Depolarization of sperm membrane potential is a common feature of men with subfertility and is associated with low fertilization rate at IVF

STUDY QUESTION. Are significant abnormalities in outward (K+) conductance and resting membrane potential (Vm) present in the spermatozoa of patients undertaking IVF and ICSI and if so, what is their functional effect on fertilization success? SUMMARY ANSWER. Negligible outward conductance (≈5% of patients) or an enhanced inward conductance (≈4% of patients), both of which caused depolarization of Vm, were associated with a low rate of fertilization following IVF. WHAT IS KNOWN ALREADY. Sperm-specific potassium channel knockout mice are infertile with defects in sperm function, suggesting that these channels are essential for fertility. These observations suggest that malfunction of K+ channels in human spermatozoa might contribute significantly to the occurrence of subfertility in men. However, remarkably little is known of the nature of K+ channels in human spermatozoa or the incidence and functional consequences of K+ channel defects. STUDY DESIGN, SIZE AND DURATION. Spermatozoa were obtained from healthy volunteer research donors and subfertile IVF and ICSI patients attending a hospital assisted reproductive techniques clinic between May 2013 and December 2015. In total, 40 IVF patients, 41 ICSI patients and 26 normozoospermic donors took part in the study. PARTICIPANTS/MATERIALS, SETTING, METHODS. Samples were examined using electrophysiology (whole-cell patch clamping). Where abnormal electrophysiological characteristics were identified, spermatozoa were further examined for Ca2+ influx induced by progesterone and penetration into viscous media if sufficient sample was available. Full exome sequencing was performed to specifically evaluate potassium calcium-activated channel subfamily M α 1 (KCNMA1), potassium calcium-activated channel subfamily U member 1 (KCNU1) and leucine-rich repeat containing 52 (LRRC52) genes and others associated with K+ signalling. In IVF patients, comparison with fertilization rates was done to assess the functional significance of the electrophysiological abnormalities. MAIN RESULTS AND THE ROLE OF CHANCE. Patch clamp electrophysiology was used to assess outward (K+) conductance and resting membrane potential (Vm) and signalling/motility assays were used to assess functional characteristics of sperm from IVF and ICSI patient samples. The mean Vm and outward membrane conductance in sperm from IVF and ICSI patients were not significantly different from those of control (donor) sperm prepared under the same conditions, but variation between individuals was significantly greater (P< 0.02) with a large number of outliers (>25%). In particular, in ≈10% of patients (7/81), we observed either a negligible outward conductance (4 patients) or an enhanced inward current (3 patients), both of which caused depolarization of Vm. Analysis of clinical data from the IVF patients showed significant association of depolarized Vm (≥0 mV) with low fertilization rate (P= 0.012). Spermatozoa with electrophysiological abnormities (conductance and Vm) responded normally to progesterone with elevation of [Ca2+]i and penetration of viscous medium, indicating retention of cation channel of sperm (CatSper) channel function. LIMITATIONS, REASONS FOR CAUTION. For practical, technical, ethical and logistical reasons, we could not obtain sufficient additional semen samples from men with conductance abnormalities to establish the cause of the conductance defects. Full exome sequencing was only available in two men with conductance defects. WIDER IMPLICATIONS OF THE FINDINGS. These data add significantly to the understanding of the role of ion channels in human sperm function and its impact on male fertility. Impaired potassium channel conductance (Gm) and/or Vm regulation is both common and complex in human spermatozoa and importantly is associated with impaired fertilization capacity when the Vm of cells is completely depolarized

Wilson chains are not thermal reservoirs

Wilson chains, based on a logarithmic discretization of a continuous spectrum, are widely used to model an electronic (or bosonic) bath for Kondo spins and other quantum impurities within the numerical renormalization group method and other numerical approaches. In this short note we point out that Wilson chains can not serve as thermal reservoirs as their temperature changes by a number of order Delta E when a finite amount of energy Delta E is added. This proves that for a large class of non-equilibrium problems they cannot be used to predict the long-time behavior.Comment: 2 page

Desenvolvimento e Avaliação de um Software Educacional Avaliativo Jogo do Pirata

Este artigo tem como objetivo apresentar o desenvolvimento e a avaliação dosoftware educacional "Jogo do Pirata". Com o advento do computador atrelado a Webcomo parceiros na educação, necessita-se também de novas propostas avaliativas, o"Jogo do Pirata" é um instrumento de avaliação e se mostrou eficaz quando associado auma metodologia pedagógica simples, de cujo processo o aluno participa efetivamente

Food restriction in Nile tilapia juveniles (Oreochromis niloticus)

Aim of study: To evaluate if dietary restriction influence muscle and intestinal morphology as well as the production performance of juvenile Nile tilapia (Oreochromis niloticus).Area of study: State University of Western Paraná (Universidade Estadual do Oeste do Paraná – Unioeste), Toledo Campus, Brazil.Material and methods: The experimental design was completely randomized with four treatments and five replicates. The treatments were: 7:0 (fed daily; control); 6:1 (fed 6 consecutive days followed by 1 day of fasting); 5:2 (fed 5 consecutive days followed by 2 days of fasting); and 1:1 (fed 1 day followed by 1 day of fasting). A commercial ration with 33.70% crude protein and 4.60% lipid was used, and fish were fed four times daily until apparent satiety for 60 days.Main results: The following parameters were found to have differences among treatments (p<0.05): final weight, weight gain, final length, hepatosomatic index, visceral fat, intestinal quotient, protein efficiency rate, protein retention, ash, and frequency of muscle fiber diameters within the classes of<20 μm and between 20 and 50 μm. The intestinal villi height and hepatic glycogen content did not differ (p>0.05) among treatments. The cost of food and partial net revenue were higher in the 7:0 treatment compared to the experimental treatments.Research highlights: Dietary restriction for Nile tilapia in the juvenile phase negatively influences productive performance, centesimal composition, and muscle growth, which demonstrates that this practice is economically unfeasible for commercial production

Brief instrument for direct complex functionality assessment: a new ecological tool

BackgroundThe Direct Assessment of Functional Status (DAFS) is the only instrument validated in Brazil that assesses functionality directly with the patient. However, this clinical tool takes a long time to be administered. This limits its use in hospitals and outpatient clinics that require brief assessment instruments. Additionally, we need to count with a direct assessment because the number of older adults living alone is increasing and we thus lack reliable informants.ObjectiveThis study aimed to present the development and content validity evidence of a direct complex functionality test for older adults, the Brief Instrument for Direct Functionality Assessment (BIDFA).MethodA total sample of 30 older adults and eight expert judges took part in the study stages. The BIDFA construction stages were: (1) literature review of functionality instruments; (2) development of seven ecological tasks to evaluate the performance of daily complex activities with the older adults; (3) content analysis by eight expert judges; (4) pilot study with 30 older adults; (5) the ecological analysis of items; (6) focus group analysis; and (7) final version of the BIDFA.ResultsThe BIDFA had evidence of content validity with an agreement index of 96.5%. The final version of BIDFA was left with six domains of complex functionality divided into semantic memory and time orientation; shopping skills; executive attention, math and finance skills; organization; planning and procedural memory; and problem-solving. The complex functionality score by BIDFA ranges from 0 to 100 points.ConclusionThe BIDFA was found to have good content validity by the expert judges and by the ecological analysis of the items by the older adults. The new instrument is expected to help assess the functional status of older adults, in an abbreviated context including complex functionality demands, with a wider range of total and subdomain scores

On verbal agreement variation in European Portuguese: syntactic conditions for the 3SG/3PL alternation

In this paper we scrutinize a case of concord variation in European Portuguese (EP) concerning third plural vs. third singular verbal agreement in the co-presence of an overt plural argument, which in the standard variety agrees with the in! ected verb. " e paper is focused on the linguistic factors that correlate with singular concord in this context. Going beyond previous proposals that emphasize the correlation between agreement variation and particular morphological and phonological factors, it is shown that the incidence of non-standard singulars in EP may be straightforwardly explained within a syntactic account. " e empirical basis for this investigation is CORDIAL-SIN, a dialect corpus of EP (600,000 words). " e evidence from this corpus leads us to discuss and reconsider the role that di# erent linguistic factors play in the manifestation of non-standard singulars. It is shown that this case of third singular agreement occurs in the investigated EP varieties in correlation with particular syntactic conditions, mainly in unaccusative-like con- $gurations. Furthermore, it is suggested that this kind of agreement variation may be ultimately ascribed to lexical variation concerning the availability and feature speci$ cation of (null) expletives.info:eu-repo/semantics/publishedVersio

Determinação de ácidos orgânicos em plantas e alimentos da Amazônia. I - Ácidos orgânicos do Tucupi

Three types of Tucupi were analyzed by gas-Phase Chromatography. The following acids wore found: acetic, propionic, palmitic and oleic, in the yellow, white and macaxeira types; butiric and valeric in yellow type; and succinic in the yellow and white types.Três tipos de Tucupi foram analisados por Cromatografia em fase gasosa. Constatou-se a presença dos ácidosacético, propiônico, palmítico e oléico nos tipos amarelo, branco e de macaxeira; dos ácidos butírico e valérico no tipo amarelo, enquanto que o ácido succínico foi detectado nos tipos amarelo e branco

Cluster headache and intracranial aneurysm

In the present study we describe the cases of two patients with cluster-like headache related to intracranial carotid artery aneurysm. One of these patients responded to verapamil prescription with headache resolution. In both cases the surgical clipping of the aneurysm resolved the cluster pain. These findings strongly suggest a pathophysiological link between the two conditions. The authors discuss the potential pathophysiological mechanisms underlying cluster-like headache due to intracranial carotid artery aneurysm