Gas station without pumps

2022 May 2

Secret Walks: Museum of Natural History

Filed under: Uncategorized — gasstationwithoutpumps @ 11:33
Tags: , , , ,

On Sunday, 1 May 2022, my wife and I walked to the Santa Cruz Museum of Natural History, to see the annual display of scientific illustration.

Museum-of-Natural-History-map

(Click for higher-resolution map) We went down Bay, through Neary Lagoon on the floating boardwalk, along Beach Street, and across the pedestrian bridge. We returned across the Riverside bridge, so that we could go downtown for lunch. The whole walk was about 5.7 miles.

pie-billed-grebe-1

At full zoom, my camera takes rather poor pictures (I haven’t found a way to restrict it to doing only optical, and not digital zoom). But I needed full zoom to identify this bird in Neary Lagoon as a pie-billed grebe.

mallard-on-hand-rail

We’ve never seen a mallard duck standing on a railing before—they usually prefer flat surfaces.

coot-in-sun

We only saw one coot in the lagoon—usually coots seem to hang out in fairly large groups.

pie-billed-grebe-2

Another pie-billed grebe. This one made a very loud call—you can hear a similar call at https://www.allaboutbirds.org/guide/Pied-billed_Grebe

pie-billed-grebe-3

Yet another pie-billed grebe.

yellow-iris

The yellow irises near Neary Lagoon are still blooming, but not as exuberantly as a week or two ago.

buttercups

The buttercups are attracting pollinators. I did not get a close enough photo to decide whether these are bees or hoverflies, but I lean toward hoverflies.

purple-salsify

Purple salsify grows as a weed here. Supposedly the stalks and roots are edible if cooked. We have a little in our back lawn.

red-valerian

Red valerian also grows as weed.

Monarch

Santa Cruz now has a year-round population of monarch butterflies, but no longer seems to get many migrating ones.

carousel-mural

I think that this mural on the carousel building at the Boardwalk is a fairly new one—at least, I don’t remember seeing it before.

liars-beware

On Hiawatha, someone has gotten a bit carried away with decorating their garage with wooden letters. The signs seem to say “liars beware” and “idiocracy wag the dog”.

bee-in-bottlebrush

Photographing bees feeding on bottlebrush bushes is difficult—the bees dive into the flower deep enough that little of them is visible. This was as much of a bee as I ever managed to get.

I did not take any pictures at the museum—it would not be right to take photos of the art work on display. The museum still displays a collection of taxidermy (mostly local animals), a live snake, a working beehive with glass sides, a small touch pool, and some American Indian artifacts (including some nice baskets). The museum is a good one for young kids with an interest in nature, and the illustration exhibit was quite good.

California-buckeye

California buckeye flowers are now blooming. This bloom was on a small plant on the river levee.

Scabiosa-atropurpurea

Another naturalized plant is Scabiosa atropurpurea, though it is a pretty enough flower that no one seems to mind.

Lotus-subbiflorus

This ground cover on the levee is one we were not familiar with—it appears to be Lotus subbiflorus.

gull-gliding

I tried to take pictures of gulls landing or taking off—without much success, as they were so far away that I needed a lot of zoom, and then I could not track them easily.

Bonarpartes-gull

This small gull seems to be a Bonaparte’s gull.

Western-and-Bonapartes-gull

Here are a western gull and a Bonaparte’s gull side by side, for a comparison of sizes.

orange-sticky-monkeyflower

The levee has some sticky monkey-flower planted—probably as part of the effort to restore native plants to the levee.

yellow-sticky-monkeyfower

There is also a yellow sticky monkey-flower.

common-goldeneye-1

I believe that these ducks are common goldeneyes, though it is hard to tell when they have tucked their heads away so that neither the eyes nor the beaks are visible.

common-goldeneye-2

This shot is what convinced me that the ducks were male and female common goldeneyes.

driftwood-tree

Behind the goldeneyes was a driftwood tree.

