Opposite Faces Research Articles

Recombinant Lectin from Tepary Bean (Phaseolus acutifolius) with Specific Recognition for Cancer-Associated Glycans: Production, Structural Characterization, and Target Identification.

Herein, we report the production of a recombinant Tepary bean lectin (rTBL-1), its three-dimensional (3D) structure, and its differential recognition for cancer-type glycoconjugates. rTBL-1 was expressed in Pichia pastoris, yielding 316 mg per liter of culture, and was purified by nickel affinity chromatography. Characterization of the protein showed that rTBL-1 is a stable 120 kDa homo-tetramer folded as a canonical leguminous lectin with two divalent cations (Ca2+ and Mn2+) attached to each subunit, confirmed in its 3D structure solved by X-ray diffraction at 1.9 Å resolution. Monomers also presented a ~2.5 kDa N-linked glycan located on the opposite face of the binding pocket. It does not participate in carbohydrate recognition but contributes to the stabilization of the interfaces between protomers. Screening for potential rTBL-1 targets by glycan array identified 14 positive binders, all of which correspond to β1-6 branched N-glycans’ characteristics of cancer cells. The presence of α1-6 core fucose, also tumor-associated, improved carbohydrate recognition. rTBL-1 affinity for a broad spectrum of mono- and disaccharides was evaluated by isothermal titration calorimetry (ITC); however, no interaction was detected, corroborating that carbohydrate recognition is highly specific and requires larger ligands for binding. This would explain the differential recognition between healthy and cancer cells by Tepary bean lectins.

Female horses spontaneously identify a photograph of their keeper, last seen six months previously

Horses are capable of identifying individual conspecifics based on olfactory, auditory or visual cues. However, this raises the questions of their ability to recognize human beings and on the basis of what cues. This study investigated whether horses could differentiate between a familiar and unfamiliar human from photographs of faces. Eleven horses were trained on a discrimination task using a computer-controlled screen, on which two photographs were presented simultaneously (32 trials/session): touching one was rewarded (S+) and the other not (S−). In the training phase, the S+ faces were of four unfamiliar people which gradually became familiar over the trials. The S− faces were novel for each trial. After the training phase, the faces of the horses’ keepers were presented opposite novel faces to test whether the horses could identify the former spontaneously. A reward was given whichever face was touched to avoid any possible learning effect. Horses touched the faces of keepers significantly more than chance, whether it was their current keeper or one they had not seen for six months (t = 3.65; p < 0.004 and t = 6.24; p < 0.0001). Overall, these results show that horses have advanced human face-recognition abilities and a long-term memory of those human faces.

Lateral thrust in all-steel buckling-restrained braces: Experimental and FEM results

The lateral thrust — the total contact force exerted by the buckled core of a buckling-restrained brace (BRB) against its restraining profiles — in bolted all-steel BRBs was studied mainly by means of laboratory tests. The primary purpose was to obtain a better understanding of the “predictability” of the lateral thrust for a given set of boundary conditions. Eleven nominally identical all-steel, reduced-scale BRB samples were subjected to the same cyclic loading, and data were recorded concerning (i) the value of the total lateral thrust, (ii) the relative slip between the buckled core and the restraining surfaces, and (iii) the longitudinal strain at opposite faces of the buckled core. A very high scatter among the peak values of the lateral thrust was observed. The experimental results concerning points (ii) and (iii) were integrated by the results of a refined 3D Finite Element analysis. Very little core-restraining profiles relative slip was observed in the tests. The elastic-plastic core buckling seems to be of the von Kármán type, i.e., with simultaneous loading and unloading at the opposite sides of the core.

Investigation of the frequency dependence of the electrical conductivity in PZT piezoceramics

