Twenty specimens of Acentrogobius ocyurus (Jordan and Seale, 1907) were collected in Manko, Okinawa-jima Island, Japan and Sulu Sea side of Puerto Princesa City, Palawan Island, Philippines. As the ...species had previously been reported from the South China Sea, Andaman Sea, and northern Australian waters, these specimens from Okinawa and Palawan represent the first records of the species from Japan and the Sulu Sea. Acentrogobius ocyurus was found on muddy substrata at the lowest tidal zone of the mudflat and was often found in burrows of mangrove pistol shrimp, Alpheus richardsoni Yaldwyn, 1971. Morphological traits suggested that A. ocyurus is closely related to A. globiceps (Hora, 1923), A. kranjiensis (Herre, 1940), and Acentrogobius sp. (“Suzume-haze” in Japanese name), with several homologous features including, the transverse pattern of the sensory papillae on the cheek, caudal fin pointed in middle, a black stripe behind the eye along the anterior oculoscapular canal, bright blue spots laterally on the body, and an oblique yellow stripe across the upper part of the caudal fin.
In this study, we present a novel solution in Einstein–Maxwell theory that represents the magnetized Taub–NUT spacetime incorporating the Manko–Ruiz parameter. We investigate various aspects of this ...spacetime, including its curvature, closed timelike curve, and electromagnetic fields. Additionally, we explore the phenomenon of Hawking radiation within this magnetized spacetime by employing the tunneling picture. Our findings shed light on the unique characteristics and physical implications of the magnetized Taub–NUT spacetime with the Manko–Ruiz parameter.
Estuaries are often considered important filters for inorganic and organic nutrients, as they are located between the land and sea. This study reports on the fluvial fluxes and estuarine ...transformations and retention of dissolved nutrients (total oxidized nitrogen TON = NO2− and NO3−), NH4+, PO43−, and dissolved organic carbon (DOC) in Manko estuary, Okinawa, Japan. The transport and transformation of dissolved nutrients and DOC varied widely among the eight conducted surveys due to variations in freshwater discharge and subsequent flushing times. Under high fluvial discharge, particularly during the May–June rainy season, the transport of nutrients and DOC accounted for up to 70%, 88%, 93%, and 53% of the annual transport of TON, NH4+, PO43−, and DOC, respectively. The flushing times of river water into the estuary, which varied from 0.5 to 46 days, were important in determining the degree to which fluvial nutrients were transformed and retained within the estuary. The effect of long flushing times was evident during the dry months (December–March), when biological and geochemical processes within the estuary removed most of the fluvial nutrients and DOC.
Periodic orbits and escapes in dynamical systems Contopoulos, George; Harsoula, Mirella; Lukes-Gerakopoulos, Georgios
Celestial mechanics and dynamical astronomy,
07/2012, Letnik:
113, Številka:
3
Journal Article
Recenzirano
Odprti dostop
We study the periodic orbits and the escapes in two different dynamical systems, namely (1) a classical system of two coupled oscillators, and (2) the Manko-Novikov metric which is a perturbation of ...the Kerr metric (a general relativistic system). We find their simple periodic orbits, their characteristics and their stability. Then we find their ordered and chaotic domains. As the energy goes beyond the escape energy, most chaotic orbits escape. In the first case we consider escapes to infinity, while in the second case we emphasize escapes to the central “bumpy” black hole. When the energy reaches its escape value, a particular family of periodic orbits reaches an infinite period and then the family disappears (the orbit escapes). As this family approaches termination it undergoes an infinity of equal period and double period bifurcations at transitions from stability to instability and vice versa. The bifurcating families continue to exist beyond the escape energy. We study the forms of the phase space for various energies, and the statistics of the chaotic and escaping orbits. The proportion of these orbits increases abruptly as the energy goes beyond the escape energy.
Estuaries are often considered important filters for inorganic and organic nutrients, as they are located between the land and sea. This study reports on the fluvial fluxes and estuarine ...transformations and retention of dissolved nutrients (total oxidized nitrogen TON = NO2- and NO3-), NH4+, PO43-, and dissolved organic carbon (DOC) in Manko estuary, Okinawa, Japan. The transport and transformation of dissolved nutrients and DOC varied widely among the eight conducted surveys due to variations in freshwater discharge and subsequent flushing times. Under high fluvial discharge, particularly during the May-June rainy season, the transport of nutrients and DOC accounted for up to 70%, 88%, 93%, and 53% of the annual transport of TON, NH4+, PO43-, and DOC, respectively. The flushing times of river water into the estuary, which varied from 0.5 to 46 days, were important in determining the degree to which fluvial nutrients were transformed and retained within the estuary. The effect of long flushing times was evident during the dry months (December-March), when biological and geochemical processes within the estuary removed most of the fluvial nutrients and DOC.
