bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population biology of northern shortfin squid (Illex illecebrosus) in the Northwest Atlantic Ocean and initial documentation of a spawning area
Authors: Hendrickson Lisa C 
Published: May 2004

Abstract
Growth, maturity, and age structure of the northern shortfin squid (Illex illecebrosus) population were characterized from samples collected during a stratified, random bottom-trawl survey conducted in May 2000. The survey was conducted on the continental shelf of the east coast of the US and utilized a commercial squid fishing vessel and standardized sampling protocols and gear. Statolith increment counts of 391 individuals, representing the full maturity spectrum from juveniles to mated females (34–250 mm), ranged in age from 69 to 215 d. Substantial variability in the precision of individual age estimates was encountered. The population consisted of a predominant winter cohort of maturing and mature squid (hatched during October–February, with a peak in January) and a spring cohort of juveniles (hatched during February and March, with a peak in March). Recruitment patterns to northern and southern fishing grounds are discussed. The first evidence of a spawning area, located on the continental shelf in the Mid-Atlantic Bight, is presented. Growth in length and weight was best described by a Gompertz model and a power model, respectively. The age range of mated females (115–215 d) indicated a shorter lifespan than expected based on maturity and age information for Newfoundland squid. A latitudinal cline in female size-at-maturity was evident, whereby maturity stages of squid in the southern part of the survey area were more advanced than those in the northern part. Also, females from US waters reach maturity and spawn at smaller sizes and younger ages than females from Newfoundland waters. The results suggest that females from the Mid-Atlantic Bight may exhibit faster rates of growth and maturation, and possibly a shorter lifespan, than their Newfoundland counterparts.
A risk assessment of the sustainability of the harvest of beluga (Delphinapterus leucas (Pallas 1776)) in West Greenland
Authors: Alvarez-Flores Carlos M. , Heide-Jørgensen Mads Peter 
Published: May 2004

Abstract
Risk assessments to assess the efficiency of management procedures to regulate removals of marine mammals have rarely been conducted. Using Bayesian methods, we conducted a risk assessment on a harvested beluga population off West Greenland. The population size in recent years was estimated to be 22% of the size in 1954. Results indicate that current catches are unsustainable and that continuation of this situation represents a 90% probability that the population will become extinct in 20 years. The analyses suggest that the harvest should be reduced to no more than 130 animals. Constant catch quotas represent a greater risk of depletion compared with catch limits that are a function of harvest rate and population size. An alternative gradual reduction schedule is proposed as a viable strategy, reducing the harvest in 5 years and adjusting the subsequent quota using a harvest rate of 0.5 of Rmax, with updates in the abundance. This analysis is presented as an alternative for cases where an immediate catch reduction is desirable but not feasible for marine mammal populations that appear vulnerable or in danger and where catch and abundance data are available.
Risk and strategy of fishers alternatively exploiting sea bream and tuna in the Gibraltar Strait from an efficiency perspective
Authors: Herrero Ines 
Published: May 2004

Abstract
While in the last few years interest in efficiency analyses has increased among fisheries economists, efficiency analyses have not been used so far to compare the profitability of alternative fisheries. We compared the profitability of the sea bream fishery and the tuna fishery, both operating in the South of Spain (Gibraltar Strait), based on an efficiency analysis and on a comparison of the efficient frontiers of the two fisheries. Results for 2002 show that, even if the sea bream is a higher-value species than tuna, the profitability of the latter is higher. However, sea bream still appears to be the target species of the fleet whereas the tuna fishery appears only as an alternative fishery. The key reason appears to be that the latter involves more risk than the former. The management of each fishing vessel seems related to the management strategy of the captain and to his assessments of risk.
Growth, maturation, and longevity of maturation cohorts of Norwegian spring-spawning herring
Authors: Beverton Raymond J.H. , Hylen Arvid , Østvedt Ole-Johan , Alvsvaag John , Iles Terence C. 
Published: May 2004

