bluuebunny/crossref_metadata_2025 huggingface dataset:
Wild chimpanzees show population-level handedness for tool use
Authors: Lonsdorf Elizabeth V. , Hopkins William D.
Published: August 2005

Whether nonhuman primates exhibit population-level handedness remains a topic of considerabe theoretical and empirical debate. One continued subject of discussion is whether evidence of population-level handedness in primates is confined to studies in captive animals or whether it is in both captive and wild subjects. Here, we report evidence of population-level handedness in wild chimpanzees for a tool-use task known as “termite-fishing.” We subsequently compared the handedness for termite-fishing with other published reports on handedness for nut-cracking and wadge-dipping and found task-specific differences in handedness. Last, when combing all of the published data on tool use in wild chimpanzees, we show that hand preferences are heritable. Contrary to previous claims, our results demonstrate that populationlevel handedness is evident in wild chimpanzees and suggest that the antecedents of lateralization of function associated with hand use were present at least 5 million years ago, before thePan-Homosplit.
Regulation of a
Bacillus subtilis
mobile genetic element by intercellular signaling and the global DNA damage response
Authors: Auchtung Jennifer M. , Lee Catherine A. , Monson Rita E. , Lehman Alisa P. , Grossman Alan D.
Published: August 2005

Horizontal gene transfer contributes to the evolution of bacterial species. Mobile genetic elements play an important role in horizontal gene transfer, and characterization of the regulation of these elements should provide insight into conditions that influence bacterial evolution. We characterized a mobile genetic element, ICE
Bs1
, in the Gram-positive bacterium
Bacillus subtilis
and found that it is a functional integrative and conjugative element (ICE) capable of transferring to
Bacillus
and
Listeria
species. We identified two conditions that promote ICE
Bs1
transfer: conditions that induce the global DNA damage response and crowding by potential recipients that lack ICE
Bs1
. Transfer of ICE
Bs1
into cells that already contain the element is inhibited by an intercellular signaling peptide encoded by ICE
Bs1
. The dual regulation of ICE
Bs1
allows for passive propagation in the host cell until either the potential mating partners lacking ICE
Bs1
are present or the host cell is in distress.
Role of Pam16's degenerate J domain in protein import across the mitochondrial inner membrane
Authors: D'Silva Patrick R. , Schilke Brenda , Walter William , Craig Elizabeth A.
Published: August 2005

Translocation of proteins across the mitochondrial inner membrane is an essential process requiring an import motor having mitochondrial Hsp70 (mtHsp70) at its core. The J protein partner of mtHsp70, Pam18, is an integral part of this motor, serving to stimulate the ATPase activity of mtHsp70. Pam16, an essential protein having an inactive J domain that is unable to stimulate mtHsp70's ATPase activity, forms a heterodimer with Pam18, but its function is unknown. We set out to test the importance of three properties of Pam16: (
i
) a stable interaction between Pam16 and Pam18, (
ii
) the inability of Pam16's degenerate J domain to stimulate Ssc1's ATPase domain, and (
iii
) the innately lower stimulatory activity of the Pam16:Pam18 heterodimer, compared to Pam18 alone. Neither substantial reduction in the ability of Pam18 to stimulate Ssc1's ATPase activity, nor the presence of an active J domain in Pam16, had deleterious effects on cell growth, indicating the lack of importance of two of these biochemical properties. However, a stable interaction between Pam16's degenerate J domain and Pam18's J domain was found to be critical for function. Alterations that destabilized the Pam16:Pam18 heterodimer had deleterious effects on cell growth and mitochondrial protein import; intragenic suppressors that restored robust growth also restored heterodimer stability. Our results support the idea that Pam16's J-like domain strongly interacts with Pam18's J domain, leading to a productive interaction of Pam18 with mtHsp70 at the import channel.
Pork meat increases iron absorption from a 5-day fully controlled diet when compared to a vegetarian diet with similar vitamin C and phytic acid content
Authors: Kristensen Mette Bach , Hels Ole , Morberg Catrine , Marving Jens , Bügel Susanne , Tetens Inge
Published: August 2005

Meat increases absorption of non-haem iron in single-meal studies. The aim of the present study was to investigate, over a 5 d period, the potential increasing effect of consumption of pork meat in a whole diet on the fractional absorption of non-haem iron and the total absorption of iron, when compared to a vegetarian diet. A randomised cross-over design with 3×5 d whole-diet periods with diets containing Danish-produced meat, Polish-produced meat or a vegetarian diet was conducted. Nineteen healthy female subjects completed the study. All main meals in the meat diets contained 60 g of pork meat and all diets had high phytic acid content (1250 μmol/d). All main meals were extrinsically labelled with the radioactive isotope59Fe and absorption of iron was measured in a whole body counter. The non-haem iron absorption from the Danish meat diet was significantly higher compared to the vegetarian diet (P=0·031). The mean fractional absorption of non-haem iron was 7·9 (se1·1), 6·8 (se 1·0) and 5·3 (se 0·6) % for the Danish and Polish meat diets and vegetarian diet, respectively. Total absorption of iron was higher for both meat diets compared to the vegetarian diet (Danish meat diet:P=0·006, Polish meat diet:P=0·003). The absorption ratios of the present study were well in accordance with absorption ratios estimated using algorithms on iron bioavailability. Neither the meat diets nor the vegetarian diets fulfilled the estimated daily requirements of absorbed iron in spite of a meat intake of 180 g/d in the meat diets.
Comparative2H-labelled α-tocopherol biokinetics in plasma, lipoproteins, erythrocytes, platelets and lymphocytes in normolipidaemic males
Authors: Jeanes Yvonne M. , Hall Wendy L. , Lodge John K.
Published: August 2005