Data on leaf phenological traits and longevity of mangroves are important for improved understanding of the adaptation strategies, growth, and productivity of these trees. We studied leaf ...phenological traits and longevity of
Rhizophora stylosa
,
Bruguiera gymnorrhiza
, and
Kandelia obovata
monthly from April 2008 to March 2009. Both tree sampling (direct observation) and litterfall (indirect observation) were used. All leaves and branches of each sample tree were numbered and marked with tags at the beginning of the experiment. Peaks of leaf recruitment and death occurred in July and June, respectively, for
B. gymnorrhiza
and
K. obovata
but both occurred in July for
R. stylosa
. Leaf recruitment for all the species was lowest in January; leaf death was minimum in December for
R. stylosa
and
B. gymnorrhiza
, and in January for
K. obovata
. Leaf recruitment for the three species was significantly correlated with monthly mean air temperature and monthly hours of sunshine.
K. obovata
and
R. stylosa
leaf death was correlated with monthly mean air temperature, monthly hours of sunshine, monthly mean air vapor pressure deficit, and monthly rainfall;
B. gymnorrhiza
leaf death was not correlated with any environmental factors. Specific leaf area for
R. stylosa
(45.4 ± 1.0 cm
2
g
−1
) and
K. obovata
(48.6 ± 0.8 cm
2
g
−1
) was not significantly different, but means for these two species were significantly different from that for
B. gymnorrhiza
(71.0 ± 2.8 cm
2
g
−1
). Mean leaf longevity was 13.9 months for
R. stylosa
, 17.2 months for
B. gymnorrhiza
, and 12.1 months for
K. obovata
. Different measured variables between
B.
gymnorrhiza
and the other two species may have been because of the growth strategy and shade tolerance of
B.
gymnorrhiza
. Mean leaf longevity increased with increasing mean annual air temperature.
The spatial and temporal behaviours of the organotin compounds (OTCs) (butyl- and phenyltin) were investigated in the Manko and Okukubi protected estuarine ecosystems on Okinawa Island, Japan from ...February to October 2006. Butyltin compounds (BTCs) were frequently detected in all seasons, while phenyltin (PhTs) were found in winter and early spring. In Manko estuary, the total mean concentrations of BTCs and PhTs were 22.78 ± 30.85, (mean ± SD, n = 53) and 0.08 ± 0.27 ng(Sn) L
−1
, respectively. In Okukubi estuary, BTCs and PhTs were 12.58 ± 23.96 and 0.47 ± 1.67 (n = 55) ng(Sn) L
−1
, respectively. The Manko sediments can be classified as lightly contaminated, while the Okukubi sediments were uncontaminated with tributyltin (TBT). The mean levels of TBT shown in Manko estuary exceeded the threshold level and represent an ecotoxicological risk to sensitive aquatic life. Generally, the present study reports the occurrence and continuous input of OTCs in the protected estuaries, even 16 years after legal restriction of TBT usage in coastal waters was implemented by the Japanese Environmental Authorities.
Tidal flats in Okinawa are now facing various environmental crises. Large-scale reclamation in the southern central region of Okinawa, where many tidal flats used to exist, has continued since the ...1970s. If reclamation keeps up its present pace, almost all of the tidal flats of the southern central Okinawa will disappear in the near future. Tidal flats in northern Okinawa have been greatly affected by clayey silt inflows caused by development on land. One consequence has been simplification of the tidal flat environment and a loss of benthic species diversity. Also, at Manko tidal flat, designated as a wetland of international importance under the Ramsar Convention on Wetlands, rapid sedimentation of clayey silt has led to decreases in benthic animals and plants as well as water birds. Most of the shoreline of Okinawa has been converted or is in the process of being converted to artificial breakwaters, and many forms of life restricted to sandy beach, salt-marsh and coastal wood environments exist on the extreme margin of survival. We have only scarce knowledge of the present state of most organisms living in tidal flats of Okinawa. At the same time, the status of tidal flat environments on Okinawa is worse than it has ever been.
JLL s Pittsburgh office welcomes Ed Manko to the local property management team as Group Manager, effective immediately. Manko comes to JLL with experience in the leadership role, most recently as a ...Senior Vice President, Director at a large commercial real estate firm.
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