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NNadir

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Current location: New Jersey
Member since: 2002
Number of posts: 27,286

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Coronavirus Thanks Ron DeSantis for Making It Feel So Welcome at Spring Break

MIAMI BEACH (The Borowitz Report)—In an exuberant endorsement of a 2024 Republican Presidential hopeful, the coronavirus thanked Florida’s governor, Ron DeSantis, for “making me feel so welcome at spring break.”

“It’s been a tough couple of months for me, since Biden came in and started boosting vaccinations and mask-wearing,” the virus said. “I really needed this vacation.”

The coronavirus’s praise of DeSantis as “a fantastic host” stood in sharp contrast to its harsh criticism of the Miami Beach mayor, Dan Gelber, whom the pathogen called “a total buzzkill.”

“Dan Gelber has not made me feel welcome at all, which I find divisive and hurtful,” it said.

The coronavirus also predicted that it would not be alone in supporting DeSantis’s expected White House bid. “Every variant I talk to is excited about it,” the virus indicated.


Coronavirus Thanks Ron DeSantis for Making It Feel So Welcome at Spring Break

I want to live in a world where I can be a physicist without also being asked to speak on...racism.

A Black Physicist Is Borne Back Ceaselessly Into the Past

It's open sourced, but some excerpts:

I remember the moment my freshman year of college when I asked my electromagnetism teaching fellow what a breadboard was and instead of answering my question, he laughed and said, “You should know this. You don’t belong in this class.”

The course was an introduction to physics for physics concentrators (Harvardspeak for “majors”). For me, I thought. But I was supposed to know how to read a circuit diagram and how to use a breadboard to build the circuit in the drawing. Of course, I had been looking through my lab kit for something with a label on it. I had not been expecting that I was supposed to just know that the slab of plastic with a bunch of holes in it was a breadboard.

This incident became part of a growing file of stories about being told I didn’t belong, along with the numerous times fellow students told me I didn’t “look like a physics concentrator.” When I complained to peers about being on the receiving end of these comments, they would then insist it was because I dressed more nicely than they expected science concentrators to dress. But my clothing was less nice than everyone else’s, and I often showed up to breakfast in my pajamas, trying to live my best version of a real-life scene in Real Genius (a favorite film about physics students). My friends and study partners refused to acknowledge the obvious: a Black woman—even a light-skinned one—violated everything we had been taught about who belonged in physics.

During winter break that year, I called my mother and said I was switching to anthropology. Another Black student had just dropped physics and switched to another concentration on the advice of their physics adviser, who suggested they would be “better suited” for it. This conversation still regularly replays in my head: my mother’s guilt-tripping insistence that she hadn’t worked a job as a night secretary, allowing me to stay jobless and enrolled in my nice magnet high school—which required a three-hour commute on the school bus—just so I could quit physics...

I am not clicking on any news item about the shooter.

I'm going with Jacinda Ardern's prescription for mass murderers. They seek attention and to the extent we deny it, we defeat them.

For me at least this murderer is a non- person.

There's a first time for everything...

I don't check the values at the Mauna Loa Carbon Dioxide Observatory every day, although I do check it weekly.

Often, but not regularly, I check the Recent Daily Average Mauna Loa CO2 in anticipation of what the weekly average data might look like the following Sunday.

Today, accessed on 3/21/21 at 6:10 pm EDT, it looked like this:

March 20: 418.46 ppm
March 19: 418.22 ppm
March 18: 418.18 ppm
March 17: 417.25 ppm
March 16: 417.31 ppm

More interesting are the hourly figures for 3/21/21, which are shown graphically:



Like I say, I don't look at this particular graph every day, but this is the first time - there is a first time for everything - that I've seen hourly readings over 420 ppm. (We will surely see weekly averages over this value by May, setting new records for the highest values for the concentration of the dangerous fossil fuel waste carbon dioxide ever recorded at the Mauna Loa observatory, but this is the first time - there may have been others recently - I've seen hourly readings that high.)

Speaking of first times, the first time that I heard that so called "renewable energy" would save the world, was when I read the famous "genius" article by the anti-nuke Amory Lovins in October 1976: Energy Strategy, the Road Last Traveled. (In 1980, he predicted that if we didn't abandon nuclear power, there would be nuclear war. Nuclear Power and Nuclear Bombs.)

