bluuebunny/crossref_metadata_2025 huggingface dataset:
Water and ligand entry in myoglobin: Assessing the speed and extent of heme pocket hydration after CO photodissociation
Authors: Goldbeck Robert A. , Bhaskaran Shyam , Ortega Cheri , Mendoza Juan L. , Olson John S. , Soman Jayashree , Kliger David S. , Esquerra Raymond M.
Published: January 2006

A previously undescribed spectrokinetic assay for the entry of water into the distal heme pocket of wild-type and mutant myoglobins is presented. Nanosecond photolysis difference spectra were measured in the visible bands of sperm whale myoglobin as a function of distal pocket mutation and temperature. A small blue shift in the 560-nm deoxy absorption peak marked water entry several hundred nanoseconds after CO photodissociation. The observed rate suggests that water entry is rate-limited by the escape of internal dissociated CO. The heme pocket hydration and geminate recombination yields were found to be the primary factors controlling the overall bimolecular association rate constants for CO binding to the mutants studied. The kinetic analysis provides estimates of 84%, 60%, 40%, 0%, and 99% for the steady-state hydrations of wild-type, H64Q, H64A, H64L, and V68F deoxymyoglobin, respectively. The second-order rate constants for CO and H
2
O entry into the empty distal pocket of myoglobin are markedly different, 8 × 10
7
and 2 × 10
5
M
–1
·s
–1
, respectively, suggesting that hydrophobic partitioning of the apolar gas from the aqueous phase into the relatively apolar protein interior lowers the free energy barrier for CO entry.
The structure of nucleosome assembly protein 1
Authors: Park Young-Jun , Luger Karolin
Published: January 2006

Nucleosome assembly protein 1 (NAP-1) is an integral component in the establishment, maintenance, and dynamics of eukaryotic chromatin. It shuttles histones into the nucleus, assembles nucleosomes, and promotes chromatin fluidity, thereby affecting the transcription of many genes. The 3.0 Å crystal structure of yeast NAP-1 reveals a previously uncharacterized fold with implications for histone binding and shuttling. A long α-helix is responsible for homodimerization via a previously uncharacterized antiparallel non-coiled-coil, and an α/β domain is implicated in protein–protein interaction. A nuclear export sequence that is embedded in the dimerization helix is almost completely masked by an accessory domain that contains several target sites for casein kinase II. The four-stranded antiparallel β-sheet that characterizes the α/β domain is found in all histone chaperones, despite the absence of homology in sequence, structural context, or quaternary structure. To our knowledge, this is the first structure of a member of the large NAP family of proteins and suggests a mechanism by which the shuttling of histones to and from the nucleus is regulated.
Crystal structure of a core spliceosomal protein interface
Authors: Schellenberg Matthew J. , Edwards Ross A. , Ritchie Dustin B. , Kent Oliver A. , Golas Monika M. , Stark Holger , Lührmann Reinhard , Glover J. N. Mark , MacMillan Andrew M.
Published: January 2006

The precise excision of introns from precursor mRNAs (pre-mRNAs) in eukaryotes is accomplished by the spliceosome, a complex assembly containing five small nuclear ribonucleoprotein (snRNP) particles. Human p14, a component of the spliceosomal U2 and U11/U12 snRNPs, has been shown to associate directly with the pre-mRNA branch adenosine early in spliceosome assembly and within the fully assembled spliceosome. Here we report the 2.5-Å crystal structure of a complex containing p14 and a peptide derived from the p14-associated U2 snRNP component SF3b155. p14 contains an RNA recognition motif (RRM), the surface of which is largely occluded by a C-terminal α-helix and a portion of the SF3b155 peptide. An analysis of RNA·protein crosslinking to wild-type and mutant p14 shows that the branch adenosine directly interacts with a conserved aromatic within a pocket on the surface of the complex. This result, combined with a comparison of the structure with known RRMs and pseudoRRMs as well as model-building by using the electron cryomicroscopy structure of a spliceosomal U11/U12 di-snRNP, suggests that p14·SF3b155 presents a noncanonical surface for RNA recognition at the heart of the mammalian spliceosome.
Evidence that Perutz's double-β-stranded subunit structure for β-amyloids also applies to their channel-forming structures in membranes
Authors: Singer S. Jonathan , Dewji Nazneen N.
Published: January 2006

Although there is a growing body of evidence that different amyloidoses may have a similar molecular mechanism in common, the many details of this mechanism are not understood. In this study, we propose that there is a common molecular structure of the primary agents of these diseases, namely a small oligomer of Perutz's cylindrical double-β-stranded subunit for polyglutamine and that this structure, which contains a central water-filled core, can spontaneously integrate into the bilayers of membranes to form aqueous pores. We suggest that this ability to produce permeable channels in appropriate neuronal membranes is a key element in the toxicity of the β-amyloids. One strong criterion for the stability of the Perutz structure for an amyloid is that it contain ≈40 or more amino acid residues. We show here that the neurotoxic Aβ amyloids 1-40 and 1-42, related to Alzheimer's disease, spontaneously enter the membranes of intact erythrocytes and cause their lysis but that Aβ 1-38 and Aβ 1-35, which are not neurotoxic, have no observable effects on erythrocytes, supporting our proposal. Other aspects of the proposed mechanism of cytotoxicity of the β-amyloids are explored.
Computer simulations reveal properties of the cell-cell signaling network at the shoot apex in
Arabidopsis
Authors: de Reuille Pierre Barbier , Bohn-Courseau Isabelle , Ljung Karin , Morin Halima , Carraro Nicola , Godin Christophe , Traas Jan
Published: January 2006