AbstractIn 1907, the Bergen Institute of Marine Research started regular sampling of scales and lengths from landings of mature Norwegian spring-spawning herring. The actual age of each fish when caught was recorded, and from the early 1920s also the age at which it spawned for the first time. The present analyses concern biological samples secured during the fishing seasons 1940–1964. Herring in this stock do not all reach maturity at the same age. A small proportion of any one year class matures at 3 years. The majority matures from the age of 4–7 years, and a small proportion of some year classes at 8 and even 9 years of age. Subsequent age composition and growth of each maturation cohort were followed throughout mature life after spawning for the first time. The maximum age was found to increase with age at maturation, rising to an asymptote of about 22 years. The von Bertalanffy parameter L∞ shows an increasing trend with age at maturation, while K decreases. There is no strict length threshold at maturation and the curve joining the length at which each maturation cohort reaches maturity is less steep than the growth curve itself over the range of maturation ages.The data suggest that fish in this stock spawn, on average, eight times during a period of their life history in which the mortality rate is independent of age. After these eight spawnings, at an age referred to in this paper as the hinge age, the mortality rate increases sharply. Thus, the adult life is divided into two phases, called here pre-senescent and senescent. The total mortality rates in the pre-senescent phase are relatively stable for all maturation cohorts 3–9, but there is some evidence of a trend towards higher mortality rates during the senescent phase for the youngest maturing fish. This trend is caused mainly by a reduced natural mortality in the fish that mature when older. These findings have interesting demographic implications. Additional mortality due to fishing will change the relative contribution of young and old maturation cohorts in the senescent phase, thus making it appear that natural mortality is dependent on the intensity of fishing. Consequently, for stock assessment, analysis on a cohort basis seems advisable.
The gastric properties of free-ranging harp (Pagophilus groenlandicus (Erxleben, 1777)) and hooded (Cystophora cristata (Erxleben, 1777)) seals
Authors: Christiansen Jørgen S. , Gildberg Asbjørn , Nilssen Kjell T. , Lindblom Charlotta , Haug Tore 
Published: May 2004

Abstract
The study of trophic relationships in seals is based primarily on prey remains recovered from the digestive tract or scats. Basic data on the gastric properties of seals are scarce and are considered to be important to interpret data from dietary studies of these animals. Hence, we examined the key properties of the gastric chyme post mortem (i.e. temperature, acidity, and the concentration of the proteolytic enzyme pepsin) in free-ranging harp (Pagophilus groenlandicus, n=40) and hooded (Cystophora cristata, n=41) seals. Seals displayed huge inter-individual variations in their gastric properties with ranges in temperature: 23.9–37.9°C, acidity: pH 1.16–7.34, and pepsin concentration: 11–1059 μg ml−1 chyme. The stomach weight and the mean values of gastric parameters revealed, however, significant species-specific differences. The stomach weight relative to body weight of hooded seal exceeded that of harp seal (t=13.77, d.f.=75, p<0.001). Furthermore, the gastric temperature and pepsin concentration were lower for harp (32.8°C and 75 μg ml−1) compared to that for hooded (35.3°C and 344 μg ml−1) seal. The reason for this disparity may be linked to the feeding mode and diet composition displayed by these seal species.
A Porcine Epistaxis Model: Hemostatic Effects of Octylcyanoacrylate
Authors: Singer Adam J. , McClain Steve A. , Katz Arnold 
Published: May 2004

OBJECTIVETo develop a standardized porcine epistaxis model and evaluate the hemostatic effects of octyl‐cyanoacrylate (OCA).STUDY DESIGN AND SETTINGTwenty‐four standardized full‐thickness wounds were created on the nasal septae of 7 pigs with a 4‐mm surgical punch. Wounds were randomized to no treatment or topical OCA before and after full heparinization. The rate of hemostasis, time to hemostasis, and number of applicators of OCA required to achieve complete hemostasis were determined and groups were compared with t tests and X2 tests.RESULTSComplete and sustained hemostasis was achieved in all wounds treated with OCA. The time to hemostasis was significantly shorter in the wounds treated with OCA vs those left to clot on their own (mean difference, 150 seconds; 95% CI, 92 to 209 seconds, P<0.001). None of the wounds required more than 3 applications of OCA.CONCLUSIONSWe describe a simple and reproducible animal epistaxis model and demonstrate that OCA is effective in achieving hemostasis in this model.
A preliminary evaluation of the sustainability of cassowary (Aves: Casuariidae) capture and trade in Papua New Guinea
Authors: Johnson Arlyne , Bino Robert , Igag Paul 
Published: May 2004

AbstractWildlife capture and trade for traditional use in Papua New Guinea has led to the extirpation of cassowary in some areas and increasing pressure for trade from areas where they remain. We tested a village‐based monitoring programme to evaluate sustainability of wildlife capture and trade by households in the Crater Mountain Wildlife Management Area. We monitored the type and number of wildlife species captured and traded. For the most heavily traded species, dwarf cassowary, we compared estimated annual offtake of live cassowary to maximum sustainable offtake and also compared change in hunter effort over time. We found that live offtake rates of 0.06–0.07/km2 were unsustainable in one village catchment and on the threshold of unsustainable use in another. Extirpation of cassowary will probably occur in the management area unless the location or quantity of the harvest can be restricted and the husbandry of captive birds improved. Results indicate that village monitoring of cassowary offtake is feasible when done in collaboration with outside, trained observers. Such monitoring should be encouraged as a means for landowners and management agencies to collectively evaluate the sustainability of the cassowary harvest in Papua New Guinea. This study provides an example of how scientists working with local communities in tropical forests can contribute to systematic monitoring and evaluation of wildlife offtake for sustainable use.
The outlook for pension contributions and profits in the US
Authors: MUNNELL ALICIA H. , SOTO MAURICIO 
Published: May 2004

