bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of ophthalmic Nd:YAG laser energy on intraocular lenses after posterior capsulotomy in normal dog eyes
Authors: Beale A. Brady , Salmon Jacklyn , Michau Tammy M. , Gilger Brian C.
Published: August 2006

Objective  To determine Nd:YAG laser energy requirements for posterior capsulotomy and intraocular lens (IOL) damage threshold for foldable acrylic IOLs as compared to traditional polymethylmethacrylate (PMMA).

Materials and procedures  Four groups of five–six fresh canine cadaver eyes were used in this study. The groups included (1) unaltered eyes (2) aphakic eyes (3) eyes implanted with PMMA IOLs, and (4) eyes implanted with acrylic IOLs. Laser energy was delivered to the posterior capsule in grid fashion for 10 sites each of five levels of laser energy ranging from 0.5 mJ to 9 mJ. Number of successful capsulotomy sites was recorded based on slit‐lamp observation. Sites of IOL damage were evaluated using scanning electron microscopy (SEM). Statistical analysis of number of capsulotomies and IOL defects per laser energy level was conducted among and between groups using anova with Tukey's HSD test.

Results  When comparing groups (a) including all energy levels (n = 25) and (b) by specific energy levels (n = 5), there was no significant difference (P < 0.05) in number of successful capsulotomy sites between IOL types. The 50% incidence threshold for successful capsulotomy was 2.74 mJ for acrylic IOLs and 2.64 mJ for PMMA IOLs. Energy‐dependent damage to both types of IOL was detected for medium, high‐medium, and high laser energy. Calculated 50% damage threshold was 4.9 mJ for acrylic IOL and 5.7 mJ for PMMA IOL. Damage to the IOL varied subjectively between IOL type, but there was no significant difference in number of defects caused, with the exception of high‐medium energy.

Conclusions  Both posterior lens capsules and IOLs were disrupted in an energy‐dependent manner with minimal difference in number of capsulotomy sites or damage to the IOL between acrylic and PMMA IOLs. A therapeutic margin between capsulotomy threshold (2.6–2.7 mJ) and IOL damage threshold (4.9–5.7 mJ) was determined to reliably achieve capsulotomies with minimal IOL damage for both acrylic and PMMA IOLs in normal canine cadaver eyes.
Ultraviolet irradiation up‐regulates telomerase transcription and activity in lens epithelial cells
Authors: Colitz Carmen M. H. , Barden Curtis A. , Lu Ping , Chandler Heather L.
Published: August 2006

Purpose  Ultraviolet irradiation (UVR) increases telomerase activity in various cell types including skin, a sun‐exposed organ. The lens is also continually exposed to UVR and we hypothesized that lenses exposed to UVR would have increased telomerase activity, with up‐regulated TERT and TR, the two main components of the telomerase holoenzyme. To evaluate whether the cornea would protect lenses from such changes, whole globes, as well as isolated lenses, were exposed to UVR, and lenses were evaluated for changes in telomerase activity.

Methods  There were three parts to this project. The first part of this experiment evaluated freshly harvested normal adult canine lenses exposed to 0, 300, 600, or 1200 J/m2 UVR, and then allowed to recover for 1, 2, 3 and 4 h. Since only 600 J/m2 UVR increased telomerase activity, four more postexposure recovery time‐points for this UVR dose were evaluated: 10 min, 30 min, 8 h and 24 h. The second part of this experiment used freshly enucleated whole canine globes exposed to 0, 50, 100, 150, 300, 600 or 1200 J/m2 and incubated overnight; lens epithelial cells (LEC) were evaluated for telomerase activity. The third part evaluated lenses that were exposed to 0 or 600 J/m2 UVR, and then allowed to recover for 8 and 24 h, before TERT and TR mRNA levels were measured.

Results  Isolated lenses exposed to 600 J/m2 UVR had significantly higher telomerase activity than unexposed controls and other UVR doses, at all time‐points except 24 h postexposure. Lenses from whole globes exposed to UVR showed a dose‐dependent increase in telomerase activity except at 50 J/m2 and 1200 J/m2. Isolated lenses exposed to 600 J/m2 UVR and then allowed to recover for 8 and 24 h significantly up‐regulated TERT and TR mRNAs compared to unexposed control lenses.

Conclusions  Telomerase activity is regulated at both the transcriptional and post‐translational levels in canine LEC. Previous work in our laboratory showed dose, time, and age‐dependent changes in telomerase activity in the lens. The present study showed that TERT and TR mRNA transcription was increased for up to 24 h following an acute dose of UVR. Both telomerase activity and TERT and TR mRNA levels were elevated until 24 h post‐UVR exposure, TERT in combination with TR functions in proliferation‐related telomerase activity, but TERT alone has an anti‐apoptotic function and its up‐regulation may protect LEC from the acute effects of UVR. We are continuing to evaluate the mechanisms by which telomerase is regulated in normal and cataractous LEC.
Principles and practical aspects of healthful school vending
Authors: Higgs J. , Styles K.
Published: August 2006

Summary  Implementation of the Govemments’ new school food standards from September 2006 across English schools has major implications for traditional school vending practices. Although vending has been viewed for several years as an income generator for the school, the potential detrimental influence that the contents of most machines may be having on children’s health, either directly (from consumption of the contents), or indirectly (from the messages they convey) has only recently become a high profile issue. The Health Education Trust has always held the view that vending per se is not the issue, it is the contents of the school machines that require changing. This paper summarises the recent work managed by the Trust, from the pilot studies in schools to developing a rationale for healthy vending operations. This work has indicated that there is much potential for healthy vending in schools, the pupils like it and healthy profits can still be made, provided the vending operation is well managed.
The Risk of Historical Artefacts in Travel: The Construction of Risk in the International Travelling Exhibition
Authors: LAI CHIA‐LING
Published: August 2006

