bluuebunny/crossref_metadata_2025 huggingface dataset:
Conservation goals and fisheries management units for Atlantic salmon in the Baltic Sea area
Authors: Koljonen M‐L.
Published: April 2005

The effective application of genetic information in fisheries management strategies implies political goal setting taking both conservation and fisheries management into account. The concept of sustainable use as set out by the Convention on Biological Diversity offers a valuable starting point in this respect, since the criterion for it is defined as the maintenance of genetic diversity within each species. However, strategic decisions are also needed on the practical level, where the actual genetic information can be taken into account. Genetic factors, such as glacial differentiation, the postglacial genetic structure of populations, gene flow levels and the probability of the existence of adaptive differences, have an effect on the formation of conservation and management units and on the long‐term strategy for the sustainable use of aspecies. The Atlantic salmon (Salmo salar) in the Baltic Sea area is treated here as an example of a complicated management problem with a highly hierarchical genetic structure associated with marked loss of naturally reproductive stocks, extensive hatchery production and an effective international offshore fishery. The implications of genetic factors for the conservation and management strategy of the Baltic salmon is discussed in the light of the goals set by the Convention on Biological Diversity, the Straddling Fish Stocks and Highly Migratory Fish Stocks Agreement, the Habitats Directive of the European Union and the International Baltic Sea Fishery Commission.
Coelacanths: a human responsibility
Authors: Fricke H.
Published: April 2005

The living coelacanth Latimeria chalumnae has a unique position in world biodiversity which raises important questions about conservation and ethics. Some relevant details of coelacanth biology are summarized, including those obtained by direct observation from submersibles. The importance of the coelacanth for evolutionary theory and palaeontology is shown to be paralleled in cultural, literary and artistic areas of human heritage. Threats to the Comoran coelacanths from artisanal fishing are described and conservation measures discussed in relation to local customs and economies as well as the promotion of tourism to spread a new awareness and concern for coelacanths worldwide.
Genetic diversity of coastal Northwest Atlantic herring populations: implications for management
Authors: McPherson A. A. , Stephenson R. L. , O'Reilly P. T. , Jones M. W. , Taggart C. T.
Published: April 2005

Analysis of nine tetranucleotide microsatellite loci for Atlantic herring at five locations in the Northwest Atlantic including the Bras d'Or Lakes shows considerable genetic variation and significant population structure within the Coastal Nova Scotia management component, and among coastal populations and herring collected from Georges Bank. However, results are also consistent with gene flow across the Gulf of Maine. The magnitude of differentiation between the Bras d'Or Lakes sample and all others considered was sufficient to warrant further investigation. These data support the precautionary spawning‐ground based management approach implemented in this area.
Rearing conditions influence refuge use among over‐wintering Atlantic salmon juveniles
Authors: Griffiths S. W. , Armstrong J. D.
Published: April 2005

At low population densities, both hatchery‐ and wild‐reared Atlantic salmon Salmo salar, which were progeny of a common genetic stock, occupied sub‐gravel shelters alone. However, at high population densities, hatchery‐reared fish occurred within shelters in significantly higher numbers than wild‐reared fish. There was a significant effect of time after introduction to the experimental arenas on the proportion of hatchery‐reared fish sheltering. These results show that rearing environment influences the behaviour of Atlantic salmon parr during winter and may also affect the carrying capacity of their environment.
Effect of dietary ascorbic acid supplementation and chronic hypoxia on sea bream growth and vitamin C status
Authors: Henrique M. M. F. , Gouillou‐Coustans M. F. , Gomes E.
Published: April 2005

Hypoxia (55% DO) and ascorbic acid (AA) supplementation level (0, 10, 25 and 50 mg AA equivalent kg—1 diet, supplied as ascorbyl polyphosphate) did not significantly alter juvenile sea bream Sparus aurata growth, body composition, survival and skin hydroxyproline concentration. Liver, head kidney and spleen AA concentrations significantly decreased with decreasing dietary AA level, but were not influenced by hypoxia. This study showed that sea bream AA requirements were not influenced by chronic hypoxic stress.
Growth patterns of Arctic charr in five high altitude lakes in a French Alpine massif
Authors: Cavalli L. , Pech N. , Tron L. , Chappaz R.
Published: April 2005

The growth of Arctic charr Sahelinus alpinus in five high altitude lakes differed between lakes during the first 2 years but was similar thereafter. The average temperature during the summer had a direct effect on growth and an indirect effect on the productivity level of the lakes, particularly on the abundance of planktonic crustaceans. The results highlight the importance of planktonic crustacea in the growth of Arctic charr.
The ontogeny of courtship, colour and sperm production in male guppies
Authors: Evans J. P. , Pitcher T. E. , Magurran A. E.
Published: April 2005

The onset of sexual behaviour in three age classes of male guppy Poecilia reticulata occurred in synchrony with the appearance of body colouration and anal fin differentiation but not with sperm production. There was also a positive correlation between sperm production and sexual behaviour in the two older age classes.
Attraction of slimy sculpins to chemical cues of brook charr eggs
Authors: Mirza R. S. , Chiers P.
Published: April 2005

