US president-elect Joe Biden has chosen the decorated geneticist Eric Lander as his presidential science adviser and the director of the Office of Science and Technology Policy (OSTP). If Lander’s appointment is confirmed by the US Senate, he will serve as a member of Biden’s cabinet — a first for this position.

Many scientists have long called for the OSTP director to be raised to a cabinet-level position. “Having science elevated to its rightful place in the administration seems to me a very positive step,” says Harold Varmus, a cancer researcher at Weill Cornell Medicine in New York City and a former head of the US National Institutes of Health (NIH). “I think it marks a very important moment in the history of science in the government.”

“It signifies the importance of who will be in the room when decisions are being made,” says Roger Pielke Jr, who studies science policy at the University of Colorado Boulder.

Lander was a key figure in the Human Genome Project — the race to sequence the human genome, which ended in 2003 — and is the president and founding director of the Broad Institute of MIT and Harvard in Cambridge, Massachusetts. He will be the first biologist to run the OSTP.

Between 2009 and 2017, he co-chaired the President’s Council of Advisors on Science and Technology (PCAST), an elite panel that advises the US president. Among the PCAST reports issued during Lander’s tenure were some dealing with energy, climate change and vaccine response in the face of pandemic influenza...

… Nobel laureate Frances Arnold, a bioengineer at the California Institute of Technology in Pasadena, and Maria Zuber, a geophysicist at MIT, will co-chair PCAST under Biden. Alondra Nelson, nominated to be deputy director for science and society at the OSTP, is a social scientist at the Institute for Advanced Study in Princeton, New Jersey, who studies genetics, race and other societal issues.

“These are excellent appointments, highly qualified and experienced, and well grounded in science,” Rita Colwell, a microbiologist at the University of Maryland at College Park and a former director of the US National Science Foundation, wrote to Nature in an e-mail...

Fig. 1. The coffee plant.

Coffee is an important plantation crop belonging to the family Rubiaceae, subfamily Cinchonoideae and tribe Coffeae (Clifford et al., 1989). The Rubiaceae members are largely tropical or subtropical comprising nearly 400 genera and 4800–5000 species. Botanically, coffee belongs to the genus Coffea of the family Rubiaceae. The sub-genus Coffea is reported to comprise over 80 species, which are prevalent in Africa and Madagascar (Bridson and Verdcourt, 1988). Coffee is a perennial plant and evergreen in nature (Fig. 1). It has a prominent vertical stem with shallow root system, the feeder roots of arabica coffee penetrate relatively deeper into the soil whereas robusta has feeder roots concentrated very close to the soil surface.

Coffee leaves are opposite decussate on suckers. The leaves appear shiny, wavy, and dark green in color with conspicuous veins. The inflorescence is a condensed cymose type subtended by bracts. Coffee is a short day plant and hence the floral initiation takes place in short day conditions of 8–11 h of day light. Pollination takes place within 6 h after flowering (Fig. 2). Arabica coffee is autogamous with different degrees of natural cross-pollination in contrast to Robusta coffee, which is strictly allogamous with an inbuilt ametophytic system of self-compatibility. The process of fertilization is completed within 24–48 h after pollination. Seeds are elliptical or egg shaped and the seed coat is represented by the silver skin which is also made up of scleroides. The size, thickness or number of pits in the walls of scleroides is considered as important taxonomic characters in differentiating between species. Germination takes place in about 45 days.

Fig. 2. Coffee flowers blossomed in the estate.

Fig. 3. Coffee pulping using pulper in wet processing of coffee.

Fig. 4. Coffee drying in the drying yards after wet processing.

Fig. 5. Coffee roasting to obtain volatiles.

Fig. 6. Cross-section of the coffee cherry.

Fig. 7. (a) Sketch of the production of various by-products from coffee industry. (b) Coffee by-products obtained during coffee processing.

In Ernest Hemingway’s “The Sun Also Rises,” someone asks Mike Campbell, the troubled Scottish war veteran who is engaged to Lady Brett Ashley, how he ended up bankrupt. “Two ways,” Campbell replies. “Gradually, and then suddenly.” Campbell’s interlocutor goes on to ask what brought about his collapse. “Friends,” Campbell says. “I had a lot of friends. False friends. Then I had creditors, too. Probably had more creditors than anybody in England.”