The biokinetics of newly absorbed vitamin E in blood components was investigated in normolipidaemic males. Subjects (n12) ingested encapsulated 150 mg2H-labelledRRR-α-tocopheryl acetate with a standard meal. Blood was collected at 3, 6, 9, 12, 24 and 48 h post-ingestion.2H-Labelled and pre-existing unlabelled α-tocopherol (α-T) was determined in plasma, lipoproteins, erythrocytes, platelets and lymphocytes by LC–MS. In all blood components, labelled α-T concentration significantly increased while unlabelled decreased following ingestion (P<0·0001). Significant differences in labelled α-T biokinetic parameters were found between lipoproteins. Time of maximum concentration was significantly lower in chylomicrons, while VLDL had a significantly greater maximum α-T concentration and area under the curve (AUC) (P<0·05). The largest variability occurred in chylomicron α-T transport. Erythrocyte labelled α-T concentrations increased gradually up to 24 h while α-T enrichment of platelets and lymphocytes was slower, plateauing at 48 h. Platelet enrichment with labelled α-T was biphasic, the initial peak coinciding with the labelled α-T peak in chylomicrons. Erythrocyte and HDL AUC were significantly correlated (P<0·005), as was platelet and HDL AUC (P<0·05). There was a lower turnover of pre-existing α-T in platelets and lymphocytes (maximum 25 % labelled α-T) compared to plasma and erythrocytes (maximum 45 % labelled α-T). These data indicate that different processes exist in the uptake and turnover of α-T by blood components and that chylomicron α-T transport is a major determinant of inter-individual variation in vitamin E response. This is important for the understanding of α-T transport and uptake into tissues.
Influence of flavomycin on microbial numbers, microbial metabolism and gut tissue protein turnover in the digestive tract of sheep
Authors: Edwards Joan E. , Bequette Brian J. , McKain Nest , McEwan Neil R. , Wallace R. John
Published: August 2005

Flavomycin is an antibiotic that promotes growth in ruminant and non-ruminant livestock. The aim of this study was to determine the mechanism of action of flavomycin in sheep by measuring microbial numbers, microbial metabolism and gut tissue protein turnover at different sites in the digestive tract. Two weight-matched groups (n5) of male castrate lambs (30 kg) received 800 g grass cubes/d for 6 weeks, with one group receiving 20 mg/d flavomycin during the last 2 weeks. Samples of digesta and gut tissue segments were obtained immediatelypost mortem, 90 min after a flood-dose of [ring-D5]phenylalanine. Viable bacterial counts and volatile fatty acid concentrations were highest in ruminal digesta, followed by the colon and caecum, then the duodenum and ileum. The only effect of flavomycin was an increased bacterial count in the rumen (3·5v.1·2×109per g;P=0·04). Acetate was proportionally greater and propionate and butyrate were lower in the caecum and colon than the rumen. Flavomycin had no effect on volatile fatty acid proportions or ammonia concentrations. Bacteria growing on peptides as sole C source were not affected by flavomycin. Proteolytic, peptidolytic and amino acid deamination activities were similar in the rumen, caecum and colon; they tended to be lower in animals receiving flavomycin. Protein turnover in ruminal wall and duodenal tissues, measured by a flood-dose technique, decreased with flavomycin (P=0·075 and 0·027, respectively). Thus, flavomycin differs from ionophores in its mode of action. It may influence protein metabolism of both digesta and tissue throughout the ruminant digestive tract.
Propionate precursors and other metabolic intermediates as possible alternative electron acceptors to methanogenesis in ruminal fermentationin vitro
Authors: Newbold C. J. , López S. , Nelson N. , Ouda J. O. , Wallace R. J. , Moss A. R.
Published: August 2005

Fifteen potential precursors of propionate were tested for their ability to decrease CH4production by ruminal fluidin vitro.Sodium acrylate and sodium fumarate produced the most consistent effects in batch cultures, with 50 % of the added precursors being fermented to propionate and CH4production decreasing by between 8 and 17 %, respectively. Additives were more effective when added as free acids, but this also decreased the pH and may have inhibited fibre digestion. Changing the dietary substrate from predominantly grass hay to predominantly concentrate had no influence on the effectiveness of acrylate and fumarate. In anin vitrofermentor (the rumen simulating technique, Rusitec) with a grass hay—concentrate (50:50, w/w) diet as substrate, both compounds were again fermented to propionate (33 and 44 % conversion to propionate, respectively). However, fumarate appeared more effective as a H2sink compound. It was calculated to capture 44 % of the H2previously used for CH4formation compared with a 22 % capture of H2with acrylate. Fumarate also caused a stimulation in fibre digestion. Thus, sodium fumarate was the preferred propionate precursor for use as a feed ingredient to decrease CH4emissions from ruminants.
The expression of growth-arrest genes in the liver and kidney of the protein-restricted rat fetus
Authors: Maloney Christopher A. , Lilley Christina , Cruickshank Morven , McKinnon Caroline , Hay Susan M. , Rees William D.
Published: August 2005

During fetal life, there are periods of rapid cell proliferation, which are uniquely sensitive to nutritional perturbation. Feeding the pregnant rat a protein-restricted diet alters the growth trajectory of major fetal organs such as the kidney. By day 21 of gestation, the ratio of kidney weight to total body weight is reduced in the fetuses of dams fed a protein-deficient diet. In contrast, the ratio of fetal liver weight to total body weight is unchanged. To investigate the mechanisms underlying this disproportionate change in organ growth in the low-protein group, cell proliferation and differentiation have been assessed in the liver and kidney. The steady-state levels of mRNA for the growth-arrest and DNA-damage genegadd153/CHOP-10, CCAAT enhancer-binding proteins α and β were unaffected by maternal diet in both fetal liver and kidney. The mRNA for alpha-fetoprotein, albumin and hepatic glucokinase were unchanged in the liver, suggesting that maternal protein deficiency does not alter the state of differentiation. The steady-state levels of the mRNA coding for the cyclin-dependent protein kinase inhibitors (p15INK4a, p19INK4d, p21CIP1, p27KIP1and p57KIP2) were unchanged in the fetal livers but were significantly increased in the kidneys of fetuses from dams fed the low-protein diet. These results show that the asymmetrical growth of the kidney is associated with increases in mRNA for the Cip/Kip cyclin-dependent kinase inhibitors and that these may reflect specific lesions in organ development.
Comparison of methods to estimate non-milk extrinsic sugars and their application to sugars in the diet of young adolescents
Authors: Kelly Sarah A. M. , Summerbell Carolyn , Rugg-Gunn Andrew J. , Adamson Ashley , Fletcher Emma , Moynihan Paula J.
Published: August 2005