Purpose. To investigate the frequency dependence of the electrical conductivity in piezoelectric ceramics based on solid solutions of lead-zirconate titanate oxides.Methodology. To obtain the frequency dependence of the electrical conductivity in piezoelectric ceramics based on solid solutions of lead-zirconate titanate oxides, we used a technique for measuring the resistance of a sample with electrodes deposited on its opposite faces. Using the obtained resistance value, the value of the electrical conductivity of the sample was calculated at various frequencies.Findings. The frequency dependence of the specific electrical conductivity in PZT-22 piezoceramics based on solid solutions of lead-zirconate titanate oxides in the frequency range of 0 &lt; ν &lt; 60 kHz has been obtained by the authors. The specific electrical conductivity in PZT-22 piezoceramics increased over the entire range of frequencies studied. A sharp increase in specific electrical conductivity was observed at frequencies up to 20 kHz. At frequencies of ν &gt; 20 kHz the increase in specific electrical conductivity ceased and at frequencies of ν &gt; 30 kHz its value reached saturation. The maximum value of specific electrical conductivity γ = 0.55 . 10-6 Ohm-1.m-1 was obtained at a frequency of 60 kHz. The frequency dependence of the specific electrical conductivity in PZT-22 piezoceramics in the frequency range of 0 &lt; ν &lt; 60 kHz is analyzed. It was found that the specific electrical conductivity in PZT-22 piezoceramics increases according to a power law in the frequency range of 0 &lt; ν &lt; 10 kHz. The mechanism of changing the electrical conductivity in PZT piezoceramics with increasing frequency of the electric field is discussed. A formula is obtained that satisfactorily describes the experimental dependence of the specific electrical conductivity in PZT-22 piezoceramics on the frequency of an alternating voltage in the frequency range of 0 &lt; ν &lt; 10 kHz and which corresponds to the power law of A. Ioncher. The specific electrical conductivity in the unpolarized PZT-19 piezoceramics increases in the frequency range of 0 &lt; ν &lt; 100 kHz. In the frequency range of 0 &lt; ν &lt; 20 kHz a power law dependence is observed and at frequencies of ν &gt; 20 kHz a power law is violated and the specific electrical conductivity gradually increases without reaching saturation. Originality. The frequency dependence of the electrical conductivity in PZT-22 piezoceramics in the frequency range of 0 &lt; ν &lt; 60 kHz is studied. It is established that the specific electrical conductivity in PZT-22 piezoceramics increases with increasing frequency of the electric field and in the frequency range of 0 &lt; ν &lt; 10 kHz, the nature of its change corresponds to the power law of A. Ioncher. The mechanism of change in electrical conductivity is due to the hopping conductivity of ions and polarons in a dielectric and is explained by the delay of slow polarization mechanisms. The nature of the dependence of the specific electrical conductivity in PZT-19 piezoelectric ceramics is due to the fact that polarization processes do not make a noticeable contribution to the dispersion of the electrical conductivity of unpolarized piezoceramics and the delay of slow polarization mechanisms is not observed.Practical value. When using piezoceramics based on solid solutions of lead-zirconate titanate oxides, it is necessary to take into account the significant dependence of its electrical conductivity on the frequency of an alternating electric field. The research results can be used to study the mechanism of electrical conductivity of piezoceramic materials based on solid solutions of lead-zirconate titanate oxides, which are used in electrical and electronic products under the influence of alternating electric fields of various frequencies.

Biplanar Epitaxial AlN/SiC/(n, p)SiC Structures for High-Temperature Functional Electronic Devices

We investigate the possibility of integration of epitaxial SiC and AlN technologies using opposite faces of the common SiC substrate (AlN epitaxy is performed at the final stage), preserving the initial quality of the preliminarily prepared SiC layers. In particular, we study the influence of AlN heteroepitaxy and accompanying elastic stresses on the redistribution of a doping impurity in SiC layers, as well as the transformation of the local values of the breakdown voltage of barrier diodes, which is associated with this process. As the diagnostic procedure in studying possible negative consequences of durable growth (about 3 h, 60 μm), we have measured reverse branches of the current–voltage characteristics of surface-barrier diode matrices of the Au–SiC type, which have intentionally been formed before and immediately after AlN epitaxy and then removed after the appropriate measuring procedure. Statistical processing of the breakdown voltages (including the calculation of histograms) shows that the variation of mean values and dispersion for the n- as well as p-layers is insignificant.

