4,140 research outputs found
Pacific herring, Clupea harengus pallasi, studies in San Francisco Bay, Monterey Bay, and the Gulf of the Farallones, July 1982 to March 1983
Herring stocks were hydroacoustically surveyed and sampled in San Francisco Bay from November 1982 to March 1983. Twelve discrete herring schools were identified, all of which spawned between November 7 and February 23. One additional school was found in the Bay in March but showed no evidence of spawning. Total biomass estimate from
hydroacoustic surveys was 67,040 tons. Based on MRR biomass estimates from spawned egg counts, an additional 10,000 tons may have spawned in November and December without being detected hydroacoustically. The largest schools occurred in January and February. Hydroacoustic estimates of biomass for individual schools during the season ranged from
270 to 22,300 tons.
Sixty-seven samples, containing a total of 12,232 herring, were collected with variable mesh gill net and midwater trawl or obtained from the commercial roundhaul and gill net fisheries. In general, a trend was observed of decreasing mean size and age as the season progressed.
Schools spawning in November and December consisted primarily of 4-, 5-, 6-, and 7-yr-old fish. Schools sampled from January to March were predominantly 2-, 3-, 4-, and 5-yr-old herring. The 1978, 1979, and 1980 yr classes (ages 5, 4, and 3 yr) were strong, comprising up to 90% of the
samples. The 1981 yr class (2-yr olds) was relatively weak.
Abundant rainfall and resultant low salinity in San Francisco Bay surface waters apparently delayed or prevented herring from spawning in February and March.
A relationship may exist between relative abundance of young-of-the-year fish, as noted from midwater trawl samples collected by the Department's Bay-Delta Study, and the resultant year class strength of newly recruited
2-yr-old herring in San Francisco Bay's spawning stocks. (57pp.
Pacific herring, Clupea harengus pallasi, experimental roe-on-kelp open pound fishery studies in San Francisco Bay, December 1987 to February 1988
The experimental open pound herring roe-on-kelp (ROK) fishery was studied in San Francisco Bay from mid December 1987 to mid February 1988. Five different harvests were observed and sampled. A total of 19.7 tons of Macrocystis sp. kelp covered with herring eggs was processed during this period.
Kelp harvested from the Santa Barbara Channel Islands was
transported to San Francisco Bay for hanging on the pounds.
Weather conditions at the channel islands affected the condition and dimensions of the harvested kelp. Once suspended on the pounds in bay waters, the cut kelp deteriorated in 8 to 10 d. Based on our sampling, an average of 0.98 tons of kelp with a total blade surface area of 3031 m2 was suspended from each pound.
ROK was sampled at the shoreside processing facility. Densities of attached eggs ranged from light (less than three layers) to heavy (more than six layers) for the five different spawns. Egg coverage on each pound also varied; kelp towards the middle portion of the pound received heavier deposition of eggs. Average weight increase from egg deposition, per blade, was 780% with the kelp weighing an average of 12.2% of the total. An average 13.2% by weight was trimmed during processing. A multiplication factor of 0.206 should be used to convert individual roe herring allotments to ROK allotments.
Standard plastic totes containing processed ROK averaged 1783 lb total gross weight. Totes contained an average of 49.7% ROK by weight. Samples of roe-on-kelp increased an average of 10.9% in weight after brining during processing. (35pp.
Pacific herring, Clupea harengus pallasi, studies in San Francisco and Tomales Bays, April 1987 to March 1988
Herring schools were surveyed hydroacoustically and sampled in San Francisco Bay from late October 1987 to March 1988. Nine large schools (greater than 1000 tons) and four smaller ones were detected. Total acoustic biomass estimate, using a combination of echo integration and "visual integration" methods, was 71,110 tons. Improved acoustic calibration parameters resulted in this estimate being close to the spawn escapement-plus-catch estimate of 68,881 tons. However, the two biomass survey methods ere complementary and, when used together, provide a more accurate estimate of the spawning population than either method alone.
Eighty-two samples, containing a total of 16,316 herring, were collected with variable-mesh gill net, midwater trawl, or obtained from the roundhaul fishery. Mean body length decreased by more then 20 mm from the beginning to the end of the spawning season. Sex ratios favored males in November and December, while females were more abundant in February and March.
The 1982 through 1986 year classes (6- through 2-yr olds) contributed approximately 98% by weight and number to the total 1987-88 spawning biomass in San Francisco Bay. Herring year classes aged 7 and older each comprised no more then 1% of any school.
Above average recruitment occurred for the 1986 year class.
Recruitment may not be complete for some year classes until age 3 yr. This was particularly evident for the 1985 year clear. (72pp.
Pacific herring, Clupea harengus pallasi, studies in San Francisco Bay, April 1986 to March 1987
Herring schools were surveyed hydroacoustically and sampled in San Francisco Bay from late October 1986 to March 1987. Eight large schools (greater than 1000 tons each) spawned from December to February and seven smaller schools were detected throughout the spawning season. Total acoustic biomass estimate using a "visual integration" technique was 40,930 tons, and it was determined from spawn escapement and commercial landings that an additional 2240 tons were not detected. This is a slight increase from last season's total of approximately 42,200 tons. For the first time, biomass was also estimated using echo integration equipment. A total biomass was obtained of 33,050 tons, including herring not detected acoustically. This estimate must be considered preliminary and subject to revision after target strength of San Francisco Bay herring is determined.