Abstract  This article interrogates the risk of historical artefacts in travel, emphasising especially on the construction of the risk of boundary‐crossing when museum exhibits travel abroad through “outbound” international travelling exhibitions. This follows the history of a controversial exhibition, the “Splendour of Imperial China”– held in 1996 that travelled from the National Palace Museum in Taipei which is renowned for its abundant and unique Chinese art collection to one of the most prominent museums on the global stage – the Metropolitan Museum of Art in New York. Drawing upon Mary Douglas's analysis of danger/risk and classification, this paper argues that the risk within the “outbound” international travelling exhibition is less ontological than constructed. Often the controversy over the risk re‐delineates the boundary between “us” and “them”. This article, first of all, examines the power‐laden relationship, regulated by the struggle of the global museum field, when museum experts at home and abroad co‐write the risk of an exhibition's travel in the language of insurance calculation. Second, it analyses the laymen's protesting discourses against the historical artefacts' overseas travel through outbound international travelling exhibition. The protest which appropriated the “keeping‐while‐giving” logic of exchange, and backed up with both national sentiments and international symbolic sources, rendered the exhibition a hot potato. Finally, it interrogates how the settled outbound travelling exhibition actually renders the museum collection reclassified and revalorized according to their suitability for overseas travel.
Private Sector Foreign Investment and the Environment
Authors: Esty Daniel C.
Published: August 2006

The industrialization of the developing world is now and will continue to be predominately financed by private capital rather than bilateral or multilateral assistance. To the extent that associated pollution problems spill across national boundaries, this industrialization can no longer be viewed by the developed world as simply an investment opportunity but must also be seen as a potential source of pollution harm. Just as governments have an interest in investments made within their borders, the way in which capital is invested in developing countries has become a legitimate interest of policy makers in developed countries. Governments can advance their international environmental interests by direct assistance, and by providing incentives to the private sector. The private sector can assist in the establishment of environmental guidelines, labelling criteria, and investment guidelines. However, to be effective these mechanisms must be co‐ordinated transnationally.
Environmental Covenants Between Government and Industry A Dutch NGO's Experience
Authors: Biekart Jan Willem
Published: August 2006

Samenvatting

Uit het Nationaal Milleubeleidsplan blijkt dat de regering voor wat betreft de uitvoering van het milieubeleid voor industrie sterk inzet op de koers van zelfregulering, waarin convenanten een grote rol spelen. De nu bestaande convenanten hebben betrekking op produkten, industriële produktieprocessen of energiegebruik in uiteenlopende bedrijfstakken. Nu de eerste resultaten van de convenantenbenadering duidelijk worden is het tijd geworden om vanuit de optiek van de milieubeweging een kritische blik te werpen op de rol van convenanten bij de uitvoering van het milieubeleid. De ervaringen van de Nederlandse milieu‐organisaties met convenanten wisselen sterk, al naar gelang de kenmerken van een bepaald convenant. Aan de hand van een groot aantal voorbeelden worden uiteindelijk drie stellingen geformuleerd. De eerste stelling is dat de convenanten een toegevoegde waarde hebben mits ze gebruikt worden als voorloper van of ter uitvoering van milieuwetgeving. De tweede stelling is dat convenanten onaanvaardbaar zijn als zij zich onttrekken aan de democratische controle door derde partijen. Dit is eigen aan convenanten, omdat het privaatrechterlijke contracten zijn. Toch hoeft dit geen probleem te zijn als de eerste stelling in het oog wordt gehouden en convenanten (als instrument) geen basis krijgen in de milieuwetgeving. Tenslotte wordt betoogd dat convenanten slechts een instrument zijn binnen de filosofie van zelfregulering door bedrijven. Willen overheid en bedrijven geloofwaardig zijn hierin, dan dienen ook andere instrumenten uit dit bereik te worden ingezet, om te komen tot een goede synergic Dergelijke instrumenten zijn bijvoorbeeld het milieujaarverslag en goede wetgeving op het gebied van milieuaansprakelijkheid.
Promoting the Use of Lifecycle Assessment in Product and Service Design and in Public Policy
Authors: Hindle P. , de Oude N.T. , Osterlof P. , De Smet B.
Published: August 2006

Ľécobilan est une technique qui permet ľétude des ressources nécessaires aux produits et services ainsi que celle des rejets associés à ces mêmes produits et services. La législation Européenne reconnaît ľimportance et la valeur de cet outil scientifique. La méthodologie nécessaire pour inventorier ľutilisation des resources et la liste des rejets est bien définie et est de plus en plus utiliseé. A ce jour, il n'existe pas encore de méthodologie reconnue pour passer du stade du bilan à celui de ľimpact environmental.

Un nombre de scientifiques travaillent àľ amélioration des techniques utilisées dans les écobilans afin ?en accrître ľutilité aussi bien pour celui qui développe des produits et services que pour le législateur. SPOLD (Society for the Promotion of Lifecycle Assessment Development) réunit un grand nombre de ces scientifiques venant ?horizons aussi différents que ľindustrie, la consultance et ľuniversité. Le travail accompli par SPOLD afin de mettre sur pied des bases de données pour écobilans, accessibles à tous, est décrite.

