scholarly journals The underground sex life of the Guatemalan Spike-thumb Frog (Plectrohyla guatemalensis)

2020 ◽  
Vol 15 (4) ◽  
pp. 551-559
Author(s):  
Sergio González-Mollinedo ◽  
Alejandro Mármol-Kattán

Two populations of Plectrohyla guatemalensis from two different sites in Sacatepéquez, Guatemala, were monitored for three consecutive rainy seasons, and noteworthy reproductive behavior was observed. The objective of the surveys was to assess the impact of nearby high-tension power lines, but additional information could be obtained. Our observations that male vocalizations to attract females occurred in the crevices of rocks in streams, inside which females lay eggs, suggest that the species’ reproduction is closely linked to the presence of such crevices. Any clutches were then guarded by the male until hatching. We inferred the existence of male-male competition for gaining control of these reproduction sites building upon previous observations, remarks about the genus and other species with similar patterns, and evidence of such aggression, although we did not directly observe any. Also, with the help of local wardens, we recorded vocalizations in mid-January, extending the previously reported reproductive period for this species. We therefore consider the conservation and restoration of rocky streams with adequate forest coverage to be an important conservation action for this species.

2008 ◽  
Vol 1 (1) ◽  
pp. 31-40 ◽  
Author(s):  
Edila Arnaud Ferreira Moura

This work presents the results of a study about the reproductive behavior of riverine women living in the Sustainable Development Reserve Amanã, in the Middle Solimões region, state of Amazonas. The study was done in 2001 with the objective of identify aspects of the reproductive behavior of 83 women, collected through reproductive history methodology. These women live in small localities along the rivers and lakes in the middle of the Amazonian forest. The study identified that these women initialize their reproductive period at the age of 17, in average, and the mean age of their last pregnancy occurs at the age of 42, considering those above 50 years old. 36% of these 83 women had lost one or more of their children before the age of five. Only 16% use contraceptives and 12% are sterilized. They don’t have access to the basic health assistance in a regular basis and the local midwives are extremely important in their assistance during pregnancy and delivery. This study em phasizes the importance of reproductive health programs including those social and cultural local conditions.


1991 ◽  
Vol 155 (5) ◽  
pp. 347-347 ◽  
Author(s):  
Raymond M Lowenthal ◽  
Jean B Panton ◽  
Margaret J Baikie ◽  
J Norelle Lickiss

Author(s):  
Robert F Engle ◽  
Martin Klint Hansen ◽  
Ahmet K Karagozoglu ◽  
Asger Lunde

Abstract Motivated by the recent availability of extensive electronic news databases and advent of new empirical methods, there has been renewed interest in investigating the impact of financial news on market outcomes for individual stocks. We develop the information processing hypothesis of return volatility to investigate the relation between firm-specific news and volatility. We propose a novel dynamic econometric specification and test it using time series regressions employing a machine learning model selection procedure. Our empirical results are based on a comprehensive dataset comprised of more than 3 million news items for a sample of 28 large U.S. companies. Our proposed econometric specification for firm-specific return volatility is a simple mixture model with two components: public information and private processing of public information. The public information processing component is defined by the contemporaneous relation with public information and volatility, while the private processing of public information component is specified as a general autoregressive process corresponding to the sequential price discovery mechanism of investors as additional information, previously not publicly available, is generated and incorporated into prices. Our results show that changes in return volatility are related to public information arrival and that including indicators of public information arrival explains on average 26% (9–65%) of changes in firm-specific return volatility.


Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 692
Author(s):  
Clara Calvo ◽  
Carlos Ivorra ◽  
Vicente Liern ◽  
Blanca Pérez-Gladish

Modern portfolio theory deals with the problem of selecting a portfolio of financial assets such that the expected return is maximized for a given level of risk. The forecast of the expected individual assets’ returns and risk is usually based on their historical returns. In this work, we consider a situation in which the investor has non-historical additional information that is used for the forecast of the expected returns. This implies that there is no obvious statistical risk measure any more, and it poses the problem of selecting an adequate set of diversification constraints to mitigate the risk of the selected portfolio without losing the value of the non-statistical information owned by the investor. To address this problem, we introduce an indicator, the historical reduction index, measuring the expected reduction of the expected return due to a given set of diversification constraints. We show that it can be used to grade the impact of each possible set of diversification constraints. Hence, the investor can choose from this gradation, the set better fitting his subjective risk-aversion level.