Standardization of the method of magnetostriction measurement of grain-oriented electrical steel strip and sheet

Standardization of the method of measurement of AC magnetostriction characteristics of grain-oriented electrical steel strip and sheet by means of a single sheet tester and an optical sensor, i.e. IEC 60404-17 Ed.1 [1], has been promoted in the IEC/TC68/WG2 to meet the demand of transformer industry. The relationship between the magnetostriction characteristics of grain-oriented electrical steel and transformer noise is complicated and yet not fully understood. One of basic problems has been the lack of a standard for the magnetostriction measurements. The measurement requires detection of slight vibration of the test specimen at a resolution of 0.01 μm/m or better. In order to ensure this resolution, not only magnetic aspects but also mechanical aspects of the test apparatus, e.g. the influence of friction and external vibrations, have to be specified. The size of test specimen is restricted to 100 mm × 500 mm. The flux closer is a vertical single yoke or a horizontal double yoke. In order to avoid the influence of friction and vibration, no weight is put on the test specimen except an optical target and a clamp to fix the test specimen to the test apparatus. Also, no weight is connected to the end of test specimen to prevent additional vibration modes. The optical target is low mass and made of non-magnetic and non-conductive materials. The optical target and the clamp are placed between opposite pole faces of the yoke. In order to realize a low and constant friction coefficient, an insertion sheet with a thin fluorine resin-impregnated glass cloth adhesive film on its upper surface is placed under the test specimen. A round robin comparison using different test setups in accordance with the draft of standard was carried out.

Double Hangman Iron Porphyrin and the Effect of Electrostatic Nonbonding Interactions on Carbon Dioxide Reduction.

Hangman porphyrins influence the reaction rates of small molecule activation by positioning a functional group in the secondary coordination sphere of the metal center. Electrocatalysis by hangman porphyrins has examined only one face modification of the macrocycle with a hanging group, thus allowing for circumvention of secondary sphere effects by reaction of the small molecule on the opposite face of the hangman cleft. We now report the synthesis and characterization of a double hangman Fe porphyrin in which both faces of the macrocycle are modified with a hanging group. With this double hangman architecture, we are able to unequivocally examine the role of electrostatic interactions on the carbon dioxide reduction reaction (CO2RR) and show that CO2RR rates are significantly attenuated, consistent with the initial reduction of CO2 to generate the anion, whose binding is diminished within the negatively charged carboxylic groups of the hangman cleft. The results demonstrate the pronounced role that nonbonding electrostatic interactions may play in CO2RR and highlight the need to manage deleterious electrostatic interactions during catalytic turnover.

Janus-like asymmetrically oxidized graphene: Facile synthesis and distinct liquid crystal alignment at the oil/water interface

Janus graphene oxide (GO) usually refers to a unique two-dimensional material with asymmetric surface chemistries on opposite faces of the sheets. Herein, we propose a facile and efficient method to fabricate Janus-like GO (JGO) with a novel asymmetric structure along the faces of the sheets. Unlike the traditional post-synthesis of double-faced Janus GO based on pre-prepared GO, the novel JGO with a randomly distributed asymmetric oxidation structure along the sheet face can be achieved by a simple ultrasonic treatment on partially oxidized graphene. The asymmetric oxidation structure along the sheet face of our Janus GO was confirmed by confocal micro-Raman imaging and analysis of height profiles by atomic force microscopy. Due to the asymmetric oxidation structure, the as-prepared JGO has amphiphilic characteristics, with hydrophilicity on one side of the sheet and hydrophobicity on the other side, leading to an eyelash-like liquid crystal alignment at the oil/water interface. The perpendicular alignment rather than the parallel orientation behavior of GO liquid crystals at the oil/water interface further confirms the asymmetric structure of our JGO along the face graphene sheets. The simple approach and a new class of JGO proposed herein provide a new insight into understanding the asymmetric chemistry of graphene.

Concurrence of tetrahedral cevians associated with triangle centers

It is well known that the center of mass of a tetrahedron is the intersection of the line segments that join its vertices to the centers of mass of the opposite faces, and that a similar statement holds for simplices in higher dimensions. This paper addresses the question whether this nice inductive property of the center of mass also holds for other centers. It proves that the center of mass is the only center that has this property, and investigates in detail the situation for the other well known centers, namely, the Gergonne center, the Nagel center, the Lemoine center, the incenter, the orthocenter, the Fermat-Torricelli center, and the circumcenter. Some questions for further research are raised.

Could Personal Resources Influence Work Engagement and Burnout? A Study in a Group of Nursing Staff

The aim of this research is twofold. First, to identify the role of personal resources on burnout and work engagement in nursing staff and second to evaluate whether these last two concepts are or not, opposite faces of the same construct. Personal resources are understood as individuals’ aspects that make people more confident to control their environment successfully. This study used a cross-sectional approach with a sample composed of 219 Colombian nursing personnel all of them were women. In line with our predictions, personal resources were positively related to employees’ work engagement ( rxy = .40) and negatively to burnout ( rxy = -.51), as well as engagement and burnout showed to be different constructs that are inversely related ( rxy = -.95). The greater inverse correlation between personal resources and burnout seems to indicate that personal resources could be an important protective factor for nursing staff. Since personal resources can be developed, these findings have important implications for the human resource management in the health care settings. Due to the complexity of health work environment, further research needs to find more evidence to understand the role of personal resources in these environments.

Спектроскопия слоев на плоскопараллельных подложках

Integral expressions for the reflectance and transmittance spectra of the structure consisted of two thin layers deposited on opposite faces of a plane-parallel substrate at oblique illumination of the structure with partially coherent light are obtained. As a result of the asymptotic analysis of the integrals, approximate analytical formulae are established for calculating the indicated spectra, convenient for use in solving inverse spectrophotometry problems. An aluminum doped zinc oxide layer deposited on a glass substrate is studied. The spectra of the refractive index and absorption coefficient of the layer and the substrate, as well as the thickness of the layer, are determined by processing the reflectance and transmission spectra of the structure, measured for s- and p- polarized waves at two angles of light incidence. The found parameters are used in computational experiments to estimate the applicability limits of the formulated approximations.

Bressanone, via Castellano, abitato del Bronzo finale: evidenze di strutture di combustione?

Excavations carried out in 2002-2003 by the Office of Archaeological Heritage of Bolzano in Bressanone - Via Castellano, have allowed us to investigate a large settlement area (2000 m2) dating back to the Final Bronze Age. Among other features, three pits with heating traces on bottom and walls and a great amount of daub fragments in the filling have been found. Most of the daub fragments have flat or concave finished surfaces and on the opposite face the impressions of a support frame made up of small-diameter closely intertwined plant elements, with transversal elements of greater diameter (2-3 cm). It is possible that the daub fragments were relative to some kind of wattle and daub structures complementary to the firing pits.

ПРОИЗВОДНАЯ ФУНКЦИОНАЛА ЭНЕРГИИ В ЗАДАЧЕ О РАВНОВЕСИИ ПЛАСТИНЫ КИРХГОФА ––– ЛЯВА С УСЛОВИЯМИ НЕПРОНИКАНИЯ ДЛЯ ИЗВЕСТНОЙ КОНФИГУРАЦИИ ИЗГИБА

Рассматриваются вариационные задачи теории упругости в области с разрезом, описывающие равновесие пластины с трещиной. Предполагается, что под действием определенных заданных нагрузок пластина имеет деформации с определенной заранее известной конфигурацией кромок вблизи трещины. На кривой в срединной плоскости, соответствующей трещине, заданы краевые условия в виде двух неравенств. В предположении, что параметр описывает возмущение трещины, находится производная функционала энергии по отношению к . Результаты получены для новых математических моделей с новыми краевыми условиями, описывающими специальный характер контактного взаимодействия кромок пластины. Equilibrium problems for elastic plates with a rectilinear crack are studied. It is assumed that under the action of certain given loads, plates have deformations with a certain predetermined configuration of edges near the crack. On the crack curve, we impose a nonlinear boundary condition as an inequality describing the nonpenetration of the opposite crack faces. Assuming that the parameter describes the crack perturbation, the derivative of the energy functional with respect to is found. The results are obtained for new mathematical models with new nonlinear boundary conditions describing special character of the mechanical contact interaction of the plate edges.

Effect of porosities on brazed martensitic steel tensile properties: 2D and 3D pre-mortem vs post-mortem characterizations