The bear market that began in 2000 focused attention on two issues – pensions and profits. The initial pension problem was the big decline in value of individual 401(k) accounts. The profit issue was misconduct and stock options. In fact, there is another compelling issue involving both pensions and profits – the impact of the bear market on defined benefit pension plans.Plan sponsors have a projected benefit liability, which until recently was covered by the rise in asset values during the extended bull market. When stock values fell by 50 percent, sponsors for the first time in decades had to contribute to their pensions. But even without the decline in the stock market, sponsors of defined benefit plans were going to face increased pension contributions in the coming decade. The reason is a host of regulatory and legislative changes in the late 1980s that slowed or limited pension contributions.Our analysis suggests that in the absence of the stock market boom and the regulatory and legislative changes that reduced funding, the average firm's contribution to its pension plan would have been 50 percent higher during the 1982–2001 period; corporate profits would have been roughly 5 percent lower.The deferred contributions are coming due. The decline in the stock market and an ageing population imply that contributions would double from their current level. As the economy emerges from recession and the bear market draws to a close, firms and investors must be prepared to contend with a strong headwind from pension funding obligations that could slow the recover.
ON THE CHEMICAL COMPOSITION OF THE AXOPLASM OF SQUID GIANT NERVE FIBERS WITH PARTICULAR REFERENCE TO ITS ION PATTERN
Authors: Koechlin Bernard A. 
Published: May 2004

Investigations dealing with the determination of the major chemical constituents of the axoplasm of the giant nerve fiber of the squid are described. Particular emphasis has been placed on determining the components involved in acid-base balance.
It was found that 72 per cent of the total solids of axoplasm, representing 13.5 per cent of the wet material, are of relatively low molecular weight (dialyzable) and consist mainly of charged ionic or dipolar constituents.
Of the 520 micromoles per gm. of total base, 72 per cent are balanced by organic acids: aspartic acid (65 micro equivalents per gm.), glutamic acid (10 micro equivalents), fumaric and succinic acids (15 micro equivalents), a new polycarboxylic acid (35 micro equivalents), and isethionic acid, a biologically novel sulfonic acid (220 micro equivalents).
Besides potassium, sodium, small amounts of calcium, and magnesium there is a considerable fraction of organic (nitrogenous) base.
Other features of the chemical composition of squid axoplasm include a relatively high concentration of taurine (100 micro equivalents) and an ultraviolet absorbing substance possibly identical with N-methylpicolinic acid. The distribution of the phosphates, especially the concentration of ATP, has been investigated.
Specific techniques elaborated in connection with this study have been described and the biochemical implications of the analytical results are discussed.
THE FINE STRUCTURE OF THE RENAL GLOMERULUS OF THE MOUSE
Authors: Yamada Eichi 
Published: May 2004

Sections of mouse renal glomerulus fixed by perfusion with buffered osmium tetroxide solution have been studied with the electron microscope.
Four components are recognized in the mouse glomerulus: epithelium, basement membrane, endothelium, and intercapillary cell. The three cellular components all display in their cytoplasm mitochondria, Golgi bodies, endoplasmic reticulum, and uncharacterized vesicles.
The concepts of Hall, of Pease, and of Rhodin regarding the glomerular filtration surface are confirmed.
The epithelial cells are characterized by intricate, branching, interdigitating ridge-like processes or pedicels, the summits of which press against the urinary surface of the basement membrane, covering the glomerular capillary tuft almost completely except for narrow spaces about 200 to 300 A wide between the processes. These spaces are termed the epithelial filtration slits, and are bridged by a very delicate gossamer-like membrane about 30 A thick,—the filtration slit membrane.
The basement membrane is interposed everywhere between epithelial processes and endothelium, and between epithelial and intercapillary cells. The basement membrane of the filtration surface of the glomerular capillary has smooth surfaces and is about 800 A thick. It consists of three layers—a thick central lamina densa, appearing to have a very delicate felt-like structure, flanked on each side by thinner lamina rara externa and lamina rara interna. This membrane continues to the intercapillary space and makes a complicated sponge-work of varying thickness in which the intercapillary cells are enmeshed.
The endothelial cells are of moderate thickness in the nuclear region, but send out thin sheet-like extensions over the filtration surface. These extensions are about 300 to 400 A thick and are characterized by numerous round endothelial filtration pores about 500 to 1000 A in diameter.
The intercapillary tissue or mesangium is composed of the network of the basement membrane and the intercapillary cells.
The intercapillary cells, with characteristic fine fibrillar cytoplasm, make contact with epithelial and endothelial cells and are enmeshed within the network of the basement membrane. Rounded processes of intercapillary cells penetrate into the endothelial cell through the basement membrane, and may even perforate entirely through the endothelium. Such processes are called (after Zimmermann) the intracapillary colliculi.
In the endothelial cytoplasm close to the intracapillary colliculi are many dense endothelial juxtacollicular vesicles and caveolae.
The cell boundaries of the endothelial cell resemble terminal bars.
Some physiological speculations relating to glomerular structure are advanced.
The description of Zimmermann (54), based on a light microscope study, is confirmed in many respects.
STUDIES ON THE ENDOPLASMIC RETICULUM
Authors: Palade George E. 
Published: May 2004