2020 ◽  
Vol 11 ◽  
Author(s):  
Kenichiro Imai ◽  
Kenta Nakai

At the time of translation, nascent proteins are thought to be sorted into their final subcellular localization sites, based on the part of their amino acid sequences (i.e., sorting or targeting signals). Thus, it is interesting to computationally recognize these signals from the amino acid sequences of any given proteins and to predict their final subcellular localization with such information, supplemented with additional information (e.g., k-mer frequency). This field has a long history and many prediction tools have been released. Even in this era of proteomic atlas at the single-cell level, researchers continue to develop new algorithms, aiming at accessing the impact of disease-causing mutations/cell type-specific alternative splicing, for example. In this article, we overview the entire field and discuss its future direction.


2005 ◽  
Vol 288 (4) ◽  
pp. L585-L595 ◽  
Author(s):  
Haifeng M. Wu ◽  
Ming Jin ◽  
Clay B. Marsh

Alveolar macrophages (AM) belong to a phenotype of macrophages with distinct biological functions and important pathophysiological roles in lung health and disease. The molecular details determining AM differentiation from blood monocytes and AM roles in lung homeostasis are largely unknown. With the use of different technological platforms, advances in the field of proteomics have made it possible to search for differences in protein expression between AM and their precursor monocytes. Proteome features of each cell type provide new clues into understanding mononuclear phagocyte biology. In-depth analyses using subproteomics and subcellular proteomics offer additional information by providing greater protein resolution and detection sensitivity. With the use of proteomic techniques, large-scale mapping of phosphorylation differences between the cell types have become possible. Furthermore, two-dimensional gel proteomics can detect germline protein variants and evaluate the impact of protein polymorphisms on an individual's susceptibility to disease. Finally, surface-enhanced laser desorption and ionization (SELDI) time-of-flight mass spectrometry offers an alternative method to recognizing differences in protein patterns between AM and monocytes or between AM under different pathological conditions. This review details the current status of this field and outlines future directions in functional proteomic analyses of AM and monocytes. Furthermore, this review presents viewpoints of integrating proteomics with translational topics in lung diseases to define the mechanisms of disease and to uncover new diagnostic and therapeutic targets.


Author(s):  
Anna Ferrante ◽  
James Boyd ◽  
Sean Randall ◽  
Adrian Brown ◽  
James Semmens

ABSTRACT ObjectivesRecord linkage is a powerful technique which transforms discrete episode data into longitudinal person-based records. These records enable the construction and analysis of complex pathways of health and disease progression, and service use. Achieving high linkage quality is essential for ensuring the quality and integrity of research based on linked data. The methods used to assess linkage quality will depend on the volume and characteristics of the datasets involved, the processes used for linkage and the additional information available for quality assessment. This paper proposes and evaluates two methods to routinely assess linkage quality. ApproachLinkage units currently use a range of methods to measure, monitor and improve linkage quality; however, no common approach or standards exist. There is an urgent need to develop “best practices” in evaluating, reporting and benchmarking linkage quality. In assessing linkage quality, of primary interest is in knowing the number of true matches and non-matches identified as links and non-links. Any misclassification of matches within these groups introduces linkage errors. We present efforts to develop sharable methods to measure linkage quality in Australia. This includes a sampling-based method to estimate both precision (accuracy) and recall (sensitivity) following record linkage and a benchmarking method - a transparent and transportable methodology to benchmark the quality of linkages across different operational environments. ResultsThe sampling-based method achieved estimates of linkage quality that were very close to actual linkage quality metrics. This method presents as a feasible means of accurately estimating matching quality and refining linkages in population level linkage studies. The benchmarking method provides a systematic approach to estimating linkage quality with a set of open and shareable datasets and a set of well-defined, established performance metrics. The method provides an opportunity to benchmark the linkage quality of different record linkage operations. Both methods have the potential to assess the inter-rater reliability of clerical reviews. ConclusionsBoth methods produce reliable estimates of linkage quality enabling the exchange of information within and between linkage communities. It is important that researchers can assess risk in studies using record linkage techniques. Understanding the impact of linkage quality on research outputs highlights a need for standard methods to routinely measure linkage quality. These two methods provide a good start to the quality process, but it is important to identify standards and good practices in all parts of the linkage process (pre-processing, standardising activities, linkage, grouping and extracting).