Ľécobilan n'est évidemment pas le seul outil environnemental qui peut être utilisé pour optimiser, ?un point de vue environmental, produits et services. Le travail accompli par SPOLD pour accrître la compréhension des écobilans et développer leur utilisation est également donné.
Legal Framework for Environmental Co‐operation in Latin America: An Overview
Authors: Herrera Alfonso Ascencio , Pevato Paula M
Published: August 2006

Sumario

América Latina constituye una región que ha dado expresión juridica, de conformidad con los principios del Derecho International, a la necesidad de cooperar en materia ambiental. En este sentido, los Estados que conforman la región han confeccionado una serie de tratados de carácter bilateral y subregional a fin de proporcionar un sustento legal a la cooperación en este rubro. Los comprornisos asumidos a través de los documentos que emanaron de la Conferencia de Rio d e Janeiro en 1992, cuentan con el reconocimiento de su validez por parte de los Estados latinoamericanos. Ante todo, América Latina fundamenta sus acciones en el Bmbito ambiental mediante: consultas a nivel politico; cooperación en las esfaras legal y politica; y, sobre la firme convicci6n que la cooperación ambiental es solo un aspecto, entre varios, que componen la prioridad de lograr el desarrollo sostenible.
PHYSICAL GEOGRAPHY OF TROPICAL LATIN AMERICA: THE SPATIAL AND TEMPORAL HETEROGENEITY OF ENVIRONMENTS
Authors: Zimmerer Karl S. , Langstroth Robert P.
Published: August 2006

For the past 40 years, studies of physical geography in tropical Latin America have concentrated on the spatial and temporal diversity of biophysical environments and biota. Environmental heterogeneity arises from historical and present‐day interaction between climatic, geomorphologic, edaphic, and biogeographic systems. Recent research emphasizes three major themes involving these systems: Quaternary climate change; human‐altered biophysical environments; and geomorphologic activity. Findings on these themes are evaluated with respect to the tropical highlands, the tropical lowlands and related extra‐tropical areas. Research on physical geography in Latin America promises numerous contributions toward a better understanding of environmental conservation.
TAIWANESE FOREIGN DIRECT INVESTMENT AND TRADE WITH THAILAND
Authors: Kang‐hung Chang , Thornson Curtis N.
Published: August 2006

Thailand has one of the fastest growing economies in the world, and an important factor contributing to this phenomenal growth is foreign direct investment (FDI). Taiwan's investment in Thailand, led by small and medium sized companies in labour intensive and relatively low technology industries, has increased dramatically since 1986. While Western multinational companies have been interested in using FDI to expand their markets in the host country, Taiwanese FDI — in a pattern similar to Japanese FDI of the 1970s — has been taking place in selected developing countries to lower production costs and export manufactured products to third country markets. Taiwan's exports to Thailand have also shown a marked increase since the Taiwanese government allowed large scale FDI in 1986. Although small at the global scale, Taiwanese investment in Thailand has contributed to an increasingly integrated East Asian economy.
VARIABILITY IN THE CHARACTER OF HONG KONG RAINY SEASONS
Authors: Jackson I.J.
Published: August 2006

Using a range of rainfall variables, rainy seasons in Hong Kong in each of 99 years have been characterised and classified into 11 groups. Many of the correlations between variables are low, indicating the need for a multivariate approach to classification. The main characteristics of each group of seasons, their frequencies of occurrence and a small number of sequences of types which are unlikely to have occurred by chance are presented. Characteristics of the rainfall variables and aspects of their temporal variations are also presented.
THE ENVIRONMENTAL DIMENSIONS OF STRUCTURAL ADJUSTMENT PROGRAMMES: MISSING LINKS TO SUSTAINING DEVELOPMENT
Authors: Kendie S. B.
Published: August 2006

The implementation of structural adjustment programmes has not paid sufficient attention to the environmental effects of prescribed reforms. Agriculture is often the largest sector contributing significantly to the generation of export revenue and the gross domestic product in many adjusting countries, including Ghana. Structural adjustments in this sector aim at removing constraints to productivity. In Ghana, these reforms include producer price increases, market liberalisation and exchange rate reforms. This paper examines the environmental effects of raised farmgate prices for cocoa and cotton cultivation. It argues that these policies have encouraged agricultural extensification, particularly given the main type of farming (slash and burn agriculture) practised in Ghana. Environmental degradation is occurring in many areas. Furthermore, cuts in public expenditure and the institution of cost‐recovery schemes for previously subsidised services such as rural water supply may reduce farmers’ disposable incomes and their ability to pay for these services. Consumption of unsafe water exposes farmers to preventable water and hygiene related diseases which, given the high cost of medical services, may worsen poverty and further encourage agricultural extensification.
FALLOW AND FERTILITY UNDER SUBSISTENCE CULTIVATION IN THE PAPUA NEW GUINEA HIGHLANDS: II. SOIL FERTILITY
Authors: Sillitoe Paul
Published: August 2006

The farming regime of the Wola people of Nipa District in the Southern Highlands Province of Papua New Guinea features the cultivation of some land semi‐permanently under non‐perennial crops within the broad context of a swidden regime. An investigation of the fertility status of the soils they cultivate —Inceptisols variably affected by falls of volcanic ash — suggests how these farmers avoid the soil constraints that might otherwise prompt long‐term fallowing of sites under such a tropical subsistence agricultural regime. While organic matter and the elements N and K all decline significantly with time under cultivation, they settle at new equilibria which may not signify deficiencies for some crops. The other major nutrient P also falls significantly over time, although levels are relatively low throughout. Other nutrients show no significant variation. These findings comply with the wide variety of crops observed under cultivation early in the life of gardens, followed later by a virtual sweet potato mono‐crop. This crop is able to continue yielding adequately in the long term, following a decline in nutrient availability, notably because they remain in favourable ratios for tuberisation and because of its tolerance of low P conditions.
THE HISTORICAL GEOGRAPHY OF HONG KONG INVESTMENTS IN THE ASEAN REGION
Authors: Yeung Henry Wai‐chung
Published: August 2006