In a laboratory study to examine the responses of slimy sculpin Cottus cognatus to chemical cues of brook charr Salvelinus fontinalis eggs, water that held freshly laid eggs (<20 min old), water‐hardened eggs (i.e. eggs >4 h old) or injured eggs was collected and used in a series of two‐choice tests. Slimy sculpin were exposed to paired stimuli of (1) hard egg water v. control water, (2) fresh egg water v. control water, (3) hard egg water v. injured egg water or (4) hard egg water v. fresh egg water. Sculpin spent considerably more time on the side of the tank with hard egg water and fresh egg water v. control water and injured egg water v. hard egg water. Sculpin did not show a preference for hard egg water v. fresh egg water. In a field study, brook charr were attracted to chemical cues from brook charr eggs, suggesting that brook charr eggs produce sufficient odour to attract some species under natural conditions.
Sediment preferences and size‐specific distribution of young‐of‐the‐year Pacific halibut in an Alaska nursery
Authors: Stoner A. W. , Abookire A. A.
Published: April 2005

A combination of laboratory experiments and field surveys was used to test the hypotheses that responses to sediments change with fish size and that sediment grain‐size is the predominant environmental factor affecting small‐scale distribution in young‐of‐the‐year (yoy) Pacific halibut Hippoglossus stenolepis. Laboratory tests showed that the smallest fish (31–40 mm LT) chose fine sediments (muddy and fine sands), fish 51–70 mm had high selectivity (primarily medium sand), and the largest fish (80–150 mm) were not selective although they avoided the largest grain‐sizes (pebbles and granules). Sediment preferences were correlated with size‐dependent burial capabilities. Beam trawl collections were made over a 6 year period in Kachemak Bay, Alaska, to examine the distribution of yoy Pacific halibut (14–120 mm LT) using small size classes (e.g. 10 mm intervals). Canonical correlation analysis showed that the per cent of sand in the sediment was a highly significant variable for all but one size and date combination. Catch per unit of effort (CPUE) for newly settled fish (<30 mm LT) was highest on very fine sand, fish 41–80 mm were most abundant on fine sand, and the largest yoy fish (81–120 mm) were abundant over a range of sediments from fine sand to mud. Except for the smallest fish, Pacific halibut in the field were associated with sediments somewhat finer than predicted from the laboratory experiments; however, virtually all were captured where they could bury easily. The ability of flatfish to bury and shelter in sediment is related to fish size; consequently, habitat associations shift rapidly during the first year of life. Habitat models for yoy flatfishes should consider size‐dependent shifts in capabilities and preferences.
Ontogenetic variations of thermal optimum for growth, and its implication on thermolabile sex determination in blue tilapia
Authors: Baras E. , Mpo'n'tcha A. , Driouch H. , Prignon Ch. , Mélard C.
Published: April 2005

Knowledge of how the optimum temperature for growth (T°opt) varies during ontogeny, and how close it is to the temperatures that induce phenotypic masculinization is fundamental to the understanding of the evolution of thermolabile sex determinism (TSD) in fishes. In blue tilapia Oreochromis aureus, T°opt is 32·6° C at the start of exogenous feeding (10mg fish) and it decreases by c. 1° C each time that the fish body mass increases by an order of magnitude. Temperatures <35° C are not sufficient to induce complete phenotypic masculinization. Based on a multiple‐regression model (r2=0·938) plotting growth against body mass and water temperature, genotypically female tilapia living at high temperatures during the thermosensitive period (21–28 days) and being reversed into phenotypic males would incur an initial growth disadvantage over fish living at T°opt, but not over those living at slightly colder temperatures (27–29° C). This initial disadvantage would be later compensated for by faster growth because of between‐sex growth dimorphism to the detriment of phenotypic females. These arguments suggest that there is no definite pressure against the selection of TSD in blue tilapia and probably other Oreochromis spp.
Plasma steroid concentrations in relation to the reproductive cycle of cultured male Rhamdia quelen
Authors: Barcellos L. J. G. , Wassermann G. F. , Scott A. P. , Woehl V. M. , Quevedo R. M. , Ittzés I. , Krieger M. H. , Lulhier F.
Published: April 2005

The plasma concentrations of testosterone (T) of cultured jundiáRhamdia quelen increased progressively during spermatogenesis and reached a peak at the beginning of spermiation (e.g. fluidization of the sperm and production of milt). Plasma peaks of T occurred simultaneously to the highest production of T by the testis, however, both plasma concentrations and testis production of T decreased progressively during spermiation. Concentrations of 11‐ketotestosterone (11‐KT) peaked c. 1 month after the peak of T, concomitant with enhanced production of 11‐KT by the testis. The concentrations of 11‐KT during the first cycle were extremely high (> 1 μg ml−1), but less during the second and third cycles, suggesting that this steroid is most important during the pubertal phase in male jundiá. Plasma concentrations of both 17‐hydroxy‐4‐pregene‐3,20‐dione (17‐P) and 17,20β‐dihydroxy‐4‐pregen‐3‐one (17,20β‐P) were significantly higher during spermiation than at any other times, and showed little variation. The pattern of steroid changes was cyclical and consistent with their proposed roles in male fish reproduction.
Development of epidermal and mucosal galectin containing cells in metamorphosing leptocephali of Japanese conger
Authors: Nakamura O. , Saeki M. , Kamiya H. , Muramoto K. , Watanabe T.
Published: April 2005

The epidermis of premetamorphic leptocephali of Japanese conger Conger myriaster consisted of only a few cell layers including congerin‐ (a galectin) containing club cells. The epidermis increased in thickness after metamorphosis, mainly due to a preponderant development of club cells. This suggested that the biological significance of congerins increased at this stage, which may be related to a change in life style. Epidermal mucous cells showed only limited distribution. Immuno‐positive cells in the mucosal epithelia of the buccal cavity wall and oesophagus were not found in the youngest individuals. Though these cells were observed at the commencement of metamorphosis, the development of the epithelia and club cells was apparently retarded compared to that of the epidermis. No immuno‐staining was found in the gills at any stages.
The stock structure and migrations of plaice populations on the west coast of England and Wales
Authors: Dunn M. R. , Pawson M. G.
Published: April 2005

