Monthly Archives: February 2022

Nature is analogue. It is not a binary system. In the living world there are no explicit switches that discreetly turn systems on or off. Rather, nature adjusts systems through analogue dials, like an old radio gradually changing variables to achieve balance and equilibrium to ensure that life is sustainable and carries on.

Evolution proceeds in this way, with new life forms appearing and some disappearing over millennia or, in the case of microbial pathogens (viruses, bacteria and parasites) over days or weeks.

Evolutionary change results from two opposing forces: Positive selection reproduces beneficial genetic variations that enable the virus to survive, while negative selection pressure hinders the viruss survival and ability to reproduce.

Evolution can be studied at the molecular level. For many years, my research was focused on the African trypanosome, the parasite responsible for African sleeping sickness.

Trypanosomes live in the bloodstream of its mammalian hosts (including humans) and early observations of their numbers showed a consistent wave-like pattern of increases followed by declining numbers and then, after a week or so, rising numbers again.

Trypanosomes are vulnerable to the antibodies produced by their hosts immune system, which bind to the parasite and eliminate it. This immune response causes the trypanosome numbers to drop, as illustrated by the low points of the wave pattern. But before the trypanosomes disappear entirely, their numbers rise again and the wave repeats.

This intriguing growth pattern generated much interest and research in my laboratory and, ultimately, we learned that the parasite can alter its molecular identity to evade the hosts antibodies before it is completely eliminated. This means that the population of trypanosomes responsible for each of the wave peaks is a variant distinct from all the others. Antibodies directed against one variant have no effect on subsequent variants, so the wave pattern continues.

The trypanosomes very successful strategy evolved to help it survive in the face of constant negative selection pressure from antibodies. This mechanism that helps a parasite or pathogen evade the hosts immune system is called antigenic variation.

I am reminded of the growth curve of trypanosomes when looking at the pattern of Canadian case counts from the ongoing COVID-19 pandemic.

The peaks in cases reflect the arrival of new variants, the most recent of which is omicron, the variant now circulating most widely globally.

The strategy used by SARS-CoV-2, the virus that causes COVID-19, is similar to the trypanosomes, although the mechanism for generating novel variants is quite different. For the virus, new variants arise by mutation in genes that encode the so-called spike protein, the part of the virus that enables it to enter cells and infect people.

Mutations arise due to errors that occur when the virus is replicating itself in the cells of the hosts respiratory system. Because the virus has a mechanism that can attempt to repair the errors, SARS-CoV-2 evolves more slowly than the trypanosome. It evolves more slowly because the virus has a mechanism that can try to repair the errors. However, this repair process is not perfect, and some mutations get retained.

If mutations result in a spike protein distinct from any other variant preceding it, we will see a new variant appearing. The omicron variant is particularly interesting (and somewhat ominous) because of its high number of mutations, not only in the spike protein but in other viral genes as well.

By employing this strategy of antigenic variation, the survival of the SARS-CoV-2 virus is assured. So, the appearance of new variants is due to mutations that represent the positive selection force: genetic variations that help the organism get reproduced.

The decline of case numbers during a pandemic is due to negative selection forces. These include effective public health interventions that limit the spread from one person to the next (such as masks), as well as the hosts immune response (antibodies) resulting from either infection, vaccination or both.

An infected person will, over time, generate antibodies against the virus and begin to eliminate that variant, like in the trypanosome case. But because SARS-CoV-2 mutations occur slowly, the virus needs to find a new, non-immune person to carry on. In order to find new non-immune hosts, the virus induces symptoms that help it to spread: the coughing and sneezing that enable it to jump from one person to the next via droplets.

Given the capacity of SARS-CoV-2 to mutate, there are certainly new variants arising continuously. However, if medical and public health interventions are successful in reducing transmission between infected and uninfected/unvaccinated people, it is quite possible that the virus will evolve to generate a less virulent variant that could establish itself as an endemic infection producing mild symptoms.