Canada-geese

Canada gees are a fairly common site on the river or in the ponds.

motion-pacific-mural

This mural is the side of the Motion Pacific dance studio.

spiderman

I rarely visit Pacific south of Laurel, so I had not seen these sculptures before.

King-Kong

This gorilla sculpture was part of the same group as the Spiderman sculpture.

We had lunch at Cruz Kitchen and Taps, which replaces Saturn Cafe. I had a blackened-fish sandwich, which has a good sauce, but the fish itself was flavorless (probably tilapia). My wife had the breakfast tacos, which were probably a better choice. The food was not very exciting, and the traffic noise on Laurel made eating outdoors less pleasant that it could have been. We might eat there again, but it won’t be high on our list of destinations.

curly-willow

On the way home, we noticed that the curly willow that was cut down in front of Emily’s Bakery is beginning to regrow from the stump.

house-finch

On Laurel Street, I saw a small bird at the top of a tree, but could not identify it live. Using the max zoom and then enlarging the picture in Photoshop Elements, I could see that it was a house finch.

2022 April 30

Secret Walks: Climate Action Fair

On Saturday, 23 April 2022, my wife and I walked to the Seymour Center to see what the Climate Action Fair was like.  We decided to take a different route there than returning, taking advantage of what we had learned from the Long-Antonelli Loop.

Seymour-Center-map

Click for high-resolution map. We went down King to the end (red), then over to Swift down to the rail-trail, down Natural Bridges to Delaware, Delaware to the trailer park, and around the pond to the bridge (yellow), then over to UCSC’s coastal campus and to the Seymour Center parking lot (green) where the Fair was held. Our return route went on the paths through the coastal campus, crossing the tracks at Shaffer Road, Mission to Western Drive, then Grandview to Escalona to Anthony to Bay to King and home (blue). The whole walk was about 5.6 miles.

I got a few decent bird and flower photos on the walk:

ash-or-pistachio

These blossoms on a tree on King Street were unfamiliar to us. After searching with Google Lens (using this and another photo of the tree), I think is is either an ash or a pistachio tree.

lupine

There are plenty of lupines blooming around town, but I can’t tell the different species and cultivars apart.

hoverfly-on-fortnight-lily

I was trying to take a picture of the fortnight lily—the hoverfly was an unexpected bonus.

peek-at-Antonelli-Pond

Now that the trees and shrubs have leafed out, we only get peeks at Antonelli Pond from Delaware Ave.

California-poppies

In the park by the pond in the trailer park, California poppies are blooming.

water-lily

So are the water lilies in the pond.

silverweed

We did not recognize this yellow flower, but Google Lens identified it as silverweed.

dark-eyed-junco

In the overflow from the pond down to the beach, we saw a dark-eyed junco bathing. I had a hard time photographing it, because it moved around a lot, dunking itself and shaking the water off.

view-from-bridge

Here is a view of the pocket beach from the Peter Sunzeri Memorial Bridge over the pond.

dolphins-on-mobile-home

One of the mobile homes has these cheerful porpoises decorating the end wall.

Natural-Bridges-low-tide

From Horizon Drive, there is a very good view of Natural Bridges State Beach and the tidepools. The tide seemed unusually low to us.

agave

I can’t resist taking pictures of these agave whenever I pass them.

mast-of-La-Feliz

The mast of the wrecked ship La Feliz is still on display on the edge of the cliff, but I don’t know much longer it will be there—it looks like a good storm could either break the mast or erode the cliff beneath it.

song-sparrow-1

We saw this song sparrow, but could not identify what sort of sparrow it was until I got the zoomed-in pictures off my camera.

song-sparrow-2

Here is another view of the song sparrow.

marine-mammal-skulls

At the Climate Action Fair, the best table was for the Marine Mammal Center, who had some lovely casts of skulls of marine mammals (and a few real skulls, though not in this photo).

marine-mammal-skulls-2

More of the cast skulls, plus a couple of real skulls in front—the white one with a crest is the skull of a male sea lion .

