While regulation of the activity of developmental control genes at the transcriptional level as well as by specific miRNA-based degradation are intensively studied, little is known whether general ...cellular mechanisms controlling mRNA decay may contribute to differential stability of mRNAs of developmental control genes. Here, we investigate whether a mutation in the deadenylation dependent mRNA decay pathway may reveal differential effects on developmental mechanisms, using dopaminergic differentiation in the zebrafish brain as model system. In a zebrafish genetic screen aimed at identifying genes controlling dopaminergic neuron development we isolated the m1061 mutation that selectively caused increased dopaminergic differentiation in the caudal hypothalamus, while other dopaminergic groups were not affected. Positional cloning revealed that m1061 causes a premature stop codon in the cnot8 open reading frame. Cnot8 is a component of the Ccr4-Not complex and displays deadenylase activity, which is required for removal of the poly (A) tail in bulk mRNA turnover. Analyses of expression of developmental regulators indicate that loss of Cnot8 activity results in increased mRNA in situ hybridization signal levels for a subset of developmental control genes. We show that in the area of caudal hypothalamic dopaminergic differentiation, mRNA levels for several components of the FGF signaling pathway, including Fgf3, FGF receptors, and FGF target genes, are increased. Pharmacological inhibition of FGF signaling or a mutation in the fgf3 gene can compensate the gain of caudal hypothalamic dopaminergic neurons in cnot8m1061 mutants, indicating a role for Fgf3 in control of development of this dopaminergic population. The cnot8m1061 mutant phenotype provides an in vivo system to study roles of the Cnot8 deadenylase component of the mRNA decay pathway in vertebrate development. Our data indicate that attenuation of Cnot8 activity differentially affects mRNA levels of developmental control genes.
A new measurement of inclusive-jet cross sections in the Breit frame in neutral current deep inelastic scattering using the ZEUS detector at the HERA collider is presented. The data were taken in the ...years 2004–2007 at a centre-of-mass energy of
318
GeV
and correspond to an integrated luminosity of
347
pb
-
1
. The jets were reconstructed using the
k
t
-algorithm in the Breit reference frame. They have been measured as a function of the squared momentum transfer,
Q
2
, and the transverse momentum of the jets in the Breit frame,
p
⊥
,
Breit
. The measured jet cross sections are compared to previous measurements and to perturbative QCD predictions. The measurement has been used in a next-to-next-to-leading-order QCD analysis to perform a simultaneous determination of parton distribution functions of the proton and the strong coupling, resulting in a value of
α
s
(
M
Z
2
)
=
0.1142
±
0.0017
(experimental/fit)
-
0.0007
+
0.0006
(model/parameterisation)
-
0.0004
+
0.0006
(scale)
, whose accuracy is improved compared to similar measurements. In addition, the running of the strong coupling is demonstrated using data obtained at different scales.
In Kenya,
Thrips tabaci Lind., is an important constraint to onion production. The current strategy to use synthetic pesticides is inadequate and unsustainable. An isolate of
Metarhizium anisopliae ...(Metsch.) Sorok. with high pathogenicity to legume thrips,
Megalurothrips sjostedti, and western flower thrips,
Frankliniella occidentalis, was tested in field trials as a potential alternative for control of onion thrips. Weekly and bi-weekly applications of the fungus
M. anisopliae and bi-weekly spray of the chemical insecticide dimethoate (Rogor
® 50) were compared for 3 seasons.
M. anisopliae was applied at the rate of 1×10
11
conidia
ha
−1 and dimethoate was applied at the recommended rate of 17.5
g
a.i.
ha
−1. In all the trials, thrips density and damage were significantly lower in the fungal and chemical insecticide treatments compared with the untreated control. Onion bulb yield did not differ significantly among the treatments during the first season trial. However, in the second season trial, dimethoate-treated plots provided the greatest bulb yield (17
metric
tons
ha
−1) and in the third season trial,
M. anisopliae applied weekly recorded the highest yield (24
metric
tons
ha
−1). With the exception of spiders, densities of nontarget organisms were higher in plots treated with
M. anisopliae than in dimethoate-treated plots. The results indicate the potential of using
M. anisopliae for the control of
T. tabaci while protecting biodiversity in the onion agroecosystem.
Post-traumatic stress disorder (PTSD) has major public health significance. Evidence that PTSD may be associated with premature senescence (early or accelerated aging) would have major implications ...for quality of life and healthcare policy. We conducted a comprehensive review of published empirical studies relevant to early aging in PTSD.
Our search included the PubMed, PsycINFO, and PILOTS databases for empirical reports published since the year 2000 relevant to early senescence and PTSD, including: 1) biomarkers of senescence (leukocyte telomere length LTL and pro-inflammatory markers), 2) prevalence of senescence-associated medical conditions, and 3) mortality rates.