Conventional studies of “Third World multinationals” tend to focus on their recent origins. This paper argues that the transnational operations of Hong Kong firms have had a long tradition originating in its Overseas Chinese networks and in the colonial experience of many Southeast Asian countries. Based on secondary and primary data, this paper takes a historical view to describe how the ASEAN operations of Hong Kong transnational corporations (HKTNCs) and their foreign direct investment (HKFDI) have evolved over more than a century to become one of the most important economic players in the ASEAN region. Four phases of their historical development are benchmarked in this paper. Before World War II, HKTNCs in the commercial and banking sectors had a notable presence in the region. It was, however, in the post‐war period that HKTNCs and their FDI flows flourished. During the period 1945–69, industrialisation took off in Hong Kong and this led to the expansion of manufacturing HKTNCs into the ASEAN region. The real zenith of outward investment from Hong Kong was the 1970s and 1980s so that in the 1990s Hong Kong has become one of the largest investors in Indonesia, Singapore and Thailand.
Progressive loss of SIRT1 with cell cycle withdrawal
Authors: Sasaki Tsutomu , Maier Bernhard , Bartke Andrzej , Scrable Heidi
Published: August 2006

Sir2 is an NAD+‐dependent deacetylase that regulates lifespan in yeast, worms and flies. The mammalian orthologs of Sir2 include SIRT1 in humans and mice. In this study, we analyzed the level of SIRT1 in human lung fibroblasts (IMR90) and mouse embryonic fibroblasts (MEFs) from mice with normal, accelerated, and delayed aging. SIRT1 protein, but not mRNA, decreased significantly with serial cell passage in both human and murine cells. Mouse SIRT1 decreased rapidly in prematurely senescent (p44 Tg) MEFs, remained high in MEFs with delayed senescence (Igf‐1r–/–), and was inversely correlated with senescence‐activated β‐galactosidase (SA‐βGal) activity. Reacquisition of mitotic capability following spontaneous immortalization of serially passaged wild‐type MEFs restored the level of SIRT1 to that of early passage, highly proliferative MEFs. In mouse and human fibroblasts, we found a significant positive correlation between the levels of SIRT1 and proliferating cell nuclear antigen (PCNA), a DNA processing factor expressed during S‐phase. In the animal, we found that SIRT1 decreased with age in tissues in which mitotic activity also declines, such as the thymus and testis, but not in tissues such as the brain in which there is little change in mitotic activity throughout life. Again, the decreases in SIRT1 were highly correlated with decreases in PCNA. Finally, loss of SIRT1 with age was accelerated in mice with accelerated aging but was not observed in long‐lived growth hormone‐receptor knockout mice. Thus, as mitotic activity ceases in mouse and human cells in the normal environment of the animal or in the culture dish, there is a concomitant decline in the level of SIRT1.
Progesterone‐Modulated Phosphatidylserine Externalization in Apoptosis and Activation of Jurkat Cells
Authors: Mourdjeva Milena , Popova Zlatka , Kyurkchiev Dobroslav , Kontinopoulou Katerina , Altankova Iskra , Kehayov Ivan , Kyurkchiev Stanimir
Published: August 2006

Problem  During pregnancy the elevated levels of progesterone (Pg) have immunomodulating effects. It is important to follow‐up Pg effects on basic biological processes at cell level as apoptosis and activation which was the aim of this study.

Methods of study  Jurkat cells cultured in the presence or absence of Pg were used as a model system. Apoptosis was induced by H2O2 and activation by phorbol myriastate acetate. The induced changes in the phosphatidylserine (PS) externalization and cell surface CD69 expression were followed by fluorescence‐activated cell sorter and immunofluorescence.

Results  After the induction of apoptosis PS externalizes in 52.3% of Jurkat cells. Cells cultured with Pg show tendency to a decrease of PS positive cells (42%). The opposite effect is observed in activated cells – PS externalization increase from 33.8% of control cells to 40.1% of Pg‐treated cells.

Conclusions  These findings would suggest that by increasing activation and decreasing apoptosis Pg could regulate local immune system during pregnancy.
In vitro evaluation of endodontic debris removal as obtained by rotary instrumentation coupled with ultrasonic irrigation
Authors: Passarinho‐Neto Jarbas Gonçalves , Marchesan Melissa Andréia , Ferreira Rafael Brandão , Silva Ricardo Gariba , Silva‐Sousa Yara Teresinha Correa , Sousa‐Neto Manoel D.
Published: August 2006

The cleaning capacity of rotary Ni‐Ti instrumentation using Profile GT files, coupled with irrigation energised by ultrasound, was evaluated. Thirty‐six human mandibular incisors were instrumented in vitro using the crown‐down technique with the Profile GT system to 1 mm from the anatomical apex to a size 30.04 taper file. The instrumented teeth were then divided randomly into four groups where various final irrigations were used: Group I: 100 ml of 1% NaOCl with a Luer–Lok syringe (control group); Group II, Group III and Group IV: final irrigation with 100 ml of 1% NaOCl energised by ultrasound for 1, 3 and 5 min, respectively. After biomechanical preparation, the apical thirds of the roots were submitted to histological processing and examination. The specimens were analysed at 40× magnification and the images submitted to morphometric analysis with an integration grid. anova showed a statistically significant difference (P < 0.01) between the irrigation techniques. Group I (Luer–Lok syringe) showed the highest percentage of debris (35.81 ± 4.49) and was statistically different from the other groups energised by ultrasound: Group II (27.28 ± 4.49), Group III (24.39 ± 5.72) and Group IV (18.46 ± 5.25). It was concluded that rotary instrumentation using Ni‐Ti files associated with final irrigation of 1% NaOCl energised by ultrasound leads to better debris removal from the apical third of mesio‐distally flattened root canal.
SENSORY BIOPHYSICS OF MARINE MAMMALS
Authors: Watkins William A. , Wartzok Douglas
Published: August 2006

