268 research outputs found
Sampling design may obscure species–area relationships in landscape-scale field studies
We investigated 1) the role of area per se in explaining anuran species richness on reservoir forest islands, after controlling for several confounding factors. We also assessed 2) how sampling design affects the inferential power of island species–area relationships (ISARs) aiming to 3) provide guidelines to yield reliable estimates of area-induced species losses in patchy systems. We surveyed anurans with autonomous recording units at 151 plots located on 74 islands and four continuous forest sites at the Balbina Hydroelectric Reservoir landscape, central Brazilian Amazonia. We applied semi-log ISAR models to assess the effect of sampling design on the fit and slope of species–area curves. To do so, we subsampled our surveyed islands following both a 1) stratified and 2) non-stratified random selection of 5, 10, 15, 20 and 25 islands covering 1) the full range in island size (0.45–1699 ha) and 2) only islands smaller than 100 ha, respectively. We also compiled 25 datasets from the literature to assess the generality of our findings. Island size explained ca half of the variation in species richness. The fit and slope of species–area curves were affected mainly by the range in island size considered, and to a very small extent by the number of islands surveyed. In our literature review, all datasets covering a range of patch sizes larger than 300 ha yielded a positive ISAR, whereas the number of patches alone did not affect the detection of ISARs. We conclude that 1) area per se plays a major role in explaining anuran species richness on forest islands within an Amazonian anthropogenic archipelago; 2) the inferential power of island species–area relationships is severely degraded by sub-optimal sampling designs; 3) at least 10 habitat patches spanning three orders of magnitude in size should be surveyed to yield reliable species–area estimates in patchy systems
Produtividade de grãos e componentes de produção da canola de acordo com fontes e doses de nitrogênio.
Avalia a resposta da canola a fontes e doses de nitrogênio aplicadas na semeadura. O experimento foi conduzido em Latossolo Vermelho distroférrico típico, com textura muito argilosa. Utilizou-se delineamento experimental de blocos ao acaso, em arranjo fatorial 7x2, com sete doses de N em superfície na semeadura (0, 20, 40, 60, 80, 100 e 120 kg ha‑1), duas fontes de N (sulfato de amônio e ureia) e quatro repetições. O experimento foi realizado com o híbrido Hyola 61, por dois anos, e foram avaliadas as seguintes variáveis: altura de planta, número de plantas por metro quadrado, massa de matéria seca da parte aérea, massa de síliquas por planta, massa de mil grãos, produtividade de grãos, e teores de proteína e de óleo nos grãos. As variáveis não foram influenciadas pelas fontes de N. A maior produtividade de grãos é alcançada com 88 kg ha‑1 de N. Doses crescentes de N aumentam os teores de proteína e diminuem os de óleo nos grãos de canola
An ovulating follicle presenting as a testicular mass in a teenage patient with ovotesticular DSD
Construction of a scientific abstract
An abstract is a brief summary of a research article, thesis, review, conference
proceeding, or any in-depth analysis of a particular subject [1]. It is used to help the
reader quickly ascertain the authors’ principle messages.
The aim of this text is to strengthen the understanding of abstract writing, define its
specific components, and to help the writer evaluate and complete their abstract with
enhanced clarity and quality [2].
Typically, the academic research abstract contains four elements: objective and study
design, materials and methods, results, and discussion/conclusions. During peer
review, it is important that authors adhere to this format, as reviewers often evaluate
these parts separately
Time evolution of ground motion-dependent depolarisation at linear colliders
Future linear colliders plan to collide polarised beams and the planned
physics reach requires knowledge of the state of polarisation as precisely as
possible. The polarised beams can undergo depolarisation due to various
mechanisms. In order to quantify the uncertainty due to depolarisation, spin
tracking simulations in the International Linear Collider (ILC) Beam Delivery
System (BDS) and at the Interaction Point (IP) have been performed. Spin
tracking in the BDS was achieved using the BMAD subroutine library, and the
CAIN program was used to do spin tracking through the beam-beam collision.
Assuming initially aligned beamline elements in the BDS, a ground motion model
was applied to obtain realistic random misalignments over various time scales.
Depolarisation at the level of 0.1% occurs within a day of ground motion at a
noisy site. Depolarisation at the IP also exceeds 0.1% for the nominal
parameter sets for both the ILC and for the Compact Linear Collider (CLIC).