Plaice Pleuronectes platessa populations on the west coast of England and Wales are currently managed as two stocks: in ICES Division VIIa (Irish Sea, Cardigan Bay and St George's Channel), and ICES Divisions VIIf&g (Bristol Channel and Celtic Sea). A total of 13,784 plaice were fitted with Petersen tags and released in these areas during 1979–1980 and 1993–1996. Analysis of the 2788 recaptures received by June 2000 confirmed known spawning and feeding grounds in the region. It showed also that plaice >25 cm LT tended to undertake extensive spatial movements. At this size, female plaice were likely to be mature or maturing for the first time, whilst males were probably mature. Tag recaptures indicated resident sub‐stocks of plaice in the north‐east Irish Sea, the south‐east Irish Sea, Cardigan Bay and Bristol Channel, a contingent of plaice in all areas that undertook permanent dispersal to other areas, and a contingent which originated in the south‐east Irish Sea and migrated to spawn in the Bristol Channel. Plaice originating in the Bristol Channel rarely moved north into ICES Vila. A general hypothesis of plaice population structure in the region is presented and discussed in relation to stock assessment.
Changes in plasma levels of gonadal steroids and putative gonadotropin in association with spawning and brooding behaviour of male demoiselles
Authors: Pankhurst N. W. , Peter R. E.
Published: April 2005

Nesting male demoiselles Chromis dispilus were captured and blood sampled under water by divers, and plasma levels of reproductive hormones correlated with behavioural status at the time of capture. Plasma gonadotropin‐II (dGtH‐II) was measured using a heterologous assay based on carp GtH‐II standards and an antibody to the β‐subunit of cGtH‐II. Plasma samples diluted parallel to standards in the assay, and there was a significant transient increase in dGtH‐II in response to treatment with gonadotropin releasing hormone analogue (GnRHa). Male demoiselles had elevated plasma levels of dGtH‐II during periods of reproductive display, but low levels of dGtH‐II during periods of brooding, irrespective of egg stage. Plasma testosterone levels followed a similar pattern whereas plasma 11‐ketotestosterone and 17,20β‐dihydroxy‐4‐pregnen‐3‐one levels tended to remain elevated during the early phases of egg brooding. The results are consistent with earlier studies showing that reproductive hormone levels in demoiselles are behaviourally mediated, and support the view that behavioural alterations of reproductive endocrine status in fishes are mediated through the action of GnRH.
Relationships between Na+, K+‐ATPase, sialic acid content and fluidity in rainbow trout density‐separated erythrocytes
Authors: Salvolini E. , Nanetti L. , Moretti N. , Vignini A. , Martarelli D. , Frontini A. , Santroni A. M. , Falcioni G. , Mazzanti L.
Published: April 2005

A correlation was found between membrane fluidity, sialic acid (SA) content and Na+, K+‐ATPase activity in the rainbow trout Oncorhynchus mykiss erythrocyte membrane and this suggests that alterations in erythrocyte Na+, K+‐ATPase activity might be caused by modified membrane fluidity through modified SA content.
Home management of childhood febrile illnesses in a rural community in Nigeria
Authors: Olaogun Adenike A.E. , Ayandiran Olufemi , Olasode Olayinka A. , Adebayo Abayomi , Omokhodion Folasade
Published: April 2005

Objective:  To assess the care given to febrile children under 5 years old at home prior to attending health facility.

Design:  Cross sectional design.

Setting:  Outpatient clinic of a government health facility.

Subjects:  Two hundred mothers who brought their sick children to the outpatient department were interviewed.

Results:  The ages of mothers ranged from 15 to 50 years (mean of 26.2 years). Most of them had formal education although below grade 12. Only 12.5% of them were full‐time housewives. Others were engaged in self‐employed occupations. Fifty‐one percent of the children were females. Their ages ranged between 6 months and 5 years with a mean of 2.6 years. Over 60% of the children were suffering from symptoms of acute respiratory infections while 28% had symptoms of malaria. There was no significant difference between mothers’ diagnosis and researchers’ diagnosis (χ

2
 = 0.199, P < 0.05). The duration of children's illnesses spanned from 1 to 60 days (mean of 4.8 days). Only one mother reported at the clinic within 24 h of the onset of the child's illness. Eighty‐one percent had taken action before coming to clinic. They had used combinations of drugs namely antipyretics, antimalarials and antibiotics. The average amount spent on drugs was US$0.57. These drugs were purchased at local medicine stores.

Conclusion:  The findings indicate home use of drugs that were not prescribed by health professionals. There is therefore a strong need to give appropriate education and counselling to mothers/care givers and medicine vendors on early detection and proper home management of febrile illnesses.
South African Red Cross Flying Doctors Service quality and safety in the rural and remote South African environment
Authors: Exadaktylos Aristomenis K. , Haffejee Farhaad , Wood Darryl , Erasmus Philip
Published: April 2005

Context:  The South African Red Cross Air Mercy Service and its Flying Doctors Service provides health care to far flung and disadvantaged communities in South Africa.

Purpose:  The purpose of this article is to highlight the importance and effectiveness of the service in providing health care to a range of people who have poor or no access to certain health services in South Africa.

Methods:  Data and information was collected from records and statistical data of our service. Data was evaluated and compiled into a report highlighting the achievements of this organisation from its infancy to the present day.