I haven't experienced any nuclear wars since then, but perhaps I missed something. Let me know if you're aware of one. All the wars I've seen have been wars conducted by converting oil into weapons of mass destruction, and many have been fought to procure oil.

In October of 1976, the monthly mean concentration of the dangerous fossil fuel waste carbon dioxide in the planetary atmosphere was 328.72 ppm.

What's 90 ppm between friends?

I, um, never had much use for Amory Lovins ideas about solar heated molten salt tanks in every suburban backyard, but I will say that I agree with him about the value of energy efficiency, but for quite a different reason.

For him, it's about assholes living "efficiently" in McMansions in Snowmass, CO among the glitterati, with ever more oblivious oracular pronouncements drooling out of their mouthes.

For me, since I understand Jevon's Paradox better than a poorly educated self declared "physicist," energy efficiency is about extending energy to those who lack it, since I regard access to energy as a basic human right.

To each his own, I guess.

I don't know when I first heard that wind turbines would save the world, but it was around that time I heard - and actually believed - that solar cells would save the world. I'm sure that I began hearing about - and believing in - the wind energy scam by the early 1980's.

We used to say, "experiment trumps theory," but the the word "trump" has become an obscenity, so let me suggest that "experiment overrules theory."

If the experiment gives a result different than what the theory predicts, it's not the experiment that should be thrown out, but rather the theory.

After 50 years of cheering and chanting, the theory that so called "renewable energy" would save the world has been experimentally found to be in error.

That's a fact.

Facts matter.

Have a nice evening.


Fields of Gold



Best version ever. One of the saddest stories in music.

While our nation focuses on yet another murderer,...

I admire Jacinda Ardern more and more.

She struck exactly the right tone, dressing in traditional Muslim attire, visiting with the victims, and refusing to acknowledge the murderer by refusing even to say his name.

Dopamine-based mechanism for transient forgetting

The paper I'm going to discuss in this post is...um...wait...I forget...oh yeah, this one: Sabandal, J.M., Berry, J.A. & Davis, R.L. Dopamine-based mechanism for transient forgetting. Nature 591, 426–430 (2021)

An excerpt from the introductory text:

Memory formation, consolidation and retrieval are well-known functions that support memory expression; however, the processes that limit these functions—including forgetting—are less understood. Forgetting has been characterized as either passive or active, and is crucial for memory removal, flexibility and updating1,2,3. Memory may be removed completely, resulting in permanent forgetting; or temporarily irretrievable, resulting in transient forgetting.

One form of active forgetting—known as intrinsic forgetting—involves one dopamine neuron (DAN) that innervates the γ2α′1 compartment of the axons of mushroom body neurons (MBNs) and the dendrites of the downstream, compartment-specific mushroom-body output neurons (MBONs)4,5,6. This DAN resides in a cluster of 12 DANs in each brain hemisphere that is known as the protocerebral posterior lateral 1 (PPL1) cluster4. Current evidence indicates that the ongoing activity of these DANs after aversive olfactory conditioning slowly and chronically erodes labile and nonconsolidated behavioural memory5, as well as a corresponding cellular memory trace that forms in the MBONs6. This intrinsic forgetting mechanism is shaped by external sensory stimulation and sleep or rest7, and is mediated by a signalling cascade in the MBNs that is initiated by the activation of the dopamine receptor DAMB, which leads to the downstream activation of the actin-binding protein Cofilin and the postulated reorganization of the synaptic cytoskeleton1,8,9.

By contrast, there is little understanding of the mechanisms that arbitrate transient forgetting. Neuropsychological studies of failures or delays in retrieval in humans have primarily focused on lexical access. Phonological blockers or interfering stimuli produce a tip-of-the-tongue state10—the failure to recall the appropriate word or phrase. Tip-of-the-tongue states are resolved when the distracting signals dissipate10. Several brain regions have been implicated in tip-of-the-tongue states from functional magnetic resonance imaging studies11, but the neurobiological mechanisms that produce a temporary state of impaired retrieval are unknown. Our study offers an entry point into this area of brain function...