Eighty-seven samples, containing a total of 13,125 herring, were collected with variable-mesh gill net and midwater trawl or obtained from the roundhaul and gill net fisheries. Mean body length (BL) of sampled herring decreased by about 20 mm from the beginning to the end of the spawning season. A combination of variable-mesh gill net and midwater trawl samples for a particular school closely approximates mean BL and age composition data from unbiased roundhaul samples.
Age-weight and age-length relationships were average to above average compared with those of the previous two seasons. The 1982 year class exhibited unusually good growth, with a mean BL of 202.8 mm for herring aged from stratified random samples.
The 1982 through 1985 year classes (5- through 2-yr olds)
contributed 97% by number and 95% by weight to the total 1986-87 spawning biomass in San Francisco Bay. Good recruitment has occurred during the past four seasons. The weak 1981 year class contributed little to the total biomass as 6-yr olds.
Average catch per tow of young-of-the-year (YOY) herring is a potential index of abundance for recruitment 18 months later as 2-yr olds. Estimated recruitment has only varied by 15% during the past three seasons and does not reflect the magnitude or trend in YOY catches in the bay. (85pp.
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Unlocking the Secrets of Ancient Writing. The Parallel Lives of Michael Ventris and Linda Schele and the Decipherment of Mycenaean and Mayan Writing
Catalogue of an exhibition conducted in conjunction with the Eleventh International Mycenological Colloquium held at the University of Texas at Austin in 2000. This program features brief histories of the CIPEM Mycenological conferences and PASP, followed by comparative retrospectives on both Michael Ventris, who deciphered Linear B, and Linda Schele, who performed a similar feat for Mayan glyphs.Classic
Maximal physiological responses to deep and shallow water running.
The maximal physiological responses to treadmill running (TMR), shallow water running (SWR) and deep water running (DWR) while wearing a buoyancy vest were compared in 15 trained male runners. Measurements included oxygen consumption (VO2 max), respiratory exchange ratio (RER) and heart rate (HR). Treadmill running elicited VO2 max and HRmax, which were higher than the peaks attained in both water tests (p < 0.01). VO2 peak averaged 83.7 and 75.3% of VO2 max for SWR and DWR respectively. Peak HR for SWR and DWR were 94.1 and 87.2% of the HRmax reached in the TMR. RER responses were similar between the three modalities. The observations suggest that the training stimulus provided by water is still adequate for supplementary training. While SWR is potentially an efficient method of maintaining cardiovascular fitness, it needs to be investigated further to establish if it is a viable technique for the injured athlete to employ
The role of motion analysis in elite soccer
The optimal physical preparation of elite soccer (association football) players has become an indispensable part of the professional game especially due to the increased physical demands of match-play. The monitoring of players’ work-rate profiles during competition is now feasible through computer-aided motion analysis. Traditional methods of motion analysis were extremely labour intensive and were largely restricted to university- based research projects. Recent technological developments have meant that sophisticated systems, capable of quickly recording and processing the data of all players’ physical contributions throughout an entire match, are now being used in elite club environments. In recognition of the important role motion analysis now plays as a tool for measuring the physical performance of soccer players, this review critically appraises various motion analysis methods currently employed in elite soccer and explores research conducted using these methods. This review therefore aims to increase the awareness of both practitioners and researchers of the various motion analysis systems available, identify practical implications of the established body of knowledge, while highlighting areas that require further exploration
Hyperpolarized Nanodiamond with Long Spin Relaxation Times
The use of hyperpolarized agents in magnetic resonance (MR), such as
13C-labeled compounds, enables powerful new imaging and detection modalities
that stem from a 10,000-fold boost in signal. A major challenge for the future
of the hyperpolarizaton technique is the inherently short spin relaxation
times, typically < 60 seconds for 13C liquid-state compounds, which limit the
time that the signal remains boosted. Here, we demonstrate that 1.1% natural
abundance 13C spins in synthetic nanodiamond (ND) can be hyperpolarized at
cryogenic and room temperature without the use of toxic free- radicals, and,
owing to their solid-state environment, exhibit relaxation times exceeding 1
hour. Combined with the already established applications of NDs in the
life-sciences as inexpensive fluorescent markers and non-cytotoxic substrates
for gene and drug delivery, these results extend the theranostic capabilities
of nanoscale diamonds into the domain of hyperpolarized MR.Comment: Supplemental Material available on reques
Adverse Effects of Cholinesterase Inhibitors in Dementia, According to the Pharmacovigilance Databases of the United-States and Canada.
This survey analyzes two national pharmacovigilance databases in order to determine the major adverse reactions observed with the use of cholinesterase inhibitors in dementia. We conducted a statistical analysis of the Food and Drug Administration Adverse Event Reporting System (FAERS) and the Canada Vigilance Adverse Reaction Database (CVARD) concerning the side effects of cholinesterase inhibitors. The statistics calculated for each adverse event were the frequency and the reporting odds ratios (ROR). A total of 9877 and 2247 reports were extracted from the FAERS and CVARD databases, respectively. A disproportionately higher frequency of reports of death as an adverse event for rivastigmine, compared to the other acetylcholinesterase inhibiting drugs, was observed in both the FAERS (ROR = 3.42; CI95% = 2.94-3.98; P<0.0001) and CVARD (ROR = 3.67; CI95% = 1.92-7.00; P = 0.001) databases. While cholinesterase inhibitors remain to be an important therapeutic tool against Alzheimer's disease, the disproportionate prevalence of fatal outcomes with rivastigmine compared with alternatives should be taken into consideration
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