2020 ◽  
Vol 3 (3a) ◽  
Author(s):  
Lasmini

Corona virus or covid 19 is a dangerous virus that attacks the human respiratory system. Corona virus able to change the order of almost all of life’s joints in the world of education. In order to break the chain of the covid 19, goverments introduce a pattern of long range learning by means online learning. Application of this learning model certainly brings its own impact to students. The puspose of this study is to know the impact students are experiencing class 5 country primary school Pandawei during the online learning system. The method used was qualitative research methods with data collection techniques thrugh interviews and observations. The analysis technique used is qualitative descriptive. The main find of this research is increased students study habits using this online learning methods because the students are becoming accustomed  with technology so they’re easier discovering additional information about the lesson materials received search school.


2021 ◽  
Author(s):  
Hlib Nekrasov ◽  
Alexander Vostrikov ◽  
Ekaterina Prokofeva ◽  
Nashon Adero

Abstract Background: This article discusses the approach to the implementation of the project for the extraction and the methodology of preliminary processing of the obtained data with the aim of centralized accumulation for collective multipurpose use of the databank on the example of carbon dioxide emissions into the atmosphere by air transport for a given territory. It should be noted that on the basis of morphological analysis, processing, as well as the classification of spatial objects of the geodatabase and additional information, it is subsequently possible to organize, for example, a system of geoecological monitoring.Methods: At the fundamental level, the research used integration and process-based approaches, the method of extrapolation, expert methods of evaluation, random selection and analytical comparisons, a set of methods of spatial analysis based on various instruments and sources. In this study are used of open standards OGC, web, GIS technologies and the Internet for the formation, processing and storage of spatial data, their unambiguous geolocation, the implementation of territorial selections and visualization of results.Results: The set of data, which was organized according to the proposed and defined rules, made it possible to assess the structural processing of geospatial data, and to prepare a visual representation of the impact of aviation on the environmental situation over the designated geographic area.Conclusions: The transport industry was chosen as the object of research, but this solution can also be successfully applied to other logistics and industrial areas. During the implementation of the project, the analysis of the subject area was carried out, the architecture of the future prototype of the databank was designed, the accumulated data from the sources was structured, and a database was selected for storing them, taking into account the provision of high availability and ensuring stable operation under high loads. For the convenience of displaying data, an interactive visualization tool with a convenient and friendly user interface has been developed.


2021 ◽  
Author(s):  
Abdallah Aouadi ◽  
Farrah Samraoui ◽  
Laid Touati ◽  
Riad Nedjah ◽  
Lynda Souiki ◽  
...  

Abstract Investigating how Mediterranean wetlands respond to adjacent land use conversion, is an important first step in mitigating the impact of human encroachment and other environmental stressors. We monitored the composition and structure of waterbird assemblages, in a Mediterranean urban marsh, subjected to severe anthropogenic pressures. Remote sensing indicated that in the last two decades Boussedra Pond was subjected to landfill, resulting in a substantial reduction (~ 50%) of the marsh, while due to a lack of urban planning urban built-up and agriculture areas expanded considerably in its surroundings. Seasonal changes in the diversity of waterbirds, including the globally Endangered (EN) White-headed Duck Oxyura leucocephala and the Near-Threatened (NT) Ferruginous Duck Aythya nyroca, reflected the importance of the site as a staging and wintering area for many migratory species. The long-term study also suggested that breeding waterbirds species respond differentially to the loss and degradation of habitats, as highlighted by the resilience of the synanthropic Moorhen Gallinula chloropus and the disappearance of several breeding marsh specialists, like the Little Bittern Ixobrychus minutus and the Western Marsh Harrier Circus aeruginosus. The study points out the need for both a coordinated cross-sectorial land use planning and an immediate, affordable and sustainable wetland conservation action.


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