Findings:  The Flying Doctor and Health Outreach Programme has made a difference in improving health care by providing specialist services, transport of patients and training of medical personnel in outlying areas of South Africa that have poor access to health care. Emergency Air Ambulance and Rescue Services have proven to be supportive in providing rapid advanced life support and rescue services to patients in emergency situations. Many lives have been saved through this service.

Conclusion:  The South African Red Cross Air Mercy Service plays a crucial role in delivering specialised health care to disadvantaged communities in South Africa.
NARRATIVE ARTIFICE AND WOMEN'S AGENCY
Authors: KALBIAN ALINE H.
Published: April 2005

The choice to pursue fertility treatments is a complex one. In this paper I explore the issues of choice, agency, and gender as they relate to assisted reproductive technologies (ARTs). I argue that narrative approaches to bioethics such as those by Arthur Frank and Hilde Lindemann Nelson clarify judgments about autonomy and fertility medicine. More specifically, I propose two broad narrative categories that help capture the experience of encounters with fertility medicine: narratives of hope and narratives of resistance. This narrative typology captures the inevitable conflict that women feel when they become subjects of fertility medicine. On the one hand, they must remain hopeful; on the other, they must not surrender themselves completely. Nelson's account of counterstories as narratives of resistance helps us see how women can reconcile the experience of a strong desire to have children with the desire to remain authentic and whole.
DOES A NORMAL FOETUS REALLY HAVE A FUTURE OF VALUE? A REPLY TO MARQUIS
Authors: LOVERING ROBERT P.
Published: April 2005

The traditional approach to the abortion debate revolves around numerous issues, such as whether the foetus is a person, whether the foetus has rights, and more. Don Marquis suggests that this traditional approach leads to a standoff and that the abortion debate ‘requires a different strategy.’1 Hence his ‘future of value’ strategy, which is summarized as follows:

A normal foetus has a future of value.

Depriving a normal foetus of a future of value imposes a misfortune on it.

Imposing a misfortune on a normal foetus is prima facie wrong.

Therefore, depriving a normal foetus of a future of value is prima facie wrong.

Killing a normal foetus deprives it of a future of value.

Therefore, killing a normal foetus is prima facie wrong.

In this paper, I argue that Marquis's strategy is not different since it involves the concept of person – a concept deeply rooted in the traditional approach. Specifically, I argue that futures are valuable insofar as they are not only dominated by goods of consciousness, but are experienced by psychologically continuous persons. Moreover, I argue that his strategy is not sound since premise (1) is false. Specifically, I argue that a normal foetus, at least during the first trimester, is not a person. Thus, during that stage of development it is not capable of experiencing its future as a psychologically continuous person and, hence, it does not have a future of value.
The impact of news, oil prices, and global market developments on Russian financial markets1
Authors: Hayo Bernd , Kutan Ali M.
Published: April 2005

This paper analyses the impact of news, oil prices, and international financial market developments on daily returns on Russian bond and stock markets. First, regarding returns, energy news affects returns, while news from the war in Chechnya is not significant. Market volatility does not appear to be sensitive to either type of news. Second, a significant effect of the growth in oil prices on Russian stock returns is detected. Third, the international influence on Russian financial markets depends upon the degree of financial liberalization. The higher the degree of financial liberalization, the stronger is the impact of US stock returns on Russian financial markets. In addition, banking reform and interest rate liberalization efforts seem to dictate the globalization of Russian stock markets, while it is the progress in liberalizing securities markets and non‐bank financial institutions that matters more for the globalization of Russian bond markets.
Economic transition, gender bias, and the distribution of earnings in China*
Authors: Bishop John A. , Luo Feijun , Wang Fang
Published: April 2005

Market‐oriented economic reform, which accelerated after 1992, has brought substantial changes to the Chinese economy. This dramatic economic transition was raised two important questions: ‘How are women faring in the transition from a planned economy to a market economy?’ and ‘Are some women faring relatively better than other women’? We use data from the Chinese Household Income Projects for the years 1988 and 1995, a standard earnings equation, and quantile regressions to estimate and decompose the earnings gap. Our findings suggest that while the earnings gap has increased, the fraction of the gap ‘unexplained’ by differences in human capital variables such as education and experience has declined over time. This result is particularly pronounced for low earning women.
Association between novel indices of malnutrition–inflammation complex syndrome and cardiovascular disease in hemodialysis patients
Authors: Terrier Nathalie , Senécal Lynne , Dupuy Anne‐Marie , Jaussent Isabelle , Delcourt Cécile , Leray Hélène , Rafaelsen Silje , Bosc Jean‐Yves , Maurice François , Canaud Bernard , Cristol Jean‐Paul
Published: April 2005

Background:  Inflammation and malnutrition are recognized as important risk factors for cardiovascular disease (CVD) in hemodialysis (HD) patients. Owing to substantial short‐term variability of serum C‐reactive protein (CRP), more reliable markers of malnutrition–inflammation complex syndrome should be sought with stronger associations with the risk of CVD in HD patients. We therefore explored the clinical relevance of a composite inflammatory index (prognostic inflammatory and nutritional index [PINI]) and of muscle protein mass indicators, derived from creatinine kinetics.

Methods:  This cross‐sectional study included 177 HD patients (89 women and 88 men; median age, 67.73 years). CVD and risk factors were assessed using medical charts, clinical examination, and biochemical measurements performed at inclusion. Lean body mass (LBM) was derived from creatinine kinetic modeling, whereas PINI was calculated as the ratio (CRP ×α1‐acid‐glycoprotein)/(albumin × transthyretin). Patients were divided according to the presence or absence of established CVD.