The active transport of the plant hormone auxin plays a major role in the initiation of organs at the shoot apex. Polar localized membrane proteins of the PIN1 family facilitate this transport, and recent observations suggest that auxin maxima created by these proteins are at the basis of organ initiation. This hypothesis is based on the visual, qualitative characterization of the complex distribution patterns of the PIN1 protein in
Arabidopsis
. To take these analyses further, we investigated the properties of the patterns using computational modeling. The simulations reveal previously undescribed properties of PIN1 distribution. In particular, they suggest an important role for the meristem summit in the distribution of auxin. We confirm these predictions by further experimentation and propose a detailed model for the dynamics of auxin fluxes at the shoot apex.
Coupling of cell migration with neurogenesis by proneural bHLH factors
Authors: Ge Weihong , He Fei , Kim Kevin J. , Blanchi Bruno , Coskun Volkan , Nguyen Laurent , Wu Xiangbing , Zhao Jing , Heng Julian Ik-Tsen , Martinowich Keri , Tao Jifang , Wu Hao , Castro Diogo , Sobeih Magdi M. , Corfas Gabriel , Gleeson Joseph G. , Greenberg Michael E. , Guillemot Francois , Sun Yi E.
Published: January 2006

After cell birth, almost all neurons in the mammalian central nervous system migrate. It is unclear whether and how cell migration is coupled with neurogenesis. Here we report that proneural basic helix-loop-helix (bHLH) transcription factors not only initiate neuronal differentiation but also potentiate cell migration. Mechanistically, proneural bHLH factors regulate the expression of genes critically involved in migration, including down-regulation of RhoA small GTPase and up-regulation of doublecortin and p35, which, in turn, modulate the actin and microtubule cytoskeleton assembly and enable newly generated neurons to migrate. In addition, we report that several DNA-binding-deficient proneural genes that fail to initiate neuronal differentiation still activate migration, whereas a different mutation of a proneural gene that causes a failure in initiating cell migration still leads to robust neuronal differentiation. Collectively, these data suggest that transcription programs for neurogenesis and migration are regulated by bHLH factors through partially distinct mechanisms.
Climate change, body size evolution, and Cope's Rule in deep-sea ostracodes
Authors: Hunt Gene , Roy Kaustuv
Published: January 2006

Causes of macroevolutionary trends in body size, such as Cope's Rule, the tendency of body size to increase over time, remain poorly understood. We used size measurements from Cenozoic populations of the ostracode genus
Poseidonamicus
, in conjunction with phylogeny and paleotemperature estimates, to show that climatic cooling leads to significant increases in body size, both overall and within individual lineages. The magnitude of size increase due to Cenozoic cooling is consistent with temperature-size relationships in geographically separated modern populations (Bergmann's Rule). Thus population-level phenotypic evolution in response to climate change can be an important determinant of macroevolutionary trends in body size.
Checkpoint control of mitotic exit—do budding yeast mind the GAP?
Authors: Cooper John A. , Nelson Scott A.
Published: January 2006

Cell cycle checkpoints can delay mitotic exit in budding yeast. The master controller is the small GTPase Tem1, with inputs from a proposed guanine nucleotide exchange factor (GEF), Lte1, and a GTPase-activating protein (GAP), Bub2/Bfa1. In this issue, Fraschini et al. (p. 335) show that GAP activity of Bub2/Bfa1 appears to be dispensable for inactivation of Tem1 in cells. Their results call into question the GTP/GDP switch model for Tem1 activity, as have other results in the past. The paper also focuses attention on the two spindle pole bodies as potential sites for regulation of Tem1.
Orthonormal polynomial wavelets on the interval
Authors: Dai Dao-Qing , Lin Wei
Published: January 2006

We use special functions and orthonormal wavelet bases on the real line to construct wavelet-like bases. With these wavelets we can construct polynomial bases on the interval; moreover, we can use them for the numerical resolution of degenerate elliptic operators.
Remarks on spectra and 𝐿¹ multipliers for convolution operators
Authors: Ba̧k Włodzimierz , Hulanicki Andrzej
Published: January 2006

We prove that the spectrum of a convolution operator on a locally compact group

G
G

by a self-adjoint

L
1

L^1

-function

f
f

is the same on

L
1

(
G
)

L^1(G)

and

L
2

(
G
)

L^2(G)

and consequently on all

L
p

L^p

spaces,

1
≤
p
>
∞
,

1\leq p>\infty ,

if and only if a Beurling algebra contains non-analytic functions on

R

\mathbb {R}

operating on

f
f

into

L
1

L^1

.
Unique factorization in generalized power series rings
Authors: Pommersheim James , Shahriari Shahriar
Published: January 2006

Let

K
K

be a field of characteristic zero and let

K
(
(

R

≤
0

)
)

K((\mathbb {R}^{\leq 0}))

denote the ring of generalized power series (i.e., formal sums with well-ordered support) with coefficients in

K
K

, and non-positive real exponents. Berarducci (2000) constructed an irreducible omnific integer, in the sense of Conway (2001), by first proving that an element of

K
(
(

R

≤
0

)
)

K((\mathbb {R}^{\leq 0}))

that is not divisible by a monomial and whose support has order type

ω
\omega

(or

ω

ω
α

\omega ^{\omega ^\alpha }

for some ordinal

α
\alpha

) must be irreducible. In this paper, we consider elements of

K
(
(

R

≤
0

)
)

