Alessandro Macario, Ph.D

Researcher in Behavioural and Evolutionary Ecology interested in mate choice, social behaviour and cognition.

[Science girl @sciencegirl]

Scientists have identified previously unknown chemicals in the atmosphere above the Amazon rainforest following the severe drought that affected the region during 2023 and 2024.

While monitoring air samples above the forest canopy, researchers discovered that trees were releasing unusual compounds called sesquiterpene alcohols, including a substance known as beta-eudesmol. These chemicals had not been detected in Amazon rainforest air before.

What surprised researchers most was the timing. The compounds appeared after rainfall had returned and continued to be released for several weeks after drought conditions had eased.

Trees naturally emit a variety of chemicals into the atmosphere, some of which help protect them from environmental stress or act as signals when they are exposed to extreme conditions such as heat and water shortages. During the drought, scientists observed that concentrations of known stress-related compounds increased to more than twice their usual levels. As the forest began to recover, an entirely new set of chemicals emerged.

Researchers suspect these emissions may be connected to the way trees respond to and recover from drought-related damage, although further studies will be needed to determine their exact function.

The discovery could have wider implications for the Amazon ecosystem and the atmosphere above it. These compounds can contribute to the formation of tiny airborne particles that affect cloud development, the amount of sunlight reaching the surface, and local weather patterns. Scientists warn that if severe droughts become more frequent in a warming climate, these newly observed emissions could become a more regular feature of the rainforest atmosphere.

Source: "Intense El Niño provokes production of new reactive volatiles as stress defences in Amazon rainforest." Communications Earth & Environment.

[Science Magazine @ScienceMagazine]

A new Science study shows that bumble bees can position a ball underneath a fake “flower” to reach a reward, suggesting they can exhibit spontaneous problem-solving and challenging the notion that such advanced cognitive abilities are exclusive to large-brained vertebrates.

Learn more: https://t.co/T964qkIQzx

[David Sinclair @davidasinclair]

After 25 years of brave & brilliant work by hundreds of scientists in my lab to understand then safely reverse aging for the first time, it was moving to witness the first human dose being delivered 🥹 https://t.co/veQsyUEORz

[B'Tselem בצלם بتسيلم @btselem]

תיעוד חדש שהגיע לידי בצלם חושף את רגעי הירי במשפחת אבו הייכל, שכתוצאה ממנו נהרג סאם אבו הייכל, תינוק בן 7 חודשים, ונפצעו שני הוריו. מהתיעוד עולה בבירור כי הירי שביצע החייל לעבר הרכב בוצע בזמן שנהג הרכב האט את נסיעתו לקראת עצירה, וכאשר היה במרחק מהחיילים ולא היווה כל סכנה עבורם.

בהמשך, בסרטון נוסף שהגיע לידי בצלם, נראה פאהד, אביו של סאם בן ה-7 חודשים, ברגעים הראשונים לאחר הירי בבנו. האב נראה כאשר הוא אוחז בתינוק ומנסה לעצור בידיו את הדימום מראשו. עוד ניתן לראותבתיעוד את אימו של התינוק, דאניה, שנפצעה גם היא מהירי בזמן שאחזה בבנה, כשהיא יושבת על הכביש לצד רכב המשפחה.

ביום שישי האחרון, 5 ביוני, חייל ישראלי פתח באש קטלנית לעבר משפחה פלסטינית, שחזרה מביקור משפחתי, בעת שנסעה ברכבה בשכונת תל רומיידה בחברון. הירי בוצע לאחר שאב המשפחה, שנהג ברכב, הבחיןבחיילים שעמדו על הכביש והאט. סאם, תינוק בן 7 חודשים, שהיה באותה עת בזרועותיה של אימו במושב האחורי, נפגע בראשו מהירי ומותו נקבע זמן קצר לאחר מכן. מהירי נפצעו גם אביו של סאם ואימו, שעדייןמאושפזת בבית החולים. לאחר הירי החייל היורה וחייל נוסף שהיה עמו עזבו את המקום מבלי לבדוק את הרכב ומבלי להגיש סיוע לתינוק הפצוע אנוש ולאימו.

בשנתיים וחצי האחרונות ישראל הרגה למעלה מ-20,000 ילדים בעזה ובגדה המערבית. החסינות שהמערכת הישראלית מעניקה לחיילים ולמתנחלים הובילה למציאות יומיומית בה הרג של פלסטינים, באשר הוא, נתמך ומגובה על ידי המערכת - אפילו כשמדובר בתינוק בן 7 חודשים.