Consistent information on the non-milk extrinsic sugars (NMES) content of foods and the NMES intake by the population is required in order to allow comparisons between dietary surveys. A critical appraisal of methods of NMES estimation was conducted to investigate whether the different published methods for estimating the NMES content of foods lead to significantly different values for the dietary intake of NMES by children and to consider the relative practicality of each method. NMES values of foods were calculated using three different published descriptions of methods of NMES estimation, and the values were compared within food groups. Dietary intake values for English children aged 11–12 years were calculated using each method and compared in terms of overall NMES intake and the contribution of different food groups to NMES intake. There was no significant difference in the dietary intake of NMES in children between the method used in the National Diet and Nutrition Surveys (NDNS) (81·9 g/d; 95 % CI 79·0, 84·7) and a method developed by the Human Nutrition Research Centre (84·3 g/d; 95 % CI 81·4, 87·2) at Newcastle University, UK, although the latter gave slightly higher values. An earlier method used by the Ministry of Agriculture, Food and Fisheries gave significantly higher values than the other two methods (102·5 g/d; 95 % CI 99·3, 105·6;P<0·05). The method used in the NDNS surveys and the method used by the Human Nutrition Research Centre at Newcastle University are both thorough and detailed methods that give consistent results. However, the method used in the NDNS surveys was more straightforward to apply in practice and is the best method for a single uniform approach to the estimation of NMES.
The enhancing effects of a chicken-meat extract on serum Ig concentrations in normal and scalded animals
Authors: Chun Man Yan , Wai Yee Chung , Shing Wong Kwok , Pak Lai Tang , Ching Wan Koon , Kei Ko Kam
Published: August 2005

The aim of the study was to investigate the effects of a chicken-meat extract known as Essence of Chicken (EOC) on immune function in a normal and scalded animal model. In this experimental study, 120 rats were randomly allocated into three groups: a SHAM group (inflicted with a sham wound), a BURN group (inflicted with a full-thickness scald wound covering 30 % of total body surface area) and a CONTROL group. Rats in the SHAM and BURN groups were further divided into normal saline (NS)-fed and EOC-fed groups. They were fed by force-feeding with a feeding needle and blood samples were taken from each group on days 1, 8, 15 and 22 postburn. Serum IgG, IgA and IgM concentrations were determined by ELISA and the results of the EOC-fed and NS-fed cohorts of both the SHAM and BURN groups were compared. The level of significance was set atP<0·05. Serum IgG level of both SHAM-EOC and BURN-EOC cohorts showed significant elevation on day 8. IgA exhibited a significant increase in the SHAM-EOC group on day 15 and in the BURN-EOC group on day 22. A significant increase of IgM level was found on days 1 and 22 for the SHAM-EOC group and on day 15 for the BURN-EOC group. Conclusively, EOC was shown to have an enhancing effect on serum Ig levels for both normal and tissue-stressed rats. It is suggested that EOC may help improve immune function when the immune system is at normal status or when it faces a challenge.
Effect of starch on the cariogenic potential of sucrose
Authors: Ribeiro Cecilia C. C. , Tabchoury Cínthia P. M. , Del Bel Cury Altair A. , Tenuta Livia M. A. , Rosalen Pedro L. , Cury Jaime A.
Published: August 2005

Sincein vitroand animal studies suggest that the combination of starch with sucrose may be more cariogenic than sucrose alone, the study assessedin situthe effects of this association appliedin vitroon the acidogenicity, biochemical and microbiological composition of dental biofilm, as well as on enamel demineralization. During two phases of 14 d each, fifteen volunteers wore palatal appliances containing blocks of human deciduous enamel, which were extra-orally submitted to four groups of treatments: water (negative control, T1); 2 % starch (T2); 10 % sucrose (T3); and 2 % starch+10 % sucrose (T4). The solutions were dripped onto the blocks eight times per day. The biofilm formed on the blocks was analysed with regard to amylase activity, acidogenicity, and biochemical and microbiological composition. Demineralization was determined on enamel by cross-sectional microhardness. The greatest mineral loss was observed for the association starch+sucrose (P<0·05). Also, this association resulted in the highest lactobacillus count in the biofilm formed (P<0·05). In conclusion, the findings suggest that a small amount of added starch increases the cariogenic potential of sucrose.
Effects of disodium fumarate onin vitrorumen microbial growth, methane production and fermentation of diets differing in their forage:concentrate ratio
Authors: García-Martínez R. , Ranilla M. J. , Tejido M. L. , Carro M. D.
Published: August 2005

