Thursday, 27 July 2017

Fluminicola umpquaensis & Fluminicola fresti: Two new species of Pebblesnail from Oregon.

Pebblesnails, Fluminicola spp., are small globose to conical freshwater Snails found in the watersheds of western North America from California to British Colombia. The Snails inhabit a range of habitats from small seeps and springs to large rivers and lakes, with the group thought to contain many species, each with a limited range and specific habitat requirements. Despite this, only twenty-five species have been described to date, fourteen of which come from the Sacramento River Basin and six from the Columbia River Basin, with many other known populations that have historically been grouped into a small number of widespread populations, something which is now believed to be erroneous. Many populations of Pebblesnails are thought to be at risk due to Human activities, and gaining a proper understanding of their taxonomy is crucial before any legal protection for these species can be gained.

In a paper published in the journal ZooKeys on 8 June 2017, Robert Hershler of the Department of Invertebrate Zoology at the Smithsonian Institution, and Hsiu-Ping Liu and Niko Hubbart of the Department of Biology at the Metropolitan State University of Denver, describe two new species of Pebblesnails from the Umpqua and Rogue River Basins in Oregon.

Hershler et al. carried out gene sequencing and morphometric analysis of 161 Pebblesnails from 35 sites in the Umpqua and Rogue River basins. From this they were able to detect three distinct clades of Pebblesnails. One of these was identified as a new population of Fluminicola multifarius, a species previously known from the Sacramento and McCloud river basins in California. The distribution of this species is now extended to include the southern part of the upper Rogue River Basin. This also raises the possibility that the species might be found in the Klamath River Basin, which lies between the Sacramento and Rogue basins, and where the species has not yet been recorded. The remaining two populations are described as new species. 

Shells, opercula and radula, Fluminicola multifarius from the Rogue River Basin in Oregon. (A) Shell. (B) Shell. (C) Shell. (D), (E) Opercula (outer, inner sides). (F) Portion of radular ribbon. (G) Central teeth. (H) Lateral teeth. Scale bars: (A)–(B) 1.0 mm; (D)–(E) 250 μm; (F), 100 μm; (G)–(H) 10 μm. Hershler et al. (2017).

The first new species is named Fluminicola fresti in honour of the late Terrence Frest, for his contributions to the study of malacology in the northwestern United States. This species was found in spring-fed environments in the upper parts of both river basins, to the north of Little Butte Creek. The species is small to medium sized for the genus, reaching 2.3 to 5.5 mm in height, with a trochoidal to ovate-conic shell, 3.5-4 whorls when fully grown and an ovate aperture. 

Shells, opercula and radula, Fluminicola fresti. (A) Holotype. (B), (C) Sympatric ovate-conic and trochiform shell morphs, respectively. (D) Shell. (E), (F) Opercula (outer, inner sides). (G) Portion of radular ribbon. (H) Central teeth. (I) Lateral teeth. Scale bars: (A)–(D) 1.0 mm; (E)–(F) 250 μm; (G) 100 μm; (H)–(I) 20 μm. Hershler et al. (2017).

The second new species is named Fluminicola umpquaensis, meaning ‘from Umpqua’, the species being widely distributed in the Umpqua River Basin but not known from elsewhere. The species is large for the genus, reaching 9.5 mm in height, with a conical and a spire that tends to erode, leaving it with somewhere over 3.5 whorls when mature. The species was found in springs, streams and rivers in the Umpqua Basin.

Shells, opercula and radula, Fluminicola umpquaensis. (A) Holotype. (B) Shell. (C) Shell. (D), (E) Opercula (outer, inner sides). (F) Portion of radular ribbon. (G) Central teeth. (H) Lateral teeth. Scale bars: (A)–(E), 1.0 mm; (F), 100 μm; (G)–(H), 10 μm. Hershler et al. (2017). 