I'm not saying that we should forget about this paper, but animal model discussed is flies:

Wild-type flies that were subjected to aversive olfactory conditioning (an odour coupled with an electric shock) using several, spaced training cycles displayed robust long-term memory (LTM) by 72 h after training (Fig. 1a, b). To determine how exposure to an interfering stimulus might affect expression of LTM, flies were briefly stimulated with airflow, electric shock or blue light before the memory retrieval test. Memory expression was weakened with increasing stimulus strength after experiencing these distractors (Extended Data Fig. 1a–c). These effects were observed only on cycloheximide-sensitive memory (Fig. 1b, c). As cycloheximide blocks protein-synthesis-dependent LTM (PSD-LTM), the difference in performance index between untreated and cycloheximide-treated flies represents the magnitude of PSD-LTM. The expression of PSD-LTM resurfaced at significant levels by 1 h after presentation of airflow, shock or blue light (Fig. 1b, c, Supplementary Information), which indicates that the memory impairments were temporary and produced by transient forgetting.


I personally had no idea that flies could be trained with blue light. One learns something every day, and then one dies.

Some figures from the text:

Fig. 1: External stimuli transiently disrupt retrieval of PSD-LTM.



The caption:

a, Aversive olfactory conditioning paradigm used to generate PSD-LTM. b–d, Cycloheximide (CXM)-treated wild-type (Canton-S) flies were exposed to interfering stimuli: airflow (b), electric shock (c) or blue light (d), and tested for 72-h or 73-h memory. Box-and-whisker plots show the range of individual data points, with the interquartile spread as the box and the median as the line bisecting each box. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001; n = 12 (b–d), two-way analysis of variance (ANOVA) with Tukey’s test. Exact P values and comparisons are given in Supplementary Information.


Some more text ("DAN" is described above in the introduction, as dopamine neurons, as are PPL1 protocerebral posterior lateral 1 1:

Transient forgetting through dopamine

Because DANs of the PPL1 cluster (PPL1 DANs) are involved in intrinsic forgetting, we asked whether they might also be involved in the processes that underlie transient forgetting. Pilot experiments demonstrated that strong, prolonged thermogenetic stimulation of all 12 PPL1 DANs per hemisphere (TH-D′>TrpA1 flies; for a full list of fly lines with their genotypes, see Supplementary Information) significantly reduced expression of PSD-LTM (Extended Data Fig. 2a–c) even 24 h before retrieval. We observed the opposite effect upon blocking synaptic output from PPL1 DANs (TH-D′>Shibire), which suggested the existence of a memory reserve that remains hidden unless synaptic output from the DAN is suppressed (Extended Data Fig. 2c). We used these assays and a collection of split-gal4 fly lines to spatially restrict TrpA1 expression to subpopulations of the PPL1 DANs


As far as I'm aware, no protocerebral Republicans were injured in this study, only flies.

Some of the flies, had a mutant DAMB (dopamine receptor in mushroom bodies) - no mushroom fly on fecal mass related jokes are acceptable in the Science forum - and the mutants, as mutants do, behaved differently.

Fig. 2: Transient suppression of memory engages a single pair of PPL1 DANs and the dopamine receptor DAMB.



The caption:

a, Schematic depicting the right hemisphere of a fly brain. One DAN (dark grey circle) in the PPL1 cluster synapses onto the MBN α2α′2 compartment (dark grey). Brief stimulation of PPL1-α2α′2 (058B>TrpA1) immediately before retrieval transiently suppressed, whereas blocking synaptic output (058B>Shibire) temporarily enhanced, expression of PSD-LTM. b, Conditioned flies were fed with RU486 to induce RNAi expression in the MBN. Knocking down DAMB, but not dDA1, blocked the PPL1-α2α′2-induced suppression of memory. PPL1-α2α′2-lexA, MB-GeneSwitch>uas-RNAi, lexAop-TrpA1 flies. Box-and-whisker plots show the range of individual data points, with the interquartile spread as the box and the median as the line bisecting each box. *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001; n = 12, two-way ANOVA with Tukey’s test. Exact P values and comparisons are shown in Supplementary Information.


