bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma etching and ashing: a technique for demonstrating internal structures of helminths using scanning electron microscopy
Authors: Veltkamp C.J. , Chubb J.C. 
Published: February 2006

AbstractPlasma etching and ashing for demonstrating the three-dimensional ultrastructure of the internal organs of helminths is described. Adult worms of the cestode Caryophyllaeides fennica were dehydrated through an ethanol series, critical point dried (Polaron E3000) and sputter coated with 60% gold-palladium (Polaron E5100) and glued to a standard scanning electron microscope (SEM) stub positioned as required for ashing. After initial SEM viewing of worm surfaces for orientation, stubs were placed individually in the reactor chamber of a PT7150 plasma etching and ashing machine. Worms were exposed to a radio frequency (RF) potential in a low pressure (0.2 mbar) oxygen atmosphere at room temperature. The oxidation process was controlled by varying the times of exposure to the RF potential between 2 to 30 min, depending on the depth of surface tissue to be removed to expose target organs or tissues. After each exposure the oxidized layer was blown from the surface with compressed air, the specimen sputter-coated, and viewed by SEM. The procedure was repeated as necessary, to progressively expose successive layers. Fine details of organs, cells within, and cell contents were revealed. Ashing has the advantage of providing three dimensional images of the arrangement of organs that are impossible to visualize by any other procedure, for example facilitating testes counts in cestodes. Both freshly-fixed and long-term stored helminths can be ashed. Ashing times to obtain the desired results were determined by trial so that some duplicate material was needed.
Changes in FaRP-like peptide levels during development of eggs from the plant-parasitic cyst nematode, Heterodera glycines
Authors: Masler E.P. 
Published: February 2006

AbstractThe plant-parasitic cyst nematode Heterodera glycines requires a host plant to complete its life cycle, which involves hatching of infective juveniles that parasitize through root entry. A laboratory population of H. glycines grown on soybean, Glycine max, undergoes a sharp increase in maturity between 5 and 6 weeks in culture, as measured by the proportion of eggs containing well developed pre-hatch juveniles (late development eggs) versus eggs without visible juveniles (early development eggs). The median percent of eggs classified as late development, representing all samples taken from 4 to 7 weeks in culture, was 61%. For all samples taken up to 5 weeks, 80% scored below the median. In samples taken after 5 weeks, 15% scored below the median. This shift in population maturity was accompanied by a significant increase (P < 0.01) in the number of hatched juveniles present in each sample. There was also a significant increase (P < 0.02) in amount of FaRP-like peptide detected by specific ELISA. Total FaRP levels increased from 0.18 ± 0.07 fMol FLRFamide equivalents per ng protein in early development eggs to 0.40 ± 0.17 in late development eggs. The level remained high in hatched juveniles. HPLC/ELISA detected as many as nine potential FaRPs in H. glycines, two of which were specifically increased (P < 0.005) in hatched juveniles. The association of FaRPs with maturing eggs and the possible involvement of these neuropeptides with juvenile hatching and motility are discussed.
Hermite and Hermite–Fejér interpolation for Stieltjes polynomials
Authors: Jung H. 
Published: February 2006

Let

w

λ

(
x
)
:=
(
1
−

x
2

)

λ
−
1

/

2

w_{\lambda }(x):=(1-x^2)^{\lambda -1/2}

and

P
n

(
λ
)

P_n^{(\lambda )}

be the ultraspherical polynomials with respect to

w

λ

(
x
)

w_{\lambda }(x)

. Then we denote by

E

n
+
1

(
λ
)

E_{n+1}^{(\lambda )}

the Stieltjes polynomials with respect to

w

λ

(
x
)

w_{\lambda }(x)

satisfying

∫

−
1

1

w

λ

(
x
)

P
n

(
λ
)

(
x
)

E

n
+
1

(
λ
)

(
x
)

x
m

d
x

{

=
0
,

a
m
p
;
0
≤
m
>
n
+
1
,

≠
0
,

a
m
p
;
m
=
n
+
1.

