Elucidating lipid conformations in the ripple phase: Machine learning reveals four lipid populations.

A new mixed radial-angular, three-particle correlation function method in combination with unsupervised machine learning was applied to examine the emergence of the ripple phase in dipalmitoylphosphatidylcholine (DPPC) lipid bilayers using data from atomistic molecular dynamics simulations of system sizes ranging from 128 to 4096 lipids. Based on the acyl tail conformations, the analysis revealed the presence of four distinct conformational populations of lipids in the ripple phases of the DPPC lipid bilayers. The expected gel-like (ordered; Lo) and fluid-like (disordered; Ld) lipids are found along with their splayed tail equivalents (Lo,s and Ld,s). These lipids differ, based on their gauche distribution and tail packing. The disordered (Ld) and disordered-splayed (Ld,s) lipids spatially cluster in the ripple in the groove side, that is, in an asymmetric manner across the bilayer leaflets. The ripple phase does not contain large numbers of Ld lipids; instead they only exist on the interface of the groove side of the undulation. The bulk of the groove side is a complex coexistence of Lo,Lo,s, and Ld,s lipids. The convex side of the undulation contains predominantly Lo lipids. Thus, the structure of the ripple phase is neither a simple coexistence of ordered and disordered lipids nor a coexistence of ordered interdigitating gel-like (Lo) and ordered-splayed (Lo,s) lipids, but instead a coexistence of an ordered phase and a complex mixed phase. Principal component analysis further confirmed the existence of the four lipid groups.

Xenon and Krypton Dissolved in Water Form Nanoblobs: No Evidence for Nanobubbles.

We demonstrate, experimentally and by molecular dynamics simulations, that krypton and xenon form nanostructured water-gas domains. High pressure was applied to force the inert gases to dissolve in water following Henry's law, then the liquid was depressurized, centrifuged, and inspected by dynamic light scattering. The observed objects have similar sizes and electrical properties to nanobubbles, but we found that they have fairly neutral buoyancy even at high gravitational fields. We posit that the formed nano objects are not bubbles but blobs, unique structures conceived as clathrate-hydrate precursors, thus resolving the so-called Laplace pressure bubble catastrophe.

Effects of progestogens used in menopause hormone therapy on the normal breast and benign breast disease in postmenopausal women.

Hormone replacement therapy in menopause is used to improve climacteric syndrome in women whose quality of life is affected. However, given the wide variety of progestogens available, it is important to evaluate their differential benign changes (radiological, cellular, and clinical) on the breast. This review aimed to determine the different benign changes of progestogens used in postmenopausal combined hormone therapy on the breast (radiological, cellular, and clinical), in women without mammary pathology, in order to establish their safety profile. A systematic review of the literature was carried out with a balanced search strategy for the identification of relevant references in the MEDLINE, BVSalud, EMBASE, ProQuest, and Cochrane databases until November 2019. The search terms used were 'menopause' or 'hormonal replacement therapy' or 'progestins' or 'estrogen' or 'mastodynia' or 'benign breast disease' or 'mammography'. Data were collected from the 'eligible' articles by two researchers (ARF and SHA), and possible discrepancies in inclusion were resolved by consensus. A total of 1886 articles were identified; 60 full-text articles were reviewed, and 17 articles that met the inclusion criteria were included for the qualitative analysis. In conclusion, combined hormone replacement therapy is associated with benign effects on the breast, such as mastodynia and increased mammographic density.

Derivation of multivariate indices of milk composition, coagulation properties, and curd yield in Manchega dairy sheep.

This study approaches the interrelation patterns between composition of milk and whey, curd yield, chromaticity, syneresis, and technological quality of Manchega sheep milk using multivariate factor analysis. In addition, the effect of the main husbandry components (flock, prolificacy, season of the year, stage of lactation, and parity) on the common latent factors that define the pattern of variation of Manchega milk was assessed. For this purpose, 1,200 individual Manchega ewe milk samples from 4 different flocks registered under the Protected Designation of Origin Queso Manchego were analyzed (50 ewes/flock). Samples were collected in 2 different seasons of the year (spring and autumn) and at 3 time points per season: early, mid-, and late lactation. The obtained results suggested that curd yield mainly depends on milk composition, and the retention of water in the curd is related to coagulation traits. Thus, composition and moisture content could be useful indicators to assess the efficiency and quality of milk intended for cheesemaking, regardless of the analysis of coagulation properties. Finally, in terms of husbandry, a direct effect of flock and stage of lactation was observed on all analyzed factors, with a lower influence of season and parity.