See also...

http://sciencythoughts.blogspot.co.uk/2017/07/aenigmatoconcha-clivicola-new-species.htmlhttp://sciencythoughts.blogspot.co.uk/2016/12/dendronotus-arcticus-dendronotus.html

http://sciencythoughts.blogspot.co.uk/2016/09/sphendone-insolita-new-species-of.htmlhttp://sciencythoughts.blogspot.co.uk/2016/05/bothriembryon-sophiarum-new-species-of.html
http://sciencythoughts.blogspot.co.uk/2016/04/lacustrine-gastropods-from-late-miocene.htmlhttp://sciencythoughts.blogspot.co.uk/2016/03/echinolittorina-nielseni-new-species-of.html
Follow Sciency Thoughts on Facebook.

Mars reaches Solar Conjunction.

The planet Uranus will reached Solar Conjunction (i.e. be directly on the other side of the Sun from the Earth) on Thursday 27 July 2017. This means that it will both be at its furthest from the Earth this year, about 2.5 AU (2.5 times the average distance between the Earth and the Sun, or about 374 000 000 km), and completely obscured by the Sun. 

The relative positions of Uranus, the Sun and Earth at Solar Conjunction. NASA.

Mars orbits the Sun at an average distance of 1.5 AU, completing one orbit around the Sun every 1.88 years. The planet is now home to numerous man-made instruments, all of which receive regular instructions from Earth. The two planets reach Solar Conjunction roughly once every two years, during which time all of these instruments are cut off from Earth for two weeks, with the majority simply being shut down.

See also...

http://sciencythoughts.blogspot.co.uk/2017/05/relatively-recent-volcanic-activity-in.htmlhttp://sciencythoughts.blogspot.co.uk/2015/04/relatively-recent-volcanic-activity-in.html
http://sciencythoughts.blogspot.co.uk/2015/04/relatively-recent-volcanic-activity-in.htmlhttp://sciencythoughts.blogspot.co.uk/2015/03/hydrated-silicate-minerals-in-mariner.html
http://sciencythoughts.blogspot.co.uk/2014/10/interpreting-landslide-deposits-in.htmlhttp://sciencythoughts.blogspot.co.uk/2014/04/ice-in-martian-impact-craters.html
Follow Sciency Thoughts on Facebook.

Flooding kills ten in West Bengal after water released from the Durgapur Barrage

Ten people are known to have died and thousands have been evacuated from their homes after water was released from the Durgapur Barrage on Thursday 27 July 2017. The water was released to prevent stress to the dam, following a rise in water behind the dam, caused by heavy rainfall associated with the Asian summer monsoon. However the state's Chief Minister, Mamata Banerjee, has suggested that the flood, and other similar floods following releases of water from other dams in India this week, has been caused not by unexpectedly high rainfall levels, but by an accumulation of silt behind the dam, leading to a reduced water retaining capacity, something which should be prevented by regular dredging of dam lakes.

Flooding in the town of Ghatal in West Midnapore district, West Bengal, on 27 July 2017. Hindustan Times.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate. This situation is particularly intense in South Asia, due to the presence of the Himalayas. High mountain ranges tend to force winds hitting them upwards, which amplifies the South Asian Summer Monsoon, with higher winds leading to more upward air movement, thus drawing in further air from the sea. 

Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

See also...

http://sciencythoughts.blogspot.co.uk/2017/01/collapse-at-illegal-coal-mine-kills-at.htmlhttp://sciencythoughts.blogspot.co.uk/2016/08/thousands-evacuated-after-landslide.html
http://sciencythoughts.blogspot.co.uk/2015/07/series-of-landslides-kills-at-least-30.htmlhttp://sciencythoughts.blogspot.co.uk/2014/06/13-killed-by-lightning-in-west-bengal.html
http://sciencythoughts.blogspot.co.uk/2013/09/man-killed-in-darjeeling-landslide.html
Follow Sciency Thoughts on Facebook.

Magnitude 5.1 Earthquake in Antofagasta Province, Chile.

The United States Geological Survey recorded a Magnitude 5.1 Earthquake at a depth of 75.7 km, 98 km to the southeast of the city of Antofagasta in the Chilean province of the same name, slightly after 6.10 am local time (slightly after 10.10 am GMT) on Wednesday 26 July 2017. There are no reports of any damage or injuries associated with this event, but people have reported feeling locally.
 
The approximate location of the 26 July 2017 Antofagasta Earthquake. USGS.
 