Results:  The traditional risk factors diabetes (odds ratio [OR], 5.83; p = 0.0045) and smoking (OR, 3.50; p < 0.02) were associated with an increase in prevalent CVD. Low transthyretin (OR, 3.79; p < 0.02) and high levels of CRP (OR, 2.70; p < 0.05), PINI (OR, 3.44; p < 0.02), observed LBM (OR, 3.01; p < 0.05), and the ratio of observed/expected LBM (OR, 4.24; p < 0.01) were associated with CVD after adjustment for age, sex, dialysis center, and dialysis vintage. After additional adjustment for diabetes and smoking, only PINI (OR, 2.85; p = 0.0446) and observed/expected LBM (OR, 2.96; p = 0.0361) were still significant.

Conclusion:  PINI and LBM are associated with increased relative risk for having CVD and could be used routinely to examine the degree of severity of malnutrition inflammation complex syndrome.
The clinical syndrome of Alzheimer's disease: aspects particularly relevant to clinical trials
Authors: Mohs R. C.
Published: April 2005

This paper describes the natural history of the clinical syndrome of Alzheimer's disease (AD) including the cognitive deficit, the neuropsychiatric symptoms, impact on daily functioning, risk factors, medical complications and impact on the use of health‐care resources. The clinical presentation of the disease varies greatly from the prodrome through end stage; instruments used to quantify the severity of each aspect of the disease have been developed and are described along with their use in clinical drug trials. Drug treatments for AD are usually developed by first showing a positive effect on the cognitive deficit, with later studies investigating drug effects on other clinical aspects of the disease.
OPTIMIZATION OF HYDROLYSIS CONDITIONS FOR THE PRODUCTION OF THREADFIN BREAM (NEMIPTERUS JAPONICUS) HYDROLYSATE BY ALCALASE
Authors: NORMAH I. , JAMILAH B. , SAARI N. , YAAKOB B. CHE MAN
Published: April 2005

The hydrolysis of Threadfin bream (Nemipterus japonicus) by Alcalase was optimum at 60C, pH 8.5, 120 min using an enzyme substrate (ES) ratio of 2%. With these hydrolysis conditions, 20% hydrolysis was achieved and 70% nitrogen was recovered. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis revealed more degradation with 1, 3 and 4% ES. Two percent ES produced mixtures of protein bands with a wider range of molecular weights, thus it was chosen as the optimum hydrolysis ES ratio.
Inhibitory and excitatory intracortical circuits across the human sleep–wake cycle using paired‐pulse transcranial magnetic stimulation
Authors: Salih F. , Khatami R. , Steinheimer S. , Hummel O. , Kühn A. , Grosse P.
Published: April 2005

Studies using single‐pulse transcranial magnetic stimulation (TMS) have shown that excitability of the corticospinal system is systematically reduced in natural human sleep as compared to wakefulness with significant differences between sleep stages. However, the underlying excitatory and inhibitory interactions on the corticospinal system across the sleep–wake cycle are poorly understood. Here, we specifically asked whether in the motor cortex short intracortical inhibition (SICI) and facilitation (ICF) can be elicited at all in sleep using the paired‐pulse TMS protocol, and if so, how SICI and ICF vary across sleep stages. We studied 28 healthy subjects at interstimulus intervals of 3 ms (SICI) and 10 ms (ICF), respectively. Magnetic stimulation was performed over the hand area of the motor cortex using a focal coil and evoked motor potentials were recorded from the contralateral first dorsal interosseus muscle (1DI). Relevant data was obtained from 13 subjects (NREM 2: n= 7; NREM 3/4: n= 7; REM: n= 7). Results show that both SICI and ICF were present in NREM sleep. SICI was significantly enhanced in NREM 3/4 as compared to wakefulness and all other sleep stages whereas in NREM 2 neither SICI nor ICF differed from wakefulness. In REM sleep SICI was in the same range as in wakefulness, but ICF was entirely absent. These results in humans support the hypothesis derived from animal experiments which suggests that intracortical inhibitory mechanisms are involved in the control of neocortical pyramidal cells in NREM and REM sleep, but along different intraneuronal circuits. Further, our findings suggest that cortical mechanisms may additionally contribute to the inhibition of spinal motoneurones in REM sleep.
Computational modelling of H+‐coupled peptide transport via human PEPT1
Authors: Irie Megumi , Terada Tomohiro , Katsura Toshiya , Matsuoka Satoshi , Inui Ken‐ichi
Published: April 2005

H+‐coupled peptide transporter 1 (PEPT1) mediates the transport of small peptides and peptide‐like drugs in a pH‐ and voltage‐dependent manner. Here, we investigated the transport mechanisms of PEPT1 for neutral and charged substrates by experimental studies and computational simulation. Uptake studies revealed that the Michaelis‐Menten constant (Km) of glycylsarcosine (Gly‐Sar), a neutral substrate, decreased with a fall in pH from 7.4 to 5.5, but at pH 5.0, the Km increased again. In contrast, the Km value of an anionic substrate, ceftibuten, declined steadily with decreasing pH. Based on these findings and information from the literature, we hypothesized the transport mechanisms in which (1) H+ binds to not only the H+‐binding site, but also the substrate‐binding site; and (2) H+ at the substrate‐binding site inhibits the interaction of neutral and cationic substrates, but is necessary for that of anionic substrates. To validate these hypotheses, a computational model was constructed and various properties of substrate transport by PEPT1 were simulated. Our model reproduced the voltage dependence, hyperbolic saturation and bell‐shaped pH‐profile of Gly‐Sar transport. Moreover, the various transport properties of negatively and positively charged substrates were also reconstructed. These findings indicated that the inferred mechanisms are able to sufficiently interpret the transport of both neutral and charged substrates by PEPT1.
Insulin‐stimulated plasma membrane association and activation of Akt2, aPKC ζ and aPKC λ in high fat fed rodent skeletal muscle
Authors: Herr Henry J. , Bernard Jeffrey R. , Reeder Donald W. , Rivas Donato A. , Limon Jose J. , Yaspelkis Ben B.
Published: April 2005

