Pulitzer-winning cartoonist Mike Luckovich had a middle-of-the-night inspiration after Super Tuesday.

• As the coronavirus-led economic shutdown drags on, many investors have started counseling startups to have more than a years' worth of "runway" to avoid having to raise funding on poor terms.
• But VCs are split on how much startups should be socking away. Some have estimated 18 months oof reserves could suffice, while others say as much as 3 years' worth of runway is ideal.
• The different time frames depends on the age of the startup along with which industry they operate in. Younger startups typically have fewer overhead expenses, while older startups likely have more employees and pricey office leases.
• Also, those companies that may be able to resume work as essential services may need less cash if they are able to generate revenue.
• VCs are uniformly bracing for an economic slowdown, but the severity of downturn is still up for debate. 
• Click here for more BI Prime stories.

Startups are facing what could become the worst economic downturn in several decades, and VCs are begging them to take drastic measures to improve their chances of making it through. 

Most Americans who lived through the 2008 financial crisis will know that a savings stockpile or rainy day fund can mean the difference between surviving and thriving during tough times, but as recent studies have shown, many tech startups and VC firms don't have a similar first-hand experience; many have only known boom times and are now venturing into uncharted waters.

One thing VCs agree on is that startups need to quickly rein in growth plans — ideally as soon as yesterday — and start scrutinizing expenses. Anything nonessential should be cut or suspended indefinitely, headcount should be reduced, and pricey office leases eliminated if possible, all with the goal of extending a startup's "runway."

In Silicon Valley, runway refers to how much cash a startup has on hand to put against its operating expenses. If, for example, a startup has roughly $100,000 in monthly operating expenses and has $1 million in the bank, they are looking at a 10-month runway, assuming revenue stays roughly flat.

In the days before the coronavirus pandemic, a startup's runway dictated when it had to start looking for additional funding. Instead of cutting expenses, the popular solution was to simply put more VC money in the bank. This helped high flying startups like Uber and Airbnb expand at a breakneck pace — VC dollars kept pouring in and the companies remained unprofitable as they chased growth at all costs.

But now, VCs are saying that's no longer an option. Founders Fund general partner Keith Rabois said on a podcast recently that profitability is now being rewarded much more than high-growth. 

For startups that aren't profitable, that means hunkering down and ensuring there are enough reserves to last through the crisis.

So how long does the runway need to be? 

Many VCs that Business Insider has spoken to are advising their startups to have at least 18 months of runway. But some VCs say startups should have upwards of 3 years' of expenses saved up. 

The length of time can vary depending on the startup, one investor told Business Insider, pointing to the startup's age and industry as important factors. An early-stage company with a handful of employees and low-overhead costs might easily stretch a $500,000 seed check, whereas a growth-stage biotech startup with hundreds of employees, expensive hardware, and pricey office space might struggle to make tens of millions of dollars in funding make it through 12 months. Those that can't cut costs will be forced to fundraise with poor terms and risk the dreaded downround. 

"You can always easily dial back up the aggressiveness and risk profile if we get more optimistic visibility, but if you don't take action right away — to preserve capital, cut your burn rate, have fundamentally attractive unit economics, edit the product to make more sense in the new world order — if you don't do those right away, the opportunity to do those things and survive is probably lost forever," Rabois said in the April Talkshow broadcast.

Rabois is in the camp of pessimists, generally speaking, who think the economic downturn will not only drag on through 2020, but could eventually turn into an economic depression the likes of which could rival the Great Depression of the 1930s. He said that his VC peers are starting to rein in the freewheeling deal-making that has defined the last two decades of the Silicon Valley startup ecosystem, and are now treading cautiously. It's time that startups do the same, he said.

SEE ALSO: Lower valuations and a long wait for funding: Two top early-stage VCs dish on how they are counseling startups to withstand long-term economic uncertainty

Join the conversation about this story »

NOW WATCH: Pathologists debunk 13 coronavirus myths

‘The idea that what’s happening with searcher behavior is not causing these shifts means that Google is in there writing that code for every intent, every day, and I can’t believe that’s what’s happening,’ said Dr. Pete Meyers on Live with Search Engine Land.