Chile is located on the west coast of South America, which is also the convergent margin between the Nazca and South American Plates. The Nazca Plate is being subducted beneath the South American Plate and is sinking beneath the South American Plate. This is not a smooth process, the rocks of the two plates continuously stick together then, as the pressure builds up, break apart again, causing Earthquakes. As the Nazca Plate sinks deeper it is partially melted by the heat of the Earth's interior. Some of the melted material then rises up through the overlying South American Plate as magma, fuelling the volcanoes of the Chilean Andes.
 
 The subduction of the Nazca Plate beneath the South American Plate, and how it causes Earthquakes and volcanoes. Pacific Earthquake Engineering Research Center.
 
Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.
 
See also...
 
http://sciencythoughts.blogspot.co.uk/2017/01/wildfires-kill-at-least-eleven-in-chile.htmlhttp://sciencythoughts.blogspot.co.uk/2016/12/magnitude-76-earthquake-on-south-coast.html
http://sciencythoughts.blogspot.co.uk/2016/09/magnitude-55-earthquake-in-central-chile.htmlhttp://sciencythoughts.blogspot.co.uk/2015/11/magnitude-68-earthquake-in-central-chile.html
http://sciencythoughts.blogspot.co.uk/2015/10/eruption-on-mount-lascar-northern-chile.htmlhttp://sciencythoughts.blogspot.co.uk/2015/10/eruption-on-mount-copahue.html
Follow Sciency Thoughts on Facebook.

Wednesday, 26 July 2017

The Delta Aquarid Meteors.

The Delta Aquarid Meteor Shower peaks each year on 27-28 July, when the shower can produce 10-20 meteors per hour. Best viewing this year is predicted to be between midnight and 2.00 am (this will be in local time wherever they are viewed from, as the time reflects the orientation of the planet to the rest of the Solar System), when the radiant point of the shower (point from which the meteors appear to radiate), which is close to the star Delta Aquari (hence the name) will be highest in the sky. At this time this year the Moon will be in a waxing crescent phase, so that viewing will be little impeded by moonlight.


The Delta Aquarids are thought to be caused by the Earth passing through the trail of Comet 96P/Machholz, where it encounters thousands of tiny dust particles shed from the comet as its icy surface is melted (strictly sublimated) by the heat of the Sun. 96P/Machholz is a short period, Jupiter Family Comet, crossing our orbit every 5.24 years, but the trail of particles shed by it forms a constant flow,

See also...

http://sciencythoughts.blogspot.co.uk/2017/04/gobekli-tepe-does-ancient-anatolian.html
http://sciencythoughts.blogspot.co.uk/2017/05/the-2017-eta-aquarid-meteors.html

http://sciencythoughts.blogspot.co.uk/2017/04/fireball-over-southern-united-sates.html
http://sciencythoughts.blogspot.co.uk/2017/04/the-lyrid-meteors.html
http://sciencythoughts.blogspot.co.uk/2017/03/fireball-over-northern-texas.html
http://sciencythoughts.blogspot.co.uk/2017/03/fireball-meteor-over-british-columbia.html

Follow Sciency Thoughts on Facebook.

Strongyloides stercoralis: Determining the origin of Human infection in a parasitic Nematode.

Parasitic Nematodes of the genus Strongyloides infect the guts of a wide range of Vertebrate hosts, including Birds, Reptiles, Amphibians, and Mammals, as well as Humans, livestock, and companion animals. Two species are known to infect Humans, Strongyloides fuelleborni, which has two subspecies, one found in tropical Africa and the other in Papua New Guinea, and Strongyloides stercoralis, which has a cosmopolitan distribution, though most infections occur in the tropics and subtropics, and which is also found in Dogs and Chimpanzees.

In a paper published in the journal Scientific Reports on 7 July 2017 a team of scientists led by Eiji Nagayasu of the Division of Parasitology at the University of Miyazaki published the result of a phylogenetic study of Strongyloides stercoralis, using four gene sets plus morphometric analysis. Nematodes were isolated from Humans from Japan, Myanmar, Thailand, Laos, Uganda, the Central African Republic and Tanzania, as well as Dogs from Japan and Myanmar and Chimpanzees from Tanzania, with a view to establishing a phylogenetic tree and potentially determining the origin of infection in Humans.