Abstract

The underwater existence of marine mammals has encouraged a variety of special biophysical adaptations to their environment. Their sensory and communication systems reflect the transmission properties of sea water. For example, vision is keen in spectra that penetrate water best, vocalization is broadband and used at the frequencies that appear to fit their activities best—the differences in sensory use match the intriguing variety of behavior observed for each species. To date most of the observations of animal interactions with their marine environment have dealt with sound. There has been some work on vision and studies are underway to determine animal sensitivities to hydrodynamic pressure, chemical traces and magnetic fields. The species that have been recorded to date are listed and vocalizations are generally compared. Methods for observation of sensory mechanisms are noted along with a discussion of other aspects of marine mammal biophysics including vibrissal sensation and the biophysics of movement in a fluid environment.
GROWTH LAYER GROUPS (GLGs) IN THE TEETH OF AN ADULT BELUKHA WHALE (DELPHINAPTERUS LEUCAS) OF KNOWN AGE: EVIDENCE FOR TWO ANNUAL LAYERS
Authors: Goren Arthur D. , Brodie Paul F. , Spotte Stephen , Ray G. Carleton , Kaufman H. W. , Gwinnett A. John , Sciubba James J. , Buck John D.
Published: August 2006

Abstract

Growth layer groups (GLGs) were counted in teeth from an adult male belukha whale (Delphinapterus leucas) that had lived for 23 yr in captivity and was estimated to have been 14 mo at capture. As defined here, GLGs are repeating areas of alternating opaque (denser) and translucent (less dense) dentin or cementurn, or nodes at the dentin‐cementum interface. A GLG involves at least one change from opaque to translucent, dense to less dense or ridge to groove, but may be further subdivided by incremental growth layers or laminations. Teeth were prepared by two techniques. Thick sections (longitudinal half sections) were examined with a dissecting microscope under reflected light. Thinner cross and longitudinal sections were x‐rayed and the plates scanned with a microdensitometer. Scanning electron photomicrographs were prepared from thick sections, but SEM proved to be the least useful technique. Counts of GLGs were variable because the laminations were numerous and some surface layers had been lost from wear. Thick‐ and thinner‐section techniques gave comparable results, and approximately 40 GLGs were counted consistently. Although captive environments are less variable than natural ones, our findings are further evidence that belukhas in the wild deposit more than one—and probably two—GLGs per year.
EXTERNAL MORPHOLOGY AND PIGMENTATION OF THE VAQUITA, PHOCOENA SINUS (CETACEA: MAMMALIA)
Authors: Brownell Robert L. , Findley Lloyd T. , Vidal Omar , Robles Alejandro , Silvia Manzanilla N
Published: August 2006

Abstract

The vaquita, Phocoena sinus, is a porpoise in the family Phocoenidae that lives only in the Gulf of California. The external appearance of P. sinus was unknown until 13 fresh specimens were recently examined. The most obvious morphological feature distinguishing P. sinus from its two congeners is the proportionately higher dorsal fin. The most striking features of the pigmentation pattern are the large black eye patches and the black upper and lower lip patches. In both areas, the pigmentation contrasts sharply with the surrounding light gray coloration. The total lengths of the specimens ranged from 70.3 cm (a neonate) to 143.5 cm (an adult female).
CORNEAL SURFACE PROPERTIES OF TWO MARINE MAMMAL SPECIES1
Authors: Dawson William W. , Schroeder J. Pete , Sharpe Scott N.
Published: August 2006

Abstract

Compared to the anterior surface of the normal human cornea, all Tursiops showed pronounced random, local curvature changes typical of old keratitis and scarring. Comparable but less severe findings apply to Zalophus. These irregularities were superimposed on the mild regular astigmatism of the spoon‐shaped Tursiops cornea (mean central power is 26.8 D, SD = 3.8, N = 82). All Zalophus corneas showed no reliable regular astigmatism (overall mean power is 21.7 D, SD = 4.4, N = 53) but exhibited a flat, circular region about 6.5 mm in diameter along the nasal aspect of the horizontal meridian. Refraction through this cornea1 region showed aerial emmetropia, which accounts for equivalent marine and aerial visual resolution in this species.
THE PHYSIOLOGICAL TRANSITION FROM FASTING TO FEEDING IN WEANED ELEPHANT SEAL PUPS
Authors: Condit Richard S. , Ortiz C. Leo
Published: August 2006

Abstract

We studied energetics and food utilization in young elephant seals as they were first introduced to solid food following their long post‐weaning fast. Using radioactive tracer techniques, we monitored changes in body composition, protein metabolism, and metabolic rate during fasting and initial feeding. In fasting animals, fat stores supplied nearly all energetic requirements. In feeding animals, 49% of protein ingested was retained as body tissue, allowing protein mass to increase. Body fat was lost at rates comparable to rates in fasting animals and continued to fuel the bulk of metabolism. Weight loss was arrested when animals consumed 786 g/d, or 40 kcal/kg0.75/d, which was far less than their metabolic rates (63–206 kcal/kg0.75/d). Surprisingly, the young seals were able to maintain weight and store protein while energy intake was below metabolic needs. This was possible because animals gained weight as water; they retained wellhydrated proteinaceous tissue while losing poorly‐hydrated adipose tissue.
THE MICROSCOPIC AND IMMUNOHISTOLOGIC ANATOMY OF THE ENDOCRINE PANCREAS OF PYGMY AND DWARF SPERM WHALES (KOGIIDAE)
Authors: Brown Eileen Dellner , Bossart Gregory D. , Reynolds John E.
Published: August 2006

