Electrostatically tunable interaction of CO2 with MgO surfaces and chemical switching: first-principles theory.

Electric field-assisted CO2 capture using solid adsorbents based on basic oxides can immensely reduce the required energy consumption compared to the conventional processes of temperature or pressure swing adsorption. In this work, we present first-principles density functional theoretical calculations to investigate the effects of an applied external electric field (AEEF) within the range from -1 to 1 V Å-1 on the CO2 adsorption behavior on various high and low-index facets of MgO. When CO2 is strongly adsorbed on MgO surfaces to form carbonate species, the coupling of electric fields with the resulting intrinsic dipole moment induces a 'switch' from a strongly chemisorbed state to a weakly chemisorbed or physisorbed state at a critical value of AEEF. We demonstrate that such 'switching' enables access to different metastable states with variations in the AEEF. On polar MgO(111) surfaces, we find a distinct feature of the adsorptive dissociation of CO2 towards the formation of CO in contrast to that on the non-polar MgO(100) and MgO(110) surfaces. In some cases, we observe broken inversion symmetry because of the AEEF that results in induced polarity at the interaction site of CO2 on MgO surfaces. Our results provide fundamental insights into the possibility of using AEEFs in novel solid adsorbent systems for CO2 capture and reduction.

Exogenous Application of Calcium Ameliorates Salinity Stress Tolerance of Tomato (Solanum lycopersicum L.) and Enhances Fruit Quality.

Tomato is affected by various biotic and abiotic stresses, especially salinity, which drastically hinders the growth and yield of tomato. Calcium (Ca) is a vital macronutrient which plays physiological and biochemical roles in plants. Hence, we studied the protective roles of Ca against salinity stress in tomato. There were eight treatments comprising control (nutrient solution), 5 mM Ca, 10 mM Ca, 15 mM Ca, 12 dS m-1 NaCl, 12 dS m-1 NaCl + 5 mM Ca, 12 dS m-1 NaCl + 10 mM Ca and 12 dS m-1 NaCl + 15 mM Ca, and two tomato varieties: BARI tomato-2 and Binatomato-5. Salinity significantly decreased the plant-growth and yield attributes, relative water content (RWC), photosynthetic pigments (SPAD value) and the uptake of K, Ca and Mg in leaves and roots. Salinity-induced oxidative stress was present in the form of increased Na+ ion concentration, hydrogen peroxide (H2O2) content and lipid peroxidation (MDA). Ca application reduced oxidative stress through the boosting of antioxidant enzymatic activity. Exogenous Ca application enhanced proline and glycine betaine content and reduced Na+ uptake, which resulted in the inhibition of ionic toxicity and osmotic stress, respectively. Hence, Ca application significantly increased the growth and yield attributes, RWC, SPAD value, and uptake of K, Ca and Mg. Calcium application also had a significant effect on the fruit quality of tomato and the highest total soluble solid, total sugar, reducing sugar, ß-carotene, vitamin C and juice pH were found for the combined application of NaCl and Ca. Therefore, application of Ca reversed the salt-induced changes through increasing osmoprotectants, activation of antioxidants enzymes, and by optimizing mineral nutrient status.

Exploring a low temperature glassy state, exchange bias effect, and high magnetic anisotropy in Co2C nanoparticles.

It is interesting to explore the connections between the exchange bias effect (EBE) and magnetic anisotropy (MA). It is often found that materials exhibiting a strong EBE also have enhanced MA. Here we explore 40 nm diameter Co2C nanoparticles (NPs) that exhibit ferromagnetism with a blocking temperature exceeding 300 K. We report the first observation of EBE in these Co2C NPs below 50 K. The effect arises from the exchange coupling of frozen ferromagnetic spins with a freely rotatable spin component. The dynamics of the freely rotatable component freezes in a temperature range between 5 K to 20 K resulting in low-temperature coexistence of a glassy behavior along with ferromagnetism. In fact, Co2C displays a unique separation of onset temperatures of spin freezing (∼20 K), vanishing of EBE (∼50 K), and magnetic blocking (⩾450 K). Our calculations show that Co2C NPs have a core-shell structure. Our study suggests that modifying chemical co-ordination in the shell is one of the effective routes to manipulating MA compared to manipulating EBE.

Emotional intelligence and perceived stress among undergraduate students of arts and science colleges in Puducherry, India: A cross-sectional study.