There looked like there were other interesting tables and activities at the Climate Action Fair, but the awful music was way too loud and unrelenting. I’m going deaf and I found the music uncomfortably loud—my wife could not stand to be closer than about a quarter mile from it. Going into the Seymour Center only made the noise worse. Talking to people at the tables was nearly impossible, so we just got arepas from the Pana food truck and went home. If I knew who was responsible for organizing the fair, and if I knew they were planning to do such a fair again, I would tell them to throw away the amplifiers—have acoustic music or no music, so that the other activities had a chance.

yellow-flower

We were unable to identify this yellow flower—we think it is probably a California native planted as part of the restoration of the wetlands, but my photo was not distinctive enough to identify it.

gumweed

This yellow flower seems to be a gumweed, though I’m not sure which one.

great-egret

We consider our walks well-formed if we see an egret—and here was a great egret hunting in the grasslands that (in a normal rain year) would be wetlands.

great-egret-with-gopher

The great egret was successful in its hunt—we think it caught a gopher, but at max zoom I could not hold the camera steady enough (even with the monopod) to get a clear photo of the prey.

little-free-library-homeless-garden

We saw a Little Free Library in the middle of the Homeless Garden, but I only took a photo of it from the road—we did not wish to take books away from the homeless people that the library was clearly intended for.

beschorneria

This grand pink flower stalk is from a Bechorneria. (The leaves are green—those red leaves in front are a different plant.)

bee-on-echium

The bees really love the echium flowers. I think that this was a different echium than Pride of Madeira, but I could be wrong.

tahiti-shaved-ice

As we crossed Highway 1 at Western Drive, we saw a shaved-ice truck parked in the shade, but we did not stop to get anything, as we had the walk light to cross the other way.

leucospermum

The leucospermums are still blooming all over town.

little-free-library

We had not seen this Little Free Library before, but there was nothing in it that we fancied.

Cerinthe

This weird blue and purple flower seems to be a Cerinthe major (also known as honey wort).

2022 April 16

ECG: 2-electrode vs. 3-electrode

Filed under: Circuits course — gasstationwithoutpumps @ 12:23
Tags: , , , ,

In Lower PVC frequency, I said “I did not do direct comparisons of the 2-electrode and 3-electrode configurations—I’ll have to try that sometime soon.” So I did that earlier this week, recording resting ECGs first with a 3-electrode configuration (with the bias electrode on my sternum, halfway between the LA and RA electrodes) and then with a 2-electrode configuration (with the bias wire clipped to the RA electrode).  The 60 Hz noise was slightly higher with the 2-electrode configuration, but after filtering and signal averaging the two recordings were almost identical:

resting-2022-Apr-13

The waveforms after signal averaging were remarkably similar. The PVC burden was also similar (20.1% for the 3-electrode recording and 20.5% for the 2-electrode recording).

bpm-resting-2022-Apr-13

The pulse rate from looking at time between spikes worked well for the resting recordings, but the autocorrelation method failed completely, so I did not plot it. The rapid fluctuation in heart rate within a narrow range is real, not an artifact of the algorithm—the heart beats are not perfectly periodic, and the PVCs may be making them even less periodic. The 2-electrode recording probably started a little after 400 seconds—PteroDAQ only time stamps when the file was saved, not what the t=0s time was. I should probably fix PteroDAQ to change that, recording both.

exercise-2022-Apr-13

I tried recording a session on the exercise bike also. The PVCs are mainly during resting at the beginning of the session and at the end of a recovery at the end of the session—the PVC burden was only 1.4%.

bpm-exercise-2022-Apr-13

For the exercise recording, the noise really disrupted the spike-based pulse detection, but did not interfere as much with the autocorrelation-based pulse detection. My peak pulse rate was about 151.5 bpm, by the autocorrelation measure. I’m not sure whether the sudden changes in pulse rate at 100s (when I started pedaling) and around 556s (about 130s into the recovery time) are real or not—the noise in the recording makes it a little difficult to determine the “correct” pulse rate.