All six studies examining LTL indicated reduced LTL in PTSD (pooled Cohen's d = 0.76). We also found consistent evidence of increased pro-inflammatory markers in PTSD (mean Cohen's ds), including C-reactive protein = 0.18, Interleukin-1 beta = 0.44, Interleukin-6 = 0.78, and tumor necrosis factor alpha = 0.81. The majority of reviewed studies also indicated increased medical comorbidity among several targeted conditions known to be associated with normal aging, including cardiovascular disease, type 2 diabetes mellitus, gastrointestinal ulcer disease, and dementia. We also found seven of 10 studies indicated PTSD to be associated with earlier mortality (average hazard ratio: 1.29).
In short, evidence from multiple lines of investigation suggests that PTSD may be associated with a phenotype of accelerated senescence. Further research is critical to understand the nature of this association. There may be a need to re-conceptualize PTSD beyond the boundaries of mental illness, and instead as a full systemic disorder.
From 2001 onwards,
Diadegma semiclausum, an exotic parasitoid of the diamondback moth, was introduced and released in Kenya, Tanzania and Uganda. Contrary to common practice where thousands of ...parasitoids are released, we released very low numbers, 125 females in Kenya, 160 in Uganda and 350 in Tanzania. About 2 years after this single release, the establishment and natural spread of the parasitoids was assessed in all release areas. Two methods were employed: in Kenya, a grid with equidistant points in the four cardinal directions (2–50
km) with the release area in the centre was used and collections were made 27 months after release at the predetermined points. The parasitoid was found up to a distance of 30
km from the release site. In Tanzania and Uganda, surveys were made starting from the release area following major roads. At regular intervals, fields were inspected and their position recorded with a Geographic Positioning System (GPS). The results of a field survey conducted 24 months after release indicate that in Tanzania, the parasitoid had spread >20
km from the release site while in Uganda, the spread was >30
km. Wherever
D. semiclausum was collected, it was the major parasitoid species. Indigenous parasitoids collected were
Oomyzus sokolowskii (Hym.: Eulophidae),
Diadegma mollipla (Hym.: Ichneumonidae) and
Apanteles sp. (Hym.: Braconidae). Overall parasitism and the contribution of the introduced parasitoid to the control of diamondback moth population tended to decrease with increasing distance from the release point. The introduced parasitoid had displaced the indigenous species wherever it was well established.
Plutella xylostella is the most abundant and damaging pest of cruciferous crops in Kenya and has gained economic importance over the years. During a survey conducted in the major crucifer areas of ...Kenya a number of wild crucifers recorded in the region were found infested with diamondback moth. As a result, research was conducted in the laboratory and greenhouse to investigate whether exotic parasitoids recently introduced would develop and survive on the wild crucifers. Experiments were conducted on development, survival, reproductive potential and parasitism of
Cotesia plutellae and
Diadegma semiclausum on cultivated Brassica (
Brassica oleracea var.
capitata and
B. oleracea var.
acephala) and wild crucifers (
Erucastrum arabicum,
Raphanus raphanistrum,
Rorippa micrantha,
Rorippa nudiuscula and
Brassica juncea). Both diamondback moth and parasitoids survived and developed on the wild crucifers. Egg-larval period of
C. plutellae was shortest on
E. arabicum (7.4 days) and longest on
R. raphanistrum (9.3 days) while that of
D. semiclausum was shortest on
B. juncea (6.7 days).
Ro. micrantha and
R. raphanistrum recorded the lowest cocoon weight of 1.67
mg and 7.1
mg from
C. plutellae and
D. semiclausum, respectively. Longest pupal period was recorded on
C. plutellae and
D. semiclausum reared on
B. oleracea var.
acephala and
Ro. micrantha, respectively. Egg-adult development time of
C. plutellae was significantly longer on
R. raphanistrum (15.2 days) and shortest on
B. juncea and
E. arabicum (12.2 days) while that of
D. semiclausum was longest on
Ro. micrantha (16.1 days) and shortest on
E. arabicum (12.4 days). Mortality was higher on wild crucifers than on the cultivated Brassica species. In free choice tests, parasitism and parasitoid emergence were significantly higher on cultivated cultivars. Relatively higher percentage of larvae exposed to
C. plutellae was not re-collected.
The results suggest that wild crucifers can support development of the exotic parasitoids and thus provide refugia, thereby lowering the risk of local parasitoid extinction after pesticide application or harvesting. However, they might also be a source for diamondback moth and their presence near cultivated crucifer fields could lead to early population build-up.