K((\mathbb {R}^{\leq 0}))

with support of order type

ω
2

\omega ^2

. The irreducibility of these elements cannot be deduced solely from the order type of their support and, after developing new tools for studying these elements, we exhibit both reducible and irreducible elements of this type. We further prove that all elements whose support has order type

ω
2

\omega ^2

and which are not divisible by a monomial factor uniquely into irreducibles. This provides, in the ring

K
(
(

R

≤
0

)
)

K((\mathbb {R}^{\leq 0}))

, a class of reducible elements for which we have unique factorization into irreducibles.
The hypersurface 𝑥+𝑥²𝑦+𝑧²+𝑡³=0 over a field of arbitrary characteristic
Authors: Crachiola Anthony
Published: January 2006

We develop techniques for computing the AK invariant of domains with arbitrary characteristic. As an example, we show that for any field

k

\mathbf {k}

the ring

k

[
X
,
Y
,
Z
,
T
]

/

(
X
+

X
2

Y
+

Z
2

+

T
3

)

\mathbf {k}[X,Y,Z,T] / (X + X^2 Y + Z^2 + T^3)

is not isomorphic to a polynomial ring over

k

\mathbf {k}

.
Sobolev spaces and the Cayley transform
Authors: Astengo Francesca , Di Blasio Bianca
Published: January 2006

The generalised Cayley transform 

C

\mathcal {C}

from an Iwasawa

N
N

-group into the corresponding real unit sphere 

S

\mathbb {S}

induces isomorphisms between suitable Sobolev spaces

H

α

(

S

)

\mathcal {H}^\alpha (\mathbb {S})

and

H

α

(
N
)

\mathcal {H}^\alpha (N)

. We study the differential of 

C

\mathcal {C}

, and we obtain a criterion for a function to be in 

H

α

(

S

)

\mathcal {H}^\alpha (\mathbb {S})

.
Beneficial Effect of Brewers′ Yeast Extract on Daily Activity in a Murine Model of Chronic Fatigue Syndrome
Authors: Takahashi Takashi , Yu Fei , Zhu Shi-jie , Moriya Junji , Sumino Hiroyuki , Morimoto Shigeto , Yamaguchi Nobuo , Kanda Tsugiyasu
Published: January 2006

The aim of this study was to assess the effect of Brewers′ yeast extract (BYE) on daily activity in a mouse model of chronic fatigue syndrome (CFS). CFS was induced by repeated injection of Brucella abortus (BA) antigen every 2 weeks. BYE was orally administered to mice in a dose of 2 g per kg per day for 2 weeks before injecting BA and for 4 weeks thereafter. We evaluated daily running activity in mice receiving BYE as compared with that in untreated mice. Weekly variation of body weight (BW) and survival in both groups was monitored during the observation period. Spleen weight (SW), SW/BW ratio, percent splenic follicular area and expression levels of interferon‐γ (IFN‐γ) and interleukin‐10 (IL‐10) mRNA in spleen were determined in both groups at the time of sacrifice. The daily activity during 2 weeks after the second BA injection was significantly higher in the treated group than in the control. There was no difference in BW between both groups through the experimental course. Two mice in the control died 2 and 7 days after the second injection, whereas no mice in the treated group died. Significantly decreased SW and SW/BW ratio were observed in the treated mice together with elevation of splenic follicular area. There were suppressed IFN‐γ and IL‐10 mRNA levels in spleens from the treated mice. Our results suggest that BYE might have a protective effect on the marked reduction in activity following repeated BA injection via normalization of host immune responses.
Predictive value of oral colonization by Candida yeasts for the onset of a nosocomial infection in elderly hospitalized patients
Authors: Fanello S. , Bouchara J. P. , Sauteron M. , Delbos V. , Parot E. , Marot-Leblond A. , Moalic E. , Flohicc A. M. Le , Brangerd B.
Published: January 2006

The incidence of nosocomial yeast infections has increased markedly in recent decades, especially among the elderly. The present study was therefore initiated not only to determine the predictive value of oral colonization by yeasts for the onset of a nosocomial Candida infection in elderly hospitalized patients (>65 years), but also to clarify the factors that promote infection and to establish a relationship between the intensity of oral carriage and the onset of yeast infection. During this prospective cohort study, 256 patients (156 women and 100 men with a mean age of 83±8 years) were surveyed for yeast colonization or infection. Samples were collected every 4 days from day 0 to day 16 from four sites in the mouth, and intrinsic and extrinsic factors that might promote infection were recorded for each patient. Pulsed field gel electrophoresis was performed on Candida albicans isolates from all infected patients. Poor nutritional status was observed in 81 % of the patients and hyposalivation in 41 %. The colonization level was 67 % on day 0 (59 % C. albicans) and a heavy carriage of yeasts (>50 c.f.u.) was observed for 51 % of the patients. The incidence of nosocomial colonization reached 6·9 % on day 4 (6·1 % on day 8 and 2·7 % on day 12), and that of nosocomial infection was 3·7 % on day 4 (6·8 % on day 8, 11·3 % on day 12 and 19·2 % on day 16). Of the 35 patients infected, 57 % were suffering from oral candidiasis. The principal risk factors for colonization were a dental prosthesis, poor oral hygiene and the use of antibiotics. The risk factors for infection, in addition to those already mentioned for colonization, were endocrine disease, poor nutritional status, prolonged hospitalization and high colony counts. Genotyping revealed person-to-person transmission in two patients. Thus, this study demonstrates a significant association between oral colonization and the onset of yeast infections in elderly hospitalized patients. Therefore, oral samples should be collected at admission and antifungal treatment should be administered in cases of colonization, especially in patients presenting a heavy carriage of yeasts. Genotyping of the strains confirmed the possibility of person-to-person transmission.
Multilocus sequence typing (MLST) analysis of Vibrio cholerae O1 El Tor isolates from Mozambique that harbour the classical CTX prophage
Authors: Lee Je Hee , Han Kyung Ho , Choi Seon Young , Lucas Marcelino E. S. , Mondlane C. , Ansaruzzaman M. , Nair G. Balakrish , Sack David A. , von Seidlein Lorenz , Clemens John D. , Song Manki , Chun Jongsik ,   The Mozambique Cholera Vaccine Demonstration Project Coordination Group, Kim Dong Wook
Published: January 2006