The noise during exercise was not 60Hz noise and seemed to vary with whether I was inhaling or exhaling, so I think that it was probably caused by EMG signals from the pectoral muscles or perhaps the diaphragm. The spike detector was clearly missing a lot of the spikes, but making it more sensitive would probably result in false triggering on the EMG noise. I’m wondering whether putting the electrodes on my back, over the scapulae, would reduce the EMG noise, but placing those electrodes and clipping to them would be difficult without an assistant.

The autocorrelation-based pulse detection seems more reliable when exercising, as my pulse is more periodic and has few PVCs, and the autocorrelation method is less susceptible to aperiodic noise.  The spike-based pulse detection seems more reliable when resting, when the pulse is not as periodic and PVCs disrupt the pattern.

I’m also wondering whether a more strenuous exercise session would raise my pulse rate, or whether I’m getting close to my maximum heart rate.  The standard formula for maximum heart rate by age suggests that this may be close to my maximum, but the exercise does not seem all that strenuous, and a couple of years ago I could routinely push to 170 bpm (though perhaps on a device that was an unreliable reporter—it was built into a treadmill at the gym).  So sometime in the next few weeks I’ll try using a higher power output and seeing where my heartbeat tops out.  I’ll probably need to increase the cadence, rather than the resistance, as I’ve been using about 70rpm and 28Nm to get about 205W.  Raising that to 80rpm or even 90rpm is probably easier than increasing the torque.

2022 April 14

Secret Walks: Wilder Ranch Coastal Loop again

Filed under: Uncategorized — gasstationwithoutpumps @ 22:15
Tags: , , , ,

I posted before about my first time doing the Wilder Ranch Coastal Loop on March 25. On April 10, I did the loop again (in the opposite direction) with a group from the Monterey Bay Stanford Club.  I biked there and back, parking my bicycle on the fence next to the parking kiosk, as there do not seem to be any more planned places to park bicycles. I picked up a map of the park from the parking kiosk. The walk was a very slow and leisurely stroll, with frequent stops to look at the scenery.  The average age of the attendees was probably a bit older than me.

sand-plant-beach

This is either Sand Plant Beach (as the state-park map labels it) or Little Strawberry Beach (as Google Maps labels it). There is a trail down to the beach on each side, to connect up to the Ohlone Bluff Trail, but we did not go down to the beach.

seals-on-beach

The next beach east is off-limits to people, because of the harbor seals hanging out there.

sleeping-seal

The seals look very comfortable when they are sleeping.

two-seals

Another pair of seals. Is the one in back molting?

seal-in-surf

This seal looked very happy to be playing in the waves.

seals-with-pup

The biggest change from my previous visit was the presence of pups—here is one surrounded by adults.

possibly-dead-pup

It looks like some of the pups did not survive.

pup-playing-in-water

Here is another pup, playing in the water.

gull-wading

We did not see many birds on this walk, but I did get one shot of a gull wading.

fern-grotto-1

Unlike my previous walk, most of the group walked down the somewhat steep and wet trail to Fern Grotto Beach. Here is the eponymous fern grotto.

fern-grotto-2

The ferns hanging down from the rocks are quite impressive.

fern-grotto-3

Another view of the ferns.

fern-grotto-4

Looking out from the grotto, you can see droplets of water dripping off the ferns.

fern-grotto-5

The whole thing looks like a Victorian garden feature.

wave-breaking-fern-grotto-beach

The ocean side of Fern Grotto Beach has some nice rocks for the waves to break on.

seals-from-ocean-side

Here are the seals again, seen from the ocean side with my zoom lens.

seal-from-ocean-side-unzoom

Without the zoom, it is rather difficult to make out the seals—the group of them are just a few dots extending the lines of the cliff to their right.

Chrysolina-bankii

This beetle on the trail appears to be a Chrysolina bankii, based on a Google Lens search and looking at many pictures of the species.

group-from-back

Here is the walking group seen from the back.

canada-geese

Wilder Beach is closed to the public, but with my zoom lens, I could just see the canada geese in Wilder Creek from the Wilder Beach Overlook.

california-poppy-1

California poppies are still in bloom.

california-poppy-2

But many of the poppies have lost their petals and are showing red skirts around their seed pods.

