14 July 2017

Traffic Stop Racial Disparities

Welcome back. I came across a recent study that was sort of a good news, bad news report on racial relations in the US.

Oops...side-view mirror image of
a traffic stop. (multiple websites)
Seeking to improve community relations, the Police Department of Oakland, California, cooperated with a team of Stanford University researchers on an analysis of language transcribed from body-camera video of traffic stops. 

The investigation found words uttered by police officers, though respectful to everyone, were significantly more respectful to whites than to blacks.

Body-Camera Video Transcriptions
The researchers used transcriptions of 183 hours of body-camera video from 981 routine traffic stops of black (682) and white (299) drivers made by 245 different police officers during April 2014. In all, they obtained 36,738 officer utterances for analysis.

The investigation was completed in three steps, which the researchers labeled three separate studies.

Study 1: Human Ratings of Officer Utterances
To test whether human raters could reliably judge differences in respect from transcriptions of officers’ language, the researchers randomly sampled 312 utterances spoken to blacks and 102 utterances spoken to whites.

They enlisted 70 participants (39 female, average age 25) to each rate 60 of the 414 utterances on five overlapping dimensions: how respectful, polite, friendly, formal and impartial the officer was in each exchange. Participants read the officer’s utterance together with the immediately preceding driver’s utterance if there was one.

Each of the 414 utterances was rated by at least 10 participants, and the scores were averaged to calculate a single rating on each dimension. The five dimension ratings were then combined statistically.

Study 1 determined that human raters could reliably glean key features of police officer treatment from their language. The results showed officers’ utterances toward black drivers rated lower than utterances toward white drivers on every dimension.

Study 2: Developing Computational Models
To extend the value of study 1 toward a more general solution for analyzing body-camera language, the researchers developed computational linguistic models of respect and formality.

The models were based on theories of politeness, power and social distance in respectful language, for example, apologizing (sorry for stopping you), softening of commands, saying thank you and using formal (sir, ma’am) instead of informal titles. The utterances from study 1 were used to tune the models.

Study 2 determined that the model-derived ratings agreed with the human ratings from study 1 about as well as human ratings agreed with each other.

Study 3: Assessing Racial Disparities in Respect

Having determined that humans can reliably rate officer speech and that the same ratings can be reliably modeled, the researchers applied the models to the full dataset of 36,738 utterances from the transcribed interactions.

The results showed strong evidence that utterances spoken to whites were consistently more respectful, even after controlling for contextual factors of the interaction, such as the severity of the offense or outcome of the stop.

Wrap Up
The bad news, of course, is that racial disparities in showing respect haven’t gone away. But the good news is that, not only did the Oakland Police Department cooperate in the study, it began implementing new training programs with the earliest results in 2014.

More good news is that models and methodology from the study can be applied elsewhere as well as to gauge the effectiveness of interventions other than traffic stops.

The work demonstrated the value of body camera video transcriptions as an important source of data to address the limitations of methodologies that rely on citizens’ recollection or direct observation. The computational linguistic models of transcribed datasets have the potential to allow useful information to be extracted while maintaining objectivity and privacy and ultimately improve police-community relations.

Thanks for stopping by.

Stanford study of body camera videos in Proceedings of the National Academy of Sciences: www.pnas.org/content/early/2017/05/30/1702413114.full
Example media reports on Stanford study:

07 July 2017

A Horse’s Tail

Welcome back. Maybe you remember. A couple of years ago, I blogged that my wife Vicki, like many or most people who have owned or raised or been close to horses, can usually tell from a horse’s actions and facial expressions if the horse is happy, sad, tired, hurting or the like (Horse Facial Expressions).

I didn’t know if all horses exhibited the same expressions or if Vicki and the other horse readers would concur on their interpretations of those expressions, but there was a new systematic way to describe a horse’s facial expressions, the Equine Facial Action Coding System (EquiFACS), which was the subject of that blog post.

In that post, I also confessed--confessed is probably too strong--I know little about horses. I’ve only ridden one a few times in my life, and the last time was 35 years ago--a 10-minute trot in northwestern China.

You, of course, wonder where this is going.

Enter the Horses
Well, the folks who are renting the barn and pasture to raise beef cattle and formerly chickens and a goat that hung out in the cattle trough (see Roosters’ Crowing) occasionally bring in two horses to graze. One of the horses, Suzie (or maybe Susie), was here last year, and we communicated a bit when I passed by on my afternoon stroll. This year, Suzie has been standing away from the road, enjoying the company of the other horse, which I haven’t met. Vicki said her name is Misty.