BACKGROUND: The concept of emotional intelligence has gained great popularity in the last few decades. With significant rise in stress and other emotional disturbances among students, it becomes necessary to determine whether high emotional intelligence could help manage perceived stress better. This study aims to assess emotional intelligence and perceived stress among undergraduate students of Arts and Science colleges, to determine the association of emotional intelligence with perceived stress, academic performance, and selected socio-demographic factors. METHODS AND MATERIAL: Using multistage sampling, 720 students aged 18 years and above were selected from four colleges in Puducherry. Emotional intelligence and perceived stress were assessed using standard self-administered questionnaires "The Schutte Self-Report Emotional Intelligence Test (SEIT)" and "Perceived Stress Scale (PSS-14)," respectively. RESULTS: The median (IQR) Emotional Intelligence score and Perceived Stress score were 127 (114-137) and 43 (39-47), respectively. The study was not able to establish a significant association between emotional intelligence and perceived stress. A weak significant correlation existed between emotional intelligence and academic performance. Multiple variable analysis revealed gender, year of study, volunteering with youth organizations, and mother's occupation to be significantly associated with emotional intelligence (p < 0.05). CONCLUSIONS: Women, final year students and those who volunteered with youth organizations had higher emotional intelligence. Children of mothers who were employed in knowledge-intensive occupations were more emotionally intelligent. Academic performance had a weak positive significant correlation with emotional intelligence.

The Na+ pump Ena1 is a yeast epsin-specific cargo requiring its ubiquitylation and phosphorylation sites for internalization.

It is well known that in addition to its classical role in protein turnover, ubiquitylation is required for a variety of membrane protein sorting events. However, and despite substantial progress in the field, a long-standing question remains: given that all ubiquitin units are identical, how do different elements of the sorting machinery recognize their specific cargoes? Our results indicate that the yeast Na+ pump Ena1 is an epsin (Ent1 and Ent2 in yeast)-specific cargo and that its internalization requires K1090, which likely undergoes Art3-dependent ubiquitylation. In addition, an Ena1 serine and threonine (ST)-rich patch, proposed to be targeted for phosphorylation by casein kinases, was also required for its uptake. Interestingly, our data suggest that this phosphorylation was not needed for cargo ubiquitylation. Furthermore, epsin-mediated internalization of Ena1 required a specific spatial organization of the ST patch with respect to K1090 within the cytoplasmic tail of the pump. We hypothesize that ubiquitylation and phosphorylation of Ena1 are required for epsin-mediated internalization.

Designing rare earth free permanent magnets: insights from small Co clusters.

With the ultimate goal of rational design of permanent magnets without rare earth elements, we study the magnetic properties of Co4 clusters doped with six different group 14 and group 15 elements, using first principles electronic structure methods, based on density functional theory. For the first time, low energy isomers and magnetic moments of pure Co4 and Co6 clusters, and the doped clusters are identified through a global search employing an evolutionary algorithm. The magnetic anisotropy energy (MAE) of these clusters is then calculated. No correlation is found between the type of dopant atom and MAE. Through further analyses we establish that MAE is largely determined by the sum of absolute values of the spin moments on the individual atoms, and the HOMO-LUMO gap of the system. The importance of these in designing new permanent magnetic materials is discussed.

A randomized, double-blind trial of amorolfine 0.25% cream and sertaconazole 2% cream in limited dermatophytosis.

BACKGROUND: Dermatophytosis is becoming increasingly unresponsive to conventional antifungals. Newer topical antifungals may be more effective in these patients. AIMS: To evaluate and compare the efficacy and safety of amorolfine 0.25% cream and sertaconazole 2% cream in limited tinea cruris/corporis. METHODS: A single-center, randomized (1:1), double-blind, parallel group, active-controlled trial (CTRI/2014/12/005246) was performed. Sixty-six untreated adults with acutely symptomatic tinea cruris/corporis were included in the study. All patients had limited cutaneous involvement and were KOH mount positive. Group A received amorolfine 0.25% cream, and group B received sertaconazole 2% cream twice daily application to the lesions for 4 weeks. After the baseline visit, four follow-up visits were carried out. The outcome measures for effectiveness were clinical and mycological cure. Safety parameters studied were treatment-emergent adverse events and changes in routine laboratory parameters. RESULTS: Both sertaconazole and amorolfine significantly reduced symptoms (P < 0.001) in both groups. However, improvement in symptoms (pruritus, burning sensation, erythema, scaling and crusting) was significantly greater in the sertaconazole group at every follow-up visit. Sertaconazole cream was also more effective than amorolfine cream in reducing the number of lesions (P = 0.002 at 12 weeks) and improving the Dermatology Life Quality Index (P < 0.001) at all the follow-up visits. Adverse events were similar in the two groups (P = 0.117). Fungal cultures became negative in 92.3% of the sertaconazole group as compared to 80% in the amorolfine group (P = 0.010). LIMITATIONS: Antifungal susceptibility testing could not be done. CONCLUSION: Sertaconazole 2% is superior to amorolfine 0.25%, both in terms of effectiveness and tolerability. Improvement can be appreciated from second week onwards.