Several recent reports using cell lines have suggested that both Akt and atypical protein kinase C (aPKC) ζ/λ are translocated to the plasma membrane (PM) in response to insulin. However, it has yet to be determined in skeletal muscle whether: (1) insulin increases PM‐associated Akt2, aPKC ζ and/or λ protein concentration, (2) the activity of these kinases is altered by insulin at the PM, and (3) high fat feeding alters the insulin‐stimulated PM concentration and/or activity of Akt2 and aPKC ζ/λ. Sprague‐Dawley rats were randomly assigned to either normal (n= 16) or high fat (n= 16) dietary groups. Following a 12 week dietary period, animals were subjected to hind limb perfusions in the presence (n= 8 per group) or absence (n= 8 per group) of insulin. In normal skeletal muscle, total PI3‐kinase, Akt2 and aPKC ζ/λ activities were increased by insulin. PM‐associated aPKC ζ and λ, and aPKC ζ/λ activity, but not Akt2 or Akt2 activity, were increased by insulin in normal muscle. High fat feeding did not alter total skeletal muscle Akt2, aPKC ζ or aPKC λ protein concentration. Insulin‐stimulated total PI3‐kinase, Akt2 and aPKC ζ/λ activities were reduced in the high fat fed animals. Insulin‐stimulated PM aPKC ζ, aPKC λ, aPKC ζ/λ activity and GLUT4 protein concentration were also reduced in high fat fed animals. These findings suggest that in skeletal muscle, insulin stimulates translocation of aPKC ζ and λ, but not Akt2, to the PM. In addition, high fat feeding impairs insulin‐stimulated activation of total aPKC ζ/λ and Akt2, as well as PM association and activation of aPKC ζ and λ.
An Octane-Fueled Solid Oxide Fuel Cell
Authors: Zhan Zhongliang , Barnett Scott A.
Published: April 2005

There are substantial barriers to the introduction of hydrogen fuel cells for transportation, including the high cost of fuel-cell systems, the current lack of a hydrogen infrastructure, and the relatively low fuel efficiency when using hydrogen produced from hydrocarbons. Here, we describe a solid oxide fuel cell that combines a catalyst layer with a conventional anode, allowing internal reforming of
iso
-octane without coking and yielding stable power densities of 0.3 to 0.6 watts per square centimeter. This approach is potentially the basis of a simple low-cost system that can provide substantially higher fuel efficiency by using excess fuel-cell heat for the endothermic reforming reaction.
Regulation of NAD Synthesis by the Trifunctional NadR Protein of
Salmonella enterica
Authors: Grose Julianne H. , Bergthorsson Ulfar , Roth John R.
Published: April 2005

The three activities of NadR were demonstrated in purified protein and assigned to separate domains by missense mutations. The N-terminal domain represses transcription of genes for NAD synthesis and salvage. The C-terminal domain has nicotinamide ribose kinase (NmR-K; EC 2.7.1.22) activity, which is essential for assimilation of NmR, converting it internally to nicotinamide mononucleotide (NMN). The central domain has a weak adenylyltransferase (NMN-AT; EC 2.7.7.1) activity that converts NMN directly to NAD but is physiologically irrelevant. This central domain mediates regulatory effects of NAD on all NadR activities. In the absence of effectors, pure NadR protein binds operator DNA (the default state) and is released by ATP (expected to be present in vivo). NAD allows NadR to bind DNA in the presence of ATP and causes repression in vivo. A superrepressor mutation alters an ATP-binding residue in the central (NMN-AT) domain. This eliminates NMN-AT activity and places the enzyme in its default (DNA binding) state. The mutant protein shows full NmR kinase activity that is 10-fold more sensitive to NAD inhibition than the wild type. It is proposed that NAD and the superrepressor mutation exert their effects by preventing ATP from binding to the central domain.
Cross-Resistance of
Escherichia coli
RNA Polymerases Conferring Rifampin Resistance to Different Antibiotics
Authors: Xu Ming , Zhou Yan Ning , Goldstein Beth P. , Jin Ding Jun
Published: April 2005