The effects of disodium fumarate on microbial growth, CH4production and fermentation of three diets differing in their forage content (800, 500 and 200 g/kg DM) by rumen micro-organismsin vitrowere studied using batch cultures. Rumen contents were collected from four Merino sheep. Disodium fumarate was added to the incubation bottles to achieve final concentrations of 0, 4 and 8 mm-fumarate, and15N was used as a microbial marker. Gas production was measured at regular intervals from 0 to 120 h of incubation. Fumarate did not affect (P>0·05) any of the measured gas production parameters. In 17 h incubations, the final pH and the production of acetate and propionate were increased linearly (P<0·001) by the addition of fumarate. Fumarate tended to increase (P=0·076) the organic matter disappearance of the diets and to decrease (P=0·079) the amount of NH3-N in the cultures. Adding fumarate to batch cultures tended (P=0·099) to decrease CH4production, the mean values of the decrease being 5·4 %, 2·9 % and 3·8 % for the high-, medium- and low-forage diet, respectively. Fumarate tended to increase (P=0·082) rumen microbial growth for the high-forage diet, but no differences (P>0·05) were observed for the other two diets. These results indicate that the effects of fumarate on rumen fermentation depend on the nature of the incubated substrate, the high-forage diet showing the greatest response.
Carbohydrate bioavailability
Authors: Englyst Klaus N. , Englyst Hans N.
Published: August 2005

There is consensus that carbohydrate foods, in the form of fruit, vegetables and whole-grain products, are beneficial to health. However, there are strong indications that highly processed, fibre-depleted, and consequently rapidly digestible, energy-dense carbohydrate food products can lead to over-consumption and obesity-related diseases. Greater attention needs to be given to carbohydrate bioavailability, which is determined by the chemical identity and physical form of food. The objective of the present concept article is to provide a rational basis for the nutritional characterisation of dietary carbohydrates. Based on the properties of carbohydrate foods identified to be of specific relevance to health, we propose a classification and measurement scheme that divides dietary carbohydrates into glycaemic carbohydrates (digested and absorbed in the small intestine) and non-glycaemic carbohydrates (enter the large intestine). The glycaemic carbohydrates are characterised by sugar type, and by the likely rate of digestion described by in vitro measurements for rapidly available glucose and slowly available glucose. The main type of non-glycaemic carbohydrates is the plant cell-wall NSP, which is a marker of the natural fibre-rich diet recognised as beneficial to health. Other non-glycaemic carbohydrates include resistant starch and the resistant short-chain carbohydrates (non-digestible oligosaccharides), which should be measured and researched in their own right. The proposed classification and measurement scheme is complementary to the dietary fibre and glycaemic index concepts in the promotion of healthy diets with low energy density required for combating obesity-related diseases.
Antioxidant status and risk of cancer in the SU.VI.MAX study: is the effect of supplementation dependent on baseline levels?
Authors: Galan Pilar , Briançon Serge , Favier Alain , Bertrais Sandrine , Preziosi Paul , Faure Henri , Arnaud Josiane , Arnault Nathalie , Czernichow Sébastien , Mennen Louise , Hercberg Serge
Published: August 2005

The SUpplementation en VItamines et Mineraux AntioXydants (SU.VI.MAX) study, a randomised double-blind, primary-prevention trial showed that after 7·5 years, low-dose antioxidant supplementation lowered the total cancer incidence in men, but not in women. To explain this difference in the impact of antioxidant supplementation in men and women, we hypothesised that the effect of supplementation is dependent on initial antioxidant status; 12 741 French adults (7713 females aged 35–60 years; 5028 males aged 45–60 years) received daily antioxidant supplementation (120 mg vitamin C, 30 mg vitamin E, 6 mg β-carotene, 100 μg Se, 20 mg Zn daily) or a matching placebo. Cut-off limits for baseline serum concentrations of the different antioxidant vitamins and minerals were defined as follows for both men and women: 0·3 μmol/l for β-carotene, 11·4 μmol/l for vitamin C, 15 μmol/l for vitamin E, 0·75 μmol/l for Se and 10·7 μmol/l for Zn. The percentage of men with serum concentrations under cut-off limits was higher for vitamins C and E and β-carotene in those who developed a cancer than in those who did not. The risk of cancer was higher in men with baseline concentrations of serum vitamin C or vitamin E under cut-off limits, but not in women. The effect of supplementation was greater in men with baseline serum concentrations of vitamin C, vitamin E and β-carotene below the cut-off limits compared with those above it. This effect was maintained only for vitamin E after adjustment for age, tobacco, and alcohol consumption and BMI. No effect of supplementation could be seen in women. Baseline antioxidant status is related to the risk of cancer in men but not in women and therefore does not entirely explain the differences observed in the effect of antioxidant supplementation on cancer risk between sexes in the SU.VI.MAX study.
The feeding route (enteral or parenteral) affects the plasma response of the dipetide Ala-Gln and the amino acids glutamine, citrulline and arginine, with the administration of Ala-Gln in preoperative patients
Authors: Melis Gerdien C. , Boelens Petra G. , van der Sijp Joost R. M. , Popovici Theodora , De Bandt Jean-Pascal , Cynober Luc , van Leeuwen Paul A. M.
Published: August 2005

Enhancement of depressed plasma concentrations of glutamine and arginine is associated with better clinical outcome. Supplementation of glutamine might be a way to provide the patient with glutamine, and also arginine, because glutamine provides the kidney with citrulline, from which the kidney produces arginine when plasma levels of arginine are low. The aim of the present study was to investigate the parenteral and enteral response of the administered dipeptide Ala-Gln, glutamine, citrulline and arginine. Therefore, seven patients received 20 g Ala-Gln, administered over 4 h, parenterally or enterally, on two separate occasions. Arterial blood samples were taken before and during the administration of Ala-Gln. ANOVA and a pairedttest were used to test differences (P<0·05). Ala-Gln was undetectable with enteral administration, whereas Ala-Gln remained stable at a plasma concentration of 268 μmol/l throughout parenteral infusion and rapidly decreased towards zero after infusion was stopped. The highest level of glutamine was observed with parenteral infusion of the dipeptide, although enteral infusion also significantly increased plasma levels of glutamine. The highest plasma response of citrulline was observed with the enteral administration of the dipeptide, although parenteral administration also increased plasma levels of citrulline. Plasma arginine increased significantly with parenteral infusion, but not with enteral administration of Ala-Gln. In conclusion, administrations of Ala-Gln, parenteral or enteral, resulted in an increased plasma glutamine response, as compared with baseline. Interestingly, in spite of the high availability of citrulline with enteral administration of the dipeptide, only parenteral infusion of Ala-Gln increased plasma arginine concentration.
Metabolisable energy consumption in the exclusively breast-fed infant aged 3–6 months from the developed world: a systematic review
Authors: Reilly John J. , Ashworth Susan , Wells Jonathan C. K.
Published: August 2005