Eco-efficiency evaluation in wastewater treatment plants considering greenhouse gas emissions through the data envelopment analysis-tolerance model.

The eco-efficiency evaluation in wastewater treatment plants (WWTPs) is used to know and improve the environmental and economic efficiency of these processes, systems, products, and services. The eco-efficiency evaluations in WWTP contemplate the inputs to be minimized, the desirable results to be maximized, and the undesired results to be minimized. Data envelopment analysis (DEA) is a widely used method to evaluate the eco-efficiency of WWTPs; integrating several approaches in a single index, traditional DEA models do not take into account the uncertainty in the data. This study evaluates the eco-efficiency of a sample of Catalan WWTPs, considering the uncertainty of the data (DEA tolerance model), and it is for the first time that together with CO2, other greenhouse gas (GHG) such as CH4 and N2O are considered as part of the process outputs. GHG emissions were quantified using methods reported in the literature. Seven hundred twenty-nine eco-efficiency scores were estimated for each WWTP instead of a single score like conventional DEA models, analyzing optimistic and pessimistic scenarios. The WWTPs were classified according to the estimated eco-efficiency scores, accounting for the uncertainty in each of the scenarios, and demonstrating the changes in the performance of the WWTPs in the different scenarios. Only two WWTPs were eco-efficient in all the scenarios evaluated. This approach provides essential information to improve efficiency and innovation in the wastewater sector.

Helminth Fauna of Scomberomorus Sierra (Actinopterygii: Scombridae) in Southeastern Gulf of California, Mexico.

From January to May 2015, a sample of 50 individuals of the Pacific sierra Scomberomorus sierra Jordan and Starks, 1895 captured off Mazatlán (southeastern Gulf of California, Mexico) were reviewed for helminths. A total of 6, 255 parasitic worms belonging to 11 species (9 in adult stage and 2 larvae) were obtained. Trematoda was the best represented group with 6 species of Didymozoidae Monticelli, 1888 and 1 of Bucephalidae Poche, 1907. In addition, 2 monogenean species and 2 of Nematoda were collected. In this study, the first molecular sequences for didymozoid species in Mexico were generated, and for Glomeritrema sp. at worldwide level. The most prevalent species were Didymocylindrus sp. (92 %) and Didymocystis scomberomori (MacCallum & MacCallum, 1916) (88 %), whereas the monogenean Thoracocotyle crocea MacCallum, 1913 reached the highest value of mean intensity (75.2). The coincidence between the helminthological composition established in our study and that reported for the same scombrid in 4 localities from the Mexican South Pacific (sharing 10 species) suggests that this group of species persistently parasitize S. sierra throughout its distribution along the Mexican Pacific coast; furthermore, due to the richness of didymozoids and the affinity of Thoracocotylidae species for S. sierra, both groups can be considered typical parasites of this fi sh.

Absence of Magnetic Proximity Effect at the Interface of Bi_{2}Se_{3} and (Bi,Sb)_{2}Te_{3} with EuS.

We performed x-ray magnetic circular dichroism (XMCD) measurements on heterostructures comprising topological insulators (TIs) of the (Bi,Sb)_{2}(Se,Te)_{3} family and the magnetic insulator EuS. XMCD measurements allow us to investigate element-selective magnetic proximity effects at the very TI/EuS interface. A systematic analysis reveals that there is neither significant induced magnetism within the TI nor an enhancement of the Eu magnetic moment at such interface. The induced magnetic moments in Bi, Sb, Te, and Se sites are lower than the estimated detection limit of the XMCD measurements of ∼10^{-3} µ_{B}/at.

Cholesterol sequestration by xenon nano bubbles leads to lipid raft destabilization.