It’s too early to determine whether Donald Trump might be headed for the same fate as the wretched Campbell, but there are intriguing parallels. Not so long ago, Trump also had lots of friends and creditors...

...His most important creditor was Deutsche Bank, which, during the past decade, had defied internal dissension and extended hundreds of millions of dollars of loans to him. On top of these invaluable relationships, Trump had nearly ninety million Twitter followers, a vast audience that appeared to provide lucrative possibilities for monetization after he left office.

But, in the week since Trump incited a mob of his supporters to attack the Capitol, he and his businesses have suffered a series of blows. Key corporate partners have abandoned him; some of his fellow-billionaires have spoken out against his sedition; Deutsche Bank has let it be known that it doesn’t want anything more to do with him; and Twitter stripped him of his following...

... Trump’s attempt at a Presidential “self-coup” came at what was already a troubled time for the Trump Organization, which has consistently struggled to eke out much in the way of taxable profits. As the coronavirus ravaged the travel and hospitality industries in 2020, Trump-owned hotels and golf resorts suffered along with other businesses in these sectors. Like other companies, the Trump Organization shuttered some of its properties for several months, including a hotel in Las Vegas and golf courses in Florida, Scotland, and Ireland. The virus also impacted two of Trump’s most valuable real-estate assets: a pair of prime office towers that he co-owns with Vornado Realty Trust...

...Shortly after Trump lost the election, according to the Washington Post, one of his closest business associates, the real-estate investor Tom Barrack, called Trump and advised him to abandon his efforts to overturn the result, and to opt, instead, for an “ ‘elegant’ exit...”

...Trump ignored it.

...After the deadly violence at the Capitol, on January 6th, the financial blowback on Trump came quickly. Within twenty-four hours, Shopify, the e-commerce provider, shut down a number of online stores affiliated with Trump, including ones that sold Trump campaign merchandise. A bigger blow for the President came last Sunday, when the P.G.A. of America, which has had a long-standing relationship with him, announced that the 2022 P.G.A. Championship, one of professional golf’s four major tournaments, would no longer be held at the Trump National Golf Club in Bedminster, New Jersey. Twenty-four hours later, the R. & A., the ruling body of golf outside of the United States, followed the P.G.A.’s lead and announced that, for the foreseeable future, the British Open would not be played at Turnberry, a famous old course that Trump owns in Scotland...

Dr. Bahar currently resides in Pittsburgh. She came to the United States to become a professor at University of Pittsburgh, Department of Molecular Genetics & Biochemistry in 2001. Notably, she is the first Turkish female scientist elected to the National Academy of Sciences of the United States.[4] In 2016, she was invited by President Barack Obama as a guest speaker to the White House to give a speech titled "Big Data in Multiscale Modeling and Biology".[5]

I got my bachelor’s from the University of Dayton in biology, and I had a minor in computer science. After realizing that medical school was not for me, I was quite interested in blending my curiosity for mathematics and programming with my long-term excitement for biology. Initially, I did not know anyone in the field of computational biology, but I had mentors and advisors who pushed me in the direction of relevant resources, since the University of Dayton didn’t have a computational biology curriculum. By the time I completed a bioinformatics Research Experiences for Undergraduates (REU) program at the University of Pittsburgh, I realized that I wanted to pursue a PhD in this field, not only because it was an exciting field research-wise, but also due to the diversity in terms of people’s backgrounds. Eventually, this led me to the University of Pennsylvania, where I have been working with computational genomics...

...My main role model was Ivet Bahar from the University of Pittsburgh, who was my advisor during my REU program. I saw a really powerful woman leading an important department at the university and in computational science, and she inspired me to reach for more and think outside of my comfort zone. At the time, I didn’t know many women in the field, and I certainly didn’t know any women who looked like me in the field, so she was definitely inspiring to me...

... It was honestly a natural process. I decided to search for ‘number of Black women with degrees in computational biology’ on the Internet and found nothing. There was an editorial on women in the field, but nothing relevant to race or ethnicity demographics of the field. I didn’t put that much thought into it, but I knew that someone like me was going to really appreciate being able to find other Black women by doing a simple search...

... Now, we have a new website that is so much more and symbolizes our growth into a full organization. The next person that searches for Black women in computational biology will be able to find us...