When people infected with a pathogenic microbe experience symptoms of illness, those symptoms often serve a purpose: they can contribute to either the microbes survival or the survival of the infected host. A classic case is diarrhea resulting from infection with cholera or from amoebic dysentery. Both infections produce life-threatening diarrhea, but the symptom serves different purposes in each disease.

In the case of cholera, this symptom serves the microbe because it enables the bacteria to exit the hosts body and, in places with poor sanitation, contaminate the water supply and transmit to new hosts. In the case of amoebic dysentery, the symptom is a result of the hosts body attempting to rid itself of the infection.

Clinicians must be able to distinguish between these two scenarios in the management of infectious diseases in order to avoid contributing to the problem rather than solving it. In the case of COVID-19, clinical symptoms like sneezing and coughing that enable the virus to spread through the air are positively selecting variants that help the virus spread to new, susceptible individuals (such as unvaccinated people).

That means measures like masking, social distancing and vaccination can impede spread by helping to prevent aerosol transmission.

Continued efforts to achieve a fully vaccinated population are crucial. The unvaccinated and the uninfected are ideal hosts for SARS-CoV-2, and ideal for generating new variants due to the absence of negative selection by antibodies, which makes it easier for the virus to replicate and produce new mutations.

Although nature may move slowly in an analogue manner, humans can flip binary switches and we can act now to ensure global vaccine equity. Ensuring global vaccine coverage is not only imperative from an evolutionary perspective but is clearly the ethical option as well.

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How new COVID-19 variants emerge: Natural selection and the evolution of SARS-CoV-2 - The Conversation CA

Rebecca Hollister

I once had a bad habit of making broad statements about things I would never do. For example, I said that I would never have a roommate past freshman year of college, never attend a non-Ivy League school and never return to Leavenworth as an adult.

One promise I was also determined to keep was never living in what was known at Georgetown as Village A. Vil A, as we called it, was a massive sprawl of upperclassmen apartments, filled with heavy bass and raucous laughter at least four nights per week. However, housing selected Vil A for me and my roommates past freshman year, so I had to say goodbye to another of my past declarations.

Once I lightened up a bit, became less rigid, my whole world brightened. Though I did not always appreciate the constant noise, I felt like a true college student when I worried my ceiling would cave in due to parties on the second floor. I grew quite fond of Vil A, despite the constant smell of alcohol.

In March of that junior year, my life turned upside down. Georgetown informed everyone that students had to officially move out within two weeks, due to coronavirus. Unlike most of my friends who had gone home for spring break and wouldnt be back, I returned to campus from a trip to England, cut short by pandemic worries. As I rolled my suitcase up the stairs to campus, I had the now persistent feeling that something was wrong. I pinpointed it when I unlocked my door. Vil A was dead silent.

Even though students were gone for spring break, there were usually a select few that remained to party. On this night, I finally got the peace that I wanted. And I hated it.

The next five days were filled with chaos and the unknown. Mountains of stuff were thrust out of dorms; no one locked their doors. I said goodbye to a few acquaintances. One of my transgender friends sobbed, terrified to go home to unloving parents for an undetermined amount of time. My international friends worried about getting home safely and risks of exposure along the way. I gave the rest of my food and some furniture to those staying nearby, wishing them luck.

The universe was now making large declarations of things I would never do. I did not know that I would never step foot in many buildings on campus again, or attend temple services, or greet library patrons at my job. If I could go back to

If I could go back to those five days, I would run through each building, taking in the sounds and sights of students laughing, maskless. Part of why I had to break so many of my past self-promises was that my life changed so many times. I am constantly changing to this day.

The moment I finally stepped off the plane at the Kansas City airport, into the arms of my mother, I decided officially to clean my own slate. No more promises. I would let the universe guide me. I would never attend the same Georgetown again, but that was OK. I had grown, but Georgetown had stayed the same. It was now time to ask Leavenworth to grow along with me. Rebecca Hollister is

Rebecca Hollister is a Leavenworth Times columnist.