After the walk, we gathered at the picnic tables between the chicken coop and the goat pasture and ate the lunches we had brought. The group seems like a nice enough group of people, and I would be willing to go walking with them again, though the level of exercise was rather minimal (I got far more exercise bicycling there and back). The visitor center was open, so I picked up a free map of Henry Cowell Redwoods state park while I was there.

Secret Walks: Significant Trees

Filed under: Uncategorized — gasstationwithoutpumps @ 14:16
Tags: , , , ,

My wife and I did not do a walk in the Secret Walks series on April 2, and on April 3 we just walked to and from the Colligan Theater to see the new play Remains to be Seen.  The acting was good (though the parts had clearly been written for some of the specific actors), but the script was weak—the jokes were predictable and the attempts at deeper emotional appeal fell a bit flat.  The audience liked it (over half rose for a standing ovation), but that says more about the uncritical nature of Santa Cruz’s Sunday matinee audience than anything else.

On Saturday April 9, we decided to do a short walk, trying to use the city’s self-guided Downtwon Significant Tree Walk, which lists, gives photos of, and provides interesting information on 25 trees, but lacks a map or clear directions.

downtown-trees-map

The route starts at City Hall, down Church, then up Cedar Street, and Mission Street to Mission Plaza (the red line). It is then supposed to go down Green Street (the orange line), but we got confused and went back down Mission, Center, and Chestnut, before we figured out that the trees we were missing might be on Green (the purple line). The route continues down Chestnut to Walnut, ending at Calvary Episcopal Church (the green line). I added a return to City Hall to this map, but in reality we started from home and went to Mission Hill Creamery for ice cream after the walk, before heading home. Click for higher-resolution map

The drawn route is about 1.42 miles, but our detour added about 0.25 miles to that. With the walk for ice cream and to and from home, the total distance was about 4.1 miles.

Canary-Island-date-palm

The Canary Island date palm (Phoenix canariensis) at City Hall has a rather curved base—probably because it was planted too close to the building.

Cockspur-coral-1

The cockspur coral tree(Erythrina crista-galli) has gotten a lot bigger since the city put out the guide to downtown trees.

house-finch-on-cockspur-coral

There was a house finch posing on the top of the cockspur coral, and I managed to get a decent shot of it.

Cockspur-coral-2

The flowers of the cockspur coral are rather interesting shapes.

floss-silk-tree-bark

The bark of the floss silk tree (Ceiba speciosa) has nice spikes, though I think that the tree on the other wing of City Hall has nicer spikes than the one they picked out for their photos. This is from the tree they picked.

floss-silk-tree

Here is the floss silk tree viewed from across the street in front of the Civic Auditorium.

jacaranda

The next tree on the list is a jacaranda, but it is not very impressive when not in bloom.

Japanese-cryptomeria

In front of the Civic Auditorium is a Japanese cryptomeria (Cryptomeria japonica).

flowering-cherry

They also called out this flowering cherry, though it was not in bloom.

sad-cherry-blossoms

Well, there were a few sad blossoms left on the tree.

owl-box

Also in front of the Civic Auditorium is this fine owl nesting box, though I have no evidence that any birds have ever nested in it.

unlisted-cherry-blossom

Next to the owl box was a cherry tree that still had exuberant blossoms, though it was not called out on the city’s list.

unlisted-cherry

Here is the whole of the unlisted cherry tree.

angels-trumpet

The city listing had this angel’s trumpet (Brugmansia x candida) next, though it is unimpressive when not in bloom. There are a lot of angel’s trumpets around town, and this specimen is not one of the best.

lily-of-the-valley-tree

Across the street by the Greek orthodox church is a lily of the valley tree (Crinodendron patagua).

lily-of-the-valley-tree-leaves

The leaves of the lily of the valley tree look a bit like oak leaves.

magnolia-grandiflora

In the CruzIO parking lot is a large Magnolia grandiflora. I’m not fond of these trees, as they drop stiff waxy leaves that clog drain grates, and I find the smell of the flowers slightly unpleasant. I prefer magnolias with softer leaves and a shorter blooming season (there are many magnolias of different types around town).