Please visit Search Engine Land for the full article.

BEST DEALS ON GAMING LAPTOPS:

• MSI - Modern 15 15.6" Laptop — $749

• ASUS - ROG G531GT 15.6" Gaming Laptop — $999.99

• Dell - G3 15.6" Gaming Laptop — $999.99

It's time to level up.

If you didn't already know, PC gamers take great pride in the way they play. These are the folks who delight in the fact that PC gaming is just so much better than playing on a console, and if this Reddit thread is any indication — this way of thinking isn't going away any time soon.

While it can take a year or two for gaming consoles to adapt to updated technology, PCs see that improvement hit almost instantly. New rigs and laptops hit the market faster, as opposed to consoles that make you wait for months until their release.  Read more...

BEST DEALS ON GAMING LAPTOPS:

• MSI - Modern 15 15.6" Laptop — $749

• ASUS - ROG G531GT 15.6" Gaming Laptop — $999.99

• Dell - G3 15.6" Gaming Laptop — $999.99

My first gaming laptop cost $1,500 more than 10 years ago, and that was considered affordable. It wasn't a top-of-the-line model, but it wasn't a slouch either, sporting one of the better mid-tier graphics cards and a reliable processor/RAM combination.  

But my, how things have changed.

Today, you can go on Amazon and find plenty of laptops for less than $1,000 that would have been at least $1,500 a few years ago, thus opening doors to people who want to try out PC gaming for themselves. (And if it's Prime Day or Black Friday or Cyber Monday, you can expect deal prices to dip even lower.) But sorting through all of the options and deciding which is best presents its own unique challenge. Read more...

Zoom has become a way of life for some people as of late (despite, uh, some safety concerns), especially when it comes to work meetings. Whether it's a company-wide all hands or a team check-in, it's likely that if you're working from home due to the coronavirus pandemic, you've had to see your coworkers' shining faces in a video call. 

Actor, writer, and Groundlings comedian Caitlin Reilly perfectly encapsulated that one co-worker you just can't stand during these video meetings:

It's so relevant it hurts. Who hasn't heard the phrase "to piggyback off of" during one of these calls?

The inspiration behind the 'tok was experiences Reilly had sitting in Zoom meetings on behalf of her boss. "I had actually never been in a zoom meeting before, so it was funny for me to see all the different 'personality' types in a situation like that," Reilly told Mashable. "And so it popped in my head one day and I just made the video." Read more...

Former Proteas head coach Ray Jennings is adamant Aiden Markram should be chosen as Faf du Plessis' replacement as captain of the Test team.

3-Mercaptopyruvate sulfur transferase (MPST) catalyzes the desulfuration of 3-mercaptopyruvate (3-MP) and transfers sulfane sulfur from an enzyme-bound persulfide intermediate to thiophilic acceptors such as thioredoxin and cysteine. Hydrogen sulfide (H2S), a signaling molecule implicated in many physiological processes, can be released from the persulfide product of the MPST reaction. Two splice variants of MPST, differing by 20 amino acids at the N terminus, give rise to the cytosolic MPST1 and mitochondrial MPST2 isoforms. Here, we characterized the poorly-studied MPST1 variant and demonstrated that substitutions in its Ser–His–Asp triad, proposed to serve a general acid–base role, minimally affect catalytic activity. We estimated the 3-MP concentration in murine liver, kidney, and brain tissues, finding that it ranges from 0.4 μmol·kg−1 in brain to 1.4 μmol·kg−1 in kidney. We also show that N-acetylcysteine, a widely-used antioxidant, is a poor substrate for MPST and is unlikely to function as a thiophilic acceptor. Thioredoxin exhibits substrate inhibition, increasing the KM for 3-MP ∼15-fold compared with other sulfur acceptors. Kinetic simulations at physiologically-relevant substrate concentrations predicted that the proportion of sulfur transfer to thioredoxin increases ∼3.5-fold as its concentration decreases from 10 to 1 μm, whereas the total MPST reaction rate increases ∼7-fold. The simulations also predicted that cysteine is a quantitatively-significant sulfane sulfur acceptor, revealing MPST's potential to generate low-molecular-weight persulfides. We conclude that the MPST1 and MPST2 isoforms are kinetically indistinguishable and that thioredoxin modulates the MPST-catalyzed reaction in a physiologically-relevant concentration range.