Suzie (L) and circular-tail-swinging Misty.
I see the horses when I walk by, and I can sometimes see them through the trees and brush from one of our apartment windows, though that gets harder to do as the vegetation thickens with the season.

Tail Swishing
Here’s the thing. Misty is always swishing her tail. Always. What caught my untrained eye is that it’s not just any side-to-side swish. Misty often swishes her tail in a full 360-degree circle! (I’m pretty sure that deserves an exclamation point.) I had to know what swishing a tail in a circle meant.

I didn’t conduct a comprehensive review of equine literature or interview veterinarians, horse handlers, horse whisperers or even equestrians; but what I learned is enough for this eclectic blog.

A horse’s tail is thought to serve three purposes:
-Swat flying insects.
-Keep warm. If cold, a horse uses its tail to prevent heat loss from the area under the tail, and it may bring its tail all the way between its legs to cover more.
-Communicate through body language.

A horse’s body language can get quite involved. I’ll limit myself to tail swishing, which is involved enough, for it can relate to the horse’s physical, mental or emotional state, or to any combination thereof.

The consensus is that a horse swishes its tail when it’s agitated, uncomfortable, in pain or out of balance or a rider is out of balance. It’s possible the horse is not enjoying the training or the exercises are stretching its comfort zone. It could be that the horse is confused trying to learn something new or that it’s simply concentrating.

A mare swishing her tail near a stallion might be attributed to the mare being--or not being--in heat.

And, yes, the horse may be swishing its tail to express pleasure or contentment.

Wrap Up
There are many reasons why a horse might swish its tail. While excessive or violent swishing is likely a signal to stand back, the context must be considered. If I consider the context, I think it’s clear that Misty is absolutely thrilled to be with Suzie, who’s much more interested in Misty than in saying hello to me.

Now, as to why Misty swishes her tail in a circle, I haven’t the foggiest idea. I’ve blogged how the lack of symmetry in dog tail wagging was linked to the left and right sides of the brain (Dog Tail Wagging)
, but that’s left and right, not circular. If you have some thoughts on it being more than just because, please share them with me, the horse tail watcher. Thanks for stopping by.

Principal references:

30 June 2017

Emergency Room Overcharges

And while we’re on the topic of healthcare… 
Heading to the ER.
(multiple websites)
Welcome back. Four years ago, I ended up in the emergency room. My medical problem wasn’t life-threatening, though we didn’t know that before I got there. Since the emergency department charges were new and different, I had no way of knowing if they were out of line with my usual internal medicine charges from the same medical facility.

I bring up this price comparison because that was the focus of a recent nationwide study from Johns Hopkins University. The researchers found emergency department charges were not only higher but that uninsured patients were often billed the chargemaster prices.

Like most people outside of the medical profession and possibly many within it, I first learned about chargemaster (aka charge master) from Steven Brill’s article in a 2013 issue of TIME magazine.

Every hospital has its own chargemaster, which is a comprehensive list of items and prices--from supplies to pharmaceuticals to procedures--that the hospital can bill patients or insurance. The prices serve as a starting or anchoring point for negotiations and tend to be high, well above the hospital’s actual cost.

According to a 2016 Pepperdine Law Review paper by George Nation III, professor of law and business at Lehigh University, hospital administrators frequently argue that the high prices don’t matter because no one really pays chargemaster prices. Nation refutes that, pointing out that chargemaster prices constantly increase, creating upward pressure on pricing throughout the healthcare marketplace. He also notes that many hospitals refuse to reduce their chargemaster prices for self-pay patients.

Hospital charges are variable and, for the uninsured, especially high. (Graphic from www.linkedin.com/pulse/understanding-hospital-charges-costs-payments-tom-williams)

ER Charge Comparison
The Johns Hopkins University researchers analyzed Medicare billing records from the year 2013. The records were for 12,337 emergency medicine physicians from 2707 hospitals and 57,607 internal medicine physicians from 3669 hospitals in all 50 states.

They determined the markup ratios of how much hospital departments billed for services divided by the Medicare allowable amount, which includes the deductible and coinsurance, what Medicare pays and the amount the patient or other third party pays. If, for example, the Medicare allowable amount was $100 and the hospital charged $200 or 100% above the allowable amount, the markup would be $200/$100 or 2.0.

The markup ratios for emergency departments varied from 1.0 to 12.6 and averaged 4.4 or 340% above the Medicare allowable amount. The markup ratios for internal medicine departments varied from 1.0 to 14.1 and averaged 2.1 or 110% above the Medicare allowable amount.

The highest emergency department markups were associated with for-profit hospitals. Based on census records, the highest markups were likely charged to minorities and uninsured patients.