Combined coarse-grained (CG) and atomistic molecular dynamics (MD) simulations were performed to study the interactions of xenon with model lipid rafts consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) and cholesterol (Chol). At a concentration of 2 Xe/lipid we observed an unexpected result: spontaneous nucleation of Xe nano bubbles which rapidly plunged into the bilayer. In this process Chol, essential for raft stabilization, was pulled out from the raft into the hydrophobic zone. When concentration was further increased (3 Xe/lipid), the bubbles increase in size and disrupted both the membrane and raft. We computed the radial distribution functions, pair-wise potentials, second virial coefficients and Schlitter entropy to scrutinize the nature of the interactions. Our findings, concurring with a recent report on the origin of general anaesthesia (M. A. Pavel, E. N. Petersen, H. Wang, R. A. Lerner and S. B. Hansen, Proc. Natl. Acad. Sci. U. S. A., 2020, 117(24), 13757-13766), suggest that the well-known anaesthetic effect of Xe could be mediated by sequestration of Chol, which, in turn, compromises the stability of rafts where specialized proteins needed to produce the nervous signal are anchored.

Using multivariate analysis to explore the relationships between color, composition, hygienic quality, and coagulation of milk from Manchega sheep.

This study explores the relationships between composition, hygienic quality, and color values of milk to evaluate whether colorimetry could be used as a valid predictor of the quality of raw milk and its coagulation. For this purpose, we performed analyses in 1,200 individual samples of Manchega sheep milk from 4 flocks from the region of Castilla-La Mancha, Spain. Based on the measured variables, we determined the differences and similarities between coagulating and noncoagulating samples using discriminant analysis techniques. The variables with a higher discriminant ability were lactose content, somatic cell score, pH, and the color values lightness (L*) and red/green value (a*). The model based on color values showed a predictive ability similar to that found in the model based on milk composition and hygienic quality. Canonical correlation analysis allowed us to explore the relationships between both sets of variables. Canonical correlations for the first and second pair of canonical values were 0.794 and 0.438, respectively. Both values were significant and represented 92.82% of the observed variability. The correlation structure showed that color values had a strong correlation with fat and protein content and with total solids, and they had a weak correlation with lactose content and somatic cell score. The 2 first combinations of standardized canonical variability could be considered a predictable measure of the composition and, to a lesser extent, the hygiene of milk. Measurement of color values could be a rapid and effective means of supplementing standard analyses when determining the coagulation ability of Manchega sheep milk.

Temperature-independent genome-wide DNA methylation profile in turbot post-embryonic development.

The morphological and biological characteristics of ectothermic vertebrates are known to be strongly influenced by environmental conditions, particularly temperature. Epigenetic mechanisms such as DNA methylation have been reported to contribute to the phenotypic plasticity observed in vertebrates in response to environmental changes. Additionally, DNA methylation is a dynamic process that occurs throughout vertebrate ontogeny and it has been associated with the activation and silencing of gene expression during post-embryonic development and metamorphosis. In this study, we investigated genome-wide DNA methylation profiles during turbot metamorphosis, as well as the epigenetic effects of temperature on turbot post-embryonic development. Fish growth and rates of development were greatly affected by rearing temperature. Thus, turbot raised at ambient temperature (18 °C) achieved greater body weights and progressed through development more quickly than those reared at a colder temperature (14 °C). Genome-wide DNA methylation dynamics analyzed via a methylation-sensitive amplified polymorphism (MSAP) technique were not significantly different between animals reared within the two different thermal environments. Furthermore, comparisons between phenotypically similar fish revealed that genome-wide DNA methylation profiles do not necessarily correlate with specific developmental stages in turbot.

Population data for 21 autosomal STR loci (GlobalFiler kit) in two Mexican-Mestizo population from the northwest, Mexico.

Mexican Mestizos (admixed) have been poorly studied for short tandem repeats (STRs) included for new human identification (HID) kits, such as the GlobalFiler PCR Amplification kit. Therefore, this kit was analyzed in 784 unrelated volunteers from the city of Tijuana (n = 381) and Sonora state (n = 403) in the northwest region of Mexico. Allele frequencies, forensic parameters, Hardy-Weinberg equilibrium, and linkage equilibrium were estimated or evaluated for 21 autosomal STRs, respectively. For this HID kit, the combined power of discrimination (PD) was > 0.99999999999999 (RMP range = 1.23 to 3.0 × 10-25), and the combined power of exclusion (PE) were 0.999999993 and 0.999999997 in Tijuana city and Sonora state, respectively. Interpopulation analyses based on STRs of the GlobalFiler kit was performed, including four Mexican Native American, one Mexican Mestizo, and four ethnic American populations (USA), previously studied. The low-but significant-differentiation observed among Mexican Mestizos (FST = 0.0969%; p = 0.02584) justifies the creation of STR databases for HID purposes in this country. In brief, results allow the confident use of the GlobalFiler kit for HID purposes in Mestizo population from the Northwest region Mexico.