Invitation Only Research Event

Invitation Only Research Event

Event participants

Rebecca Wolfe, Lecturer, Harris School for Public Policy and Associate, Pearson Institute for the Study and Resolution of Global Conflicts, University of Chicago
Tom Gillhespy, Principal Consultant, Itad
Shodmon Hojibekov, Chief Executive Officer, Aga Khan Agency for Habitat (Afghanistan)
Chair: Champa Patel, Director, Asia-Pacific Programme, Chatham House

Motor protein-based active transport is essential for mRNA localization and local translation in animal cells, yet how mRNA granules interact with motor proteins remains poorly understood. Using an unbiased yeast two–hybrid screen for interactions between murine RNA-binding proteins (RBPs) and motor proteins, here we identified protein interaction with APP tail-1 (PAT1) as a potential direct adapter between zipcode-binding protein 1 (ZBP1, a β-actin RBP) and the kinesin-I motor complex. The amino acid sequence of mouse PAT1 is similar to that of the kinesin light chain (KLC), and we found that PAT1 binds to KLC directly. Studying PAT1 in mouse primary hippocampal neuronal cultures from both sexes and using structured illumination microscopic imaging of these neurons, we observed that brain-derived neurotrophic factor (BDNF) enhances co-localization of dendritic ZBP1 and PAT1 within granules that also contain kinesin-I. PAT1 is essential for BDNF-stimulated neuronal growth cone development and dendritic protrusion formation, and we noted that ZBP1 and PAT1 co-locate along with β-actin mRNA in actively transported granules in living neurons. Acute disruption of the PAT1–ZBP1 interaction in neurons with PAT1 siRNA or a dominant-negative ZBP1 construct diminished localization of β-actin mRNA but not of Ca2+/calmodulin-dependent protein kinase IIα (CaMKIIα) mRNA in dendrites. The aberrant β-actin mRNA localization resulted in abnormal dendritic protrusions and growth cone dynamics. These results suggest a critical role for PAT1 in BDNF-induced β-actin mRNA transport during postnatal development and reveal a new molecular mechanism for mRNA localization in vertebrates.

Kainate and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are two major, closely related receptor subtypes in the glutamate ion channel family. Excessive activities of these receptors have been implicated in a number of central nervous system diseases. Designing potent and selective antagonists of these receptors, especially of kainate receptors, is useful for developing potential treatment strategies for these neurological diseases. Here, we report on two RNA aptamers designed to individually inhibit kainate and AMPA receptors. To improve the biostability of these aptamers, we also chemically modified these aptamers by substituting their 2'-OH group with 2'-fluorine. These 2'-fluoro aptamers, FB9s-b and FB9s-r, were markedly resistant to RNase-catalyzed degradation, with a half-life of ∼5 days in rat cerebrospinal fluid or serum-containing medium. Furthermore, FB9s-r blocked AMPA receptor activity. Aptamer FB9s-b selectively inhibited GluK1 and GluK2 kainate receptor subunits, and also GluK1/GluK5 and GluK2/GluK5 heteromeric kainate receptors with equal potency. This inhibitory profile makes FB9s-b a powerful template for developing tool molecules and drug candidates for treatment of neurological diseases involving excessive activities of the GluK1 and GluK2 subunits.