In this study we further defined the rifampin-binding sites in
Escherichia coli
RNA polymerase (RNAP) and determined the relationship between rifampin-binding sites and the binding sites of other antibiotics, including two rifamycin derivatives, rifabutin and rifapentine, and streptolydigin and sorangicin A, which are unrelated to rifampin, using a purified in vitro system. We found that there is almost a complete correlation between resistance to rifampin (Rif
r
) and reduced rifampin binding to 12 RNAPs purified from different
rpoB
Rif
r
mutants and a complete cross-resistance among the different rifamycin derivatives. Most Rif
r
RNAPs were sensitive to streptolydigin, although some exhibited weak resistance to this antibiotic. However, 5 out of the 12 Rif
r
RNAPs were partially resistant to sorangicin A, and one was completely cross-resistant to sorangicin A, indicating that the binding site(s) for these two antibiotics overlaps. Both rifampin and sorangicin A inhibited the transition step between transcription initiation and elongation; however, longer abortive initiation products were produced in the presence of the latter, indicating that the binding site for sorangicin A is within the rifampin-binding site. Competition experiments of different antibiotics with
3
H-labeled rifampin for binding to wild-type RNAP further confirmed that the binding sites for rifampin, rifabutin, rifapentine, and sorangicin A are shared, whereas the binding sites for rifampin and streptolydigin are distinct. Because Rif
r
mutations are highly conserved in eubacteria, our results indicate that this set of Rif
r
mutant RNAPs can be used to screen for new antibiotics that will inhibit the growth of Rif
r
pathogenic bacteria.
Heat Shock Protein 90 and Heat Shock Protein 70 Are Components of Dengue Virus Receptor Complex in Human Cells
Authors: Reyes-del Valle Jorge , Chávez-Salinas Salvador , Medina Fernando , del Angel Rosa M.
Published: March 2005

Dengue virus requires the presence of an unidentified cellular receptor on the surface of the host cell. By using a recently published affinity chromatography approach, an 84-kDa molecule, identified as heat shock protein 90 (HSP90) by matrix-assisted laser desorption ionization-time of flight mass spectrometry, was isolated from neuroblastoma and U937 cells. Based on the ability of HSP90 (84 kDa) to interact with HSP70 (74 kDa) on the surface of monocytes during lipopolysaccharide (LPS) signaling and evidence that LPS inhibits dengue virus infection, the presence of HSP70 was demonstrated in affinity chromatography eluates and by pull-down experiments. Infection inhibition assays support the conclusion that HSP90 and HSP70 participate in dengue virus entry as a receptor complex in human cell lines as well as in monocytes/macrophages. Additionally, our results indicate that both HSPs are associated with membrane microdomains (lipid rafts) in response to dengue virus infection. Moreover, methyl-β-cyclodextrin, a raft-disrupting drug, inhibits dengue virus infection, supporting the idea that cholesterol-rich membrane fractions are important in dengue virus entry.
Characterization of Homologous and Heterologous Rotavirus-Specific T-Cell Responses in Infant and Adult Mice
Authors: Jaimes María C. , Feng Ningguo , Greenberg Harry B.
Published: March 2005

During primary rotavirus (RV) infection, CD8
+
T cells play an important role in viral clearance as well as providing partial protection against reinfection. CD4
+
T cells are essential for maximal development of RV-specific intestinal immunoglobulin A. In this study, we took advantage of the cytokine flow cytometry technique to obtain a detailed map of H-2
b
- and H-2
d
-restricted CD8
+
and CD4
+
T-cell epitopes from the RV proteins VP6 and VP7. Three new CD8
+
T-cell epitopes (H-2
d
and H-2
b
restricted) and one new CD4
+
T-cell epitope (H-2
d
and H-2
b
restricted) were identified. Using these newly identified targets, we characterized the development and specificity of cellular immune responses in C57BL/6 and BALB/c mice during acute infection of infants and adults. We found that both the CD4
+
and CD8
+
responses peaked on days 5 to 7 after infection and then declined rapidly. Interestingly, both the response kinetics and tissue distributions were different when epitopes on VP6 and VP7 were compared. VP6 elicited a response which predominated in the intestine, while the response to VP7 was more systemic. Additionally, the T-cell responses elicited after homologous versus heterologous infection differed substantially. We found that during homologous infection, there was a greater response toward VP6 than that toward VP7, especially in the intestine, while after heterologous infection, this was not the case. Finally, in suckling mice, we found two peaks in the CD8 response on days 7 and 14 postinfection, which differed from the single peak found in adults and likely mimics the biphasic pattern of rotavirus shedding in infant mice.
Vaccine-Elicited Memory Cytotoxic T Lymphocytes Contribute toMamu-A*01-Associated Control of Simian/Human Immunodeficiency Virus 89.6P Replication in Rhesus Monkeys
Authors: Seaman Michael S. , Santra Sampa , Newberg Michael H. , Philippon Valerie , Manson Kelledy , Xu Ling , Gelman Rebecca S. , Panicali Dennis , Mascola John R. , Nabel Gary J. , Letvin Norman L.
Published: March 2005

The expression of particular major histocompatibility complex (MHC) class I alleles can influence the rate of disease progression following lentiviral infections. This effect is a presumed consequence of potent cytotoxic T-lymphocyte (CTL) responses that are restricted by these MHC class I molecules. The present studies have examined the impact of the MHC class I alleleMamu-A*01on simian/human immunodeficiency virus 89.6P (SHIV-89.6P) infection in unvaccinated and vaccinated rhesus monkeys by exploring the contribution of dominant-epitope specific CTL in this setting. Expression ofMamu-A*01in immunologically naive monkeys was not associated with improved control of viral replication, CD4+T-lymphocyte loss, or survival. In contrast,Mamu-A*01+monkeys that had received heterologous prime/boost immunizations prior to challenge maintained higher CD4+T-lymphocyte levels and better control of SHIV-89.6P replication thanMamu-A*01−monkeys. This protection was associated with the evolution of high-frequency anamnestic CTL responses specific for a dominant Mamu-A*01-restricted Gag epitope following infection. These data indicate that specific MHC class I alleles can confer protection in the setting of a pathogenic SHIV infection by their ability to elicit memory CTL following vaccination.
Characterization of DC-SIGN/R Interaction with Human Immunodeficiency Virus Type 1 gp120 and ICAM Molecules Favors the Receptor's Role as an Antigen-Capturing Rather than an Adhesion Receptor
Authors: Snyder Greg A. , Ford Jennifer , Torabi-Parizi Parizad , Arthos James A. , Schuck Peter , Colonna Marco , Sun Peter D.
Published: March 2005