[Science Magazine @ScienceMagazine]

Recent studies have revealed the synchronization of neuromodulators including norepinephrine, serotonin, acetylcholine, dopamine, and histamine during sleep.

A new #ScienceReview explores what potential role the synchronization of these oscillations may play in health.

Learn more: https://t.co/CgXBMMdEJb

[Science Magazine @ScienceMagazine]

New @ScienceAdvances research finds that heat stress can disrupt and eventually destroy corals’ cilia-based ventilation systems. https://t.co/rcyKx33NWz

[Science girl @sciencegirl]

Like a butterfly

Display of the Bohemian Waxwing bird

📹 wildsafarisaga and birdsinbloom

wild Safari Saga

[Prof. Stefan Rahmstorf 🌏 🦣 @rahmstorf]

📣 Just out: our new study on the 'cold blob' in the Northern Atlantic. Is that due to ocean currents bringing less heat there, or due to more heat being lost through the sea surface?
Our data analysis strongly suggests it's due to #AMOC slowing.

https://t.co/Po7mmOSiGC

[Science Magazine @ScienceMagazine]

In a 2025 @SciImmunology Review, researchers discussed how interactions between the nervous and immune systems could impact neurological disorders and allergy-related behaviors like food avoidance.

Learn more: https://t.co/rhVox5E0Fx #ScienceMagArchives

[Vincent Gaudin @vincentgaudin]

Vous aimez les chiffes ?
Le #marathon en 1h58 ?
Après ce 26 avril et les 1h59'30" de Sawe, voici une analyse de l'évolution des meilleures performances mondiales sur marathon de 2021 à 2026.

https://t.co/kLNku3pPST @relancemag

[Alessandro Macario, Ph.D @AlessandroMaca]

@franceinter Ni charisme, ni convictions à part celle de sa propre ambition. Phrases creuses, idées floues et éléments de langage en pagaille. De droite je me réjouirais de faire face à une opposition aussi faible. De gauche je vois en lui (et ses semblables) les causes de la defaite.

[Alessandro Macario, Ph.D @AlessandroMaca]

@franceinter Ni charisme, ni convictions à part celle de sa propre ambition. Phrases creuses, idées floues et éléments de langage en pagaille. De droite je me réjouirais de faire face à une opposition aussi faible. De gauche je vois en lui (et ses semblables) les causes de la defaite.

[Science girl @sciencegirl]

Moth from the genus Phalera

It looks like a fragment of twig complete with chipped bark and even the layering of wood tissue at the “cut” ends

perfectly resembling a broken piece of wood to avoid predation.

📹Bart Coppens/ coppensb

[William A. Wallace, Ph.D. @WilliamWallace]

Coffee is not one drink. It is a category. The bean and water are constant across most home brewing, but the method changes which compounds end up in your cup. Two cups from the same bag can deliver very different chemistry depending on how they were brewed.

Four compounds matter for health. Caffeine drives the stimulant effect. Chlorogenic acids are the main polyphenols in coffee and carry most of its antioxidant activity. Diterpenes, specifically cafestol and kahweol, are oils that suppress the liver enzyme responsible for converting cholesterol into bile acids. When that enzyme slows, less cholesterol gets cleared and LDL goes up. Bitter phenolics accumulate with long extractions.

What the method controls. Angeloni et al. (Food Res Int 2020) compared eight brewing methods using the same beans. Espresso had the highest caffeine and polyphenol concentration per milliliter, three to six times more concentrated than drip or moka. But a shot of espresso is 30 mL. A cup of cold brew is 240 mL. Per cup, cold brew delivers more total caffeine and polyphenols because the serving is roughly eight times larger.

Diterpenes are where brewing method matters most for cardiovascular risk. They are oil-soluble, so a paper filter can physically trap them. Orrje et al. (NMCD 2025) measured these across methods. Paper-filtered drip: about 12 mg/L cafestol. French press and percolator: around 90 mg/L. Boiled coffee: 939 mg/L. Some espresso shots reached 2,447 mg/L, though espresso is highly variable. The paper filter is the key. Methods without one let the oils through.

This is why brewing method affects cholesterol. Jee et al. (Am J Epidemiol 2001) pooled fourteen randomized trials. Unfiltered coffee raised total and LDL cholesterol. Filtered coffee did not. Svatun et al. (Open Heart 2022, N=21,083) confirmed the signal in Norway. Drinking six or more cups of boiled or French press coffee daily was associated with total cholesterol about 9 to 12 mg/dL higher than non-drinkers. Filtered coffee showed only a small effect, mostly in women.