Multivariate analysis of the milk coagulation process in ovine breeds from Spain.

In Spain, ewe milk is mainly used for cheesemaking, and farming systems have traditionally been based on the use of autochthonous breeds. However, in recent years, the progressive introduction of highly productive foreign breeds in Spanish farms has led to an increasing interest in the characterization of dairy sheep breeds to evaluate whether genetic selection schemes should focus on productivity or milk technological aptitude. The purpose of this work was to explore milk composition and coagulation to classify 4 of the main dairy sheep breeds used in Spain. This study included 832 individual ewe milk samples from the breeds Manchega, Assaf, Merino de Grazalema, and Merino de Los Pedroches. Samples were analyzed for native pH, composition (fat, protein, lactose, and total solids), coagulation properties, and individual laboratory curd yield. An indicator of coagulation efficiency was also determined. Canonical discriminant analysis was performed to establish differences and similarities among breeds based on the measured variables. In addition, cluster analysis was performed to study and quantify the concrete relationships among the discriminated groups. Discriminant analysis proved to be a powerful tool to accurately draw distinctions between breeds. In all cases, discrimination among breeds was evident and the 4 breeds could be easily differentiated. Cluster analysis showed greater similarity between Merino de Grazalema and Assaf compared with the other breeds, and F-statistics indicated a higher discriminating ability for the variables related to milk composition. However, Merino de Grazalema and Manchega were difficult to separate according to milk composition, but the coagulation process differenced them clearly. Coagulation also evidenced similarities between Manchega and Merino de Los Pedroches, although the latter was revealed to be the most different breed of all 4, which could lay the ground for its differentiation as an independent breed in the Official Catalogue of Spanish Livestock Breeds.

Tziminema unachi n. gen., n. sp. (Nematoda: Strongylidae: Strongylinae) parasite of Baird's tapir Tapirus bairdii from Mexico.

A new genus and species of nematode, Tziminema unachi n. gen., n. sp. is described from the caecum and colon of Baird's tapir Tapirus bairdii (Gill, 1865), found dead in the Reserva de la Biósfera El Triunfo, Chiapas State, in the Neotropical realm of Mexico. Tziminema n. gen. differs from the other nine genera included in the Strongylinae by two main characteristics: having 7-9 posteriorly directed tooth-like structures at the anterior end of the buccal capsule, and the external surface of the buccal capsule being heavily striated. Phylogenetic analyses of the DNA sequences of the mitochondrial cytochrome c oxidase and nuclear DNA, including a partial sequence of the internal transcribed spacer 1, 5.8S and a partial sequence of the internal transcribed spacer 2 of the new taxon, confirmed its inclusion in Strongylinae and its rank as a new genus.

Metal Insertion in a Methylamine-Functionalized Zirconium Metal-Organic Framework for Enhanced Carbon Dioxide Capture.

The reaction of ZrCl4 with 2',3',5',6'-tetramethylamino-p-terphenyl-4,4″-dicarboxylic acid (H2tpdc-4CH2NH2·3HCl) in the presence of NaF affords Zr6O4(OH)2.1F1.9(tpdc-4CH2NH2·3HCl)6 (1), which is a new member of the Zr6O4(OH)4(dicarboxylate linker)12 or UiO-68 family, and exhibits high porosity with BET and Langmuir surface areas of 1910 m2/g and 2220 m2/g, respectively. Remarkably, fluoride ion incorporation in the zirconium clusters results in increased thermal stability, marking the first example of enhancement in the stability of a UiO framework by this defect-restoration approach. Although material 1 features four alkylamine groups on each organic linker, the framework does not exhibit the high CO2 uptake that would be expected for reaction between CO2 and the amine groups to form carbamic acid or ammonium carbamate species. The absence of strong CO2 adsorption can likely be attributed to protonation at some of the amine sites and the presence of counterions. Indeed, exposure of material 1 to acetonitrile solutions of the organic bases 1,8-bis(dimethylamino)naphthalene (DMAN) or trimethylamine, affords a partially deprotonated material, which exhibits enhanced CO2 uptake. Exposure of basic amine sites also facilitates the postsynthetic chelation of copper(I) ([Cu(MeCN)4]·CF3SO3) to yield material 2 with an enhanced CO2 uptake of 4 wt % at 0.15 bar, which is double that of the parent framework 1.