A quantitative investigation of the porosity and its effects on mechanical properties was conducted on brazed materials presenting macroscopically brittle behavior with various defect levels. Three different techniques for evaluating the porosity and the fracture mechanisms were compared: (i) pre-mortem X-ray computed tomography (XCT), (ii) post-mortem laser scanning confocal microscopy (LSCM), and (iii) post-mortem scanning electron microscopy (SEM). The apparent surface area of the pores was evaluated by segmenting the height maps produced by LSCM and the electron backscattered images produced by SEM. The results show good agreement for different porosity levels. The LSCM height maps for opposite fracture faces were virtually stitched together in order to reconstruct three-dimensional (3D) images of the whole brazed joints. These proved to be similar to the XCT 3D segmented images, yet with some discrepancies due to local plastic deformation. Quantitative volume fraction and spatial distribution of pores were assessed as well as the identification of fracture mechanisms. Interestingly, it was noted that two specimens with different ultimate tensile strengths presented the same porosity amount, but different distributions. Two distinctive features were identified in the broken specimens: plastically teared pillars and walls that were separating the pores before fracture, and plateaus of approximately constant height with micro-sized dimples showing interfacial fracture. Although the specimens exhibited a macroscopic brittle behavior, these features are characteristic of ductile fracture. The most probable scenario for fracture was conjectured as follows: (i) Final fracture occurs in the near-surface region of the samples and conversely early damage develops in the volume, (ii) Interfacial fracture within plateaus is responsible of the rupture/strength of the brazed specimen but detrimental effect is induced by the tearing if highly voided regions are present in the joint.

Feasibility of ground state spin switching in a molecular analogue of the mixed-metal oxides with the perovskite structure

The carboxylate substitution reaction between the reported all-benzoate complex [Ce3Mn8O8(PhCO2)18(PhCO2H)2] (1) and 2-Cl-benzoic acid has led to isolation of [Ce3Mn8O8(2-Cl-PhCO2)15.3(PhCO2)2.7(H2O)2] (2). The structures of 1 and 2 are very similar, both containing a tetragonally-elongated MnIII8 cuboid with a CeIV at its center and two CeIII attached to opposite faces, but 2 shows extensive disorder in the ligands and the Cl atom positions and occupancies. Variable-temperature (T) solid-state dc and ac magnetic susceptibility data for 2 are significantly different from those for 1 and are assigned as due to small ligand-induced structural perturbation of the core that has brought an A-type antiferromagnetic (AF) excited state much closer to the C-type AF ground state. Fits of the dc χMT vs T data support this interpretation but due to the ligand disorder in 2, a more definitive description of the lowest energy spin states of 2 is not possible. Nevertheless, these results provide important support for the feasibility of ground state spin switching by ligand-induced core perturbation (‘chemical pressure’) in this family, and they encourage further studies.

A micromechanical model based on hypersingular integro-differential equations for analyzing micro-crazed interfaces between dissimilar elastic materials

The current work models a weak (soft) interface between two elastic materials as containing a periodic array of micro-crazes. The boundary conditions on the interfacial micro-crazes are formulated in terms of a system of hypersingular integro-differential equations with unknown functions given by the displacement jumps across opposite faces of the micro-crazes. Once the displacement jumps are obtained by approximately solving the integro-differential equations, the effective stiffness of the micro-crazed interface can be readily computed. The effective stiffness is an important quantity needed for expressing the interfacial conditions in the spring-like macro-model of soft interfaces. Specific case studies are conducted to gain physical insights into how the effective stiffness of the interface may be influenced by the details of the interfacial micro-crazes.

Discontinuous Galerkin isogeometric analysis for segmentations generating overlapping regions

In the Isogeometric Analysis (IGA) framework, the computational domain has very often a multipatch representation. The multipatch domain can be obtained by a volume segmentation of a boundary represented domain, e.g. provided by a Computer Aided Design model. Typically, small gaps and overlapping regions can appear at the patch interfaces of such multipatch representations. In the current work, we consider multipatch representations having only small overlapping regions between the patches. We develop a Discontinuous Galerkin (DG)-IGA method that can be immediately applied to these representations. Our method appropriately connects the fluxes of the one face of the overlapping region with the flux of the opposite face. We provide a theoretical justification of our approach by splitting the whole error into two components: the first is related to the incorrect representation of the patches (consistency error) and the second to the approximation properties of the IGA space. We show bounds for both components of the error. We verify the theoretical error estimates in a series of numerical examples.