The dendritic cell (DC)-specific intercellular adhesion molecule 3 (ICAM-3)-grabbing nonintegrin binding receptor (DC-SIGN) was shown to bind human immunodeficiency virus type 1 (HIV-1) viral envelope protein gp120 and proposed to function as a Trojan horse to enhancetrans-virus infection to host T cells. To better understand the mechanism by which DC-SIGN and DC-SIGNR selectively bind HIV-1 gp120, we constructed a series of deletion mutations in the repeat regions of both receptors. Different truncated receptors exist in different oligomeric forms. The carbohydrate binding domain without any repeats was monomeric, whereas the full extracellular receptors existed as tetramers. All reconstituted receptors retained their ability to bind gp120. The dissociation constant, however, differed drastically from micromolar values for the monomeric receptors to nanomolar values for the tetrameric receptors, suggesting that the repeat region of these receptors contributes to the avidity of gp120 binding. Such oligomerization may provide a mechanism for the receptor to selectively recognize pathogens containing multiple high-mannose-concentration carbohydrates. In contrast, the receptors bound to ICAMs with submicromolar affinities that are similar to those of two nonspecific cell surface glycoproteins, FcγRIIb and FcγRIII, and the oligomerization of DC-SIGNR resulted in no increase in binding affinity to ICAM-3. These findings suggest that DC-SIGN may not discriminate other cell surface glycoproteins from ICAM-3 binding. The pH dependence in DC-SIGN binding to gp120 showed that the receptor retained high-affinity gp120 binding at neutral pH but lost gp120 binding at pH 5, suggesting a release mechanism of HIV in the acidic endosomal compartment by DC-SIGN. Our work contradicts the function of DC-SIGN as a Trojan horse to facilitate HIV-1 infection; rather, it supports the function of DC-SIGN/R (a designation referring to both DC-SIGN and DC-SIGNR) as an antigen-capturing receptor.
Inhibition of Flavivirus Infections by Antisense Oligomers Specifically Suppressing Viral Translation and RNA Replication
Authors: Deas Tia S. , Binduga-Gajewska Iwona , Tilgner Mark , Ren Ping , Stein David A. , Moulton Hong M. , Iversen Patrick L. , Kauffman Elizabeth B. , Kramer Laura D. , Shi Pei-Yong
Published: March 2005

RNA elements within flavivirus genomes are potential targets for antiviral therapy. A panel of phosphorodiamidate morpholino oligomers (PMOs), whose sequences are complementary to RNA elements located in the 5′- and 3′-termini of the West Nile (WN) virus genome, were designed to anneal to important
cis
-acting elements and potentially to inhibit WN infection. A novel Arg-rich peptide was conjugated to each PMO for efficient cellular delivery. These PMOs exhibited various degrees of antiviral activity upon incubation with a WN virus luciferase-replicon-containing cell line. Among them, PMOs targeting the 5′-terminal 20 nucleotides (5′End) or targeting the 3′-terminal element involved in a potential genome cyclizing interaction (3′CSI) exhibited the greatest potency. When cells infected with an epidemic strain of WN virus were treated with the 5′End or 3′CSI PMO, virus titers were reduced by approximately 5 to 6 logs at a 5 μM concentration without apparent cytotoxicity. The 3′CSI PMO also inhibited mosquito-borne flaviviruses other than WN virus, and the antiviral potency correlated with the conservation of the targeted 3′CSI sequences of specific viruses. Mode-of-action analyses showed that the 5′End and 3′CSI PMOs suppressed viral infection through two distinct mechanisms. The 5′End PMO inhibited viral translation, whereas the 3′CSI PMO did not significantly affect viral translation but suppressed RNA replication. The results suggest that antisense PMO-mediated blocking of
cis
-acting elements of flavivirus genomes can potentially be developed into an anti-flavivirus therapy. In addition, we report that although a full-length WN virus containing a luciferase reporter (engineered at the 3′ untranslated region of the genome) is not stable, an early passage of this reporting virus can be used to screen for inhibitors against any step of the virus life cycle.
The Cellular Protein Daxx Interacts with Avian Sarcoma Virus Integrase and Viral DNA To Repress Viral Transcription
Authors: Greger James G. , Katz Richard A. , Ishov Alexander M. , Maul Gerd G. , Skalka Anna Marie
Published: March 2005

The cellular protein Daxx was identified as an interactor with avian sarcoma virus (ASV) integrase (IN) in a yeast two-hybrid screen. After infection, Daxx-IN interactions were detected by coimmunoprecipitation. An association between Daxx and viral DNA, likely mediated by IN, was also detected by chromatin immunoprecipitation. Daxx was not required for early events in ASV replication, including integration, as Daxx-null cells were transduced as efficiently as Daxx-expressing cells. However, viral reporter gene expression from ASV-based vectors was substantially higher in the Daxx-null cells than in Daxx-complemented cells. Consistent with this observation, histone deacetylases (HDACs) were found to associate with viral DNA in Daxx-complemented cells but not in Daxx-null cells. Furthermore, Daxx protein was induced in an interferon-like manner upon ASV infection. We conclude that Daxx interacts with an IN-viral DNA complex early after infection and may mediate the repression of viral gene expression via the recruitment of HDACs. Our findings provide a novel example of cellular immunity against viral replication in which viral transcription is repressed via the recruitment of antiviral proteins to the viral DNA.