In elegant work, the authors focused on a particular neuron in the fly and imaged. (Don't try this at home, but do, if you pray, pray for the graduate students who imaged fly neurons.)

Next figure:

Fig. 3: Stimulating PPL1-α2α′2 did not erase the 72-h PSD-LTM trace in MBON-α2sc.



The caption:

a, Flies were subjected to spaced training using OCT (O) as the CS+ and BEN (B) as the CS−. MBON-α2sc dendrites were imaged with or without a 6-h TrpA1 stimulation of PPL1-α2α′2 (R82C10-gal4). b, Group differential traces and quantification of the odour responses to OCT (CS+) and BEN (CS− ) in flies kept at 23 °C or treated at 30 °C between 42 and 48 h. Left, middle, activity as a function of time with odour stimulation. Right, average response magnitude within the first 5 s of odour onset (odour delivery duration). Calculations are provided in the Methods. The differential reflects the difference in odour response between CS+ and CS−. No PPL1-α2α′2: R34B02-lexA>lexAop-GCaMP6f, uas-TrpA1 flies. With PPL1-α2α′2: R82C10-gal4, R34B02-lexA>uas-TrpA1, lexAop-GCaMP6f flies. Ectopic activation of PPL1-α2α′2 did not alter the training-induced calcium transient differential. c, MBON-α2sc dendrites in the flies with PPL1-α2α′2 were imaged before (pre) and after (post) a 5-min TrpA1 stimulation. Brief stimulation of PPL1-α2α′2 did not change the training-induced calcium transient differential. Box-and-whisker plots show the range of individual data points, with the interquartile spread as the box and the median as the line bisecting each box. P > 0.05; n = 12 (b), n = 4 (c, no TrpA1 stimulation), n = 7 (c, TrpA1 stimulation), two-way ANOVA with Tukey’s test. Exact P values and comparisons are shown in Supplementary Information.


The DAMB protein expression was knocked down by using the abortifacient drug RU-486, which apparently results in the generation of interfering RNA, RNAi. (RNA is in the news these days, for good and for bad.)

There's a line in the wonderful movie Elizabeth where the character played magnificently by Geoffrey Rush remarks to the character played by Christopher Eccleston, the Duke of Norfolk, who at the moment that he is to become executed for his Catholicism, he remarks, "The people will remember me," whereupon the Rush character, Walsingham, says "No the people will forget."

Here, the flies will forget.

Fig. 4: Airflow, electric shock or blue light require PPL1-α2α′2 and DAMB function to cause transient forgetting.



a, Blocking synaptic release from PPL1-α2α′2 and normalizing LTM expression by differential spaced conditioning. Flies were exposed to airflow (Fig. 1b) or blue light (Fig. 1d), but at 30 °C (for 20 min) to concurrently block PPL1-α2α′2 output. Stimuli exposure and heat treatment terminated 5 min before a memory retrieval test at 23 °C. Inhibiting synaptic release from PPL1-α2α′2 blocked the transient forgetting induced by airflow (left) or blue light (right). b, Flies were trained with different number of spaced sessions at 18 °C and shifted to 30 °C for 2 d, 24 h after training to induce DAMBRNAi in the α/β MBN (c739-gal4, gal80ts>uas-RNAi, uas-dicer2 flies). Flies were then exposed to airflow, electric shock or blue light immediately before retrieval. DAMB knockdown fully blocked the transient forgetting from exposure to external stimuli. c, Working model for transient forgetting. The expanded version contrasting permanent and transient forgetting is shown in Extended Data Fig. 7. Box-and-whisker plots show the range of individual data points, with the interquartile spread as the box and the median as the line bisecting each box. *P < 0.05, **P < 0.01, ***P < 0.001, **** P < 0.0001; n = 12 (a, b), two-way ANOVA with Tukey’s test. Exact P values and comparisons are shown in Supplementary Information.


The paper's conclusion:

We found no robust decrement in expression of PSD-LTM after PPL1-γ2α′1 stimulation (Extended Data Fig. 2), which points to the existence of two separate dopamine-based circuits for permanent and transient forgetting. This functional separation may indicate a fundamental principle in the organization of circuits that mediate several forms of forgetting.