Theoretical work is underway to include radiative corrections in the
depolarisation processes and simulation of the depolarisation through the
entire collider is envisaged.Comment: 8 pages, 4 figures, PST09 proceedings; Proceedings of the 13th
International Workshop on Polarised Sources, Targets and Polarimetry 2009,
World Scientific 201
The impact of COVID-19 on research
This article is made available for unrestricted research re-use and secondary analysis in any form or be any means with acknowledgement of the original source. These permissions are granted for the duration of the World Health Organization (WHO) declaration of COVID-19 as a global pandemic.Coronavirus disease 2019 (COVID-19) has swept across the globe causing hundreds of thousands of deaths, shutting down economies, closing borders and wreaking havoc on an unprecedented scale. It has strained healthcare services and personnel to the brink in many regions and will certainly deeply mark medical research both in the short and long-term
Comparison of Intraoperative and Early Postoperative Outcomes of Caudal Versus Dorsal Penile Nerve Blocks for Outpatient Penile Surgeries
Objective
To compare intraoperative and 1-hour postoperative outcomes in caudal versus dorsal penile nerve block (DPNB) patients undergoing penile surgeries.
Material and Methods
We performed a retrospective cohort study of males 3. Secondary outcomes were intraoperative/post-anesthesia care unit (PACU) narcotics, pre-incision anesthesia time, adjusted operating room charges and complications. We performed bivariate and multivariable analyses controlling for demographic/procedure characteristics and clustering by surgeon.
Results
Of 738 patients, (mean age 2.1 years) 74.1% had a caudal. DPNB patients were more likely to have a maximum pain score >3 (19.5% vs. 8.1%, p 3 (95% CI 1.7- 4.4, p<0.0001) and 5.2 times the odds of intraoperative/PACU narcotic administration (95% CI 3.3-8.1, p<0.0001). In multivariable analyses, caudal patients had longer pre-incision anesthesia time (27.9 ± 7.4 vs. 19.5 ± 6.6 minutes, p<0.0001) and higher adjusted operating room charges (9,402 ± 3741, p=0.01).
Conclusion
Caudal blocks may offer a small advantage in the immediate postoperative period although cost-effectiveness is unproven
A Comparative Analysis of Gene Expression Patterns and Cell Phenotypes between Cervical and Peripheral Blood Mononuclear Cells
Studies of the immunological environment in the female genital tract (FGT) are critical for the development of vaccines or microbicides to halt the spread of sexually transmitted infections. Challenges arise due to the difficulties of sampling from this site, and the majority of studies have been conducted utilising peripheral blood mononuclear cells. Identifying functional differences between immune cells of the FGT and peripheral blood would aid in our understanding of mucosal immunology. We compared the gene expression profile of mononuclear cells at these two sites. Messenger RNA expression analysis was performed using gene expression arrays on matched cervical mononuclear cells and peripheral blood mononuclear cells. Further cellular phenotyping was done by 10 colour flow cytometry. Of the 22,185 genes expressed by these samples, 5345 genes were significantly differentially expressed between the cell populations. Most differences can be explained by significantly lower levels of T and B cells and higher levels of macrophages and dendritic cells in the FGT compared with peripheral blood. Several immunologically relevant pathways such as apoptosis and innate immune signalling, and a variety of cytokines and cytokine receptors were differentially expressed. This study highlights the importance of the unique immunological environment of the FGT and identifies important differences between systemic and mucosal immune compartments
How to more effectively determine what is true: The limits of intuition
The plethora of scientific data and explosion of published materials often leave it challenging to develop a clear and concise overview of many scientific topics. A number of factors may contribute to our misunderstanding. It is the focus of this article to describe primary reasons for failure to establish a clear, factual and functional understanding regarding scientific areas of inquiry
Microarray Analysis of HIV Resistant Female Sex Workers Reveal a Gene Expression Signature Pattern Reminiscent of a Lowered Immune Activation State
To identify novel biomarkers for HIV-1 resistance, including pathways that may be critical in anti-HIV-1 vaccine design, we carried out a gene expression analysis on blood samples obtained from HIV-1 highly exposed seronegatives (HESN) from a commercial sex worker cohort in Nairobi and compared their profiles to HIV-1 negative controls. Whole blood samples were collected from 43 HIV-1 resistant sex workers and a similar number of controls. Total RNA was extracted and hybridized to the Affymetrix HUG 133 Plus 2.0 micro arrays (Affymetrix, Santa Clara CA). Output data was analysed through ArrayAssist software (Agilent, San Jose CA). More than 2,274 probe sets were differentially expressed in the HESN as compared to the control group (fold change ≥1.3; p value ≤0.0001, FDR <0.05). Unsupervised hierarchical clustering of the differentially expressed genes readily distinguished HESNs from controls. Pathway analysis through the KEGG signaling database revealed a majority of the impacted pathways (13 of 15, 87%) had genes that were significantly down regulated. The most down expressed pathways were glycolysis/gluconeogenesis, pentose phosphate, phosphatidyl inositol, natural killer cell cytotoxicity and T-cell receptor signaling. Ribosomal protein synthesis and tight junction genes were up regulated. We infer that the hallmark of HIV-1 resistance is down regulation of genes in key signaling pathways that HIV-1 depends on for infection
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