The unique material properties of plutonium make it a possible source of heat to generate steam in power production or to power radioisotope thermoelectric generators for space probes and, once upon a time, in pacemakers.(1) However, even trace amounts of hydrogen gas or water vapor dissociatively absorb in plutonium because of the high inherent reactivity of the metal. Above a temperature-dependent solubility limit, the absorbed H atoms aggregate to form plutonium dihydride (PuH2) flakes or powder.(2) Plutonium hydride can further catalyze rapid, catastrophic oxidation or induce pyrophoricity,(3) generating toxic waste. As a result, understanding plutonium corrosion properties is of primary importance for its continued use in many application areas.

The complexities of plutonium hydriding can be illustrated by a comparison to hydriding in a more common metal, such as palladium. The critical temperature of the palladium–palladium hydride phase envelope is 550 K (277 °C), well below the palladium metal melting temperature of 1828 K (1555 °C).(4) In contrast, solid plutonium dihydride (PuH2) will crystallize from liquid Pu that is exposed to hydrogen gas.(5) In addition, hydriding in face-centered cubic (fcc) ?-Pu (of interest for engineering applications because of its high ductility(6)) induces a large volume expansion of 54%, compared to an expansion of only ?10% in palladium hydriding, resulting in flaking and the complete degradation of Pu-based materials because of this lattice mismatch. Finally, neutron diffraction reveals that H atoms randomly occupy interstitial octahedral (O) sites in palladium hydride.(7) In contrast, no neutron diffraction studies have been performed on ?-Pu or PuH2 to indicate how H atoms partition between O sites and tetrahedral (T) sites, though investigations of lanthanide hydrides show that O sites are not occupied until all available T sites are filled.(8)

Conducting experiments with plutonium is exceedingly difficult because of its toxicity and radioactivity. The lowest temperature at which the composition of the PuH2 phase has been reported is 773 K (500 °C).(5) Mulford and Sturdy additionally reported equilibrium pressures at 673 and 723 K (400 and 450 °C) but were unable to determine the equilibrium compositions at these temperatures, reporting that it took 20 h to equilibrate at each trial composition...

...Conducting experiments with plutonium is exceedingly difficult because of its toxicity and radioactivity. The lowest temperature at which the composition of the PuH2 phase has been reported is 773 K (500 °C).(5) Mulford and Sturdy additionally reported equilibrium pressures at 673 and 723 K (400 and 450 °C) but were unable to determine the equilibrium compositions at these temperatures, reporting that it took 20 h to equilibrate at each trial composition. Allen(9) and Richmond et al.(10) both published equilibrium pressures but only determined the lower solubility limit of H in Ga-stabilized ?-Pu and not the upper limit in the PuH2 phase...

...This scarcity of experimental data for bulk plutonium hydriding makes computer model prediction particularly attractive for possible chemical and environmental studies. Recent efforts have utilized density functional theory (DFT) to assess the crystal structure, density, magnetization, conductivity, elasticity, and reactivity of plutonium(11?18) and plutonium hydrides.(19?22) These properties were computed from energy-minimized configurations at zero kelvin, which excludes potentially important thermal effects on the free energy as a function of composition...

The Hamiltonian of a PuHx lattice gas in the grand canonical ensemble is



where the configurational potential energy Econfig, the vibrational free energy Fvib, and number of hydrogen atoms NH are properties of the microstate while the chemical potential of a gas-phase hydrogen molecule ?H2, the number of plutonium atoms NPu, and the temperature T are held constant. Each absorbed H is treated as an independent quantum harmonic oscillator. Consequently, eq 1 contains the analytic free energy Fvib rather than a potential energy Evib and corresponding quantum degrees of freedom. A P?V term for H in the Pu lattice is not included in eq 1 because under the conditions studied here, its value is several orders of magnitude smaller than other terms. The impact of plutonium defects on Pu–PuH2 equilibrium is not considered in this work...

...Because of the likely strong screening effects of the intervening plutonium atoms, we parameterize the change in energy using only the number of occupied nearest neighbor sites surrounding an occupied O or T site. This results in three types of H–H structures: those comprised of hydrogens in neighboring T sites (ETT), those in neighboring O sites (EOO), and cross-interactions (EOT). As will be shown, all OO and OT structures are sufficiently energetically prohibitive as to be rare in either ?-Pu or PuH2 phases. Accordingly, we ignore the change in energy induced by an OO structure when OT structures are present because the latter increase the energy significantly more than the former. The configurational potential energy is



where ni is 1 if site i is occupied and 0 otherwise, and the function EOT accounts for H–H interactions between a hydrogen in an O site and the NiT hydrogens in the nearest neighbor T sites. ETT, EOO, and NiO are defined similarly. The number of occupied neighbors NiT and NiO are computed using periodic boundary conditions. The first sum is over T sites, the second sum is over O sites, and the Heaviside function ? (x) is 1 if x ? 0 and 0 otherwise.