Vibrio cholerae O1 isolates belonging to the Ogawa serotype, El Tor biotype, harbouring the classical CTX prophage were first isolated in Mozambique in 2004. Multilocus sequence typing (MLST) analysis using nine genetic loci showed that the Mozambique isolates have the same sequence type (ST) as O1 El Tor N16961, a representative of the current seventh cholera pandemic. Analysis of the CTX prophage in the Mozambique isolates indicated that there is one type of rstR in these isolates: the classical CTX prophage. It was also found that the ctxB-rstR-rstA-rstB-phs-cep fragment was PCR-amplified from these isolates, which indicates the presence of a tandem repeat of the classical CTX prophage in the genome of the Mozambique isolates. The possible origin of these isolates and the presence of the tandem repeat of the classical prophage in them implicate the presence of the classical CTX phage.
Wage inequality and overeducation in a model with efficiency wages
Authors: Skott Peter
Published: January 2006

Abstract. This paper shows that the existence and persistence of ‘overeducation’ can be explained by an extension of the efficiency wage model. When calibrated to fit the amounts of overeducation found in most empirical studies, the model implies that both the relative wage and the relative employment of high‐skill workers depend inversely on aggregate economic activity. Keeping aggregate employment constant, furthermore, low‐skill unemployment rises, following an increase in the relative supply of high‐skill labour, and relative wages may be insensitive to changes in relative labour supplies. The model may help to explain rising wage inequality in some countries since the early 1970s. JEL classification: J31
Populations of trout and grayling in two Scottish rivers
Authors: Mackay David W.
Published: January 2006

Major pollutions resulted in the deaths of all fish in 8 km long stretches of two trout streams in central Scotland. Fish were collected, measured and weighed and the ages established by scale‐reading. The predominant species present were Salmo trutta (L.) and Thymallus thymallits (L.) with about five times as many trout as there were grayling in each stream. The Douglas Water, which was previously unpolluted, held five times as many fish as the River Gryfe which had a history of intermittent pollution. The trout and grayling of the River Gryfe grew faster than those from the Douglas Water and there were more of the larger sizes present.
Gobius cmentatus—a fish new to the northern European fauna
Authors: Wheeler Alwyne
Published: January 2006

Three occurrences of the goby Gobius (Macrogobius) cruentatus in the southwestern region of Ireland are recorded. This species had previously been recorded as far north as southern Biscay. The range of the species is discussed, a full description of the three Irish specimens, and details of its distinguishing features are given. A key to the British species of the genus Gobius is given. The discussion compares the occurrence of this species with the distribution of other Lusitanian fishes and invertebrates on the Irish coast.
Response of the seminal vesicles of the hypophysectomized catfish Heteropneustes fossilis (Bloch) to exogenous androgens, estrogen and corticosteroid†
Authors: Nayyar S. K. , Sundararaj Bangalore I.
Published: January 2006

The response of the regressed seminal vesicles of 136‐ and 102‐day hypophysectomized catfish to 30‐day treatment with various steroids has been studied. Hypophysectomy results in complete regression of the seminal vesicles within 40 days. Of the various andro gens tested, ethynyltestosterone and 17 α‐methyltestosterone are equipotent in producing weight increment and initiation of secretory activity in the regressed seminal vesicles but are 2.5 times more potent than testosterone propionate. Olive oil, eslradiol benzoate and desoxycorticosterone acetate treatment induce neither secretory activity nor weight increments in the regressed seminal vesicles. The adrenal androgens, 4‐androstenedione and dehydroepiandrosterone proved to be weak androgens. The data indicate that only androgens can restore secretory activity in the regressed seminal vesicles of the hypophy sectomized catfish.
‘Bald spot’ disease in powan Coregonus lavaretus (L.)
Authors: Roberts R.J. , Leckie J. , Slack H. D.
Published: January 2006

The stocks of powan Coregonus lavaretus (L.) in Loch Lomond (Scotland) were affected by an acute no‐ulcerative inflammatory lesion in the centre of the head, at the same time as ulcerative dermal necrosis (U.D.N.) became apparent in salmon in the Loch. The numbers of powan were very great at the time, and fish were of poor quality and frequently fungus‐infected. No pathogen was isolated from the lesions which rarely contained fungus, and were histologically very different from the lesions of U.D.N. in salmon. Its disappearance by the following year, coincided with a marked improvement in quality of the fish.
Mycological aspects of a disease of young perch in Windermere
Authors: Wllloughby L. G.
Published: January 2006

A disease of young perch in Windermere was investigated. In contrast to the case of U.D.N. infections of salmon and trout, a variety of fungi were obtained from the diseased fish. These reflected the spora present in the water at the same time to a large extent. An exception was Saprolegnia ferax, which did not grow on the fish and indicated that some degree of host specificity was involved. The Achyla isolates, both from the fish and from the water, were found to be heterothallic and male in reaction.
Study of the haemoglobin content of a single erythrocyte (M index) in various cultured fish species
Authors: Molnár Gy. , Tamássy E.
Published: January 2006