However, the DAMB receptor is used for both permanent and transient forgetting. DAMB is widely expressed across the MBN axons12 but alters synaptic plasticity differently across MBN compartments29. It is possible that DAMB signalling may be distinct for the two forms of forgetting. DAMB preferentially couples with Gq, the knockdown of which inhibits the potent erasure of memory13, but its potential role in transient forgetting is unknown. The scaffolding protein Scribble orchestrates the activities of Rac1, Pak3 and Cofilin8, all of which are important for the permanent forgetting pathway (Extended Data Fig. 7). However, Scribble knockdown or inhibition of Rac1 does not enhance the PSD-LTM8,9 as is the case in DAMB-knockdown flies, which suggests that this scaffolding signalosome does not have a large role in transient forgetting. In summary, the two distinct forms of forgetting—transient and permanent—share a dopaminergic mechanism and a common dopamine receptor, but differ in upstream and downstream neural circuits and in downstream signalling pathways within MBNs.


OK, I'll say it. I'm drawn to papers focusing on obscure stuff like this like a fly on shit.

Have a nice evening.

On now: A conversation with Bill Clinton, on the future of Democracy.

https://ecornell.cornell.edu/keynotes/view/K031821b/

Angel

The greenhouse gas emissions of indoor cannabis production in the United States

The paper I'll discuss in this post is this one: The greenhouse gas emissions of indoor cannabis production in the United States (Summers, H.M., Sproul, E. & Quinn, J.C. Nat Sustain (2021))

The abstract of the paper, which should be open sourced, says it all:

The resulting life cycle GHG emissions range, based on location, from 2,283 to 5,184 kg CO2-equivalent per kg of dried flower. The life cycle GHG emissions are largely attributed to electricity production and natural gas consumption from indoor environmental controls, high-intensity grow lights and the supply of carbon dioxide for accelerated plant growth.


Some excerpts from the full text:

Understanding the greenhouse gas (GHG) emissions of commercial cannabis production is essential for consumers, the general public and policy makers to improve decision making to mitigate the effects of climate change. Since recreational legalization was pioneered in Colorado in 2012, the US legal cannabis industry has rapidly grown from a US$3.5 billion industry to US$13.6 billion in annual sales, with states like Colorado selling more than 530 tonnes of legally grown cannabis product every year1,2. Additionally, with 48% of adults in the United States having tried cannabis at some point in their life and 13% of adults having consumed in the last year, substantial demand exists at the consumer level3. Despite its rapid growth and widespread use, there is minimal quantitative understanding of the GHG emissions from legal indoor cannabis cultivation.

The initial amendment legalizing recreational cannabis in Colorado required the majority of cannabis product to be sold at a collocated retail location4. This restriction led to cultivation practices occurring within the city limits of Denver, CO. This, along with security, theft and quality concerns, consequently led to the cultivation of cannabis indoors. Although data concerning the exact amount of cannabis by cultivation method are not currently publicly available for the United States, a recent survey of producers in North America showed that 41% of respondents indicated that their grow operations occur solely indoors5. It is well known that indoor cannabis cultivation requires significant energy input, reflected in high utility bills and industry reports4,6,7,8,9. However, many of these large energy loads, along with other material inputs required to cultivate indoor cannabis, have not yet been equated to GHG emissions.

Previously, rudimentary quantifications of GHG emissions from indoor cannabis have been performed by equating emissions with electricity use from monthly bills6,7. However, this approach omits additional GHG emissions from other energy sources, such as natural gas, upstream GHG emissions from the production and use of material inputs, and downstream GHG emissions from the handling of waste. The most thorough report quantifying GHG emissions from indoor cannabis is from Mills10, which states that growing 1 kg of cannabis indoors releases 4,600 kg of carbon dioxide equivalent (CO2e). However, the scope of the work was intended to be a central estimate, representing a singular US location case study for the industry’s general practices. Furthermore, Mills10 conducted this study prior to legalization and only used data from small-scale experimental systems, thus lacking validation of full-scale commercial grow operations...