Abstract

Histologic studies of pancreatic tissues of one pygmy sperm whale, Kiogia breviceps, and one dwarf sperm whale, K. simus, demonstrated rather typical exocrine pancreatic anatomy. Peroxidase‐antiperoxidase (PAP) techniques determined that the cell composition of the islets of Langerhans resembled that of other mammals. Within islets, cells secreting insulin (B‐cells) and glucagon (A‐cells), were clearly demonstrated, but, surprisingly, isolated A‐ and B‐cells were also found among pancreatic acinar cells. PAP techniques demonstrated the presence of neuron‐specific enolase within islets, but failed to provide a sufficiently clear reaction to demonstrate the presence of somarostatin‐producing D‐cells. No positive PAP reaction for serotonin occurred.
TRACE METALS AND METHYL MERCURY: ASSOCIATIONS AND TRANSFER IN HARP SEAL (PHOCA GROENLANDICA) MOTHERS AND THEIR PUPS
Authors: Wagemann R. , Stewart R. E. A. , Lockhart W. L. , Stewart B. E. , Povoledo M.
Published: August 2006

Abstract

Milk samples from the stomachs of harp seal pups were analysed for Cu, Zn, Se, Cd and Hg, as were liver, kidney, and muscle from mother‐pup pairs. Tissues were also analysed for MeHg. Milk contained, in addition to essential trace metals, Cd and Hg (57 ng/g and 6.5 ng/g respectively).

Pups had mercury in all three tissues. The percent methyl mercury in liver of pups was higher than in liver of mothers. Mercury in muscle was mostly methyl mercury in both mothers and pups. Total mercury in liver of mothers but not pups was correlated positively with selenium. Estimates of ingested mercury by pups indicated they had acquired most of their mercury during gestation.

Although mothers had cadmium in liver and kidney, it was not detected in tissues of pups. Cadmium did not transfer across the placenta, while mercury did. Tissue concentrations of Cu and Zn were higher in pups than mothers. The presence of metallothionein in pup tissues was postulated.

A strong positive correlation of copper and selenium between mothers and pups indicated transfer of these elements from mother to pup in direct proportion to their concentrations in maternal liver and kidney.
AERIAL CENSUS OF PACIFIC WALRUSES IN THE CHUKCHI SEA, 1985
Authors: Gilbert James R
Published: August 2006

The U.S. Fish and Wildlife Service conducted a survey of the walruses in the pack ice of the Chukchi Sea between 16 September and 2 October 1985, as part of a joint effort with the Soviet Union to estimate the size of the Pacific walrus population. American observers conducted censuses from two aircraft along randomly selected north–south lines over the pack ice. The observers counted walruses within a constant viewing angle that corresponded to a total strip width of 1.38 km at an altitude of 152 m.

In nine days of flying, 15,312 walruses were observed, of which 10,140 were on 5,764 km2 of census strips. Few walruses were observed east of 161°W longitude or west of 170°W longitude, hence the census effort was stratified. Walrus concentrations between 161° and 170° shifted slightly westward during the 2‐wk duration of the censuses. The differences among days in observed walrus density were due to changes in the numbers of walruses on the ice within 37 km of the ice edge. The number of observable walruses in pack ice of the eastern Chukchi Sea was estimated to be 62,177 (SD = 19,480), based on censuses conducted on 29 and 30 September and 1 October. At that time there were also at least 15,238 in Bristol Bay, Bering Sea. The Soviets counted 39,572 on the shores of the western Chukchi and Bering seas and estimated 115,531 in pack ice of the western Chukchi Sea. Summing U.S. and Soviet estimates, the total population of Pacific walruses in 1985 was 232,518. This number was comparable with earlier estimates from censuses conducted jointly by the U.S. and the Soviets. However, information on fraction hauled out, segregation, and movements is needed for more precise estimates.
GLUCOSE KINETICS IN NEONATAL ELEPHANT SEALS DURING POSTWEANING APHAGIA
Authors: Keith Edward O. , Ortiz Charles L.
Published: August 2006

Abstract

Northern elephant seal (Mirounga angustirostris)pups undergo extended periods of terrestrial aphagia after weaning and exhibit a paradoxical fasting hyperglycemia. To investigate the details of glucose metabolism during this period, reversible and irreversible radiotracers were used to determine the body mass of glucose, and rates of glucose turnover, recycling, and oxidation in fasting seal pups. A typical 75 kg pup has a glucose mass of about 4.5 g (60 mg/kg), and a blood glucose concentration of about 174 mg/dl. Blood glucose removal rate was about 30 grams per day (17 mg/kg · h‐1), but less than 2.5% of this glucose was oxidized, contributing less than 1% of the total metabolic rate. About 20% of the glucose pool was removed from the blood per hour, yielding a turnover time in the vascular space of about five hours. Most glucose removed from the blood was returned to the blood by recycling. Such recycling may contribute to mechanisms which prolong survival during fasting, such as high rates of triacyclglycerol turnover, synthesis of new protein pools, low ketone levels, and the Cori cycle which is important during diving.
SEA OTTERS AND BENTHIC PREY COMMUNITIES IN WASHINGTON STATE
Authors: Kvitek Rikk G. , Shull David , Canestro Don , Bowlby Edward C. , Troutman Barry L.
Published: August 2006