Invitation Only Research Event

Event participants

Rebecca Wolfe, Lecturer, Harris School for Public Policy and Associate, Pearson Institute for the Study and Resolution of Global Conflicts, University of Chicago
Tom Gillhespy, Principal Consultant, Itad
Shodmon Hojibekov, Chief Executive Officer, Aga Khan Agency for Habitat (Afghanistan)
Chair: Champa Patel, Director, Asia-Pacific Programme, Chatham House

Systemic infection and proliferation of intracellular pathogens require the biogenesis of a growth-stimulating compartment. The gastrointestinal pathogen Salmonella enterica commonly forms highly dynamic and extensive tubular membrane compartments built from Salmonella-modified membranes (SMMs) in diverse host cells. Although the general mechanism involved in the formation of replication-permissive compartments of S. enterica is well researched, much less is known regarding specific adaptations to different host cell types. Using an affinity-based proteome approach, we explored the composition of SMMs in murine macrophages. The systematic characterization provides a broader landscape of host players to the maturation of Salmonella-containing compartments and reveals core host elements targeted by Salmonella in macrophages as well as epithelial cells. However, we also identified subtle host specific adaptations. Some of these observations, such as the differential involvement of the COPII system, Rab GTPases 2A, 8B, 11 and ER transport proteins Sec61 and Sec22B may explain cell line-dependent variations in the pathophysiology of Salmonella infections. In summary, our system-wide approach demonstrates a hitherto underappreciated impact of the host cell type in the formation of intracellular compartments by Salmonella.

Laser-capture microdissection (LCM) allows the visualization and isolation of morphologically distinct subpopulations of cells from heterogeneous tissue specimens. In combination with formalin-fixed and paraffin-embedded (FFPE) tissue it provides a powerful tool for retrospective and clinically relevant studies of tissue proteins in a healthy and diseased context. We first optimized the protocol for efficient LCM analysis of FFPE tissue specimens. The use of SDS containing extraction buffer in combination with the single-pot solid-phase-enhanced sample preparation (SP3) digest method gave the best results regarding protein yield and protein/peptide identifications. Microdissected FFPE human substantia nigra tissue samples (~3,000 cells) were then analyzed, using tandem mass tag (TMT) labeling and LC-MS/MS, resulting in the quantification of >5,600 protein groups. Nigral proteins were classified and analyzed by abundance, showing an enrichment of extracellular exosome and neuron-specific gene ontology (GO) terms among the higher abundance proteins. Comparison of microdissected samples with intact tissue sections, using a label-free shotgun approach, revealed an enrichment of neuronal cell type markers, such as tyrosine hydroxylase and alpha-synuclein, as well as proteins annotated with neuron-specific GO terms. Overall, this study provides a detailed protocol for laser-capture proteomics using FFPE tissue and demonstrates the efficiency of LCM analysis of distinct cell subpopulations for proteomic analysis using low sample amounts.

The study of protein subcellular distribution, their assembly into complexes and the set of proteins with which they interact with is essential to our understanding of fundamental biological processes. Complementary to traditional assays, proximity-dependent biotinylation (PDB) approaches coupled with mass spectrometry (such as BioID or APEX) have emerged as powerful techniques to study proximal protein interactions and the subcellular proteome in the context of living cells and organisms. Since their introduction in 2012, PDB approaches have been used in an increasing number of studies and the enzymes themselves have been subjected to intensive optimization. How these enzymes have been optimized and considerations for their use in proteomics experiments are important questions. Here, we review the structural diversity and mechanisms of the two main classes of PDB enzymes: the biotin protein ligases (BioID) and the peroxidases (APEX). We describe the engineering of these enzymes for PDB and review emerging applications, including the development of PDB for coincidence detection (split-PDB). Lastly, we briefly review enzyme selection and experimental design guidelines and reflect on the labeling chemistries and their implication for data interpretation.

14 November 2019

Invitation Only Research Event

Event participants

Richard King, Senior Research Fellow, Energy, Environment and Resources Department, Chatham House
Chair: Duncan Brack, Associate Fellow, Energy, Environment and Resources Department, Chatham House

29 January 2020

Policymakers are in danger of sleepwalking into ineffective carbon dioxide removal solutions in the quest to tackle climate change. This paper warns against overreliance on bioenergy with carbon capture and storage (BECCS). 

