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991.
ZINBA (Zero-Inflated Negative Binomial Algorithm) identifies genomic regions enriched in a variety of ChIP-seq and related
next-generation sequencing experiments (DNA-seq), calling both broad and narrow modes of enrichment across a range of signal-to-noise
ratios. ZINBA models and accounts for factors that co-vary with background or experimental signal, such as G/C content, and
identifies enrichment in genomes with complex local copy number variations. ZINBA provides a single unified framework for
analyzing DNA-seq experiments in challenging genomic contexts. 相似文献
992.
Christof Janko Stefan Linke Thomas Romig Dorothea Thoma Wolfgang Schröder Andreas König 《European Journal of Wildlife Research》2011,57(5):1033-1042
This study investigated the epidemiological and ecological factors to assess the infection pressure of alveolar echinococcosis
to human which are living in villages and small towns. Foxes and fox faeces were examined for Echinococcus multilocularis and foxes were observed by radio telemetry in Upper Bavaria, Germany. Forty-three percent of the village foxes (n = 65) had been infected with E. multilocularis. This prevalence rate did not differ significantly from the prevalence among rural foxes, which was 39% (n = 33; χ
2 = 0.12, df = 1, p = 0.727) determined by the intestinal scraping technique. PCR analyses of fox faeces showed a higher infection rate of 35%
(n = 26) among rural foxes than among foxes in villages and small towns (26%, n = 69; χ
2 = 0.68, df = 1, p = 0.411). One quarter of the fox faecal samples come from private gardens of residents. The radio-tracking study on 17 foxes
showed that foxes preferred the built-up area and grassland outside the villages. Village foxes concentrated their activity
within a range of 500 m around the settlement. Sixty-four percent of all bearings for radio-tracked foxes showed positions
in areas outside the town, and 36% of bearings were within the settlement. Village foxes, which are infected with E. multilocularis, are able to carry the parasite continuously into settlements and fox faeces present an immediate source of infection to
humans, especially within their gardens. Therefore, foxes are responsible for environmental E. multilocularis egg contamination in the vicinity of humans, leading to an infection risk to inhabitants of villages and small towns. 相似文献
993.
Pfefferle D Heistermann M Pirow R Hodges JK Fischer J 《International journal of primatology》2011,32(4):992-1006
Females of many Old World primates produce conspicuous vocalizations in combination with copulations. Indirect evidence exists
that in Barbary macaques (Macaca sylvanus), the structure of these copulation calls is related to changes in reproductive hormone levels. However, the structure of
these calls does not vary significantly around the timing of ovulation when estrogen and progestogen levels show marked changes.
We here aimed to clarify this paradox by investigating how the steroid hormones estrogen and progesterone are related to changes
in the acoustic structure of copulation calls. We collected data on semi-free-ranging Barbary macaques in Gibraltar and at
La Forêt des Singes in Rocamadour, France. We determined estrogen and progestogen concentrations from fecal samples and combined
them with a fine-grained structural analysis of female copulation calls (N = 775 calls of 11 females). Our analysis indicates a time lag of 3 d between changes in fecal hormone levels, adjusted for
the excretion lag time, and in the acoustic structure of copulation calls. Specifically, we found that estrogen increased
the duration and frequency of the calls, whereas progestogen had an antagonistic effect. Importantly, however, variation in
acoustic variables did not track short-term changes such as the peak in estrogen occurring around the timing of ovulation.
Taken together, our results help to explain why female Barbary macaque copulation calls are related to changes in hormone
levels but fail to indicate the fertile phase. 相似文献
994.
The application of the synthetic auxin 3,5,6-trichloro-2-piridyloxyacetic acid (3,5,6-TPA) isopropyl ester at the onset of
cell enlargement stage, significantly thinned fruitlets in ‘Clausellina’ Satsuma mandarin. The magnitude of the response was
related to the concentration applied, increasing the percentage of abscised fruit with higher concentrations, which was up
to 70% at 25 mg l−1. The magnitude of the response also depended on the organ subject to treatment, abscission being greater when applied to
the leaves rather than to fruit. Results suggest that a photosynthetic disorder was responsible for a reduction in fruit growth
rate, triggering abscission mechanisms producing ethylene and abscission. 相似文献
995.