 
A Strongyloides stercoralis nematode. Oklahoma State University.

Nagayasu et al. found that the Nematodes could be divided into two main clades (groups with common ancestry), one of which contained all the Human derived worms, plus the Chimpanzee derived worms and all worms from Dog infections in Japan, and some of the worms from Dogs in Myanmar. The second clade was contained entirely worms obtained from Dogs in Myanmar. They interpret this data as indicating that Strongyloides stercoralis infection originated in Dogs and has spread to Humans during the two species’ long association. The first clade has apparently made the jump between Dogs and Humans (and subsequently to Chimpanzees, which are very similar to Humans in immunological terms), while the second clade not made this jump. 

Median-joining haplotype network for the mitochondrial Cox1 gene. Each circle represents one haplotype. The size of the circle represents the number of hosts that harbour the given haplotype. The colour inside the circle indicates the host species/geographical origin (country). Numbers beside the branches indicate the number of mutational steps between haplotypes (no number is shown in case of a single-step difference). Branch lengths are roughly proportional to the number of mutational steps. Nagayasu et al. (2017).

Interestingly, a previous study of Strongyloides stercoralis, published in 2014 that looked as a smaller number of gene-sets and which concentrated on infections in Cambodia, had also identified two major clades within the total population of Nematodes, one of which was associated principally with Dogs, but which was also found in some Humans. However, re-examination of this data reveals that all of the Humans infected with the second strain were immunocompromised individuals the HIV from Myanmar; HIV is known for its destruction of the immune system, and often individuals infected with it are infected by organisms which do not usually infect Humans, or even which are not usually pathogenic at all, suggesting that such individuals would be vulnerable to a strain of Nematodes which normally attacks only Dogs.

See also...

http://sciencythoughts.blogspot.co.uk/2015/04/tripius-gyraloura-sphaerularid-nematode.htmlhttp://sciencythoughts.blogspot.co.uk/2015/04/philometrid-nematodes-from-perciform.html
http://sciencythoughts.blogspot.co.uk/2015/03/a-new-species-of-capillariid-nematode.htmlhttp://sciencythoughts.blogspot.co.uk/2014/12/two-new-species-of-pinworms-from.html
http://sciencythoughts.blogspot.co.uk/2014/11/a-parasitic-heterakid-nematode-from.htmlhttp://sciencythoughts.blogspot.co.uk/2014/10/parasite-infections-in-german-soldiers.html
Follow Sciency Thoughts on Facebook.

Flooding leads to 111 known deaths as monsoon arives in Gujarat.

The number of known deaths has risen to 111 in flooding associated with the onset of the Asian summer monsoon in the Indian state of Gujarat after the bodies of a family of seventeen in the village of Khariya in Banaskantha District, and it is feared that many more bodies will be discovered as the floodwaters recede. Many of the worst ht areas were along the banks of the river Banas, where water was released from the Dantiwada Dam at an increased rate after floodwaters from Rajasthan threatened to overstress the dam. This led to a number of villages close to the river being inundated.  A similar release of waters from the Sipu Dam has also lead to flooding on the Sipu River.

Flooding in Banaskantha District, Gujarat, on 25 July 2017. IANS.

Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate. This situation is particularly intense in South Asia, due to the presence of the Himalayas. High mountain ranges tend to force winds hitting them upwards, which amplifies the South Asian Summer Monsoon, with higher winds leading to more upward air movement, thus drawing in further air from the sea. 

Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

See also...

http://sciencythoughts.blogspot.co.uk/2017/04/explosion-kills-three-workers-at.htmlhttp://sciencythoughts.blogspot.co.uk/2015/07/landslide-kills-three-on-pune-mumbai.html
http://sciencythoughts.blogspot.co.uk/2015/06/flooding-feared-to-have-killed-at-least.htmlhttp://sciencythoughts.blogspot.co.uk/2015/06/landslide-kills-five-in-maharashtra.html
http://sciencythoughts.blogspot.co.uk/2014/07/at-least-41-dead-following-landslide.htmlhttp://sciencythoughts.blogspot.co.uk/2014/06/flooding-after-mumbai-hit-by-freak-waves.html
Follow Sciency Thoughts on Facebook.