Lipid content and composition of the pink shrimp, Pandalus montagui (Leach) (Crustacea: Decapoda)
Samples of pink shrimp, Pandalus montagui (Leach), were taken in winter from the estuary of the River Crouch and Lynn Well in the Wash. Males and ovigerous females (analysed without the eggs) contained 1 to 2% wet wt lipid and females with maturing ovaries between 3 and 6%. Transitional shrimps were starting to develop ovaries and had intermediate lipid contents. The major lipid classes were triacylglycerol, free sterol, and phospholipid. Variations in the total lipid content of males and ovigerous females were due mostly to fluctuations in hepatopancreas triacylglycerol, whereas production of eggs in maturing females necessitated synthesis of both triacylglycerol and phospholipid. The major phospholipids were choline and ethanolamine phosphoglycerides (45 and 35% total lipid P, respectively), both rich in ether lipids. The major egg phospholipid was choline phosphoglyceride (73% total lipid P). Fatty acid composition was typically crustacean and fairly unsaturated, phospholipid fatty acids being more unsaturated than those from triacylglycerol; both fractions from eggs were relatively rich in monoenoic acids compared with those of adult shrimps. Compared with the previously studied polar hippolytid shrimp Chorismus antarcticus, P. montagui contains less muscle phospholipid (and hence less total lipid) and less carotenoid pigment; females produce a larger number of smaller eggs than Chorismus antarcticus, and have a greater annual reproductive effort.
Measurements of aerial admittance as a function of height above a snow surface show that when the surface temperature is below freezing, the aerial performance is insensitive to slight surface irregularities.
The first observations are presented from Halley, Antarctica, of quasi-periodic (QP)_VLF intensity variations modulated at the frequency of concurrent Pc3 magnetic pulsations. Seen on broadband frequency-time plots, the QP emissions are of both the dispersive and non-dispersive types. From the frequency and phase variation with time of the QP emissions and magnetic pulsations, estimates are obtained of the travel times of the ULF waves from the interaction region to the ground. The observations appear consistent with the idea of modulation of a pre-existing VLF hiss source in the magnetosphere by the compressional components of ULF waves. A significant change in the travel time during one event is consistent with a crossing of the plasmapause by the Halley fieldline.
A stock of biotite-muscovite-garnet leucogranite crops out in the lower course of Río Cisnes as an unusual minor lithology within the predominantly dioritic to tonalitic North Patagonian Batholith. Foliated and unfoliated varieties are present—the former are nearer to the main lineament of the Liquin˜e-Ofqui Fault Zone (LOFZ). Two-feldspar thermometry indicates equilibration temperatures above 600°C, for pressures probably not over 3 kbar, as suggested by the Mn-rich garnet composition. A Rb-Sr whole-rock isochron age of 9.6 ± 0.4 Ma (1σ error) probably indicates the time of magma crystallization. 40Ar-39Ar ages of 6.6 ± 0.3 Ma on muscovite and 5.5 ± 0.4 Ma on biotite are cooling ages from which a moderate average uplift/denudation rate (∼ 1 mm/yr) may be calculated. Paucity of occurrence, distribution close to the LOFZ and a near minimum-melt composition all suggest that the leucogranite magma was derived by partial melting of the lower crust, perhaps by decompression melting at a time when uplift/denudation rates were high (4 mm/yr or more are required). Regional evidence for rapid Holocene uplift in the immediate vicinity of the LOFZ substantiates the feasibility of the proposed petrogenetic model, which may be valid in other strike-slip orogenic environments.
Egg production in three species of calanoid copepods Rhincalanus gigas, Calanoides acutus and Calanus simillimus was investigated via incubations of females and recovery of eggs from net hauls made around South Georgia during January 1993. Average daily egg production was highest for the sub-Antarctic C. simillimus, (15.5 eggs female−1 d−1). This species normally spawns in the spring in the central part of its geographical range but was apparently delayed by the colder waters found around South Georgia. For R. gigas and C. acutus egg production averaged 8.9 and 6.0 eggs female−1 d−1, respectively. The former species appeared to be undergoing protracted recruitment while the population of the latter was preparing to overwinter. Considerable interstation variability existed, although no relationships were apparent between surface chlorophyll concentrations and either egg production in experiments or in the numbers of eggs recovered by the nets. Clutch size (eggs produced spawning female−1 d−1) did not differ significantly between the three species although the maximum clutch size recorded for R. gigas (94 eggs) was almost twice that of C. simillimus. Samples taken from the Bellingshausen Sea during the latter part of 1992 indicated that recruitment of R. gigas and C. acutus commenced in early December in this region when adult females were concentrated in the surface 250 m and a diatom bloom was developing. Egg numbers were highest in the surface 50 m (up to 350 m−-3) at both the Bellingshausen and South Georgia stations. At the latter site females migrated into these surface layers at night; thus it would appear that spawning is largely nocturnal and linked to diurnal migratory behaviour.