There is supposed to be a katsura tree on the walk between the magnolia and the gingkos, but we were unable to find it—we could not even figure out where it would have been from the photo in the city handout, as we could not identify the buildings either. Perhaps someone with a better memory of Santa Cruz downtown buildings or trees could help us out here.

new-gingko-leaves

The gingko trees on Cedar Street were just coming into leaf.

black-walnut

The black walnut in the parking lot had been slated for removal a decade or more ago, but pruning it way back and letting the crown regrow saved the tree.

red-oaks

The red oaks (Quercus rubra) in front of the parking garage provide some welcome shade at the entrance to the walkway.

red-oak-leaves

The red-oak leaves make a nice contrast with the sky.

orange-flower-gum-1

This orange flowering gum (Corymbia ficifolia) is a little hard to identify without the orange flowers.

orange-flower-gum-2

The newly built condos clearly took away about a quarter of the tree canopy.

orange-flower-gum-seed-pods

The seed pods of the orange flowering gum have some interesting color patterns.

bunya-bunya

On the top of the hill, in the Santa Cruz Mission state park, is a bunya-bunya (Araucaria bidwillii).

bunya-bunya-leaves

I used my zoom lens to get a more detailed view of the bunya-bunya leaves, without having to go around to the entrance to the state park.

Chilean-wine-palm

The Chilean wine palm (Jubaea chiliensis) is also in the state park.

date-palm

This date palm (Phoenix dactilifera) is in Mission Plaza park.

linden

I’m not sure whether this linden (Tilia spp.) is dead or just hasn’t leafed out yet this spring.

linden-detail

Either way, the trunk has an interesting texture.

dawn-redwood

Also in Mission Plaza is this dawn redwood (Metaequoia glyptostroboides), which is not a California native, but which seems to do well here.

copper-beech

The copper beech (Fagus sylvatica ’Atropuncea’) on Cross Street was difficult for us to find.

copper-beech-leaves

The smooth bark and colored leaves are distinctive for the copper beech, and they make a nice display against the sky.

deodar-cedar

On the same property on Green Street as the copper beech is this deodar cedar (Cedrus deodara).

deodar-cedar-needles

The deodar cedar needles in close-up.

coast-redwood

This coast redwood (Sequoia sempervirens) on Union Street is the locally endemic redwood—they get a bit big for city trees.

Norfolk-Island-pine

This star/Norfolk Island pine (Araucaria heterophylla) is visible from Chestnut, but is really on Rincon by the apartment building there.

coast-redwood-feet

I like the way that this coast redwood is flowing over the sidewalk, so I photographed it, even though it isn’t called out on the city list.

plane-trees

These London plane trees (Platanus x hispanica (acerifolia)) are on Walnut Street. (Sorry—no walnut trees there, and no chestnuts on Chestnut Street either—in fact, most of the tree-named streets downtown don’t have the trees they are named after.) The plane trees in town are all rather sickly with anthracnose and powdery mildew, but they survive—we have a couple in our yard too, planted by the previous owners. Neither my wife nor I care much for them.

site-of-missing-tree

The last tree on the last was a douglas fir, but it was taken out a few years ago—that green lawn to the left of the church is where it used to be.

After the missing douglas fir, we went to Mission Hill Coffee and Creamery for ice cream. I ordered two scoops, but as I was handing my wife her cone, the top scoop rolled off my cone and landed on the sidewalk, so I ended up with only the fig-goat cheese ice cream, and not the green tea ice cream as well.

wisteria

This wisteria across California Street from the high school is not part of the route, but it is a listed “heritage tree” by the city, and it is just coming to the end of its blooming season.

Next Page »

%d bloggers like this: