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In this case, a 43-year-old woman with a rare breast tumor and a history of augmentation mammoplasty is presented. The patient arrived at the clinic reporting a palpable lump in the rightmammary gland and two ipsilateral axillary nodes with pain on palpation. Mammography and ultrasound confirmed the presence of a 4 cmtumor and 2metastatic lymph nodes of 2 cm each, histopathological diagnosis was an encapsulated papillary cancer and two siliconomas, respectively. Interestingly, these nodes were able to take up technetium 99 and methylene blue contrast media. Due to these findings, adequate patient management was carried out with a skin-sparing mastectomy and hormonal treatment with tamoxifen. This report is relevant as it shows that axillary lymphadenopathy caused by silicone must be considered in the evaluation of a patient with a cancer diagnosis and history of augmentation mammoplasty, especially breast cancer as the node siliconomas present a high risk of being considered a false positive metastasis. [ABSTRACT FROM AUTHOR]

(1) Background: Hyperkalemia is a common finding in patients with heart failure and reduced ejection fraction (HFrEF), though its prognostic significance is controversial. There is no consensus on optimal potassium levels in these patients. The primary endpoint of this study was to determine the 5-year incidence of hyperkalemia in a cohort of patients with HFrEF. Secondary endpoints were to determine predictors of hyperkalemia and its impact on overall 5-year mortality; (2) Methods: retrospective, longitudinal, single-center observational study of patients with HFrEF followed-up in a specialized unit between 2011 and 2019. Hyperkalemia was considered as potassium concentration > 5.5 mEq/L; (3) Results: Hyperkalemia was observed in 170 (16.8%) of the 1013 patients. The 5-year hyperkalemia-free survival rate was 82.1%. Hyperkalemia was more frequent at the beginning of follow-up. Factors associated with hyperkalemia in the multivariate analysis were baseline potassium (HR 3.13, 95%CI 2.15–4.60; p < 0.001), creatinine clearance (HR 0.99, 95%CI 0.98–0.99; p = 0.013), right ventricular function (HR 0.95, 95%CI 0.91–0.99; p = 0.016) and diabetes mellitus (HR 1.40, 95%CI 1.01–1.96; p = 0.047). The overall survival rate at 5 years was 76.4%. Normal–high potassium levels (5–5.5 mEq/L) were inversely associated with mortality (HR 0.60, 95%CI 0.38–0.94; p = 0.025); (4) Conclusions: Hyperkalemia is a common finding in patients with HFrEF with an impact on the optimization of neurohormonal treatment. In our retrospective study, potassium levels in the normal–high range seem to be safe and are not associated with increased mortality. [ABSTRACT FROM AUTHOR]

The information fusion field has recently been attracting a lot of interest within the scientific community, as it provides, through the combination of different sources of heterogeneous information, a fuller and/or more precise understanding of the real world than can be gained considering the above sources separately. One of the fundamental aims of computer systems, and especially decision support systems, is to assure that the quality of the information they process is high. There are many different approaches for this purpose, including information fusion. Information fusion is currently one of the most promising methods. It is particularly useful under circumstances where quality might be compromised, for example, either intrinsically due to imperfect information (vagueness, uncertainty, ...) or because of limited resources (energy, time, ...). In response to this goal, a wide range of research has been undertaken over recent years. To date, the literature reviews in this field have focused on problem-specific issues and have been circumscribed to certain system types. Therefore, there is no holistic and systematic knowledge of the state of the art to help establish the steps to be taken in the future. In particular, aspects like what impact different information fusion methods have on information quality, how information quality is characterised, measured and evaluated in different application domains depending on the problem data type or whether fusion is designed as a flexible process capable of adapting to changing system circumstances and their intrinsically limited resources have not been addressed. This paper aims precisely to review the literature on research into the use of information fusion techniques specifically to improve information quality, analysing the above issues in order to identify a series of challenges and research directions, which are presented in this paper. [Display omitted] • High information quality levels are crucial in information systems. • Information fusion is a promising and active field for improving information quality. • There is no synthesised and organised knowledge of the state of the art in this field. • Key aspects such as information fusion techniques, information quality measurement and applicability require research. • We surveyed the literature, analysed major issues and listed a series of challenges and opportunities. [ABSTRACT FROM AUTHOR]

Wind and wave loads subject the tower structures of wind turbines to bending stress. The resulting initial linear strain gradients in the tower cross-section cause fatigue-induced degradation of the concrete at the outer edge of the structures. As the number of load cycles increases, stresses are gradually redistributed to the inner cross-section of the structure consequently. Most of the test results documented in the literature were obtained from small-scale concrete specimens or small-scale components. In those cases, the stiffness and stress redistributions occurring in the real component can only be insufficiently derived, and possible scale effects cannot be taken into account. Besides, available test results for individual component tests are mostly only for load cycles up to 2⋅106. However, significantly lower load levels and thus higher number of load cycles are expected to occur in wind turbines compared to usual fatigue tests. To deal with this issue, extensive fatigue tests on small cylindrical specimens as well as large-scale beams in the very-high-cycle fatigue range are carried out in this work. The test results of both cylindrical and beam specimens show the typical three-phase stiffness curves known from the literature. These curves exhibit a disproportionate decrease at the beginning of the loading, followed by a constant decrease in stiffness, and finally, a greater decrease in stiffness shortly before failure. Moreover, the stiffness curves from the tests on both specimen types show good agreement. It can be concluded that the results from small cylindrical specimen tests can be transferred to large-scale structural components. • Fatigue tests on large-scale concrete beams were carried out in a unique resonance-based testing facility. • Stiffness development of concrete cylinders and beam specimens was compared. • Good agreement between the stiffness behavior of both specimen types was found. • The stiffness behavior of cylindrical specimens can be transferred to large structures. [ABSTRACT FROM AUTHOR]

"Koinōnia and Justice. From Republic to Parmenides". The main reason why the developmental interpretation of the platonic Parmenides believes this dialogue constitutes a crisis in the development of Plato's thought is the idea that the philosopher criticizes therein its Theory of Ideas of the middle period - Phaedo, Symposium, Republic. The theory supposedly criticized would conceive the Ideas as absolutely simple and isolated unities that, as such, would make impossible the fulfilment of their own function. This would only be possible by a new relational conception of the Ideas introduced in Parmenides and developed in Sophist. In contrast to some scholars who do not even mention certain passages in those dialogues (e.g. Cordero, 2014, 2016), I will show 1) that the notion of koinōnia is essential to the project of the Republic, since its central idea, the notion of justice, is unthinkable without the notion of koinōnia of the Ideas with each other; and 2) that Parmenides makes use of this notion of justice (150a) precisely in relation to the eidetical koinōnia (143a-b) and to the Idea conceived as a whole (ὅλον) "which has come to be one complete/perfect thing out of all its parts - ἐξ ἁπάντων ἓν τέλειον γεγονός" (157e1, ἓν ἐκ πολλῶν, 157c6, ἓν τέλειον μόρια ἔχον, 157e4). [ABSTRACT FROM AUTHOR]

The Heston model (1993) is validated for MXN/USD options, calculating the difference between the theoretical premium and the one issued by the Mexican Derivatives Market. The parameters were estimated covering a period from 2003 to 2018 and the prices of the European Call and Put options were calculated, considering the exercise prices of November 9, 2018. The results reveal overvaluation of Call OTM and ITM options with a variation of 5.87% and 3.46%, respectively, and for Put OTM options with 11.41%, thus ratifying that the model is reliable, it is also confirmed that it is a hedging instrument for all those investors exposed to the exchange market risk. [ABSTRACT FROM AUTHOR]

This paper aims to combine the extreme value theory and CGARCH models to capture the long-term asymmetry effects and long memory in volatility and to improve the estimation of tail risk for Maya crude oil. The results of the backtesting confirm the forecasting ability of the symmetric and asymmetric CGARCH-EVT approaches for the estimation of dynamic VaR even though risk measures based on the GARCH-EVT family approaches provide also a better out of sample performance. The findings have important implications for crude oil market participants as they allow them to improve risk management and design optimal hedging strategies to reduce exposure to price risk of producers and consumers. [ABSTRACT FROM AUTHOR]

Non-destructive testing techniques, such as ultrasonic testing and acoustic emission analysis, commonly employ piezoelectric sensors for monitoring and detecting defects in structures. The quality of data acquired using these sensors is highly dependent on the coupling layer between the transducer and the structure's surface. In this context, this study compares the signal response of four different couplant materials, namely acrylic adhesive pads, honey, vaseline, and hot glue, applied to a steel surface. For this purpose, experiments were conducted using a laser Doppler vibrometer and acoustic emission analysis to investigate the signal transmission of the couplant materials and their impact on the signal response of a coupled piezoelectric sensor VS30-V. The repeatability of the experiments was statistically analyzed. The findings indicate that acoustic emission measurements with acrylic adhesive pads exhibited the lowest relative standard deviation of 11.4%, followed by honey (13.2%), hot glue (21.9%), and vaseline (32.1%). The investigated couplant materials exhibited different effects on the signal response of the piezoelectric sensor. Specifically, acrylic adhesive pads and hot glue demonstrated more reliable signal transmission in the frequency range of 50 kHz to 65 kHz. In contrast, honey and vaseline had better performance within the frequency range of 65 kHz and 80 kHz. Considering the frequency-dependent characteristics of signal transmission and the ease of application, acrylic adhesive pads and honey are considered the preferred couplant materials for the frequency ranges of 50 kHz to 65 kHz and 65 kHz to 80 kHz, respectively. • Analysis of frequency-dependent signal transmission of couplant materials. • Measurements involved laser Doppler vibrometer and acoustic emission techniques. • Relative standard deviation for statistical analysis of measurement repeatability. • Computation of transfer functions for couplant materials. [ABSTRACT FROM AUTHOR]

This paper tests the existence of financial contagion between US and Latin America stock markets based on the analysis of pattern of the correlation coefficients during crisis and stable periods. The study applies a dynamic conditional correlation multivariate GARCH model to estimate time-varying correlations and adopts the t-statistics test under a bootstrap procedure to examine the potential channels of financial contagion effects on emerging stock markets. The empirical results confirm that the estimated correlations has increased significantly in the period of financial turmoil as result of the presence of strong structural changes. Moreover, the study provides evidence that Brazil, Chile, Colombia Mexico and Peru stock markets are significantly affected by the contagion effects from the global financial crisis. However, Argentina stock market exhibits strong evidence of interdependence with the USA stock market. The findings have important implications for investors and policy makers, which seek preventive mechanisms to avoid negative effects of the financial contagion in emerging stock markets. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate whether carotid disease is associated with coronary artery disease (CAD) extension in patients undergoing treadmill exercise stress echocardiography (EE). Methods: We retrospectively studied 156 patients without previous vascular disease who underwent EE, carotid ultrasonography, and coronary angiography between 2002 and 2013. Low‐, intermediate‐, and high‐risk EE were defined as negative, localized ischemia, and multivessel/extensive ischemia EE respectively; carotid disease according to Mannheim and American Society of Echocardiography Consensus and CAD extension from zero to three vessel disease as stenosis ≥50% by visual assessment. Results: Of the 156 patients, 67 (42.9%), 43 (27.6%), 22 (14.1%), and 24 (15.4%) had zero, one, two, and three vessel disease respectively. Age (P = 0.047), male sex (P = 0.010), diabetes mellitus (P = 0.039), smoking habit (P = 0.015), fasting plasma glucose (P = 0.021), European Systematic COronary Risk Evaluation (P = 0.003), pretest CAD probability (P = 0.003), high‐risk EE (P < 0.001), and carotid plaque presence (CP) (P < 0.001) were associated in univariate analysis with more extensive CAD. Predictors of CAD extension in multivariate analysis were high‐risk EE (odds ratio [OR] 2.42, P < 0.001), CP presence (OR 1.75, P = 0.004), and pretest CAD probability >65% (OR 1.49, P = 0.023). CP was also associated with multivessel CAD in the 53 patients with low‐ or intermediate‐risk EE (P = 0.001). Conclusions: CP is associated with CAD extension in patients with ischemic heart disease suspicion undergoing EE. Patients with CP could benefit from a more aggressive therapeutic strategy regarding patients without carotid disease and similar risk EE, especially in intermediate‐ and/or low‐risk test where guidelines recommend initially optimal medical treatment. [ABSTRACT FROM AUTHOR]

The objective of this research is to evaluate the occupational risk due to thermal stress on workers in the incineration and drying processes at Arboriente S.A. The research characteristics consist of a field study, which is descriptive and quantitative. The population included twenty workers who perform the stated processes. For risk assessment, the Wet Bulb Globe Temperature Index (WBGT) was used. It is based on the characterization of the workstations, the measurement of the temperatures of Wet bulb, dry bulb and globe. In addition, the determination of the metabolic thermal load, and the calculation and evaluation of the index are also included. As a result, no hygienic risk was evidenced on any of the evaluated workstations attributable to thermal stress. This is mainly due to sufficient acclimatization of the workers and their low metabolic thermal load. [ABSTRACT FROM AUTHOR]

This paper sets out to use the bivariate VEC-EGARCH model with constant correlations to analyze the process by which the mean and volatility are transmitted between the crude futures markets and physical oil markets in Mexico. The results point to the existence of bilateral performance information transmission patterns with stronger effects from the futures markets to the physical markets, while the evidence for the effects of bilateral volatility transmission only exists between the oil futures and physical oil markets in Olmeca. The empirical findings are relevant to governmental authorities and consumers because they aid in designing cross-hedging strategies that mitigate exposure to the price risk in Mexican oil. [ABSTRACT FROM AUTHOR]

Augmentation mammoplasty is a very common surgery in our medium, with very well described complications. The acute hematoma after augmentation mammoplasty has a global incidence of 2-10%, however the subacute and late hematoma are rare, being the most common late complication the capsular contracture. We present a case of a 22 years old patient submitted to augmentation mammoplasty and who 19 days after surgery presented a hematoma following the autoinduction of vomiting to maintain her weight, whitout previous clinical background of bulimic. [ABSTRACT FROM AUTHOR]

This article propose apply a Virtual Classroom denominated LMS as a technological tool for transferring Knowledge to Workers of Plastigar company about processes and procedures industrial production plastic bags manufactured there. To carry out this proposal, was performed a research quantitative with descriptive analysis, applied to the problems exposed by the company Plastigar SAS on non-compliance of quality requirements and delivery times of orders, the result revealed the absence of a training plan given the logistics, the complexity required and the impact for the de laborization of employees. In the study the applicability of various technological tools against criteria of cost, type of learning, and self-know, required by Plastigar S.A.S was assessed.; As a result, it was concluded that the tool that best fits these characteristics and therefore is suggested is LMS (Learning Management System) a virtual classroom with content to facilitate understanding and memory of the production process without affecting the production line. [ABSTRACT FROM AUTHOR]

The study of learning to write at an early age has been the subject of much research in recent years. We now know that in languages of alphabetic writing like ours, learning to write requires both alphabetical knowledge and the awareness of the phonological structure of speech, with the development of spoken language a necessary skill for learning written language. However, few studies have been conducted in order to understand the link between these skills and the initial learning to write. The purpose of this study was to examine whether programs that integrate the promotion of oral language along with the development of phonological processing skills and alphabetical knowledge favour effectiveness of the written learning process. A quasi-experimental comparison group design with pre-test and post-test measures was used. The study involved 403 students from different public and private schools aged between 5 and 6. The results weigh the potential value of the program and support the development of teaching models that provide access to alphabetic knowledge from new educational perspectives that facilitate the learning of the writing system. [ABSTRACT FROM AUTHOR]

Actually, transmission and interconnection systems have several vulnerabilities including the facility to analyze traffic that allows a high rate of attacks own IPv4 protocol, therefore it is necessary for services such as FTP, DHCP and SSH seek Migration and Deployment to IPv6 networks. It has characteristics of computer security by IPSEC protocol, regardless of the free operating system or own end customers. This paper analyzes by testing the functionality of the standard settings or IPv6 protocol and its security features in the implementation and setting in a controlled environment to mitigate attacks on authentication, integrity and confidentiality of information, allowing to determine which scenario services analyzed guarantee a higher level of own native IPSEC reliability through regardless of the medium on which data travel. [ABSTRACT FROM AUTHOR]

Named Entity Recognition (NER) is a main task into Natural Language Processing. On the one hand, supporting the extraction of the information on unstructured data. On the other hand, The NER is a probabilistic graphical model that allows us to represent the conditional independency assumptions into the sequential labelling. In this paper, we propose a discriminative graphical model by using linear-chain Conditional Random Fields (CRFs). We present the experiments based on the Conll-2002 shared task and Ancora corpus according to the following criteria: recall, precision and F-score. Our contributions in this work are the following: first, we tested our baseline on the CoNLL-2002 shared task obtaining 80% F1-measure, and 59% F1-measure on AnCora corpus respectively. Finally, the application Vigtech allow us to identify information and patterns in the cancer topic, we discuss the results according to the model performance and the useful information to support the forecasting process [ABSTRACT FROM AUTHOR]

An analysis is made of the evolution of the Mexican peso exchange rate since 1954 in relation to the dollar, its volatility, and the use of financial derivatives during the different crisis that Mexico has suffered. During this period several different types of exchange rate have been used: fixed, dual, floating bands and free flotation, The authors arrive at the conclusion that the Mexican exchange rate is volatile, and that any external economic or financial occurrence affects the peso's value due to the Mexican economy's weakness. But the use of derivative instruments so as to protect it from exchange risks, help to consolidate the financial system and therefore results in a better economy for the country. [ABSTRACT FROM AUTHOR]

Abstract: Termination is one of the most interesting problems when dealing with context-sensitive rewrite systems. Although a good number of techniques for proving termination of context-sensitive rewriting (CSR) have been proposed so far, the adaptation to CSR of the dependency pair approach, one of the most powerful techniques for proving termination of rewriting, took some time and was possible only after introducing some new notions like collapsing dependency pairs, which are specific for CSR. In this paper, we develop the notion of context-sensitive dependency pair (CSDP) and show how to use CSDPs in proofs of termination of CSR. The implementation and practical use of the developed techniques yield a novel and powerful framework which improves the current state-of-the-art of methods for automatically proving termination of CSR. [Copyright &y& Elsevier]

Objectives: To ascertain where and how inhalers were removed after finalizing their use, and to determine how the information about recycling was received, as well as the importance of having reusable inhalers. Methods: Epidemiological, observational, cross-sectional and multicenter study performed in the community pharmacies of the Autonomous Community of Madrid, through the application of a voluntary and anonymous questionnaire that analyzed the knowledge and attitudes regarding the recycling of inhalers among adult users treated with inhalers. Results: From 22 community pharmacies, a total of 303 subjects (mean age 57.5±19.9 years; 46.70 men; mean time of inhalers' use 9.6±9.8 years; reason for use: asthma: 46.20, COPD: 25.70) were included. Overall, 66.20 and 67.50 of users gave a high importance to the recycling of inhalers and the availability of having a monthly rechargeable inhaler every 6 months, respectively. With regard to recycling, 42.90 of users recycled in the SIGRE point of the pharmacy. Only 330 of users had been informed about the place of delivering the inhaler, and in this context, in most cases this was performed by the pharmacist (76.30). Conclusions: Despite the majority of users consider that it is important the recycling of inhalers and the availability of re-usable inhalers, only one third refer having been informed about the place of delivering the inhaler. Information campaigns about the importance of recycling of inhalers and how to do it are warranted. In this setting, the community pharmacist could play a key role. [ABSTRACT FROM AUTHOR]

Background: Relationship between carotid and coronary artery disease (CAD) in patients undergoing invasive and non-invasive test is unclear. The aim of the study is to evaluate whether carotid disease is associated with CAD in patients submitted to exercise echocardiography (EE) and if it improves the EE ability to predict CAD.Methods: We retrospectively studied 156 subjects without previous vascular disease who underwent EE, carotid ultrasonography and coronary angiography between 2002 and 2013. Positive EE was defined as exercise induced wall motion abnormalities, carotid disease according to Manheim and American Society of Echocardiography Consensus and significant CAD as stenosis ≥50%.Results: Eighty-nine (57.1%) subjects had significant CAD. Factors associated with CAD in multivariate analysis were fasting plasma glucose (odds ratio [OR] 1.02, p = 0.031), pre-test probability of CAD > 65% (OR 3.71, p < 0.001), positive EE (OR 10.51, p < 0.001) and carotid plaque (CP) presence (OR 2.95, p = 0.013). There was neither statistical significant difference in area under the curve after addition of CP to EE results (0.77 versus 0.81, p = 0.525) nor sensitivity, specificity, predictive values or efficiency. CP presence reclassified as very high-risk according to Systematic COronary Risk Evaluation 13 patients (34.2%) with negative EE and 22 (33.3%) without CAD.Conclusion: CP is associated with CAD in patients undergoing EE, however its addition to EE does not improve CAD prediction, probably due to insufficient statistical power. CP reclassified one third of patients to very high-risk category despite negative EE or CAD absence, these subjects benefit from aggressive primary prevention interventions. [ABSTRACT FROM AUTHOR]

Different termination properties of conditional term rewriting systems have been recently described emphasizing the bidimensional nature of the termination behavior of conditional rewriting. The absence of infinite sequences of rewriting steps ( termination in the usual sense), provides the horizontal dimension. The absence of infinitely many attempts to launch the subsidiary processes that are required to check the rule's condition and perform a single rewriting step has been called V-termination and provides the vertical dimension. We have characterized these properties by means of appropriate notions of dependency pairs and dependency chains . In this paper we introduce a 2D Dependency Pair Framework for automatically proving and disproving all these termination properties. Our implementation of the framework as part of the termination tool mu-term and the benchmarks obtained so far suggest that the 2D Dependency Pair Framework is currently the most powerful technique for proving operational termination of conditional term rewriting systems. [ABSTRACT FROM AUTHOR]

An analysis is made of the evolution of the Mexican peso exchange rate since 1954 in relation to the dollar, its volatility, and the use of financial derivatives during the different crisis that Mexico has suffered. During this period several different types of exchange rate have been used: fixed, dual, floating bands and free flotation, The authors arrive at the conclusion that the Mexican exchange rate is volatile, and that any external economic or financial occurrence affects the peso's value due to the Mexican economy's weakness. But the use of derivative instruments so as to protect it from exchange risks, help to consolidate the financial system and therefore results in a better economy for the country. [ABSTRACT FROM AUTHOR]

The morphology and size of spermatozoa make it difficult to study the functional properties of the plasma membrane, however, some studies have revealed the presence of a number of ion channels in this cell. We measured the calcium (Ca++) influx induced by depolarization of the plasma membrane and by venom isolated from the Chilean black widow spider ( Latrodectus mactans), and functional changes in the presence of either high potassium or total venom. Our results indicate that the venom increased the Ca++ influx, with an EC50 of 6.1 μg/mL and triggering the acrosome reaction in 43.26% of the cells. The application of potassium (10 mM K+) or total venom (10 μg/mL) did not affect the morphology or DNA stability of the sperm. The effects induced by high K+ and venom suggest that direct blocking of K+ currents alters the passive properties of the plasma membrane, leading to the entry of Ca++. These results show the importance of functional changes induced by depolarizing the spermatozoa and by venom. This venom possesses one or more molecules that may be used as pharmacological tools for studies on spermatozoa and have potential applications in reproductive biotechnology. [ABSTRACT FROM AUTHOR]

Background context The most common adverse event after a lumbar puncture (LP) is a headache: In anaesthesiology, well studied is the protective effect of atraumatic spinal needles, and they are routinely used. However, this is less well known in diagnostic LP, and neurologists use atraumatic needles in less than 2% of times. Purpose The purpose of this study was to define the impact of needle type, atraumatic (Sprotte [S]) versus traumatic (Quincke [Q]) on postdural puncture headache (PDPH) incidence. Study design The study is based on a prospective, randomized, and simple-blinded clinical trial. Patient Sample Patients older than 14 years were scheduled for a diagnostic or therapeutic LP. Outcome Measures The outcome measure included the development of PDPH according to the International Headache Association criteria. Methods Patients fulfilling eligibility criteria were randomly allocated to one of two kinds of spinal needle: atraumatic or S-type or traumatic or Q-type. They were interviewed on days 2 and 7 about the development of PDPH. Results The incidence of PDPH was 22.43% with Q-type needle and 8.51% with S-type needle, p=.04. The duration of PDPH in patients in the S-type was 1 day or less, compared with a median of 4.14 days in the Q-type (p=.00). In the logistic regression model, the S-type needle together with the age of the patient were the only two statistically significant factors in the development of postlumbar puncture headache (PLPH), both of them being protective. Conclusions We found a lower incidence of PDPH with atraumatic needles, and it was statistically significant compared with the traumatic needles. Our study confirms the effectiveness of the atraumatic needles to prevent PDPH. [ABSTRACT FROM AUTHOR]

Abstract: The main objective was to study the effects, on sperm function, of the addition of two superoxide dismutase (SOD) analogues (Tempo and Tempol) to alpaca semen extender for cryopreservation. Twelve alpaca semen samples were collected using an artificial vagina and then diluted at a 1:3 ratio in an extender based on skim milk, egg yolk, and fructose. Each semen sample was divided into three equal parts to form the following groups: control, Tempo (1 mM), and Tempol (1 mM). Groups were cooled to 5 °C in 90 minutes (−1 °C in 3 minutes); when samples reached approximately 10 °C, SOD analogues were added to the respective groups. At 5 °C, ethylene glycol (final concentration, 0.1 M) was added to each group. After 30 minutes at 5 °C, samples were loaded in 0.25 mL plastic straws, placed in liquid nitrogen vapor for 15 minutes, and then plunged. Percentages of sperm motility, functional sperm membrane integrity, and viable sperm with intact acrosomes were evaluated before and after freeze-thaw using visual analysis, the hypoosmotic swelling test, and the double-stain trypan blue/giemsa technique, respectively. The Terminal deoxymucleotidyl transferase dUTP Nick End Labeling assay was performed for evaluation of sperm DNA fragmentation of frozen-thawed sperm. Sperm motility was higher (P < 0.05) in the Tempol and Tempo groups than in the control group (mean, 22.1%, 19.7%, and 11.2%, respectively), with similar results for functional sperm membrane integrity. Additionally, DNA fragmentation was lower (P < 0.05) in the Tempol group (16.7%) than in the control group (38.8%). Viable sperm with intact acrosomes were not affected by the use of SOD analogues. There was a negative correlation (r = −0.58) between DNA fragmentation of alpaca sperm and sperm motility after freeze-thawing, but DNA damage was neither related to functional membrane integrity nor viable sperm with intact acrosomes. We concluded that DNA fragmentation and loss of motility during cryopreservation of alpaca sperm could be partially prevented by supplementation of the semen extender with 1 mM Tempo or Tempol. [Copyright &y& Elsevier]

Since the 1970s, There have been studies of the venom of Latrodectus sp. spiders, in particular the latrotoxin (LTX) of Latrodectus mactans. Many of the studies were aimed at understanding the action of the venom on the muscular system. Now accepted that LTX is able to generate a calcium-permeable membrane pore and modulate the release of synaptic vesicles that activate a receptor and induce cellular changes. Interestingly, when work began with venom obtained from the Latrodectus sp present in Chile, it generated clinical indications similar to the bite of this spider in another country, with some differences in intensity. The purpose of the first studies was to understand the systemic mechanisms of this venom, and other active compounds were studied for biological interest. It was found that these molecules are capable of causing systemic effects such as changes in muscle contraction: of generating vascular relaxation and synaptic and cellular modulation; and of altering potassium conductance channels. Based on this evidence, we suggested biotechnological applications to characterize low molecular-weight compounds obtained from the Chilean Latrodectus venom and exploring the effects on the eleetrophysiology in oocytes and neurons, and the contraceptive effect on spermatozoa. [ABSTRACT FROM AUTHOR]

The morphology and size of spermatozoa hinder the study of the functional properties of the spermatozoa plasma membrane. However, some studies have revealed the presence of a number of ion channels in this cell. We set out to measure the endogenous currents and to study the effect of the venom of the Chilean black widow spider ( Latrodectus mactans). By patch-clamping bovine spermatozoa our results indicate the presence of an outwardly rectifying current, sensitive to changes in K+ concentration (30–140 mM) and to tetraethylammonium (TEA, 10–100 mM). The application of the venom (7.5 µg/ml) blocks these K+ currents and then alters the passive properties of the plasma membrane. This leads to the entry of Ca++, reflected by a change in basal fluorescent units (5±2 at 35±10 FAU). The Ca++ influx follows a reduction in the membrane conductance (control 22±2; venom 10±1 pS), as calcium channels open in accord with voltage dependence. [ABSTRACT FROM AUTHOR]

Coffee is characterized by presenting different maturation stages during harvest period, which confers a high grade of difficulty to the harvest mechanization task, being difficult to achieve a satisfactory level of selectivity (high content of mature-low content of inmature fruits within the harvested mass). Recent theoretical investigations carried out on the basis of mathematical modeling and CAD tool simulation of the coffee fruit-peduncle system, indicate that with the application of vibrational frequencies much higher to those historically used overseas (near of 20 Hz), can expect an important qualitative jump in the selectivity levels during mechanized coffee harvesting. The research was carried out in a laboratory using an experimental vibrational unit able to simulate the desired effects, achieving the excitation of isolates coffee branches (caturra variety) by shaking it in lateral and longitudinal directions, in a range of frequencies corresponding to a counter-phase vibrating mode of the fruit-peduncle system near to 200 Hz. Content of immature fruits in the harvested mass oscillated between 3,8 and 5,15 % for the varieties Yellow and Red Caturra respectively, being obtained 100 % of detachment of mature cherries for both varieties. [ABSTRACT FROM AUTHOR]