Clouds of energetic electrons, injected sporadically into the nightside magnetosphere during substorm expansion phase onsets, can generate VLF whistler mode noise through the gyroresonance instability, which may then be observed on the ground or in space. Although these substorm-related chorus events (SCEs) have been reported occasionally in the literature, there seems to have been no systematic study, probably because of the lack, until now, of a well-adapted experimental technique. The VLF/ELF Logger Experiment (VELOX) instrument, located at Halley, Antarctica (76°S, 26°W, L = 4.3), is, however, particularly well suited to a systematic study of this aspect of the substorm phenomenon. The data exist almost continuously from January 1992 onward, at 1-s time resolution in eight quasi-logarithmically spaced frequency bands covering the range 0.25–10 kHz. For this paper, 327 days of continuous data from 1992 have been analyzed. The 243 SCEs identified were observed on about 50% of days, almost exclusively in the 2300–0600 MLT local time range, and were characterized by limited duration (typically, ∼10 min at 1.5 kHz) and upward frequency drift of a band of usually weak and relatively unstructured chorus at a rate of ∼200 Hz min−1 between 0.5 and 5 kHz (corresponding to parallel electron energies in the range ∼10–100 keV). This drift is consistent with the combined eastward and inward motion of the resonant electrons due to azimuthal gradient-curvature drift and radial E × B drift under the action of substorm-enhanced westward electric fields of order l mVm−1 near the equatorial plane. The limited MLT viewing window of the station implies an overall detection efficiency for SCEs of ∼20%. The inferred annual mean substorm rate, 1366 ± 188 year−1, and inter substorm interval, 5.5 ± 0.8 hours, are similar to the values derived using other techniques. However, the distribution of intervals between successive SCEs is different from that for substorm-related particle injections at geostationary orbit; in particular, the models around 1 hour rather than 2–3 hours. The SCE as seen by a VELOX-type VLF receiver with a wide field of view is an important alternative ground-observable substorm signature, complementary to those (such as bays and Pi 2 pulsations) indicated by magnetometers.
Inland Antarctic terrestrial ecosystems and biodiversity are poorly understood in comparison with Antarctic coastal regions. Microorganisms, as primary colonists, are integral to Antarctic soil ecosystem development, essential for pedogenesis and structuring the soil, and providing the nutrients necessary for the subsequent establishment of macroorganisms. This study analysed the microbial communities present in polygon soils of Coal Nunatak (Alexander Island, at the southern limit of the maritime Antarctic). Soils were analysed across three polygons (centre and margins) and at three depths (0-1, 1-2, 2-5 cm). Cyanobacterial communities were characterised using two complementary molecular biological approaches, temperature gradient gel electrophoresis and clone library analysis. The three polygons exhibited conspicuous differences in community composition, both between different polygons and spatially (horizontally and vertically) within a single polygon. Comparison of our data with that from previous studies using classical culture and morphological identification techniques clearly shows the need for more intensive research on patterns of microbial diversity in terrestrial habitats throughout the Antarctic. The majority of the 17 cyanobacterial genera identified at Coal Nunatak are thought to have ubiquitous distributions, while none are known only from the Antarctic. Three of the genera present are also known to be capable of being lichen photobionts.
Physiological mechanisms mediating carryover effects, wherein events or activities occurring in one season,habitat, or life-history stage affect important processes in subsequent life-history stages, are largelyunknown. The mechanism most commonly invoked to explain carryover effects from migration centreson the acquisition and utilization of resources (e.g. body mass, or individual ‘condition’). However, othermechanisms are plausible, e.g. trade-offs reflecting conflict or incompatibility between physiological regulatorysystems required for different activities or life-history stages (migration vs. reproduction). Herewe show that in female black-browed albatrosses (Thalassarche melanophris) the decision to reproduceor to defer reproduction, made prior to their arrival at breeding colonies after long-distance migration,is associated with condition-related (body mass, hematocrit, hemoglobin concentrations) and hormonal(progesterone, testosterone, estrogen-dependent yolk precursors) traits. In contrast, reproductive successshowed little association with condition but showed significant associations with the steroidogenic processesunderlying follicle development. Specifically, success was determined by reproductive readiness via differences in steroid hormones and hormone-dependent traits. Successful albatrosses were characterized by high progesterone and high estradiol-dependent yolk precursor levels, whereas failed albatrosses had high testosterone and low yolk precursor levels. Results are discussed with reference tomigratory carryover effects and how these can differentially affect the physiologies influencing reproductive decisions and reproductive success.