Localized divertor leakage measurements using isotopic tungsten sources during edge-localized mode-y H-mode discharges on DIII-D

Experiments carried out on DIII-D using a novel setup of isotopic tungsten (W) sources in the outer divertor have characterized how the W leakage from this region depends on both the exact source location and edge-localized mode (ELM) behavior. The sources are toroidally-symmetric and poloidally-localized to two regions: (1) the outer strike point (OSP) with natural abundance of W isotopes; and (2) the far-target with highly-enriched 182W isotopes. With the use of a dual-faced collector probe (CP) in the main scrape-off layer (SOL) near the outside midplane and source-rate spectroscopy, a proxy for divertor impurity leakage is developed. Using this proxy, it is found that for the OSP W location, there is a nearly linear increase of leakage with the power across the separatrix (), which is consistent with the effect of an increased upstream ion temperature parallel gradient force in the near-SOL; trends in the pedestal density and collisionality are also seen. Conversely, it is found that for the far-target W location leakage falls off rapidly as increases and ELM size decreases, which is suggestive that ELM size plays a role in the leakage from this location. Indications for main SOL W contamination is evidenced by the measurement of large deposition asymmetries on the two opposite CP faces. These measurements are coupled with interpretive modeling showing SOL W accumulation near the separatrix furthest from both targets driven by forces parallel to the magnetic field. This experimental setup, together with the target and upstream W measurements, provides information on the transport from different divertor W source locations and leakage. These studies help to elucidate the physics driving divertor impurity source rates and leakage, with and without ELMs, and provide better insight on the link in the chain connecting wall impurity sources to core impurity levels in magnetic fusion devices.

Ligand-Dependent Luminescence Properties of Lanthanide-Titanium Oxo Clusters.

A series of lanthanide-titanium oxo clusters (LnTOCs), Ln2Ti8-Ac, Ln2Ti8-p-Toluic, and Ln2Ti8-Anthra (Ln = Eu and Tb), were prepared based on acetic acid (HAc), p-toluic acid (Hp-Toluic), and anthracene-9-carboxylic acid (HAnthra). Crystal structural analysis showed that these clusters possess the same metal topology framework, in which eight Ti4+ ions form a cube and two Ln3+ ions are located on the opposite faces of the cube. The luminescence investigation discovered that the Eu2Ti8-Ac displays the highest quantum yields with 15.6%, and the conjugation effect of ligand substituents can lower the triplet state energy of ligands, thus regulating the luminescence quantum yield of the Ln2Ti8 clusters. These results suggest that the triplet excited-state energy of the ligands should match well with the energy levels of Ln3+ to enhance the luminescence.

HKT1;5 Transporter Gene Expression and Association of Amino Acid Substitutions With Salt Tolerance Across Rice Genotypes.

Plants need to maintain a low Na+/K+ ratio for their survival and growth when there is high sodium concentration in soil. Under these circumstances, the high affinity K+ transporter (HKT) and its homologs are known to perform a critical role with HKT1;5 as a major player in maintaining Na+ concentration. Preferential expression of HKT1;5 in roots compared to shoots was observed in rice and rice-like genotypes from real time PCR, microarray, and RNAseq experiments and data. Its expression trend was generally higher under increasing salt stress in sensitive IR29, tolerant Pokkali, both glycophytes; as well as the distant wild rice halophyte, Porteresia coarctata, indicative of its importance during salt stress. These results were supported by a low Na+/K+ ratio in Pokkali, but a much lower one in P. coarctata. HKT1;5 has functional variability among salt sensitive and tolerant varieties and multiple sequence alignment of sequences of HKT1;5 from Oryza species and P. coarctata showed 4 major amino acid substitutions (140 P/A/T/I, 184 H/R, D332H, V395L), with similarity amongst the tolerant genotypes and the halophyte but in variance with sensitive ones. The best predicted 3D structure of HKT1;5 was generated using Ktrab potassium transporter as template. Among the four substitutions, conserved presence of aspartate (332) and valine (395) in opposite faces of the membrane along the Na+/K+ channel was observed only for the tolerant and halophytic genotypes. A model based on above, as well as molecular dynamics simulation study showed that valine is unable to generate strong hydrophobic network with its surroundings in comparison to leucine due to reduced side chain length. The resultant alteration in pore rigidity increases the likelihood of Na+ transport from xylem sap to parenchyma and further to soil. The model also proposes that the presence of aspartate at the 332 position possibly leads to frequent polar interactions with the extracellular loop polar residues which may shift the loop away from the opening of the constriction at the pore and therefore permit easy efflux of the Na+. These two substitutions of the HKT1;5 transporter probably help tolerant varieties maintain better Na+/K+ ratio for survival under salt stress.