...An indoor cannabis cultivation model was developed to track the necessary energy and materials required to grow cannabis year-round in an indoor, warehouse-like environment. This environment maintains climate conditions as required for the cannabis plants, yielding a consistent product regardless of weather conditions. The model calculates the necessary energy to maintain these indoor climate conditions by using a year’s worth of hourly weather data from more than 1,000 locations in the United States11. The analysed locations are independent of current legal status and represent hypothetical grow facilities in all 50 US states. The model then converts the required energy, supplied from electricity and natural gas, into GHG emissions through electrical grid emissions data from 26 regions in the United States12 and life cycle inventory (LCI) data13,14...


Here's a look some pictures from the paper:

Fig. 1: Life cycle GHG emissions and energy intensities from indoor cannabis cultivation modelled across the United States.
From: The greenhouse gas emissions of indoor cannabis production in the United States




The caption:

a, Cumulative GHG emissions from cultivating cannabis indoors interpolated within eGRID electricity region boundaries. eGRID, Emissions and Generation Resource Integrated Database. b, Natural gas required to maintain indoor environmental conditions. c, Electricity required to maintain indoor environmental conditions and high-intensity grow lights. d, GHG emissions for the US electricity regions modelled. Full resolution figures are provided in Supplementary Figs. 1–4.


Fig. 2: Breakdown of life cycle GHG emissions contributions from indoor cannabis cultivation.



The caption:

GHG emissions from indoor cannabis production at ten of the 1,011 locations modelled. The GHG emissions totals represent individual simulation results based on modelling input parameters specific to each location. The positive values represent released GHG emissions and the negative value represents stored GHG emissions based upon the model system boundary. The HVAC labels in the main figure refer to the major equipment used to manipulate outside air to meet inside condition criteria, whereas the indoor environmental controls in ‘Other’ are supplemental (suppl.) systems representing additional equipment located inside grow rooms that aid in maintaining environmental conditions.


Some technical details of growing conditions:

The HVAC systems are responsible for modifying air temperature and humidity to an allowable range before being supplied to the cannabis plants. This is critical to maintaining plant health as sudden changes in temperature and humidity can shock the plants and ultimately lead to crop damage and product loss. Additionally, cannabis plants require a regular supply of fresh air to help moderate humidity and oxygen levels. In this work, an air supply rate of 30 volumetric air changes per hour (ACH) was assumed. This value represents the average value from the literature, which reports values as high as 60 ACH and as low as 12 ACH (Supplementary Table 1). For comparison, the recommended ventilation for homes is 0.35 ACH and operating rooms in hospitals require a minimum of 15 ACH15,16. Air condition modifications and supply by HVAC are cumulatively shown to be the largest contributor to overall GHG emissions regardless of location (see Supplementary Table 2 for all contributions).


"ACH" apparently plays a big role:

Fig. 3: Sensitivity analysis of ACH.

From: The greenhouse gas emissions of indoor cannabis production in the United States



The caption:

Impact of ACH on GHG emissions from indoor cannabis cultivation for the same ten locations displayed in Fig. 2. The baseline assumption for this study was 30 ACH, shown in red.
'

Some commentary in the conclusion:

Although there are many hurdles associated with shifting cannabis growth to legal and well-regulated greenhouse and outdoor cultivation practices, preliminary investigations into the potential difference in GHG emissions when switching to greenhouse and outdoor cultivation practices indicated reductions of 42 and 96%, respectively6,7. It is important to note that these reports are limited in scope and resolution as the GHG emissions are based primarily on electricity consumption through monthly bills. Therefore, the current state of the industry would benefit from understanding the true GHG emissions of greenhouse and outdoor cultivation at a similar resolution to the work presented here to allow real comparison between the three cultivation methods. The results of this study affirm that more than 80% of the GHG emissions from all indoor cannabis locations assessed are caused by practices directly linked to indoor cultivation methods, specifically indoor environmental control, high-intensity grow lights and the supply of CO2 for increased plant growth. If indoor cannabis cultivation were to be fully converted to outdoor production, these preliminary estimates show that the state of Colorado, for example, would see a reduction of more than 1.3% in the state’s annual GHG emissions (2.1 MtCO2e)24.


Was it Bob Dylan who said: "I would not feel so alone; everybody must get stoned?"

Whatever.

All this expense, for no other reason than the need to avoid reality...

History will not forgive us, nor should it.

Have a nice day tomorrow.
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