\begin{eqnarray*} \int _{-1}^1 w_{\lambda }(x) P_n^{(\lambda )}(x)E_{n+1}^{(\lambda )}(x) x^m dx \begin {cases} =0, & 0 \le m > n+1,\\ \neq 0, & m=n+1. \end{cases} \end{eqnarray*}

In this paper, we show uniform convergence of the Hermite–Fejér interpolation polynomials

H

n
+
1

[
⋅
]

H_{n+1}[\cdot ]

and

H

2
n
+
1

[
⋅
]

{\mathcal H}_{2n+1}[\cdot ]

based on the zeros of the Stieltjes polynomials

E

n
+
1

(
λ
)

E_{n+1}^{(\lambda )}

and the product

E

n
+
1

(
λ
)

P
n

(
λ
)

E_{n+1}^{(\lambda )}P_n^{(\lambda )}

for

0
≤
λ
≤
1

0 \le \lambda \le 1

and

0
≤
λ
≤
1

/

2

0 \le \lambda \le 1/2

, respectively. To prove these results, we prove that the Lebesgue constants of Hermite–Fejér interpolation operators for the Stieltjes polynomials

E

n
+
1

(
λ
)

E_{n+1}^{(\lambda )}

and the product

E

n
+
1

(
λ
)

P
n

(
λ
)

E_{n+1}^{(\lambda )}P_n^{(\lambda )}

are optimal, that is, the Lebesgue constants

‖

H

n
+
1

‖

∞

(
0
≤
λ
≤
1
)

\|H_{n+1}\|_{\infty }(0 \le \lambda \le 1)

and

‖

H

2
n
+
1

‖

∞

(
0
≤
λ
≤
1

/

2
)

\|{\mathcal H}_{2n+1}\|_{\infty } (0 \le \lambda \le 1/2)

have optimal order

O
(
1
)

O(1)

. In the case of the Hermite–Fejér interpolation polynomials

H

2
n
+
1

[
⋅
]

{\mathcal H}_{2n+1}[\cdot ]

for

1

/

2
>
λ
≤
1

1/2 > \lambda \le 1

, we prove weighted uniform convergence. Moreover, we give some convergence theorems of Hermite–Fejér and Hermite interpolation polynomials for

0
≤
λ
≤
1

0 \le \lambda \le 1

in weighted

L
p

L_p

norms.
New irrationality measures for 𝑞-logarithms
Authors: Matala-aho Tapani , Väänänen Keijo , Zudilin Wadim 
Published: February 2006

The three main methods used in diophantine analysis of

q
q

-series are combined to obtain new upper bounds for irrationality measures of the values of the

q
q

-logarithm function
\[

ln

q

⁡
(
1
−
z
)
=

∑

ν
=
1

∞

z

ν

q

ν

1
−

q

ν

,

|

z

|

⩽
1
,

\ln _{q}(1-z)=\sum _{\nu =1}^{\infty }\frac {z^{\nu }q^{\nu }}{1-q^{\nu }}, \qquad |z|\leqslant 1,

\]
when

p
=
1

/

q
∈

Z

∖
{
0
,
±
1
}

p=1/q\in \mathbb {Z}\setminus \{0,\pm 1\}

and

z
∈

Q

z\in \mathbb {Q}

.
General order multivariate Padé approximants for pseudo-multivariate functions
Authors: Cuyt Annie , Tan Jieqing , Zhou Ping 
Published: February 2006

Although general order multivariate Padé approximants were introduced some decades ago, very few explicit formulas for special functions have been given. We explicitly construct some general order multivariate Padé approximants to the class of so-called pseudo-multivariate functions, using the Padé approximants to their univariate versions. We also prove that the constructed approximants inherit the normality and consistency properties of their univariate relatives, which do not hold in general for multivariate Padé approximants. Examples include the multivariate forms of the exponential and the

q
q

-exponential functions
\[

E

(
x
,
y
)

=

∑

i
,
j
=
0

∞

x
i

y
j

(
i
+
j
)

!

E\left ( x,y\right ) =\sum _{i,j=0}^\infty \frac {x^iy^j}{\left ( i+j\right ) !}

\]
and
\[

E
q

(
x
,
y
)

=

∑

i
,
j
=
0

∞

x
i

y
j

[
i
+
j

]
q

!

,

E_q\left ( x,y\right ) =\sum _{i,j=0}^\infty \frac {x^iy^j}{[i+j]_q!},

\]
as well as the Appell function
\[

F
1

(
a
,
1
,
1
;
c
;
x
,
y
)

=

∑

i
,
j
=
0

∞

(
a
)

i
+
j

x
i

y
j

(
c
)

i
+
j

F_1\left ( a,1,1;c;x,y\right ) =\sum _{i,j=0}^\infty \frac {\left ( a\right ) _{i+j}x^iy^j}{\left ( c\right ) _{i+j}}

\]
and the multivariate form of the partial theta function
\[

F

(
x
,
y
)

=

∑

i
,
j
=
0

∞

q

−

(
i
+
j
)

2

/

2

x
i

y
j

.

F\left ( x,y\right ) =\sum _{i,j=0}^\infty q^{-\left ( i+j\right ) ^2/2}x^iy^j.

\]
Short‐term dehydroepiandrosterone treatment increases platelet cGMP production in elderly male subjects
Authors: Martina Valentino , Benso Andrea , Gigliardi Valentina Ramella , Masha Andi , Origlia Carla , Granata Riccarda , Ghigo Ezio 
Published: February 2006

SummaryObjective  Several clinical and population‐based studies suggest that dehydroepiandrosterone (DHEA) and its sulphate (DHEA‐S) play a protective role against atherosclerosis and coronary artery disease in human. However, the mechanisms underlying this action are still unknown. It has recently been suggested that DHEA‐S could delay atheroma formation through an increase in nitric oxide (NO) production.Study design and methods  Twenty‐four aged male subjects [age (mean ± SEM): 65·4 ± 0·7 year; range: 58·2–67·6 years] underwent a blinded placebo controlled study receiving DHEA (50 mg p.o. daily at bedtime) or placebo for 2 months. Platelet cyclic guanosine‐monophosphate (cGMP) concentration (as marker of NO production) and serum levels of DHEA‐S, DHEA, IGF‐I, insulin, glucose, oestradiol (E2), testosterone, plasminogen activator inhibitor (PAI)‐1 antigen (PAI‐1 Ag), homocysteine and lipid profile were evaluated before and after the 2‐month treatment with DHEA or placebo.Results  At the baseline, all variables in the two groups were overlapping. All parameters were unchanged after treatment with placebo. Conversely, treatment with DHEA (a) increased (P < 0·001 vs. baseline) platelet cGMP (111·9 ± 7·1 vs. 50·1 ± 4·1 fmol/106 plts), DHEA‐S (13·6 ± 0·8 vs. 3·0 ± 0·3 µmol/l), DHEA (23·6 ± 1·7 vs. 15·3 ± 1·4 nmol/l), testosterone (23·6 ± 1·0 vs. 17·7 ± 1·0 nmol/l) and E2 (72·0 ± 5·0 vs. 60·0 ± 4·0 pmol/l); and (b) decreased (P < 0·05 vs. baseline) PAI‐1 Ag (27·4 ± 3·8 vs. 21·5 ± 2·5 ng/ml) and low‐density lipoprotein (LDL) cholesterol (3·4 ± 0·2 vs. 3·0 ± 0·2 mmol/l). IGF‐I, insulin, glucose, triglycerides, total cholesterol, HDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB) and homocysteine levels were not modified by DHEA treatment.Conclusions  This study shows that short‐term treatment with DHEA increased platelet cGMP production, a marker of NO production, in healthy elderly subjects. This effect is coupled with a decrease in PAI‐1 and LDL cholesterol levels as well as an increase in testosterone and E2 levels. These findings, therefore, suggest that chronic DHEA supplementation would exert antiatherogenic effects, particularly in elderly subjects who display low circulating levels of this hormone.
Genetic and environmental determinants of circulating levels of angiogenin in community‐based sample
Authors: Pantsulaia Ia , Trofimov Svetlana , Kobyliansky Eugene , Livshits Gregory 
Published: February 2006

SummaryBackground  Measurement of angiogenin in plasma provides important prognostic and diagnostic information in variety of malignancies and may even correlate with cancer's progression. Nevertheless, nowadays, specific physiological mechanisms of this protein action as well as major factors regulating its circulating levels normally and in pathology are still poorly understood. The main objectives of this study were to examine the contribution of a number of endogenous factors, such as sex, age, body size and genetic effects on the production of angiogenin in apparently healthy individuals, and to assess the correlations in circulating levels between angiogenin and other molecules involved in angiogenesis.Methods  The plasma levels of angiogenin and each of the additional cytokines [interleukin‐6 (IL‐6), tumour necrosis factor‐α (TNF‐α), transforming growth factor‐β (TGF‐β), macrophage‐colony stimulating factor (M‐CSF), vascular endothelial growth factor (VEGF), epidermal growth factor (EGF), soluble intercellular adhesion molecule‐1 (sICAM)] were determined by enzyme‐linked immunoassay in a large family based sample.Results  Angiogenin levels were significantly higher in man than in women (360·64 104·04 ng/ml vs. 322·15 100·34 ng/ml, P < 0·01) and significantly correlated with age (P < 0·01) in both sexes. Genetic analysis showed that adjusted for potential covariates, 37·4 7·1% of angiogenin variation was attributable to putative genetic factors. The results of our study revealed that angiogenin concentrations were positively and significantly (P < 0·05) associated with sICAM, IL‐6, TNF‐α and M‐CSF levels in the female cohort.Conclusions  Our data provide reliable evidence for the substantial role of genetic factors in the determination of the phenotypic variability of angiogenin plasma levels. These findings of our study, including circulating angiogenin reference limits in healthy population and its correlation with angiogenic cytokines, may be of importance in determination of early stages of pathological angiogenesis.
Factors other than glucocorticoids are involved in the osteoblast activity decrease caused by tissue injury
Authors: Olmos J. M. , Amado J. A. , Valero C. , Hernández J. L. , González‐Macías J. 
Published: February 2006

SummaryObjective  Serum osteocalcin is a marker of bone formation. The concentration of osteocalcin is decreased with tissue injury. As glucocorticoids are known both to be increased in this situation and to diminish serum osteocalcin, we have hypothesized that they could be involved in this decrease.Design and patients  We compared osteocalcin levels in two groups of patients undergoing abdominal surgery, one receiving thiopental, and the other etomidate, a glucocorticoid synthesis blocker. For comparative reasons, another protein decreased by glucocorticoids (osteoprotegerin) was measured in patients anaesthetized with thiopental.Measurements  Serum osteocalcin, cortisol and albumin were determined before and over the 24 h following surgery. Serum concentration of osteoprotegerin (OPG) and receptor activator of the nuclear factor κB ligand (RANKL) were also determined before and 24 h after surgery in a third group of nine patients who received thiopental for anaesthetic induction.Results  Cortisol levels were increased in the thiopental group, whereas, as expected, were decreased in etomidate patients. However, serum osteocalcin concentration decreased in a similar way in both groups. Serum OPG and RANKL levels were within the normal range at baseline and did not significantly change after surgery.Conclusions  The decrease in serum osteocalcin induced by tissue injury is independent of the increase in cortisol secretion triggered by the latter. In addition, another pharmacologically proven effect of cortisol on bone metabolism, OPG inhibition, could not be demonstrated in the first 24 h following surgery, in spite of the physiological increase in endogenous cortisol secretion taking place in this period.
Parafibromin mutations in hereditary hyperparathyroidism syndromes and parathyroid tumours
Authors: Bradley K. J. , Cavaco B. M. , Bowl M. R. , Harding B. , Cranston T. , Fratter C. , Besser G. M. , da Conceição Pereira M. , Davie M. W. J. , Dudley N. , Leite V. , Sadler G. P. , Seller A. , Thakker R. V. 
Published: February 2006

SummaryObjective  To investigate two patients with the hyperparathyroidism‐jaw tumour (HPT‐JT) syndrome and three patients with familial isolated hyperparathyroidism (FIHP), together with 31 parathyroid tumours (2 HPT‐JT, 2 FIHP and 27 sporadic) for HRPT2 mutations. The HPT‐JT syndrome and FIHP are autosomal dominant disorders that may be caused by abnormalities of the HRPT2 gene, located on chromosome 1q31.2. HRPT2 encodes a 531 amino acid protein, parafibromin, which interacts with human homologues of the yeast Paf1 complex.Design  Leukocyte and tumor DNA was used with HRPT2‐specific primers for polymerase chain reaction amplification of the 17 exons and their splice junctions, and the DNA sequences of the polymerase chain reaction products determined.Results  Three heterozygous germline HRPT2 mutations, two in HPT‐JT and one in FIHP patients, were identified. These consisted of one 1‐bp duplication (745dup1bp), 1 nonsense (Arg234Stop) and 1 missense (Asp379Asn) mutation. One parathyroid tumour from an FIHP patient was demonstrated to harbour a germline deletion of 1 bp together with a somatic missense (Leu95Pro) mutation, consistent with a ‘two‐hit’ model for hereditary cancer. The 27 sporadic benign parathyroid tumours did not harbour any HRPT2 somatic mutations. Six HRPT2 polymorphisms with allele frequencies ranging from 2% to 15% were detected.Conclusions  Our results have identified three novel HRPT2 mutations (two germline and one somatic). The Asp379Asn mutation is likely to disrupt interaction with the human homologue of the yeast Paf1 complex, and the demonstration of combined germline and somatic HRPT2 mutations in a parathyroid tumour provide further evidence for the tumour suppressor role of the HRPT2 gene.
Associations between liver histology and cortisol secretion in subjects with nonalcoholic fatty liver disease
Authors: Targher Giovanni , Bertolini Lorenzo , Rodella Stefano , Zoppini Giacomo , Zenari Luciano , Falezza Giancarlo 
Published: February 2006

SummaryObjectives  To assess associations between the activity of hypothalamo‐pituitary‐adrenal (HPA) axis and liver histology in patients with nonalcoholic fatty liver disease (NAFLD).Design and patients  In a cross‐sectional study, we enrolled 50 consecutive, overweight, NAFLD patients and 40 control subjects who were comparable for age, sex and body mass index (BMI).Measurements  NAFLD (by liver biopsy), HPA axis activity (by 24‐hour urinary free cortisol [UFC] excretion and serum cortisol levels after 1 mg dexamethasone), insulin resistance (by homeostasis model assessment: HOMA‐IR), and metabolic syndrome (MetS) features.Results  NAFLD patients had markedly higher (P < 0·001) 24‐h UFC (149 ± 24 vs. 90 ± 16 nmol/day) and postdex suppression cortisol concentrations (32 ± 10 vs. 16 ± 7 nmol/l) than controls. The MetS and its individual components were more frequent among NAFLD patients. The marked differences in urinary/serum cortisol concentrations that were observed between the groups were little affected by adjustment for age, sex, BMI, waist circumference, systolic blood pressure, triglycerides, homeostasis model assessment for insulin resistance score and presence of diabetes. Importantly, 24‐h UFC and postdex cortisol concentrations strongly correlated to hepatic necroinflammatory grade (P < 0·01) and fibrosis stage (P < 0·001) among NAFLD patients. By logistic regression analysis, 24‐h UFC (odds ratio (OR) 1·80, 95%CI 1·3–2·8) or postdex cortisol concentrations (OR 1·95, 95%CI 1·4–3·1) independently predicted the severity of hepatic fibrosis, but not necroinflammation, after adjustment for potential confounders.Conclusions  These results suggest that NAFLD patients have a subtle, chronic overactivity in the HPA axis (that is closely associated with the severity of liver histopathology) leading to subclinical hypercortisolism that might be implicated in the development of NAFLD.
Sorption of phosphorus in field‐moist and air‐dried samples from four weakly developed cultivated soil profiles
Authors: Peltovuori T. 
Published: February 2006

SummarySorption of phosphorus (P) in complete soil profiles in northern Europe is not adequately documented. I measured the sorption in genetic horizons of four cultivated soils (Inceptisols, Spodosol) in Finland using both field‐moist and air‐dried soil samples, fitted modified Freundlich equations (Q = a × Ib − q) to the data, and presented the results in quantity/intensity (Q/I) graphs. Least‐squares‐estimates for the parameters of the modified Freundlich equation (a, b, q) were found to be imprecise measures of sorption. Values derived from the fitted equations (the amount of P sorbed at the P concentration of 2 mg litre−1 and P buffering capacity at the same concentration) were more precise. Both were correlated with concentrations of oxalate‐extractable iron and aluminium. In all soils, there was a distinct difference in sorption between the fertilized Ap horizons and the subsurface horizons, which retained P strongly. Most of the sorption capacity was located in the B horizons at depths between 0.3 and 0.7 m. The results demonstrate the effects of soil‐forming processes and human impact on the sorption of P in the soils. Drying the samples prior to the sorption experiments altered the shape of the Q/I graphs. It increased dissolution of P at small P concentrations, sorption at large P concentrations, and the estimates for P buffering capacity. The effects of drying soil samples on the results and the imprecision of the parameters estimated with the modified Freundlich equation should be taken into account when interpreting results of Q/I experiments.
The relationship between yellowhammer breeding performance, arthropod abundance and insecticide applications on arable farmland
Authors: HART J. D. , MILSOM T. P. , FISHER G. , WILKINS V. , MOREBY S. J. , MURRAY A. W. A. , ROBERTSON P. A. 
Published: February 2006

Summary

The UK population of yellowhammers has declined since the mid‐1980s. Concurrent increases in the use of pesticides are believed to have reduced the availability of food resources for farmland birds, including yellowhammers. To mitigate the consequences of insecticide applications on yellowhammer productivity, the relationships between insecticide application, arthropod food abundance and breeding success require quantification.
We studied nesting yellowhammers on a lowland arable farm in North Yorkshire between 2001 and 2003, to examine the effects of food abundance on breeding success and the effects of insecticide on food abundance. Arthropod abundances around individual nests were sampled and the timing and location of insecticide applications were recorded.
Nestling condition and mass on day 6 after hatching were positively correlated with the abundance of arthropods important in the diet of nestling yellowhammers. Greater mean body mass and condition corresponded with a lower incidence of brood reduction.
The abundance of arthropods important in the diet of nestling yellowhammers increased between mid‐May and the end of July. However, arthropod samples collected within 20 days of an insecticide application did not show this seasonal increase in abundance and were depressed at levels likely to affect yellowhammer breeding performance adversely.
Synthesis and applications. We have demonstrated how insecticide applications can depress yellowhammer breeding productivity. We provide the requisite data for a framework that enables predictions to be made about the probable population effects of particular pesticide products. If the risk of indirect effects can be predicted accurately then appropriate mitigation and compensation measures could be incorporated into pesticide regulatory procedures and/or agri‐environment schemes.
Stress trajectories in mothers of young children with Down syndrome
Authors: Most D. E. , Fidler D. J. , Laforce‐Booth C. , Kelly J. 
Published: February 2006

AbstractBackground  In this study, we investigated the early development of stress in mothers of children with Down syndrome, compared with mothers of children with developmental disabilities of mixed aetiologies. Growth modelling analyses were used to explore: (1) whether mothers of children with Down syndrome demonstrated distinct patterns of stress during their children’s early development, compared with mothers of children with other developmental disabilities; and (2) whether there was a relation between child behavioural characteristics and the level and rate of change in stress observed in each population.Method  The stress trajectories of mothers of young children with Down syndrome (n = 25) and a mixed‐aetiology comparison group (n = 49) were estimated, using growth modelling on data collected at ages of 15, 30 and 45 months.Results  On average, stress in the mixed comparison group was higher at Time 1 and remained unchanged over time, while stress in the Down syndrome group was lower at Time 1 but increased steadily. After taking diagnostic group membership into account, more advanced cognitive‐linguistic functioning and lower levels of maladaptive behaviours at all time points were associated with lower levels of maternal stress.Conclusions  These findings suggest that the cognitive‐linguistic and behavioural trajectory observed in early development in Down syndrome may contribute to the changes in maternal stress levels observed throughout these early years. Implications for developing targeted and time‐ sensitive family interventions for families of children with Down syndrome are discussed.