The Information Content of Glutamine-Rich Sequences Define Protein Functional Characteristics.

The presence of abnormally expanded glutamine (Q) repeats within specific proteins (e.g., huntingtin) are the well-established cause of several neurogenerative diseases, including Huntington disease and spinocerebellar ataxias. However, the impact of "expanded Q" stretches on the protein function is not well-understood, mostly due to lack of knowledge about the physiological role of Q repeats and the mechanism by which these repeats achieve functional-specificity. Indeed, is intriguing that regions with such low complexity (low information content) can display exquisite functional specificity. Prompting the question: where is this information stored? Applying biochemical/structural constraints and statistical analysis of protein composition we identified Q-rich (QR) regions present in coiled coils of yeast transcription factors and endocytic proteins. Our analysis indicated the existence of non-Q amino-acids differentially enriched or excluded from QR regions in one protein group versus the other. Importantly, when the non-Q amino-acids from an endocytic protein were exchanged by the ones enriched in QR from transcription factors, the resulting protein was unable to localize to the plasma membrane and was instead found in the nucleus. These results indicate that while QR repeats can efficiently engage in binding, the non-Q amino-acids provide essential specificity information. We speculate that coupling low complexity regions with information-intensive determinants might be a strategy used in many protein systems involved in different biological processes.

Inpatient Dermatology: Characteristics of Patients and Admissions in a Tertiary Level Hospital in Eastern India.

INTRODUCTION: Dermatology is primarily a non-acute, outpatient-centered clinical specialty, but substantial number of patients need indoor admission for adequate management. Over the years, the need for inpatient facilities in Dermatology has grown manifold; however, these facilities are available only in some tertiary centers. AIMS AND OBJECTIVES: To analyze the characteristics of the diseases and outcomes of patients admitted in the dermatology inpatient Department of a tertiary care facility in eastern India. MATERIALS AND METHODS: We undertook a retrospective analysis of the admission and discharge records of all patients, collected from the medical records department, admitted to our indoor facility from 2011 to 2014. The data thus obtained was statistically analyzed with special emphasis on the patient's demographic profile, clinical diagnosis, final outcome, and duration of stay. RESULTS AND ANALYSIS: A total of 375 patients were admitted to our indoor facility during the period. Males outnumbered females, with the median age in the 5th decade. Immunobullous disorders (91 patients, 24.27%) were the most frequent reason for admissions, followed by various causes of erythroderma (80 patients, 21.33%) and infective disorders (73 patients, 19.47%). Other notable causes included cutaneous adverse drug reactions, psoriasis, vasculitis, and connective tissue diseases. The mean duration of hospital stay was 22.2±15.7 days; ranging from 1 to 164 days. Majority of patients (312, 83.2%) improved after hospitalization; while 29 (7.73%) patients died from their illness. About 133 patients (35.64%) required referral services during their stay, while 8 patients (2.13%) were transferred to other departments for suitable management. CONCLUSION: Many dermatoses require inpatient care for their optimum management. Dermatology inpatient services should be expanded in India to cater for the large number of cases with potentially highly severe dermatoses.

Internalization of Heterologous Sugar Transporters by Endogenous α-Arrestins in the Yeast Saccharomyces cerevisiae.