Kainate and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors are two major, closely related receptor subtypes in the glutamate ion channel family. Excessive activities of these receptors have been implicated in a number of central nervous system diseases. Designing potent and selective antagonists of these receptors, especially of kainate receptors, is useful for developing potential treatment strategies for these neurological diseases. Here, we report on two RNA aptamers designed to individually inhibit kainate and AMPA receptors. To improve the biostability of these aptamers, we also chemically modified these aptamers by substituting their 2'-OH group with 2'-fluorine. These 2'-fluoro aptamers, FB9s-b and FB9s-r, were markedly resistant to RNase-catalyzed degradation, with a half-life of ∼5 days in rat cerebrospinal fluid or serum-containing medium. Furthermore, FB9s-r blocked AMPA receptor activity. Aptamer FB9s-b selectively inhibited GluK1 and GluK2 kainate receptor subunits, and also GluK1/GluK5 and GluK2/GluK5 heteromeric kainate receptors with equal potency. This inhibitory profile makes FB9s-b a powerful template for developing tool molecules and drug candidates for treatment of neurological diseases involving excessive activities of the GluK1 and GluK2 subunits.

Invitation Only Research Event

Event participants

Rebecca Wolfe, Lecturer, Harris School for Public Policy and Associate, Pearson Institute for the Study and Resolution of Global Conflicts, University of Chicago
Tom Gillhespy, Principal Consultant, Itad
Shodmon Hojibekov, Chief Executive Officer, Aga Khan Agency for Habitat (Afghanistan)
Chair: Champa Patel, Director, Asia-Pacific Programme, Chatham House

Wolfgang Dahmen, Felix Gruber and Olga Mula
Math. Comp. 89 (2020), 1605-1646.
Abstract, references and article information

(University of Barcelona) The yellow-legged gull has a high ability to adapt to human activities and benefit from these as a food resource during all year. This is stated in a scientific article published in the journal Ecology and Evolution whose first author is the researcher Francisco Ramírez, from the Faculty of Biology and the Biodiversity Research Institute (IRBio) of the University of Barcelona.

(Clemson University) While the world admires the beauty and fragrance of flowers, most of us are missing out on the extraordinary processes these seemingly delicate life forms are carrying out every moment of the day. Matthew Koski, an assistant professor at Clemson, is not only paying attention, he is advancing his research with a three-year, $455,000 grant from the NSF for a study of flower adaptations titled 'Modifying the floral microenvironment: elevational divergence in floral thermoregulatory mechanisms.'

Back in January when dancehall artiste Govana released the track HAMANTS Convo, the storyline captivated listeners across the globe. For weeks, the song, which highlights infidelity in relationships, trended at number one on the local YouTube...

Quentin Perraud
Apr 1, 2020; 19:589-607
Research

James A. Wilkins
Apr 13, 2020; 0:RA120.001944v1-mcp.RA120.001944
Research

Yan Zhou Tran
Mar 31, 2020; 0:RA120.002036v1-mcp.RA120.002036
Research

Taewook Kang
Apr 7, 2020; 0:RA119.001882v1-mcp.RA119.001882
Research

Eva Griesser
May 1, 2020; 19:839-851
Research

Payman Samavarchi-Tehrani
May 1, 2020; 19:757-773
Review

Invitation Only Research Event

Bacteria secrete siderophores to access iron, a key nutrient poorly bioavailable and the source of strong competition between microorganisms in most biotopes. Many bacteria also use siderophores produced by other microorganisms (exosiderophores) in a piracy strategy. Pseudomonas aeruginosa, an opportunistic pathogen, produces two siderophores, pyoverdine and pyochelin, and is also able to use a panel of exosiderophores. We first investigated expression of the various iron-uptake pathways of P. aeruginosa in three different growth media using proteomic and RT-qPCR approaches and observed three different phenotypic patterns, indicating complex phenotypic plasticity in the expression of the various iron-uptake pathways. We then investigated the phenotypic plasticity of iron-uptake pathway expression in the presence of various exosiderophores (present individually or as a mixture) under planktonic growth conditions, as well as in an epithelial cell infection assay. In all growth conditions tested, catechol-type exosiderophores were clearly more efficient in inducing the expression of their corresponding transporters than the others, showing that bacteria opt for the use of catechol siderophores to access iron when they are present in the environment. In parallel, expression of the proteins of the pyochelin pathway was significantly repressed under most conditions tested, as well as that of proteins of the pyoverdine pathway, but to a lesser extent. There was no effect on the expression of the heme and ferrous uptake pathways. Overall, these data provide precise insights on how P. aeruginosa adjusts the expression of its various iron-uptake pathways (phenotypic plasticity and switching) to match varying levels of iron and competition.