Bovine leukaemia virus DNA in fresh milk and raw beef for human consumption.

Bovine leukaemia virus (BLV) is the causative agent of enzootic bovine leucosis, which has been reported worldwide. BLV has been found recently in human tissue and it could have a significant impact on human health. A possible hypothesis regarding viral entry to humans is through the consumption of infected foodstuffs. This study was aimed at detecting the presence of BLV DNA in raw beef and fresh milk for human consumption. Nested PCR directed at the BLV gag gene (272 bp) was used as a diagnostic test. PCR products were confirmed by Sanger sequencing. Forty-nine per cent of the samples proved positive for the presence of proviral DNA. This is the first study highlighting the presence of the BLV gag gene in meat products for human consumption and confirms the presence of the viral DNA in raw milk, as in previous reports. The presence of viral DNA in food products could suggest that viral particles may also be found. Further studies are needed to confirm the presence of infected viral particles, even though the present findings could represent a first approach to BLV transmission to humans through foodstuff consumption.

Anisotropic Absorption of Pure Spin Currents.

Spin transfer in magnetic multilayers offers the possibility of ultrafast, low-power device operation. We report a study of spin pumping in spin valves, demonstrating that a strong anisotropy of spin pumping from the source layer can be induced by an angular dependence of the total Gilbert damping parameter, α, in the spin sink layer. Using lab- and synchrotron-based ferromagnetic resonance, we show that an in-plane variation of damping in a crystalline Co_{50}Fe_{50} layer leads to an anisotropic α in a polycrystalline Ni_{81}Fe_{19} layer. This anisotropy is suppressed above the spin diffusion length in Cr, which is found to be 8 nm, and is independent of static exchange coupling in the spin valve. These results offer a valuable insight into the transmission and absorption of spin currents, and a mechanism by which enhanced spin torques and angular control may be realized for next-generation spintronic devices.

Acute effects of simultaneous electromyostimulation and vibration on leg blood flow in spinal cord injury.

STUDY DESIGN: Randomized crossover. OBJECTIVES: To analyze the acute effects of isolated and simultaneous application of whole-body vibration (WBV) and electromyostimulation (ES) on popliteal artery blood velocity (BV) and skin temperature (ST) of the calf in subjects with spinal cord injury (SCI). SETTING: Valladolid, Spain. METHODS: Ten subjects with SCI were assessed in five different sessions. After a familiarization session, four interventions were applied in random order; WBV, ES, simultaneous WBV and ES (WBV+ES), and 30 s of WBV followed by 30 s of ES (WBV30/ES30). Each intervention consisted of 10 sets × 1 min ON+1 min OFF. Subjects were seated on their own wheelchairs with their feet on the vibration platform (10 Hz, 5 mm peak-to-peak), and ES was applied on the gastrocnemius muscle of both legs (8 Hz, 400 µs). RESULTS: The simultaneous application (WBV+ES) produced the greatest increase in mean BV (MBV; 36% and 42%, respectively) and peak BV (PBV; 30% and 36%, respectively) during the intervention. This intervention produced the greatest mean increases in MBV (21%) and PBV (19%) during the recovery period. Last, this intervention produced the highest increase in ST during the intervention (2.1 °C). CONCLUSION: The simultaneous application of WBV+ES seems to produce a greater increase in MBV and PBV of the popliteal artery and ST of the calf than the isolated (WBV or ES) or consecutive application of both stimuli (WBV30/ES30). This study provides an efficient therapeutic methodology to improve peripheral arterial properties, which is pivotal in SCI patient's rehabilitation.