Zero-point energies and entropic contributions from the vibration of light interstitials such as H in metals can be significant. Changes in the plutonium vibrational frequencies are not included because Pu atoms are much heavier than the absorbed H atoms. The insertion of a hydrogen atom, on the other hand, creates three vibrational modes that did not exist in the previous configuration. These modes are treated as quantum harmonic oscillators, with the following analytical free-energy expression

where ni is 1 if site i is occupied and 0 otherwise, and the function EOT accounts for H–H interactions between a hydrogen in an O site and the NiT hydrogens in the nearest neighbor T sites. ETT, EOO, and NiO are defined similarly. The number of occupied neighbors NiT and NiO are computed using periodic boundary conditions. The first sum is over T sites, the second sum is over O sites, and the Heaviside function ? (x) is 1 if x ? 0 and 0 otherwise.

Zero-point energies and entropic contributions from the vibration of light interstitials such as H in metals can be significant. Changes in the plutonium vibrational frequencies are not included because Pu atoms are much heavier than the absorbed H atoms. The insertion of a hydrogen atom, on the other hand, creates three vibrational modes that did not exist in the previous configuration. These modes are treated as quantum harmonic oscillators, with the following analytical free-energy expression



Here, ?ij is the vibrational temperature ℏ?ij/kB for frequency ?ij of a hydrogen in site i along normal mode j. We parameterized ?ij as a function of NiT to account for the decrease in ?ij as the plutonium lattice expands with the absorption of hydrogen...

Figure 1. Snapshots of DFT-optimized PuHx configurations. Pu atoms are gray, H atoms in O sites are blue, and H atoms in T sites are red.

Figure 2. Change in potential energy for inserting a hydrogen into a site with the specified number of occupied neighboring sites. Filled symbols indicate parameters computed from DFT energies while open symbols were determined from linear interpolation.

Figure 3. (Left) 2D free energy projected onto the number of hydrogen atoms in O sites NHO and in T sites NHT at 673 K for a system of NPu = 32 and reweighted to . Dashed lines show the boundaries of integration for determining . (Right) ?-Pu, PuH2, and metastable multiphase configurations. The corresponding location of each configuration on the free-energy surface is indicated by an arrow. Pu atoms are gray, H atoms in O sites are blue, and H atoms in T sites are red.

Figure 4. (a) Free energy normalized by NPu projected onto the ratio of hydrogen-to-plutonium atoms at temperature 673 K for systems of NPu = 4 (light blue), 32 (black), 108, 256, and 500 (dark blue) and reweighted to the equilibrium chemical potential. (b) Equilibrium chemical potential as a function of system size. Error bars are smaller than the symbol size.

Figure 5. Free energy projected onto the ratio of hydrogen-to-plutonium atoms for a system of NPu = 32 at temperatures 298, 373, 473, 573, 673, 723, and 773 K and reweighted to the equilibrium chemical potential for (a) the ?-Pu basin and (b) the PuH2 basin. The gray arrow shows the direction of increasing temperature. (c) Van’t Hoff plot of equilibrium pressures from experiment (red triangles,(5) blue squares,(9) and green filled circles(10)), and simulation (black open circles). Error bars on simulation data are smaller than the symbol size.

Our lattice gas approach accounts for H–H interactions in nearest neighbor O and T sites and leverages a tractable number of energies computed via DFT. This allows for the calculation of accurate Pu–PuH2 phase envelopes at a fraction of the cost of standard quantum mechanical approaches. Our results yield quantitative agreement with direct experimental measurements of the solubility limits of hydrogen in plutonium at high temperatures but are higher than previous extrapolations to room-temperature solubilities by six orders of magnitude. We predict the heat of formation of PuH2 to within 7–16 kJ/mol of the experimental range of results...

...We anticipate that our lattice gas model could be parameterized to examine the hydride phase envelopes of other fcc actinides, rare earth metals, or transition metals (e.g., thorium, cerium, and palladium). Overall, our predictions provide a baseline to guide future plutonium experiments...