A note on the numbers. The per-cup mg values are estimates from per-mL concentrations times typical serving volumes. The relative ordering across methods is well-supported. Exact amounts depend on dose, grind, temperature, time, and bean. Espresso varies the most.

A note on cold brew. The graphic assumes paper filtration, which most commercial cold brew uses. Home cold brew through metal mesh or cheesecloth retains more oil and more diterpenes. The filter matters as much as the method.

The takeaway. If you want the caffeine and polyphenols without raising LDL, use paper-filtered methods. Espresso gives you concentrated chemistry in a small serving. French press and boiled coffee give you everything including the oils that raise LDL. Coffee is not one drink. The brewing method is the variable.

Angeloni et al., Food Res Int 2020 · Orrje et al., NMCD 2025 · Jee et al., Am J Epidemiol 2001 · Svatun et al., Open Heart 2022

[Nicholas Fabiano, MD @NTFabiano]

Kids who read more tend to have larger brain surface areas in regions for cognition. 

Kids who watch more TV show the opposite.

[Science Magazine @ScienceMagazine]

Lab-kept bumble bees roll small wooden balls around for no apparent purpose other than fun, a 2022 study revealed.

Learn more on #WorldBeeDay: https://t.co/Jw11mAIuiN

[Gabriel Zucman @gabriel_zucman]

New research: we have studied the wealth of the 200 Californian billionaires and what they effectively pay in tax.

From Mark Zuckerberg (Meta) to Sergei Brin and Larry Page (Alphabet), the results are edifying. 🧵

https://t.co/lW5UaGhYHY

[Alessandro Macario, Ph.D @AlessandroMaca]

@franceinter Non Mr Sansal vous ne valez pas 1M€. Vous êtes un idiot utile, un pion dans un jeu qui de toute evidence vous depasse totalement. Si prompt à denoncer la dictature en Algerie, si naïf en politique française. P.S. Espérons que vous vous exprimiez mieux à l'écrit qu'à l'oral 🛶🛶

[Alessandro Macario, Ph.D @AlessandroMaca]

@cremieuxrecueil @adam_dorr Certainties are often dangerous, at best naive, but above all stupid. Such claims are dogmatic, ideologically driven and go against what science is all about. The only certainty is that nothing is certain hence the crucial role of statistics.

[Adam Rochussen @AdamRochussen]

This is probably the worst p-hacking I’ve ever seen. Let’s go along with the validity of the “brain sex index”, for argument’s sake. The actual result shows that the men and the trans women did not significantly differ at all, but trans women and biological women did significantly differ. The authors just pretended otherwise via some insane statistical acrobatics.

They had three groups of 24 people each. The trans group is clearly not normally distributed (more on that later). They should have performed a Kruskal-Wallis test with Dunn’s multiple comparisons test. Instead, they did ANOVA and then *one-tailed* *unadjusted* t-tests for their post-hoc comparisons.

With this method, they found men vs trans women differed by d=0.64, p=0.016. But women vs trans women differed by d=1.87, p<0.001. So trans women are slightly more female than non-trans males. Narrative supported by data! Hooray! And to make it seem like it’s kind of half-way, they just give both of those p-values a single asterisk on the plot.

If they had instead done a two-tailed test, this doubles the p-value. And if they had done a Bonferroni correction for two comparisons, the p-value doubles again. They also should’ve done three comparisons really (men vs women isn’t tested in their paper—for no good reason), so triple instead of double the p-value.

So in reality, a proper analysis of their data without cherry-picking and biased hypothesis testing would’ve resulted in the difference between men and trans women being non-significant (p=0.096), but the difference between women and trans women remaining very significant (p<0.006). Narrative destroyed by data. Uh oh.

Going back to the squiggly distribution in the trans group. Of the 24 trans participants, 6 were androphiles (ie gay males), 18 were gynephiles (straight males). I don’t know for sure, because the authors didn’t share the underlying data, but it seems plausible that sexual attraction might be more important for their “brain sex index” than gender identity. We also don’t have sexual preference info for the non-trans groups, and in general the sample size is way too tiny to get fancy with multivariate analysis like this. It’s even too tiny for the main analysis: if someone wanted to replicate the d=0.64 difference properly, they’d need at least 53 people per group.

Anyways, if you want to support the wellbeing of trans people, which hopefully we all do, I don’t think twisting data to publish headline-grabbing fake conclusions is that way to go about it. It’s just going to make people irate when the statistical malpractice is pointed out, and then backfire on the trans “movement”. We really should stop attaching moral valence to data and stop trying to leverage the authority of science as a political tool.