Systemic infection and proliferation of intracellular pathogens require the biogenesis of a growth-stimulating compartment. The gastrointestinal pathogen Salmonella enterica commonly forms highly dynamic and extensive tubular membrane compartments built from Salmonella-modified membranes (SMMs) in diverse host cells. Although the general mechanism involved in the formation of replication-permissive compartments of S. enterica is well researched, much less is known regarding specific adaptations to different host cell types. Using an affinity-based proteome approach, we explored the composition of SMMs in murine macrophages. The systematic characterization provides a broader landscape of host players to the maturation of Salmonella-containing compartments and reveals core host elements targeted by Salmonella in macrophages as well as epithelial cells. However, we also identified subtle host specific adaptations. Some of these observations, such as the differential involvement of the COPII system, Rab GTPases 2A, 8B, 11 and ER transport proteins Sec61 and Sec22B may explain cell line-dependent variations in the pathophysiology of Salmonella infections. In summary, our system-wide approach demonstrates a hitherto underappreciated impact of the host cell type in the formation of intracellular compartments by Salmonella.

Laser-capture microdissection (LCM) allows the visualization and isolation of morphologically distinct subpopulations of cells from heterogeneous tissue specimens. In combination with formalin-fixed and paraffin-embedded (FFPE) tissue it provides a powerful tool for retrospective and clinically relevant studies of tissue proteins in a healthy and diseased context. We first optimized the protocol for efficient LCM analysis of FFPE tissue specimens. The use of SDS containing extraction buffer in combination with the single-pot solid-phase-enhanced sample preparation (SP3) digest method gave the best results regarding protein yield and protein/peptide identifications. Microdissected FFPE human substantia nigra tissue samples (~3,000 cells) were then analyzed, using tandem mass tag (TMT) labeling and LC-MS/MS, resulting in the quantification of >5,600 protein groups. Nigral proteins were classified and analyzed by abundance, showing an enrichment of extracellular exosome and neuron-specific gene ontology (GO) terms among the higher abundance proteins. Comparison of microdissected samples with intact tissue sections, using a label-free shotgun approach, revealed an enrichment of neuronal cell type markers, such as tyrosine hydroxylase and alpha-synuclein, as well as proteins annotated with neuron-specific GO terms. Overall, this study provides a detailed protocol for laser-capture proteomics using FFPE tissue and demonstrates the efficiency of LCM analysis of distinct cell subpopulations for proteomic analysis using low sample amounts.

The study of protein subcellular distribution, their assembly into complexes and the set of proteins with which they interact with is essential to our understanding of fundamental biological processes. Complementary to traditional assays, proximity-dependent biotinylation (PDB) approaches coupled with mass spectrometry (such as BioID or APEX) have emerged as powerful techniques to study proximal protein interactions and the subcellular proteome in the context of living cells and organisms. Since their introduction in 2012, PDB approaches have been used in an increasing number of studies and the enzymes themselves have been subjected to intensive optimization. How these enzymes have been optimized and considerations for their use in proteomics experiments are important questions. Here, we review the structural diversity and mechanisms of the two main classes of PDB enzymes: the biotin protein ligases (BioID) and the peroxidases (APEX). We describe the engineering of these enzymes for PDB and review emerging applications, including the development of PDB for coincidence detection (split-PDB). Lastly, we briefly review enzyme selection and experimental design guidelines and reflect on the labeling chemistries and their implication for data interpretation.

Host Matt Egan is joined by producer Chris to talk about the raft of announcements coming out of the Google I/O developer conference this week, including Android N, Google assistant and Allo. Techworld.com editor Charlotte Jee joins in to discuss driverless cars (17:00) following the Queen's speech this week. Finally, acting editor at Macworld.co.uk David Price talks about terrible film adaptations of video games, from Angry Birds to World of Warcraft (29:00). Don't forget to like, share and tell your friends!  

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