996.
Klaus S. Larsen Andreas Ibrom Claus Beier Sven Jonasson Anders Michelsen 《Biogeochemistry》2007,85(2):201-213
We measured net ecosystem CO2 flux (F
n) and ecosystem respiration (R
E), and estimated gross ecosystem photosynthesis (P
g) by difference, for two years in a temperate heath ecosystem using a chamber method. The exchange rates of carbon were high
and of similar magnitude as for productive forest ecosystems with a net ecosystem carbon gain during the second year of 293 ± 11 g C m−2 year−1 showing that the carbon sink strength of heather-dominated ecosystems may be considerable when C. vulgaris is in the building phase of its life cycle. The estimated gross ecosystem photosynthesis and ecosystem respiration from October
to March was 22% and 30% of annual flux, respectively, suggesting that both cold-season carbon gain and loss were important
in the annual carbon cycle of the ecosystem. Model fit of R
E of a classic, first-order exponential equation related to temperature (second year; R
2 = 0.65) was improved when the P
g rate was incorporated into the model (second year; R
2 = 0.79), suggesting that daytime R
E increased with increasing photosynthesis. Furthermore, the temperature sensitivity of R
E decreased from apparent Q
10 values of 3.3 to 3.9 by the classic equation to a more realistic Q
10 of 2.5 by the modified model. The model introduces R
photo, which describes the part of respiration being tightly coupled to the photosynthetic rate. It makes up 5% of the assimilated
carbon dioxide flux at 0°C and 35% at 20°C implying a high sensitivity of respiration to photosynthesis during summer. The
simple model provides an easily applied, non-intrusive tool for investigating seasonal trends in the relationship between
ecosystem carbon sequestration and respiration. 相似文献
997.
998.
Microsomal prostaglandin E2 synthase (mPGES-1) has been identified recently as a novel target for treating pain and inflammation. The aim of this study
is to understand the binding affinities of reported inhibitors for mPGES-1 and further to design potential new mPGES-1 inhibitors.
3D-QSAR-CoMFA (comparative molecular field analysis) and CoMSIA (comparative molecular similarity indices analysis) - techniques
were employed on a series of indole derivatives that act as selective mPGES-1 inhibitors. The lowest energy conformer of the
most active compound obtained from systematic conformational search was used as a template for the alignment of 32 compounds.
The models obtained were used to predict the activities of the test set of eight compounds, and the predicted values were
in good agreement with the experimental results. The 3D-QSAR models derived from the training set of 24 compounds were all
statistically significant (CoMFA; q
2 = 0.89, r
2 = 0.95, , and CoMSIA; q
2 = 0.84, r
2 = 0.93, , ). Contour plots generated for the CoMFA and CoMSIA models reveal useful clues for improving the activity of mPGES-1 inhibitors.
In particular, substitutions of an electronegative fluorine atom or a bulky hydrophilic phenoxy group at the meta or para positions of the biphenyl rings might improve inhibitory activity. A plausible binding mode between the ligands and mPGES-1
is also proposed. 相似文献
999.
Geometric morphometric studies are increasingly becoming common in systematics and palaeontology. The samples in such studies
are often small, due to the paucity of material available for analysis. However, very few studies have tried to assess the
impact of sampling error on analytical results. Here, this issue is addressed empirically using repeated randomized selection
experiments to build progressively smaller samples from an original dataset of ∼400 vervet monkey (Cercopithecus aethiops) skulls. Size and shape parameters (including mean size and shape, size and shape variances, angles of allometric trajectories)
that are commonly used in geometric morphometric studies, are estimated first in the original sample and then in the random
subsamples. Estimates are then compared to give an indication of what is the minimum desirable sample size for each parameter.
Mean size, standard deviation of size and variance of shape are found to be fairly accurate even in relatively small samples.
In contrast, mean shapes and angles between static allometric trajectories are strongly affected by sampling error. If confirmed
in other groups, our findings may have substantial implications for studies of morphological variation in present and fossil
species. By performing rarefaction analyses like those presented in our study, morphometricians can be easily provided with
important clues on how a simple but crucial factor like sample size can alter results of their studies. 相似文献
1000.