Investigations of the erythrocyte count, haemoglobin content and M index of 7 fish species were performed under equivalent environmental conditions in the same period of the year. The species were: bighead Hypophthalmichthys nobilis (Richardson), carp Cyprinus carpio L., silver carp Hypophthalmichthys molitrix (Val.), grass carp Ctenopharyngodon idella (Val.), sheat‐fish Silurus glanis L., pike Esox Indus L., pike‐perch Lucioperca lucioperca (L.). Bighead and carp are carnivorous and omnivorous, silver carp and grass carp are herbivorous and sheat‐fish, pike and pike‐perch are predatory. Significant differences were demonstrable between M values of fish living on different type of food, where the M index is:

image

It is concluded that M index values are useful as one parameter differentiating between fish with distinctly different food habits.
The occurrence of Argulus (Crustacea: Branchiura) in Scotland
Authors: Campbell A. D.
Published: January 2006

Records of the distribution of the genus Argulus in Scotland are given. The occurrence of A. coregoni Thorell in the River Clyde is confirmed.
An air‐economizer apparatus for use in fish work
Authors: Abram F. S. H.
Published: January 2006

Cylinders of compressed air are usually employed to aerate fish stock tanks located away from a source of mains electricity.

The apparatus described drives a compressor by extracting some of the energy contained within the high‐pressure air from the cylinder by expanding it through an engine, and recovering the power produced. The compressor draws air from the atmosphere to supply a reservoir used to aerate the tanks, at about 0–2 atmospheres. The volume of air obtained is five to six times that available when an air cylinder is connected direct to the aeration system.
Feeding and digestion in two cottid fishes, the freshwater Cottus gobio L. and the marine Enophrys bubalis (Euphrasen)
Authors: Western J. R. H.
Published: January 2006

A comparative study of feeding and digestion in the freshwater Cuttus gobio and the marine Enoghrys bubnlis has been made. The digestion of live prey taken voluntarily, and of aqueous starch suspensions and of olive oil administered by stomach tube, are described at the macroscopic and histological level. Particular attention has been paid to the food capacity of the gut, the mechanical treatment of the food, and the role of mucus in the alimentary tract.

Digestion, which is similar in the two species, is divided into three distinct phases, corresponding to the three morphologically separate regions of the post‐pharyngeal gut. The relative roles of each of the three regions in the digestion and absorption of food are assessed.

No modification of gut structure or function in either species directly attributable to environmental salinity has been detected. The evidence suggests that the faster growth rate of the marine species may be due to the greater digestive‐absorptive capacity of its digestive system.
The effect of acute X‐irradiation on the development of the plaice Pleuronectes platessa L.
Authors: Ward Eileen , Beach S. A. , Dyson E. D.
Published: January 2006

Plaice eggs were irradiated with 80 kV peak X‐rays at 5 % of their development from fertilization to hatching. The range of doses used was approximately 30–150 rads and the doses were measured with thermoluminescent dosimeters. The percentage hatch of eggs, survival of 3‐week old larvae and survival to metamorphosis were noted. The results show that at one of the most radiosensitive stages of development, the LD50/metamorphosis for plaice is approximately 90 rads. There is a steep response curve where a dose of 30 rads has little effect and where doses above 150 rads kill the majority of the larvae before metamorphosis.
Thermal selection behaviour in the estuarine goby Gillichthys mirabilis Cooper
Authors: de Vlaming Victor L.
Published: January 2006

The estuarine goby Gillichthys mirabilis behaviorally thermoregulates when placed in a laboratory temperature gradient. Avoidance of temperatures above 23°C is the most evident component of this thermotaxis. Temperature preferences of non‐acclimated fish do not vary significantly as a function of season; nor does temperature acclimation alter the preferendum. Varying the temperature range of the gradient apparently modifies thermotaxis. Negative phototaxis evidenced by this species is subjugated by thermal preferences. Temperature preference does not vary diurnally. The heat resistance of this species was determined; there is no apparent relationship between heat resistance and temperature preference.
An investigation of the advantages of autumn and spring stocking with brown trout Salmo trutta L. in a Yorkshire reservoir
Authors: Templeton R. G.
Published: January 2006

Batches of trout have been introduced into Chelker Reservoir in Yorkshire in the autumn and spring since the 1870's for angling purposes. Six batches of tagged, hatchery‐reared brown trout Salmo trutta L. were introduced from autumn 1966 to spring 1969. During the angling season fish introduced in the spring give better catches than those stocked in the autumn. At the beginning of the season the larger fish in the spring batch are caught more often than the smaller fish from the same batch. The larger fish in the autumn batch are caught more often than the smaller fish from that batch throughout the season. The population, available to the angler from the shore was estimated to be 1491 in 1968, with 722 fish/km of shoreline. More fish survive to a second year in the reservoir than is apparent from the number of tags returned. Fish introduced in the spring usually begin growing before those introduced in the autumn, thereafter growth rates varied. The growth rate was independent of the number offish stocked up to the numbers put in.