Abstract

An August 1987 benthic survey of otter‐free and otter‐occupied areas along the outer coast of Washington State's Olympic Peninsula confirms that this area has been as profoundly influenced by sea otters as other rocky, nearshore communities studied in California, Canada, and Alaska. Prey density, size, and biomass were found to be negatively correlated with sea otter abundance, suggesting that the re‐introduction of sea otters to this area in 1969–1970 has profoundly affected invertebrate prey abundance and distribution, particularly that of the red sea urchin, Strongylocentrotus franciscanus. Red urchin distribution appears to influence algal groups differently and in a manner consistent with current otter/urchin/kelp theory. Foliose red algal abundance was negatively related to urchin numbers and coralline crusts were positively correlated. Aerial photographs of Macrocystis integrifolia cover at Cape Alava suggest an increase since the introduction of sea otters. Given the present distribution of prey along the Olympic Peninsula coast, we conclude that as the sea otter population continues to grow, range expansion is more likely to occur to the north, which may also lead to possible conflicts with an increasing sea urchin fishery and Native American set net activity.
FLIPPERS AND PINNIPED PHYLOGENY: HAS THE PROBLEM OF CONVERGENCE BEEN OVERRATED?
Authors: Wyss André R.
Published: August 2006

Abstract

The phylogenetic relationships of the major groups of pinnipeds are of longstanding controversy. According to prevailing paleontological opinion, pinnipeds comprise two distinct lineages of independent terrestrial carnivoran origin, A logical correlate of this view is that an enormous degree of convergence accounts for the striking resemblances of these groups.

It has been generally supposed that derived similarities common to pinnipeds are independently acquired adaptations to a highly constraining environment. This has not been adequately substantiated. Moreover, considerable evidence favors a contrary conclusion. Acceptance of convergence necessarily rests on demonstration that taxa possessing characters suspected to be convergent are in fact not mutal nearest allies. In the absence of such phylogenetic information, shared derived characters are indicative of common ancestry irrespective of whether they are deemed “functionally important.” Given meager support for the proposition that pinnipeds are related to different terrestrial lineages, it is currently more judicious to regard the group's origin as monophyletic. In addition to the presumed prevalence of convergence, biogeography, the high degree of morphological divergence of phocids, and the aberrant nature of phocines have improperly contributed to acceptance of independent pinniped origins.
TRENDS IN THE INSHORE RIGHT WHALE POPULATION OFF SOUTH AFRICA, 1969–1987
Authors: Best Peter B.
Published: August 2006

Abstract

Results of annual aerial surveys of the right whale population along the southern coast of South Africa from 1971 to 1987 are analysed. About 91.5% of cows with calves and 82% of unaccompanied adults on the South African coast in spring are found within the standard survey area, with some indications that the range is expanding up the west coast. In the nearshore region, most right whales (90%) are found within 1.85 km, and all cows with calves within 0.93 km, of the coast. Within the standard survey area, specific areas of concentration can be predictably identified, both for cows with calves and unaccompanied adults. Although total counts (and counts expressed per hour flown) have increased overall, by a best estimate of 6.8% (95% CL 4.6, 9.0) per year from 1971 to 1987, some concentration areas for both classes have failed to show an increase over the same time period. Photographic flights since 1979 have permitted the movements of individually identified adult females to be monitored between successive calves. In at least one concentration area for which no overall increase between 1971 and 1987 was apparent (Mossel Bay), a large net emigration rate was found, nearly all of which involved a shift to the main nursery area to the west, off De Hoop. Reasons for the dissimilar dynamics of different concentration areas are not yet known.
RATES AND POTENTIAL CAUSES OF MORTALITY IN NORTH ATLANTIC RIGHT WHALES (EUBALAENA GLACIALIS)
Authors: Kraus Scott D.
Published: August 2006

Abstract

North Atlantic right whale mortality rates range from 2% to 17% over the first four years of life. Sources of mortality in this population include ship collisions, entanglements, and natural causes. A combined analysis of stranding data, entanglement records, and photographic information indicates that approximately one third of all right whale mortality is caused by human activities. Anthropogenic sources of right whale mortality may be a significant factor inhibiting growth in the North Atlantic population.
OBTAINING SKIN SAMPLES FROM LIVING SPERM WHALES
Authors: Whitehead Hal , Gordon Jonathan , Mathews Elizabeth A. , Richard Kenny R.
Published: August 2006

Abstract

Samples of sperm whale skin, useful for modern molecular analyses of DNA, can be obtained from living animals either by collecting skin sloughed naturally by the whales, or by using biopsy darts fired from crossbows or compound bows. Sloughed skin was found frequently in warm waters, and particular samples could often be linked to photographs which enabled individuals to be identified. However, sloughed skin seemed less available at higher latitudes. Two types of darts were found to collect skin but collected samples were very small (<4 mm2) and insufficient for repeated DNA fingerprinting analyses. Sperm whales always reacted to darting by “startling” and showing changes of behavior over the next few minutes, but we found no indications of longer‐term effects. In warm water studies, collection of sloughed skin seems to be generally effective, but for samples of sperm whale tissue at high latitudes modifications could probably be made to either of the darts in order to obtain larger‐sized samples.
INFRARED SENSING OF THE UNDER‐SNOW LAIRS OF THE RINGED SEAL
Authors: Kingsley Michael C. S. , Hammill Michael O. , Kelly Brendan P.
Published: August 2006