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A personal evolution and a return to Leavenworth - Leavenworth Times

SHRM certification is designed to reflect the HR competencies that are most relevant in today's world. The documents and exams that make up the program are continually enhanced and revised. To accomplish this, SHRM conducts a practice analysis every few yearsa thorough, systematic research study of the professionto ensure that SHRM certification remains current with trends in HR and events throughout the world of work.

This two-part article discusses the results of SHRM's most recent practice analyses and the changes based on these research efforts that will go into effect in May 2022.

Last month, Part I discussed updates to the SHRM Body of Applied Skills and Knowledge (SHRM BASK) and to eligibility requirements for candidates seeking to take the SHRM-CP and SHRM-SCP exams. Part II, below, discusses the research that drove modifications to the length and timing of the exams themselves.

Need for Adjustments to Exam Length and Timing

Feedback from people who took the SHRM certification exams showed a need for two kinds of adjustments: to the length of the exam (i.e., number of questions asked) and to the time limit (i.e., number of minutes allotted to answer the questions and finish the exam).

In the exam development field, the term used for the number of questions that have to be answered correctly for a test-taker to pass the exam is the "standard" or "cut score." Test-takers who do not meet the standard or cut score fail the exam. "Speededness" is the term used to describe the extent to which the time limit for an exam alters a test-taker's performance by needing to rush to finish.

In response to examinees' feedback, SHRM set out to determine whether and how to make and optimize adjustments to exam length and speededness. Once any adjustments were made, we would determine how the exams would be affected in terms of their reliability, validity, pass rates and scoring accuracy.

The goal was to preserve the reliability and validity of each SHRM certification exam, while giving most examinees sufficient opportunity to answer all the questions within the allotted time and without rushing to finish.

External research studies were conducted on exam length, speededness, accuracy of scoring and pass rates.

Number of Scored Questions

SHRM's current certification exams have 130 scored questions. Of current test-takers, 80 percent finish the exams with time remaining.

According to the research studies on length and speededness, reducing the number of scored questions to 110 would cause virtually no change in exam reliability or validity. In addition, the percentage of test-takers who finish with time remaining would increase to 90 percent.

Reducing the number of scored questions would also cause no change in the accuracy of scoring and pass rates, according to the research study covering these factors. The exams would continue to be scored accurately. Calculations also showed that with fewer questions, pass rates for both exams would likely go up, with the greatest increase projected for the SHRM-SCP.

Unscored Field-Test Questions

Effective with the May 2022 testing window, there will be 134 questions on each SHRM certification exam. Of these items, 110 questions will be scored and 24 questions will be unscored or "field-tested." The field-testing process, by which we regularly add and remove exam questions, helps us keep the SHRM-CP and SHRM-SCP exams fair and up-to-date.

Before new questions are officially added to an exam, they are tried out "in the field." Several field-test items are mixed into the exams during each window, but the test-takers' answers to these questions will not "count" toward their final scores. Because examinees don't know which questions are whichscored or unscoredit is crucial to answer all of them.

After the testing window closes, we analyze the performance of the field-test items. Following several review cycles, the items that meet our performance standards become operational as scored questions on subsequent exams.

Of the 134 questions that will be on the next SHRM certification exam, 110 questions will be used to calculate the examinee's score. The 24 field-test items won't be part of that calculation. In the long run, however, those items will play an important part in SHRM's ongoing development of future exams.

Amount of Time to Take the Exam

Effective May 2022, the total testing time for each SHRM certification exam is three hours and 40 minutes, divided into two equal sections of 110 minutes. Our research showed that 90 percent of test-takers will finish both sections within the time allotted, and likely with time remaining in each section.

The original time limit for the exams was four hours, but the new shorter time is optimal according to the speededness study (see above).

Examinees must complete the first section of the exam and clear any flagged or unanswered questions before proceeding to the second section. Each section must be completed independently; examinees cannot move from one to the other. The clock runs continuously during each section, including while a test-taker might take an unscheduled 15-minute break.