The present study aimed to evaluate evidence on metabolisable energy consumption and pattern of consumption with age in infants in the developed world who were exclusively breast-fed, at around the time of introducing complementary feeding. We carried out a systematic review aimed at answering three questions: how much milk is transferred from mother to infant?; does transfer increase with the age of the infant?; and what is the metabolisable energy content of breast milk? Thirty-three eligible studies of 1041 mother–infant pairs reported transfer at 3–4 months of age, the weighted mean transfer being 779 (SD 40) g/d. Six studies (99 pairs) measured transfer at 5 months, with a weighted mean transfer of 827 (SD 39) g/d. Five studies (72 pairs) measured milk transfer at 6 months, reporting a weighted mean transfer of 894 (SD 87) g/d. Nine longitudinal studies reported no significant increases in milk transfer after 2–4 months. Twenty-five studies on breast-milk energy content were based on 777 mother–infant pairs. The weighted mean metabolisable energy content was 2·6 (SD 0·2) kJ/g. Breast-milk metabolisable energy content is probably lower, and breast-milk transfer slightly higher, than is usually assumed. Longitudinal studies do not support the hypothesis that breast-milk transfer increases markedly with age. More research on energy intake in 5–6-month-old exclusively breast-fed infants is necessary, and information on the metabolisability of breast milk in mid-infancy is desirable. This evidence should inform future recommendations on infant feeding and help to identify research needs in infant energy balance.
Bounds for the index of the centre in capable groups
Authors: Podoski K. , Szegedy B.
Published: August 2005

A group

H
H

is called capable if it is isomorphic to

G

/

Z

G/\mathbb {Z}

for some group

G
G

. Let

H
H

be a capable group. I. M. Isaacs (2001) showed that if

H
H

is finite, then the index of the centre is bounded above by some function of

|

H
′

|

|H’|

. We show that if

|

H
′

|

>
∞

|H’|>\infty

, then
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="StartAbsoluteValue upper H colon upper Z left-parenthesis upper H right-parenthesis EndAbsoluteValue less-than-or-equal-to StartAbsoluteValue upper H prime EndAbsoluteValue Superscript c log Super Subscript 2 Superscript StartAbsoluteValue upper H prime EndAbsoluteValue">

|

H
:
Z
(
H
)

|

≤

|

H
′

|

c

log
2

⁡

|

H
′

|

|H:Z(H)|\leq |H’|^{c\log _2|H’|}

with some constant

c
c

and this bound is essentially best possible. We complete a result of Isaacs, showing that if

H
′

H’

is a cyclic group, then

|

H
:

Z

(
H
)

|

≤

|

H
′

|

2

|H:\mathbf {Z}(H)|\leq |H’|^2

.
Examples of rational homotopy types of blow-ups
Authors: Lambrechts Pascal , Stanley Don
Published: August 2005

We give an example of two homotopic embeddings

j
0

,

j
1

:
V
↪
W

j_0,j_1\colon V\hookrightarrow W

of manifolds with isomorphic complex normal bundles but such that the blow-ups of

W
W

along

j
0

j_0

and along

j
1

j_1

have different rational homotopy types.
Morita equivalence for quantum Heisenberg manifolds
Authors: Abadie Beatriz
Published: August 2005

We discuss Morita equivalence within the family

{

D

μ
ν

c

:
c
∈

Z

,
 
c
>
0
,
 
μ
,
ν
∈

R

}

\{D_{\mu \nu }^c: c\in \mathbb {Z},\ c>0,\ \mu ,\nu \in \mathbb {R}\}

of quantum Heisenberg manifolds. Morita equivalence classes are described in terms of the parameters

μ
\mu

,

ν
\nu

and the rank of the free abelian group

G

μ
ν

=
2
μ

Z

+
2
ν

Z

+

Z

G_{\mu \nu }=2\mu \mathbb {Z}+2\nu \mathbb {Z}+\mathbb {Z}

associated to the

C
∗

C^*

-algebra

D

μ
ν

c

D_{\mu \nu }^{c}

.
Lorentz space extension of Strichartz estimates
Authors: Ahn Cheonghee , Cho Yonggeun
Published: August 2005

In this paper, Strichartz estimates for the solution of the Schrödinger evolution equation are considered on a mixed normed space with Lorentz norm with respect to the time variable.
Boundedness of operators on Hardy spaces via atomic decompositions
Authors: Bownik Marcin
Published: August 2005

An example of a linear functional defined on a dense subspace of the Hardy space

H
1

(

R

n

)

H^1(\mathbb {R}^n)

is constructed. It is shown that despite the fact that this functional is uniformly bounded on all atoms, it does not extend to a bounded functional on the whole

H
1

H^1

. Therefore, this shows that in general it is not enough to verify that an operator or a functional is bounded on atoms to conclude that it extends boundedly to the whole space. The construction is based on the fact due to Y. Meyer which states that quasi-norms corresponding to finite and infinite atomic decompositions in

H
p

H^p

,

0
>
p
≤
1

0>p \le 1

, are not equivalent.
Necessary conditions for Schatten class localization operators
Authors: Cordero Elena , Gröchenig Karlheinz
Published: August 2005

We study time-frequency localization operators of the form

A
a

φ
1

,

φ
2

A_a^{\varphi _1\!,\varphi _2}

, where

a
a

is the symbol of the operator and

φ
1

,

φ
2

\varphi _1 , \varphi _2

are the analysis and synthesis windows, respectively. It is shown in an earlier paper by the authors that a sufficient condition for