The RNA-binding protein
Arabidopsis thaliana
glycine-rich RNA-binding protein 7 (
At
GRP7) regulates the steady-state abundance of numerous target transcripts in
A. thaliana
. Here we show that the
...GA1
and
GA2
transcripts encoding the first enzymes of the gibberellin biosynthetic pathway are expressed at reduced levels in transgenic plants ectopically over-expressing
At
GRP7 (
At
GRP7-ox plants). Furthermore, the levels of the bioactive phytohormone GA
4
as well as of several intermediates of the GA biosynthetic pathway are reduced in
At
GRP7-ox plants. The transgenic plants show a reduced length of the vegetative stem. The application of exogenous GA largely reverses the phenotype by increasing the number of vegetative internodes.
At
GRP7-ox plants flower with fewer leaves than wt plants, suggesting that the floral promotive effect of
At
GRP7 bypasses the effect of a reduced GA level in
At
GRP7-ox plants. Upon GA treatment,
At
GRP7-ox plants flower only slightly earlier than wild type plants. Thus, exogenous GA has only a small additional effect in reducing the number of leaves at the onset of flowering in
At
GRP7-ox plants.
A locally available anthocorid predator,
Orius albidipennis Reuter, was evaluated as a candidate biocontrol agent for
Megalurothrips sjostedti Trybom, a major pest of French beans,
Phaseolus vulgaris ...(L), in Kenya. The functional response of adult
O. albidipennis to larval and adult
M. sjostedti was studied at 15, 25, and 28 °C and densities of 5, 10, 20, and 30 larval and adult
M. sjostedti per cage, over 24 h. More larvae and adult
M. sjostedti were killed at the higher densities and with an increase in temperature. The data provided good fit to both type I and II functional response models. Attack rates increased with temperature for both the second instar larva and adult
M. sjostedti. Handling times for the larvae decreased with an increase in temperature while those for the adults increased with increase in temperature. The implications of these results are discussed.
Measurements of open charm and beauty production cross sections in deep inelastic
ep
scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections are obtained in the ...kinematic range of negative four-momentum transfer squared of the photon
2.5
GeV
2
≤
Q
2
≤
2000
GeV
2
and Bjorken scaling variable
3
·
10
-
5
≤
x
Bj
≤
5
·
10
-
2
. The combination method accounts for the correlations of the statistical and systematic uncertainties among the different datasets. Perturbative QCD calculations are compared to the combined data. A next-to-leading order QCD analysis is performed using these data together with the combined inclusive deep inelastic scattering cross sections from HERA. The running charm- and beauty-quark masses are determined as
m
c
(
m
c
)
=
1
.
290
-
0.041
+
0.046
(
exp
/
fit
)
-
0.014
+
0.062
(
model
)
-
0.031
+
0.003
(
parameterisation
)
GeV and
m
b
(
m
b
)
=
4
.
049
-
0.109
+
0.104
(
exp
/
fit
)
-
0.032
+
0.090
(
model
)
-
0.031
+
0.001
(
parameterisation
)
GeV
.
Polycystic ovary syndrome (PCOS) is associated with elevated androgen and luteinizing hormone (LH) secretion and with oligo/anovulation. Evidence indicates that elevated androgens impair sex steroid ...hormone feedback regulation of pulsatile LH secretion. Hyperandrogenemia in PCOS may also disrupt the preovulatory LH surge. The mechanisms through which this might occur, however, are not fully understood. Kisspeptin (KISS1) neurons of the rostral periventricular area of the third ventricle (RP3V) convey hormonal cues to gonadotropin-releasing hormone (GnRH) neurons. In rodents, the preovulatory surge is triggered by these hormonal cues and coincident timing signals from the central circadian clock in the suprachiasmatic nucleus (SCN). Timing signals are relayed to GnRH neurons, in part,
projections from SCN arginine-vasopressin (AVP) neurons to RP3V
neurons. Because rodent SCN cells express androgen receptors (AR), we hypothesized that these circuits are impaired by elevated androgens in a mouse model of PCOS. In prenatally androgen-treated (PNA) female mice, SCN
expression was significantly increased compared to that found in prenatally vehicle-treated mice. A similar trend was seen in the number of
-positive SCN cells expressing
. In the RP3V, the number of kisspeptin neurons was preserved. Anterograde tract-tracing, however, revealed reduced SCN
neuron projections to the RP3V and a significantly lower proportion of RP3V
neurons with close appositions from SCN
fibers. Functional assessments showed, on the other hand, that RP3V
neuron responses to AVP were maintained in PNA mice. These findings indicate that PNA changes some of the neural circuits that regulate the preovulatory surge. These impairments might contribute to ovulatory dysfunction in PNA mice modeling PCOS.
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