Batches of tagged trout were retained at the hatchery up to nine months to gain relevant experience of post‐tagging mortalities, tag loss rate and effect of tags on growth.
A rapid volumetric method for the analysis of the food of fishes
Authors: Hellawell J. M. , Abel R.
Published: January 2006

A volumetric method in which the stomach contents are squashed to a uniform depth and the volume is derived from the area of the squash has been evaluated. The apparatus is simple in constiuction and the method applicable to a wide range of fish sizes. The overall error of the method may be as low as 3.5 % for well macerated material, though for hard bodied food animals the coefficient of variation may be up to 8 %. These volumetric determinations are not directly proportional to gravimetric measurements but logarithmic conversion curves are readily derived.
The age and growth of perch (Perca fluviatilis L.) in two Scottish lochs
Authors: Shafi Muhammed , Maitland Peter S.
Published: January 2006

This study is concerned with the age and growth of perch (Perca fluviatilis L.) in two contrasting Scottish lochs‐the Dubh Lochan and Loch Lomond. Age and back‐calculated growth were determined from annual rings in the opercular bones, and during the 2‐year project 470 perch from the Dubh Lochan and 796 from Loch Lomond were examined. Growth in length in the two lochs, though similar for the first 2 years, differed thereafter, the average length at 8 years in the Dubh Lochan being less than 15 cm, that in Loch Lomond more than 23 cm at the same age. In neither locality did the growth of perch follow the Von Bertalanffy growth formula. Reasons for differential growth rates are discussed and comparisons made with the growth of perch in other waters in Europe and North America.
A sonar fish counter
Authors: Braithwaite H.
Published: January 2006

The basic principles of a new technique for counting fish moving up or down stream are given. The counter is based on the ability to detect the presence of fish in an acoustic beam directed across the river. The counter is capable of counting several fish moving up or down stream simultaneously and is designed for use in wide open channels. The results of field trials with the equipment at two different sites are discussed together with the problems encountered. The results obtained are in good agreement with other methods of counting fish but the totals obtained were insufficient to put confidence limits on the counter.
Flounder Parasites as Biological Tags
Authors: Gibson David I.
Published: January 2006

The use of fish‐parasites as biological tags may become an efficient method of tracing the origin of some migratory fish. The helminth parasites of flounders Platichthys flesus (L.) from 2 estuaries and from the sea within a 40 mile range were recorded, and an attempt was made to explain the level of infestation of each species of parasite in the 3 localities in relation to their life‐history and the physical nature of the environment. The flounders from the 3 localities were shown to have dissimilar parasite‐faunas, and, therefore, it was possible to characterize the parasite‐fauna for each of the 3 groups of flounders. Individual fish from each locality could be recognized by its parasite‐fauna and especially by the level of certain indicator‐parasites. Similarly, “foreign” flounders moving into a flounder population could be picked out by the markedly different composition of their parasite‐fauna. Podocotyle sp. and Zoogonoides viviparus were useful indicator‐parasites in this instance.
Plasma chemical composition in the goosefish (Lophius piscatorius, L)
Authors: Palacios L. , Rubio M. , Planas J.
Published: January 2006

124 specimens of Lophius piscatorius, L. have been studied (22 males, 90 immature females and 12 sexually mature females) from the Mediterranean coast between October 1968 and February 1971. The plasma values of total proteins, Cl‐, K+, Na+, plasma iron, total iron binding capacity and plasma copper have been determined. These values are related to weight, length, sex and sexual maturity, depth of trawl and season of the year. The electrolyte content is somewhat lower than given for this species. A clear seasonal variation is observed, with a decrease in the plasma electrolyte. The iron and copper plasma and TIBC values agree with the few values previously recorded and it is thought that they will be of interest due to the scarcity of data on fish.
A neotype and 2 topotypes for Bola chaptis Hamilton, 1822 (Pisces, Sciaenidae)
Authors: Talwar P. K. , Datta A. K.
Published: January 2006

Hamilton (1822) described and figured Bola chaptis from the River Ganges, but left no type material. Trewavas & Talwar (1972, p. 11) have described a species that they believe identical with B. chaptis and placed it in the genus Bahaba Herre. Since their specimens came from Burma they did not propose a neotype from among them. During the course of a taxonomic study of the family Sciaenidae, 3 well‐preserved specimens in the collections of the Zoological Survey of India were recognized by us as the same species. They were collected by the junior author at Chinsura in the Hooghly estuary during September 1954. This discovery supports the decision of Trewavas and Talwar to use Hamilton's name and after consultation with Dr Trewavas we have decided to select one of these specimens as neotype of Bahaba chaptis (Hamilton).
The existence of natural hybrids between the European trout and the Atlantic salmon
Authors: Payne R. H. , Child A. R. , Forrest A.
Published: January 2006

Natural hybrids between Atlantic salmon (Salmo salar L.) and European trout (S. trutta L.) have been detected in a sample of 4431 fish which appeared to be Atlantic salmon. The methods of analysis for serum protein, serum esterase and serum lactic dehydrogenase are given. The possible occurrence of hybrids having the appearance of European trout and the effect of introgression on salmon stocks are discussed.
Evaluation of the contribution of supplemental plantings of brown trout Salmo trutta (L.) to a self‐sustaining fishery in the Sydenham River, Ontario, Canada
Authors: Millard Timothy J. , MacCrimmon Hugh R.
Published: January 2006