A
a

φ
1

,

φ
2

∈

S
p

(

L
2

(

R

d

)
)

A_a^{\varphi _1,\varphi _2}\in S_p(L^2(\mathbb {R}^d))

, the Schatten class of order

p
p

, is that

a
a

belongs to the modulation space

M

p
,
∞

(

R

2
d

)

M^{p,\infty }(\mathbb {R}^{2d})

and the window functions to the modulation space

M
1

M^1

. Here we prove a partial converse: if

A
a

φ
1

,

φ
2

∈

S
p

(

L
2

(

R

d

)
)

A_a^{\varphi _1,\varphi _2}\in S_p(L^2(\mathbb {R}^d))

for every pair of window functions

φ
1

,

φ
2

∈

S

(

R

2
d

)

\varphi _1,\varphi _2\in \mathcal {S}(\mathbb {R}^{2d})

with a uniform norm estimate, then the corresponding symbol

a
a

must belong to the modulation space

M

p
,
∞

(

R

2
d

)

M^{p,\infty }(\mathbb {R}^{2d})

. In this sense, modulation spaces are optimal for the study of localization operators. The main ingredients in our proofs are frame theory and Gabor frames. For

p
=
∞

p=\infty

and

p
=
2

p=2

, we recapture earlier results, which were obtained by different methods.
A new property of a class of Jacobi polynomials
Authors: Csordas George , Charalambides Marios , Waleffe Fabian
Published: August 2005

Polynomials whose coefficients are successive derivatives of a class of Jacobi polynomials evaluated at

x
=
1

x=1

are stable. This yields a novel and short proof of the known result that the Bessel polynomials are stable polynomials. Stability-preserving linear operators are discussed. The paper concludes with three open problems involving the distribution of zeros of polynomials.
On the construction of a class of bidimensional nonseparable compactly supported wavelets
Authors: Li Yun-Zhang
Published: August 2005

Chui and Wang discussed the construction of one-dimensional compactly supported wavelets under a general framework, and constructed one-dimensional compactly supported spline wavelets. In this paper, under a mild condition, the construction of

M
=
(

1

a
m
p
;
11

a
m
p
;
−
1

)

M=(\begin {smallmatrix} 1&11&-1\end {smallmatrix})

-wavelets is obtained.
Sharp van der Corput estimates and minimal divided differences
Authors: Rogers Keith
Published: August 2005

We find the sharp constant in a sublevel set estimate which arises in connection with van der Corput’s lemma. In order to do this, we find the nodes that minimise divided differences. We go on to find the sharp constant in the first instance of the van der Corput lemma. With these bounds we improve the constant in the general van der Corput lemma, so that it is asymptotically sharp.
A van der Corput lemma for the 𝑝-adic numbers
Authors: Rogers Keith
Published: August 2005

We prove a version of van der Corput’s lemma for polynomials over the

p
p

-adic numbers.
Symmetric stable processes in parabola–shaped regions
Authors: Bañuelos Rodrigo , Bogdan Krzysztof
Published: August 2005

We identify the critical exponent of integrability of the first exit time of the rotation invariant stable Lévy process from a parabola–shaped region.
On the predictability of discrete dynamical systems II
Authors: Bernardes Nilson
Published: August 2005

Given a metrizable compact topological

n
n

-manifold

X
X

with boundary and a metric

d
d

compatible with the topology of

X
X

, we prove that “most” continuous functions

f
:
X
→
X

f : X \to X

are non-sensitive at “most” points of

X
X

but are sensitive at every point of an infinite set which is dense in the set of all periodic points of

f
f

. We also establish some results concerning sets of periodic points and non-wandering points.
A note on asymptotically flat metrics on ℝ³ which are scalar-flat and admit minimal spheres
Authors: Corvino Justin
Published: August 2005

We use constructions by Miao and Chruściel-Delay to produce asymptotically flat metrics on

R

3

\mathbb {R}^3

which have zero scalar curvature and multiple stable minimal spheres. Such metrics are solutions of the time-symmetric vacuum constraint equations of general relativity, and in this context the horizons of black holes are stable minimal spheres. We also note that under pointwise sectional curvature bounds, asymptotically flat metrics of nonnegative scalar curvature and small mass do not admit minimal spheres, and hence are topologically

R

3

\mathbb {R}^3

.
Boundary and lens rigidity of finite quotients
Authors: Croke Christopher
Published: August 2005

We consider compact Riemannian manifolds

(
M
,
∂
M
,
g
)

(M,\partial M,g)

with boundary

∂
M

\partial M

and metric

g
g

on which a finite group

Γ
\Gamma

acts freely. We determine the extent to which certain rigidity properties of

(
M
,
∂
M
,
g
)

(M,\partial M,g)

descend to the quotient

(
M

/

Γ
,
∂

/

Γ
,
g
)

(M/\Gamma ,\partial /\Gamma ,g)

. In particular, we show by example that if

(
M
,
∂
M
,
g
)

(M,\partial M,g)

is boundary rigid, then

(
M

/

Γ
,
∂

/

Γ
,
g
)

(M/\Gamma ,\partial /\Gamma ,g)

need not be. On the other hand, lens rigidity of

(
M
,
∂
M
,
g
)

(M,\partial M,g)

does pass to the quotient.
Characteristic numbers of positively curved spin-manifolds with symmetry
Authors: Dessai Anand
Published: August 2005

Let

M
M

be a

S
p
i
n

Spin

-manifold of positive sectional curvature and dimension

>
8

>8

. Suppose a compact connected Lie group

G
G

acts smoothly on

M
M

. We show that the characteristic number

A
^

(
M
,
T
M
)

\hat A(M,TM)

vanishes if

G
G

contains two commuting involutions acting isometrically on

M
M

.
A remark on the homomorphism on 𝐶(𝑋)
Authors: Ercan Z. , Onal S.
Published: August 2005