When expressed in Saccharomyces cerevisiae using either of two constitutive yeast promoters (PGK1prom and CCW12prom), the transporters CDT-1 and CDT-2 from the filamentous fungus Neurospora crassa are able to catalyze, respectively, active transport and facilitated diffusion of cellobiose (and, for CDT-2, also xylan and its derivatives). In S. cerevisiae, endogenous permeases are removed from the plasma membrane by clathrin-mediated endocytosis and are marked for internalization through ubiquitinylation catalyzed by Rsp5, a HECT class ubiquitin:protein ligase (E3). Recruitment of Rsp5 to specific targets is mediated by a 14-member family of endocytic adaptor proteins, termed α-arrestins. Here we demonstrate that CDT-1 and CDT-2 are subject to α-arrestin-mediated endocytosis, that four α-arrestins (Rod1, Rog3, Aly1, and Aly2) are primarily responsible for this internalization, that the presence of the transport substrate promotes transporter endocytosis, and that, at least for CDT-2, residues located in its C-terminal cytosolic domain are necessary for its efficient endocytosis. Both α-arrestin-deficient cells expressing CDT-2 and otherwise wild-type cells expressing CDT-2 mutants unresponsive to α-arrestin-driven internalization exhibit an increased level of plasma membrane-localized transporter compared to that of wild-type cells, and they grow, utilize the transport substrate, and generate ethanol anaerobically better than control cells. IMPORTANCE: Ethanolic fermentation of the breakdown products of plant biomass by budding yeast Saccharomyces cerevisiae remains an attractive biofuel source. To achieve this end, genes for heterologous sugar transporters and the requisite enzyme(s) for subsequent metabolism have been successfully expressed in this yeast. For one of the heterologous transporters examined in this study, we found that the amount of this protein residing in the plasma membrane was the rate-limiting factor for utilization of the cognate carbon source (cellobiose) and its conversion to ethanol.

X-linked Ichthyosis Presenting as Erythroderma: A Rare Case.

X-linked ichthyosis is a rare form of dermatological disease and when it presents as erythroderma it is even rarer. History of consanguineous marriage and prolonged labor during birth of patient, generalized scaling which gets better in summer months, flexural involvement, cryptorchidism made a diagnosis of X-linked ichthyosis. We report this case because of its rarity as erythroderma.

RhoGTPase-binding proteins, the exocyst complex and polarized vesicle trafficking.

Cell polarity, the asymmetric distribution of proteins and lipids, is essential for a variety of cellular functions. One mechanism orchestrating cell polarity is polarized vesicle trafficking; whereby cargo loaded secretory vesicles are specifically transported to predetermined areas of the cell. The evolutionarily conserved exocyst complex and its small GTPase regulators play crucial roles in spatiotemporal control of polarized vesicle trafficking. In studies on neuronal membrane remodeling and synaptic plasticity, conserved mechanisms of exocyst regulation and cargo recycling during polarized vesicle trafficking are beginning to emerge as well. Recently, our lab demonstrated that RhoGTPase-binding proteins in both yeast (Bem3) and mammals (Ocrl1) are also required for the efficient traffic of secretory vesicles to sites of polarized growth and signaling. Together with our studies, we highlight the evolutionary conservation of the basic elements essential for polarized vesicle traffic across different cellular functions and model systems. In conclusion, we emphasize that studies on RhoGTPase-binding proteins in these processes should be included in the next level of investigation, for a more complete understanding of their hitherto unknown roles in polarized membrane traffic and exocyst regulation.

Bem3, a Cdc42 GTPase-activating protein, traffics to an intracellular compartment and recruits the secretory Rab GTPase Sec4 to endomembranes.

Cell polarity is essential for many cellular functions including division and cell-fate determination. Although RhoGTPase signaling and vesicle trafficking are both required for the establishment of cell polarity, the mechanisms by which they are coordinated are unclear. Here, we demonstrate that the yeast RhoGAP (GTPase activating protein), Bem3, is targeted to sites of polarized growth by the endocytic and recycling pathways. Specifically, deletion of SLA2 or RCY1 led to mislocalization of Bem3 to depolarized puncta and accumulation in intracellular compartments, respectively. Bem3 partitioned between the plasma membrane and an intracellular membrane-bound compartment. These Bem3-positive structures were polarized towards sites of bud emergence and were mostly observed during the pre-mitotic phase of apical growth. Cell biological and biochemical approaches demonstrated that this intracellular Bem3 compartment contained markers for both the endocytic and secretory pathways, which were reminiscent of the Spitzenkörper present in the hyphal tips of growing fungi. Importantly, Bem3 was not a passive cargo, but recruited the secretory Rab protein, Sec4, to the Bem3-containing compartments. Moreover, Bem3 deletion resulted in less efficient localization of Sec4 to bud tips during early stages of bud emergence. Surprisingly, these effects of Bem3 on Sec4 were independent of its GAP activity, but depended on its ability to efficiently bind endomembranes. This work unveils unsuspected and important details of the relationship between vesicle traffic and elements of the cell polarity machinery: (1) Bem3, a cell polarity and peripherally associated membrane protein, relies on vesicle trafficking to maintain its proper localization; and (2) in turn, Bem3 influences secretory vesicle trafficking.

Crystallographic analysis of the ENTH domain from yeast epsin Ent2 that induces a cell division phenotype.