Wrap Up
The researchers showed that, across hospitals, there was wide variation in excess charges for emergency department services, which were often priced higher than internal medicine services for the same services.

They call for legislation to protect uninsured as well as out-of-network patients, noting that several states have passed some legislation to protect uninsured patients from paying chargemaster prices.

Perhaps it will all be addressed by the new and improved Trumpcare. Thanks for stopping by.

Steven Brill’s article on medical billing in TIME: healthland.time.com/2013/02/20/bitter-pill-why-medical-bills-are-killing-us/print/[2/26/2013
George Nation III’s paper on chargemaster in Pepperdine Law Review: pepperdinelawreview.com/wp-content/uploads/2016/04/Nation%E2%80%93Final-No-ICR-2.pdf
Johns Hopkins study of emergency department charges in JAMA Internal Medicine: jamanetwork.com/journals/jamainternalmedicine/article-abstract/2629494
Article on Johns Hopkins study on ScienceDaily website: www.sciencedaily.com/releases/2017/05/170530115045.htm

23 June 2017

Goats in Trees

What? Goats again? Yeah, I know. I just blogged about goats a few months ago (Looking at Goats). But there was a recent study that gave me the opportunity--ok, excuse--to write about goats that climb trees! 
Goats in argan tree, Morocco.
(multiple websites)

Welcome back. I hope you won’t rush off if I hold on the goats and begin with the trees the goats climb. They’re central to this story.

Argan Trees
Although argan trees (Argania spinosa) are found in Algeria and have been introduced elsewhere, the tree is largely confined to a UNESCO-designated biosphere reserve of some 3000 square miles in the semidesert Sous region of southwestern Morocco.

Argan trees are long-lived (150-200 years), evergreen, thorny, reach a height of 30 feet, sometimes more, and have sturdy, knotty trunks, wide-spreading crowns and long, deep roots to survive the arid environment. The leaves are small, clustered and lanceolate; the flowers are small and greenish-yellow.

Argan tree fruit.
(multiple websites)
And then there’s the fruit. The ovoid fleshy drupes are similar to olives, though larger and rounder, with thick peels covering the pericarp and a hard-shelled nut, which contains up to three small, oil-rich seeds. That oil is used for culinary and cosmetic purposes and has become a high-value product for export. In the U.S., for example, the number of personal-care products with argan oil increased from two in 2007 to over one hundred by 2011. 

Dried argan tree fruit, nut inside fruit and seed inside nut. (multiple websites)

Argan Seed Dispersal
Which brings me back to the goats and the research study. When other available forage is lacking in autumn, these domestic goats may climb the argan trees to dine on the leaves and fruit after the fallen fruit is depleted. Goat herders may even assist kid goats new to climbing trees.

One benefit to the tree species of having goats consume the fruit is that the goats will disperse the seeds away from tree and thus give the seeds and seedlings a higher probability of survival. Endozoochory, the dispersal of seeds (or spores) via ingestion and passage through the digestive system, is the popular notion of how the argan seeds are spread.

Researchers from the Spanish National Research Council’s DoƱana Biological Station were skeptical that endozoochory was the dominant argan seed-dispersal process because goats seldom defecate large seeds. The scientists postulated that the goats, which are ruminants, were regurgitating when chewing their cud and spitting out at least the larger seeds.

To demonstrate that goats could be spitting viable seeds from their cud, the researchers fed fruits of different size and structure, including five drupes or pomes and one legume, to Spanish goats. They were able to recover appreciable numbers of regurgitated seeds, though not all since the goats were not under controlled conditions.

As expected, they found that almost any seed could be ejected during chewing, spat from the cud, digested or defecated; however, the larger seeds, comparable to those of argan, were more frequently spat out during rumination. The researchers also confirmed that over 70% of the regurgitated seeds were viable.

More goats in an argan tree,
Morocco. (multiple websites)
Wrap Up
Establishing that goats spit viable seeds from cud has broad ecological importance if it is common among ruminants. Studies of ruminants as seed dispersers based exclusively on dung analyses may have underestimated a large fraction of dispersed seeds, especially seeds from plant species with fruit and seed traits, such as size, that differ from those of plant species dispersed through defecation.

And you probably thought I chose the topic just because of the goats in trees. Thanks for stopping by.

Natural history note on goat seed dispersal in Frontiers in Ecology and the Environment journal: onlinelibrary.wiley.com/doi/10.1002/fee.1488/full
Article on study on ScienceDaily website. www.sciencedaily.com/releases/2017/05/170524152555.htm
Example video of tree-climbing goats: www.youtube.com/watch?v=z2YKwGtcMY8 (CBS news, 3 minute)
Background on Argan trees and oil: