bluuebunny/crossref_metadata_2025_split huggingface dataset:
Splitting of quartic polynomials
Authors: Adams William W. 
Published: June 2010

For integers r, s, t, u define the recursion

A
(
n
+
4
)
=
r
A
(
n
+
3
)
−
s
A
(
n
+
2
)
+
t
A
(
n
+
1
)
−
u
A
(
n
)

A(n + 4) = rA(n + 3) - sA(n + 2) + tA(n + 1) - uA(n)

where the initial conditions are set up in such a way that

A
(
n
)
=

α
n

+

β
n

+

γ
n

+

δ
n

A(n) = {\alpha ^n} + {\beta ^n} + {\gamma ^n} + {\delta ^n}

where

α
,
β
,
γ
,
δ

\alpha ,\beta ,\gamma ,\delta

are the roots of the associated polynomial

f
(
x
)
=

x
4

−
r

x
3

+
s

x
2

−
t
x
+
u

f(x) = {x^4} - r{x^3} + s{x^2} - tx + u

In this paper a detailed deterministic procedure using the

A
(
n
)

A(n)

for finding how

f
(
x
)

f(x)

splits modulo a prime integer p is given. This gives for p not dividing the discriminant of

f
(
x
)

f(x)

the splitting of p in the field obtained by adjoining a root of

f
(
x
)

f(x)

to the rational numbers. There is an interesting connection between the results here for reciprocal polynomials and some work of D. Shanks.
Gaussian quadrature involving Einstein and Fermi functions with an application to summation of series
Authors: Gautschi Walter , Milovanović Gradimir V. 
Published: June 2010

Polynomials

π
k

(
⋅
)
=

π
k

(
⋅
;
d
λ
)

{\pi _k}( \cdot ) = {\pi _k}( \cdot ;d\lambda )

,

k
=
0
,
1
,
2
,
…

k = 0,1,2, \ldots

, are constructed which are orthogonal with respect to the weight distributions

d
λ
(
t
)
=

(
t

/

(

e
t

−
1
)

)
r

d
t

d\lambda (t) = {(t/({e^t} - 1))^r}\;dt

and

d
λ
(
t
)
=

(
1

/

(

e
t

+
1
)

)
r

d
t

d\lambda (t) = {(1/({e^t} + 1))^r}\;dt

,

r
=
1
,
2

r = 1,2

, on

(
0
,
∞
)

(0,\infty )

. Moment-related methods being inadequate, a discretized Stieltjes procedure is used to generate the coefficients

α
k

,

β
k

{\alpha _k},{\beta _k}

in the recursion formula

π

k
+
1

(
t
)
=
(
t
−

α
k

)

π
k

(
t
)
−

β
k

π

k
−
1

(
t
)

{\pi _{k + 1}}(t) = (t - {\alpha _k}){\pi _k}(t) - {\beta _k}{\pi _{k - 1}}(t)

,

k
=
0
,
1
,
2
,
…

k = 0,1,2, \ldots

,

π
0

(
t
)
=
1

{\pi _0}(t) = 1

,

π

−
1

(
t
)
=
0

{\pi _{ - 1}}(t) = 0

. The discretization is effected by the Gauss-Laguerre and a composite Fejér quadrature rule, respectively. Numerical values of

α
k

,

β
k

{\alpha _k},{\beta _k}

, as well as associated error constants, are provided for

0
⩽
k
⩽
39

0 \leqslant k \leqslant 39

. These allow the construction of Gaussian quadrature formulae, including error terms, with up to 40 points. Examples of n-point formulae,

n
=
5
(
5
)
40

n = 5(5)40

, are provided in the supplements section at the end of this issue. Such quadrature formulae may prove useful in solid state physics calculations and can also be applied to sum slowly convergent series.
Computing an arithmetic constant related to the ring of Gaussian integers
Authors: Gramain F. , Weber M. 
Published: June 2010

We compute the analogue for

Z

[
i
]

{\mathbf {Z}}[i]

of Euler’s constant, that is

δ
=

lim

n
→
+
∞

δ
n

\delta = {\lim _{n \to + \infty }}{\delta _n}

, where

δ
n

=
(

Σ

2
⩽
k
⩽
n

1

/

π

r
k
2

)
−
log
⁡
n

{\delta _n} = ({\Sigma _{2 \leqslant k \leqslant n}}1/\pi r_k^2) - \log n

. For this purpose we give an estimate for
\[

r
k

=
min

{

r
⩾
0
;

there exists

z
∈

C

such that card

(

Z

[
i
]
∩

D
¯

(
z
,
r
)
)
⩾
k

}

,

{r_k} = \min \left \{ {r \geqslant 0;{\text {there exists}}\;z \in {\mathbf {C}}\;{\text {such that card}}({\mathbf {Z}}[i] \cap \bar D(z,r)) \geqslant k} \right \},

\]
and we compute a great number of values of

r
k

{r_k}

.
Least squares approximation with constraints
Authors: Milovanović Gradimir V. , Wrigge Staffan 
Published: June 2010

In this paper we study two families of functions

F
e

{F_e}

and

F
o

{F_o}

, and show how to approximate the functions in the interval

[
−
1
,
1
]

[ - 1,1]

. The functions are assumed to be real when the argument is real. We define
\[

F
e

=
{
f
:
f
(
−
x
)
=
f
(
x
)
,
f
(
1
)
=
0
,
f
∈

L
2

[
−
1
,
1
]
}

{F_e} = \{ f:f( - x) = f(x),f(1) = 0,f \in {L^2}[ - 1,1]\}

\]
and
\[

F
o

=
{
f
:
f
(
−
x
)
=
−
f
(
x
)
,
f
(
1
)
=
0
,
f
∈

L
2

[
−
1
,
1
]
}
.

{F_o} = \{ f:f( - x) = - f(x),f(1) = 0,f \in {L^2}[ - 1,1]\} .

\]
Let further

P

m

{\mathcal {P}_m}

be the set of all real polynomials of degree not higher than m such that the polynomials belong to the set

F
e

{F_e}

if m is even and to the set

F
o

{F_o}

if m is odd. We determine the least squares approximation for the function

f
∈

F
e

f \in {F_e}

(or

F
o

{F_o}

) in the class

P

2
n

{\mathcal {P}_{2n}}

(or

P

2
n
+
1

{\mathcal {P}_{2n + 1}}

), with respect to the norm

‖
f
‖

=

(
(
f
,
f
)

)

1

/

2

\left \| f \right \| = {((f,f))^{1/2}}

, where the inner product is defined by

(
f
,
g
)
=

∫

−
1

1

f
(
x
)
g
(
x
)
w
(
x
)
d
x

(f,g) = \smallint _{ - 1}^1f(x)g(x)w(x)dx

, with

f
,
g
∈

L
2

[
−
1
,
1
]
=

L
w
2

[
−
1
,
1
]

f,g \in {L^2}[ - 1,1] = L_w^2[ - 1,1]

and

w
(
x
)
=

(
1
−

x
2

)

λ
−
1

/

2

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

. We also consider the general case when f is neither an even nor an odd function but

f
∈

L
2

[
−
1
,
1
]

f \in {L^2}[ - 1,1]

and

f
(
−
1
)
=
f
(
1
)
=
0

f( - 1) = f(1) = 0

. Using the theory of Gegenbauer polynomials we obtain the approximating polynomials in the form
\[

ϕ

2
n

(
x
)
=

∑

k
=
1

n

d

n
,
k

(
1
−

x
2

)

k

when

f
∈

F
e

{\phi _{2n}}(x) = \sum \limits _{k = 1}^n {{d_{n,k}}{{(1 - {x^2})}^k}\;{\text {when}}\,f \in {F_e}}

\]
and
\[

ϕ

2
n
+
1

(
x
)
=
x

∑

k
=
1

n

e

n
,
k

(
1
−

x
2

)

k

when

f
∈

F
o

.

{\phi _{2n + 1}}(x) = x\sum \limits _{k = 1}^n {{e_{n,k}}{{(1 - {x^2})}^k}\;{\text {when}}\,f \in {F_o}.}

\]
We apply the general theory to the functions

f
(
x
)
=
cos
⁡
(
π
x

/

2
)

f(x) = \cos (\pi x/2)

and

f
(
x
)
=

J
0

(

a
0

x
)

f(x) = {J_0}({a_0}x)

, where

a
0

=
{
min
x
>
0
:

J
0

(
x
)
=
0
}

{a_0} = \{ \min x > 0:{J_0}(x) = 0\}

.
Rate of convergence of Shepard’s global interpolation formula
Authors: Farwig Reinhard 
Published: June 2010

Given any data points

x
1

,
…
,

x
n

{x_1}, \ldots ,{x_n}

in

R

s

{{\mathbf {R}}^s}

and values

S
p
q

S_p^q

of a function f, Shepard’s global interpolation formula reads as follows:
\[

S
p
0

f
(
x
)
=

∑
i

f
(

x
i

)

w
i

(
x
)
,

w
i

(
x
)
=

|

x
−

x
i

|

−
p

/

∑
j

|

x
−

x
j

|

−
p

,

S_p^0f(x) = \sum \limits _i {f({x_i}){w_i}(x),\quad {w_i}(x) = |x - {x_i}{|^{ - p}}/\sum \limits _j {|x - {x_j}{|^{ - p}},} }

\]
where

f
(

x
1

)
,
…
,
f
(

x
n

)

f({x_1}), \ldots ,f({x_n})

denotes the Euclidean norm in

|

⋅

|

| \cdot |

. This interpolation scheme is stable, but if

R

s

{{\mathbf {R}}^s}

, the gradient of the interpolating function vanishes in all data points. The interpolation operator

p
>
1

p > 1

is defined by replacing the values

S
p
q

S_p^q

in

f
(

x
i

)

f({x_i})

by Taylor polynomials of f of degree

S
p
0

f

S_p^0f

. In this paper, we investigate the approximating power of

q
∈

N

q \in {\mathbf {N}}

for all values of p, q and s.
Integral equations on the half-line: a modified finite-section approximation
Authors: Sloan I. H. , Spence A. 
Published: June 2010

We consider the approximate solution of integral equations of the form

y
(
t
)
−

∫
0
∞

k
(
t
,
s
)
y
(
s
)

d
s
=
f
(
t
)

y(t) - \smallint _0^\infty k(t,s) y(s)\,ds = f(t)

, where the conditions on

k
(
t
,
s
)

k(t,s)

are such that kernels of the Wiener-Hopf form

k
(
t
,
s
)
=
κ
(
t
−
s
)

k(t,s) = \kappa (t - s)

are included in the analysis. The finite-section approximation, in which the infinite integral is replaced by

∫
0
β

\smallint _0^\beta

for some

β
>
0

\beta > 0

, yields an approximate solution

y
β

(
t
)

{y_\beta }(t)

that is known, under very general conditions, to converge to

y
(
t
)

y(t)

as

β
→
∞

\beta \to \infty

with t fixed. However, the convergence is uniform only on finite intervals, and the approximation is typically very poor for

t
>
β

t > \beta

. Under the assumption that f has a limit at infinity, we here introduce a modified finite-section approximation with improved approximation properties, and prove that the new approximate solution converges uniformly to y as

β
→
∞

\beta \to \infty

. A numerical example illustrates the improvement.
Some properties of rank-2 lattice rules
Authors: Lyness J. N. , Sloan I. H. 
Published: June 2010

A rank-2 lattice rule is a quadrature rule for the (unit) s-dimensional hypercube, of the form
\[

Q
f
=
(
1

/

n
1

n
2

)

∑

j
1

=
1

n
1

∑

j
2

=
1

n
2

f
¯

(

j
1

z

1

/

n
1

+

j
2

z

2

/

n
2

)
,

Qf = (1/{n_1}{n_2})\sum \limits _{{j_1} = 1}^{{n_1}} {\sum \limits _{{j_2} = 1}^{{n_2}} {\bar f({j_1}{{\mathbf {z}}_1}/{n_1} + {j_2}{{\mathbf {z}}_2}/{n_2}),} }

\]
which cannot be re-expressed in an analogous form with a single sum. Here

f
¯

\bar f

is a periodic extension of f, and

z

1

{{\mathbf {z}}_1}

,

z

2

{{\mathbf {z}}_2}

are integer vectors. In this paper we discuss these rules in detail; in particular, we categorize a special subclass, whose leading one- and two-dimensional projections contain the maximum feasible number of abscissas. We show that rules of this subclass can be expressed uniquely in a simple tricycle form.
Activation of liver X receptors with T0901317 attenuates cardiac hypertrophy in vivo
Authors: Kuipers Irma , Li Jiang , Vreeswijk‐Baudoin Inge , Koster Johan , van der Harst Pim , Silljé Herman H.W. , Kuipers Folkert , van Veldhuisen Dirk J. , van Gilst Wiek H. , de Boer Rudolf A. 
Published: June 2010

AimsLiver X receptor (LXR) is a nuclear receptor regulating cholesterol metabolism. Liver X receptor has also been shown to exert anti‐proliferative and anti‐inflammatory properties. In this study, we evaluated the effect of LXR activation on cardiac hypertrophy in vitro and in vivo.Methods and resultsTreatment with the synthetic LXR agonist T0901317 (T09) attenuated the hypertrophic response of cultured cardiomyocytes to endothelin‐1 almost to control levels. siRNA interference showed that this effect was indeed LXR specific. To corroborate these findings in vivo, abdominal aortic constriction (AC) was used as a pressure overload model to induce cardiac hypertrophy in wild‐type and LXR‐α‐deficient (LXR‐α−/−) mice. In wild‐type mice, T09 treatment resulted in a decrease of cardiac wall thickening 4 and 7 weeks after AC. Also, after 7 weeks of AC, mean arterial blood pressure and left ventricular weight/body weight (LVW/BW) ratios were decreased in T09 treated mice. These effects were not observed in LXR‐α−/− mice, indicating that the beneficial effect of LXR activation on cardiac hypertrophy is attributable to the LXR‐α isoform. T09 induced robust cardiac expression of metabolic genes which are downstream of LXR‐α, such as SREBP‐1c, ABCA1, and ABCG1.ConclusionTogether these results indicate that LXR exerts salutary effects in cardiac hypertrophy, possibly via metabolic remodelling.
The association between a deep-sea gastropod Pedicularia sicula (Caenogastropoda: Pediculariidae) and its coral host Errina dabneyi (Hydrozoa: Stylasteridae) in the Azores
Authors: Braga-Henriques Andreia , Carreiro-Silva Marina , Porteiro Filipe M. , de Matos Valentina , Sampaio Íris , Ocaña Oscar , Ávila Sérgio P. 
Published: June 2010

Abstract
Braga-Henriques, A., Carreiro-Silva, M., Porteiro, F. M., de Matos, V., Sampaio, Í., Ocaña, O., and Ávila, S., P. 2011. The association between a deep-sea gastropod Pedicularia sicula (Caenogastropoda: Pediculariidae) and its coral host Errina dabneyi (Hydrozoa: Stylasteridae) in the Azores. – ICES Journal of Marine Science, 68: 399–407. The Azores region harbours the richest communities of stylasterid corals in the Northeast Atlantic area. Of the nine deep-water species found there, Errina dabneyi seems to be the most abundant species; it is commonly collected as bycatch from longline fishing. E. dabneyi host Pedicularia gastropods on their branches, and a detailed study of shell shape and morphometry at different growth stages, complemented by shell characterization through scanning electron microscopy, allows the individuals to be identified as Pedicularia sicula. The incidence of this species on E. dabneyi was high (69.8%), with abundances ranging between 1 and 223 individuals per colony. The pediculariids exhibited a high degree of plasticity and produced evident traces on the stylasterid skeletons at their fixation points, suggesting that they are ectoparasites and not predators of E. dabneyi. The stylasterid colonies also hosted a rich associated fauna dominated by suspension-feeders using the coral as substratum and for protection.
Brachioradial pruritus successfully treated with gabapentin
Authors: YILMAZ Sadik , CEYHAN Ali Murat , BAYSAL AKKAYA Vahide 
Published: June 2010

AbstractBrachioradial pruritus (BRP) is a mysterious entity characterized by localized pruritus of the dorsolateral aspect of the arm. The precise etiology of BRP remains unknown, but sun exposure and/or cervical spine lesions seem to be triggering or at least aggravating factors. Many treatment alternatives including non‐steroidal anti‐inflammatory drugs, topical capsaicin, topical corticosteroids, photoprotection, carbamazepine and acupuncture have been used with different success rates. Recently, gabapentin, an antiepileptic agent, has been reported to be an effective therapeutic agent in BRP. Herein, we report a 64‐year‐old man with BRP who showed good response to gabapentin therapy.
Necrotizing fasciitis caused by Staphylococcus epidermidis in a neonate with extremely low birthweight
Authors: PEKER Erdal , KIRIMI Ercan , TUNCER Oguz , CEYLAN Abdullah , CAGAN Eren , DOGAN Murat 
Published: June 2010

AbstractNecrotizing fasciitis (NF) is a severe life‐threatening soft tissue infection characterized by rapidly spreading necrosis of the fascia and the subcutaneous tissue. The initial skin presentation ranges from minimal rash to cellulites. The lesions subsequently spread rapidly. Even with appropriate medical and surgical therapy, the mortality rate in NF is more than 50%. In cases of neonates, mortality rate is higher than that ratio. High index of suspicion, prompt aggressive surgery, appropriate antibiotics and supportive care are the mainstays of management in the newborn infant with NF. Herein, we report a case of invasive and mortal NF caused by Staphylococcus epidermidis in an infant with extremely low birthweight.
MEK/ERK and p38 MAPK regulate chondrogenesis of rat bone marrow mesenchymal stem cells through delicate interaction with TGF‐β1/Smads pathway
Authors: Li J. , Zhao Z. , Liu J. , Huang N. , Long D. , Wang J. , Li X. , Liu Y. 
Published: June 2010

AbstractObjectives:  This study was carried out to reveal functions and mechanisms of MEK/ERK and p38 pathways in chondrogenesis of rat bone marrow mesenchymal stem cells (BMSCs), and to investigate further any interactions between the mitogen‐activated protein kinase (MAPK) and transforming growth factor‐β1 (TGF‐β1)/Smads pathway in the process.Materials and methods:  Chondrogenic differentiation of rat BMSCs was initiated in micromass culture, in the presence of TGF‐β1, for 2 weeks. ERK1/2 and p38 kinase activities were investigated by Western Blot analysis. Specific MAPK inhibitors PD98059 and SB20350 were employed to investigate regulatory effects of MEK/ERK and p38 signals on gene expression of chondrocyte‐specific markers, and TGF‐β1 downstream pathways of Smad2/3.Results:  ERK1/2 was phosphorylated in a rapid but transient manner, whereas p38 was activated in a slow and sustained way. The two MAPK subtypes played opposing roles in mediating transcription of cartilage‐specific genes for Col2α and aggrecan. TGF‐β1‐stimulated gene expression of chondrogenic regulators, Sox9, Runx2 and Ihh, was also affected by activity of PD98059 and SB203580, to different degrees. However, influences of MAPK inhibitors on gene expression were relatively minor when not treated with TGF‐β1. In addition, gene transcription of Smad2/3 was significantly upregulated by TGF‐β1, but was regulated more subtly by treatment with MAPK inhibitors.Conclusions:  MAPK subtypes seemed to regulate chondrogenesis with a delicate balance, interacting with the TGF‐β1/Smads signalling pathway.
Spontaneous immortalization of neural crest‐derived corneal progenitor cells after chromosomal aberration
Authors: Brandl C. , Kaesbauer J. , Weber B. H. F. , Morsczeck C. 
Published: June 2010

AbstractObjectives:  In a previous study, we have reported the existence of neural crest‐derived stem cell‐like cells originating from the corneal limbus of juvenile mice (termed murine corneal cells, MCCs). To yield a sufficient number of MCCs, for example, for cell‐therapy approaches, here we have investigated MCCs’ ability for extensive proliferation, and we have evaluated their stem cell qualities and genetic stability after large‐scale culture.Materials and methods:  MCCs were established from corneal limbal tissue of juvenile mice. To determine their cell proliferation and self‐renewing potential, MTT tests and an estimation of colony forming unit efficiency were carried out. Multipotency of cell differentiation was examined by applying adipogenic and osteogenic differentiation protocols. Moreover, karyotyping was performed and expression of stem cell markers and cell cycle‐associated genes was analysed.Results:  MCCs, as primary cells, could be cultured for more than 60 passages. We observed increased cell proliferation and high number of colony forming units (CFUs) after extensive culture. Interestingly, there were no changes in expression of MCC markers. Furthermore, cell differentiation potentials remained comparable with MCCs at early passages. However, karyotyping revealed numeric chromosomal aberrations at higher passages. Moreover, tumour suppressor genes such as p16 and p21 were found to be down‐regulated after large‐scale cell culture.Conclusions:  MCCs immortalize spontaneously after extensive cell culture, but still demonstrate stem cell‐like qualities.
Mach–Zehnder interference microscopy optically records electrically stimulated cellular activity in unstained nerve cells
Authors: KAUL R.A. , MAHLMANN D.M. , LOOSEN P. 
Published: June 2010

SummaryDual‐beam white light interference microscopy monitors changes in the optical density of the investigated object with high sensitivity. We report on the recording of dynamic changes in a neuron's optical density evoked by extracellular electrical stimulation. These recorded changes were analysed and unambiguously connected to the investigated object, an invertebrate neuron of the pond snail Lymnaea stagnalis. The results provide evidence for the method's applicability in visualizing cellular dynamics purely by evaluating changes in a cell's optical properties.
Determining the age of individual Lepeophtheirus salmonis (Krøyer, 1837) copepodids by measuring stored lipid volume; proof of principle
Authors: COOK P.F. , MCBEATH S.J. , BRICKNELL I.R. , BRON J.E. 
Published: June 2010

SummaryConfocal microscopy has facilitated measurement of stained lipid volume in Lepeophtheirus salmonis copepodid larvae. Quantity of lipid, location and morphology of vesicles may allow an estimate of age and viability
Are indirect genetic benefits associated with polyandry? Testing predictions in a natural population of lemon sharks
Authors: DiBATTISTA JOSEPH D. , FELDHEIM KEVIN A. , GRUBER SAMUEL H. , HENDRY ANDREW P. 
Published: June 2010

AbstractMultiple mating has clear fitness benefits for males, but uncertain benefits and costs for females. We tested for indirect genetic benefits of polyandry in a natural population, by using data from a long‐term genetic and demographic study of lemon sharks (Negaprion brevirostris) at Bimini, Bahamas. To do so, we followed the fates of individuals from six cohorts (450 age‐0 and 254 age‐1 fish) in relation to their individual level of genetic variation, and whether they were from polyandrous or monoandrous litters. We find that offspring from polyandrous litters did not have a greater genetic diversity or greater survival than did the offspring of monoandrous litters. We also find no evidence of positive associations between individual offspring genetic diversity metrics and our surrogate measure of fitness (i.e. survival). In fact, age‐1 individuals with fewer heterozygous microsatellite loci and more genetically similar parents were more likely to survive to age‐2. Thus, polyandry in female lemon sharks does not appear to be adaptive from the perspective of indirect genetic benefits to offspring. It may instead be the result of convenience polyandry, whereby females mate multiply to avoid harassment by males. Our inability to find indirect genetic benefits of polyandry despite detailed pedigree and survival information suggests the need for similar assessments in other natural populations.
Microbiological risk of anaesthetic breathing circuits after extended use
Authors: HARTMANN D. , JUNG M. , NEUBERT T. R. , SUSIN C. , NONNENMACHER C. , MUTTERS R. 
Published: June 2010

Introduction: Daily change of breathing circuits in the operating theatre requires a lot of resources and is time and labour consuming. The extended use of breathing circuits could reduce the workload of the staff and health care costs. The aim of the present study was to evaluate the contamination rate of anaesthesia breathing circuits changed after 24, 48 or 72 h of use.Materials: The study was performed as an experimental observational study. Microbiological samples were taken from 112 breathing systems including both parts of the ventilator circuit (inspiration and expiration) and analysed using microbiological standard techniques. Breathing circuits were changed according to three different schedules. In the 24‐h group, breathing circuits were changed every day, whereas in the 48‐h group changing of the circuits took place on Mondays, Wednesdays and Fridays. A period of 72 h operating use was tested on weekends.Results: A total of 112 breathing systems comprised of 224 samples from the ventilator circuit were tested for bacteria and yeast contamination. A non‐significant increase in the contamination rate was observed with the extended use for breathing circuits (24 h: 3.33%, 48 h: 4.35% and 72 h: 5.56%; P for trend=0.66). Similarly, no significant increase in contamination rate could be observed at the sample level (24 h: 1.67%, 48 h: 3.26% and 72 h: 2.78%; P for trend=0.71).Conclusion: The extended use of breathing circuits for 48 and 72 h does not increase significantly the risk of contamination, provided that HME filters are changed separately for every patient.
Objectively measured physical activity and obesity prevention in children, adolescents and adults: a systematic review of prospective studies
Authors: Wilks D. C. , Besson H. , Lindroos A. K. , Ekelund U. 
Published: June 2010

SummaryThis study aimed at synthesizing the prospective associations between measured physical activity (PA) and change in adiposity in children, adolescents and adults following from two previous reviews. Search terms were adapted and a systematic literature search was conducted (January 2000–September 2008) and later updated (up to October 2009), considering observational and intervention studies of weight gain that measured both PA and body composition. Sixteen observational studies (six comprising adults) and five trials (one comprising adults) were eligible. For consistency, whenever possible either baseline PA energy expenditure or accelerometer output (counts min−1) and change in per cent body fat were the extracted exposure and outcome measures. Results of observational studies suggest that PA is not strongly prospectively related with adiposity: five studies on children and three on adults reported no association between baseline PA and change in adiposity, one study found a weak positive association and the other studies observed a weak negative association. Negative associations were more frequently observed in studies that analysed the association between change in the exposure and outcome. Intervention studies show generally no effect on either PA or adiposity. In conclusion, despite the well‐established health benefits of PA, it may not be a key determinant of excessive gain in adiposity.