Epsins are eukaryotic, endocytic adaptor proteins primarily involved in the early steps of clathrin mediated endocytosis. Two epsins exist in Saccharomyces cerevisiae, Ent1 and Ent2, with single epsin knockouts being viable, while the double knockout is not. These proteins contain a highly conserved Epsin N-terminal homology (ENTH) domain that is essential for cell viability. In addition, overexpression of the ENTH domain of Ent2 (ENTH2) was shown to play a role in cell division by interacting with the septin organizing, Cdc42 GTPase activating protein, Bem3, leading to increased cytokinesis failure. In contrast, overexpression of the ENTH domain of Ent1 (ENTH1) does not affect cytokinesis, despite being 75% identical to ENTH2. An ENTH2(N112D, S114E, E118Q) mutant that switches residues in loop 7 to those found correspondingly in ENTH1 was incapable of inducing the cytokinesis phenotype. In order to better understand the role of loop 7 in the ENTH2-induced phenotype at a molecular level, X-ray crystallography was used to elucidate the structures of yeast ENTH2(WT) and ENTH2(DEQ). Our results indicate that mutations did not affect the conformation of loop 7, but rather introduce an increased negative charge on a potential interaction interface. Morphological analysis of cells overexpressing ENTH2 loop 7 mutants showed that the cytokinesis failure phenotype was abolished by the single mutants N112D, E118Q, and to a lesser extent by S114E. Taken together, our results indicate that the interaction surface that contains loop 7 and the specific nature of these residues are crucial for ENTH2 involvement in cytokinesis. This research provides insight into a molecular mechanism by which ENTH2, but not ENTH1, overexpression in yeast leads to cell division defects. Structural data of WT and mutant ENTH2 domains along with in vivo phenotypic analysis of ENTH2 overexpressing cells indicate that the biochemical nature of three loop 7 residues is crucial for its role in cytokinesis.

Bem3: Filling the GAP between cell polarity and secretion.

A highly conserved member of the Rho family of small GTPases, Cdc42 functions as the "master regulator of cell polarity." It has been reported that for proper establishment and maintenance of cell polarity, Cdc42 regulates and requires vesicle trafficking. Importantly, we recently discovered that in budding yeast, vesicle trafficking also controls the localization and function of Bem3, a GTPase activating protein for Cdc42. Specifically, we observed that Bem3 partitioned between the plasma membrane and an internal membrane-bound compartment. This Bem3-containing compartment was present during extended periods of apical growth, required actin tracks for trafficking to polarized sites and functioned as a recycling station that was positioned at the junction of endocytic and secretory pathways. Strikingly, many of these features are reminiscent of the Spitzenkörper, a dynamic structure involved in polarized growth during hyphal development in several filamentous fungi. Furthermore, Bem3 was not merely a passive cargo but actively recruited the secretory Rab GTPase Sec4 to this Spitzenkörper-like compartment. Importantly, this function of Bem3 was independent of its GAP activity. Our work demonstrates the existence of a complementary regulation between Bem3, a regulator of Cdc42 signaling and Sec4, a key component of the secretory machinery.

The epsin protein family: coordinators of endocytosis and signaling.

The epsins are a conserved family of endocytic adaptors essential for cell viability in yeast and for embryo development in higher eukaryotes. Epsins function as adaptors by recognizing ubiquitinated cargo and as endocytic accessory proteins by contributing to endocytic network stability/regulation and membrane bending. Importantly, epsins play a critical role in signaling by contributing to epidermal growth factor receptor downregulation and the activation of notch and RhoGTPase pathways. In this review, we present an overview of the epsins and emphasize their functional importance as coordinators of endocytosis and signaling.

Analysis of the development of a morphological phenotype as a function of protein concentration in budding yeast.

Gene deletion and protein overexpression are common methods for studying functions of proteins. In this article, we describe a protocol for analysis of phenotype development as a function of protein concentration at population and single-cell levels in Saccharomyces cerevisiae. Although this protocol is based on the overexpression of a protein, it can easily be adapted for morphological phenotypes dependent on suppression of protein expression. Our lab is interested in studying the signaling properties of the endocytic adaptor protein epsin. To that purpose we used a dominant negative approach in which we over-expressed the conserved Epsin N-Terminal Homology (ENTH) domain in order to interfere with the functions of endogenous epsin-2 (Ent2 or YLR206W). We observed that overexpression of the ENTH domain of Ent2 (ENTH2) in wild type cells led to a cell division defect that is dependent on the mislocalization of a family of scaffolding proteins, septins.