to blend the images together.

The output .tif file was post-processed using rawtherapee in order to increase local contrast and tune some other parameters.

The process of focus stacking a set of images is rather simple in Linux. The programs above can be installed via the package manager. Then, you copy the raw files to focus-stack into a folder, and run the following sequence of commands:

(1) Convert from RAW to TIF:

mogrify -format tif *NEF

(2) Align images

align_image_stack -a aligned_ -v -m -g 10 -C *.tif

(3) Focus stack

enfuse -o result.tiff --exposure-weight=0 --saturation-weight=0 --contrast-weight=1 --hard-mask aligned_*

Below are the images used for the stack after alignment, for reference:

 

The linked video is about the open source 3D printable "Portable Upgradeable Modular and Affordable" (PUMA) microscope. The channel has several videos explaining fundamental concepts in microscopy and showing practical examples.

The github is here: https://github.com/TadPath/PUMA

The microscope can already perform many types of advanced techniques, and it is still being actively developed. The git states that the author is currently working on a motorized XYZ precision CNC stage. These precision stages are usually quite expensive, and they are very interesting because they enable some scanning microscopy techniques.

I am not associated with this in any way, I just watched a few videos and found them interesting enough to share.

45
Cyanobacteria (infosec.pub)
submitted 2 months ago* (last edited 2 months ago) by Sal@mander.xyz to c/microscopy@mander.xyz
 

This specimen came from a slimy film of algae that grew in one of my algal cultures. I think that it is a Nostoc. Objective is 40x/0.65

47
Plant stomata (infosec.pub)
submitted 2 months ago* (last edited 2 months ago) by Sal@mander.xyz to c/microscopy@mander.xyz
 

This image was taken through the 100x oil objective and a 2x camera adapter projecting the image into a Nikon D7500. The sample is a leaf from one of my plants (Dioscorea elephantipes, but I don't think this picture would look very different for other plant species)

The edges of he leaf were already yellowish brown. Here is a photo of that area with much less chlorophyll:

And here is a photo through the 40x objective using oblique illumination:

If you want to see some really fantastic photos of plant stomata I recommend having a look at Rolf Vossen's photographs here: https://microscopyofnature.com/stomata

I am looking through his documentation trying to understand how he managed to get those images. They are spectacular.

 

This is a photograph of a small trichome on the surface of a seedling through the 40x objective. Not sure if it is a happy trichome looking up at what it will become or a sad trichome looking down 😆 I liked the colors and the scene, reminds me of a painting.

Here is a photo through the 10x:

33
submitted 2 months ago* (last edited 2 months ago) by Sal@mander.xyz to c/microscopy@mander.xyz
 

I prepared a 1:200 dilution of red blood cells using a ~1% NaCl solution. The imaged region contains 4 nano liters of the diluted sample. This image was taken using a 40x objective.

A count is performed by counting the number of red blood cells in a few of these sections, averaging the result, and then converting back to red blood cells per microliter by multiplying times 200 (dilution) and dividing by 0.004 (sampled volume in micoliters).

For this particular sample I estimated 3.8 million red blood cells per micro liter of blood.

I tested a few different types of hemocytometer/Neubauer chambers from China and I can recommend this specific one:

There are some even cheaper alternatives but the lines are very difficult to see.

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