FacebookTwitterLinkedInEmailCEDAR CITY, Utah-While she will inherit former Juab High star Hannah Robins from a previous recruiting class, Southern Utah University women’s basketball coach Tracy Sanders is getting her ducks in a row by assembling her coaching staff which was finalized Wednesday.Sanders, a former assistant coach at Saint Mary’s, announced her decision in this regard, saying “these coaches will be terrific representatives of Southern Utah University and our women’s basketball program.”The staff consists of Tony Giannotti, Hailey Mandelko and Jay Johnson.Giannotti is a 2000 SUU graduate and played for the Thunderbirds’ men’s basketball team for two seasons. He has previously served as an assistant for both the Thunderbirds’ men’s (2000-01 season) and women’s (2003-2006) basketball teams in the past.In the interim, Giannotti has served as an assistant coach on women’s basketball staffs at Saint Mary’s, New Mexico State, Idaho State and San Jose State.While with the Bengals at Pocatello, Idaho, he won a Big Sky Conference championship in the 2013 season. While at New Mexico State, he helped the Aggies to a postseason appearance in 2010, the first time this had happened in Las Cruces, N.M. since 1994.Giannotti comes to Cedar City on his second tour of duty after serving as the girls’ basketball coach at Wasatch Academy. This past season, he led the Tigers to a 23-3 record and a Region 17 championship.Mandelko, a former SUU women’s basketball standout, returns to the program after a stint as the head coach of the Lexington High Minutewomen of Kearney, Neb.Mandelko was a key player on the Thunderbirds’ 2013-14 Big Sky champion roster and earned all-conference honors her junior season while also entering the Top 5 in program history for points in a season (467) and was in the top 8 in program annals for free throw percentage in a season (84.5 percent).The 2015 SUU graduate is 5th all-time in career points scored in program history (1,225 points), fourth all-time in free throw percentage (81.3 percent), and eighth all-time in 3-point field goal percentage (35.1 percent).Johnson has come to Cedar City with Sanders and attended Saint Mary’s from 2013-2017, graduating in 2017 with a bachelor’s degree in finance. June 13, 2018 /Sports News – Local Tracy Sanders Announces SUU Women’s Basketball Assistants Brad James Tags: Coaching Staff/Hailey Mandelko/Jay Johnson/SUU Women’s Basketball/Tony Giannotti/Tracy Sanders Written by
June 11, 2019 /Sports News – Local Utah State Football Inks Two Missionaries FacebookTwitterLinkedInEmailLOGAN, Utah – Utah State head football coach Gary Andersen announced Tuesday the addition of Cole Motes and Jack Rigby to the Aggie football program. Both players will serve two-year LDS Church Missions before enrolling at USU.Motes, a 6-foot-6, 240-pounder from Thatcher, Ariz. (Thatcher HS), earned Arizona Class 2A honorable mention all-state honors as both a tight end and defensive end as a prep senior. Motes, who is a 247Sports three-star recruit, helped Thatcher HS to three-straight state championships from his sophomore to senior seasons. Motes also earned all-region honors as a senior and was named his team’s Defensive Lineman of the Year. During his senior season, he caught eight passes for 158 yards (19.8 ypr) and two touchdowns on offense and recorded 48 tackles, which included 1.0 sacks and 9.0 tackles for loss, while adding one interception that he returned 44 yards on defense.Following his senior season, Motes was named the Thatcher High School Athlete of the Year as he also earned all-region and all-state honors in basketball, along with being named his team’s Player of the Year, and was a state qualifier in the discus and state runner-up in the shot put on the track & field team.Motes was also named his basketball team’s Player of the Year following his junior season as he earned honorable mention all-state and all-region accolades, along with qualifying for state in both the discus and shot put on the track & field team. Motes also earned all-region honors in basketball following his sophomore season.Rigby, a 6-4, 200-pound tight end from Kaysville, Utah (Davis HS), earned Utah Class 6A second-team all-state honors following his senior season as he caught 35 passes for 620 yards (17.7 ypr) and six touchdowns. As a prep senior, he had seven catches for 151 yards and three touchdowns against Clearfield HS and seven catches for 111 yards and one touchdown against Lone Peak HS. As a junior, he caught 14 passes for 152 yards (10.9 ypr). Rigby also played basketball at Davis HS. Written by Tags: Cole Motes/Jack Rigby/Utah State Aggies Football Robert Lovell