Let

X
X

be a real compact space. Without using the axiom of choice we present a simple and direct proof that a non-zero homomorphism on

C
(
X
)

C(X)

is determined by a point.
Nonexistence of skew loops on ellipsoids
Authors: Ghomi Mohammad
Published: August 2005

We prove that every

C
1

C^1

closed curve immersed on an ellipsoid has a pair of parallel tangent lines. This establishes the optimal regularity for a phenomenon first observed by B. Segre. Our proof uses an approximation argument with the aid of an estimate for the size of loops in the tangential spherical image of a spherical curve.
Cyclic vectors in the Fock space over the complex plane
Authors: Izuchi Kou
Published: August 2005

In this paper, we characterize the cyclic vectors in the Fock space over the complex plane. We prove that a function

f
(
z
)

f(z)

is cyclic in the Fock space if and only if

f
(
z
)

f(z)

is a nonvanishing function in

L
a
2

(

C

)

L^2_a(\mathbb {C})

.
A simple proof of a curious congruence by Zhao
Authors: Ji Chun-Gang
Published: August 2005

The author gives a simple proof of the following curious congruence for odd prime

p
>
3

p>3

which was established by Jianqiang Zhao:
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="sigma-summation Underscript StartLayout 1st Row i plus j plus k equals p i comma j comma k greater-than 0 EndLayout Endscripts StartFraction 1 Over i j k EndFraction identical-to minus 2 upper B Subscript p minus 3 Baseline left-parenthesis mod p right-parenthesis period">

∑

i
+
j
+
k
=
p

i
,
 
j
,
 
k
>
0

1

i
j
k

≡
−
2

B

p
−
3

(
mod
 
p
)
.

\begin{equation*}\sum _{\substack {{i+j+k=p} {i,\ j,\ k>0}}}\frac {1}{ijk}\equiv -2B_{p-3}(\text {mod}\ p).\end{equation*}
Invariant subspaces for a class of complete Pick kernels
Authors: Jury Michael
Published: August 2005

Motivated by the work of McCullough and Trent, we investigate the

z
z

–invariant subspaces of the Hilbert function spaces associated to the Szegő kernels on the open unit disk. In particular, we characterize those kernels for which the the

z
z

–invariant subspaces are hyperinvariant, and (partially) those for which the so-called BLH subspaces are cyclic, obtaining counterexamples to two questions posed by McCullough and Trent.
(ℤ₂)^{𝕜}-actions with 𝕨(𝔽)=1
Authors: Lü Zhi
Published: August 2005

Suppose that

(
Φ
,

M
n

)

(\Phi , M^n)

is a smooth

(

Z

2

)
k

({\mathbb Z}_2)^k

-action on a closed smooth

n
n

-dimensional manifold such that all Stiefel-Whitney classes of the tangent bundle to each connected component of the fixed point set

F
F

vanish in positive dimension. This paper shows that if

dim
⁡

M
n

>

2
k

dim
⁡
F

\dim M^n>2^k\dim F

and each

p
p

-dimensional part

F
p

F^p

possesses the linear independence property, then

(
Φ
,

M
n

)

(\Phi , M^n)

bounds equivariantly, and in particular,

2
k

dim
⁡
F

2^k\dim F

is the best possible upper bound of

dim
⁡

M
n

\dim M^n

if

(
Φ
,

M
n

)

(\Phi , M^n)

is nonbounding.
Strong pseudo-contractions perturbed by compact operators in Banach spaces
Authors: Morales Claudio
Published: August 2005

Let

X
X

be a (real) Banach space, let

D
D

be an open subset of

X
X

, and let

B

(
X
)

\mathcal {B}(X)

denote the collection of all nonempty bounded and closed subsets of

X
X

. Suppose

T
T

is continuous from

D
¯

\overline {D}

into

B

(
X
)

\mathcal {B}(X)

with respect to the Hausdorff metric and strongly pseudo-contractive, while

g
g

is compact from

D
¯

\overline {D}

into

X
X

. Then

T
+
g

T+g

has a fixed point if it satisfies the classical Leray-Schauder condition on the boundary of

D
D

.
Open book decompositions for contact structures on Brieskorn manifolds
Authors: van Koert Otto , Niederkrüger Klaus
Published: August 2005

In this paper, we give an open book decomposition for the contact structures on some Brieskorn manifolds, in particular for the contact structures of Ustilovsky. The decomposition uses right-handed Dehn twists as conjectured by Giroux.
The Banach-Zarecki theorem for functions with values in metric spaces
Authors: Duda Jakub , Zajíček Luděk
Published: August 2005

Using an old result of Luzin about his property

(
N
)

(N)

, we prove a general version of the Banach-Zarecki theorem (on absolute continuity and Luzin’s property

(
N
)

(N)

).
On the maximal difference between an element and its inverse in residue rings
Authors: Ford Kevin , Khan Mizan , Shparlinski Igor , Yankov Christian
Published: August 2005

We investigate the distribution ofn−M(n)n - M(n)where\[<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper M left-parenthesis n right-parenthesis equals max left-brace StartAbsoluteValue a minus b EndAbsoluteValue colon 1 less-than-or-equal-to a comma b less-than-or-equal-to n minus 1 reverse-solidus and reverse-solidus a b identical-to 1 left-parenthesis mod n right-parenthesis right-brace period">M(n)=max{|a−b| : 1≤a,b≤n−1\ and\ ab≡1(modn)}.M(n)=\max \left \{ \, \left | a-b\right |\ :\ 1 \leq a,b\leq n-1 \textrm {\ and\ } ab \equiv 1\pmod n\right \}.\]Exponential sums provide a natural tool for obtaining upper bounds on this quantity. Here we use results about the distribution of integers with a divisor in a given interval to obtain lower bounds onn−M(n)n - M(n). We also present some heuristic arguments showing that these lower bounds are probably tight, and thus our technique can be a more appropriate tool to studyn−M(n)n - M(n)than a more traditional way using exponential sums.
Totally geodesic boundaries of knot complements
Authors: Kent Richard
Published: August 2005