Therefore, SHRM recommends that examinees who complete the first section of their exam with any time remaining should take their unscheduled break before moving on to the second section.

Two Types of Exam Questions

The SHRM-CP and SHRM-SCP exams are based on the information described in the SHRM BASK, which consists of nine behavioral competencies and one technical competency, HR Expertise, which is divided into 14 HR functional areas.

Both certification exams feature two types of questions: 1) knowledge items, which assess candidates' knowledge and application of knowledge; and 2) situational judgment items, which assess candidates' problem-solving, behavior and decision-making skills.

The scored questions as well as the unscored field-test questions on the exams include both knowledge items and situational judgment items.

HR-specific knowledge items (KIs) cover the 14 functional areas of the SHRM BASK's technical competency. Foundational knowledge items (FKIs) cover the nine behavioral competencies. Each knowledge item has one correct answer, and candidates will receive credit for selecting it.

Situational judgment items (SJIs) present realistic work-related scenarios, followed by four possible strategies or courses of action to resolve or address the issues raised. All four options may be effective, but candidates will receive credit only for selecting the answer that describes the best or most effective strategy or course of action (as determined by a panel of experienced HR professionals).

In sum, half the questions on each SHRM certification exam cover the HR functional areas (50 percent KIs) and half the questions cover the behavioral competencies (10 percent FKIs plus 40 percent SJIs).

Part I of this article appeared in the Jan. 20, 2022, issue of the Certification Update.

Nancy A. Woolever, MAIS, SHRM-SCP, is vice president of certification at SHRM.

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The Evolution of SHRM Certification: Part IIChanges to Exams - SHRM

Increased crop yield is no longer the measure of a successful farmer. Nowadays, the yardstick is profitability, and that probably wont come from dragging iron through the soil.

The Farming Evolution symposium returned to an in-person event in Holyoke this year, and its a popular as ever. The two-day workshop on soil health attracted more than 150 attendees this year. Its being held Wednesday and Thursday in the Phillips County Event Center in Holyoke.

The theme of this years workshops is profitability; it doesnt do any good to increase crop yields if it costs too much for inputs like seed, fertilizer and fuel. Hays, Kan., farmer Brice Custer, told the group Wednesday that two principles long held sacred by modern farmers arent necessarily good for them.

Farming for top yield is not necessarily profitable, Custer said. If it costs more than it returns, that high yield isnt the right goal. If you get a lower yield at a much lower cost, youre going to come out money ahead.

In a presentation titled How Not to Loser Youre A$$ Farming, Custer showed two scenarios based on real-life experiences of those attending. In a traditional farming operation, attendees estimated costs of wheat farming at about $300 per acre for a yield of about 60 bushels per acre. All agreed that higher yields were possible but only at higher costs. In the second scenario, using no-till practices and cover cropping, inputs for the wheat crop were estimated at about $150 per acre for a yield of about 50 bushels per acre. At a price of $7 per bushel for wheat, the difference was roughly $45 per acre.

Dropping the price of the wheat, according to Custers scenario, cut much deeper into profits on the traditional farm than on the no-till farm.

The other dearly-held principle that turns out to be a money loser is fallowing fields. Letting a field lie fallow one year in three had been thought to allow the soil to rest, but Custer said the fallacy is that the fallow field returns nothing and doesnt really regenerate microbials by lying vacant. Instead, Custer said, putting in a cover crop that actually does increase microbial soil health offers the opportunity to graze livestock or harvest and sell yet another crop while improving the aggregate quality of the soil.

Custer advised audience members that converting to no-till and cover cropping isnt a taking the plunge endeavor, but requires moving into it a little at a time.

You have to do whats best for you, he said. Dont do it all at once, but do some experimenting, get your soil tested, get some advice from people who are doing it.