Abstract

Airborne sensing of emitted infrared (IR) was tested as a means of detecting under‐snow lairs of the ringed seal (Phoca hispida) in study areas in Resolute Passage, N.W.T. Lairs and regularly used large breathing holes could in some cases be detected by emitted IR from altitudes of up to 180 m. Lairs were more easily detected if they had thin roofs, and detectability was higher before sunrise, and under conditions of low wind, low ambient temperature and high cloud cover.
REPRODUCTION, SURVIVAL AND TAG LOSS IN CALIFORNIA SEA OTTERS
Authors: Siniff Donald B. , Ralls Katherine
Published: August 2006

Abstract

We observed 40 California sea otters, Enhydra lutris, that were instrumented with implanted radio transmitters and flipper‐tagged, and obtained additional data on the reproduction of tagged female otters from the California Department of Fish and Game.

The proportion of instrumented females accompanied by a pup peaked in the spring, with a secondary peak in the fall. Two methods of estimating the annual reproductive rate gave comparable values of 0.90 and 0.94. The average inter‐birth interval was 389 d. Two methods of estimating pup survival to weaning gave values of 0.46 and 0.58. Pups either remained with a female less than 80 or more than 120 d. Early mortality of dependent pups appears to be more frequent in California than in Prince William Sound, Alaska.

Two methods of estimation indicated that adult females had the highest survival rates and adult males the lowest. Juvenile females had lower survival rates than adult females but juvenile males had higher survival rates than adult males. The survival rate of juvenile females was lower than that of juvenile males.

The estimated annual loss rate for flipper‐tags, based on the instrumented individuals, was 0.26. More individuals lost two tags than would be expected by chance. It is unlikely that accurate estimates of sea otter survival rates can be derived from observations of tagged individuals.
SEXUAL DIMORPHISM IN NEWBORN SOUTHERN SEA LIONS
Authors: Cappozzo H. Luis , Campagna Claudio , Monserrat Jose
Published: August 2006

Abstract

Male southern sea lion, Otaria byronia, pups born at Peninsula Valdés, Argentina, were significantly heavier (13.7 ± 1.6 kg, n = 37 vs 12.3 ± 1.4 kg, n= 38) and longer (0.82 ± 0.04 m, n= 29 vs. 0.79 ± 0.03 m, n= 29) than females. The rate of mass and length gain during the first month of life did not differ between the sexes (males: 0.21 kg/d, 0.003 m/d; females: 0.20 kg/d, 0.004 m/d). Sex differences in pup body size were not reflected in female nursing behavior, attendance patterns, and duration of feeding trips. These results suggest that southern sea lion mothers invest more energy in sons than in daughters during gestation, a difference consistent with the importance of large body size to the reproductive success of males in a polygynous species.
DIET OF WEDDELL SEALS LEPTONYCHOTES WEDDELLII AT VESTKAPP, EASTERN WEDDELL SEA (ANTARCTICA), IN RELATION TO LOCAL FOOD SUPPLY
Authors: Plötz Joachim , Ekau Werner , Reijnders Peter J. H.
Published: August 2006

Abstract

Thirteen Weddell seals (Leptonychotes weddellii) were collected at Vestkapp, eastern Weddell Sea coast, in austral spring 1986. All stomachs contained partially digested food. The mean wet weight of stomach contents was 7.5 kg, 3.3% of the. mean body weight of the collected seals. Twelve fish species and three cephalopod species were identified from 372 left otoliths and 25 lower beaks, representing 58.4% of 679 total prey items obtained. Composition by number of total prey was: Chionodraco myersi (15.8%), Trematomus eulepidotus (10.0%), Pagetopsis maculatus (9.7%), Racovitzia glacialis (9.6%) and Cryodraco antarcticus (4.1%). Otoliths of the seven other fish species and beaks of the three cephalopod species together represented 9.1% of total prey numbers. The pooled wet weights calculated from 13 prey species (regressions for two octopod species were not available) amounted to 43.5 kg food mass and represented 44.7% of the combined food mass in all stomachs. Composition by mass was: C. myersi (44.5%), T. eulepidotus (19.8%), squid Psychroteuthis glacialis (8.5%), P. maculates (7.9%), C. antarcticus (7.1%) and R. glacialis (6.2%). The remaining 7 fish species together represented 5.8% by mass. Temporal variation in food availability was apparent. Midwater fish Pleuragramma antarcticum was the staple food of Weddell seals from the same area during the 1985 summer, whereas it was absent in the samples taken in spring 1986. Estimates of fish biomass from net hauls demonstrate a highly variable availability of pelagic food resources for top predators in the Vestkapp area.
KILLER WHALES,ORCINUS ORCA, IN THE SOUTHEASTERN BERING SEA: RECENT SIGHTINGSandPREDATION ON OTHER MARINE MAMMALS
Authors: Frost Kathryn J. , Russell Richard B. , Lowry Lloyd F.
Published: August 2006

An unusual number of killer whales appeared in inshore waters of the southeastern Bering Sea in summer 1989 and 1990. Multiple sightings occurred in Bristol and Kuskokwim bays where killer whales had been seen only rarely in previous years. Three animals became stranded on mud flats in Kuskokwim Bay but were able to free themselves on a high tide. Killer whales were observed interacting with salmon, harbor seals, Steller sea lions, walruses, and beluga whales. Detailed observations were made of killer whales attacking belugas in the Naknek River. Local conditions and behavioral adaptations may reduce the susceptibility of belugas to killer whale predation. Continued killer whale activity in this area would be unlikely to affect fish resources, but might have some influence on beluga whales.