Chronic effects of simultaneous electromyostimulation and vibration on leg blood flow in spinal cord injury.

STUDY DESIGN: Randomized two-group parallel. OBJECTIVES: The objective of this study was to analyze the adaptations on the popliteal artery (mean blood velocity (MBV), peak blood velocity (PBV), arterial resting diameter (RD) and blood flow (BF)) induced by 12 weeks of simultaneous application of whole-body vibration and electromyostimulation (WBV+ES) in patients with spinal cord injury (SCI). Secondarily, the musculoskeletal effects of this therapy on the gastrocnemius muscle thickness (MT) and femoral neck bone mineral density (BMD) were analyzed. SETTING: Valladolid, Spain. METHODS: Seventeen SCI patients (American Spinal Injury Association (ASIA) A or B) were randomly assigned to the experimental group (EG=9) or the control group (CG=8). Each subject was assessed in four different occasions: at baseline, after 6 weeks (Post-6) and 12 weeks of the treatment (Post-12) and 8 weeks after the end of the treatment (Post-20). Subjects in the EG performed 30 10-min sessions of WBV+ES during 12 weeks. RESULTS: In the EG, RD increased compared with the baseline value at Post-6 (9.5%, P<0.01), Post-12 (19.0%, P<0.001) and Post-20 (16.7%, P<0.001). Similarly, in the EG, BF increased compared with the baseline value and with CG only at Post-12 ((33.9%, P<0.01) and (72.5%, P<0.05), respectively). Similarly, WBV+ES increased the MT of the gastrocnemius. BMD of both hips remained invariable during the study. CG showed no change at any point. CONCLUSIONS: WBV+ES improved popliteal artery BF, RD and MT after 12 weeks in SCI patients. This increase in RD remained above baseline after 8 weeks. The combination of WBV and ES could be considered a promising alternative to reverse the musculoskeletal atrophy and improve peripheral vascular properties in SCI patients.

Population structure and effective/census population size ratio in threatened three-spined stickleback populations from an isolated river basin in northwest Spain.

Variability at 20 microsatellite loci was examined to assess the population genetic structure, gene flow, and effective population size (N(e)) in three populations of three-spined stickleback (Gasterosteus aculeatus) from the upper basin of the Miño River in Galicia, NW Spain, where this species is threatened. The three populations showed similar levels of genetic diversity. There is a significant genetic differentiation between the three populations, but also significant gene flow. N(e) estimates based on linkage disequilibrium yielded values of 355 for the Miño River population and 241 and 311 for the Rato and Guisande Rivers, respectively, although we expect that these are overestimates. N(e) estimates based on temporal methods, considering gene flow or not, for the tributaries yielded values of 30-56 and 47-56 for the Rato and Guisande Rivers, respectively. Estimated census size (N(c)) for the Rato River was 880 individuals. This yielded a N(e)/N(c) estimate of 3-6 % for temporal estimation of N(e), which is within the empirical range observed in freshwater fishes. We suggest that the three populations analyzed have a sufficient level of genetic diversity with some genetic structure. Additionally, the absence of physical barriers suggests that conservation efforts and monitoring should focus in the whole basin as a unit.

Genome-wide methylation study of diploid and triploid brown trout (Salmo trutta L.).

The induction of triploidization in fish is a very common practice in aquaculture. Although triploidization has been applied successfully in many salmonid species, little is known about the epigenetic mechanisms implicated in the maintenance of the normal functions of the new polyploid genome. By means of methylation-sensitive amplified polymorphism (MSAP) techniques, genome-wide methylation changes associated with triploidization were assessed in DNA samples obtained from diploid and triploid siblings of brown trout (Salmo trutta). Simple comparative body measurements showed that the triploid trout used in the study were statistically bigger, however, not heavier than their diploid counterparts. The statistical analysis of the MSAP data showed no significant differences between diploid and triploid brown trout in respect to brain, gill, heart, liver, kidney or muscle samples. Nonetheless, local analysis pointed to the possibility of differences in connection with concrete loci. This is the first study that has investigated DNA methylation alterations associated with triploidization in brown trout. Our results set the basis for new studies to be undertaken and provide a new approach concerning triploidization effects of the salmonid genome while also contributing to the better understanding of the genome-wide methylation processes.