Earlier in the day Candy Thomas demonstrated the difference between intensively tilled soil and no-till soil with a cover crop. Using a miniature wind machine she showed how easily the daily breezes of the High Plains can erode bare topsoil. She also put water through various types of soil to show how an aggregate soil will hold up but a dirt clod will break down and shed water.

Thomas, who is the regional soil health specialist for the Natural Resources Conservation Service in Salina, Kan., said the tests she ran can be conducted for a few dollars on the tailgate of a pickup. Thomas region covers Colorado, Iowa, Illinois, Kansas, Missouri and Nebraska.

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Profitability is the byword at 2022 Farming Evolution workshops - Journal Advocate

MarTechs daily brief features daily insights, news, tips, and essential bits of wisdom for todays digital marketer. If you would like to read this before the rest of the internet does, sign up here to get it delivered to your inbox daily.

Good morning, Marketers, what can we learn about the evolution of digital experience platforms, aka DXPs?

Because I report on technology news, the love of language that brought me to writing collides with the evolution of succinctly, and at times oddly, named tools. Alphabet soup was actually my favorite as a kid, and now I get a new bowl with every adtech and privacy story I file.

DX is an evolution of CX, and I dont think its an accident that DXPs largely came out of CMSs. To me, it means that content is still very important when engaging with customers online. CX is a more rapid conversation today across so many touchpoints and I think content should be thought of as part of that conversation, and in ways a culmination or summary of that conversation.

A good ad or a relevant email message, or even a white paper, should let a customer know that youve been listening to what theyve been telling you.

Chris Wood,

Editor

P.S. Free registration for the spring MarTech conference is now open.

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Good morning: The evolution of digital experience - MarTech

Earth is crawling with lizards and snakes. More than 10,000 species of these reptiles, called squamates, have adapted to thrive across almost every continent. But this vast assortment took a surprisingly long time to develop, according to University of Bristol paleontologist Jorge Herrera-Flores and his colleagues. Instead of trying new adaptations as quickly as possible, squamates succeeded by evolving with a relatively slow and steady pace, the researchers sayan idea counter to many biologists assumptions about how and why life generates diversity.

The researchers charted squamates evolution in a new study published in Palaeontology, contrasting them with elusive reptilian relatives called rhynchocephalians. Today the latter are represented by just one living speciesNew Zealands tuatarabut there were far more in the deep past. For many decades, Herrera-Flores says, it has been questioned what was the real cause of the decline of the rhynchocephalians.

The researchers observed a strange pattern: the two groups evolutionary trajectories were flipped. Squamates evolved differences in body size slowly during the first two thirds of the groups existence, from about 240 million to 80 million years ago. At the same time, rhynchocephalians were rapidly splitting into a profusion of different sizesuntil their diversity collapsed.

Until now, it had seemed that quick bursts of evolutionary experimentation built long-term staying power. Previous studies of two other reptile groups, dinosaurs and crocodiles, proposed that fast early evolution helped these animals shoulder out competitors and quickly dominate the landscape. By that logic, rhynchocephalians speedy variations should have presaged greater success. Instead, Herrera-Flores and his colleagues suggest, fast evolution might create a kind of volatility that leads more readily to extinction. Squamates slower pace resulted in a more stable history, followed by a later burst of diversity when tuatara relatives were already on their downturn.

Reptiles are not alone in this apparent slow and steady strategy. Even though modern bony fishes are much more diverse today, a previous study found that in the past they were not as numerous or varied as holosteansthe prehistoric relatives of todays gar and paddlefish. Such studies suggest that quickly diversifying to fill more niches is not always a route to long-term success.

And unlike its cousins, the specific rhynchocephalian lineage that led to todays tuatara had exceptionally low rates of evolution, notes Harvard University herpetologist Tiago Simes, who was not involved in the new study. This is what makes the tuatara stand out as a living fossil, an echo of an ancient evolutionary boom that eventually went bust.

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Snakes' and Lizards' Slow and Steady Evolution Won the Race - Scientific American