An autumn planting of 4000 tagged yearling brown trout Salmo trutta (L.) in 1969 resulted in an over‐winter survival of 26%, an angler recovery the following year of 8·1 % and made up 22 % of the March, 1970 standing population of the species. August standing populations of brown trout increased from 142 trout/ha (17·6 kg/ha) in 1969 to 360 trout/ha (39·3 kg/ha in 1970 while angler harvest of the species increased from 61 trout/ha (12·7 kg/ha) at a rate of 0·26 fish/h to 89 trout/ha (18·5 kg/ha) at a rate of 0·34/h. Using angler recovery and standing population as criteria the planting contributed substantially to the fishery. Actual contribution of stocked trout however, is questioned after detailed analysis of resident population structure and the potential of natural recruitment. It is suggested that the true benefit of stocked trout may be measured by the presence of those stocked fish in excess of the number of resident trout of that size predictable from a normal length distribution curve in waters with self‐sustaining populations. Complexities in evaluating the merits of supplemental plantings of hatchery‐reared brown trout to existing stream fisheries are examined.
Observations on the blood physiology of five South African freshwater fish
Authors: Hattingh J.
Published: January 2006

Various parameters of the blood physiology of five South African species of fish have been investigated. The results show that plasma and serum samples differ in electrophoretic pattern, and also in the number of fractions and the protein concentration of these fractions. Red blood cell measurements, hemoglobin concentrations and blood glucose concentrations differ from fish to fish, and appear to be species specific. The values reported here are comparable with similar results obtained by other workers.
Partial separation of the pituitary proteins of Labeo umbratus, Smith (mudfish)
Authors: Hattingh J. , du Toit P. J.
Published: January 2006

L. umbratus pituitary glands were partially separated by means of preparative polyacry‐lamide electrophoresis and chromatography on DEAE‐cellulose and Sephadex G‐50. Eight fractions were obtaìned and it was found that fraction 1 contained potent adrenocorticotropic stimulating activity, with a molecular weight in the region of 6000. Fractions 3 and 4 contained potent gonadotropic and a lesser degree of exopthalmic producing activity, with molecular weights in the region of 14 000 to 20 000. Fraction 6 displayed pigeon‐crop stimulating activity, with a molecular weight above 30 000. Fractions 7 and 8 displayed M.S.H. and vasopressinoxytocic activity respectively, with a molecular weight in the region of 5500–6500. Fractions 2 and 5 could not be identified. The fractions seemed to be glycoproteins and the results are discussed in relation to previous findings.
The effect of size of food ration on egg production in the female three‐spined stickleback, Gasterosteus aculeatus L.
Authors: Wootton R. J.
Published: January 2006

The effect of food level on the egg production of three‐spined sticklebacks was studied experimentally. High food levels increased the percentage of fish that matured, and the weight of the fish at maturity. Weight at maturity was positively correlated with the number of spawnings, the mean number and the weight of eggs produced per spawning. Food level had no effect on the size of the eggs, whether size was expressed as wet or dry weight per egg. Fish on the highest food level spawned at shorter intervals than fish at the lower levels. A preliminary model of the effect of food supply on recruitment to a stickleback population is nresented.
Studies on the skin of plaice (Pleuronectes platessa L.)
Authors: Roberts Ronald J. , Bell Marcus , Young Hamish
Published: January 2006

Histological and ultrastructural examinations were carried out on the integuments of larval plaice from hatching to 60 days. The skin of the newly hatched larva consisted of a delicate epidermis overlying a fluid filled dermal space. As the fish matured this became thicker, the fibrous dermis developed and the mitochondrion rich ‘chloride cells’ degenerated. Around the 42nd day the eosinophil granule cell appeared in the basal layers of the epidermis and by the sixtieth day the epidermis could be considered fully developed.
A report on the artificial fertilization of the smallmouth yellowfish, Barbus holubi (Steindachner, 1894)
Authors: Mulder P. F. S. , Franke G. W.
Published: January 2006

Artificial fertilization was successfully applied in the culture of Barbus holubi. By this method the fertilization potential was raised considerably and the mortality rate under normal conditions during the incubation period was less than 5 %. The handling and transferring of larvae to fertilized rearing ponds was simplified and an estimation of the seasonal production could be made without waiting for the fish to attain the fingerling stage. Normal breeding activities were not disturbed by frequent handling and natural breeding took place in ponds where the fish were kept.
The immune responses of dace Leuciscus leuciscm (L.) to injected antigenic materials
Authors: Harris J. E.
Published: January 2006

The fundamental features of the primary responses of dace Leuciscus leuciscus (L.), a freshwater cyprinid, to a number of standard antigens—haemocyanin, bovine serum albumin, horse serum, a bacterial antigen and an erythrocyte suspension, were examined. The fish were capable of producing either precipitating or agglutinating antibody in response to each of these antigens. Determinations of latent periods of antibody production by dace over a range of temperatures −18, 10, 5 and 2°C, showed that although the latent periods of the primary response increased with decreasing temperature, fish were able to produce antibodies to the erythrocyte antigen at 2°C and to the Salmonella and horse serum protein antigens at 5°C. The demonstration of antibodies at 5 and 2°C suggests that the fish are capable of producing antibodies over the complete range of their normal environmental temperatures.
Overwinter feeding in rainbow trout
Authors: Hunt P. C. , O'Hara K.
Published: January 2006

The contents of the stomachs of 38 rainbow trout stocked in Llyn Alaw, Anglesey, in August 1969 and caught between October 1969 and February 1970 were analysed. The fish were actively feeding on the bottom fauna throughout the winter and 21 of the stomachs were full or distended. The mean volume of the contents of the stomachs was 2–8 times greater than that of the contents of stomachs of similarly sized brown trout caught at the same time.
The species of Pseudaphya (Teleostei: Gobiidae) and the evolution of aphyiine gobies
Authors: Miller P. J.
Published: January 2006