A survey of a large number of different cell types has indicated the presence of a network of membrane-bound cavities (the endoplasmic reticulum) in the cytoplasm of all cell types examined, with the exception of the mature erythrocyte.
In its simplest form, encountered in seminal epithelia and in leucocytes, the reticulum consists mainly of interconnected strings of vesicles and appears to be randomly disposed in three dimensions.
Local differentiations occur within the endoplasmic reticulum of all the cell types studied.
The membrane limiting the cavities of the endoplasmic reticulum appears to be continuous with the cell membrane and the nuclear membranes.
LIGHT AND THE MUSCLE TONUS OF INSECTS THE HELIOTROPIC MECHANISM
Authors: Garrey Walter E. 
Published: May 2004

The tonus of the muscles of heliotropic insects is due chiefly to the action of light; it is markedly decreased in the dark. Each eye controls the tonus of a different group of muscles on both sides of the body. Different areas of each eye likewise are related to the tonus of different muscle groups, and the relationship is entirely analogous to that of the otic labyrinth of vertebrates. Asymmetrical conditions of muscle tension are produced by any procedure which establishes an unequal photochemical reaction in the two eyes, by difference in illumination, by partial or complete blackening of one eye, or establishing unequal sensitiveness in the two eyes. The unbalanced condition of muscle tonus expresses itself in unusual postures of the resting insects, and in movements in forced paths—circus motions when one eye has been blackened. These reactions vary directly with the intensity of the illumination, as shown not only by the variation in diameters of the circles, but also by the reactions of the insects on vertical surfaces and on the turntable.
The relation of the results of these experiments to the problem of heliotropic orientation is too obvious to require detailed discussion, which could only lead to a repetition of the description of the mechanism f heliotropism which Loeb has so clearly expounded. The experiments are so completely in accordance with Loeb's muscle tension theory of heliotropism, that they are tantamount to a complete proof of it.
A THEORY OF THE MECHANISM OF DISINFECTION, HEMOLYSIS, AND SIMILAR PROCESSES
Authors: Brooks S. C. 
Published: May 2004

1. The course of such processes as hemolysis is very largely dependent upon variations in resistance among the different individuals, and secondarily upon the course of the fundamental reaction.
2. The fundamental reaction may be either a simple process, or the expression of a complex series of changes whose rate is at all times governed by that of the slowest of the series. This might perhaps be regarded as another expression of the so called "Law of the minimum."
3. Unnatural assumptions would be requisite for the explanation of a resemblance between the course of such processes in general and that of a monomolecular reaction.
4. The supposition that such a general resemblance exists is not supported by the available evidence.
5. The independent determination of either the nature of the fundamental reaction, or the type of the variation curve for the particular case under observation, will further our knowledge of the nature of such processes and lead to a far deeper insight into the nature and reactions of living matter.
COMPARATIVE STUDIES ON RESPIRATION
Authors: Osterhout W. J. V. 
Published: May 2004

A series of investigations on respiration with improved quantitative methods has been commenced. The first of these are here described. They show that when anesthetics are employed in sufficient concentration to produce any result, plants show a rise in the rate of respiration which is followed by a fall. In the animals studied, the rise (found in higher concentrations only) was preceded by a temporary fall which is not entirely due to lowering of muscular activity or tonus. In lower concentrations the effect on animals was merely a decrease of respiration.
The results of all the investigations are opposed to the theory of Verworn.