Given a compact orientable

3
3

–manifold

M
M

whose boundary is a hyperbolic surface and a simple closed curve

C
C

in its boundary, every knot in

M
M

is homotopic to one whose complement admits a complete hyperbolic structure with totally geodesic boundary in which the geodesic representative of

C
C

is as small as you like.
Weak axioms of choice for metric spaces
Authors: Keremedis Kyriakos , Tachtsis Eleftherios
Published: August 2005

In the framework of ZF, i.e., Zermelo-Fraenkel set theory without the axiom of choice AC, we show that if the family of all non-empty, closed subsets of a metric space

(
X
,
d
)

(X,d)

has a choice function, then so does the family of all non-empty, open subsets of

X
X

. In addition, we establish that the converse is not provable in ZF. We also show that the statement “every subspace of the real line

R

\mathbb {R}

with the standard topology has a choice function for its family of all closed, non-empty subsets" is equivalent to the weak choice form “every continuum sized family of non-empty subsets of reals has a choice function".
Band limited functions on quantum graphs
Authors: Pesenson Isaac
Published: August 2005

The notion of band limited functions is introduced on a quantum graph. The main results of the paper are a uniqueness theorem and a reconstruction algorithm of such functions from discrete sets of values. It turns out that some of our band limited functions can have compact supports and their frequencies can be localized on the “time" side. It opens an opportunity to consider signals of a variable band width and to develop a sampling theory with variable rate of sampling.
On finite minimal non-nilpotent groups
Authors: Ballester-Bolinches A. , Esteban-Romero R. , Robinson Derek
Published: August 2005

Acritical groupfor a class of groupsX\mathfrak {X}is a minimal non-X\mathfrak {X}-group. The critical groups are determined for various classes of finite groups. As a consequence, a classification of the minimal non-nilpotent groups (also called Schmidt groups) is given, together with a complete proof of Gol’fand’s theorem on maximal Schmidt groups.
Geometric criteria for the nonexistence of cycles in Gause-type predator-prey systems
Authors: Liu Yaping
Published: August 2005

The global stability of a multi-species interacting system has apparently important biological implications. In this paper we study the global stability of Gause-type predator-prey models by providing new criteria for the nonexistence of cycles and limit cycles. Our criteria have clear geometrical interpretations and are easier to apply than other methods employed in recent studies. Using these criteria and related techniques we are able to develop new results on the existence and uniqueness of cycles in Gause-type models with various growth and response functions.
A noncommutative Szegö theorem for subdiagonal subalgebras of von Neumann algebras
Authors: Labuschagne L.
Published: August 2005

For almost forty years now the most frustrating open problem regarding the theory of finite maximal subdiagonal algebras has been the question regarding the universal validity of a non-commutative Szegö theorem and Jensen inequality (Arveson, 1967). These two properties are known to be equivalent. Despite extensive efforts by many authors, their validity has to date only been established in some very special cases. In the present note we solve the general problem in the affirmative by proving the universal validity of Szegö’s theorem for finite maximal subdiagonal algebras.
Strong laws for generalized absolute Lorenz curves when data are stationary and ergodic sequences
Authors: Helmers Roelof , Zitikis Ričardas
Published: August 2005

We consider generalized absolute Lorenz curves that include, as special cases, classical and generalized

L
L

-statistics as well as absolute or, in other words, generalized Lorenz curves. The curves are based on strictly stationary and ergodic sequences of random variables. Most of the previous results were obtained under the additional assumption that the sequences are weakly Bernoullian or, in other words, absolutely regular. We also argue that the latter assumption can be undesirable from the applications point of view.
The remainder in Weyl’s law for 𝑛-dimensional Heisenberg manifolds
Authors: Khosravi Mahta , Petridis Yiannis
Published: August 2005

We prove that the error term in Weyl’s law for ‘rational’(2n+1)(2n+1)-dimensional Heisenberg manifolds is of orderO(tn−7/41)O(t^{n-{7}/{41}}). In the ‘irrational’ case, for generic(2n+1)(2n+1)-dimensional Heisenberg manifolds withn>1n>1, we prove that the error term is of the orderO(tn−1/4log⁡t)O(t^{n-{1}/{4}}\log t). The polynomial growth is optimal.
Sampling expansions for functions having values in a Banach space
Authors: Han DeGuang , Zayed Ahmed
Published: August 2005

A sampling expansion for vector-valued functions having values in a Banach space, together with an inversion formula, is derived. The proof uses the concept of framing models of Banach spaces that generalizes the notion of frames in Hilbert spaces. Two examples illustrating the results are given, one involving functions having values in

L

p

[
−
π
,
π
]
,
1
>
p
≤
2

L^{p}[-\pi , \pi ], 1>p\leq 2

, and the second involving functions having values in

L

p

(

R

)

L^{p}(\mathbb {R})

for

1
>
p
>
∞
.

1 > p> \infty .
On the location of the discrete spectrum for complex Jacobi matrices
Authors: Egorova I. , Golinskii L.
Published: August 2005

We study spectrum inclusion regions for complex Jacobi matrices that are compact perturbations of the discrete Laplacian. The condition sufficient for the lack of a discrete spectrum for such matrices is given.
Quasi-e-locally cyclic torsion-free abelian groups
Authors: Dugas Manfred , Maxson C.
Published: August 2005

For a torsion-free abelian group

A
A

, we investigate the problem of determining when

E
n
d
(
A
)

End(A)

is maximal as a ring in the near-ring of all

0
0

-preserving functions on

A
A

. We introduce the concept of quasi-

E
n
d
(
A
)

End(A)

-locally cyclic groups and determine several properties of these abelian groups.