The Mediterranean gobiid genus Pseudaphya Iljin, 1930, formerly containing two nominal species, the type Ps. ferreri (O. De Buen & Page, 1908) and Ps. pelagica De Buen, 1931, is now believed to be monotypic after examination of Adriatic material originally identified as Gobius pusillus Canestrini, 1861. The last is here provisionally regarded as Pomato‐schistus knerii (Steindachner, 1861). The genus Pseudaphya is redefined, with additional osteological features, and its single species, Ps. ferreri, redescribed. In comparison with other small transparent gobiids, Pseudaphya is shown to possess certain primitive features and a possible mode of evolution for this group of tiny gobies by neoteny from postlarvae of hill‐stream sicydiines is discussed. An origin from less specialized gobiines seems more acceptable.
The ecology of young turbot, Scophthalmus maximus (L.), at Borth, Cardiganshire, Wales
Authors: Jones A.
Published: January 2006

The ecology of 0‐ and 1‐group turbot was studied at Borth, Cardiganshire, during the years 1966–68. Newly‐metamorphosed turbot appeared in the surf zone from July to October, Abundance during the period September 1967 to May 1968 decreased at an average rate of 25% of the sampled population per month. Fish of the 1966 year‐class grew from a mean length of 4.5 cm in September 1966 to 14.4 cm in October 1967. Growth was fast in the spring and summer, slowing during the late autumn and winter. The most important food items of 0‐ and 1‐group turbot by percentage occurrence and dry weight were polychaetes and mysids. The daily food intake of 0‐group turbot in September 1967 was estimated as 2.5 % of the body weight per day.
Metazoan parasites of salmonids and coregonids from coastal Labrador*
Authors: Hicks Franklin J. , Threlfall William
Published: January 2006

Three hundred and twenty‐three fish of six species (salmonids and coregonids) from four locations on the eastern coast of Labrador were examined for metazoan parasites, using conventional parasitological techniques. Twenty‐four genera of parasites were recovered (3 of Monogenea, 8 of Digenea, 5 of Cestoda, 5 of Nematoda, 1 of Acanthocephala, 2 of parasitic Copepoda). Fifty‐one new host records were noted. Fourteen genera of parasites were noted in Salmo salar L., while Salvelinus fontinalis (Mitchill) contained 21 genera; S. namaycush (Walbaum,) 12 genera; S. alpinus (L.), 16 genera: Coregonus clupeaformis (Mitchill), 11 genera; Prosopium cylindraceum (Pallas), 11 genera. It was found that the parasite burden of the various fish species examined was not homogeneous when sample areas and sex of the fish was considered. An increase in the number of parasite species per infected host with age was seen in the case of Salmo salar, Salvelinus fontinalis, S. namaycush, S. alpinus. In Coregonus clupeaformis and Prosopium cylindraceum no such correlation was seen, this difference being related to the ecology of the fish. The parasitofauna of the various salmonid species examined was not homogeneous, significant differences being noted in the number of certain species infected with specific parasites. Significant differences were also noted in the parasite burden of the Salmonidae when compared with the Coregonidae. Food items recovered from the fish autopsied were noted.
The effect of exogenous hormone treatment on spermiation and vitellogenesis in the grey mullet, Mugil cephalus L.
Authors: Shehadeh Ziad H. , Madden William D. , Dohl Thomas P.
Published: January 2006

The effects of mammalian gonadotropins, methyltestosterone and partially purified salmon gonadotropin on spermiation and oocyte maturation were studied in adult grey mullet. Methyltestosterone was a potent spermiating agent in both prespawning and spawning trials. The most effective dose was 5 mg/100 g body weight. Human chorionic gonadotropin (HCG) was moderately effective at a dose rate of 20 IU/100 g body weight. Both hormones blocked resorption of milt in captive animals. The HCG, FSH/LH combination, Synahorin+mullet pituitary homogenate, and partially purified salmon gonadotropin were equally effective, at the doses used, in inducing oocyte maturation and preventing onset of atrophy before completion of vitellogenesis. Atrophy occurred in all experimental fish at mean oocyte diameter of 750 μ. The significance of this finding is discussed. (Oceanic Institute Contribution No. 98).
Temperature and salinity tolerance of juvenile Rhabdosargus holubi [Steindachner (Teleostei: Sparidae)]
Authors: Blaber Stephen J. M.
Published: January 2006

Temperature and salinity tolerances of juvenile Rhabdosargus holubi (Steindachner) were determined experimentally. Results indicated that they are tolerant over a wide range of salinities (0.7–70‰) and temperatures (10–30°C) and that little interaction between temperature and salinity occurs. R. holubi is restricted to the warm temperate waters of southeastern Africa. It is absent from the subtropical Indian Ocean and from temperate Atlantic Ocean waters. The juveniles occur mainly in the inshore waters and estuaries. Evidence from tolerance experiments and salinity and temperature data from southern African estuaries suggested that the distribution of R. holubi is controlled by temperature.
Aquarium studies on the consumption of small animals by O–group grass carp, Ctenopharyngodon idella (Val.)
Authors: Edwards D. J.
Published: January 2006

In aquarium experiments common invertebrates from streams and ponds were offered to O‐group grass carp, Ctenopharyngodon idella (Val.) in the presence of palatable plants. When there was no cover for the prey to hide under, the carp ate many of the invertebrates, but when stones were provided, considerably more invertebrates escaped. Rainbow trout eggs were not eaten, but trout fry were taken as soon as they had emerged from artificial spawning redds. While searching for food, grass carp never disturbed the stones covering possible food organisms.